| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Alexandre Torgue | 2310 | 22.01% | 7 | 5.98% |
| Erwan Le Ray | 2185 | 20.82% | 46 | 39.32% |
| Maxime Coquelin | 2059 | 19.62% | 1 | 0.85% |
| Valentin CARON - foss | 1864 | 17.76% | 15 | 12.82% |
| Fabrice Gasnier | 579 | 5.52% | 4 | 3.42% |
| Bich Hemon | 520 | 4.95% | 3 | 2.56% |
| Lukas Wunner | 235 | 2.24% | 2 | 1.71% |
| Manivannan Sadhasivam | 156 | 1.49% | 1 | 0.85% |
| Marek Vašut | 149 | 1.42% | 5 | 4.27% |
| Ilpo Järvinen | 81 | 0.77% | 5 | 4.27% |
| Jiri Slaby (SUSE) | 68 | 0.65% | 2 | 1.71% |
| Martin Devera | 55 | 0.52% | 1 | 0.85% |
| Gerald Baeza | 55 | 0.52% | 2 | 1.71% |
| Stephen Boyd | 41 | 0.39% | 1 | 0.85% |
| Uwe Kleine-König | 40 | 0.38% | 3 | 2.56% |
| Thomas Gleixner | 28 | 0.27% | 1 | 0.85% |
| Ben Dooks | 12 | 0.11% | 1 | 0.85% |
| Amelie Delaunay | 9 | 0.09% | 1 | 0.85% |
| Jiri Slaby | 8 | 0.08% | 2 | 1.71% |
| Dmitry Safonov | 7 | 0.07% | 1 | 0.85% |
| Lino Sanfilippo | 7 | 0.07% | 1 | 0.85% |
| Johan Hovold | 7 | 0.07% | 1 | 0.85% |
| tangbin | 5 | 0.05% | 2 | 1.71% |
| Russell King | 4 | 0.04% | 2 | 1.71% |
| Ren Zhijie | 3 | 0.03% | 1 | 0.85% |
| Christoph Niedermaier | 2 | 0.02% | 1 | 0.85% |
| Baoyou Xie | 2 | 0.02% | 1 | 0.85% |
| Arnd Bergmann | 2 | 0.02% | 1 | 0.85% |
| David Howells | 2 | 0.02% | 1 | 0.85% |
| Alan Cox | 1 | 0.01% | 1 | 0.85% |
| Greg Kroah-Hartman | 1 | 0.01% | 1 | 0.85% |
| Total | 10497 | 117 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) Maxime Coquelin 2015 * Copyright (C) STMicroelectronics SA 2017 * Authors: Maxime Coquelin <mcoquelin.stm32@gmail.com> * Gerald Baeza <gerald.baeza@foss.st.com> * Erwan Le Ray <erwan.leray@foss.st.com> * * Inspired by st-asc.c from STMicroelectronics (c) */ #include <linux/bitfield.h> #include <linux/clk.h> #include <linux/console.h> #include <linux/delay.h> #include <linux/dma-direction.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/io.h> #include <linux/iopoll.h> #include <linux/irq.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_platform.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/pm_wakeirq.h> #include <linux/serial_core.h> #include <linux/serial.h> #include <linux/spinlock.h> #include <linux/sysrq.h> #include <linux/tty_flip.h> #include <linux/tty.h> #include "serial_mctrl_gpio.h" #include "stm32-usart.h" /* Register offsets */ static struct stm32_usart_info __maybe_unused stm32f4_info = { .ofs = { .isr = 0x00, .rdr = 0x04, .tdr = 0x04, .brr = 0x08, .cr1 = 0x0c, .cr2 = 0x10, .cr3 = 0x14, .gtpr = 0x18, .rtor = UNDEF_REG, .rqr = UNDEF_REG, .icr = UNDEF_REG, .presc = UNDEF_REG, .hwcfgr1 = UNDEF_REG, }, .cfg = { .uart_enable_bit = 13, .has_7bits_data = false, } }; static struct stm32_usart_info __maybe_unused stm32f7_info = { .ofs = { .cr1 = 0x00, .cr2 = 0x04, .cr3 = 0x08, .brr = 0x0c, .gtpr = 0x10, .rtor = 0x14, .rqr = 0x18, .isr = 0x1c, .icr = 0x20, .rdr = 0x24, .tdr = 0x28, .presc = UNDEF_REG, .hwcfgr1 = UNDEF_REG, }, .cfg = { .uart_enable_bit = 0, .has_7bits_data = true, .has_swap = true, } }; static struct stm32_usart_info __maybe_unused stm32h7_info = { .ofs = { .cr1 = 0x00, .cr2 = 0x04, .cr3 = 0x08, .brr = 0x0c, .gtpr = 0x10, .rtor = 0x14, .rqr = 0x18, .isr = 0x1c, .icr = 0x20, .rdr = 0x24, .tdr = 0x28, .presc = 0x2c, .hwcfgr1 = 0x3f0, }, .cfg = { .uart_enable_bit = 0, .has_7bits_data = true, .has_swap = true, .has_wakeup = true, .has_fifo = true, } }; static void stm32_usart_stop_tx(struct uart_port *port); static void stm32_usart_transmit_chars(struct uart_port *port); static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch); static inline struct stm32_port *to_stm32_port(struct uart_port *port) { return container_of(port, struct stm32_port, port); } static void stm32_usart_set_bits(struct uart_port *port, u32 reg, u32 bits) { u32 val; val = readl_relaxed(port->membase + reg); val |= bits; writel_relaxed(val, port->membase + reg); } static void stm32_usart_clr_bits(struct uart_port *port, u32 reg, u32 bits) { u32 val; val = readl_relaxed(port->membase + reg); val &= ~bits; writel_relaxed(val, port->membase + reg); } static unsigned int stm32_usart_tx_empty(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; if (readl_relaxed(port->membase + ofs->isr) & USART_SR_TC) return TIOCSER_TEMT; return 0; } static void stm32_usart_rs485_rts_enable(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); struct serial_rs485 *rs485conf = &port->rs485; if (stm32_port->hw_flow_control || !(rs485conf->flags & SER_RS485_ENABLED)) return; if (rs485conf->flags & SER_RS485_RTS_ON_SEND) { mctrl_gpio_set(stm32_port->gpios, stm32_port->port.mctrl | TIOCM_RTS); } else { mctrl_gpio_set(stm32_port->gpios, stm32_port->port.mctrl & ~TIOCM_RTS); } } static void stm32_usart_rs485_rts_disable(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); struct serial_rs485 *rs485conf = &port->rs485; if (stm32_port->hw_flow_control || !(rs485conf->flags & SER_RS485_ENABLED)) return; if (rs485conf->flags & SER_RS485_RTS_ON_SEND) { mctrl_gpio_set(stm32_port->gpios, stm32_port->port.mctrl & ~TIOCM_RTS); } else { mctrl_gpio_set(stm32_port->gpios, stm32_port->port.mctrl | TIOCM_RTS); } } static void stm32_usart_config_reg_rs485(u32 *cr1, u32 *cr3, u32 delay_ADE, u32 delay_DDE, u32 baud) { u32 rs485_deat_dedt; u32 rs485_deat_dedt_max = (USART_CR1_DEAT_MASK >> USART_CR1_DEAT_SHIFT); bool over8; *cr3 |= USART_CR3_DEM; over8 = *cr1 & USART_CR1_OVER8; *cr1 &= ~(USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK); if (over8) rs485_deat_dedt = delay_ADE * baud * 8; else rs485_deat_dedt = delay_ADE * baud * 16; rs485_deat_dedt = DIV_ROUND_CLOSEST(rs485_deat_dedt, 1000); rs485_deat_dedt = rs485_deat_dedt > rs485_deat_dedt_max ? rs485_deat_dedt_max : rs485_deat_dedt; rs485_deat_dedt = (rs485_deat_dedt << USART_CR1_DEAT_SHIFT) & USART_CR1_DEAT_MASK; *cr1 |= rs485_deat_dedt; if (over8) rs485_deat_dedt = delay_DDE * baud * 8; else rs485_deat_dedt = delay_DDE * baud * 16; rs485_deat_dedt = DIV_ROUND_CLOSEST(rs485_deat_dedt, 1000); rs485_deat_dedt = rs485_deat_dedt > rs485_deat_dedt_max ? rs485_deat_dedt_max : rs485_deat_dedt; rs485_deat_dedt = (rs485_deat_dedt << USART_CR1_DEDT_SHIFT) & USART_CR1_DEDT_MASK; *cr1 |= rs485_deat_dedt; } static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *termios, struct serial_rs485 *rs485conf) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; const struct stm32_usart_config *cfg = &stm32_port->info->cfg; u32 usartdiv, baud, cr1, cr3; bool over8; stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); if (rs485conf->flags & SER_RS485_ENABLED) { cr1 = readl_relaxed(port->membase + ofs->cr1); cr3 = readl_relaxed(port->membase + ofs->cr3); usartdiv = readl_relaxed(port->membase + ofs->brr); usartdiv = usartdiv & GENMASK(15, 0); over8 = cr1 & USART_CR1_OVER8; if (over8) usartdiv = usartdiv | (usartdiv & GENMASK(4, 0)) << USART_BRR_04_R_SHIFT; baud = DIV_ROUND_CLOSEST(port->uartclk, usartdiv); stm32_usart_config_reg_rs485(&cr1, &cr3, rs485conf->delay_rts_before_send, rs485conf->delay_rts_after_send, baud); if (rs485conf->flags & SER_RS485_RTS_ON_SEND) cr3 &= ~USART_CR3_DEP; else cr3 |= USART_CR3_DEP; writel_relaxed(cr3, port->membase + ofs->cr3); writel_relaxed(cr1, port->membase + ofs->cr1); if (!port->rs485_rx_during_tx_gpio) rs485conf->flags |= SER_RS485_RX_DURING_TX; } else { stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DEM | USART_CR3_DEP); stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK); } stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); /* Adjust RTS polarity in case it's driven in software */ if (stm32_usart_tx_empty(port)) stm32_usart_rs485_rts_disable(port); else stm32_usart_rs485_rts_enable(port); return 0; } static int stm32_usart_init_rs485(struct uart_port *port, struct platform_device *pdev) { struct serial_rs485 *rs485conf = &port->rs485; rs485conf->flags = 0; rs485conf->delay_rts_before_send = 0; rs485conf->delay_rts_after_send = 0; if (!pdev->dev.of_node) return -ENODEV; return uart_get_rs485_mode(port); } static bool stm32_usart_rx_dma_started(struct stm32_port *stm32_port) { return stm32_port->rx_ch ? stm32_port->rx_dma_busy : false; } static void stm32_usart_rx_dma_terminate(struct stm32_port *stm32_port) { dmaengine_terminate_async(stm32_port->rx_ch); stm32_port->rx_dma_busy = false; } static int stm32_usart_dma_pause_resume(struct stm32_port *stm32_port, struct dma_chan *chan, enum dma_status expected_status, int dmaengine_pause_or_resume(struct dma_chan *), bool stm32_usart_xx_dma_started(struct stm32_port *), void stm32_usart_xx_dma_terminate(struct stm32_port *)) { struct uart_port *port = &stm32_port->port; enum dma_status dma_status; int ret; if (!stm32_usart_xx_dma_started(stm32_port)) return -EPERM; dma_status = dmaengine_tx_status(chan, chan->cookie, NULL); if (dma_status != expected_status) return -EAGAIN; ret = dmaengine_pause_or_resume(chan); if (ret) { dev_err(port->dev, "DMA failed with error code: %d\n", ret); stm32_usart_xx_dma_terminate(stm32_port); } return ret; } static int stm32_usart_rx_dma_pause(struct stm32_port *stm32_port) { return stm32_usart_dma_pause_resume(stm32_port, stm32_port->rx_ch, DMA_IN_PROGRESS, dmaengine_pause, stm32_usart_rx_dma_started, stm32_usart_rx_dma_terminate); } static int stm32_usart_rx_dma_resume(struct stm32_port *stm32_port) { return stm32_usart_dma_pause_resume(stm32_port, stm32_port->rx_ch, DMA_PAUSED, dmaengine_resume, stm32_usart_rx_dma_started, stm32_usart_rx_dma_terminate); } /* Return true when data is pending (in pio mode), and false when no data is pending. */ static bool stm32_usart_pending_rx_pio(struct uart_port *port, u32 *sr) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; *sr = readl_relaxed(port->membase + ofs->isr); /* Get pending characters in RDR or FIFO */ if (*sr & USART_SR_RXNE) { /* Get all pending characters from the RDR or the FIFO when using interrupts */ if (!stm32_usart_rx_dma_started(stm32_port)) return true; /* Handle only RX data errors when using DMA */ if (*sr & USART_SR_ERR_MASK) return true; } return false; } static u8 stm32_usart_get_char_pio(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; unsigned long c; c = readl_relaxed(port->membase + ofs->rdr); /* Apply RDR data mask */ c &= stm32_port->rdr_mask; return c; } static unsigned int stm32_usart_receive_chars_pio(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; unsigned int size = 0; u32 sr; u8 c, flag; while (stm32_usart_pending_rx_pio(port, &sr)) { sr |= USART_SR_DUMMY_RX; flag = TTY_NORMAL; /* * Status bits has to be cleared before reading the RDR: * In FIFO mode, reading the RDR will pop the next data * (if any) along with its status bits into the SR. * Not doing so leads to misalignement between RDR and SR, * and clear status bits of the next rx data. * * Clear errors flags for stm32f7 and stm32h7 compatible * devices. On stm32f4 compatible devices, the error bit is * cleared by the sequence [read SR - read DR]. */ if ((sr & USART_SR_ERR_MASK) && ofs->icr != UNDEF_REG) writel_relaxed(sr & USART_SR_ERR_MASK, port->membase + ofs->icr); c = stm32_usart_get_char_pio(port); port->icount.rx++; size++; if (sr & USART_SR_ERR_MASK) { if (sr & USART_SR_ORE) { port->icount.overrun++; } else if (sr & USART_SR_PE) { port->icount.parity++; } else if (sr & USART_SR_FE) { /* Break detection if character is null */ if (!c) { port->icount.brk++; if (uart_handle_break(port)) continue; } else { port->icount.frame++; } } sr &= port->read_status_mask; if (sr & USART_SR_PE) { flag = TTY_PARITY; } else if (sr & USART_SR_FE) { if (!c) flag = TTY_BREAK; else flag = TTY_FRAME; } } if (uart_prepare_sysrq_char(port, c)) continue; uart_insert_char(port, sr, USART_SR_ORE, c, flag); } return size; } static void stm32_usart_push_buffer_dma(struct uart_port *port, unsigned int dma_size) { struct stm32_port *stm32_port = to_stm32_port(port); struct tty_port *ttyport = &stm32_port->port.state->port; unsigned char *dma_start; int dma_count, i; dma_start = stm32_port->rx_buf + (RX_BUF_L - stm32_port->last_res); /* * Apply rdr_mask on buffer in order to mask parity bit. * This loop is useless in cs8 mode because DMA copies only * 8 bits and already ignores parity bit. */ if (!(stm32_port->rdr_mask == (BIT(8) - 1))) for (i = 0; i < dma_size; i++) *(dma_start + i) &= stm32_port->rdr_mask; dma_count = tty_insert_flip_string(ttyport, dma_start, dma_size); port->icount.rx += dma_count; if (dma_count != dma_size) port->icount.buf_overrun++; stm32_port->last_res -= dma_count; if (stm32_port->last_res == 0) stm32_port->last_res = RX_BUF_L; } static unsigned int stm32_usart_receive_chars_dma(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); unsigned int dma_size, size = 0; /* DMA buffer is configured in cyclic mode and handles the rollback of the buffer. */ if (stm32_port->rx_dma_state.residue > stm32_port->last_res) { /* Conditional first part: from last_res to end of DMA buffer */ dma_size = stm32_port->last_res; stm32_usart_push_buffer_dma(port, dma_size); size = dma_size; } dma_size = stm32_port->last_res - stm32_port->rx_dma_state.residue; stm32_usart_push_buffer_dma(port, dma_size); size += dma_size; return size; } static unsigned int stm32_usart_receive_chars(struct uart_port *port, bool force_dma_flush) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; enum dma_status rx_dma_status; u32 sr; unsigned int size = 0; if (stm32_usart_rx_dma_started(stm32_port) || force_dma_flush) { rx_dma_status = dmaengine_tx_status(stm32_port->rx_ch, stm32_port->rx_ch->cookie, &stm32_port->rx_dma_state); if (rx_dma_status == DMA_IN_PROGRESS || rx_dma_status == DMA_PAUSED) { /* Empty DMA buffer */ size = stm32_usart_receive_chars_dma(port); sr = readl_relaxed(port->membase + ofs->isr); if (sr & USART_SR_ERR_MASK) { /* Disable DMA request line */ stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR); /* Switch to PIO mode to handle the errors */ size += stm32_usart_receive_chars_pio(port); /* Switch back to DMA mode */ stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAR); } } else { /* Disable RX DMA */ stm32_usart_rx_dma_terminate(stm32_port); /* Fall back to interrupt mode */ dev_dbg(port->dev, "DMA error, fallback to irq mode\n"); size = stm32_usart_receive_chars_pio(port); } } else { size = stm32_usart_receive_chars_pio(port); } return size; } static void stm32_usart_rx_dma_complete(void *arg) { struct uart_port *port = arg; struct tty_port *tport = &port->state->port; unsigned int size; unsigned long flags; uart_port_lock_irqsave(port, &flags); size = stm32_usart_receive_chars(port, false); uart_unlock_and_check_sysrq_irqrestore(port, flags); if (size) tty_flip_buffer_push(tport); } static int stm32_usart_rx_dma_start_or_resume(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); struct dma_async_tx_descriptor *desc; enum dma_status rx_dma_status; int ret; if (stm32_port->throttled) return 0; if (stm32_port->rx_dma_busy) { rx_dma_status = dmaengine_tx_status(stm32_port->rx_ch, stm32_port->rx_ch->cookie, NULL); if (rx_dma_status == DMA_IN_PROGRESS) return 0; if (rx_dma_status == DMA_PAUSED && !stm32_usart_rx_dma_resume(stm32_port)) return 0; dev_err(port->dev, "DMA failed : status error.\n"); stm32_usart_rx_dma_terminate(stm32_port); } stm32_port->rx_dma_busy = true; stm32_port->last_res = RX_BUF_L; /* Prepare a DMA cyclic transaction */ desc = dmaengine_prep_dma_cyclic(stm32_port->rx_ch, stm32_port->rx_dma_buf, RX_BUF_L, RX_BUF_P, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!desc) { dev_err(port->dev, "rx dma prep cyclic failed\n"); stm32_port->rx_dma_busy = false; return -ENODEV; } desc->callback = stm32_usart_rx_dma_complete; desc->callback_param = port; /* Push current DMA transaction in the pending queue */ ret = dma_submit_error(dmaengine_submit(desc)); if (ret) { dmaengine_terminate_sync(stm32_port->rx_ch); stm32_port->rx_dma_busy = false; return ret; } /* Issue pending DMA requests */ dma_async_issue_pending(stm32_port->rx_ch); return 0; } static void stm32_usart_tx_dma_terminate(struct stm32_port *stm32_port) { dmaengine_terminate_async(stm32_port->tx_ch); stm32_port->tx_dma_busy = false; } static bool stm32_usart_tx_dma_started(struct stm32_port *stm32_port) { /* * We cannot use the function "dmaengine_tx_status" to know the * status of DMA. This function does not show if the "dma complete" * callback of the DMA transaction has been called. So we prefer * to use "tx_dma_busy" flag to prevent dual DMA transaction at the * same time. */ return stm32_port->tx_dma_busy; } static int stm32_usart_tx_dma_pause(struct stm32_port *stm32_port) { return stm32_usart_dma_pause_resume(stm32_port, stm32_port->tx_ch, DMA_IN_PROGRESS, dmaengine_pause, stm32_usart_tx_dma_started, stm32_usart_tx_dma_terminate); } static int stm32_usart_tx_dma_resume(struct stm32_port *stm32_port) { return stm32_usart_dma_pause_resume(stm32_port, stm32_port->tx_ch, DMA_PAUSED, dmaengine_resume, stm32_usart_tx_dma_started, stm32_usart_tx_dma_terminate); } static void stm32_usart_tx_dma_complete(void *arg) { struct uart_port *port = arg; struct stm32_port *stm32port = to_stm32_port(port); unsigned long flags; stm32_usart_tx_dma_terminate(stm32port); /* Let's see if we have pending data to send */ uart_port_lock_irqsave(port, &flags); stm32_usart_transmit_chars(port); uart_port_unlock_irqrestore(port, flags); } static void stm32_usart_tx_interrupt_enable(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; /* * Enables TX FIFO threashold irq when FIFO is enabled, * or TX empty irq when FIFO is disabled */ if (stm32_port->fifoen && stm32_port->txftcfg >= 0) stm32_usart_set_bits(port, ofs->cr3, USART_CR3_TXFTIE); else stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TXEIE); } static void stm32_usart_tc_interrupt_enable(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TCIE); } static void stm32_usart_tx_interrupt_disable(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; if (stm32_port->fifoen && stm32_port->txftcfg >= 0) stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_TXFTIE); else stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TXEIE); } static void stm32_usart_tc_interrupt_disable(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_TCIE); } static void stm32_usart_transmit_chars_pio(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct tty_port *tport = &port->state->port; while (1) { unsigned char ch; /* Check that TDR is empty before filling FIFO */ if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE)) break; if (!uart_fifo_get(port, &ch)) break; writel_relaxed(ch, port->membase + ofs->tdr); } /* rely on TXE irq (mask or unmask) for sending remaining data */ if (kfifo_is_empty(&tport->xmit_fifo)) stm32_usart_tx_interrupt_disable(port); else stm32_usart_tx_interrupt_enable(port); } static void stm32_usart_transmit_chars_dma(struct uart_port *port) { struct stm32_port *stm32port = to_stm32_port(port); struct tty_port *tport = &port->state->port; struct dma_async_tx_descriptor *desc = NULL; unsigned int count; int ret; if (stm32_usart_tx_dma_started(stm32port)) { ret = stm32_usart_tx_dma_resume(stm32port); if (ret < 0 && ret != -EAGAIN) goto fallback_err; return; } count = kfifo_out_peek(&tport->xmit_fifo, &stm32port->tx_buf[0], TX_BUF_L); desc = dmaengine_prep_slave_single(stm32port->tx_ch, stm32port->tx_dma_buf, count, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); if (!desc) goto fallback_err; /* * Set "tx_dma_busy" flag. This flag will be released when * dmaengine_terminate_async will be called. This flag helps * transmit_chars_dma not to start another DMA transaction * if the callback of the previous is not yet called. */ stm32port->tx_dma_busy = true; desc->callback = stm32_usart_tx_dma_complete; desc->callback_param = port; /* Push current DMA TX transaction in the pending queue */ /* DMA no yet started, safe to free resources */ ret = dma_submit_error(dmaengine_submit(desc)); if (ret) { dev_err(port->dev, "DMA failed with error code: %d\n", ret); stm32_usart_tx_dma_terminate(stm32port); goto fallback_err; } /* Issue pending DMA TX requests */ dma_async_issue_pending(stm32port->tx_ch); uart_xmit_advance(port, count); return; fallback_err: stm32_usart_transmit_chars_pio(port); } static void stm32_usart_transmit_chars(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct tty_port *tport = &port->state->port; u32 isr; int ret; if (!stm32_port->hw_flow_control && port->rs485.flags & SER_RS485_ENABLED && (port->x_char || !(kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)))) { stm32_usart_tc_interrupt_disable(port); stm32_usart_rs485_rts_enable(port); } if (port->x_char) { /* dma terminate may have been called in case of dma pause failure */ stm32_usart_tx_dma_pause(stm32_port); /* Check that TDR is empty before filling FIFO */ ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, isr, (isr & USART_SR_TXE), 10, 1000); if (ret) dev_warn(port->dev, "1 character may be erased\n"); writel_relaxed(port->x_char, port->membase + ofs->tdr); port->x_char = 0; port->icount.tx++; /* dma terminate may have been called in case of dma resume failure */ stm32_usart_tx_dma_resume(stm32_port); return; } if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) { stm32_usart_tx_interrupt_disable(port); return; } if (ofs->icr == UNDEF_REG) stm32_usart_clr_bits(port, ofs->isr, USART_SR_TC); else writel_relaxed(USART_ICR_TCCF, port->membase + ofs->icr); if (stm32_port->tx_ch) stm32_usart_transmit_chars_dma(port); else stm32_usart_transmit_chars_pio(port); if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) uart_write_wakeup(port); if (kfifo_is_empty(&tport->xmit_fifo)) { stm32_usart_tx_interrupt_disable(port); if (!stm32_port->hw_flow_control && port->rs485.flags & SER_RS485_ENABLED) { stm32_usart_tc_interrupt_enable(port); } } } static irqreturn_t stm32_usart_interrupt(int irq, void *ptr) { struct uart_port *port = ptr; struct tty_port *tport = &port->state->port; struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; u32 sr; unsigned int size; irqreturn_t ret = IRQ_NONE; sr = readl_relaxed(port->membase + ofs->isr); if (!stm32_port->hw_flow_control && port->rs485.flags & SER_RS485_ENABLED && (sr & USART_SR_TC)) { stm32_usart_tc_interrupt_disable(port); stm32_usart_rs485_rts_disable(port); ret = IRQ_HANDLED; } if ((sr & USART_SR_RTOF) && ofs->icr != UNDEF_REG) { writel_relaxed(USART_ICR_RTOCF, port->membase + ofs->icr); ret = IRQ_HANDLED; } if ((sr & USART_SR_WUF) && ofs->icr != UNDEF_REG) { /* Clear wake up flag and disable wake up interrupt */ writel_relaxed(USART_ICR_WUCF, port->membase + ofs->icr); stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE); if (irqd_is_wakeup_set(irq_get_irq_data(port->irq))) pm_wakeup_event(tport->tty->dev, 0); ret = IRQ_HANDLED; } /* * rx errors in dma mode has to be handled ASAP to avoid overrun as the DMA request * line has been masked by HW and rx data are stacking in FIFO. */ if (!stm32_port->throttled) { if (((sr & USART_SR_RXNE) && !stm32_usart_rx_dma_started(stm32_port)) || ((sr & USART_SR_ERR_MASK) && stm32_usart_rx_dma_started(stm32_port))) { uart_port_lock(port); size = stm32_usart_receive_chars(port, false); uart_unlock_and_check_sysrq(port); if (size) tty_flip_buffer_push(tport); ret = IRQ_HANDLED; } } if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch)) { uart_port_lock(port); stm32_usart_transmit_chars(port); uart_port_unlock(port); ret = IRQ_HANDLED; } /* Receiver timeout irq for DMA RX */ if (stm32_usart_rx_dma_started(stm32_port) && !stm32_port->throttled) { uart_port_lock(port); size = stm32_usart_receive_chars(port, false); uart_unlock_and_check_sysrq(port); if (size) tty_flip_buffer_push(tport); ret = IRQ_HANDLED; } return ret; } static void stm32_usart_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS)) stm32_usart_set_bits(port, ofs->cr3, USART_CR3_RTSE); else stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_RTSE); mctrl_gpio_set(stm32_port->gpios, mctrl); } static unsigned int stm32_usart_get_mctrl(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); unsigned int ret; /* This routine is used to get signals of: DCD, DSR, RI, and CTS */ ret = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; return mctrl_gpio_get(stm32_port->gpios, &ret); } static void stm32_usart_enable_ms(struct uart_port *port) { mctrl_gpio_enable_ms(to_stm32_port(port)->gpios); } static void stm32_usart_disable_ms(struct uart_port *port) { mctrl_gpio_disable_ms(to_stm32_port(port)->gpios); } /* Transmit stop */ static void stm32_usart_stop_tx(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); stm32_usart_tx_interrupt_disable(port); /* dma terminate may have been called in case of dma pause failure */ stm32_usart_tx_dma_pause(stm32_port); stm32_usart_rs485_rts_disable(port); } /* There are probably characters waiting to be transmitted. */ static void stm32_usart_start_tx(struct uart_port *port) { struct tty_port *tport = &port->state->port; if (kfifo_is_empty(&tport->xmit_fifo) && !port->x_char) { stm32_usart_rs485_rts_disable(port); return; } stm32_usart_rs485_rts_enable(port); stm32_usart_transmit_chars(port); } /* Flush the transmit buffer. */ static void stm32_usart_flush_buffer(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); if (stm32_port->tx_ch) stm32_usart_tx_dma_terminate(stm32_port); } /* Throttle the remote when input buffer is about to overflow. */ static void stm32_usart_throttle(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; unsigned long flags; uart_port_lock_irqsave(port, &flags); /* * Pause DMA transfer, so the RX data gets queued into the FIFO. * Hardware flow control is triggered when RX FIFO is full. */ stm32_usart_rx_dma_pause(stm32_port); stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq); if (stm32_port->cr3_irq) stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq); stm32_port->throttled = true; uart_port_unlock_irqrestore(port, flags); } /* Unthrottle the remote, the input buffer can now accept data. */ static void stm32_usart_unthrottle(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; unsigned long flags; uart_port_lock_irqsave(port, &flags); stm32_usart_set_bits(port, ofs->cr1, stm32_port->cr1_irq); if (stm32_port->cr3_irq) stm32_usart_set_bits(port, ofs->cr3, stm32_port->cr3_irq); stm32_port->throttled = false; /* * Switch back to DMA mode (resume DMA). * Hardware flow control is stopped when FIFO is not full any more. */ if (stm32_port->rx_ch) stm32_usart_rx_dma_start_or_resume(port); uart_port_unlock_irqrestore(port, flags); } /* Receive stop */ static void stm32_usart_stop_rx(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; /* Disable DMA request line. */ stm32_usart_rx_dma_pause(stm32_port); stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq); if (stm32_port->cr3_irq) stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq); } static void stm32_usart_break_ctl(struct uart_port *port, int break_state) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; unsigned long flags; spin_lock_irqsave(&port->lock, flags); if (break_state) stm32_usart_set_bits(port, ofs->rqr, USART_RQR_SBKRQ); else stm32_usart_clr_bits(port, ofs->rqr, USART_RQR_SBKRQ); spin_unlock_irqrestore(&port->lock, flags); } static int stm32_usart_startup(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; const struct stm32_usart_config *cfg = &stm32_port->info->cfg; const char *name = to_platform_device(port->dev)->name; u32 val; int ret; ret = request_irq(port->irq, stm32_usart_interrupt, IRQF_NO_SUSPEND, name, port); if (ret) return ret; if (stm32_port->swap) { val = readl_relaxed(port->membase + ofs->cr2); val |= USART_CR2_SWAP; writel_relaxed(val, port->membase + ofs->cr2); } stm32_port->throttled = false; /* RX FIFO Flush */ if (ofs->rqr != UNDEF_REG) writel_relaxed(USART_RQR_RXFRQ, port->membase + ofs->rqr); if (stm32_port->rx_ch) { ret = stm32_usart_rx_dma_start_or_resume(port); if (ret) { free_irq(port->irq, port); return ret; } } /* RX enabling */ val = stm32_port->cr1_irq | USART_CR1_RE | BIT(cfg->uart_enable_bit); stm32_usart_set_bits(port, ofs->cr1, val); return 0; } static void stm32_usart_shutdown(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; const struct stm32_usart_config *cfg = &stm32_port->info->cfg; u32 val, isr; int ret; if (stm32_usart_tx_dma_started(stm32_port)) stm32_usart_tx_dma_terminate(stm32_port); if (stm32_port->tx_ch) stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAT); /* Disable modem control interrupts */ stm32_usart_disable_ms(port); val = USART_CR1_TXEIE | USART_CR1_TE; val |= stm32_port->cr1_irq | USART_CR1_RE; val |= BIT(cfg->uart_enable_bit); if (stm32_port->fifoen) val |= USART_CR1_FIFOEN; ret = readl_relaxed_poll_timeout(port->membase + ofs->isr, isr, (isr & USART_SR_TC), 10, 100000); /* Send the TC error message only when ISR_TC is not set */ if (ret) dev_err(port->dev, "Transmission is not complete\n"); /* Disable RX DMA. */ if (stm32_port->rx_ch) { stm32_usart_rx_dma_terminate(stm32_port); dmaengine_synchronize(stm32_port->rx_ch); } /* flush RX & TX FIFO */ if (ofs->rqr != UNDEF_REG) writel_relaxed(USART_RQR_TXFRQ | USART_RQR_RXFRQ, port->membase + ofs->rqr); stm32_usart_clr_bits(port, ofs->cr1, val); free_irq(port->irq, port); } static const unsigned int stm32_usart_presc_val[] = {1, 2, 4, 6, 8, 10, 12, 16, 32, 64, 128, 256}; static void stm32_usart_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; const struct stm32_usart_config *cfg = &stm32_port->info->cfg; struct serial_rs485 *rs485conf = &port->rs485; unsigned int baud, bits, uart_clk, uart_clk_pres; u32 usartdiv, mantissa, fraction, oversampling; tcflag_t cflag = termios->c_cflag; u32 cr1, cr2, cr3, isr, brr, presc; unsigned long flags; int ret; if (!stm32_port->hw_flow_control) cflag &= ~CRTSCTS; uart_clk = clk_get_rate(stm32_port->clk); baud = uart_get_baud_rate(port, termios, old, 0, uart_clk / 8); uart_port_lock_irqsave(port, &flags); ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, isr, (isr & USART_SR_TC), 10, 100000); /* Send the TC error message only when ISR_TC is not set. */ if (ret) dev_err(port->dev, "Transmission is not complete\n"); /* Stop serial port and reset value */ writel_relaxed(0, port->membase + ofs->cr1); /* flush RX & TX FIFO */ if (ofs->rqr != UNDEF_REG) writel_relaxed(USART_RQR_TXFRQ | USART_RQR_RXFRQ, port->membase + ofs->rqr); cr1 = USART_CR1_TE | USART_CR1_RE; if (stm32_port->fifoen) cr1 |= USART_CR1_FIFOEN; cr2 = stm32_port->swap ? USART_CR2_SWAP : 0; /* Tx and RX FIFO configuration */ cr3 = readl_relaxed(port->membase + ofs->cr3); cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTIE; if (stm32_port->fifoen) { if (stm32_port->txftcfg >= 0) cr3 |= stm32_port->txftcfg << USART_CR3_TXFTCFG_SHIFT; if (stm32_port->rxftcfg >= 0) cr3 |= stm32_port->rxftcfg << USART_CR3_RXFTCFG_SHIFT; } if (cflag & CSTOPB) cr2 |= USART_CR2_STOP_2B; bits = tty_get_char_size(cflag); stm32_port->rdr_mask = (BIT(bits) - 1); if (cflag & PARENB) { bits++; cr1 |= USART_CR1_PCE; } /* * Word length configuration: * CS8 + parity, 9 bits word aka [M1:M0] = 0b01 * CS7 or (CS6 + parity), 7 bits word aka [M1:M0] = 0b10 * CS8 or (CS7 + parity), 8 bits word aka [M1:M0] = 0b00 * M0 and M1 already cleared by cr1 initialization. */ if (bits == 9) { cr1 |= USART_CR1_M0; } else if ((bits == 7) && cfg->has_7bits_data) { cr1 |= USART_CR1_M1; } else if (bits != 8) { dev_dbg(port->dev, "Unsupported data bits config: %u bits\n" , bits); cflag &= ~CSIZE; cflag |= CS8; termios->c_cflag = cflag; bits = 8; if (cflag & PARENB) { bits++; cr1 |= USART_CR1_M0; } } if (ofs->rtor != UNDEF_REG && (stm32_port->rx_ch || (stm32_port->fifoen && stm32_port->rxftcfg >= 0))) { if (cflag & CSTOPB) bits = bits + 3; /* 1 start bit + 2 stop bits */ else bits = bits + 2; /* 1 start bit + 1 stop bit */ /* RX timeout irq to occur after last stop bit + bits */ stm32_port->cr1_irq = USART_CR1_RTOIE; writel_relaxed(bits, port->membase + ofs->rtor); cr2 |= USART_CR2_RTOEN; /* * Enable fifo threshold irq in two cases, either when there is no DMA, or when * wake up over usart, from low power until the DMA gets re-enabled by resume. */ stm32_port->cr3_irq = USART_CR3_RXFTIE; } cr1 |= stm32_port->cr1_irq; cr3 |= stm32_port->cr3_irq; if (cflag & PARODD) cr1 |= USART_CR1_PS; port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); if (cflag & CRTSCTS) { port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; cr3 |= USART_CR3_CTSE | USART_CR3_RTSE; } for (presc = 0; presc <= USART_PRESC_MAX; presc++) { uart_clk_pres = DIV_ROUND_CLOSEST(uart_clk, stm32_usart_presc_val[presc]); usartdiv = DIV_ROUND_CLOSEST(uart_clk_pres, baud); /* * The USART supports 16 or 8 times oversampling. * By default we prefer 16 times oversampling, so that the receiver * has a better tolerance to clock deviations. * 8 times oversampling is only used to achieve higher speeds. */ if (usartdiv < 16) { oversampling = 8; cr1 |= USART_CR1_OVER8; stm32_usart_set_bits(port, ofs->cr1, USART_CR1_OVER8); } else { oversampling = 16; cr1 &= ~USART_CR1_OVER8; stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_OVER8); } mantissa = (usartdiv / oversampling) << USART_BRR_DIV_M_SHIFT; fraction = usartdiv % oversampling; brr = mantissa | fraction; if (FIELD_FIT(USART_BRR_MASK, brr)) { if (ofs->presc != UNDEF_REG) { port->uartclk = uart_clk_pres; writel_relaxed(presc, port->membase + ofs->presc); } else if (presc) { /* We need a prescaler but we don't have it (STM32F4, STM32F7) */ dev_err(port->dev, "unable to set baudrate, input clock is too high"); } break; } else if (presc == USART_PRESC_MAX) { /* Even with prescaler and brr at max value we can't set baudrate */ dev_err(port->dev, "unable to set baudrate, input clock is too high"); break; } } writel_relaxed(brr, port->membase + ofs->brr); uart_update_timeout(port, cflag, baud); port->read_status_mask = USART_SR_ORE; if (termios->c_iflag & INPCK) port->read_status_mask |= USART_SR_PE | USART_SR_FE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= USART_SR_FE; /* Characters to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask = USART_SR_PE | USART_SR_FE; if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= USART_SR_FE; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= USART_SR_ORE; } /* Ignore all characters if CREAD is not set */ if ((termios->c_cflag & CREAD) == 0) port->ignore_status_mask |= USART_SR_DUMMY_RX; if (stm32_port->rx_ch) { /* * Setup DMA to collect only valid data and enable error irqs. * This also enables break reception when using DMA. */ cr1 |= USART_CR1_PEIE; cr3 |= USART_CR3_EIE; cr3 |= USART_CR3_DMAR; cr3 |= USART_CR3_DDRE; } if (stm32_port->tx_ch) cr3 |= USART_CR3_DMAT; if (rs485conf->flags & SER_RS485_ENABLED) { stm32_usart_config_reg_rs485(&cr1, &cr3, rs485conf->delay_rts_before_send, rs485conf->delay_rts_after_send, baud); if (rs485conf->flags & SER_RS485_RTS_ON_SEND) { cr3 &= ~USART_CR3_DEP; rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND; } else { cr3 |= USART_CR3_DEP; rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; } } else { cr3 &= ~(USART_CR3_DEM | USART_CR3_DEP); cr1 &= ~(USART_CR1_DEDT_MASK | USART_CR1_DEAT_MASK); } /* Configure wake up from low power on start bit detection */ if (stm32_port->wakeup_src) { cr3 &= ~USART_CR3_WUS_MASK; cr3 |= USART_CR3_WUS_START_BIT; } writel_relaxed(cr3, port->membase + ofs->cr3); writel_relaxed(cr2, port->membase + ofs->cr2); writel_relaxed(cr1, port->membase + ofs->cr1); stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); uart_port_unlock_irqrestore(port, flags); /* Handle modem control interrupts */ if (UART_ENABLE_MS(port, termios->c_cflag)) stm32_usart_enable_ms(port); else stm32_usart_disable_ms(port); } static const char *stm32_usart_type(struct uart_port *port) { return (port->type == PORT_STM32) ? DRIVER_NAME : NULL; } static void stm32_usart_release_port(struct uart_port *port) { } static int stm32_usart_request_port(struct uart_port *port) { return 0; } static void stm32_usart_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) port->type = PORT_STM32; } static int stm32_usart_verify_port(struct uart_port *port, struct serial_struct *ser) { /* No user changeable parameters */ return -EINVAL; } static void stm32_usart_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct stm32_port *stm32port = container_of(port, struct stm32_port, port); const struct stm32_usart_offsets *ofs = &stm32port->info->ofs; const struct stm32_usart_config *cfg = &stm32port->info->cfg; unsigned long flags; switch (state) { case UART_PM_STATE_ON: pm_runtime_get_sync(port->dev); break; case UART_PM_STATE_OFF: uart_port_lock_irqsave(port, &flags); stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); uart_port_unlock_irqrestore(port, flags); pm_runtime_put_sync(port->dev); break; } } #if defined(CONFIG_CONSOLE_POLL) /* Callbacks for characters polling in debug context (i.e. KGDB). */ static int stm32_usart_poll_init(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); return clk_prepare_enable(stm32_port->clk); } static int stm32_usart_poll_get_char(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_RXNE)) return NO_POLL_CHAR; return readl_relaxed(port->membase + ofs->rdr) & stm32_port->rdr_mask; } static void stm32_usart_poll_put_char(struct uart_port *port, unsigned char ch) { stm32_usart_console_putchar(port, ch); } #endif /* CONFIG_CONSOLE_POLL */ static const struct uart_ops stm32_uart_ops = { .tx_empty = stm32_usart_tx_empty, .set_mctrl = stm32_usart_set_mctrl, .get_mctrl = stm32_usart_get_mctrl, .stop_tx = stm32_usart_stop_tx, .start_tx = stm32_usart_start_tx, .throttle = stm32_usart_throttle, .unthrottle = stm32_usart_unthrottle, .stop_rx = stm32_usart_stop_rx, .enable_ms = stm32_usart_enable_ms, .break_ctl = stm32_usart_break_ctl, .startup = stm32_usart_startup, .shutdown = stm32_usart_shutdown, .flush_buffer = stm32_usart_flush_buffer, .set_termios = stm32_usart_set_termios, .pm = stm32_usart_pm, .type = stm32_usart_type, .release_port = stm32_usart_release_port, .request_port = stm32_usart_request_port, .config_port = stm32_usart_config_port, .verify_port = stm32_usart_verify_port, #if defined(CONFIG_CONSOLE_POLL) .poll_init = stm32_usart_poll_init, .poll_get_char = stm32_usart_poll_get_char, .poll_put_char = stm32_usart_poll_put_char, #endif /* CONFIG_CONSOLE_POLL */ }; struct stm32_usart_thresh_ratio { int mul; int div; }; static const struct stm32_usart_thresh_ratio stm32h7_usart_fifo_thresh_cfg[] = { {1, 8}, {1, 4}, {1, 2}, {3, 4}, {7, 8}, {1, 1} }; static int stm32_usart_get_thresh_value(u32 fifo_size, int index) { return fifo_size * stm32h7_usart_fifo_thresh_cfg[index].mul / stm32h7_usart_fifo_thresh_cfg[index].div; } static int stm32_usart_get_ftcfg(struct platform_device *pdev, struct stm32_port *stm32port, const char *p, int *ftcfg) { const struct stm32_usart_offsets *ofs = &stm32port->info->ofs; u32 bytes, i, cfg8; int fifo_size; if (WARN_ON(ofs->hwcfgr1 == UNDEF_REG)) return 1; cfg8 = FIELD_GET(USART_HWCFGR1_CFG8, readl_relaxed(stm32port->port.membase + ofs->hwcfgr1)); /* On STM32H7, hwcfgr is not present, so returned value will be 0 */ fifo_size = cfg8 ? 1 << cfg8 : STM32H7_USART_FIFO_SIZE; /* DT option to get RX & TX FIFO threshold (default to half fifo size) */ if (of_property_read_u32(pdev->dev.of_node, p, &bytes)) bytes = fifo_size / 2; if (bytes < stm32_usart_get_thresh_value(fifo_size, 0)) { *ftcfg = -EINVAL; return fifo_size; } for (i = 0; i < ARRAY_SIZE(stm32h7_usart_fifo_thresh_cfg); i++) { if (stm32_usart_get_thresh_value(fifo_size, i) >= bytes) break; } if (i >= ARRAY_SIZE(stm32h7_usart_fifo_thresh_cfg)) i = ARRAY_SIZE(stm32h7_usart_fifo_thresh_cfg) - 1; dev_dbg(&pdev->dev, "%s set to %d/%d bytes\n", p, stm32_usart_get_thresh_value(fifo_size, i), fifo_size); *ftcfg = i; return fifo_size; } static void stm32_usart_deinit_port(struct stm32_port *stm32port) { clk_disable_unprepare(stm32port->clk); } static const struct serial_rs485 stm32_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 stm32_usart_init_port(struct stm32_port *stm32port, struct platform_device *pdev) { struct uart_port *port = &stm32port->port; struct resource *res; int ret, irq; irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; port->iotype = UPIO_MEM; port->flags = UPF_BOOT_AUTOCONF; port->ops = &stm32_uart_ops; port->dev = &pdev->dev; port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_STM32_CONSOLE); port->irq = irq; port->rs485_config = stm32_usart_config_rs485; port->rs485_supported = stm32_rs485_supported; ret = stm32_usart_init_rs485(port, pdev); if (ret) return ret; stm32port->wakeup_src = stm32port->info->cfg.has_wakeup && of_property_read_bool(pdev->dev.of_node, "wakeup-source"); stm32port->swap = stm32port->info->cfg.has_swap && of_property_read_bool(pdev->dev.of_node, "rx-tx-swap"); port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res); if (IS_ERR(port->membase)) return PTR_ERR(port->membase); port->mapbase = res->start; spin_lock_init(&port->lock); stm32port->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(stm32port->clk)) return PTR_ERR(stm32port->clk); /* Ensure that clk rate is correct by enabling the clk */ ret = clk_prepare_enable(stm32port->clk); if (ret) return ret; stm32port->port.uartclk = clk_get_rate(stm32port->clk); if (!stm32port->port.uartclk) { ret = -EINVAL; goto err_clk; } stm32port->fifoen = stm32port->info->cfg.has_fifo; if (stm32port->fifoen) { stm32_usart_get_ftcfg(pdev, stm32port, "rx-threshold", &stm32port->rxftcfg); port->fifosize = stm32_usart_get_ftcfg(pdev, stm32port, "tx-threshold", &stm32port->txftcfg); } else { port->fifosize = 1; } stm32port->gpios = mctrl_gpio_init(&stm32port->port, 0); if (IS_ERR(stm32port->gpios)) { ret = PTR_ERR(stm32port->gpios); goto err_clk; } /* * Both CTS/RTS gpios and "st,hw-flow-ctrl" (deprecated) or "uart-has-rtscts" * properties should not be specified. */ if (stm32port->hw_flow_control) { if (mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_CTS) || mctrl_gpio_to_gpiod(stm32port->gpios, UART_GPIO_RTS)) { dev_err(&pdev->dev, "Conflicting RTS/CTS config\n"); ret = -EINVAL; goto err_clk; } } return ret; err_clk: clk_disable_unprepare(stm32port->clk); return ret; } static struct stm32_port *stm32_usart_of_get_port(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; int id; if (!np) return NULL; id = of_alias_get_id(np, "serial"); if (id < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", id); return NULL; } if (WARN_ON(id >= STM32_MAX_PORTS)) return NULL; stm32_ports[id].hw_flow_control = of_property_read_bool (np, "st,hw-flow-ctrl") /*deprecated*/ || of_property_read_bool (np, "uart-has-rtscts"); stm32_ports[id].port.line = id; stm32_ports[id].cr1_irq = USART_CR1_RXNEIE; stm32_ports[id].cr3_irq = 0; stm32_ports[id].last_res = RX_BUF_L; return &stm32_ports[id]; } #ifdef CONFIG_OF static const struct of_device_id stm32_match[] = { { .compatible = "st,stm32-uart", .data = &stm32f4_info}, { .compatible = "st,stm32f7-uart", .data = &stm32f7_info}, { .compatible = "st,stm32h7-uart", .data = &stm32h7_info}, {}, }; MODULE_DEVICE_TABLE(of, stm32_match); #endif static void stm32_usart_of_dma_rx_remove(struct stm32_port *stm32port, struct platform_device *pdev) { if (stm32port->rx_buf) dma_free_coherent(&pdev->dev, RX_BUF_L, stm32port->rx_buf, stm32port->rx_dma_buf); } static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port, struct platform_device *pdev) { const struct stm32_usart_offsets *ofs = &stm32port->info->ofs; struct uart_port *port = &stm32port->port; struct device *dev = &pdev->dev; struct dma_slave_config config; int ret; stm32port->rx_buf = dma_alloc_coherent(dev, RX_BUF_L, &stm32port->rx_dma_buf, GFP_KERNEL); if (!stm32port->rx_buf) return -ENOMEM; /* Configure DMA channel */ memset(&config, 0, sizeof(config)); config.src_addr = port->mapbase + ofs->rdr; config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; ret = dmaengine_slave_config(stm32port->rx_ch, &config); if (ret < 0) { dev_err(dev, "rx dma channel config failed\n"); stm32_usart_of_dma_rx_remove(stm32port, pdev); return ret; } return 0; } static void stm32_usart_of_dma_tx_remove(struct stm32_port *stm32port, struct platform_device *pdev) { if (stm32port->tx_buf) dma_free_coherent(&pdev->dev, TX_BUF_L, stm32port->tx_buf, stm32port->tx_dma_buf); } static int stm32_usart_of_dma_tx_probe(struct stm32_port *stm32port, struct platform_device *pdev) { const struct stm32_usart_offsets *ofs = &stm32port->info->ofs; struct uart_port *port = &stm32port->port; struct device *dev = &pdev->dev; struct dma_slave_config config; int ret; stm32port->tx_buf = dma_alloc_coherent(dev, TX_BUF_L, &stm32port->tx_dma_buf, GFP_KERNEL); if (!stm32port->tx_buf) return -ENOMEM; /* Configure DMA channel */ memset(&config, 0, sizeof(config)); config.dst_addr = port->mapbase + ofs->tdr; config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; ret = dmaengine_slave_config(stm32port->tx_ch, &config); if (ret < 0) { dev_err(dev, "tx dma channel config failed\n"); stm32_usart_of_dma_tx_remove(stm32port, pdev); return ret; } return 0; } static int stm32_usart_serial_probe(struct platform_device *pdev) { struct stm32_port *stm32port; int ret; stm32port = stm32_usart_of_get_port(pdev); if (!stm32port) return -ENODEV; stm32port->info = of_device_get_match_data(&pdev->dev); if (!stm32port->info) return -EINVAL; stm32port->rx_ch = dma_request_chan(&pdev->dev, "rx"); if (PTR_ERR(stm32port->rx_ch) == -EPROBE_DEFER) return -EPROBE_DEFER; /* Fall back in interrupt mode for any non-deferral error */ if (IS_ERR(stm32port->rx_ch)) stm32port->rx_ch = NULL; stm32port->tx_ch = dma_request_chan(&pdev->dev, "tx"); if (PTR_ERR(stm32port->tx_ch) == -EPROBE_DEFER) { ret = -EPROBE_DEFER; goto err_dma_rx; } /* Fall back in interrupt mode for any non-deferral error */ if (IS_ERR(stm32port->tx_ch)) stm32port->tx_ch = NULL; ret = stm32_usart_init_port(stm32port, pdev); if (ret) goto err_dma_tx; if (stm32port->wakeup_src) { device_set_wakeup_capable(&pdev->dev, true); ret = dev_pm_set_wake_irq(&pdev->dev, stm32port->port.irq); if (ret) goto err_deinit_port; } if (stm32port->rx_ch && stm32_usart_of_dma_rx_probe(stm32port, pdev)) { /* Fall back in interrupt mode */ dma_release_channel(stm32port->rx_ch); stm32port->rx_ch = NULL; } if (stm32port->tx_ch && stm32_usart_of_dma_tx_probe(stm32port, pdev)) { /* Fall back in interrupt mode */ dma_release_channel(stm32port->tx_ch); stm32port->tx_ch = NULL; } if (!stm32port->rx_ch) dev_info(&pdev->dev, "interrupt mode for rx (no dma)\n"); if (!stm32port->tx_ch) dev_info(&pdev->dev, "interrupt mode for tx (no dma)\n"); platform_set_drvdata(pdev, &stm32port->port); pm_runtime_get_noresume(&pdev->dev); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port); if (ret) goto err_port; pm_runtime_put_sync(&pdev->dev); return 0; err_port: pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_put_noidle(&pdev->dev); if (stm32port->tx_ch) stm32_usart_of_dma_tx_remove(stm32port, pdev); if (stm32port->rx_ch) stm32_usart_of_dma_rx_remove(stm32port, pdev); if (stm32port->wakeup_src) dev_pm_clear_wake_irq(&pdev->dev); err_deinit_port: if (stm32port->wakeup_src) device_set_wakeup_capable(&pdev->dev, false); stm32_usart_deinit_port(stm32port); err_dma_tx: if (stm32port->tx_ch) dma_release_channel(stm32port->tx_ch); err_dma_rx: if (stm32port->rx_ch) dma_release_channel(stm32port->rx_ch); return ret; } static void stm32_usart_serial_remove(struct platform_device *pdev) { struct uart_port *port = platform_get_drvdata(pdev); struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; u32 cr3; pm_runtime_get_sync(&pdev->dev); uart_remove_one_port(&stm32_usart_driver, port); pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_put_noidle(&pdev->dev); stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_PEIE); if (stm32_port->tx_ch) { stm32_usart_of_dma_tx_remove(stm32_port, pdev); dma_release_channel(stm32_port->tx_ch); } if (stm32_port->rx_ch) { stm32_usart_of_dma_rx_remove(stm32_port, pdev); dma_release_channel(stm32_port->rx_ch); } cr3 = readl_relaxed(port->membase + ofs->cr3); cr3 &= ~USART_CR3_EIE; cr3 &= ~USART_CR3_DMAR; cr3 &= ~USART_CR3_DMAT; cr3 &= ~USART_CR3_DDRE; writel_relaxed(cr3, port->membase + ofs->cr3); if (stm32_port->wakeup_src) { dev_pm_clear_wake_irq(&pdev->dev); device_init_wakeup(&pdev->dev, false); } stm32_usart_deinit_port(stm32_port); } static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; u32 isr; int ret; ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr, isr, (isr & USART_SR_TXE), 100, STM32_USART_TIMEOUT_USEC); if (ret != 0) { dev_err(port->dev, "Error while sending data in UART TX : %d\n", ret); return; } writel_relaxed(ch, port->membase + ofs->tdr); } #ifdef CONFIG_SERIAL_STM32_CONSOLE static void stm32_usart_console_write(struct console *co, const char *s, unsigned int cnt) { struct uart_port *port = &stm32_ports[co->index].port; struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; const struct stm32_usart_config *cfg = &stm32_port->info->cfg; unsigned long flags; u32 old_cr1, new_cr1; int locked = 1; if (oops_in_progress) locked = uart_port_trylock_irqsave(port, &flags); else uart_port_lock_irqsave(port, &flags); /* Save and disable interrupts, enable the transmitter */ old_cr1 = readl_relaxed(port->membase + ofs->cr1); new_cr1 = old_cr1 & ~USART_CR1_IE_MASK; new_cr1 |= USART_CR1_TE | BIT(cfg->uart_enable_bit); writel_relaxed(new_cr1, port->membase + ofs->cr1); uart_console_write(port, s, cnt, stm32_usart_console_putchar); /* Restore interrupt state */ writel_relaxed(old_cr1, port->membase + ofs->cr1); if (locked) uart_port_unlock_irqrestore(port, flags); } static int stm32_usart_console_setup(struct console *co, char *options) { struct stm32_port *stm32port; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; if (co->index >= STM32_MAX_PORTS) return -ENODEV; stm32port = &stm32_ports[co->index]; /* * This driver does not support early console initialization * (use ARM early printk support instead), so we only expect * this to be called during the uart port registration when the * driver gets probed and the port should be mapped at that point. */ if (stm32port->port.mapbase == 0 || !stm32port->port.membase) return -ENXIO; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); return uart_set_options(&stm32port->port, co, baud, parity, bits, flow); } static struct console stm32_console = { .name = STM32_SERIAL_NAME, .device = uart_console_device, .write = stm32_usart_console_write, .setup = stm32_usart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &stm32_usart_driver, }; #define STM32_SERIAL_CONSOLE (&stm32_console) #else #define STM32_SERIAL_CONSOLE NULL #endif /* CONFIG_SERIAL_STM32_CONSOLE */ #ifdef CONFIG_SERIAL_EARLYCON static void early_stm32_usart_console_putchar(struct uart_port *port, unsigned char ch) { struct stm32_usart_info *info = port->private_data; while (!(readl_relaxed(port->membase + info->ofs.isr) & USART_SR_TXE)) cpu_relax(); writel_relaxed(ch, port->membase + info->ofs.tdr); } static void early_stm32_serial_write(struct console *console, const char *s, unsigned int count) { struct earlycon_device *device = console->data; struct uart_port *port = &device->port; uart_console_write(port, s, count, early_stm32_usart_console_putchar); } static int __init early_stm32_h7_serial_setup(struct earlycon_device *device, const char *options) { if (!(device->port.membase || device->port.iobase)) return -ENODEV; device->port.private_data = &stm32h7_info; device->con->write = early_stm32_serial_write; return 0; } static int __init early_stm32_f7_serial_setup(struct earlycon_device *device, const char *options) { if (!(device->port.membase || device->port.iobase)) return -ENODEV; device->port.private_data = &stm32f7_info; device->con->write = early_stm32_serial_write; return 0; } static int __init early_stm32_f4_serial_setup(struct earlycon_device *device, const char *options) { if (!(device->port.membase || device->port.iobase)) return -ENODEV; device->port.private_data = &stm32f4_info; device->con->write = early_stm32_serial_write; return 0; } OF_EARLYCON_DECLARE(stm32, "st,stm32h7-uart", early_stm32_h7_serial_setup); OF_EARLYCON_DECLARE(stm32, "st,stm32f7-uart", early_stm32_f7_serial_setup); OF_EARLYCON_DECLARE(stm32, "st,stm32-uart", early_stm32_f4_serial_setup); #endif /* CONFIG_SERIAL_EARLYCON */ static struct uart_driver stm32_usart_driver = { .driver_name = DRIVER_NAME, .dev_name = STM32_SERIAL_NAME, .major = 0, .minor = 0, .nr = STM32_MAX_PORTS, .cons = STM32_SERIAL_CONSOLE, }; static int __maybe_unused stm32_usart_serial_en_wakeup(struct uart_port *port, bool enable) { struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct tty_port *tport = &port->state->port; int ret; unsigned int size = 0; unsigned long flags; if (!stm32_port->wakeup_src || !tty_port_initialized(tport)) return 0; /* * Enable low-power wake-up and wake-up irq if argument is set to * "enable", disable low-power wake-up and wake-up irq otherwise */ if (enable) { stm32_usart_set_bits(port, ofs->cr1, USART_CR1_UESM); stm32_usart_set_bits(port, ofs->cr3, USART_CR3_WUFIE); mctrl_gpio_enable_irq_wake(stm32_port->gpios); /* * When DMA is used for reception, it must be disabled before * entering low-power mode and re-enabled when exiting from * low-power mode. */ if (stm32_port->rx_ch) { uart_port_lock_irqsave(port, &flags); /* Poll data from DMA RX buffer if any */ if (!stm32_usart_rx_dma_pause(stm32_port)) size += stm32_usart_receive_chars(port, true); stm32_usart_rx_dma_terminate(stm32_port); uart_unlock_and_check_sysrq_irqrestore(port, flags); if (size) tty_flip_buffer_push(tport); } /* Poll data from RX FIFO if any */ stm32_usart_receive_chars(port, false); } else { if (stm32_port->rx_ch) { ret = stm32_usart_rx_dma_start_or_resume(port); if (ret) return ret; } mctrl_gpio_disable_irq_wake(stm32_port->gpios); stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_UESM); stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE); } return 0; } static int __maybe_unused stm32_usart_serial_suspend(struct device *dev) { struct uart_port *port = dev_get_drvdata(dev); int ret; uart_suspend_port(&stm32_usart_driver, port); if (device_may_wakeup(dev) || device_wakeup_path(dev)) { ret = stm32_usart_serial_en_wakeup(port, true); if (ret) return ret; } /* * When "no_console_suspend" is enabled, keep the pinctrl default state * and rely on bootloader stage to restore this state upon resume. * Otherwise, apply the idle or sleep states depending on wakeup * capabilities. */ if (console_suspend_enabled || !uart_console(port)) { if (device_may_wakeup(dev) || device_wakeup_path(dev)) pinctrl_pm_select_idle_state(dev); else pinctrl_pm_select_sleep_state(dev); } return 0; } static int __maybe_unused stm32_usart_serial_resume(struct device *dev) { struct uart_port *port = dev_get_drvdata(dev); int ret; pinctrl_pm_select_default_state(dev); if (device_may_wakeup(dev) || device_wakeup_path(dev)) { ret = stm32_usart_serial_en_wakeup(port, false); if (ret) return ret; } return uart_resume_port(&stm32_usart_driver, port); } static int __maybe_unused stm32_usart_runtime_suspend(struct device *dev) { struct uart_port *port = dev_get_drvdata(dev); struct stm32_port *stm32port = container_of(port, struct stm32_port, port); clk_disable_unprepare(stm32port->clk); return 0; } static int __maybe_unused stm32_usart_runtime_resume(struct device *dev) { struct uart_port *port = dev_get_drvdata(dev); struct stm32_port *stm32port = container_of(port, struct stm32_port, port); return clk_prepare_enable(stm32port->clk); } static const struct dev_pm_ops stm32_serial_pm_ops = { SET_RUNTIME_PM_OPS(stm32_usart_runtime_suspend, stm32_usart_runtime_resume, NULL) SET_SYSTEM_SLEEP_PM_OPS(stm32_usart_serial_suspend, stm32_usart_serial_resume) }; static struct platform_driver stm32_serial_driver = { .probe = stm32_usart_serial_probe, .remove_new = stm32_usart_serial_remove, .driver = { .name = DRIVER_NAME, .pm = &stm32_serial_pm_ops, .of_match_table = of_match_ptr(stm32_match), }, }; static int __init stm32_usart_init(void) { static char banner[] __initdata = "STM32 USART driver initialized"; int ret; pr_info("%s\n", banner); ret = uart_register_driver(&stm32_usart_driver); if (ret) return ret; ret = platform_driver_register(&stm32_serial_driver); if (ret) uart_unregister_driver(&stm32_usart_driver); return ret; } static void __exit stm32_usart_exit(void) { platform_driver_unregister(&stm32_serial_driver); uart_unregister_driver(&stm32_usart_driver); } module_init(stm32_usart_init); module_exit(stm32_usart_exit); MODULE_ALIAS("platform:" DRIVER_NAME); MODULE_DESCRIPTION("STMicroelectronics STM32 serial port driver"); MODULE_LICENSE("GPL v2");
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