| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Wolfram Sang | 2044 | 38.16% | 79 | 71.82% |
| Kuninori Morimoto | 1634 | 30.50% | 4 | 3.64% |
| Niklas Söderlund | 1043 | 19.47% | 2 | 1.82% |
| Ulrich Hecht | 248 | 4.63% | 2 | 1.82% |
| Guennadi Liakhovetski | 206 | 3.85% | 3 | 2.73% |
| Nguyen Viet Dung | 46 | 0.86% | 1 | 0.91% |
| Ben Dooks | 31 | 0.58% | 3 | 2.73% |
| Geert Uytterhoeven | 19 | 0.35% | 4 | 3.64% |
| Andy Shevchenko | 16 | 0.30% | 1 | 0.91% |
| Sergey Shtylyov | 15 | 0.28% | 1 | 0.91% |
| Simon Horman | 14 | 0.26% | 1 | 0.91% |
| Thierry Reding | 14 | 0.26% | 1 | 0.91% |
| Sergei Shtylyov | 13 | 0.24% | 3 | 2.73% |
| Eugeniu Rosca | 5 | 0.09% | 1 | 0.91% |
| Peter Rosin | 3 | 0.06% | 1 | 0.91% |
| Dejin Zheng | 3 | 0.06% | 1 | 0.91% |
| Uwe Kleine-König | 2 | 0.04% | 1 | 0.91% |
| Hiromitsu Yamasaki | 1 | 0.02% | 1 | 0.91% |
| Total | 5357 | 110 |
// SPDX-License-Identifier: GPL-2.0 /* * Driver for the Renesas R-Car I2C unit * * Copyright (C) 2014-19 Wolfram Sang <wsa@sang-engineering.com> * Copyright (C) 2011-2019 Renesas Electronics Corporation * * Copyright (C) 2012-14 Renesas Solutions Corp. * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> * * This file is based on the drivers/i2c/busses/i2c-sh7760.c * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com> */ #include <linux/bitops.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/iopoll.h> #include <linux/i2c.h> #include <linux/i2c-smbus.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/reset.h> #include <linux/slab.h> /* register offsets */ #define ICSCR 0x00 /* slave ctrl */ #define ICMCR 0x04 /* master ctrl */ #define ICSSR 0x08 /* slave status */ #define ICMSR 0x0C /* master status */ #define ICSIER 0x10 /* slave irq enable */ #define ICMIER 0x14 /* master irq enable */ #define ICCCR 0x18 /* clock dividers */ #define ICSAR 0x1C /* slave address */ #define ICMAR 0x20 /* master address */ #define ICRXTX 0x24 /* data port */ #define ICFBSCR 0x38 /* first bit setup cycle (Gen3) */ #define ICDMAER 0x3c /* DMA enable (Gen3) */ /* ICSCR */ #define SDBS BIT(3) /* slave data buffer select */ #define SIE BIT(2) /* slave interface enable */ #define GCAE BIT(1) /* general call address enable */ #define FNA BIT(0) /* forced non acknowledgment */ /* ICMCR */ #define MDBS BIT(7) /* non-fifo mode switch */ #define FSCL BIT(6) /* override SCL pin */ #define FSDA BIT(5) /* override SDA pin */ #define OBPC BIT(4) /* override pins */ #define MIE BIT(3) /* master if enable */ #define TSBE BIT(2) #define FSB BIT(1) /* force stop bit */ #define ESG BIT(0) /* enable start bit gen */ /* ICSSR (also for ICSIER) */ #define GCAR BIT(6) /* general call received */ #define STM BIT(5) /* slave transmit mode */ #define SSR BIT(4) /* stop received */ #define SDE BIT(3) /* slave data empty */ #define SDT BIT(2) /* slave data transmitted */ #define SDR BIT(1) /* slave data received */ #define SAR BIT(0) /* slave addr received */ /* ICMSR (also for ICMIE) */ #define MNR BIT(6) /* nack received */ #define MAL BIT(5) /* arbitration lost */ #define MST BIT(4) /* sent a stop */ #define MDE BIT(3) #define MDT BIT(2) #define MDR BIT(1) #define MAT BIT(0) /* slave addr xfer done */ /* ICDMAER */ #define RSDMAE BIT(3) /* DMA Slave Received Enable */ #define TSDMAE BIT(2) /* DMA Slave Transmitted Enable */ #define RMDMAE BIT(1) /* DMA Master Received Enable */ #define TMDMAE BIT(0) /* DMA Master Transmitted Enable */ /* ICFBSCR */ #define TCYC17 0x0f /* 17*Tcyc delay 1st bit between SDA and SCL */ #define RCAR_MIN_DMA_LEN 8 #define RCAR_BUS_PHASE_START (MDBS | MIE | ESG) #define RCAR_BUS_PHASE_DATA (MDBS | MIE) #define RCAR_BUS_PHASE_STOP (MDBS | MIE | FSB) #define RCAR_IRQ_SEND (MNR | MAL | MST | MAT | MDE) #define RCAR_IRQ_RECV (MNR | MAL | MST | MAT | MDR) #define RCAR_IRQ_STOP (MST) #define ID_LAST_MSG BIT(0) #define ID_REP_AFTER_RD BIT(1) #define ID_DONE BIT(2) #define ID_ARBLOST BIT(3) #define ID_NACK BIT(4) #define ID_EPROTO BIT(5) /* persistent flags */ #define ID_P_NOT_ATOMIC BIT(28) #define ID_P_HOST_NOTIFY BIT(29) #define ID_P_NO_RXDMA BIT(30) /* HW forbids RXDMA sometimes */ #define ID_P_PM_BLOCKED BIT(31) #define ID_P_MASK GENMASK(31, 28) enum rcar_i2c_type { I2C_RCAR_GEN1, I2C_RCAR_GEN2, I2C_RCAR_GEN3, }; struct rcar_i2c_priv { u32 flags; void __iomem *io; struct i2c_adapter adap; struct i2c_msg *msg; int msgs_left; struct clk *clk; wait_queue_head_t wait; int pos; u32 icccr; u8 recovery_icmcr; /* protected by adapter lock */ enum rcar_i2c_type devtype; struct i2c_client *slave; struct resource *res; struct dma_chan *dma_tx; struct dma_chan *dma_rx; struct scatterlist sg; enum dma_data_direction dma_direction; struct reset_control *rstc; int irq; struct i2c_client *host_notify_client; }; #define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent) #define rcar_i2c_is_recv(p) ((p)->msg->flags & I2C_M_RD) static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val) { writel(val, priv->io + reg); } static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg) { return readl(priv->io + reg); } static void rcar_i2c_clear_irq(struct rcar_i2c_priv *priv, u32 val) { writel(~val & 0x7f, priv->io + ICMSR); } static int rcar_i2c_get_scl(struct i2c_adapter *adap) { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); return !!(rcar_i2c_read(priv, ICMCR) & FSCL); }; static void rcar_i2c_set_scl(struct i2c_adapter *adap, int val) { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); if (val) priv->recovery_icmcr |= FSCL; else priv->recovery_icmcr &= ~FSCL; rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr); }; static void rcar_i2c_set_sda(struct i2c_adapter *adap, int val) { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); if (val) priv->recovery_icmcr |= FSDA; else priv->recovery_icmcr &= ~FSDA; rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr); }; static int rcar_i2c_get_bus_free(struct i2c_adapter *adap) { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); return !(rcar_i2c_read(priv, ICMCR) & FSDA); }; static struct i2c_bus_recovery_info rcar_i2c_bri = { .get_scl = rcar_i2c_get_scl, .set_scl = rcar_i2c_set_scl, .set_sda = rcar_i2c_set_sda, .get_bus_free = rcar_i2c_get_bus_free, .recover_bus = i2c_generic_scl_recovery, }; static void rcar_i2c_init(struct rcar_i2c_priv *priv) { /* reset master mode */ rcar_i2c_write(priv, ICMIER, 0); rcar_i2c_write(priv, ICMCR, MDBS); rcar_i2c_write(priv, ICMSR, 0); /* start clock */ rcar_i2c_write(priv, ICCCR, priv->icccr); if (priv->devtype == I2C_RCAR_GEN3) rcar_i2c_write(priv, ICFBSCR, TCYC17); } static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) { int ret; u32 val; ret = readl_poll_timeout(priv->io + ICMCR, val, !(val & FSDA), 10, priv->adap.timeout); if (ret) { /* Waiting did not help, try to recover */ priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL; ret = i2c_recover_bus(&priv->adap); } return ret; } static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv) { u32 scgd, cdf, round, ick, sum, scl, cdf_width; unsigned long rate; struct device *dev = rcar_i2c_priv_to_dev(priv); struct i2c_timings t = { .bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ, .scl_fall_ns = 35, .scl_rise_ns = 200, .scl_int_delay_ns = 50, }; /* Fall back to previously used values if not supplied */ i2c_parse_fw_timings(dev, &t, false); switch (priv->devtype) { case I2C_RCAR_GEN1: cdf_width = 2; break; case I2C_RCAR_GEN2: case I2C_RCAR_GEN3: cdf_width = 3; break; default: dev_err(dev, "device type error\n"); return -EIO; } /* * calculate SCL clock * see * ICCCR * * ick = clkp / (1 + CDF) * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick]) * * ick : I2C internal clock < 20 MHz * ticf : I2C SCL falling time * tr : I2C SCL rising time * intd : LSI internal delay * clkp : peripheral_clk * F[] : integer up-valuation */ rate = clk_get_rate(priv->clk); cdf = rate / 20000000; if (cdf >= 1U << cdf_width) { dev_err(dev, "Input clock %lu too high\n", rate); return -EIO; } ick = rate / (cdf + 1); /* * it is impossible to calculate large scale * number on u32. separate it * * F[(ticf + tr + intd) * ick] with sum = (ticf + tr + intd) * = F[sum * ick / 1000000000] * = F[(ick / 1000000) * sum / 1000] */ sum = t.scl_fall_ns + t.scl_rise_ns + t.scl_int_delay_ns; round = (ick + 500000) / 1000000 * sum; round = (round + 500) / 1000; /* * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick]) * * Calculation result (= SCL) should be less than * bus_speed for hardware safety * * We could use something along the lines of * div = ick / (bus_speed + 1) + 1; * scgd = (div - 20 - round + 7) / 8; * scl = ick / (20 + (scgd * 8) + round); * (not fully verified) but that would get pretty involved */ for (scgd = 0; scgd < 0x40; scgd++) { scl = ick / (20 + (scgd * 8) + round); if (scl <= t.bus_freq_hz) goto scgd_find; } dev_err(dev, "it is impossible to calculate best SCL\n"); return -EIO; scgd_find: dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n", scl, t.bus_freq_hz, rate, round, cdf, scgd); /* keep icccr value */ priv->icccr = scgd << cdf_width | cdf; return 0; } /* * We don't have a test case but the HW engineers say that the write order of * ICMSR and ICMCR depends on whether we issue START or REP_START. So, ICMSR * handling is outside of this function. First messages clear ICMSR before this * function, interrupt handlers clear the relevant bits after this function. */ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv) { int read = !!rcar_i2c_is_recv(priv); bool rep_start = !(priv->flags & ID_REP_AFTER_RD); priv->pos = 0; priv->flags &= ID_P_MASK; if (priv->msgs_left == 1) priv->flags |= ID_LAST_MSG; rcar_i2c_write(priv, ICMAR, i2c_8bit_addr_from_msg(priv->msg)); if (priv->flags & ID_P_NOT_ATOMIC) rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND); if (rep_start) rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); } static void rcar_i2c_first_msg(struct rcar_i2c_priv *priv, struct i2c_msg *msgs, int num) { priv->msg = msgs; priv->msgs_left = num; rcar_i2c_write(priv, ICMSR, 0); /* must be before preparing msg */ rcar_i2c_prepare_msg(priv); } static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv) { priv->msg++; priv->msgs_left--; rcar_i2c_prepare_msg(priv); /* ICMSR handling must come afterwards in the irq handler */ } static void rcar_i2c_cleanup_dma(struct rcar_i2c_priv *priv, bool terminate) { struct dma_chan *chan = priv->dma_direction == DMA_FROM_DEVICE ? priv->dma_rx : priv->dma_tx; /* only allowed from thread context! */ if (terminate) dmaengine_terminate_sync(chan); dma_unmap_single(chan->device->dev, sg_dma_address(&priv->sg), sg_dma_len(&priv->sg), priv->dma_direction); /* Gen3 can only do one RXDMA per transfer and we just completed it */ if (priv->devtype == I2C_RCAR_GEN3 && priv->dma_direction == DMA_FROM_DEVICE) priv->flags |= ID_P_NO_RXDMA; priv->dma_direction = DMA_NONE; /* Disable DMA Master Received/Transmitted, must be last! */ rcar_i2c_write(priv, ICDMAER, 0); } static void rcar_i2c_dma_callback(void *data) { struct rcar_i2c_priv *priv = data; priv->pos += sg_dma_len(&priv->sg); rcar_i2c_cleanup_dma(priv, false); } static bool rcar_i2c_dma(struct rcar_i2c_priv *priv) { struct device *dev = rcar_i2c_priv_to_dev(priv); struct i2c_msg *msg = priv->msg; bool read = msg->flags & I2C_M_RD; enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE; struct dma_chan *chan = read ? priv->dma_rx : priv->dma_tx; struct dma_async_tx_descriptor *txdesc; dma_addr_t dma_addr; dma_cookie_t cookie; unsigned char *buf; int len; /* Do various checks to see if DMA is feasible at all */ if (!(priv->flags & ID_P_NOT_ATOMIC) || IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN || !(msg->flags & I2C_M_DMA_SAFE) || (read && priv->flags & ID_P_NO_RXDMA)) return false; if (read) { /* * The last two bytes needs to be fetched using PIO in * order for the STOP phase to work. */ buf = priv->msg->buf; len = priv->msg->len - 2; } else { /* * First byte in message was sent using PIO. */ buf = priv->msg->buf + 1; len = priv->msg->len - 1; } dma_addr = dma_map_single(chan->device->dev, buf, len, dir); if (dma_mapping_error(chan->device->dev, dma_addr)) { dev_dbg(dev, "dma map failed, using PIO\n"); return false; } sg_dma_len(&priv->sg) = len; sg_dma_address(&priv->sg) = dma_addr; priv->dma_direction = dir; txdesc = dmaengine_prep_slave_sg(chan, &priv->sg, 1, read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!txdesc) { dev_dbg(dev, "dma prep slave sg failed, using PIO\n"); rcar_i2c_cleanup_dma(priv, false); return false; } txdesc->callback = rcar_i2c_dma_callback; txdesc->callback_param = priv; cookie = dmaengine_submit(txdesc); if (dma_submit_error(cookie)) { dev_dbg(dev, "submitting dma failed, using PIO\n"); rcar_i2c_cleanup_dma(priv, false); return false; } /* Enable DMA Master Received/Transmitted */ if (read) rcar_i2c_write(priv, ICDMAER, RMDMAE); else rcar_i2c_write(priv, ICDMAER, TMDMAE); dma_async_issue_pending(chan); return true; } static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) { struct i2c_msg *msg = priv->msg; u32 irqs_to_clear = MDE; /* FIXME: sometimes, unknown interrupt happened. Do nothing */ if (!(msr & MDE)) return; if (msr & MAT) irqs_to_clear |= MAT; /* Check if DMA can be enabled and take over */ if (priv->pos == 1 && rcar_i2c_dma(priv)) return; if (priv->pos < msg->len) { /* * Prepare next data to ICRXTX register. * This data will go to _SHIFT_ register. * * * * [ICRXTX] -> [SHIFT] -> [I2C bus] */ rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]); priv->pos++; } else { /* * The last data was pushed to ICRXTX on _PREV_ empty irq. * It is on _SHIFT_ register, and will sent to I2C bus. * * * * [ICRXTX] -> [SHIFT] -> [I2C bus] */ if (priv->flags & ID_LAST_MSG) /* * If current msg is the _LAST_ msg, * prepare stop condition here. * ID_DONE will be set on STOP irq. */ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); else rcar_i2c_next_msg(priv); } rcar_i2c_clear_irq(priv, irqs_to_clear); } static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) { struct i2c_msg *msg = priv->msg; bool recv_len_init = priv->pos == 0 && msg->flags & I2C_M_RECV_LEN; u32 irqs_to_clear = MDR; /* FIXME: sometimes, unknown interrupt happened. Do nothing */ if (!(msr & MDR)) return; if (msr & MAT) { irqs_to_clear |= MAT; /* * Address transfer phase finished, but no data at this point. * Try to use DMA to receive data. */ rcar_i2c_dma(priv); } else if (priv->pos < msg->len) { /* get received data */ u8 data = rcar_i2c_read(priv, ICRXTX); msg->buf[priv->pos] = data; if (recv_len_init) { if (data == 0 || data > I2C_SMBUS_BLOCK_MAX) { priv->flags |= ID_DONE | ID_EPROTO; return; } msg->len += msg->buf[0]; /* Enough data for DMA? */ if (rcar_i2c_dma(priv)) return; /* new length after RECV_LEN now properly initialized */ recv_len_init = false; } priv->pos++; } /* * If next received data is the _LAST_ and we are not waiting for a new * length because of RECV_LEN, then go to a new phase. */ if (priv->pos + 1 == msg->len && !recv_len_init) { if (priv->flags & ID_LAST_MSG) { rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); } else { rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); priv->flags |= ID_REP_AFTER_RD; } } if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG)) rcar_i2c_next_msg(priv); rcar_i2c_clear_irq(priv, irqs_to_clear); } static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv) { u32 ssr_raw, ssr_filtered; u8 value; ssr_raw = rcar_i2c_read(priv, ICSSR) & 0xff; ssr_filtered = ssr_raw & rcar_i2c_read(priv, ICSIER); if (!ssr_filtered) return false; /* address detected */ if (ssr_filtered & SAR) { /* read or write request */ if (ssr_raw & STM) { i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value); rcar_i2c_write(priv, ICRXTX, value); rcar_i2c_write(priv, ICSIER, SDE | SSR | SAR); } else { i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value); rcar_i2c_read(priv, ICRXTX); /* dummy read */ rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR); } /* Clear SSR, too, because of old STOPs to other clients than us */ rcar_i2c_write(priv, ICSSR, ~(SAR | SSR) & 0xff); } /* master sent stop */ if (ssr_filtered & SSR) { i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value); rcar_i2c_write(priv, ICSCR, SIE | SDBS); /* clear our NACK */ rcar_i2c_write(priv, ICSIER, SAR); rcar_i2c_write(priv, ICSSR, ~SSR & 0xff); } /* master wants to write to us */ if (ssr_filtered & SDR) { int ret; value = rcar_i2c_read(priv, ICRXTX); ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value); /* Send NACK in case of error */ rcar_i2c_write(priv, ICSCR, SIE | SDBS | (ret < 0 ? FNA : 0)); rcar_i2c_write(priv, ICSSR, ~SDR & 0xff); } /* master wants to read from us */ if (ssr_filtered & SDE) { i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value); rcar_i2c_write(priv, ICRXTX, value); rcar_i2c_write(priv, ICSSR, ~SDE & 0xff); } return true; } /* * This driver has a lock-free design because there are IP cores (at least * R-Car Gen2) which have an inherent race condition in their hardware design. * There, we need to switch to RCAR_BUS_PHASE_DATA as soon as possible after * the interrupt was generated, otherwise an unwanted repeated message gets * generated. It turned out that taking a spinlock at the beginning of the ISR * was already causing repeated messages. Thus, this driver was converted to * the now lockless behaviour. Please keep this in mind when hacking the driver. * R-Car Gen3 seems to have this fixed but earlier versions than R-Car Gen2 are * likely affected. Therefore, we have different interrupt handler entries. */ static irqreturn_t rcar_i2c_irq(int irq, struct rcar_i2c_priv *priv, u32 msr) { if (!msr) { if (rcar_i2c_slave_irq(priv)) return IRQ_HANDLED; return IRQ_NONE; } /* Arbitration lost */ if (msr & MAL) { priv->flags |= ID_DONE | ID_ARBLOST; goto out; } /* Nack */ if (msr & MNR) { /* HW automatically sends STOP after received NACK */ if (priv->flags & ID_P_NOT_ATOMIC) rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP); priv->flags |= ID_NACK; goto out; } /* Stop */ if (msr & MST) { priv->msgs_left--; /* The last message also made it */ priv->flags |= ID_DONE; goto out; } if (rcar_i2c_is_recv(priv)) rcar_i2c_irq_recv(priv, msr); else rcar_i2c_irq_send(priv, msr); out: if (priv->flags & ID_DONE) { rcar_i2c_write(priv, ICMIER, 0); rcar_i2c_write(priv, ICMSR, 0); if (priv->flags & ID_P_NOT_ATOMIC) wake_up(&priv->wait); } return IRQ_HANDLED; } static irqreturn_t rcar_i2c_gen2_irq(int irq, void *ptr) { struct rcar_i2c_priv *priv = ptr; u32 msr; /* Clear START or STOP immediately, except for REPSTART after read */ if (likely(!(priv->flags & ID_REP_AFTER_RD))) rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); /* Only handle interrupts that are currently enabled */ msr = rcar_i2c_read(priv, ICMSR); if (priv->flags & ID_P_NOT_ATOMIC) msr &= rcar_i2c_read(priv, ICMIER); return rcar_i2c_irq(irq, priv, msr); } static irqreturn_t rcar_i2c_gen3_irq(int irq, void *ptr) { struct rcar_i2c_priv *priv = ptr; u32 msr; /* Only handle interrupts that are currently enabled */ msr = rcar_i2c_read(priv, ICMSR); if (priv->flags & ID_P_NOT_ATOMIC) msr &= rcar_i2c_read(priv, ICMIER); /* * Clear START or STOP immediately, except for REPSTART after read or * if a spurious interrupt was detected. */ if (likely(!(priv->flags & ID_REP_AFTER_RD) && msr)) rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); return rcar_i2c_irq(irq, priv, msr); } static struct dma_chan *rcar_i2c_request_dma_chan(struct device *dev, enum dma_transfer_direction dir, dma_addr_t port_addr) { struct dma_chan *chan; struct dma_slave_config cfg; char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx"; int ret; chan = dma_request_chan(dev, chan_name); if (IS_ERR(chan)) { dev_dbg(dev, "request_channel failed for %s (%ld)\n", chan_name, PTR_ERR(chan)); return chan; } memset(&cfg, 0, sizeof(cfg)); cfg.direction = dir; if (dir == DMA_MEM_TO_DEV) { cfg.dst_addr = port_addr; cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; } else { cfg.src_addr = port_addr; cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; } ret = dmaengine_slave_config(chan, &cfg); if (ret) { dev_dbg(dev, "slave_config failed for %s (%d)\n", chan_name, ret); dma_release_channel(chan); return ERR_PTR(ret); } dev_dbg(dev, "got DMA channel for %s\n", chan_name); return chan; } static void rcar_i2c_request_dma(struct rcar_i2c_priv *priv, struct i2c_msg *msg) { struct device *dev = rcar_i2c_priv_to_dev(priv); bool read; struct dma_chan *chan; enum dma_transfer_direction dir; read = msg->flags & I2C_M_RD; chan = read ? priv->dma_rx : priv->dma_tx; if (PTR_ERR(chan) != -EPROBE_DEFER) return; dir = read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV; chan = rcar_i2c_request_dma_chan(dev, dir, priv->res->start + ICRXTX); if (read) priv->dma_rx = chan; else priv->dma_tx = chan; } static void rcar_i2c_release_dma(struct rcar_i2c_priv *priv) { if (!IS_ERR(priv->dma_tx)) { dma_release_channel(priv->dma_tx); priv->dma_tx = ERR_PTR(-EPROBE_DEFER); } if (!IS_ERR(priv->dma_rx)) { dma_release_channel(priv->dma_rx); priv->dma_rx = ERR_PTR(-EPROBE_DEFER); } } /* I2C is a special case, we need to poll the status of a reset */ static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv) { int ret; ret = reset_control_reset(priv->rstc); if (ret) return ret; return read_poll_timeout_atomic(reset_control_status, ret, ret == 0, 1, 100, false, priv->rstc); } static int rcar_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); struct device *dev = rcar_i2c_priv_to_dev(priv); int i, ret; long time_left; priv->flags |= ID_P_NOT_ATOMIC; pm_runtime_get_sync(dev); /* Check bus state before init otherwise bus busy info will be lost */ ret = rcar_i2c_bus_barrier(priv); if (ret < 0) goto out; /* Gen3 needs a reset before allowing RXDMA once */ if (priv->devtype == I2C_RCAR_GEN3) { priv->flags |= ID_P_NO_RXDMA; if (!IS_ERR(priv->rstc)) { ret = rcar_i2c_do_reset(priv); if (ret == 0) priv->flags &= ~ID_P_NO_RXDMA; } } rcar_i2c_init(priv); for (i = 0; i < num; i++) rcar_i2c_request_dma(priv, msgs + i); rcar_i2c_first_msg(priv, msgs, num); time_left = wait_event_timeout(priv->wait, priv->flags & ID_DONE, num * adap->timeout); /* cleanup DMA if it couldn't complete properly due to an error */ if (priv->dma_direction != DMA_NONE) rcar_i2c_cleanup_dma(priv, true); if (!time_left) { rcar_i2c_init(priv); ret = -ETIMEDOUT; } else if (priv->flags & ID_NACK) { ret = -ENXIO; } else if (priv->flags & ID_ARBLOST) { ret = -EAGAIN; } else if (priv->flags & ID_EPROTO) { ret = -EPROTO; } else { ret = num - priv->msgs_left; /* The number of transfer */ } out: pm_runtime_put(dev); if (ret < 0 && ret != -ENXIO) dev_err(dev, "error %d : %x\n", ret, priv->flags); return ret; } static int rcar_i2c_master_xfer_atomic(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); struct device *dev = rcar_i2c_priv_to_dev(priv); unsigned long j; bool time_left; int ret; priv->flags &= ~ID_P_NOT_ATOMIC; pm_runtime_get_sync(dev); /* Check bus state before init otherwise bus busy info will be lost */ ret = rcar_i2c_bus_barrier(priv); if (ret < 0) goto out; rcar_i2c_init(priv); rcar_i2c_first_msg(priv, msgs, num); j = jiffies + num * adap->timeout; do { u32 msr = rcar_i2c_read(priv, ICMSR); msr &= (rcar_i2c_is_recv(priv) ? RCAR_IRQ_RECV : RCAR_IRQ_SEND) | RCAR_IRQ_STOP; if (msr) { if (priv->devtype < I2C_RCAR_GEN3) rcar_i2c_gen2_irq(0, priv); else rcar_i2c_gen3_irq(0, priv); } time_left = time_before_eq(jiffies, j); } while (!(priv->flags & ID_DONE) && time_left); if (!time_left) { rcar_i2c_init(priv); ret = -ETIMEDOUT; } else if (priv->flags & ID_NACK) { ret = -ENXIO; } else if (priv->flags & ID_ARBLOST) { ret = -EAGAIN; } else if (priv->flags & ID_EPROTO) { ret = -EPROTO; } else { ret = num - priv->msgs_left; /* The number of transfer */ } out: pm_runtime_put(dev); if (ret < 0 && ret != -ENXIO) dev_err(dev, "error %d : %x\n", ret, priv->flags); return ret; } static int rcar_reg_slave(struct i2c_client *slave) { struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter); if (priv->slave) return -EBUSY; if (slave->flags & I2C_CLIENT_TEN) return -EAFNOSUPPORT; /* Keep device active for slave address detection logic */ pm_runtime_get_sync(rcar_i2c_priv_to_dev(priv)); priv->slave = slave; rcar_i2c_write(priv, ICSAR, slave->addr); rcar_i2c_write(priv, ICSSR, 0); rcar_i2c_write(priv, ICSIER, SAR); rcar_i2c_write(priv, ICSCR, SIE | SDBS); return 0; } static int rcar_unreg_slave(struct i2c_client *slave) { struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter); WARN_ON(!priv->slave); /* ensure no irq is running before clearing ptr */ disable_irq(priv->irq); rcar_i2c_write(priv, ICSIER, 0); rcar_i2c_write(priv, ICSSR, 0); enable_irq(priv->irq); rcar_i2c_write(priv, ICSCR, SDBS); rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ priv->slave = NULL; pm_runtime_put(rcar_i2c_priv_to_dev(priv)); return 0; } static u32 rcar_i2c_func(struct i2c_adapter *adap) { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); /* * This HW can't do: * I2C_SMBUS_QUICK (setting FSB during START didn't work) * I2C_M_NOSTART (automatically sends address after START) * I2C_M_IGNORE_NAK (automatically sends STOP after NAK) */ u32 func = I2C_FUNC_I2C | I2C_FUNC_SLAVE | (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK); if (priv->flags & ID_P_HOST_NOTIFY) func |= I2C_FUNC_SMBUS_HOST_NOTIFY; return func; } static const struct i2c_algorithm rcar_i2c_algo = { .master_xfer = rcar_i2c_master_xfer, .master_xfer_atomic = rcar_i2c_master_xfer_atomic, .functionality = rcar_i2c_func, .reg_slave = rcar_reg_slave, .unreg_slave = rcar_unreg_slave, }; static const struct i2c_adapter_quirks rcar_i2c_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, }; static const struct of_device_id rcar_i2c_dt_ids[] = { { .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 }, { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 }, { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 }, { .compatible = "renesas,i2c-r8a7796", .data = (void *)I2C_RCAR_GEN3 }, { .compatible = "renesas,rcar-gen1-i2c", .data = (void *)I2C_RCAR_GEN1 }, { .compatible = "renesas,rcar-gen2-i2c", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,rcar-gen3-i2c", .data = (void *)I2C_RCAR_GEN3 }, { .compatible = "renesas,rcar-gen4-i2c", .data = (void *)I2C_RCAR_GEN3 }, {}, }; MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids); static int rcar_i2c_probe(struct platform_device *pdev) { struct rcar_i2c_priv *priv; struct i2c_adapter *adap; struct device *dev = &pdev->dev; unsigned long irqflags = 0; irqreturn_t (*irqhandler)(int irq, void *ptr) = rcar_i2c_gen3_irq; int ret; /* Otherwise logic will break because some bytes must always use PIO */ BUILD_BUG_ON_MSG(RCAR_MIN_DMA_LEN < 3, "Invalid min DMA length"); priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->clk = devm_clk_get(dev, NULL); if (IS_ERR(priv->clk)) { dev_err(dev, "cannot get clock\n"); return PTR_ERR(priv->clk); } priv->io = devm_platform_get_and_ioremap_resource(pdev, 0, &priv->res); if (IS_ERR(priv->io)) return PTR_ERR(priv->io); priv->devtype = (enum rcar_i2c_type)of_device_get_match_data(dev); init_waitqueue_head(&priv->wait); adap = &priv->adap; adap->nr = pdev->id; adap->algo = &rcar_i2c_algo; adap->class = I2C_CLASS_DEPRECATED; adap->retries = 3; adap->dev.parent = dev; adap->dev.of_node = dev->of_node; adap->bus_recovery_info = &rcar_i2c_bri; adap->quirks = &rcar_i2c_quirks; i2c_set_adapdata(adap, priv); strscpy(adap->name, pdev->name, sizeof(adap->name)); /* Init DMA */ sg_init_table(&priv->sg, 1); priv->dma_direction = DMA_NONE; priv->dma_rx = priv->dma_tx = ERR_PTR(-EPROBE_DEFER); /* Activate device for clock calculation */ pm_runtime_enable(dev); pm_runtime_get_sync(dev); ret = rcar_i2c_clock_calculate(priv); if (ret < 0) { pm_runtime_put(dev); goto out_pm_disable; } rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ if (priv->devtype < I2C_RCAR_GEN3) { irqflags |= IRQF_NO_THREAD; irqhandler = rcar_i2c_gen2_irq; } if (priv->devtype == I2C_RCAR_GEN3) { priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); if (!IS_ERR(priv->rstc)) { ret = reset_control_status(priv->rstc); if (ret < 0) priv->rstc = ERR_PTR(-ENOTSUPP); } } /* Stay always active when multi-master to keep arbitration working */ if (of_property_read_bool(dev->of_node, "multi-master")) priv->flags |= ID_P_PM_BLOCKED; else pm_runtime_put(dev); if (of_property_read_bool(dev->of_node, "smbus")) priv->flags |= ID_P_HOST_NOTIFY; ret = platform_get_irq(pdev, 0); if (ret < 0) goto out_pm_put; priv->irq = ret; ret = devm_request_irq(dev, priv->irq, irqhandler, irqflags, dev_name(dev), priv); if (ret < 0) { dev_err(dev, "cannot get irq %d\n", priv->irq); goto out_pm_put; } platform_set_drvdata(pdev, priv); ret = i2c_add_numbered_adapter(adap); if (ret < 0) goto out_pm_put; if (priv->flags & ID_P_HOST_NOTIFY) { priv->host_notify_client = i2c_new_slave_host_notify_device(adap); if (IS_ERR(priv->host_notify_client)) { ret = PTR_ERR(priv->host_notify_client); goto out_del_device; } } dev_info(dev, "probed\n"); return 0; out_del_device: i2c_del_adapter(&priv->adap); out_pm_put: if (priv->flags & ID_P_PM_BLOCKED) pm_runtime_put(dev); out_pm_disable: pm_runtime_disable(dev); return ret; } static void rcar_i2c_remove(struct platform_device *pdev) { struct rcar_i2c_priv *priv = platform_get_drvdata(pdev); struct device *dev = &pdev->dev; if (priv->host_notify_client) i2c_free_slave_host_notify_device(priv->host_notify_client); i2c_del_adapter(&priv->adap); rcar_i2c_release_dma(priv); if (priv->flags & ID_P_PM_BLOCKED) pm_runtime_put(dev); pm_runtime_disable(dev); } #ifdef CONFIG_PM_SLEEP static int rcar_i2c_suspend(struct device *dev) { struct rcar_i2c_priv *priv = dev_get_drvdata(dev); i2c_mark_adapter_suspended(&priv->adap); return 0; } static int rcar_i2c_resume(struct device *dev) { struct rcar_i2c_priv *priv = dev_get_drvdata(dev); i2c_mark_adapter_resumed(&priv->adap); return 0; } static const struct dev_pm_ops rcar_i2c_pm_ops = { SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rcar_i2c_suspend, rcar_i2c_resume) }; #define DEV_PM_OPS (&rcar_i2c_pm_ops) #else #define DEV_PM_OPS NULL #endif /* CONFIG_PM_SLEEP */ static struct platform_driver rcar_i2c_driver = { .driver = { .name = "i2c-rcar", .of_match_table = rcar_i2c_dt_ids, .pm = DEV_PM_OPS, }, .probe = rcar_i2c_probe, .remove_new = rcar_i2c_remove, }; module_platform_driver(rcar_i2c_driver); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Renesas R-Car I2C bus driver"); MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
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