| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Maxime Coquelin | 3382 | 94.44% | 3 | 20.00% |
| Peter Griffin | 173 | 4.83% | 1 | 6.67% |
| Wolfram Sang | 12 | 0.34% | 2 | 13.33% |
| Andy Shevchenko | 3 | 0.08% | 1 | 6.67% |
| Linus Torvalds | 2 | 0.06% | 1 | 6.67% |
| Masahiro Yamada | 2 | 0.06% | 1 | 6.67% |
| Thomas Gleixner | 2 | 0.06% | 1 | 6.67% |
| Dmitry V. Krivenok | 1 | 0.03% | 1 | 6.67% |
| Jingoo Han | 1 | 0.03% | 1 | 6.67% |
| Bhumika Goyal | 1 | 0.03% | 1 | 6.67% |
| Fabio Estevam | 1 | 0.03% | 1 | 6.67% |
| Alain Volmat | 1 | 0.03% | 1 | 6.67% |
| Total | 3581 | 15 |
// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2013 STMicroelectronics * * I2C master mode controller driver, used in STMicroelectronics devices. * * Author: Maxime Coquelin <maxime.coquelin@st.com> */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> /* SSC registers */ #define SSC_BRG 0x000 #define SSC_TBUF 0x004 #define SSC_RBUF 0x008 #define SSC_CTL 0x00C #define SSC_IEN 0x010 #define SSC_STA 0x014 #define SSC_I2C 0x018 #define SSC_SLAD 0x01C #define SSC_REP_START_HOLD 0x020 #define SSC_START_HOLD 0x024 #define SSC_REP_START_SETUP 0x028 #define SSC_DATA_SETUP 0x02C #define SSC_STOP_SETUP 0x030 #define SSC_BUS_FREE 0x034 #define SSC_TX_FSTAT 0x038 #define SSC_RX_FSTAT 0x03C #define SSC_PRE_SCALER_BRG 0x040 #define SSC_CLR 0x080 #define SSC_NOISE_SUPP_WIDTH 0x100 #define SSC_PRSCALER 0x104 #define SSC_NOISE_SUPP_WIDTH_DATAOUT 0x108 #define SSC_PRSCALER_DATAOUT 0x10c /* SSC Control */ #define SSC_CTL_DATA_WIDTH_9 0x8 #define SSC_CTL_DATA_WIDTH_MSK 0xf #define SSC_CTL_BM 0xf #define SSC_CTL_HB BIT(4) #define SSC_CTL_PH BIT(5) #define SSC_CTL_PO BIT(6) #define SSC_CTL_SR BIT(7) #define SSC_CTL_MS BIT(8) #define SSC_CTL_EN BIT(9) #define SSC_CTL_LPB BIT(10) #define SSC_CTL_EN_TX_FIFO BIT(11) #define SSC_CTL_EN_RX_FIFO BIT(12) #define SSC_CTL_EN_CLST_RX BIT(13) /* SSC Interrupt Enable */ #define SSC_IEN_RIEN BIT(0) #define SSC_IEN_TIEN BIT(1) #define SSC_IEN_TEEN BIT(2) #define SSC_IEN_REEN BIT(3) #define SSC_IEN_PEEN BIT(4) #define SSC_IEN_AASEN BIT(6) #define SSC_IEN_STOPEN BIT(7) #define SSC_IEN_ARBLEN BIT(8) #define SSC_IEN_NACKEN BIT(10) #define SSC_IEN_REPSTRTEN BIT(11) #define SSC_IEN_TX_FIFO_HALF BIT(12) #define SSC_IEN_RX_FIFO_HALF_FULL BIT(14) /* SSC Status */ #define SSC_STA_RIR BIT(0) #define SSC_STA_TIR BIT(1) #define SSC_STA_TE BIT(2) #define SSC_STA_RE BIT(3) #define SSC_STA_PE BIT(4) #define SSC_STA_CLST BIT(5) #define SSC_STA_AAS BIT(6) #define SSC_STA_STOP BIT(7) #define SSC_STA_ARBL BIT(8) #define SSC_STA_BUSY BIT(9) #define SSC_STA_NACK BIT(10) #define SSC_STA_REPSTRT BIT(11) #define SSC_STA_TX_FIFO_HALF BIT(12) #define SSC_STA_TX_FIFO_FULL BIT(13) #define SSC_STA_RX_FIFO_HALF BIT(14) /* SSC I2C Control */ #define SSC_I2C_I2CM BIT(0) #define SSC_I2C_STRTG BIT(1) #define SSC_I2C_STOPG BIT(2) #define SSC_I2C_ACKG BIT(3) #define SSC_I2C_AD10 BIT(4) #define SSC_I2C_TXENB BIT(5) #define SSC_I2C_REPSTRTG BIT(11) #define SSC_I2C_SLAVE_DISABLE BIT(12) /* SSC Tx FIFO Status */ #define SSC_TX_FSTAT_STATUS 0x07 /* SSC Rx FIFO Status */ #define SSC_RX_FSTAT_STATUS 0x07 /* SSC Clear bit operation */ #define SSC_CLR_SSCAAS BIT(6) #define SSC_CLR_SSCSTOP BIT(7) #define SSC_CLR_SSCARBL BIT(8) #define SSC_CLR_NACK BIT(10) #define SSC_CLR_REPSTRT BIT(11) /* SSC Clock Prescaler */ #define SSC_PRSC_VALUE 0x0f #define SSC_TXFIFO_SIZE 0x8 #define SSC_RXFIFO_SIZE 0x8 enum st_i2c_mode { I2C_MODE_STANDARD, I2C_MODE_FAST, I2C_MODE_END, }; /** * struct st_i2c_timings - per-Mode tuning parameters * @rate: I2C bus rate * @rep_start_hold: I2C repeated start hold time requirement * @rep_start_setup: I2C repeated start set up time requirement * @start_hold: I2C start hold time requirement * @data_setup_time: I2C data set up time requirement * @stop_setup_time: I2C stop set up time requirement * @bus_free_time: I2C bus free time requirement * @sda_pulse_min_limit: I2C SDA pulse mini width limit */ struct st_i2c_timings { u32 rate; u32 rep_start_hold; u32 rep_start_setup; u32 start_hold; u32 data_setup_time; u32 stop_setup_time; u32 bus_free_time; u32 sda_pulse_min_limit; }; /** * struct st_i2c_client - client specific data * @addr: 8-bit slave addr, including r/w bit * @count: number of bytes to be transfered * @xfered: number of bytes already transferred * @buf: data buffer * @result: result of the transfer * @stop: last I2C msg to be sent, i.e. STOP to be generated */ struct st_i2c_client { u8 addr; u32 count; u32 xfered; u8 *buf; int result; bool stop; }; /** * struct st_i2c_dev - private data of the controller * @adap: I2C adapter for this controller * @dev: device for this controller * @base: virtual memory area * @complete: completion of I2C message * @irq: interrupt line for th controller * @clk: hw ssc block clock * @mode: I2C mode of the controller. Standard or Fast only supported * @scl_min_width_us: SCL line minimum pulse width in us * @sda_min_width_us: SDA line minimum pulse width in us * @client: I2C transfert information * @busy: I2C transfer on-going */ struct st_i2c_dev { struct i2c_adapter adap; struct device *dev; void __iomem *base; struct completion complete; int irq; struct clk *clk; int mode; u32 scl_min_width_us; u32 sda_min_width_us; struct st_i2c_client client; bool busy; }; static inline void st_i2c_set_bits(void __iomem *reg, u32 mask) { writel_relaxed(readl_relaxed(reg) | mask, reg); } static inline void st_i2c_clr_bits(void __iomem *reg, u32 mask) { writel_relaxed(readl_relaxed(reg) & ~mask, reg); } /* * From I2C Specifications v0.5. * * All the values below have +10% margin added to be * compatible with some out-of-spec devices, * like HDMI link of the Toshiba 19AV600 TV. */ static struct st_i2c_timings i2c_timings[] = { [I2C_MODE_STANDARD] = { .rate = I2C_MAX_STANDARD_MODE_FREQ, .rep_start_hold = 4400, .rep_start_setup = 5170, .start_hold = 4400, .data_setup_time = 275, .stop_setup_time = 4400, .bus_free_time = 5170, }, [I2C_MODE_FAST] = { .rate = I2C_MAX_FAST_MODE_FREQ, .rep_start_hold = 660, .rep_start_setup = 660, .start_hold = 660, .data_setup_time = 110, .stop_setup_time = 660, .bus_free_time = 1430, }, }; static void st_i2c_flush_rx_fifo(struct st_i2c_dev *i2c_dev) { int count, i; /* * Counter only counts up to 7 but fifo size is 8... * When fifo is full, counter is 0 and RIR bit of status register is * set */ if (readl_relaxed(i2c_dev->base + SSC_STA) & SSC_STA_RIR) count = SSC_RXFIFO_SIZE; else count = readl_relaxed(i2c_dev->base + SSC_RX_FSTAT) & SSC_RX_FSTAT_STATUS; for (i = 0; i < count; i++) readl_relaxed(i2c_dev->base + SSC_RBUF); } static void st_i2c_soft_reset(struct st_i2c_dev *i2c_dev) { /* * FIFO needs to be emptied before reseting the IP, * else the controller raises a BUSY error. */ st_i2c_flush_rx_fifo(i2c_dev); st_i2c_set_bits(i2c_dev->base + SSC_CTL, SSC_CTL_SR); st_i2c_clr_bits(i2c_dev->base + SSC_CTL, SSC_CTL_SR); } /** * st_i2c_hw_config() - Prepare SSC block, calculate and apply tuning timings * @i2c_dev: Controller's private data */ static void st_i2c_hw_config(struct st_i2c_dev *i2c_dev) { unsigned long rate; u32 val, ns_per_clk; struct st_i2c_timings *t = &i2c_timings[i2c_dev->mode]; st_i2c_soft_reset(i2c_dev); val = SSC_CLR_REPSTRT | SSC_CLR_NACK | SSC_CLR_SSCARBL | SSC_CLR_SSCAAS | SSC_CLR_SSCSTOP; writel_relaxed(val, i2c_dev->base + SSC_CLR); /* SSC Control register setup */ val = SSC_CTL_PO | SSC_CTL_PH | SSC_CTL_HB | SSC_CTL_DATA_WIDTH_9; writel_relaxed(val, i2c_dev->base + SSC_CTL); rate = clk_get_rate(i2c_dev->clk); ns_per_clk = 1000000000 / rate; /* Baudrate */ val = rate / (2 * t->rate); writel_relaxed(val, i2c_dev->base + SSC_BRG); /* Pre-scaler baudrate */ writel_relaxed(1, i2c_dev->base + SSC_PRE_SCALER_BRG); /* Enable I2C mode */ writel_relaxed(SSC_I2C_I2CM, i2c_dev->base + SSC_I2C); /* Repeated start hold time */ val = t->rep_start_hold / ns_per_clk; writel_relaxed(val, i2c_dev->base + SSC_REP_START_HOLD); /* Repeated start set up time */ val = t->rep_start_setup / ns_per_clk; writel_relaxed(val, i2c_dev->base + SSC_REP_START_SETUP); /* Start hold time */ val = t->start_hold / ns_per_clk; writel_relaxed(val, i2c_dev->base + SSC_START_HOLD); /* Data set up time */ val = t->data_setup_time / ns_per_clk; writel_relaxed(val, i2c_dev->base + SSC_DATA_SETUP); /* Stop set up time */ val = t->stop_setup_time / ns_per_clk; writel_relaxed(val, i2c_dev->base + SSC_STOP_SETUP); /* Bus free time */ val = t->bus_free_time / ns_per_clk; writel_relaxed(val, i2c_dev->base + SSC_BUS_FREE); /* Prescalers set up */ val = rate / 10000000; writel_relaxed(val, i2c_dev->base + SSC_PRSCALER); writel_relaxed(val, i2c_dev->base + SSC_PRSCALER_DATAOUT); /* Noise suppression witdh */ val = i2c_dev->scl_min_width_us * rate / 100000000; writel_relaxed(val, i2c_dev->base + SSC_NOISE_SUPP_WIDTH); /* Noise suppression max output data delay width */ val = i2c_dev->sda_min_width_us * rate / 100000000; writel_relaxed(val, i2c_dev->base + SSC_NOISE_SUPP_WIDTH_DATAOUT); } static int st_i2c_recover_bus(struct i2c_adapter *i2c_adap) { struct st_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); u32 ctl; dev_dbg(i2c_dev->dev, "Trying to recover bus\n"); /* * SSP IP is dual role SPI/I2C to generate 9 clock pulses * we switch to SPI node, 9 bit words and write a 0. This * has been validate with a oscilloscope and is easier * than switching to GPIO mode. */ /* Disable interrupts */ writel_relaxed(0, i2c_dev->base + SSC_IEN); st_i2c_hw_config(i2c_dev); ctl = SSC_CTL_EN | SSC_CTL_MS | SSC_CTL_EN_RX_FIFO | SSC_CTL_EN_TX_FIFO; st_i2c_set_bits(i2c_dev->base + SSC_CTL, ctl); st_i2c_clr_bits(i2c_dev->base + SSC_I2C, SSC_I2C_I2CM); usleep_range(8000, 10000); writel_relaxed(0, i2c_dev->base + SSC_TBUF); usleep_range(2000, 4000); st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_I2CM); return 0; } static int st_i2c_wait_free_bus(struct st_i2c_dev *i2c_dev) { u32 sta; int i, ret; for (i = 0; i < 10; i++) { sta = readl_relaxed(i2c_dev->base + SSC_STA); if (!(sta & SSC_STA_BUSY)) return 0; usleep_range(2000, 4000); } dev_err(i2c_dev->dev, "bus not free (status = 0x%08x)\n", sta); ret = i2c_recover_bus(&i2c_dev->adap); if (ret) { dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret); return ret; } return -EBUSY; } /** * st_i2c_write_tx_fifo() - Write a byte in the Tx FIFO * @i2c_dev: Controller's private data * @byte: Data to write in the Tx FIFO */ static inline void st_i2c_write_tx_fifo(struct st_i2c_dev *i2c_dev, u8 byte) { u16 tbuf = byte << 1; writel_relaxed(tbuf | 1, i2c_dev->base + SSC_TBUF); } /** * st_i2c_wr_fill_tx_fifo() - Fill the Tx FIFO in write mode * @i2c_dev: Controller's private data * * This functions fills the Tx FIFO with I2C transfert buffer when * in write mode. */ static void st_i2c_wr_fill_tx_fifo(struct st_i2c_dev *i2c_dev) { struct st_i2c_client *c = &i2c_dev->client; u32 tx_fstat, sta; int i; sta = readl_relaxed(i2c_dev->base + SSC_STA); if (sta & SSC_STA_TX_FIFO_FULL) return; tx_fstat = readl_relaxed(i2c_dev->base + SSC_TX_FSTAT); tx_fstat &= SSC_TX_FSTAT_STATUS; if (c->count < (SSC_TXFIFO_SIZE - tx_fstat)) i = c->count; else i = SSC_TXFIFO_SIZE - tx_fstat; for (; i > 0; i--, c->count--, c->buf++) st_i2c_write_tx_fifo(i2c_dev, *c->buf); } /** * st_i2c_rd_fill_tx_fifo() - Fill the Tx FIFO in read mode * @i2c_dev: Controller's private data * @max: Maximum amount of data to fill into the Tx FIFO * * This functions fills the Tx FIFO with fixed pattern when * in read mode to trigger clock. */ static void st_i2c_rd_fill_tx_fifo(struct st_i2c_dev *i2c_dev, int max) { struct st_i2c_client *c = &i2c_dev->client; u32 tx_fstat, sta; int i; sta = readl_relaxed(i2c_dev->base + SSC_STA); if (sta & SSC_STA_TX_FIFO_FULL) return; tx_fstat = readl_relaxed(i2c_dev->base + SSC_TX_FSTAT); tx_fstat &= SSC_TX_FSTAT_STATUS; if (max < (SSC_TXFIFO_SIZE - tx_fstat)) i = max; else i = SSC_TXFIFO_SIZE - tx_fstat; for (; i > 0; i--, c->xfered++) st_i2c_write_tx_fifo(i2c_dev, 0xff); } static void st_i2c_read_rx_fifo(struct st_i2c_dev *i2c_dev) { struct st_i2c_client *c = &i2c_dev->client; u32 i, sta; u16 rbuf; sta = readl_relaxed(i2c_dev->base + SSC_STA); if (sta & SSC_STA_RIR) { i = SSC_RXFIFO_SIZE; } else { i = readl_relaxed(i2c_dev->base + SSC_RX_FSTAT); i &= SSC_RX_FSTAT_STATUS; } for (; (i > 0) && (c->count > 0); i--, c->count--) { rbuf = readl_relaxed(i2c_dev->base + SSC_RBUF) >> 1; *c->buf++ = (u8)rbuf & 0xff; } if (i) { dev_err(i2c_dev->dev, "Unexpected %d bytes in rx fifo\n", i); st_i2c_flush_rx_fifo(i2c_dev); } } /** * st_i2c_terminate_xfer() - Send either STOP or REPSTART condition * @i2c_dev: Controller's private data */ static void st_i2c_terminate_xfer(struct st_i2c_dev *i2c_dev) { struct st_i2c_client *c = &i2c_dev->client; st_i2c_clr_bits(i2c_dev->base + SSC_IEN, SSC_IEN_TEEN); st_i2c_clr_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STRTG); if (c->stop) { st_i2c_set_bits(i2c_dev->base + SSC_IEN, SSC_IEN_STOPEN); st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STOPG); } else { st_i2c_set_bits(i2c_dev->base + SSC_IEN, SSC_IEN_REPSTRTEN); st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_REPSTRTG); } } /** * st_i2c_handle_write() - Handle FIFO empty interrupt in case of write * @i2c_dev: Controller's private data */ static void st_i2c_handle_write(struct st_i2c_dev *i2c_dev) { struct st_i2c_client *c = &i2c_dev->client; st_i2c_flush_rx_fifo(i2c_dev); if (!c->count) /* End of xfer, send stop or repstart */ st_i2c_terminate_xfer(i2c_dev); else st_i2c_wr_fill_tx_fifo(i2c_dev); } /** * st_i2c_handle_write() - Handle FIFO enmpty interrupt in case of read * @i2c_dev: Controller's private data */ static void st_i2c_handle_read(struct st_i2c_dev *i2c_dev) { struct st_i2c_client *c = &i2c_dev->client; u32 ien; /* Trash the address read back */ if (!c->xfered) { readl_relaxed(i2c_dev->base + SSC_RBUF); st_i2c_clr_bits(i2c_dev->base + SSC_I2C, SSC_I2C_TXENB); } else { st_i2c_read_rx_fifo(i2c_dev); } if (!c->count) { /* End of xfer, send stop or repstart */ st_i2c_terminate_xfer(i2c_dev); } else if (c->count == 1) { /* Penultimate byte to xfer, disable ACK gen. */ st_i2c_clr_bits(i2c_dev->base + SSC_I2C, SSC_I2C_ACKG); /* Last received byte is to be handled by NACK interrupt */ ien = SSC_IEN_NACKEN | SSC_IEN_ARBLEN; writel_relaxed(ien, i2c_dev->base + SSC_IEN); st_i2c_rd_fill_tx_fifo(i2c_dev, c->count); } else { st_i2c_rd_fill_tx_fifo(i2c_dev, c->count - 1); } } /** * st_i2c_isr() - Interrupt routine * @irq: interrupt number * @data: Controller's private data */ static irqreturn_t st_i2c_isr_thread(int irq, void *data) { struct st_i2c_dev *i2c_dev = data; struct st_i2c_client *c = &i2c_dev->client; u32 sta, ien; int it; ien = readl_relaxed(i2c_dev->base + SSC_IEN); sta = readl_relaxed(i2c_dev->base + SSC_STA); /* Use __fls() to check error bits first */ it = __fls(sta & ien); if (it < 0) { dev_dbg(i2c_dev->dev, "spurious it (sta=0x%04x, ien=0x%04x)\n", sta, ien); return IRQ_NONE; } switch (1 << it) { case SSC_STA_TE: if (c->addr & I2C_M_RD) st_i2c_handle_read(i2c_dev); else st_i2c_handle_write(i2c_dev); break; case SSC_STA_STOP: case SSC_STA_REPSTRT: writel_relaxed(0, i2c_dev->base + SSC_IEN); complete(&i2c_dev->complete); break; case SSC_STA_NACK: writel_relaxed(SSC_CLR_NACK, i2c_dev->base + SSC_CLR); /* Last received byte handled by NACK interrupt */ if ((c->addr & I2C_M_RD) && (c->count == 1) && (c->xfered)) { st_i2c_handle_read(i2c_dev); break; } it = SSC_IEN_STOPEN | SSC_IEN_ARBLEN; writel_relaxed(it, i2c_dev->base + SSC_IEN); st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STOPG); c->result = -EIO; break; case SSC_STA_ARBL: writel_relaxed(SSC_CLR_SSCARBL, i2c_dev->base + SSC_CLR); it = SSC_IEN_STOPEN | SSC_IEN_ARBLEN; writel_relaxed(it, i2c_dev->base + SSC_IEN); st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STOPG); c->result = -EAGAIN; break; default: dev_err(i2c_dev->dev, "it %d unhandled (sta=0x%04x)\n", it, sta); } /* * Read IEN register to ensure interrupt mask write is effective * before re-enabling interrupt at GIC level, and thus avoid spurious * interrupts. */ readl(i2c_dev->base + SSC_IEN); return IRQ_HANDLED; } /** * st_i2c_xfer_msg() - Transfer a single I2C message * @i2c_dev: Controller's private data * @msg: I2C message to transfer * @is_first: first message of the sequence * @is_last: last message of the sequence */ static int st_i2c_xfer_msg(struct st_i2c_dev *i2c_dev, struct i2c_msg *msg, bool is_first, bool is_last) { struct st_i2c_client *c = &i2c_dev->client; u32 ctl, i2c, it; unsigned long timeout; int ret; c->addr = i2c_8bit_addr_from_msg(msg); c->buf = msg->buf; c->count = msg->len; c->xfered = 0; c->result = 0; c->stop = is_last; reinit_completion(&i2c_dev->complete); ctl = SSC_CTL_EN | SSC_CTL_MS | SSC_CTL_EN_RX_FIFO | SSC_CTL_EN_TX_FIFO; st_i2c_set_bits(i2c_dev->base + SSC_CTL, ctl); i2c = SSC_I2C_TXENB; if (c->addr & I2C_M_RD) i2c |= SSC_I2C_ACKG; st_i2c_set_bits(i2c_dev->base + SSC_I2C, i2c); /* Write slave address */ st_i2c_write_tx_fifo(i2c_dev, c->addr); /* Pre-fill Tx fifo with data in case of write */ if (!(c->addr & I2C_M_RD)) st_i2c_wr_fill_tx_fifo(i2c_dev); it = SSC_IEN_NACKEN | SSC_IEN_TEEN | SSC_IEN_ARBLEN; writel_relaxed(it, i2c_dev->base + SSC_IEN); if (is_first) { ret = st_i2c_wait_free_bus(i2c_dev); if (ret) return ret; st_i2c_set_bits(i2c_dev->base + SSC_I2C, SSC_I2C_STRTG); } timeout = wait_for_completion_timeout(&i2c_dev->complete, i2c_dev->adap.timeout); ret = c->result; if (!timeout) { dev_err(i2c_dev->dev, "Write to slave 0x%x timed out\n", c->addr); ret = -ETIMEDOUT; } i2c = SSC_I2C_STOPG | SSC_I2C_REPSTRTG; st_i2c_clr_bits(i2c_dev->base + SSC_I2C, i2c); writel_relaxed(SSC_CLR_SSCSTOP | SSC_CLR_REPSTRT, i2c_dev->base + SSC_CLR); return ret; } /** * st_i2c_xfer() - Transfer a single I2C message * @i2c_adap: Adapter pointer to the controller * @msgs: Pointer to data to be written. * @num: Number of messages to be executed */ static int st_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], int num) { struct st_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); int ret, i; i2c_dev->busy = true; ret = clk_prepare_enable(i2c_dev->clk); if (ret) { dev_err(i2c_dev->dev, "Failed to prepare_enable clock\n"); return ret; } pinctrl_pm_select_default_state(i2c_dev->dev); st_i2c_hw_config(i2c_dev); for (i = 0; (i < num) && !ret; i++) ret = st_i2c_xfer_msg(i2c_dev, &msgs[i], i == 0, i == num - 1); pinctrl_pm_select_idle_state(i2c_dev->dev); clk_disable_unprepare(i2c_dev->clk); i2c_dev->busy = false; return (ret < 0) ? ret : i; } #ifdef CONFIG_PM_SLEEP static int st_i2c_suspend(struct device *dev) { struct st_i2c_dev *i2c_dev = dev_get_drvdata(dev); if (i2c_dev->busy) return -EBUSY; pinctrl_pm_select_sleep_state(dev); return 0; } static int st_i2c_resume(struct device *dev) { pinctrl_pm_select_default_state(dev); /* Go in idle state if available */ pinctrl_pm_select_idle_state(dev); return 0; } static SIMPLE_DEV_PM_OPS(st_i2c_pm, st_i2c_suspend, st_i2c_resume); #define ST_I2C_PM (&st_i2c_pm) #else #define ST_I2C_PM NULL #endif static u32 st_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static const struct i2c_algorithm st_i2c_algo = { .master_xfer = st_i2c_xfer, .functionality = st_i2c_func, }; static struct i2c_bus_recovery_info st_i2c_recovery_info = { .recover_bus = st_i2c_recover_bus, }; static int st_i2c_of_get_deglitch(struct device_node *np, struct st_i2c_dev *i2c_dev) { int ret; ret = of_property_read_u32(np, "st,i2c-min-scl-pulse-width-us", &i2c_dev->scl_min_width_us); if ((ret == -ENODATA) || (ret == -EOVERFLOW)) { dev_err(i2c_dev->dev, "st,i2c-min-scl-pulse-width-us invalid\n"); return ret; } ret = of_property_read_u32(np, "st,i2c-min-sda-pulse-width-us", &i2c_dev->sda_min_width_us); if ((ret == -ENODATA) || (ret == -EOVERFLOW)) { dev_err(i2c_dev->dev, "st,i2c-min-sda-pulse-width-us invalid\n"); return ret; } return 0; } static int st_i2c_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct st_i2c_dev *i2c_dev; struct resource *res; u32 clk_rate; struct i2c_adapter *adap; int ret; i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); if (!i2c_dev) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c_dev->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(i2c_dev->base)) return PTR_ERR(i2c_dev->base); i2c_dev->irq = irq_of_parse_and_map(np, 0); if (!i2c_dev->irq) { dev_err(&pdev->dev, "IRQ missing or invalid\n"); return -EINVAL; } i2c_dev->clk = of_clk_get_by_name(np, "ssc"); if (IS_ERR(i2c_dev->clk)) { dev_err(&pdev->dev, "Unable to request clock\n"); return PTR_ERR(i2c_dev->clk); } i2c_dev->mode = I2C_MODE_STANDARD; ret = of_property_read_u32(np, "clock-frequency", &clk_rate); if (!ret && (clk_rate == I2C_MAX_FAST_MODE_FREQ)) i2c_dev->mode = I2C_MODE_FAST; i2c_dev->dev = &pdev->dev; ret = devm_request_threaded_irq(&pdev->dev, i2c_dev->irq, NULL, st_i2c_isr_thread, IRQF_ONESHOT, pdev->name, i2c_dev); if (ret) { dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq); return ret; } pinctrl_pm_select_default_state(i2c_dev->dev); /* In case idle state available, select it */ pinctrl_pm_select_idle_state(i2c_dev->dev); ret = st_i2c_of_get_deglitch(np, i2c_dev); if (ret) return ret; adap = &i2c_dev->adap; i2c_set_adapdata(adap, i2c_dev); snprintf(adap->name, sizeof(adap->name), "ST I2C(%pa)", &res->start); adap->owner = THIS_MODULE; adap->timeout = 2 * HZ; adap->retries = 0; adap->algo = &st_i2c_algo; adap->bus_recovery_info = &st_i2c_recovery_info; adap->dev.parent = &pdev->dev; adap->dev.of_node = pdev->dev.of_node; init_completion(&i2c_dev->complete); ret = i2c_add_adapter(adap); if (ret) return ret; platform_set_drvdata(pdev, i2c_dev); dev_info(i2c_dev->dev, "%s initialized\n", adap->name); return 0; } static int st_i2c_remove(struct platform_device *pdev) { struct st_i2c_dev *i2c_dev = platform_get_drvdata(pdev); i2c_del_adapter(&i2c_dev->adap); return 0; } static const struct of_device_id st_i2c_match[] = { { .compatible = "st,comms-ssc-i2c", }, { .compatible = "st,comms-ssc4-i2c", }, {}, }; MODULE_DEVICE_TABLE(of, st_i2c_match); static struct platform_driver st_i2c_driver = { .driver = { .name = "st-i2c", .of_match_table = st_i2c_match, .pm = ST_I2C_PM, }, .probe = st_i2c_probe, .remove = st_i2c_remove, }; module_platform_driver(st_i2c_driver); MODULE_AUTHOR("Maxime Coquelin <maxime.coquelin@st.com>"); MODULE_DESCRIPTION("STMicroelectronics I2C driver"); MODULE_LICENSE("GPL v2");
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