| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Russell King | 5634 | 43.51% | 40 | 18.96% |
| Linus Walleij | 1284 | 9.92% | 11 | 5.21% |
| Andre Przywara | 1112 | 8.59% | 10 | 4.74% |
| Chanho Min | 772 | 5.96% | 3 | 1.42% |
| Lino Sanfilippo | 572 | 4.42% | 5 | 2.37% |
| Dave P Martin | 227 | 1.75% | 4 | 1.90% |
| Andrew Jackson | 165 | 1.27% | 5 | 2.37% |
| Greg Kroah-Hartman | 164 | 1.27% | 5 | 2.37% |
| Timur Tabi | 161 | 1.24% | 6 | 2.84% |
| Aleksey Makarov | 151 | 1.17% | 2 | 0.95% |
| Sumit Garg | 147 | 1.14% | 1 | 0.47% |
| Matthew Leach | 147 | 1.14% | 1 | 0.47% |
| Shawn Guo | 146 | 1.13% | 3 | 1.42% |
| Christopher Covington | 142 | 1.10% | 2 | 0.95% |
| Rabin Vincent | 129 | 1.00% | 2 | 0.95% |
| Ilpo Järvinen | 127 | 0.98% | 4 | 1.90% |
| Shreshtha Kumar Sahu | 118 | 0.91% | 2 | 0.95% |
| Rob Herring | 117 | 0.90% | 2 | 0.95% |
| Daniel R Thompson | 100 | 0.77% | 1 | 0.47% |
| Anton Vorontsov | 92 | 0.71% | 2 | 0.95% |
| Lukas Wunner | 92 | 0.71% | 6 | 2.84% |
| Linus Torvalds (pre-git) | 90 | 0.69% | 18 | 8.53% |
| Jun Nie | 87 | 0.67% | 2 | 0.95% |
| Tushar Behera | 86 | 0.66% | 2 | 0.95% |
| Alessandro Rubini | 82 | 0.63% | 4 | 1.90% |
| Jason Wessel | 77 | 0.59% | 2 | 0.95% |
| Leo (Hao) Chen | 72 | 0.56% | 1 | 0.47% |
| Jongsung Kim | 70 | 0.54% | 2 | 0.95% |
| Jon Medhurst (Tixy) | 70 | 0.54% | 3 | 1.42% |
| Shubhrajyoti Datta | 69 | 0.53% | 1 | 0.47% |
| Jorge Ramirez-Ortiz | 56 | 0.43% | 1 | 0.47% |
| delisun | 55 | 0.42% | 1 | 0.47% |
| Jiri Slaby | 52 | 0.40% | 5 | 2.37% |
| Thomas Gleixner | 34 | 0.26% | 1 | 0.47% |
| Guennadi Liakhovetski | 34 | 0.26% | 4 | 1.90% |
| Peter Zijlstra | 33 | 0.25% | 1 | 0.47% |
| Arnd Bergmann | 32 | 0.25% | 2 | 0.95% |
| Graeme Gregory | 30 | 0.23% | 1 | 0.47% |
| Jayachandran C | 29 | 0.22% | 1 | 0.47% |
| Rajanikanth H.V | 27 | 0.21% | 1 | 0.47% |
| Jingoo Han | 21 | 0.16% | 1 | 0.47% |
| Peter Hurley | 21 | 0.16% | 2 | 0.95% |
| Kees Cook | 19 | 0.15% | 1 | 0.47% |
| Qian Cai | 19 | 0.15% | 1 | 0.47% |
| Anders Roxell | 18 | 0.14% | 1 | 0.47% |
| Fabio Estevam | 16 | 0.12% | 1 | 0.47% |
| Ulf Hansson | 13 | 0.10% | 1 | 0.47% |
| Viresh Kumar | 13 | 0.10% | 1 | 0.47% |
| Al Viro | 12 | 0.09% | 1 | 0.47% |
| Ed Spiridonov | 12 | 0.09% | 1 | 0.47% |
| Dmitry Safonov | 11 | 0.08% | 1 | 0.47% |
| Kefeng Wang | 9 | 0.07% | 1 | 0.47% |
| Bing Fan | 8 | 0.06% | 1 | 0.47% |
| Jiamei Xie | 8 | 0.06% | 1 | 0.47% |
| David Woodhouse | 8 | 0.06% | 1 | 0.47% |
| Alan Cox | 7 | 0.05% | 3 | 1.42% |
| Krzysztof Kozlowski | 7 | 0.05% | 1 | 0.47% |
| Pierre Gondois | 6 | 0.05% | 1 | 0.47% |
| Linus Torvalds | 6 | 0.05% | 2 | 0.95% |
| Hongyu Xie | 5 | 0.04% | 1 | 0.47% |
| Julia Lawall | 5 | 0.04% | 2 | 0.95% |
| Vinod Koul | 4 | 0.03% | 1 | 0.47% |
| Alexander Sverdlin | 2 | 0.02% | 1 | 0.47% |
| Andrew Morton | 2 | 0.02% | 1 | 0.47% |
| Alex Bounine | 2 | 0.02% | 1 | 0.47% |
| Robin Murphy | 2 | 0.02% | 1 | 0.47% |
| Lucas De Marchi | 1 | 0.01% | 1 | 0.47% |
| Lee Jones | 1 | 0.01% | 1 | 0.47% |
| Vincent Sanders | 1 | 0.01% | 1 | 0.47% |
| Peter Ujfalusi | 1 | 0.01% | 1 | 0.47% |
| Arvind Yadav | 1 | 0.01% | 1 | 0.47% |
| Yinghai Lu | 1 | 0.01% | 1 | 0.47% |
| Uwe Kleine-König | 1 | 0.01% | 1 | 0.47% |
| Sudeep Holla | 1 | 0.01% | 1 | 0.47% |
| Vincent Whitchurch | 1 | 0.01% | 1 | 0.47% |
| Bhumika Goyal | 1 | 0.01% | 1 | 0.47% |
| Total | 12950 | 211 |
// SPDX-License-Identifier: GPL-2.0+ /* * Driver for AMBA serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * Copyright 1999 ARM Limited * Copyright (C) 2000 Deep Blue Solutions Ltd. * Copyright (C) 2010 ST-Ericsson SA * * This is a generic driver for ARM AMBA-type serial ports. They * have a lot of 16550-like features, but are not register compatible. * Note that although they do have CTS, DCD and DSR inputs, they do * not have an RI input, nor do they have DTR or RTS outputs. If * required, these have to be supplied via some other means (eg, GPIO) * and hooked into this driver. */ #include <linux/module.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/device.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/serial_core.h> #include <linux/serial.h> #include <linux/amba/bus.h> #include <linux/amba/serial.h> #include <linux/clk.h> #include <linux/slab.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/scatterlist.h> #include <linux/delay.h> #include <linux/types.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/pinctrl/consumer.h> #include <linux/sizes.h> #include <linux/io.h> #include <linux/acpi.h> #define UART_NR 14 #define SERIAL_AMBA_MAJOR 204 #define SERIAL_AMBA_MINOR 64 #define SERIAL_AMBA_NR UART_NR #define AMBA_ISR_PASS_LIMIT 256 #define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE) #define UART_DUMMY_DR_RX (1 << 16) enum { REG_DR, REG_ST_DMAWM, REG_ST_TIMEOUT, REG_FR, REG_LCRH_RX, REG_LCRH_TX, REG_IBRD, REG_FBRD, REG_CR, REG_IFLS, REG_IMSC, REG_RIS, REG_MIS, REG_ICR, REG_DMACR, REG_ST_XFCR, REG_ST_XON1, REG_ST_XON2, REG_ST_XOFF1, REG_ST_XOFF2, REG_ST_ITCR, REG_ST_ITIP, REG_ST_ABCR, REG_ST_ABIMSC, /* The size of the array - must be last */ REG_ARRAY_SIZE, }; static u16 pl011_std_offsets[REG_ARRAY_SIZE] = { [REG_DR] = UART01x_DR, [REG_FR] = UART01x_FR, [REG_LCRH_RX] = UART011_LCRH, [REG_LCRH_TX] = UART011_LCRH, [REG_IBRD] = UART011_IBRD, [REG_FBRD] = UART011_FBRD, [REG_CR] = UART011_CR, [REG_IFLS] = UART011_IFLS, [REG_IMSC] = UART011_IMSC, [REG_RIS] = UART011_RIS, [REG_MIS] = UART011_MIS, [REG_ICR] = UART011_ICR, [REG_DMACR] = UART011_DMACR, }; /* There is by now at least one vendor with differing details, so handle it */ struct vendor_data { const u16 *reg_offset; unsigned int ifls; unsigned int fr_busy; unsigned int fr_dsr; unsigned int fr_cts; unsigned int fr_ri; unsigned int inv_fr; bool access_32b; bool oversampling; bool dma_threshold; bool cts_event_workaround; bool always_enabled; bool fixed_options; unsigned int (*get_fifosize)(struct amba_device *dev); }; static unsigned int get_fifosize_arm(struct amba_device *dev) { return amba_rev(dev) < 3 ? 16 : 32; } static struct vendor_data vendor_arm = { .reg_offset = pl011_std_offsets, .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8, .fr_busy = UART01x_FR_BUSY, .fr_dsr = UART01x_FR_DSR, .fr_cts = UART01x_FR_CTS, .fr_ri = UART011_FR_RI, .oversampling = false, .dma_threshold = false, .cts_event_workaround = false, .always_enabled = false, .fixed_options = false, .get_fifosize = get_fifosize_arm, }; static const struct vendor_data vendor_sbsa = { .reg_offset = pl011_std_offsets, .fr_busy = UART01x_FR_BUSY, .fr_dsr = UART01x_FR_DSR, .fr_cts = UART01x_FR_CTS, .fr_ri = UART011_FR_RI, .access_32b = true, .oversampling = false, .dma_threshold = false, .cts_event_workaround = false, .always_enabled = true, .fixed_options = true, }; #ifdef CONFIG_ACPI_SPCR_TABLE static const struct vendor_data vendor_qdt_qdf2400_e44 = { .reg_offset = pl011_std_offsets, .fr_busy = UART011_FR_TXFE, .fr_dsr = UART01x_FR_DSR, .fr_cts = UART01x_FR_CTS, .fr_ri = UART011_FR_RI, .inv_fr = UART011_FR_TXFE, .access_32b = true, .oversampling = false, .dma_threshold = false, .cts_event_workaround = false, .always_enabled = true, .fixed_options = true, }; #endif static u16 pl011_st_offsets[REG_ARRAY_SIZE] = { [REG_DR] = UART01x_DR, [REG_ST_DMAWM] = ST_UART011_DMAWM, [REG_ST_TIMEOUT] = ST_UART011_TIMEOUT, [REG_FR] = UART01x_FR, [REG_LCRH_RX] = ST_UART011_LCRH_RX, [REG_LCRH_TX] = ST_UART011_LCRH_TX, [REG_IBRD] = UART011_IBRD, [REG_FBRD] = UART011_FBRD, [REG_CR] = UART011_CR, [REG_IFLS] = UART011_IFLS, [REG_IMSC] = UART011_IMSC, [REG_RIS] = UART011_RIS, [REG_MIS] = UART011_MIS, [REG_ICR] = UART011_ICR, [REG_DMACR] = UART011_DMACR, [REG_ST_XFCR] = ST_UART011_XFCR, [REG_ST_XON1] = ST_UART011_XON1, [REG_ST_XON2] = ST_UART011_XON2, [REG_ST_XOFF1] = ST_UART011_XOFF1, [REG_ST_XOFF2] = ST_UART011_XOFF2, [REG_ST_ITCR] = ST_UART011_ITCR, [REG_ST_ITIP] = ST_UART011_ITIP, [REG_ST_ABCR] = ST_UART011_ABCR, [REG_ST_ABIMSC] = ST_UART011_ABIMSC, }; static unsigned int get_fifosize_st(struct amba_device *dev) { return 64; } static struct vendor_data vendor_st = { .reg_offset = pl011_st_offsets, .ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF, .fr_busy = UART01x_FR_BUSY, .fr_dsr = UART01x_FR_DSR, .fr_cts = UART01x_FR_CTS, .fr_ri = UART011_FR_RI, .oversampling = true, .dma_threshold = true, .cts_event_workaround = true, .always_enabled = false, .fixed_options = false, .get_fifosize = get_fifosize_st, }; /* Deals with DMA transactions */ struct pl011_sgbuf { struct scatterlist sg; char *buf; }; struct pl011_dmarx_data { struct dma_chan *chan; struct completion complete; bool use_buf_b; struct pl011_sgbuf sgbuf_a; struct pl011_sgbuf sgbuf_b; dma_cookie_t cookie; bool running; struct timer_list timer; unsigned int last_residue; unsigned long last_jiffies; bool auto_poll_rate; unsigned int poll_rate; unsigned int poll_timeout; }; struct pl011_dmatx_data { struct dma_chan *chan; struct scatterlist sg; char *buf; bool queued; }; /* * We wrap our port structure around the generic uart_port. */ struct uart_amba_port { struct uart_port port; const u16 *reg_offset; struct clk *clk; const struct vendor_data *vendor; unsigned int dmacr; /* dma control reg */ unsigned int im; /* interrupt mask */ unsigned int old_status; unsigned int fifosize; /* vendor-specific */ unsigned int fixed_baud; /* vendor-set fixed baud rate */ char type[12]; bool rs485_tx_started; unsigned int rs485_tx_drain_interval; /* usecs */ #ifdef CONFIG_DMA_ENGINE /* DMA stuff */ bool using_tx_dma; bool using_rx_dma; struct pl011_dmarx_data dmarx; struct pl011_dmatx_data dmatx; bool dma_probed; #endif }; static unsigned int pl011_tx_empty(struct uart_port *port); static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap, unsigned int reg) { return uap->reg_offset[reg]; } static unsigned int pl011_read(const struct uart_amba_port *uap, unsigned int reg) { void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg); return (uap->port.iotype == UPIO_MEM32) ? readl_relaxed(addr) : readw_relaxed(addr); } static void pl011_write(unsigned int val, const struct uart_amba_port *uap, unsigned int reg) { void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg); if (uap->port.iotype == UPIO_MEM32) writel_relaxed(val, addr); else writew_relaxed(val, addr); } /* * Reads up to 256 characters from the FIFO or until it's empty and * inserts them into the TTY layer. Returns the number of characters * read from the FIFO. */ static int pl011_fifo_to_tty(struct uart_amba_port *uap) { unsigned int ch, flag, fifotaken; int sysrq; u16 status; for (fifotaken = 0; fifotaken != 256; fifotaken++) { status = pl011_read(uap, REG_FR); if (status & UART01x_FR_RXFE) break; /* Take chars from the FIFO and update status */ ch = pl011_read(uap, REG_DR) | UART_DUMMY_DR_RX; flag = TTY_NORMAL; uap->port.icount.rx++; if (unlikely(ch & UART_DR_ERROR)) { if (ch & UART011_DR_BE) { ch &= ~(UART011_DR_FE | UART011_DR_PE); uap->port.icount.brk++; if (uart_handle_break(&uap->port)) continue; } else if (ch & UART011_DR_PE) uap->port.icount.parity++; else if (ch & UART011_DR_FE) uap->port.icount.frame++; if (ch & UART011_DR_OE) uap->port.icount.overrun++; ch &= uap->port.read_status_mask; if (ch & UART011_DR_BE) flag = TTY_BREAK; else if (ch & UART011_DR_PE) flag = TTY_PARITY; else if (ch & UART011_DR_FE) flag = TTY_FRAME; } spin_unlock(&uap->port.lock); sysrq = uart_handle_sysrq_char(&uap->port, ch & 255); spin_lock(&uap->port.lock); if (!sysrq) uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); } return fifotaken; } /* * All the DMA operation mode stuff goes inside this ifdef. * This assumes that you have a generic DMA device interface, * no custom DMA interfaces are supported. */ #ifdef CONFIG_DMA_ENGINE #define PL011_DMA_BUFFER_SIZE PAGE_SIZE static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg, enum dma_data_direction dir) { dma_addr_t dma_addr; sg->buf = dma_alloc_coherent(chan->device->dev, PL011_DMA_BUFFER_SIZE, &dma_addr, GFP_KERNEL); if (!sg->buf) return -ENOMEM; sg_init_table(&sg->sg, 1); sg_set_page(&sg->sg, phys_to_page(dma_addr), PL011_DMA_BUFFER_SIZE, offset_in_page(dma_addr)); sg_dma_address(&sg->sg) = dma_addr; sg_dma_len(&sg->sg) = PL011_DMA_BUFFER_SIZE; return 0; } static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg, enum dma_data_direction dir) { if (sg->buf) { dma_free_coherent(chan->device->dev, PL011_DMA_BUFFER_SIZE, sg->buf, sg_dma_address(&sg->sg)); } } static void pl011_dma_probe(struct uart_amba_port *uap) { /* DMA is the sole user of the platform data right now */ struct amba_pl011_data *plat = dev_get_platdata(uap->port.dev); struct device *dev = uap->port.dev; struct dma_slave_config tx_conf = { .dst_addr = uap->port.mapbase + pl011_reg_to_offset(uap, REG_DR), .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, .direction = DMA_MEM_TO_DEV, .dst_maxburst = uap->fifosize >> 1, .device_fc = false, }; struct dma_chan *chan; dma_cap_mask_t mask; uap->dma_probed = true; chan = dma_request_chan(dev, "tx"); if (IS_ERR(chan)) { if (PTR_ERR(chan) == -EPROBE_DEFER) { uap->dma_probed = false; return; } /* We need platform data */ if (!plat || !plat->dma_filter) { dev_info(uap->port.dev, "no DMA platform data\n"); return; } /* Try to acquire a generic DMA engine slave TX channel */ dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); chan = dma_request_channel(mask, plat->dma_filter, plat->dma_tx_param); if (!chan) { dev_err(uap->port.dev, "no TX DMA channel!\n"); return; } } dmaengine_slave_config(chan, &tx_conf); uap->dmatx.chan = chan; dev_info(uap->port.dev, "DMA channel TX %s\n", dma_chan_name(uap->dmatx.chan)); /* Optionally make use of an RX channel as well */ chan = dma_request_slave_channel(dev, "rx"); if (!chan && plat && plat->dma_rx_param) { chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param); if (!chan) { dev_err(uap->port.dev, "no RX DMA channel!\n"); return; } } if (chan) { struct dma_slave_config rx_conf = { .src_addr = uap->port.mapbase + pl011_reg_to_offset(uap, REG_DR), .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, .direction = DMA_DEV_TO_MEM, .src_maxburst = uap->fifosize >> 2, .device_fc = false, }; struct dma_slave_caps caps; /* * Some DMA controllers provide information on their capabilities. * If the controller does, check for suitable residue processing * otherwise assime all is well. */ if (0 == dma_get_slave_caps(chan, &caps)) { if (caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) { dma_release_channel(chan); dev_info(uap->port.dev, "RX DMA disabled - no residue processing\n"); return; } } dmaengine_slave_config(chan, &rx_conf); uap->dmarx.chan = chan; uap->dmarx.auto_poll_rate = false; if (plat && plat->dma_rx_poll_enable) { /* Set poll rate if specified. */ if (plat->dma_rx_poll_rate) { uap->dmarx.auto_poll_rate = false; uap->dmarx.poll_rate = plat->dma_rx_poll_rate; } else { /* * 100 ms defaults to poll rate if not * specified. This will be adjusted with * the baud rate at set_termios. */ uap->dmarx.auto_poll_rate = true; uap->dmarx.poll_rate = 100; } /* 3 secs defaults poll_timeout if not specified. */ if (plat->dma_rx_poll_timeout) uap->dmarx.poll_timeout = plat->dma_rx_poll_timeout; else uap->dmarx.poll_timeout = 3000; } else if (!plat && dev->of_node) { uap->dmarx.auto_poll_rate = of_property_read_bool( dev->of_node, "auto-poll"); if (uap->dmarx.auto_poll_rate) { u32 x; if (0 == of_property_read_u32(dev->of_node, "poll-rate-ms", &x)) uap->dmarx.poll_rate = x; else uap->dmarx.poll_rate = 100; if (0 == of_property_read_u32(dev->of_node, "poll-timeout-ms", &x)) uap->dmarx.poll_timeout = x; else uap->dmarx.poll_timeout = 3000; } } dev_info(uap->port.dev, "DMA channel RX %s\n", dma_chan_name(uap->dmarx.chan)); } } static void pl011_dma_remove(struct uart_amba_port *uap) { if (uap->dmatx.chan) dma_release_channel(uap->dmatx.chan); if (uap->dmarx.chan) dma_release_channel(uap->dmarx.chan); } /* Forward declare these for the refill routine */ static int pl011_dma_tx_refill(struct uart_amba_port *uap); static void pl011_start_tx_pio(struct uart_amba_port *uap); /* * The current DMA TX buffer has been sent. * Try to queue up another DMA buffer. */ static void pl011_dma_tx_callback(void *data) { struct uart_amba_port *uap = data; struct pl011_dmatx_data *dmatx = &uap->dmatx; unsigned long flags; u16 dmacr; spin_lock_irqsave(&uap->port.lock, flags); if (uap->dmatx.queued) dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1, DMA_TO_DEVICE); dmacr = uap->dmacr; uap->dmacr = dmacr & ~UART011_TXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); /* * If TX DMA was disabled, it means that we've stopped the DMA for * some reason (eg, XOFF received, or we want to send an X-char.) * * Note: we need to be careful here of a potential race between DMA * and the rest of the driver - if the driver disables TX DMA while * a TX buffer completing, we must update the tx queued status to * get further refills (hence we check dmacr). */ if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) || uart_circ_empty(&uap->port.state->xmit)) { uap->dmatx.queued = false; spin_unlock_irqrestore(&uap->port.lock, flags); return; } if (pl011_dma_tx_refill(uap) <= 0) /* * We didn't queue a DMA buffer for some reason, but we * have data pending to be sent. Re-enable the TX IRQ. */ pl011_start_tx_pio(uap); spin_unlock_irqrestore(&uap->port.lock, flags); } /* * Try to refill the TX DMA buffer. * Locking: called with port lock held and IRQs disabled. * Returns: * 1 if we queued up a TX DMA buffer. * 0 if we didn't want to handle this by DMA * <0 on error */ static int pl011_dma_tx_refill(struct uart_amba_port *uap) { struct pl011_dmatx_data *dmatx = &uap->dmatx; struct dma_chan *chan = dmatx->chan; struct dma_device *dma_dev = chan->device; struct dma_async_tx_descriptor *desc; struct circ_buf *xmit = &uap->port.state->xmit; unsigned int count; /* * Try to avoid the overhead involved in using DMA if the * transaction fits in the first half of the FIFO, by using * the standard interrupt handling. This ensures that we * issue a uart_write_wakeup() at the appropriate time. */ count = uart_circ_chars_pending(xmit); if (count < (uap->fifosize >> 1)) { uap->dmatx.queued = false; return 0; } /* * Bodge: don't send the last character by DMA, as this * will prevent XON from notifying us to restart DMA. */ count -= 1; /* Else proceed to copy the TX chars to the DMA buffer and fire DMA */ if (count > PL011_DMA_BUFFER_SIZE) count = PL011_DMA_BUFFER_SIZE; if (xmit->tail < xmit->head) memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count); else { size_t first = UART_XMIT_SIZE - xmit->tail; size_t second; if (first > count) first = count; second = count - first; memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first); if (second) memcpy(&dmatx->buf[first], &xmit->buf[0], second); } dmatx->sg.length = count; if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) { uap->dmatx.queued = false; dev_dbg(uap->port.dev, "unable to map TX DMA\n"); return -EBUSY; } desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE); uap->dmatx.queued = false; /* * If DMA cannot be used right now, we complete this * transaction via IRQ and let the TTY layer retry. */ dev_dbg(uap->port.dev, "TX DMA busy\n"); return -EBUSY; } /* Some data to go along to the callback */ desc->callback = pl011_dma_tx_callback; desc->callback_param = uap; /* All errors should happen at prepare time */ dmaengine_submit(desc); /* Fire the DMA transaction */ dma_dev->device_issue_pending(chan); uap->dmacr |= UART011_TXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); uap->dmatx.queued = true; /* * Now we know that DMA will fire, so advance the ring buffer * with the stuff we just dispatched. */ uart_xmit_advance(&uap->port, count); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&uap->port); return 1; } /* * We received a transmit interrupt without a pending X-char but with * pending characters. * Locking: called with port lock held and IRQs disabled. * Returns: * false if we want to use PIO to transmit * true if we queued a DMA buffer */ static bool pl011_dma_tx_irq(struct uart_amba_port *uap) { if (!uap->using_tx_dma) return false; /* * If we already have a TX buffer queued, but received a * TX interrupt, it will be because we've just sent an X-char. * Ensure the TX DMA is enabled and the TX IRQ is disabled. */ if (uap->dmatx.queued) { uap->dmacr |= UART011_TXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); uap->im &= ~UART011_TXIM; pl011_write(uap->im, uap, REG_IMSC); return true; } /* * We don't have a TX buffer queued, so try to queue one. * If we successfully queued a buffer, mask the TX IRQ. */ if (pl011_dma_tx_refill(uap) > 0) { uap->im &= ~UART011_TXIM; pl011_write(uap->im, uap, REG_IMSC); return true; } return false; } /* * Stop the DMA transmit (eg, due to received XOFF). * Locking: called with port lock held and IRQs disabled. */ static inline void pl011_dma_tx_stop(struct uart_amba_port *uap) { if (uap->dmatx.queued) { uap->dmacr &= ~UART011_TXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); } } /* * Try to start a DMA transmit, or in the case of an XON/OFF * character queued for send, try to get that character out ASAP. * Locking: called with port lock held and IRQs disabled. * Returns: * false if we want the TX IRQ to be enabled * true if we have a buffer queued */ static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) { u16 dmacr; if (!uap->using_tx_dma) return false; if (!uap->port.x_char) { /* no X-char, try to push chars out in DMA mode */ bool ret = true; if (!uap->dmatx.queued) { if (pl011_dma_tx_refill(uap) > 0) { uap->im &= ~UART011_TXIM; pl011_write(uap->im, uap, REG_IMSC); } else ret = false; } else if (!(uap->dmacr & UART011_TXDMAE)) { uap->dmacr |= UART011_TXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); } return ret; } /* * We have an X-char to send. Disable DMA to prevent it loading * the TX fifo, and then see if we can stuff it into the FIFO. */ dmacr = uap->dmacr; uap->dmacr &= ~UART011_TXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); if (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) { /* * No space in the FIFO, so enable the transmit interrupt * so we know when there is space. Note that once we've * loaded the character, we should just re-enable DMA. */ return false; } pl011_write(uap->port.x_char, uap, REG_DR); uap->port.icount.tx++; uap->port.x_char = 0; /* Success - restore the DMA state */ uap->dmacr = dmacr; pl011_write(dmacr, uap, REG_DMACR); return true; } /* * Flush the transmit buffer. * Locking: called with port lock held and IRQs disabled. */ static void pl011_dma_flush_buffer(struct uart_port *port) __releases(&uap->port.lock) __acquires(&uap->port.lock) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); if (!uap->using_tx_dma) return; dmaengine_terminate_async(uap->dmatx.chan); if (uap->dmatx.queued) { dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, DMA_TO_DEVICE); uap->dmatx.queued = false; uap->dmacr &= ~UART011_TXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); } } static void pl011_dma_rx_callback(void *data); static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) { struct dma_chan *rxchan = uap->dmarx.chan; struct pl011_dmarx_data *dmarx = &uap->dmarx; struct dma_async_tx_descriptor *desc; struct pl011_sgbuf *sgbuf; if (!rxchan) return -EIO; /* Start the RX DMA job */ sgbuf = uap->dmarx.use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); /* * If the DMA engine is busy and cannot prepare a * channel, no big deal, the driver will fall back * to interrupt mode as a result of this error code. */ if (!desc) { uap->dmarx.running = false; dmaengine_terminate_all(rxchan); return -EBUSY; } /* Some data to go along to the callback */ desc->callback = pl011_dma_rx_callback; desc->callback_param = uap; dmarx->cookie = dmaengine_submit(desc); dma_async_issue_pending(rxchan); uap->dmacr |= UART011_RXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); uap->dmarx.running = true; uap->im &= ~UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); return 0; } /* * This is called when either the DMA job is complete, or * the FIFO timeout interrupt occurred. This must be called * with the port spinlock uap->port.lock held. */ static void pl011_dma_rx_chars(struct uart_amba_port *uap, u32 pending, bool use_buf_b, bool readfifo) { struct tty_port *port = &uap->port.state->port; struct pl011_sgbuf *sgbuf = use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; int dma_count = 0; u32 fifotaken = 0; /* only used for vdbg() */ struct pl011_dmarx_data *dmarx = &uap->dmarx; int dmataken = 0; if (uap->dmarx.poll_rate) { /* The data can be taken by polling */ dmataken = sgbuf->sg.length - dmarx->last_residue; /* Recalculate the pending size */ if (pending >= dmataken) pending -= dmataken; } /* Pick the remain data from the DMA */ if (pending) { /* * First take all chars in the DMA pipe, then look in the FIFO. * Note that tty_insert_flip_buf() tries to take as many chars * as it can. */ dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken, pending); uap->port.icount.rx += dma_count; if (dma_count < pending) dev_warn(uap->port.dev, "couldn't insert all characters (TTY is full?)\n"); } /* Reset the last_residue for Rx DMA poll */ if (uap->dmarx.poll_rate) dmarx->last_residue = sgbuf->sg.length; /* * Only continue with trying to read the FIFO if all DMA chars have * been taken first. */ if (dma_count == pending && readfifo) { /* Clear any error flags */ pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS, uap, REG_ICR); /* * If we read all the DMA'd characters, and we had an * incomplete buffer, that could be due to an rx error, or * maybe we just timed out. Read any pending chars and check * the error status. * * Error conditions will only occur in the FIFO, these will * trigger an immediate interrupt and stop the DMA job, so we * will always find the error in the FIFO, never in the DMA * buffer. */ fifotaken = pl011_fifo_to_tty(uap); } dev_vdbg(uap->port.dev, "Took %d chars from DMA buffer and %d chars from the FIFO\n", dma_count, fifotaken); tty_flip_buffer_push(port); } static void pl011_dma_rx_irq(struct uart_amba_port *uap) { struct pl011_dmarx_data *dmarx = &uap->dmarx; struct dma_chan *rxchan = dmarx->chan; struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? &dmarx->sgbuf_b : &dmarx->sgbuf_a; size_t pending; struct dma_tx_state state; enum dma_status dmastat; /* * Pause the transfer so we can trust the current counter, * do this before we pause the PL011 block, else we may * overflow the FIFO. */ if (dmaengine_pause(rxchan)) dev_err(uap->port.dev, "unable to pause DMA transfer\n"); dmastat = rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); if (dmastat != DMA_PAUSED) dev_err(uap->port.dev, "unable to pause DMA transfer\n"); /* Disable RX DMA - incoming data will wait in the FIFO */ uap->dmacr &= ~UART011_RXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); uap->dmarx.running = false; pending = sgbuf->sg.length - state.residue; BUG_ON(pending > PL011_DMA_BUFFER_SIZE); /* Then we terminate the transfer - we now know our residue */ dmaengine_terminate_all(rxchan); /* * This will take the chars we have so far and insert * into the framework. */ pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true); /* Switch buffer & re-trigger DMA job */ dmarx->use_buf_b = !dmarx->use_buf_b; if (pl011_dma_rx_trigger_dma(uap)) { dev_dbg(uap->port.dev, "could not retrigger RX DMA job " "fall back to interrupt mode\n"); uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); } } static void pl011_dma_rx_callback(void *data) { struct uart_amba_port *uap = data; struct pl011_dmarx_data *dmarx = &uap->dmarx; struct dma_chan *rxchan = dmarx->chan; bool lastbuf = dmarx->use_buf_b; struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? &dmarx->sgbuf_b : &dmarx->sgbuf_a; size_t pending; struct dma_tx_state state; int ret; /* * This completion interrupt occurs typically when the * RX buffer is totally stuffed but no timeout has yet * occurred. When that happens, we just want the RX * routine to flush out the secondary DMA buffer while * we immediately trigger the next DMA job. */ spin_lock_irq(&uap->port.lock); /* * Rx data can be taken by the UART interrupts during * the DMA irq handler. So we check the residue here. */ rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); pending = sgbuf->sg.length - state.residue; BUG_ON(pending > PL011_DMA_BUFFER_SIZE); /* Then we terminate the transfer - we now know our residue */ dmaengine_terminate_all(rxchan); uap->dmarx.running = false; dmarx->use_buf_b = !lastbuf; ret = pl011_dma_rx_trigger_dma(uap); pl011_dma_rx_chars(uap, pending, lastbuf, false); spin_unlock_irq(&uap->port.lock); /* * Do this check after we picked the DMA chars so we don't * get some IRQ immediately from RX. */ if (ret) { dev_dbg(uap->port.dev, "could not retrigger RX DMA job " "fall back to interrupt mode\n"); uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); } } /* * Stop accepting received characters, when we're shutting down or * suspending this port. * Locking: called with port lock held and IRQs disabled. */ static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) { if (!uap->using_rx_dma) return; /* FIXME. Just disable the DMA enable */ uap->dmacr &= ~UART011_RXDMAE; pl011_write(uap->dmacr, uap, REG_DMACR); } /* * Timer handler for Rx DMA polling. * Every polling, It checks the residue in the dma buffer and transfer * data to the tty. Also, last_residue is updated for the next polling. */ static void pl011_dma_rx_poll(struct timer_list *t) { struct uart_amba_port *uap = from_timer(uap, t, dmarx.timer); struct tty_port *port = &uap->port.state->port; struct pl011_dmarx_data *dmarx = &uap->dmarx; struct dma_chan *rxchan = uap->dmarx.chan; unsigned long flags; unsigned int dmataken = 0; unsigned int size = 0; struct pl011_sgbuf *sgbuf; int dma_count; struct dma_tx_state state; sgbuf = dmarx->use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); if (likely(state.residue < dmarx->last_residue)) { dmataken = sgbuf->sg.length - dmarx->last_residue; size = dmarx->last_residue - state.residue; dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken, size); if (dma_count == size) dmarx->last_residue = state.residue; dmarx->last_jiffies = jiffies; } tty_flip_buffer_push(port); /* * If no data is received in poll_timeout, the driver will fall back * to interrupt mode. We will retrigger DMA at the first interrupt. */ if (jiffies_to_msecs(jiffies - dmarx->last_jiffies) > uap->dmarx.poll_timeout) { spin_lock_irqsave(&uap->port.lock, flags); pl011_dma_rx_stop(uap); uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); spin_unlock_irqrestore(&uap->port.lock, flags); uap->dmarx.running = false; dmaengine_terminate_all(rxchan); del_timer(&uap->dmarx.timer); } else { mod_timer(&uap->dmarx.timer, jiffies + msecs_to_jiffies(uap->dmarx.poll_rate)); } } static void pl011_dma_startup(struct uart_amba_port *uap) { int ret; if (!uap->dma_probed) pl011_dma_probe(uap); if (!uap->dmatx.chan) return; uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA); if (!uap->dmatx.buf) { dev_err(uap->port.dev, "no memory for DMA TX buffer\n"); uap->port.fifosize = uap->fifosize; return; } sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE); /* The DMA buffer is now the FIFO the TTY subsystem can use */ uap->port.fifosize = PL011_DMA_BUFFER_SIZE; uap->using_tx_dma = true; if (!uap->dmarx.chan) goto skip_rx; /* Allocate and map DMA RX buffers */ ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE); if (ret) { dev_err(uap->port.dev, "failed to init DMA %s: %d\n", "RX buffer A", ret); goto skip_rx; } ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE); if (ret) { dev_err(uap->port.dev, "failed to init DMA %s: %d\n", "RX buffer B", ret); pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE); goto skip_rx; } uap->using_rx_dma = true; skip_rx: /* Turn on DMA error (RX/TX will be enabled on demand) */ uap->dmacr |= UART011_DMAONERR; pl011_write(uap->dmacr, uap, REG_DMACR); /* * ST Micro variants has some specific dma burst threshold * compensation. Set this to 16 bytes, so burst will only * be issued above/below 16 bytes. */ if (uap->vendor->dma_threshold) pl011_write(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16, uap, REG_ST_DMAWM); if (uap->using_rx_dma) { if (pl011_dma_rx_trigger_dma(uap)) dev_dbg(uap->port.dev, "could not trigger initial " "RX DMA job, fall back to interrupt mode\n"); if (uap->dmarx.poll_rate) { timer_setup(&uap->dmarx.timer, pl011_dma_rx_poll, 0); mod_timer(&uap->dmarx.timer, jiffies + msecs_to_jiffies(uap->dmarx.poll_rate)); uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE; uap->dmarx.last_jiffies = jiffies; } } } static void pl011_dma_shutdown(struct uart_amba_port *uap) { if (!(uap->using_tx_dma || uap->using_rx_dma)) return; /* Disable RX and TX DMA */ while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy) cpu_relax(); spin_lock_irq(&uap->port.lock); uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE); pl011_write(uap->dmacr, uap, REG_DMACR); spin_unlock_irq(&uap->port.lock); if (uap->using_tx_dma) { /* In theory, this should already be done by pl011_dma_flush_buffer */ dmaengine_terminate_all(uap->dmatx.chan); if (uap->dmatx.queued) { dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, DMA_TO_DEVICE); uap->dmatx.queued = false; } kfree(uap->dmatx.buf); uap->using_tx_dma = false; } if (uap->using_rx_dma) { dmaengine_terminate_all(uap->dmarx.chan); /* Clean up the RX DMA */ pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE); pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE); if (uap->dmarx.poll_rate) del_timer_sync(&uap->dmarx.timer); uap->using_rx_dma = false; } } static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) { return uap->using_rx_dma; } static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) { return uap->using_rx_dma && uap->dmarx.running; } #else /* Blank functions if the DMA engine is not available */ static inline void pl011_dma_remove(struct uart_amba_port *uap) { } static inline void pl011_dma_startup(struct uart_amba_port *uap) { } static inline void pl011_dma_shutdown(struct uart_amba_port *uap) { } static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap) { return false; } static inline void pl011_dma_tx_stop(struct uart_amba_port *uap) { } static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) { return false; } static inline void pl011_dma_rx_irq(struct uart_amba_port *uap) { } static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) { } static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) { return -EIO; } static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) { return false; } static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) { return false; } #define pl011_dma_flush_buffer NULL #endif static void pl011_rs485_tx_stop(struct uart_amba_port *uap) { /* * To be on the safe side only time out after twice as many iterations * as fifo size. */ const int MAX_TX_DRAIN_ITERS = uap->port.fifosize * 2; struct uart_port *port = &uap->port; int i = 0; u32 cr; /* Wait until hardware tx queue is empty */ while (!pl011_tx_empty(port)) { if (i > MAX_TX_DRAIN_ITERS) { dev_warn(port->dev, "timeout while draining hardware tx queue\n"); break; } udelay(uap->rs485_tx_drain_interval); i++; } if (port->rs485.delay_rts_after_send) mdelay(port->rs485.delay_rts_after_send); cr = pl011_read(uap, REG_CR); if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) cr &= ~UART011_CR_RTS; else cr |= UART011_CR_RTS; /* Disable the transmitter and reenable the transceiver */ cr &= ~UART011_CR_TXE; cr |= UART011_CR_RXE; pl011_write(cr, uap, REG_CR); uap->rs485_tx_started = false; } static void pl011_stop_tx(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); uap->im &= ~UART011_TXIM; pl011_write(uap->im, uap, REG_IMSC); pl011_dma_tx_stop(uap); if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started) pl011_rs485_tx_stop(uap); } static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq); /* Start TX with programmed I/O only (no DMA) */ static void pl011_start_tx_pio(struct uart_amba_port *uap) { if (pl011_tx_chars(uap, false)) { uap->im |= UART011_TXIM; pl011_write(uap->im, uap, REG_IMSC); } } static void pl011_start_tx(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); if (!pl011_dma_tx_start(uap)) pl011_start_tx_pio(uap); } static void pl011_stop_rx(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM| UART011_PEIM|UART011_BEIM|UART011_OEIM); pl011_write(uap->im, uap, REG_IMSC); pl011_dma_rx_stop(uap); } static void pl011_throttle_rx(struct uart_port *port) { unsigned long flags; spin_lock_irqsave(&port->lock, flags); pl011_stop_rx(port); spin_unlock_irqrestore(&port->lock, flags); } static void pl011_enable_ms(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM; pl011_write(uap->im, uap, REG_IMSC); } static void pl011_rx_chars(struct uart_amba_port *uap) __releases(&uap->port.lock) __acquires(&uap->port.lock) { pl011_fifo_to_tty(uap); spin_unlock(&uap->port.lock); tty_flip_buffer_push(&uap->port.state->port); /* * If we were temporarily out of DMA mode for a while, * attempt to switch back to DMA mode again. */ if (pl011_dma_rx_available(uap)) { if (pl011_dma_rx_trigger_dma(uap)) { dev_dbg(uap->port.dev, "could not trigger RX DMA job " "fall back to interrupt mode again\n"); uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); } else { #ifdef CONFIG_DMA_ENGINE /* Start Rx DMA poll */ if (uap->dmarx.poll_rate) { uap->dmarx.last_jiffies = jiffies; uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE; mod_timer(&uap->dmarx.timer, jiffies + msecs_to_jiffies(uap->dmarx.poll_rate)); } #endif } } spin_lock(&uap->port.lock); } static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c, bool from_irq) { if (unlikely(!from_irq) && pl011_read(uap, REG_FR) & UART01x_FR_TXFF) return false; /* unable to transmit character */ pl011_write(c, uap, REG_DR); uap->port.icount.tx++; return true; } static void pl011_rs485_tx_start(struct uart_amba_port *uap) { struct uart_port *port = &uap->port; u32 cr; /* Enable transmitter */ cr = pl011_read(uap, REG_CR); cr |= UART011_CR_TXE; /* Disable receiver if half-duplex */ if (!(port->rs485.flags & SER_RS485_RX_DURING_TX)) cr &= ~UART011_CR_RXE; if (port->rs485.flags & SER_RS485_RTS_ON_SEND) cr &= ~UART011_CR_RTS; else cr |= UART011_CR_RTS; pl011_write(cr, uap, REG_CR); if (port->rs485.delay_rts_before_send) mdelay(port->rs485.delay_rts_before_send); uap->rs485_tx_started = true; } /* Returns true if tx interrupts have to be (kept) enabled */ static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq) { struct circ_buf *xmit = &uap->port.state->xmit; int count = uap->fifosize >> 1; if ((uap->port.rs485.flags & SER_RS485_ENABLED) && !uap->rs485_tx_started) pl011_rs485_tx_start(uap); if (uap->port.x_char) { if (!pl011_tx_char(uap, uap->port.x_char, from_irq)) return true; uap->port.x_char = 0; --count; } if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) { pl011_stop_tx(&uap->port); return false; } /* If we are using DMA mode, try to send some characters. */ if (pl011_dma_tx_irq(uap)) return true; do { if (likely(from_irq) && count-- == 0) break; if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq)) break; xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); } while (!uart_circ_empty(xmit)); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&uap->port); if (uart_circ_empty(xmit)) { pl011_stop_tx(&uap->port); return false; } return true; } static void pl011_modem_status(struct uart_amba_port *uap) { unsigned int status, delta; status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY; delta = status ^ uap->old_status; uap->old_status = status; if (!delta) return; if (delta & UART01x_FR_DCD) uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD); if (delta & uap->vendor->fr_dsr) uap->port.icount.dsr++; if (delta & uap->vendor->fr_cts) uart_handle_cts_change(&uap->port, status & uap->vendor->fr_cts); wake_up_interruptible(&uap->port.state->port.delta_msr_wait); } static void check_apply_cts_event_workaround(struct uart_amba_port *uap) { if (!uap->vendor->cts_event_workaround) return; /* workaround to make sure that all bits are unlocked.. */ pl011_write(0x00, uap, REG_ICR); /* * WA: introduce 26ns(1 uart clk) delay before W1C; * single apb access will incur 2 pclk(133.12Mhz) delay, * so add 2 dummy reads */ pl011_read(uap, REG_ICR); pl011_read(uap, REG_ICR); } static irqreturn_t pl011_int(int irq, void *dev_id) { struct uart_amba_port *uap = dev_id; unsigned long flags; unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; int handled = 0; spin_lock_irqsave(&uap->port.lock, flags); status = pl011_read(uap, REG_RIS) & uap->im; if (status) { do { check_apply_cts_event_workaround(uap); pl011_write(status & ~(UART011_TXIS|UART011_RTIS| UART011_RXIS), uap, REG_ICR); if (status & (UART011_RTIS|UART011_RXIS)) { if (pl011_dma_rx_running(uap)) pl011_dma_rx_irq(uap); else pl011_rx_chars(uap); } if (status & (UART011_DSRMIS|UART011_DCDMIS| UART011_CTSMIS|UART011_RIMIS)) pl011_modem_status(uap); if (status & UART011_TXIS) pl011_tx_chars(uap, true); if (pass_counter-- == 0) break; status = pl011_read(uap, REG_RIS) & uap->im; } while (status != 0); handled = 1; } spin_unlock_irqrestore(&uap->port.lock, flags); return IRQ_RETVAL(handled); } static unsigned int pl011_tx_empty(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); /* Allow feature register bits to be inverted to work around errata */ unsigned int status = pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr; return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT; } static unsigned int pl011_get_mctrl(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned int result = 0; unsigned int status = pl011_read(uap, REG_FR); #define TIOCMBIT(uartbit, tiocmbit) \ if (status & uartbit) \ result |= tiocmbit TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR); TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR); TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS); TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG); #undef TIOCMBIT return result; } static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned int cr; cr = pl011_read(uap, REG_CR); #define TIOCMBIT(tiocmbit, uartbit) \ if (mctrl & tiocmbit) \ cr |= uartbit; \ else \ cr &= ~uartbit TIOCMBIT(TIOCM_RTS, UART011_CR_RTS); TIOCMBIT(TIOCM_DTR, UART011_CR_DTR); TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1); TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2); TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE); if (port->status & UPSTAT_AUTORTS) { /* We need to disable auto-RTS if we want to turn RTS off */ TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN); } #undef TIOCMBIT pl011_write(cr, uap, REG_CR); } static void pl011_break_ctl(struct uart_port *port, int break_state) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned long flags; unsigned int lcr_h; spin_lock_irqsave(&uap->port.lock, flags); lcr_h = pl011_read(uap, REG_LCRH_TX); if (break_state == -1) lcr_h |= UART01x_LCRH_BRK; else lcr_h &= ~UART01x_LCRH_BRK; pl011_write(lcr_h, uap, REG_LCRH_TX); spin_unlock_irqrestore(&uap->port.lock, flags); } #ifdef CONFIG_CONSOLE_POLL static void pl011_quiesce_irqs(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); pl011_write(pl011_read(uap, REG_MIS), uap, REG_ICR); /* * There is no way to clear TXIM as this is "ready to transmit IRQ", so * we simply mask it. start_tx() will unmask it. * * Note we can race with start_tx(), and if the race happens, the * polling user might get another interrupt just after we clear it. * But it should be OK and can happen even w/o the race, e.g. * controller immediately got some new data and raised the IRQ. * * And whoever uses polling routines assumes that it manages the device * (including tx queue), so we're also fine with start_tx()'s caller * side. */ pl011_write(pl011_read(uap, REG_IMSC) & ~UART011_TXIM, uap, REG_IMSC); } static int pl011_get_poll_char(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned int status; /* * The caller might need IRQs lowered, e.g. if used with KDB NMI * debugger. */ pl011_quiesce_irqs(port); status = pl011_read(uap, REG_FR); if (status & UART01x_FR_RXFE) return NO_POLL_CHAR; return pl011_read(uap, REG_DR); } static void pl011_put_poll_char(struct uart_port *port, unsigned char ch) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) cpu_relax(); pl011_write(ch, uap, REG_DR); } #endif /* CONFIG_CONSOLE_POLL */ static int pl011_hwinit(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); int retval; /* Optionaly enable pins to be muxed in and configured */ pinctrl_pm_select_default_state(port->dev); /* * Try to enable the clock producer. */ retval = clk_prepare_enable(uap->clk); if (retval) return retval; uap->port.uartclk = clk_get_rate(uap->clk); /* Clear pending error and receive interrupts */ pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS | UART011_RTIS | UART011_RXIS, uap, REG_ICR); /* * Save interrupts enable mask, and enable RX interrupts in case if * the interrupt is used for NMI entry. */ uap->im = pl011_read(uap, REG_IMSC); pl011_write(UART011_RTIM | UART011_RXIM, uap, REG_IMSC); if (dev_get_platdata(uap->port.dev)) { struct amba_pl011_data *plat; plat = dev_get_platdata(uap->port.dev); if (plat->init) plat->init(); } return 0; } static bool pl011_split_lcrh(const struct uart_amba_port *uap) { return pl011_reg_to_offset(uap, REG_LCRH_RX) != pl011_reg_to_offset(uap, REG_LCRH_TX); } static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h) { pl011_write(lcr_h, uap, REG_LCRH_RX); if (pl011_split_lcrh(uap)) { int i; /* * Wait 10 PCLKs before writing LCRH_TX register, * to get this delay write read only register 10 times */ for (i = 0; i < 10; ++i) pl011_write(0xff, uap, REG_MIS); pl011_write(lcr_h, uap, REG_LCRH_TX); } } static int pl011_allocate_irq(struct uart_amba_port *uap) { pl011_write(uap->im, uap, REG_IMSC); return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap); } /* * Enable interrupts, only timeouts when using DMA * if initial RX DMA job failed, start in interrupt mode * as well. */ static void pl011_enable_interrupts(struct uart_amba_port *uap) { unsigned long flags; unsigned int i; spin_lock_irqsave(&uap->port.lock, flags); /* Clear out any spuriously appearing RX interrupts */ pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR); /* * RXIS is asserted only when the RX FIFO transitions from below * to above the trigger threshold. If the RX FIFO is already * full to the threshold this can't happen and RXIS will now be * stuck off. Drain the RX FIFO explicitly to fix this: */ for (i = 0; i < uap->fifosize * 2; ++i) { if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE) break; pl011_read(uap, REG_DR); } uap->im = UART011_RTIM; if (!pl011_dma_rx_running(uap)) uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); spin_unlock_irqrestore(&uap->port.lock, flags); } static void pl011_unthrottle_rx(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned long flags; spin_lock_irqsave(&uap->port.lock, flags); uap->im = UART011_RTIM; if (!pl011_dma_rx_running(uap)) uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); spin_unlock_irqrestore(&uap->port.lock, flags); } static int pl011_startup(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned int cr; int retval; retval = pl011_hwinit(port); if (retval) goto clk_dis; retval = pl011_allocate_irq(uap); if (retval) goto clk_dis; pl011_write(uap->vendor->ifls, uap, REG_IFLS); spin_lock_irq(&uap->port.lock); cr = pl011_read(uap, REG_CR); cr &= UART011_CR_RTS | UART011_CR_DTR; cr |= UART01x_CR_UARTEN | UART011_CR_RXE; if (!(port->rs485.flags & SER_RS485_ENABLED)) cr |= UART011_CR_TXE; pl011_write(cr, uap, REG_CR); spin_unlock_irq(&uap->port.lock); /* * initialise the old status of the modem signals */ uap->old_status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY; /* Startup DMA */ pl011_dma_startup(uap); pl011_enable_interrupts(uap); return 0; clk_dis: clk_disable_unprepare(uap->clk); return retval; } static int sbsa_uart_startup(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); int retval; retval = pl011_hwinit(port); if (retval) return retval; retval = pl011_allocate_irq(uap); if (retval) return retval; /* The SBSA UART does not support any modem status lines. */ uap->old_status = 0; pl011_enable_interrupts(uap); return 0; } static void pl011_shutdown_channel(struct uart_amba_port *uap, unsigned int lcrh) { unsigned long val; val = pl011_read(uap, lcrh); val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN); pl011_write(val, uap, lcrh); } /* * disable the port. It should not disable RTS and DTR. * Also RTS and DTR state should be preserved to restore * it during startup(). */ static void pl011_disable_uart(struct uart_amba_port *uap) { unsigned int cr; uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); spin_lock_irq(&uap->port.lock); cr = pl011_read(uap, REG_CR); cr &= UART011_CR_RTS | UART011_CR_DTR; cr |= UART01x_CR_UARTEN | UART011_CR_TXE; pl011_write(cr, uap, REG_CR); spin_unlock_irq(&uap->port.lock); /* * disable break condition and fifos */ pl011_shutdown_channel(uap, REG_LCRH_RX); if (pl011_split_lcrh(uap)) pl011_shutdown_channel(uap, REG_LCRH_TX); } static void pl011_disable_interrupts(struct uart_amba_port *uap) { spin_lock_irq(&uap->port.lock); /* mask all interrupts and clear all pending ones */ uap->im = 0; pl011_write(uap->im, uap, REG_IMSC); pl011_write(0xffff, uap, REG_ICR); spin_unlock_irq(&uap->port.lock); } static void pl011_shutdown(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); pl011_disable_interrupts(uap); pl011_dma_shutdown(uap); if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started) pl011_rs485_tx_stop(uap); free_irq(uap->port.irq, uap); pl011_disable_uart(uap); /* * Shut down the clock producer */ clk_disable_unprepare(uap->clk); /* Optionally let pins go into sleep states */ pinctrl_pm_select_sleep_state(port->dev); if (dev_get_platdata(uap->port.dev)) { struct amba_pl011_data *plat; plat = dev_get_platdata(uap->port.dev); if (plat->exit) plat->exit(); } if (uap->port.ops->flush_buffer) uap->port.ops->flush_buffer(port); } static void sbsa_uart_shutdown(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); pl011_disable_interrupts(uap); free_irq(uap->port.irq, uap); if (uap->port.ops->flush_buffer) uap->port.ops->flush_buffer(port); } static void pl011_setup_status_masks(struct uart_port *port, struct ktermios *termios) { port->read_status_mask = UART011_DR_OE | 255; if (termios->c_iflag & INPCK) port->read_status_mask |= UART011_DR_FE | UART011_DR_PE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= UART011_DR_BE; /* * Characters to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE; if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= UART011_DR_BE; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= UART011_DR_OE; } /* * Ignore all characters if CREAD is not set. */ if ((termios->c_cflag & CREAD) == 0) port->ignore_status_mask |= UART_DUMMY_DR_RX; } static void pl011_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned int lcr_h, old_cr; unsigned long flags; unsigned int baud, quot, clkdiv; unsigned int bits; if (uap->vendor->oversampling) clkdiv = 8; else clkdiv = 16; /* * Ask the core to calculate the divisor for us. */ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / clkdiv); #ifdef CONFIG_DMA_ENGINE /* * Adjust RX DMA polling rate with baud rate if not specified. */ if (uap->dmarx.auto_poll_rate) uap->dmarx.poll_rate = DIV_ROUND_UP(10000000, baud); #endif if (baud > port->uartclk/16) quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud); else quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud); switch (termios->c_cflag & CSIZE) { case CS5: lcr_h = UART01x_LCRH_WLEN_5; break; case CS6: lcr_h = UART01x_LCRH_WLEN_6; break; case CS7: lcr_h = UART01x_LCRH_WLEN_7; break; default: // CS8 lcr_h = UART01x_LCRH_WLEN_8; break; } if (termios->c_cflag & CSTOPB) lcr_h |= UART01x_LCRH_STP2; if (termios->c_cflag & PARENB) { lcr_h |= UART01x_LCRH_PEN; if (!(termios->c_cflag & PARODD)) lcr_h |= UART01x_LCRH_EPS; if (termios->c_cflag & CMSPAR) lcr_h |= UART011_LCRH_SPS; } if (uap->fifosize > 1) lcr_h |= UART01x_LCRH_FEN; bits = tty_get_frame_size(termios->c_cflag); spin_lock_irqsave(&port->lock, flags); /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); /* * Calculate the approximated time it takes to transmit one character * with the given baud rate. We use this as the poll interval when we * wait for the tx queue to empty. */ uap->rs485_tx_drain_interval = DIV_ROUND_UP(bits * 1000 * 1000, baud); pl011_setup_status_masks(port, termios); if (UART_ENABLE_MS(port, termios->c_cflag)) pl011_enable_ms(port); if (port->rs485.flags & SER_RS485_ENABLED) termios->c_cflag &= ~CRTSCTS; old_cr = pl011_read(uap, REG_CR); if (termios->c_cflag & CRTSCTS) { if (old_cr & UART011_CR_RTS) old_cr |= UART011_CR_RTSEN; old_cr |= UART011_CR_CTSEN; port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; } else { old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN); port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); } if (uap->vendor->oversampling) { if (baud > port->uartclk / 16) old_cr |= ST_UART011_CR_OVSFACT; else old_cr &= ~ST_UART011_CR_OVSFACT; } /* * Workaround for the ST Micro oversampling variants to * increase the bitrate slightly, by lowering the divisor, * to avoid delayed sampling of start bit at high speeds, * else we see data corruption. */ if (uap->vendor->oversampling) { if ((baud >= 3000000) && (baud < 3250000) && (quot > 1)) quot -= 1; else if ((baud > 3250000) && (quot > 2)) quot -= 2; } /* Set baud rate */ pl011_write(quot & 0x3f, uap, REG_FBRD); pl011_write(quot >> 6, uap, REG_IBRD); /* * ----------v----------v----------v----------v----- * NOTE: REG_LCRH_TX and REG_LCRH_RX MUST BE WRITTEN AFTER * REG_FBRD & REG_IBRD. * ----------^----------^----------^----------^----- */ pl011_write_lcr_h(uap, lcr_h); /* * Receive was disabled by pl011_disable_uart during shutdown. * Need to reenable receive if you need to use a tty_driver * returns from tty_find_polling_driver() after a port shutdown. */ old_cr |= UART011_CR_RXE; pl011_write(old_cr, uap, REG_CR); spin_unlock_irqrestore(&port->lock, flags); } static void sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned long flags; tty_termios_encode_baud_rate(termios, uap->fixed_baud, uap->fixed_baud); /* The SBSA UART only supports 8n1 without hardware flow control. */ termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD); termios->c_cflag &= ~(CMSPAR | CRTSCTS); termios->c_cflag |= CS8 | CLOCAL; spin_lock_irqsave(&port->lock, flags); uart_update_timeout(port, CS8, uap->fixed_baud); pl011_setup_status_masks(port, termios); spin_unlock_irqrestore(&port->lock, flags); } static const char *pl011_type(struct uart_port *port) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); return uap->port.type == PORT_AMBA ? uap->type : NULL; } /* * Configure/autoconfigure the port. */ static void pl011_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) port->type = PORT_AMBA; } /* * verify the new serial_struct (for TIOCSSERIAL). */ static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA) ret = -EINVAL; if (ser->irq < 0 || ser->irq >= nr_irqs) ret = -EINVAL; if (ser->baud_base < 9600) ret = -EINVAL; if (port->mapbase != (unsigned long) ser->iomem_base) ret = -EINVAL; return ret; } static int pl011_rs485_config(struct uart_port *port, struct ktermios *termios, struct serial_rs485 *rs485) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); if (port->rs485.flags & SER_RS485_ENABLED) pl011_rs485_tx_stop(uap); /* Make sure auto RTS is disabled */ if (rs485->flags & SER_RS485_ENABLED) { u32 cr = pl011_read(uap, REG_CR); cr &= ~UART011_CR_RTSEN; pl011_write(cr, uap, REG_CR); port->status &= ~UPSTAT_AUTORTS; } return 0; } static const struct uart_ops amba_pl011_pops = { .tx_empty = pl011_tx_empty, .set_mctrl = pl011_set_mctrl, .get_mctrl = pl011_get_mctrl, .stop_tx = pl011_stop_tx, .start_tx = pl011_start_tx, .stop_rx = pl011_stop_rx, .throttle = pl011_throttle_rx, .unthrottle = pl011_unthrottle_rx, .enable_ms = pl011_enable_ms, .break_ctl = pl011_break_ctl, .startup = pl011_startup, .shutdown = pl011_shutdown, .flush_buffer = pl011_dma_flush_buffer, .set_termios = pl011_set_termios, .type = pl011_type, .config_port = pl011_config_port, .verify_port = pl011_verify_port, #ifdef CONFIG_CONSOLE_POLL .poll_init = pl011_hwinit, .poll_get_char = pl011_get_poll_char, .poll_put_char = pl011_put_poll_char, #endif }; static void sbsa_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { } static unsigned int sbsa_uart_get_mctrl(struct uart_port *port) { return 0; } static const struct uart_ops sbsa_uart_pops = { .tx_empty = pl011_tx_empty, .set_mctrl = sbsa_uart_set_mctrl, .get_mctrl = sbsa_uart_get_mctrl, .stop_tx = pl011_stop_tx, .start_tx = pl011_start_tx, .stop_rx = pl011_stop_rx, .startup = sbsa_uart_startup, .shutdown = sbsa_uart_shutdown, .set_termios = sbsa_uart_set_termios, .type = pl011_type, .config_port = pl011_config_port, .verify_port = pl011_verify_port, #ifdef CONFIG_CONSOLE_POLL .poll_init = pl011_hwinit, .poll_get_char = pl011_get_poll_char, .poll_put_char = pl011_put_poll_char, #endif }; static struct uart_amba_port *amba_ports[UART_NR]; #ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE static void pl011_console_putchar(struct uart_port *port, unsigned char ch) { struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) cpu_relax(); pl011_write(ch, uap, REG_DR); } static void pl011_console_write(struct console *co, const char *s, unsigned int count) { struct uart_amba_port *uap = amba_ports[co->index]; unsigned int old_cr = 0, new_cr; unsigned long flags; int locked = 1; clk_enable(uap->clk); local_irq_save(flags); if (uap->port.sysrq) locked = 0; else if (oops_in_progress) locked = spin_trylock(&uap->port.lock); else spin_lock(&uap->port.lock); /* * First save the CR then disable the interrupts */ if (!uap->vendor->always_enabled) { old_cr = pl011_read(uap, REG_CR); new_cr = old_cr & ~UART011_CR_CTSEN; new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE; pl011_write(new_cr, uap, REG_CR); } uart_console_write(&uap->port, s, count, pl011_console_putchar); /* * Finally, wait for transmitter to become empty and restore the * TCR. Allow feature register bits to be inverted to work around * errata. */ while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr) & uap->vendor->fr_busy) cpu_relax(); if (!uap->vendor->always_enabled) pl011_write(old_cr, uap, REG_CR); if (locked) spin_unlock(&uap->port.lock); local_irq_restore(flags); clk_disable(uap->clk); } static void pl011_console_get_options(struct uart_amba_port *uap, int *baud, int *parity, int *bits) { if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) { unsigned int lcr_h, ibrd, fbrd; lcr_h = pl011_read(uap, REG_LCRH_TX); *parity = 'n'; if (lcr_h & UART01x_LCRH_PEN) { if (lcr_h & UART01x_LCRH_EPS) *parity = 'e'; else *parity = 'o'; } if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7) *bits = 7; else *bits = 8; ibrd = pl011_read(uap, REG_IBRD); fbrd = pl011_read(uap, REG_FBRD); *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd); if (uap->vendor->oversampling) { if (pl011_read(uap, REG_CR) & ST_UART011_CR_OVSFACT) *baud *= 2; } } } static int pl011_console_setup(struct console *co, char *options) { struct uart_amba_port *uap; int baud = 38400; int bits = 8; int parity = 'n'; int flow = 'n'; int ret; /* * Check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ if (co->index >= UART_NR) co->index = 0; uap = amba_ports[co->index]; if (!uap) return -ENODEV; /* Allow pins to be muxed in and configured */ pinctrl_pm_select_default_state(uap->port.dev); ret = clk_prepare(uap->clk); if (ret) return ret; if (dev_get_platdata(uap->port.dev)) { struct amba_pl011_data *plat; plat = dev_get_platdata(uap->port.dev); if (plat->init) plat->init(); } uap->port.uartclk = clk_get_rate(uap->clk); if (uap->vendor->fixed_options) { baud = uap->fixed_baud; } else { if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else pl011_console_get_options(uap, &baud, &parity, &bits); } return uart_set_options(&uap->port, co, baud, parity, bits, flow); } /** * pl011_console_match - non-standard console matching * @co: registering console * @name: name from console command line * @idx: index from console command line * @options: ptr to option string from console command line * * Only attempts to match console command lines of the form: * console=pl011,mmio|mmio32,<addr>[,<options>] * console=pl011,0x<addr>[,<options>] * This form is used to register an initial earlycon boot console and * replace it with the amba_console at pl011 driver init. * * Performs console setup for a match (as required by interface) * If no <options> are specified, then assume the h/w is already setup. * * Returns 0 if console matches; otherwise non-zero to use default matching */ static int pl011_console_match(struct console *co, char *name, int idx, char *options) { unsigned char iotype; resource_size_t addr; int i; /* * Systems affected by the Qualcomm Technologies QDF2400 E44 erratum * have a distinct console name, so make sure we check for that. * The actual implementation of the erratum occurs in the probe * function. */ if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0)) return -ENODEV; if (uart_parse_earlycon(options, &iotype, &addr, &options)) return -ENODEV; if (iotype != UPIO_MEM && iotype != UPIO_MEM32) return -ENODEV; /* try to match the port specified on the command line */ for (i = 0; i < ARRAY_SIZE(amba_ports); i++) { struct uart_port *port; if (!amba_ports[i]) continue; port = &amba_ports[i]->port; if (port->mapbase != addr) continue; co->index = i; port->cons = co; return pl011_console_setup(co, options); } return -ENODEV; } static struct uart_driver amba_reg; static struct console amba_console = { .name = "ttyAMA", .write = pl011_console_write, .device = uart_console_device, .setup = pl011_console_setup, .match = pl011_console_match, .flags = CON_PRINTBUFFER | CON_ANYTIME, .index = -1, .data = &amba_reg, }; #define AMBA_CONSOLE (&amba_console) static void qdf2400_e44_putc(struct uart_port *port, unsigned char c) { while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF) cpu_relax(); writel(c, port->membase + UART01x_DR); while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE)) cpu_relax(); } static void qdf2400_e44_early_write(struct console *con, const char *s, unsigned n) { struct earlycon_device *dev = con->data; uart_console_write(&dev->port, s, n, qdf2400_e44_putc); } static void pl011_putc(struct uart_port *port, unsigned char c) { while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF) cpu_relax(); if (port->iotype == UPIO_MEM32) writel(c, port->membase + UART01x_DR); else writeb(c, port->membase + UART01x_DR); while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY) cpu_relax(); } static void pl011_early_write(struct console *con, const char *s, unsigned n) { struct earlycon_device *dev = con->data; uart_console_write(&dev->port, s, n, pl011_putc); } #ifdef CONFIG_CONSOLE_POLL static int pl011_getc(struct uart_port *port) { if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE) return NO_POLL_CHAR; if (port->iotype == UPIO_MEM32) return readl(port->membase + UART01x_DR); else return readb(port->membase + UART01x_DR); } static int pl011_early_read(struct console *con, char *s, unsigned int n) { struct earlycon_device *dev = con->data; int ch, num_read = 0; while (num_read < n) { ch = pl011_getc(&dev->port); if (ch == NO_POLL_CHAR) break; s[num_read++] = ch; } return num_read; } #else #define pl011_early_read NULL #endif /* * On non-ACPI systems, earlycon is enabled by specifying * "earlycon=pl011,<address>" on the kernel command line. * * On ACPI ARM64 systems, an "early" console is enabled via the SPCR table, * by specifying only "earlycon" on the command line. Because it requires * SPCR, the console starts after ACPI is parsed, which is later than a * traditional early console. * * To get the traditional early console that starts before ACPI is parsed, * specify the full "earlycon=pl011,<address>" option. */ static int __init pl011_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; device->con->write = pl011_early_write; device->con->read = pl011_early_read; return 0; } OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup); OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup); /* * On Qualcomm Datacenter Technologies QDF2400 SOCs affected by * Erratum 44, traditional earlycon can be enabled by specifying * "earlycon=qdf2400_e44,<address>". Any options are ignored. * * Alternatively, you can just specify "earlycon", and the early console * will be enabled with the information from the SPCR table. In this * case, the SPCR code will detect the need for the E44 work-around, * and set the console name to "qdf2400_e44". */ static int __init qdf2400_e44_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; device->con->write = qdf2400_e44_early_write; return 0; } EARLYCON_DECLARE(qdf2400_e44, qdf2400_e44_early_console_setup); #else #define AMBA_CONSOLE NULL #endif static struct uart_driver amba_reg = { .owner = THIS_MODULE, .driver_name = "ttyAMA", .dev_name = "ttyAMA", .major = SERIAL_AMBA_MAJOR, .minor = SERIAL_AMBA_MINOR, .nr = UART_NR, .cons = AMBA_CONSOLE, }; static int pl011_probe_dt_alias(int index, struct device *dev) { struct device_node *np; static bool seen_dev_with_alias = false; static bool seen_dev_without_alias = false; int ret = index; if (!IS_ENABLED(CONFIG_OF)) return ret; np = dev->of_node; if (!np) return ret; ret = of_alias_get_id(np, "serial"); if (ret < 0) { seen_dev_without_alias = true; ret = index; } else { seen_dev_with_alias = true; if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) { dev_warn(dev, "requested serial port %d not available.\n", ret); ret = index; } } if (seen_dev_with_alias && seen_dev_without_alias) dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n"); return ret; } /* unregisters the driver also if no more ports are left */ static void pl011_unregister_port(struct uart_amba_port *uap) { int i; bool busy = false; for (i = 0; i < ARRAY_SIZE(amba_ports); i++) { if (amba_ports[i] == uap) amba_ports[i] = NULL; else if (amba_ports[i]) busy = true; } pl011_dma_remove(uap); if (!busy) uart_unregister_driver(&amba_reg); } static int pl011_find_free_port(void) { int i; for (i = 0; i < ARRAY_SIZE(amba_ports); i++) if (amba_ports[i] == NULL) return i; return -EBUSY; } static int pl011_get_rs485_mode(struct uart_amba_port *uap) { struct uart_port *port = &uap->port; int ret; ret = uart_get_rs485_mode(port); if (ret) return ret; return 0; } static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap, struct resource *mmiobase, int index) { void __iomem *base; int ret; base = devm_ioremap_resource(dev, mmiobase); if (IS_ERR(base)) return PTR_ERR(base); index = pl011_probe_dt_alias(index, dev); uap->port.dev = dev; uap->port.mapbase = mmiobase->start; uap->port.membase = base; uap->port.fifosize = uap->fifosize; uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE); uap->port.flags = UPF_BOOT_AUTOCONF; uap->port.line = index; ret = pl011_get_rs485_mode(uap); if (ret) return ret; amba_ports[index] = uap; return 0; } static int pl011_register_port(struct uart_amba_port *uap) { int ret, i; /* Ensure interrupts from this UART are masked and cleared */ pl011_write(0, uap, REG_IMSC); pl011_write(0xffff, uap, REG_ICR); if (!amba_reg.state) { ret = uart_register_driver(&amba_reg); if (ret < 0) { dev_err(uap->port.dev, "Failed to register AMBA-PL011 driver\n"); for (i = 0; i < ARRAY_SIZE(amba_ports); i++) if (amba_ports[i] == uap) amba_ports[i] = NULL; return ret; } } ret = uart_add_one_port(&amba_reg, &uap->port); if (ret) pl011_unregister_port(uap); return ret; } static const struct serial_rs485 pl011_rs485_supported = { .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX, .delay_rts_before_send = 1, .delay_rts_after_send = 1, }; static int pl011_probe(struct amba_device *dev, const struct amba_id *id) { struct uart_amba_port *uap; struct vendor_data *vendor = id->data; int portnr, ret; u32 val; portnr = pl011_find_free_port(); if (portnr < 0) return portnr; uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port), GFP_KERNEL); if (!uap) return -ENOMEM; uap->clk = devm_clk_get(&dev->dev, NULL); if (IS_ERR(uap->clk)) return PTR_ERR(uap->clk); uap->reg_offset = vendor->reg_offset; uap->vendor = vendor; uap->fifosize = vendor->get_fifosize(dev); uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM; uap->port.irq = dev->irq[0]; uap->port.ops = &amba_pl011_pops; uap->port.rs485_config = pl011_rs485_config; uap->port.rs485_supported = pl011_rs485_supported; snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev)); if (device_property_read_u32(&dev->dev, "reg-io-width", &val) == 0) { switch (val) { case 1: uap->port.iotype = UPIO_MEM; break; case 4: uap->port.iotype = UPIO_MEM32; break; default: dev_warn(&dev->dev, "unsupported reg-io-width (%d)\n", val); return -EINVAL; } } ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr); if (ret) return ret; amba_set_drvdata(dev, uap); return pl011_register_port(uap); } static void pl011_remove(struct amba_device *dev) { struct uart_amba_port *uap = amba_get_drvdata(dev); uart_remove_one_port(&amba_reg, &uap->port); pl011_unregister_port(uap); } #ifdef CONFIG_PM_SLEEP static int pl011_suspend(struct device *dev) { struct uart_amba_port *uap = dev_get_drvdata(dev); if (!uap) return -EINVAL; return uart_suspend_port(&amba_reg, &uap->port); } static int pl011_resume(struct device *dev) { struct uart_amba_port *uap = dev_get_drvdata(dev); if (!uap) return -EINVAL; return uart_resume_port(&amba_reg, &uap->port); } #endif static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume); static int sbsa_uart_probe(struct platform_device *pdev) { struct uart_amba_port *uap; struct resource *r; int portnr, ret; int baudrate; /* * Check the mandatory baud rate parameter in the DT node early * so that we can easily exit with the error. */ if (pdev->dev.of_node) { struct device_node *np = pdev->dev.of_node; ret = of_property_read_u32(np, "current-speed", &baudrate); if (ret) return ret; } else { baudrate = 115200; } portnr = pl011_find_free_port(); if (portnr < 0) return portnr; uap = devm_kzalloc(&pdev->dev, sizeof(struct uart_amba_port), GFP_KERNEL); if (!uap) return -ENOMEM; ret = platform_get_irq(pdev, 0); if (ret < 0) return ret; uap->port.irq = ret; #ifdef CONFIG_ACPI_SPCR_TABLE if (qdf2400_e44_present) { dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n"); uap->vendor = &vendor_qdt_qdf2400_e44; } else #endif uap->vendor = &vendor_sbsa; uap->reg_offset = uap->vendor->reg_offset; uap->fifosize = 32; uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM; uap->port.ops = &sbsa_uart_pops; uap->fixed_baud = baudrate; snprintf(uap->type, sizeof(uap->type), "SBSA"); r = platform_get_resource(pdev, IORESOURCE_MEM, 0); ret = pl011_setup_port(&pdev->dev, uap, r, portnr); if (ret) return ret; platform_set_drvdata(pdev, uap); return pl011_register_port(uap); } static int sbsa_uart_remove(struct platform_device *pdev) { struct uart_amba_port *uap = platform_get_drvdata(pdev); uart_remove_one_port(&amba_reg, &uap->port); pl011_unregister_port(uap); return 0; } static const struct of_device_id sbsa_uart_of_match[] = { { .compatible = "arm,sbsa-uart", }, {}, }; MODULE_DEVICE_TABLE(of, sbsa_uart_of_match); static const struct acpi_device_id __maybe_unused sbsa_uart_acpi_match[] = { { "ARMH0011", 0 }, { "ARMHB000", 0 }, {}, }; MODULE_DEVICE_TABLE(acpi, sbsa_uart_acpi_match); static struct platform_driver arm_sbsa_uart_platform_driver = { .probe = sbsa_uart_probe, .remove = sbsa_uart_remove, .driver = { .name = "sbsa-uart", .pm = &pl011_dev_pm_ops, .of_match_table = of_match_ptr(sbsa_uart_of_match), .acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match), .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011), }, }; static const struct amba_id pl011_ids[] = { { .id = 0x00041011, .mask = 0x000fffff, .data = &vendor_arm, }, { .id = 0x00380802, .mask = 0x00ffffff, .data = &vendor_st, }, { 0, 0 }, }; MODULE_DEVICE_TABLE(amba, pl011_ids); static struct amba_driver pl011_driver = { .drv = { .name = "uart-pl011", .pm = &pl011_dev_pm_ops, .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011), }, .id_table = pl011_ids, .probe = pl011_probe, .remove = pl011_remove, }; static int __init pl011_init(void) { printk(KERN_INFO "Serial: AMBA PL011 UART driver\n"); if (platform_driver_register(&arm_sbsa_uart_platform_driver)) pr_warn("could not register SBSA UART platform driver\n"); return amba_driver_register(&pl011_driver); } static void __exit pl011_exit(void) { platform_driver_unregister(&arm_sbsa_uart_platform_driver); amba_driver_unregister(&pl011_driver); } /* * While this can be a module, if builtin it's most likely the console * So let's leave module_exit but move module_init to an earlier place */ arch_initcall(pl011_init); module_exit(pl011_exit); MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd"); MODULE_DESCRIPTION("ARM AMBA serial port driver"); MODULE_LICENSE("GPL");
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