diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-stm32f7.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-stm32f7.c | 2497 |
1 files changed, 2497 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c new file mode 100644 index 000000000..0d3c9a041 --- /dev/null +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -0,0 +1,2497 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for STMicroelectronics STM32F7 I2C controller + * + * This I2C controller is described in the STM32F75xxx and STM32F74xxx Soc + * reference manual. + * Please see below a link to the documentation: + * http://www.st.com/resource/en/reference_manual/dm00124865.pdf + * + * Copyright (C) M'boumba Cedric Madianga 2017 + * Copyright (C) STMicroelectronics 2017 + * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com> + * + * This driver is based on i2c-stm32f4.c + * + */ +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/i2c-smbus.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pinctrl/consumer.h> +#include <linux/pm_runtime.h> +#include <linux/pm_wakeirq.h> +#include <linux/regmap.h> +#include <linux/reset.h> +#include <linux/slab.h> + +#include "i2c-stm32.h" + +/* STM32F7 I2C registers */ +#define STM32F7_I2C_CR1 0x00 +#define STM32F7_I2C_CR2 0x04 +#define STM32F7_I2C_OAR1 0x08 +#define STM32F7_I2C_OAR2 0x0C +#define STM32F7_I2C_PECR 0x20 +#define STM32F7_I2C_TIMINGR 0x10 +#define STM32F7_I2C_ISR 0x18 +#define STM32F7_I2C_ICR 0x1C +#define STM32F7_I2C_RXDR 0x24 +#define STM32F7_I2C_TXDR 0x28 + +/* STM32F7 I2C control 1 */ +#define STM32F7_I2C_CR1_PECEN BIT(23) +#define STM32F7_I2C_CR1_ALERTEN BIT(22) +#define STM32F7_I2C_CR1_SMBHEN BIT(20) +#define STM32F7_I2C_CR1_WUPEN BIT(18) +#define STM32F7_I2C_CR1_SBC BIT(16) +#define STM32F7_I2C_CR1_RXDMAEN BIT(15) +#define STM32F7_I2C_CR1_TXDMAEN BIT(14) +#define STM32F7_I2C_CR1_ANFOFF BIT(12) +#define STM32F7_I2C_CR1_DNF_MASK GENMASK(11, 8) +#define STM32F7_I2C_CR1_DNF(n) (((n) & 0xf) << 8) +#define STM32F7_I2C_CR1_ERRIE BIT(7) +#define STM32F7_I2C_CR1_TCIE BIT(6) +#define STM32F7_I2C_CR1_STOPIE BIT(5) +#define STM32F7_I2C_CR1_NACKIE BIT(4) +#define STM32F7_I2C_CR1_ADDRIE BIT(3) +#define STM32F7_I2C_CR1_RXIE BIT(2) +#define STM32F7_I2C_CR1_TXIE BIT(1) +#define STM32F7_I2C_CR1_PE BIT(0) +#define STM32F7_I2C_ALL_IRQ_MASK (STM32F7_I2C_CR1_ERRIE \ + | STM32F7_I2C_CR1_TCIE \ + | STM32F7_I2C_CR1_STOPIE \ + | STM32F7_I2C_CR1_NACKIE \ + | STM32F7_I2C_CR1_RXIE \ + | STM32F7_I2C_CR1_TXIE) +#define STM32F7_I2C_XFER_IRQ_MASK (STM32F7_I2C_CR1_TCIE \ + | STM32F7_I2C_CR1_STOPIE \ + | STM32F7_I2C_CR1_NACKIE \ + | STM32F7_I2C_CR1_RXIE \ + | STM32F7_I2C_CR1_TXIE) + +/* STM32F7 I2C control 2 */ +#define STM32F7_I2C_CR2_PECBYTE BIT(26) +#define STM32F7_I2C_CR2_RELOAD BIT(24) +#define STM32F7_I2C_CR2_NBYTES_MASK GENMASK(23, 16) +#define STM32F7_I2C_CR2_NBYTES(n) (((n) & 0xff) << 16) +#define STM32F7_I2C_CR2_NACK BIT(15) +#define STM32F7_I2C_CR2_STOP BIT(14) +#define STM32F7_I2C_CR2_START BIT(13) +#define STM32F7_I2C_CR2_HEAD10R BIT(12) +#define STM32F7_I2C_CR2_ADD10 BIT(11) +#define STM32F7_I2C_CR2_RD_WRN BIT(10) +#define STM32F7_I2C_CR2_SADD10_MASK GENMASK(9, 0) +#define STM32F7_I2C_CR2_SADD10(n) (((n) & \ + STM32F7_I2C_CR2_SADD10_MASK)) +#define STM32F7_I2C_CR2_SADD7_MASK GENMASK(7, 1) +#define STM32F7_I2C_CR2_SADD7(n) (((n) & 0x7f) << 1) + +/* STM32F7 I2C Own Address 1 */ +#define STM32F7_I2C_OAR1_OA1EN BIT(15) +#define STM32F7_I2C_OAR1_OA1MODE BIT(10) +#define STM32F7_I2C_OAR1_OA1_10_MASK GENMASK(9, 0) +#define STM32F7_I2C_OAR1_OA1_10(n) (((n) & \ + STM32F7_I2C_OAR1_OA1_10_MASK)) +#define STM32F7_I2C_OAR1_OA1_7_MASK GENMASK(7, 1) +#define STM32F7_I2C_OAR1_OA1_7(n) (((n) & 0x7f) << 1) +#define STM32F7_I2C_OAR1_MASK (STM32F7_I2C_OAR1_OA1_7_MASK \ + | STM32F7_I2C_OAR1_OA1_10_MASK \ + | STM32F7_I2C_OAR1_OA1EN \ + | STM32F7_I2C_OAR1_OA1MODE) + +/* STM32F7 I2C Own Address 2 */ +#define STM32F7_I2C_OAR2_OA2EN BIT(15) +#define STM32F7_I2C_OAR2_OA2MSK_MASK GENMASK(10, 8) +#define STM32F7_I2C_OAR2_OA2MSK(n) (((n) & 0x7) << 8) +#define STM32F7_I2C_OAR2_OA2_7_MASK GENMASK(7, 1) +#define STM32F7_I2C_OAR2_OA2_7(n) (((n) & 0x7f) << 1) +#define STM32F7_I2C_OAR2_MASK (STM32F7_I2C_OAR2_OA2MSK_MASK \ + | STM32F7_I2C_OAR2_OA2_7_MASK \ + | STM32F7_I2C_OAR2_OA2EN) + +/* STM32F7 I2C Interrupt Status */ +#define STM32F7_I2C_ISR_ADDCODE_MASK GENMASK(23, 17) +#define STM32F7_I2C_ISR_ADDCODE_GET(n) \ + (((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17) +#define STM32F7_I2C_ISR_DIR BIT(16) +#define STM32F7_I2C_ISR_BUSY BIT(15) +#define STM32F7_I2C_ISR_ALERT BIT(13) +#define STM32F7_I2C_ISR_PECERR BIT(11) +#define STM32F7_I2C_ISR_ARLO BIT(9) +#define STM32F7_I2C_ISR_BERR BIT(8) +#define STM32F7_I2C_ISR_TCR BIT(7) +#define STM32F7_I2C_ISR_TC BIT(6) +#define STM32F7_I2C_ISR_STOPF BIT(5) +#define STM32F7_I2C_ISR_NACKF BIT(4) +#define STM32F7_I2C_ISR_ADDR BIT(3) +#define STM32F7_I2C_ISR_RXNE BIT(2) +#define STM32F7_I2C_ISR_TXIS BIT(1) +#define STM32F7_I2C_ISR_TXE BIT(0) + +/* STM32F7 I2C Interrupt Clear */ +#define STM32F7_I2C_ICR_ALERTCF BIT(13) +#define STM32F7_I2C_ICR_PECCF BIT(11) +#define STM32F7_I2C_ICR_ARLOCF BIT(9) +#define STM32F7_I2C_ICR_BERRCF BIT(8) +#define STM32F7_I2C_ICR_STOPCF BIT(5) +#define STM32F7_I2C_ICR_NACKCF BIT(4) +#define STM32F7_I2C_ICR_ADDRCF BIT(3) + +/* STM32F7 I2C Timing */ +#define STM32F7_I2C_TIMINGR_PRESC(n) (((n) & 0xf) << 28) +#define STM32F7_I2C_TIMINGR_SCLDEL(n) (((n) & 0xf) << 20) +#define STM32F7_I2C_TIMINGR_SDADEL(n) (((n) & 0xf) << 16) +#define STM32F7_I2C_TIMINGR_SCLH(n) (((n) & 0xff) << 8) +#define STM32F7_I2C_TIMINGR_SCLL(n) ((n) & 0xff) + +#define STM32F7_I2C_MAX_LEN 0xff +#define STM32F7_I2C_DMA_LEN_MIN 0x16 +enum { + STM32F7_SLAVE_HOSTNOTIFY, + STM32F7_SLAVE_7_10_BITS_ADDR, + STM32F7_SLAVE_7_BITS_ADDR, + STM32F7_I2C_MAX_SLAVE +}; + +#define STM32F7_I2C_DNF_DEFAULT 0 +#define STM32F7_I2C_DNF_MAX 15 + +#define STM32F7_I2C_ANALOG_FILTER_DELAY_MIN 50 /* ns */ +#define STM32F7_I2C_ANALOG_FILTER_DELAY_MAX 260 /* ns */ + +#define STM32F7_I2C_RISE_TIME_DEFAULT 25 /* ns */ +#define STM32F7_I2C_FALL_TIME_DEFAULT 10 /* ns */ + +#define STM32F7_PRESC_MAX BIT(4) +#define STM32F7_SCLDEL_MAX BIT(4) +#define STM32F7_SDADEL_MAX BIT(4) +#define STM32F7_SCLH_MAX BIT(8) +#define STM32F7_SCLL_MAX BIT(8) + +#define STM32F7_AUTOSUSPEND_DELAY (HZ / 100) + +/** + * struct stm32f7_i2c_regs - i2c f7 registers backup + * @cr1: Control register 1 + * @cr2: Control register 2 + * @oar1: Own address 1 register + * @oar2: Own address 2 register + * @tmgr: Timing register + */ +struct stm32f7_i2c_regs { + u32 cr1; + u32 cr2; + u32 oar1; + u32 oar2; + u32 tmgr; +}; + +/** + * struct stm32f7_i2c_spec - private i2c specification timing + * @rate: I2C bus speed (Hz) + * @fall_max: Max fall time of both SDA and SCL signals (ns) + * @rise_max: Max rise time of both SDA and SCL signals (ns) + * @hddat_min: Min data hold time (ns) + * @vddat_max: Max data valid time (ns) + * @sudat_min: Min data setup time (ns) + * @l_min: Min low period of the SCL clock (ns) + * @h_min: Min high period of the SCL clock (ns) + */ +struct stm32f7_i2c_spec { + u32 rate; + u32 fall_max; + u32 rise_max; + u32 hddat_min; + u32 vddat_max; + u32 sudat_min; + u32 l_min; + u32 h_min; +}; + +/** + * struct stm32f7_i2c_setup - private I2C timing setup parameters + * @speed_freq: I2C speed frequency (Hz) + * @clock_src: I2C clock source frequency (Hz) + * @rise_time: Rise time (ns) + * @fall_time: Fall time (ns) + * @fmp_clr_offset: Fast Mode Plus clear register offset from set register + */ +struct stm32f7_i2c_setup { + u32 speed_freq; + u32 clock_src; + u32 rise_time; + u32 fall_time; + u32 fmp_clr_offset; +}; + +/** + * struct stm32f7_i2c_timings - private I2C output parameters + * @node: List entry + * @presc: Prescaler value + * @scldel: Data setup time + * @sdadel: Data hold time + * @sclh: SCL high period (master mode) + * @scll: SCL low period (master mode) + */ +struct stm32f7_i2c_timings { + struct list_head node; + u8 presc; + u8 scldel; + u8 sdadel; + u8 sclh; + u8 scll; +}; + +/** + * struct stm32f7_i2c_msg - client specific data + * @addr: 8-bit or 10-bit slave addr, including r/w bit + * @count: number of bytes to be transferred + * @buf: data buffer + * @result: result of the transfer + * @stop: last I2C msg to be sent, i.e. STOP to be generated + * @smbus: boolean to know if the I2C IP is used in SMBus mode + * @size: type of SMBus protocol + * @read_write: direction of SMBus protocol + * SMBus block read and SMBus block write - block read process call protocols + * @smbus_buf: buffer to be used for SMBus protocol transfer. It will + * contain a maximum of 32 bytes of data + byte command + byte count + PEC + * This buffer has to be 32-bit aligned to be compliant with memory address + * register in DMA mode. + */ +struct stm32f7_i2c_msg { + u16 addr; + u32 count; + u8 *buf; + int result; + bool stop; + bool smbus; + int size; + char read_write; + u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4); +}; + +/** + * struct stm32f7_i2c_alert - SMBus alert specific data + * @setup: platform data for the smbus_alert i2c client + * @ara: I2C slave device used to respond to the SMBus Alert with Alert + * Response Address + */ +struct stm32f7_i2c_alert { + struct i2c_smbus_alert_setup setup; + struct i2c_client *ara; +}; + +/** + * struct stm32f7_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 + * @clk: hw i2c clock + * @bus_rate: I2C clock frequency of the controller + * @msg: Pointer to data to be written + * @msg_num: number of I2C messages to be executed + * @msg_id: message identifiant + * @f7_msg: customized i2c msg for driver usage + * @setup: I2C timing input setup + * @timing: I2C computed timings + * @slave: list of slave devices registered on the I2C bus + * @slave_running: slave device currently used + * @backup_regs: backup of i2c controller registers (for suspend/resume) + * @slave_dir: transfer direction for the current slave device + * @master_mode: boolean to know in which mode the I2C is running (master or + * slave) + * @dma: dma data + * @use_dma: boolean to know if dma is used in the current transfer + * @regmap: holds SYSCFG phandle for Fast Mode Plus bits + * @fmp_sreg: register address for setting Fast Mode Plus bits + * @fmp_creg: register address for clearing Fast Mode Plus bits + * @fmp_mask: mask for Fast Mode Plus bits in set register + * @wakeup_src: boolean to know if the device is a wakeup source + * @smbus_mode: states that the controller is configured in SMBus mode + * @host_notify_client: SMBus host-notify client + * @analog_filter: boolean to indicate enabling of the analog filter + * @dnf_dt: value of digital filter requested via dt + * @dnf: value of digital filter to apply + * @alert: SMBus alert specific data + */ +struct stm32f7_i2c_dev { + struct i2c_adapter adap; + struct device *dev; + void __iomem *base; + struct completion complete; + struct clk *clk; + unsigned int bus_rate; + struct i2c_msg *msg; + unsigned int msg_num; + unsigned int msg_id; + struct stm32f7_i2c_msg f7_msg; + struct stm32f7_i2c_setup setup; + struct stm32f7_i2c_timings timing; + struct i2c_client *slave[STM32F7_I2C_MAX_SLAVE]; + struct i2c_client *slave_running; + struct stm32f7_i2c_regs backup_regs; + u32 slave_dir; + bool master_mode; + struct stm32_i2c_dma *dma; + bool use_dma; + struct regmap *regmap; + u32 fmp_sreg; + u32 fmp_creg; + u32 fmp_mask; + bool wakeup_src; + bool smbus_mode; + struct i2c_client *host_notify_client; + bool analog_filter; + u32 dnf_dt; + u32 dnf; + struct stm32f7_i2c_alert *alert; +}; + +/* + * All these values are coming from I2C Specification, Version 6.0, 4th of + * April 2014. + * + * Table10. Characteristics of the SDA and SCL bus lines for Standard, Fast, + * and Fast-mode Plus I2C-bus devices + */ +static struct stm32f7_i2c_spec stm32f7_i2c_specs[] = { + { + .rate = I2C_MAX_STANDARD_MODE_FREQ, + .fall_max = 300, + .rise_max = 1000, + .hddat_min = 0, + .vddat_max = 3450, + .sudat_min = 250, + .l_min = 4700, + .h_min = 4000, + }, + { + .rate = I2C_MAX_FAST_MODE_FREQ, + .fall_max = 300, + .rise_max = 300, + .hddat_min = 0, + .vddat_max = 900, + .sudat_min = 100, + .l_min = 1300, + .h_min = 600, + }, + { + .rate = I2C_MAX_FAST_MODE_PLUS_FREQ, + .fall_max = 100, + .rise_max = 120, + .hddat_min = 0, + .vddat_max = 450, + .sudat_min = 50, + .l_min = 500, + .h_min = 260, + }, +}; + +static const struct stm32f7_i2c_setup stm32f7_setup = { + .rise_time = STM32F7_I2C_RISE_TIME_DEFAULT, + .fall_time = STM32F7_I2C_FALL_TIME_DEFAULT, +}; + +static const struct stm32f7_i2c_setup stm32mp15_setup = { + .rise_time = STM32F7_I2C_RISE_TIME_DEFAULT, + .fall_time = STM32F7_I2C_FALL_TIME_DEFAULT, + .fmp_clr_offset = 0x40, +}; + +static const struct stm32f7_i2c_setup stm32mp13_setup = { + .rise_time = STM32F7_I2C_RISE_TIME_DEFAULT, + .fall_time = STM32F7_I2C_FALL_TIME_DEFAULT, + .fmp_clr_offset = 0x4, +}; + +static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask) +{ + writel_relaxed(readl_relaxed(reg) | mask, reg); +} + +static inline void stm32f7_i2c_clr_bits(void __iomem *reg, u32 mask) +{ + writel_relaxed(readl_relaxed(reg) & ~mask, reg); +} + +static void stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev *i2c_dev, u32 mask) +{ + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, mask); +} + +static struct stm32f7_i2c_spec *stm32f7_get_specs(u32 rate) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(stm32f7_i2c_specs); i++) + if (rate <= stm32f7_i2c_specs[i].rate) + return &stm32f7_i2c_specs[i]; + + return ERR_PTR(-EINVAL); +} + +#define RATE_MIN(rate) ((rate) * 8 / 10) +static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev, + struct stm32f7_i2c_setup *setup, + struct stm32f7_i2c_timings *output) +{ + struct stm32f7_i2c_spec *specs; + u32 p_prev = STM32F7_PRESC_MAX; + u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC, + setup->clock_src); + u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC, + setup->speed_freq); + u32 clk_error_prev = i2cbus; + u32 tsync; + u32 af_delay_min, af_delay_max; + u32 dnf_delay; + u32 clk_min, clk_max; + int sdadel_min, sdadel_max; + int scldel_min; + struct stm32f7_i2c_timings *v, *_v, *s; + struct list_head solutions; + u16 p, l, a, h; + int ret = 0; + + specs = stm32f7_get_specs(setup->speed_freq); + if (specs == ERR_PTR(-EINVAL)) { + dev_err(i2c_dev->dev, "speed out of bound {%d}\n", + setup->speed_freq); + return -EINVAL; + } + + if ((setup->rise_time > specs->rise_max) || + (setup->fall_time > specs->fall_max)) { + dev_err(i2c_dev->dev, + "timings out of bound Rise{%d>%d}/Fall{%d>%d}\n", + setup->rise_time, specs->rise_max, + setup->fall_time, specs->fall_max); + return -EINVAL; + } + + i2c_dev->dnf = DIV_ROUND_CLOSEST(i2c_dev->dnf_dt, i2cclk); + if (i2c_dev->dnf > STM32F7_I2C_DNF_MAX) { + dev_err(i2c_dev->dev, + "DNF out of bound %d/%d\n", + i2c_dev->dnf * i2cclk, STM32F7_I2C_DNF_MAX * i2cclk); + return -EINVAL; + } + + /* Analog and Digital Filters */ + af_delay_min = + (i2c_dev->analog_filter ? + STM32F7_I2C_ANALOG_FILTER_DELAY_MIN : 0); + af_delay_max = + (i2c_dev->analog_filter ? + STM32F7_I2C_ANALOG_FILTER_DELAY_MAX : 0); + dnf_delay = i2c_dev->dnf * i2cclk; + + sdadel_min = specs->hddat_min + setup->fall_time - + af_delay_min - (i2c_dev->dnf + 3) * i2cclk; + + sdadel_max = specs->vddat_max - setup->rise_time - + af_delay_max - (i2c_dev->dnf + 4) * i2cclk; + + scldel_min = setup->rise_time + specs->sudat_min; + + if (sdadel_min < 0) + sdadel_min = 0; + if (sdadel_max < 0) + sdadel_max = 0; + + dev_dbg(i2c_dev->dev, "SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n", + sdadel_min, sdadel_max, scldel_min); + + INIT_LIST_HEAD(&solutions); + /* Compute possible values for PRESC, SCLDEL and SDADEL */ + for (p = 0; p < STM32F7_PRESC_MAX; p++) { + for (l = 0; l < STM32F7_SCLDEL_MAX; l++) { + u32 scldel = (l + 1) * (p + 1) * i2cclk; + + if (scldel < scldel_min) + continue; + + for (a = 0; a < STM32F7_SDADEL_MAX; a++) { + u32 sdadel = (a * (p + 1) + 1) * i2cclk; + + if (((sdadel >= sdadel_min) && + (sdadel <= sdadel_max)) && + (p != p_prev)) { + v = kmalloc(sizeof(*v), GFP_KERNEL); + if (!v) { + ret = -ENOMEM; + goto exit; + } + + v->presc = p; + v->scldel = l; + v->sdadel = a; + p_prev = p; + + list_add_tail(&v->node, + &solutions); + break; + } + } + + if (p_prev == p) + break; + } + } + + if (list_empty(&solutions)) { + dev_err(i2c_dev->dev, "no Prescaler solution\n"); + ret = -EPERM; + goto exit; + } + + tsync = af_delay_min + dnf_delay + (2 * i2cclk); + s = NULL; + clk_max = NSEC_PER_SEC / RATE_MIN(setup->speed_freq); + clk_min = NSEC_PER_SEC / setup->speed_freq; + + /* + * Among Prescaler possibilities discovered above figures out SCL Low + * and High Period. Provided: + * - SCL Low Period has to be higher than SCL Clock Low Period + * defined by I2C Specification. I2C Clock has to be lower than + * (SCL Low Period - Analog/Digital filters) / 4. + * - SCL High Period has to be lower than SCL Clock High Period + * defined by I2C Specification + * - I2C Clock has to be lower than SCL High Period + */ + list_for_each_entry(v, &solutions, node) { + u32 prescaler = (v->presc + 1) * i2cclk; + + for (l = 0; l < STM32F7_SCLL_MAX; l++) { + u32 tscl_l = (l + 1) * prescaler + tsync; + + if ((tscl_l < specs->l_min) || + (i2cclk >= + ((tscl_l - af_delay_min - dnf_delay) / 4))) { + continue; + } + + for (h = 0; h < STM32F7_SCLH_MAX; h++) { + u32 tscl_h = (h + 1) * prescaler + tsync; + u32 tscl = tscl_l + tscl_h + + setup->rise_time + setup->fall_time; + + if ((tscl >= clk_min) && (tscl <= clk_max) && + (tscl_h >= specs->h_min) && + (i2cclk < tscl_h)) { + int clk_error = tscl - i2cbus; + + if (clk_error < 0) + clk_error = -clk_error; + + if (clk_error < clk_error_prev) { + clk_error_prev = clk_error; + v->scll = l; + v->sclh = h; + s = v; + } + } + } + } + } + + if (!s) { + dev_err(i2c_dev->dev, "no solution at all\n"); + ret = -EPERM; + goto exit; + } + + output->presc = s->presc; + output->scldel = s->scldel; + output->sdadel = s->sdadel; + output->scll = s->scll; + output->sclh = s->sclh; + + dev_dbg(i2c_dev->dev, + "Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n", + output->presc, + output->scldel, output->sdadel, + output->scll, output->sclh); + +exit: + /* Release list and memory */ + list_for_each_entry_safe(v, _v, &solutions, node) { + list_del(&v->node); + kfree(v); + } + + return ret; +} + +static u32 stm32f7_get_lower_rate(u32 rate) +{ + int i = ARRAY_SIZE(stm32f7_i2c_specs); + + while (--i) + if (stm32f7_i2c_specs[i].rate < rate) + break; + + return stm32f7_i2c_specs[i].rate; +} + +static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev, + struct stm32f7_i2c_setup *setup) +{ + struct i2c_timings timings, *t = &timings; + int ret = 0; + + t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ; + t->scl_rise_ns = i2c_dev->setup.rise_time; + t->scl_fall_ns = i2c_dev->setup.fall_time; + + i2c_parse_fw_timings(i2c_dev->dev, t, false); + + if (t->bus_freq_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) { + dev_err(i2c_dev->dev, "Invalid bus speed (%i>%i)\n", + t->bus_freq_hz, I2C_MAX_FAST_MODE_PLUS_FREQ); + return -EINVAL; + } + + setup->speed_freq = t->bus_freq_hz; + i2c_dev->setup.rise_time = t->scl_rise_ns; + i2c_dev->setup.fall_time = t->scl_fall_ns; + i2c_dev->dnf_dt = t->digital_filter_width_ns; + setup->clock_src = clk_get_rate(i2c_dev->clk); + + if (!setup->clock_src) { + dev_err(i2c_dev->dev, "clock rate is 0\n"); + return -EINVAL; + } + + if (!of_property_read_bool(i2c_dev->dev->of_node, "i2c-digital-filter")) + i2c_dev->dnf_dt = STM32F7_I2C_DNF_DEFAULT; + + do { + ret = stm32f7_i2c_compute_timing(i2c_dev, setup, + &i2c_dev->timing); + if (ret) { + dev_err(i2c_dev->dev, + "failed to compute I2C timings.\n"); + if (setup->speed_freq <= I2C_MAX_STANDARD_MODE_FREQ) + break; + setup->speed_freq = + stm32f7_get_lower_rate(setup->speed_freq); + dev_warn(i2c_dev->dev, + "downgrade I2C Speed Freq to (%i)\n", + setup->speed_freq); + } + } while (ret); + + if (ret) { + dev_err(i2c_dev->dev, "Impossible to compute I2C timings.\n"); + return ret; + } + + i2c_dev->analog_filter = of_property_read_bool(i2c_dev->dev->of_node, + "i2c-analog-filter"); + + dev_dbg(i2c_dev->dev, "I2C Speed(%i), Clk Source(%i)\n", + setup->speed_freq, setup->clock_src); + dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n", + setup->rise_time, setup->fall_time); + dev_dbg(i2c_dev->dev, "I2C Analog Filter(%s), DNF(%i)\n", + (i2c_dev->analog_filter ? "On" : "Off"), i2c_dev->dnf); + + i2c_dev->bus_rate = setup->speed_freq; + + return 0; +} + +static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev) +{ + void __iomem *base = i2c_dev->base; + u32 mask = STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN; + + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask); +} + +static void stm32f7_i2c_dma_callback(void *arg) +{ + struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + struct device *dev = dma->chan_using->device->dev; + + stm32f7_i2c_disable_dma_req(i2c_dev); + dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir); + complete(&dma->dma_complete); +} + +static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_timings *t = &i2c_dev->timing; + u32 timing = 0; + + /* Timing settings */ + timing |= STM32F7_I2C_TIMINGR_PRESC(t->presc); + timing |= STM32F7_I2C_TIMINGR_SCLDEL(t->scldel); + timing |= STM32F7_I2C_TIMINGR_SDADEL(t->sdadel); + timing |= STM32F7_I2C_TIMINGR_SCLH(t->sclh); + timing |= STM32F7_I2C_TIMINGR_SCLL(t->scll); + writel_relaxed(timing, i2c_dev->base + STM32F7_I2C_TIMINGR); + + /* Configure the Analog Filter */ + if (i2c_dev->analog_filter) + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_ANFOFF); + else + stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_ANFOFF); + + /* Program the Digital Filter */ + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_DNF_MASK); + stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_DNF(i2c_dev->dnf)); + + stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_PE); +} + +static void stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + void __iomem *base = i2c_dev->base; + + if (f7_msg->count) { + writeb_relaxed(*f7_msg->buf++, base + STM32F7_I2C_TXDR); + f7_msg->count--; + } +} + +static void stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + void __iomem *base = i2c_dev->base; + + if (f7_msg->count) { + *f7_msg->buf++ = readb_relaxed(base + STM32F7_I2C_RXDR); + f7_msg->count--; + } else { + /* Flush RX buffer has no data is expected */ + readb_relaxed(base + STM32F7_I2C_RXDR); + } +} + +static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + u32 cr2; + + if (i2c_dev->use_dma) + f7_msg->count -= STM32F7_I2C_MAX_LEN; + + cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2); + + cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK; + if (f7_msg->count > STM32F7_I2C_MAX_LEN) { + cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN); + } else { + cr2 &= ~STM32F7_I2C_CR2_RELOAD; + cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count); + } + + writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); +} + +static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + u32 cr2; + u8 *val; + + /* + * For I2C_SMBUS_BLOCK_DATA && I2C_SMBUS_BLOCK_PROC_CALL, the first + * data received inform us how many data will follow. + */ + stm32f7_i2c_read_rx_data(i2c_dev); + + /* + * Update NBYTES with the value read to continue the transfer + */ + val = f7_msg->buf - sizeof(u8); + f7_msg->count = *val; + cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2); + cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD); + cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count); + writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); +} + +static void stm32f7_i2c_release_bus(struct i2c_adapter *i2c_adap) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); + + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_PE); + + stm32f7_i2c_hw_config(i2c_dev); +} + +static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) +{ + u32 status; + int ret; + + ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F7_I2C_ISR, + status, + !(status & STM32F7_I2C_ISR_BUSY), + 10, 1000); + if (!ret) + return 0; + + stm32f7_i2c_release_bus(&i2c_dev->adap); + + return -EBUSY; +} + +static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, + struct i2c_msg *msg) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + void __iomem *base = i2c_dev->base; + u32 cr1, cr2; + int ret; + + f7_msg->addr = msg->addr; + f7_msg->buf = msg->buf; + f7_msg->count = msg->len; + f7_msg->result = 0; + f7_msg->stop = (i2c_dev->msg_id >= i2c_dev->msg_num - 1); + + reinit_completion(&i2c_dev->complete); + + cr1 = readl_relaxed(base + STM32F7_I2C_CR1); + cr2 = readl_relaxed(base + STM32F7_I2C_CR2); + + /* Set transfer direction */ + cr2 &= ~STM32F7_I2C_CR2_RD_WRN; + if (msg->flags & I2C_M_RD) + cr2 |= STM32F7_I2C_CR2_RD_WRN; + + /* Set slave address */ + cr2 &= ~(STM32F7_I2C_CR2_HEAD10R | STM32F7_I2C_CR2_ADD10); + if (msg->flags & I2C_M_TEN) { + cr2 &= ~STM32F7_I2C_CR2_SADD10_MASK; + cr2 |= STM32F7_I2C_CR2_SADD10(f7_msg->addr); + cr2 |= STM32F7_I2C_CR2_ADD10; + } else { + cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK; + cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr); + } + + /* Set nb bytes to transfer and reload if needed */ + cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD); + if (f7_msg->count > STM32F7_I2C_MAX_LEN) { + cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN); + cr2 |= STM32F7_I2C_CR2_RELOAD; + } else { + cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count); + } + + /* Enable NACK, STOP, error and transfer complete interrupts */ + cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE | + STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE; + + /* Clear DMA req and TX/RX interrupt */ + cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE | + STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN); + + /* Configure DMA or enable RX/TX interrupt */ + i2c_dev->use_dma = false; + if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) { + ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, + msg->flags & I2C_M_RD, + f7_msg->count, f7_msg->buf, + stm32f7_i2c_dma_callback, + i2c_dev); + if (!ret) + i2c_dev->use_dma = true; + else + dev_warn(i2c_dev->dev, "can't use DMA\n"); + } + + if (!i2c_dev->use_dma) { + if (msg->flags & I2C_M_RD) + cr1 |= STM32F7_I2C_CR1_RXIE; + else + cr1 |= STM32F7_I2C_CR1_TXIE; + } else { + if (msg->flags & I2C_M_RD) + cr1 |= STM32F7_I2C_CR1_RXDMAEN; + else + cr1 |= STM32F7_I2C_CR1_TXDMAEN; + } + + /* Configure Start/Repeated Start */ + cr2 |= STM32F7_I2C_CR2_START; + + i2c_dev->master_mode = true; + + /* Write configurations registers */ + writel_relaxed(cr1, base + STM32F7_I2C_CR1); + writel_relaxed(cr2, base + STM32F7_I2C_CR2); +} + +static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, + unsigned short flags, u8 command, + union i2c_smbus_data *data) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct device *dev = i2c_dev->dev; + void __iomem *base = i2c_dev->base; + u32 cr1, cr2; + int i, ret; + + f7_msg->result = 0; + reinit_completion(&i2c_dev->complete); + + cr2 = readl_relaxed(base + STM32F7_I2C_CR2); + cr1 = readl_relaxed(base + STM32F7_I2C_CR1); + + /* Set transfer direction */ + cr2 &= ~STM32F7_I2C_CR2_RD_WRN; + if (f7_msg->read_write) + cr2 |= STM32F7_I2C_CR2_RD_WRN; + + /* Set slave address */ + cr2 &= ~(STM32F7_I2C_CR2_ADD10 | STM32F7_I2C_CR2_SADD7_MASK); + cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr); + + f7_msg->smbus_buf[0] = command; + switch (f7_msg->size) { + case I2C_SMBUS_QUICK: + f7_msg->stop = true; + f7_msg->count = 0; + break; + case I2C_SMBUS_BYTE: + f7_msg->stop = true; + f7_msg->count = 1; + break; + case I2C_SMBUS_BYTE_DATA: + if (f7_msg->read_write) { + f7_msg->stop = false; + f7_msg->count = 1; + cr2 &= ~STM32F7_I2C_CR2_RD_WRN; + } else { + f7_msg->stop = true; + f7_msg->count = 2; + f7_msg->smbus_buf[1] = data->byte; + } + break; + case I2C_SMBUS_WORD_DATA: + if (f7_msg->read_write) { + f7_msg->stop = false; + f7_msg->count = 1; + cr2 &= ~STM32F7_I2C_CR2_RD_WRN; + } else { + f7_msg->stop = true; + f7_msg->count = 3; + f7_msg->smbus_buf[1] = data->word & 0xff; + f7_msg->smbus_buf[2] = data->word >> 8; + } + break; + case I2C_SMBUS_BLOCK_DATA: + if (f7_msg->read_write) { + f7_msg->stop = false; + f7_msg->count = 1; + cr2 &= ~STM32F7_I2C_CR2_RD_WRN; + } else { + f7_msg->stop = true; + if (data->block[0] > I2C_SMBUS_BLOCK_MAX || + !data->block[0]) { + dev_err(dev, "Invalid block write size %d\n", + data->block[0]); + return -EINVAL; + } + f7_msg->count = data->block[0] + 2; + for (i = 1; i < f7_msg->count; i++) + f7_msg->smbus_buf[i] = data->block[i - 1]; + } + break; + case I2C_SMBUS_PROC_CALL: + f7_msg->stop = false; + f7_msg->count = 3; + f7_msg->smbus_buf[1] = data->word & 0xff; + f7_msg->smbus_buf[2] = data->word >> 8; + cr2 &= ~STM32F7_I2C_CR2_RD_WRN; + f7_msg->read_write = I2C_SMBUS_READ; + break; + case I2C_SMBUS_BLOCK_PROC_CALL: + f7_msg->stop = false; + if (data->block[0] > I2C_SMBUS_BLOCK_MAX - 1) { + dev_err(dev, "Invalid block write size %d\n", + data->block[0]); + return -EINVAL; + } + f7_msg->count = data->block[0] + 2; + for (i = 1; i < f7_msg->count; i++) + f7_msg->smbus_buf[i] = data->block[i - 1]; + cr2 &= ~STM32F7_I2C_CR2_RD_WRN; + f7_msg->read_write = I2C_SMBUS_READ; + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + /* Rely on emulated i2c transfer (through master_xfer) */ + return -EOPNOTSUPP; + default: + dev_err(dev, "Unsupported smbus protocol %d\n", f7_msg->size); + return -EOPNOTSUPP; + } + + f7_msg->buf = f7_msg->smbus_buf; + + /* Configure PEC */ + if ((flags & I2C_CLIENT_PEC) && f7_msg->size != I2C_SMBUS_QUICK) { + cr1 |= STM32F7_I2C_CR1_PECEN; + if (!f7_msg->read_write) { + cr2 |= STM32F7_I2C_CR2_PECBYTE; + f7_msg->count++; + } + } else { + cr1 &= ~STM32F7_I2C_CR1_PECEN; + cr2 &= ~STM32F7_I2C_CR2_PECBYTE; + } + + /* Set number of bytes to be transferred */ + cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD); + cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count); + + /* Enable NACK, STOP, error and transfer complete interrupts */ + cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE | + STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE; + + /* Clear DMA req and TX/RX interrupt */ + cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE | + STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN); + + /* Configure DMA or enable RX/TX interrupt */ + i2c_dev->use_dma = false; + if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) { + ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, + cr2 & STM32F7_I2C_CR2_RD_WRN, + f7_msg->count, f7_msg->buf, + stm32f7_i2c_dma_callback, + i2c_dev); + if (!ret) + i2c_dev->use_dma = true; + else + dev_warn(i2c_dev->dev, "can't use DMA\n"); + } + + if (!i2c_dev->use_dma) { + if (cr2 & STM32F7_I2C_CR2_RD_WRN) + cr1 |= STM32F7_I2C_CR1_RXIE; + else + cr1 |= STM32F7_I2C_CR1_TXIE; + } else { + if (cr2 & STM32F7_I2C_CR2_RD_WRN) + cr1 |= STM32F7_I2C_CR1_RXDMAEN; + else + cr1 |= STM32F7_I2C_CR1_TXDMAEN; + } + + /* Set Start bit */ + cr2 |= STM32F7_I2C_CR2_START; + + i2c_dev->master_mode = true; + + /* Write configurations registers */ + writel_relaxed(cr1, base + STM32F7_I2C_CR1); + writel_relaxed(cr2, base + STM32F7_I2C_CR2); + + return 0; +} + +static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + void __iomem *base = i2c_dev->base; + u32 cr1, cr2; + int ret; + + cr2 = readl_relaxed(base + STM32F7_I2C_CR2); + cr1 = readl_relaxed(base + STM32F7_I2C_CR1); + + /* Set transfer direction */ + cr2 |= STM32F7_I2C_CR2_RD_WRN; + + switch (f7_msg->size) { + case I2C_SMBUS_BYTE_DATA: + f7_msg->count = 1; + break; + case I2C_SMBUS_WORD_DATA: + case I2C_SMBUS_PROC_CALL: + f7_msg->count = 2; + break; + case I2C_SMBUS_BLOCK_DATA: + case I2C_SMBUS_BLOCK_PROC_CALL: + f7_msg->count = 1; + cr2 |= STM32F7_I2C_CR2_RELOAD; + break; + } + + f7_msg->buf = f7_msg->smbus_buf; + f7_msg->stop = true; + + /* Add one byte for PEC if needed */ + if (cr1 & STM32F7_I2C_CR1_PECEN) { + cr2 |= STM32F7_I2C_CR2_PECBYTE; + f7_msg->count++; + } + + /* Set number of bytes to be transferred */ + cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK); + cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count); + + /* + * Configure RX/TX interrupt: + */ + cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE); + cr1 |= STM32F7_I2C_CR1_RXIE; + + /* + * Configure DMA or enable RX/TX interrupt: + * For I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_BLOCK_PROC_CALL we don't use + * dma as we don't know in advance how many data will be received + */ + cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE | + STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN); + + i2c_dev->use_dma = false; + if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN && + f7_msg->size != I2C_SMBUS_BLOCK_DATA && + f7_msg->size != I2C_SMBUS_BLOCK_PROC_CALL) { + ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma, + cr2 & STM32F7_I2C_CR2_RD_WRN, + f7_msg->count, f7_msg->buf, + stm32f7_i2c_dma_callback, + i2c_dev); + + if (!ret) + i2c_dev->use_dma = true; + else + dev_warn(i2c_dev->dev, "can't use DMA\n"); + } + + if (!i2c_dev->use_dma) + cr1 |= STM32F7_I2C_CR1_RXIE; + else + cr1 |= STM32F7_I2C_CR1_RXDMAEN; + + /* Configure Repeated Start */ + cr2 |= STM32F7_I2C_CR2_START; + + /* Write configurations registers */ + writel_relaxed(cr1, base + STM32F7_I2C_CR1); + writel_relaxed(cr2, base + STM32F7_I2C_CR2); +} + +static int stm32f7_i2c_smbus_check_pec(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + u8 count, internal_pec, received_pec; + + internal_pec = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR); + + switch (f7_msg->size) { + case I2C_SMBUS_BYTE: + case I2C_SMBUS_BYTE_DATA: + received_pec = f7_msg->smbus_buf[1]; + break; + case I2C_SMBUS_WORD_DATA: + case I2C_SMBUS_PROC_CALL: + received_pec = f7_msg->smbus_buf[2]; + break; + case I2C_SMBUS_BLOCK_DATA: + case I2C_SMBUS_BLOCK_PROC_CALL: + count = f7_msg->smbus_buf[0]; + received_pec = f7_msg->smbus_buf[count]; + break; + default: + dev_err(i2c_dev->dev, "Unsupported smbus protocol for PEC\n"); + return -EINVAL; + } + + if (internal_pec != received_pec) { + dev_err(i2c_dev->dev, "Bad PEC 0x%02x vs. 0x%02x\n", + internal_pec, received_pec); + return -EBADMSG; + } + + return 0; +} + +static bool stm32f7_i2c_is_addr_match(struct i2c_client *slave, u32 addcode) +{ + u32 addr; + + if (!slave) + return false; + + if (slave->flags & I2C_CLIENT_TEN) { + /* + * For 10-bit addr, addcode = 11110XY with + * X = Bit 9 of slave address + * Y = Bit 8 of slave address + */ + addr = slave->addr >> 8; + addr |= 0x78; + if (addr == addcode) + return true; + } else { + addr = slave->addr & 0x7f; + if (addr == addcode) + return true; + } + + return false; +} + +static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev) +{ + struct i2c_client *slave = i2c_dev->slave_running; + void __iomem *base = i2c_dev->base; + u32 mask; + u8 value = 0; + + if (i2c_dev->slave_dir) { + /* Notify i2c slave that new read transfer is starting */ + i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value); + + /* + * Disable slave TX config in case of I2C combined message + * (I2C Write followed by I2C Read) + */ + mask = STM32F7_I2C_CR2_RELOAD; + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, mask); + mask = STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE | + STM32F7_I2C_CR1_TCIE; + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask); + + /* Enable TX empty, STOP, NACK interrupts */ + mask = STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE | + STM32F7_I2C_CR1_TXIE; + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask); + + /* Write 1st data byte */ + writel_relaxed(value, base + STM32F7_I2C_TXDR); + } else { + /* Notify i2c slave that new write transfer is starting */ + i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); + + /* Set reload mode to be able to ACK/NACK each received byte */ + mask = STM32F7_I2C_CR2_RELOAD; + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask); + + /* + * Set STOP, NACK, RX empty and transfer complete interrupts.* + * Set Slave Byte Control to be able to ACK/NACK each data + * byte received + */ + mask = STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE | + STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE | + STM32F7_I2C_CR1_TCIE; + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask); + } +} + +static void stm32f7_i2c_slave_addr(struct stm32f7_i2c_dev *i2c_dev) +{ + void __iomem *base = i2c_dev->base; + u32 isr, addcode, dir, mask; + int i; + + isr = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + addcode = STM32F7_I2C_ISR_ADDCODE_GET(isr); + dir = isr & STM32F7_I2C_ISR_DIR; + + for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) { + if (stm32f7_i2c_is_addr_match(i2c_dev->slave[i], addcode)) { + i2c_dev->slave_running = i2c_dev->slave[i]; + i2c_dev->slave_dir = dir; + + /* Start I2C slave processing */ + stm32f7_i2c_slave_start(i2c_dev); + + /* Clear ADDR flag */ + mask = STM32F7_I2C_ICR_ADDRCF; + writel_relaxed(mask, base + STM32F7_I2C_ICR); + break; + } + } +} + +static int stm32f7_i2c_get_slave_id(struct stm32f7_i2c_dev *i2c_dev, + struct i2c_client *slave, int *id) +{ + int i; + + for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) { + if (i2c_dev->slave[i] == slave) { + *id = i; + return 0; + } + } + + dev_err(i2c_dev->dev, "Slave 0x%x not registered\n", slave->addr); + + return -ENODEV; +} + +static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev, + struct i2c_client *slave, int *id) +{ + struct device *dev = i2c_dev->dev; + int i; + + /* + * slave[STM32F7_SLAVE_HOSTNOTIFY] support only SMBus Host address (0x8) + * slave[STM32F7_SLAVE_7_10_BITS_ADDR] supports 7-bit and 10-bit slave address + * slave[STM32F7_SLAVE_7_BITS_ADDR] supports 7-bit slave address only + */ + if (i2c_dev->smbus_mode && (slave->addr == 0x08)) { + if (i2c_dev->slave[STM32F7_SLAVE_HOSTNOTIFY]) + goto fail; + *id = STM32F7_SLAVE_HOSTNOTIFY; + return 0; + } + + for (i = STM32F7_I2C_MAX_SLAVE - 1; i > STM32F7_SLAVE_HOSTNOTIFY; i--) { + if ((i == STM32F7_SLAVE_7_BITS_ADDR) && + (slave->flags & I2C_CLIENT_TEN)) + continue; + if (!i2c_dev->slave[i]) { + *id = i; + return 0; + } + } + +fail: + dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr); + + return -EINVAL; +} + +static bool stm32f7_i2c_is_slave_registered(struct stm32f7_i2c_dev *i2c_dev) +{ + int i; + + for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) { + if (i2c_dev->slave[i]) + return true; + } + + return false; +} + +static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev) +{ + int i, busy; + + busy = 0; + for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) { + if (i2c_dev->slave[i]) + busy++; + } + + return i == busy; +} + +static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev) +{ + void __iomem *base = i2c_dev->base; + u32 cr2, status, mask; + u8 val; + int ret; + + status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + + /* Slave transmitter mode */ + if (status & STM32F7_I2C_ISR_TXIS) { + i2c_slave_event(i2c_dev->slave_running, + I2C_SLAVE_READ_PROCESSED, + &val); + + /* Write data byte */ + writel_relaxed(val, base + STM32F7_I2C_TXDR); + } + + /* Transfer Complete Reload for Slave receiver mode */ + if (status & STM32F7_I2C_ISR_TCR || status & STM32F7_I2C_ISR_RXNE) { + /* + * Read data byte then set NBYTES to receive next byte or NACK + * the current received byte + */ + val = readb_relaxed(i2c_dev->base + STM32F7_I2C_RXDR); + ret = i2c_slave_event(i2c_dev->slave_running, + I2C_SLAVE_WRITE_RECEIVED, + &val); + if (!ret) { + cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2); + cr2 |= STM32F7_I2C_CR2_NBYTES(1); + writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); + } else { + mask = STM32F7_I2C_CR2_NACK; + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask); + } + } + + /* NACK received */ + if (status & STM32F7_I2C_ISR_NACKF) { + dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__); + writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR); + } + + /* STOP received */ + if (status & STM32F7_I2C_ISR_STOPF) { + /* Disable interrupts */ + stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_XFER_IRQ_MASK); + + if (i2c_dev->slave_dir) { + /* + * Flush TX buffer in order to not used the byte in + * TXDR for the next transfer + */ + mask = STM32F7_I2C_ISR_TXE; + stm32f7_i2c_set_bits(base + STM32F7_I2C_ISR, mask); + } + + /* Clear STOP flag */ + writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR); + + /* Notify i2c slave that a STOP flag has been detected */ + i2c_slave_event(i2c_dev->slave_running, I2C_SLAVE_STOP, &val); + + i2c_dev->slave_running = NULL; + } + + /* Address match received */ + if (status & STM32F7_I2C_ISR_ADDR) + stm32f7_i2c_slave_addr(i2c_dev); + + return IRQ_HANDLED; +} + +static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) +{ + struct stm32f7_i2c_dev *i2c_dev = data; + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + void __iomem *base = i2c_dev->base; + u32 status, mask; + int ret = IRQ_HANDLED; + + /* Check if the interrupt if for a slave device */ + if (!i2c_dev->master_mode) { + ret = stm32f7_i2c_slave_isr_event(i2c_dev); + return ret; + } + + status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + + /* Tx empty */ + if (status & STM32F7_I2C_ISR_TXIS) + stm32f7_i2c_write_tx_data(i2c_dev); + + /* RX not empty */ + if (status & STM32F7_I2C_ISR_RXNE) + stm32f7_i2c_read_rx_data(i2c_dev); + + /* NACK received */ + if (status & STM32F7_I2C_ISR_NACKF) { + dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n", + __func__, f7_msg->addr); + writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR); + if (i2c_dev->use_dma) { + stm32f7_i2c_disable_dma_req(i2c_dev); + dmaengine_terminate_async(dma->chan_using); + } + f7_msg->result = -ENXIO; + } + + /* STOP detection flag */ + if (status & STM32F7_I2C_ISR_STOPF) { + /* Disable interrupts */ + if (stm32f7_i2c_is_slave_registered(i2c_dev)) + mask = STM32F7_I2C_XFER_IRQ_MASK; + else + mask = STM32F7_I2C_ALL_IRQ_MASK; + stm32f7_i2c_disable_irq(i2c_dev, mask); + + /* Clear STOP flag */ + writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR); + + if (i2c_dev->use_dma && !f7_msg->result) { + ret = IRQ_WAKE_THREAD; + } else { + i2c_dev->master_mode = false; + complete(&i2c_dev->complete); + } + } + + /* Transfer complete */ + if (status & STM32F7_I2C_ISR_TC) { + if (f7_msg->stop) { + mask = STM32F7_I2C_CR2_STOP; + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask); + } else if (i2c_dev->use_dma && !f7_msg->result) { + ret = IRQ_WAKE_THREAD; + } else if (f7_msg->smbus) { + stm32f7_i2c_smbus_rep_start(i2c_dev); + } else { + i2c_dev->msg_id++; + i2c_dev->msg++; + stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg); + } + } + + if (status & STM32F7_I2C_ISR_TCR) { + if (f7_msg->smbus) + stm32f7_i2c_smbus_reload(i2c_dev); + else + stm32f7_i2c_reload(i2c_dev); + } + + return ret; +} + +static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) +{ + struct stm32f7_i2c_dev *i2c_dev = data; + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + u32 status; + int ret; + + /* + * Wait for dma transfer completion before sending next message or + * notity the end of xfer to the client + */ + ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ); + if (!ret) { + dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__); + stm32f7_i2c_disable_dma_req(i2c_dev); + dmaengine_terminate_async(dma->chan_using); + f7_msg->result = -ETIMEDOUT; + } + + status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + + if (status & STM32F7_I2C_ISR_TC) { + if (f7_msg->smbus) { + stm32f7_i2c_smbus_rep_start(i2c_dev); + } else { + i2c_dev->msg_id++; + i2c_dev->msg++; + stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg); + } + } else { + i2c_dev->master_mode = false; + complete(&i2c_dev->complete); + } + + return IRQ_HANDLED; +} + +static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) +{ + struct stm32f7_i2c_dev *i2c_dev = data; + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + void __iomem *base = i2c_dev->base; + struct device *dev = i2c_dev->dev; + struct stm32_i2c_dma *dma = i2c_dev->dma; + u32 status; + + status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + + /* Bus error */ + if (status & STM32F7_I2C_ISR_BERR) { + dev_err(dev, "<%s>: Bus error accessing addr 0x%x\n", + __func__, f7_msg->addr); + writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR); + stm32f7_i2c_release_bus(&i2c_dev->adap); + f7_msg->result = -EIO; + } + + /* Arbitration loss */ + if (status & STM32F7_I2C_ISR_ARLO) { + dev_dbg(dev, "<%s>: Arbitration loss accessing addr 0x%x\n", + __func__, f7_msg->addr); + writel_relaxed(STM32F7_I2C_ICR_ARLOCF, base + STM32F7_I2C_ICR); + f7_msg->result = -EAGAIN; + } + + if (status & STM32F7_I2C_ISR_PECERR) { + dev_err(dev, "<%s>: PEC error in reception accessing addr 0x%x\n", + __func__, f7_msg->addr); + writel_relaxed(STM32F7_I2C_ICR_PECCF, base + STM32F7_I2C_ICR); + f7_msg->result = -EINVAL; + } + + if (status & STM32F7_I2C_ISR_ALERT) { + dev_dbg(dev, "<%s>: SMBus alert received\n", __func__); + writel_relaxed(STM32F7_I2C_ICR_ALERTCF, base + STM32F7_I2C_ICR); + i2c_handle_smbus_alert(i2c_dev->alert->ara); + return IRQ_HANDLED; + } + + if (!i2c_dev->slave_running) { + u32 mask; + /* Disable interrupts */ + if (stm32f7_i2c_is_slave_registered(i2c_dev)) + mask = STM32F7_I2C_XFER_IRQ_MASK; + else + mask = STM32F7_I2C_ALL_IRQ_MASK; + stm32f7_i2c_disable_irq(i2c_dev, mask); + } + + /* Disable dma */ + if (i2c_dev->use_dma) { + stm32f7_i2c_disable_dma_req(i2c_dev); + dmaengine_terminate_async(dma->chan_using); + } + + i2c_dev->master_mode = false; + complete(&i2c_dev->complete); + + return IRQ_HANDLED; +} + +static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap, + struct i2c_msg msgs[], int num) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + unsigned long time_left; + int ret; + + i2c_dev->msg = msgs; + i2c_dev->msg_num = num; + i2c_dev->msg_id = 0; + f7_msg->smbus = false; + + ret = pm_runtime_resume_and_get(i2c_dev->dev); + if (ret < 0) + return ret; + + ret = stm32f7_i2c_wait_free_bus(i2c_dev); + if (ret) + goto pm_free; + + stm32f7_i2c_xfer_msg(i2c_dev, msgs); + + time_left = wait_for_completion_timeout(&i2c_dev->complete, + i2c_dev->adap.timeout); + ret = f7_msg->result; + if (ret) { + if (i2c_dev->use_dma) + dmaengine_synchronize(dma->chan_using); + + /* + * It is possible that some unsent data have already been + * written into TXDR. To avoid sending old data in a + * further transfer, flush TXDR in case of any error + */ + writel_relaxed(STM32F7_I2C_ISR_TXE, + i2c_dev->base + STM32F7_I2C_ISR); + goto pm_free; + } + + if (!time_left) { + dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n", + i2c_dev->msg->addr); + if (i2c_dev->use_dma) + dmaengine_terminate_sync(dma->chan_using); + stm32f7_i2c_wait_free_bus(i2c_dev); + ret = -ETIMEDOUT; + } + +pm_free: + pm_runtime_mark_last_busy(i2c_dev->dev); + pm_runtime_put_autosuspend(i2c_dev->dev); + + return (ret < 0) ? ret : num; +} + +static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, + union i2c_smbus_data *data) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adapter); + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + struct device *dev = i2c_dev->dev; + unsigned long timeout; + int i, ret; + + f7_msg->addr = addr; + f7_msg->size = size; + f7_msg->read_write = read_write; + f7_msg->smbus = true; + + ret = pm_runtime_resume_and_get(dev); + if (ret < 0) + return ret; + + ret = stm32f7_i2c_wait_free_bus(i2c_dev); + if (ret) + goto pm_free; + + ret = stm32f7_i2c_smbus_xfer_msg(i2c_dev, flags, command, data); + if (ret) + goto pm_free; + + timeout = wait_for_completion_timeout(&i2c_dev->complete, + i2c_dev->adap.timeout); + ret = f7_msg->result; + if (ret) { + if (i2c_dev->use_dma) + dmaengine_synchronize(dma->chan_using); + + /* + * It is possible that some unsent data have already been + * written into TXDR. To avoid sending old data in a + * further transfer, flush TXDR in case of any error + */ + writel_relaxed(STM32F7_I2C_ISR_TXE, + i2c_dev->base + STM32F7_I2C_ISR); + goto pm_free; + } + + if (!timeout) { + dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr); + if (i2c_dev->use_dma) + dmaengine_terminate_sync(dma->chan_using); + stm32f7_i2c_wait_free_bus(i2c_dev); + ret = -ETIMEDOUT; + goto pm_free; + } + + /* Check PEC */ + if ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && read_write) { + ret = stm32f7_i2c_smbus_check_pec(i2c_dev); + if (ret) + goto pm_free; + } + + if (read_write && size != I2C_SMBUS_QUICK) { + switch (size) { + case I2C_SMBUS_BYTE: + case I2C_SMBUS_BYTE_DATA: + data->byte = f7_msg->smbus_buf[0]; + break; + case I2C_SMBUS_WORD_DATA: + case I2C_SMBUS_PROC_CALL: + data->word = f7_msg->smbus_buf[0] | + (f7_msg->smbus_buf[1] << 8); + break; + case I2C_SMBUS_BLOCK_DATA: + case I2C_SMBUS_BLOCK_PROC_CALL: + for (i = 0; i <= f7_msg->smbus_buf[0]; i++) + data->block[i] = f7_msg->smbus_buf[i]; + break; + default: + dev_err(dev, "Unsupported smbus transaction\n"); + ret = -EINVAL; + } + } + +pm_free: + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + return ret; +} + +static void stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev *i2c_dev, + bool enable) +{ + void __iomem *base = i2c_dev->base; + u32 mask = STM32F7_I2C_CR1_WUPEN; + + if (!i2c_dev->wakeup_src) + return; + + if (enable) { + device_set_wakeup_enable(i2c_dev->dev, true); + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask); + } else { + device_set_wakeup_enable(i2c_dev->dev, false); + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask); + } +} + +static int stm32f7_i2c_reg_slave(struct i2c_client *slave) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter); + void __iomem *base = i2c_dev->base; + struct device *dev = i2c_dev->dev; + u32 oar1, oar2, mask; + int id, ret; + + if (slave->flags & I2C_CLIENT_PEC) { + dev_err(dev, "SMBus PEC not supported in slave mode\n"); + return -EINVAL; + } + + if (stm32f7_i2c_is_slave_busy(i2c_dev)) { + dev_err(dev, "Too much slave registered\n"); + return -EBUSY; + } + + ret = stm32f7_i2c_get_free_slave_id(i2c_dev, slave, &id); + if (ret) + return ret; + + ret = pm_runtime_resume_and_get(dev); + if (ret < 0) + return ret; + + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) + stm32f7_i2c_enable_wakeup(i2c_dev, true); + + switch (id) { + case 0: + /* Slave SMBus Host */ + i2c_dev->slave[id] = slave; + break; + + case 1: + /* Configure Own Address 1 */ + oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1); + oar1 &= ~STM32F7_I2C_OAR1_MASK; + if (slave->flags & I2C_CLIENT_TEN) { + oar1 |= STM32F7_I2C_OAR1_OA1_10(slave->addr); + oar1 |= STM32F7_I2C_OAR1_OA1MODE; + } else { + oar1 |= STM32F7_I2C_OAR1_OA1_7(slave->addr); + } + oar1 |= STM32F7_I2C_OAR1_OA1EN; + i2c_dev->slave[id] = slave; + writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1); + break; + + case 2: + /* Configure Own Address 2 */ + oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2); + oar2 &= ~STM32F7_I2C_OAR2_MASK; + if (slave->flags & I2C_CLIENT_TEN) { + ret = -EOPNOTSUPP; + goto pm_free; + } + + oar2 |= STM32F7_I2C_OAR2_OA2_7(slave->addr); + oar2 |= STM32F7_I2C_OAR2_OA2EN; + i2c_dev->slave[id] = slave; + writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2); + break; + + default: + dev_err(dev, "I2C slave id not supported\n"); + ret = -ENODEV; + goto pm_free; + } + + /* Enable ACK */ + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, STM32F7_I2C_CR2_NACK); + + /* Enable Address match interrupt, error interrupt and enable I2C */ + mask = STM32F7_I2C_CR1_ADDRIE | STM32F7_I2C_CR1_ERRIE | + STM32F7_I2C_CR1_PE; + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask); + + ret = 0; +pm_free: + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) + stm32f7_i2c_enable_wakeup(i2c_dev, false); + + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + + return ret; +} + +static int stm32f7_i2c_unreg_slave(struct i2c_client *slave) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter); + void __iomem *base = i2c_dev->base; + u32 mask; + int id, ret; + + ret = stm32f7_i2c_get_slave_id(i2c_dev, slave, &id); + if (ret) + return ret; + + WARN_ON(!i2c_dev->slave[id]); + + ret = pm_runtime_resume_and_get(i2c_dev->dev); + if (ret < 0) + return ret; + + if (id == 1) { + mask = STM32F7_I2C_OAR1_OA1EN; + stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask); + } else if (id == 2) { + mask = STM32F7_I2C_OAR2_OA2EN; + stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask); + } + + i2c_dev->slave[id] = NULL; + + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) { + stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK); + stm32f7_i2c_enable_wakeup(i2c_dev, false); + } + + pm_runtime_mark_last_busy(i2c_dev->dev); + pm_runtime_put_autosuspend(i2c_dev->dev); + + return 0; +} + +static int stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev *i2c_dev, + bool enable) +{ + int ret; + + if (i2c_dev->bus_rate <= I2C_MAX_FAST_MODE_FREQ || + IS_ERR_OR_NULL(i2c_dev->regmap)) + /* Optional */ + return 0; + + if (i2c_dev->fmp_sreg == i2c_dev->fmp_creg) + ret = regmap_update_bits(i2c_dev->regmap, + i2c_dev->fmp_sreg, + i2c_dev->fmp_mask, + enable ? i2c_dev->fmp_mask : 0); + else + ret = regmap_write(i2c_dev->regmap, + enable ? i2c_dev->fmp_sreg : + i2c_dev->fmp_creg, + i2c_dev->fmp_mask); + + return ret; +} + +static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev, + struct stm32f7_i2c_dev *i2c_dev) +{ + struct device_node *np = pdev->dev.of_node; + int ret; + + i2c_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg-fmp"); + if (IS_ERR(i2c_dev->regmap)) + /* Optional */ + return 0; + + ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1, + &i2c_dev->fmp_sreg); + if (ret) + return ret; + + i2c_dev->fmp_creg = i2c_dev->fmp_sreg + + i2c_dev->setup.fmp_clr_offset; + + return of_property_read_u32_index(np, "st,syscfg-fmp", 2, + &i2c_dev->fmp_mask); +} + +static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev) +{ + struct i2c_adapter *adap = &i2c_dev->adap; + void __iomem *base = i2c_dev->base; + struct i2c_client *client; + + client = i2c_new_slave_host_notify_device(adap); + if (IS_ERR(client)) + return PTR_ERR(client); + + i2c_dev->host_notify_client = client; + + /* Enable SMBus Host address */ + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN); + + return 0; +} + +static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev) +{ + void __iomem *base = i2c_dev->base; + + if (i2c_dev->host_notify_client) { + /* Disable SMBus Host address */ + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_SMBHEN); + i2c_free_slave_host_notify_device(i2c_dev->host_notify_client); + } +} + +static int stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_alert *alert; + struct i2c_adapter *adap = &i2c_dev->adap; + struct device *dev = i2c_dev->dev; + void __iomem *base = i2c_dev->base; + + alert = devm_kzalloc(dev, sizeof(*alert), GFP_KERNEL); + if (!alert) + return -ENOMEM; + + alert->ara = i2c_new_smbus_alert_device(adap, &alert->setup); + if (IS_ERR(alert->ara)) + return PTR_ERR(alert->ara); + + i2c_dev->alert = alert; + + /* Enable SMBus Alert */ + stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_ALERTEN); + + return 0; +} + +static void stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev) +{ + struct stm32f7_i2c_alert *alert = i2c_dev->alert; + void __iomem *base = i2c_dev->base; + + if (alert) { + /* Disable SMBus Alert */ + stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_ALERTEN); + i2c_unregister_device(alert->ara); + } +} + +static u32 stm32f7_i2c_func(struct i2c_adapter *adap) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap); + + u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE | + I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | + I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC | + I2C_FUNC_SMBUS_I2C_BLOCK; + + if (i2c_dev->smbus_mode) + func |= I2C_FUNC_SMBUS_HOST_NOTIFY; + + return func; +} + +static const struct i2c_algorithm stm32f7_i2c_algo = { + .master_xfer = stm32f7_i2c_xfer, + .smbus_xfer = stm32f7_i2c_smbus_xfer, + .functionality = stm32f7_i2c_func, + .reg_slave = stm32f7_i2c_reg_slave, + .unreg_slave = stm32f7_i2c_unreg_slave, +}; + +static int stm32f7_i2c_probe(struct platform_device *pdev) +{ + struct stm32f7_i2c_dev *i2c_dev; + const struct stm32f7_i2c_setup *setup; + struct resource *res; + struct i2c_adapter *adap; + struct reset_control *rst; + dma_addr_t phy_addr; + int irq_error, irq_event, ret; + + i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); + if (!i2c_dev) + return -ENOMEM; + + i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); + if (IS_ERR(i2c_dev->base)) + return PTR_ERR(i2c_dev->base); + phy_addr = (dma_addr_t)res->start; + + irq_event = platform_get_irq(pdev, 0); + if (irq_event < 0) + return irq_event; + + irq_error = platform_get_irq(pdev, 1); + if (irq_error < 0) + return irq_error; + + i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node, + "wakeup-source"); + + i2c_dev->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(i2c_dev->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->clk), + "Failed to get controller clock\n"); + + ret = clk_prepare_enable(i2c_dev->clk); + if (ret) { + dev_err(&pdev->dev, "Failed to prepare_enable clock\n"); + return ret; + } + + rst = devm_reset_control_get(&pdev->dev, NULL); + if (IS_ERR(rst)) { + ret = dev_err_probe(&pdev->dev, PTR_ERR(rst), + "Error: Missing reset ctrl\n"); + goto clk_free; + } + reset_control_assert(rst); + udelay(2); + reset_control_deassert(rst); + + i2c_dev->dev = &pdev->dev; + + ret = devm_request_threaded_irq(&pdev->dev, irq_event, + stm32f7_i2c_isr_event, + stm32f7_i2c_isr_event_thread, + IRQF_ONESHOT, + pdev->name, i2c_dev); + if (ret) { + dev_err(&pdev->dev, "Failed to request irq event %i\n", + irq_event); + goto clk_free; + } + + ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0, + pdev->name, i2c_dev); + if (ret) { + dev_err(&pdev->dev, "Failed to request irq error %i\n", + irq_error); + goto clk_free; + } + + setup = of_device_get_match_data(&pdev->dev); + if (!setup) { + dev_err(&pdev->dev, "Can't get device data\n"); + ret = -ENODEV; + goto clk_free; + } + i2c_dev->setup = *setup; + + ret = stm32f7_i2c_setup_timing(i2c_dev, &i2c_dev->setup); + if (ret) + goto clk_free; + + /* Setup Fast mode plus if necessary */ + if (i2c_dev->bus_rate > I2C_MAX_FAST_MODE_FREQ) { + ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev); + if (ret) + goto clk_free; + ret = stm32f7_i2c_write_fm_plus_bits(i2c_dev, true); + if (ret) + goto clk_free; + } + + adap = &i2c_dev->adap; + i2c_set_adapdata(adap, i2c_dev); + snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)", + &res->start); + adap->owner = THIS_MODULE; + adap->timeout = 2 * HZ; + adap->retries = 3; + adap->algo = &stm32f7_i2c_algo; + adap->dev.parent = &pdev->dev; + adap->dev.of_node = pdev->dev.of_node; + + init_completion(&i2c_dev->complete); + + /* Init DMA config if supported */ + i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr, + STM32F7_I2C_TXDR, + STM32F7_I2C_RXDR); + if (IS_ERR(i2c_dev->dma)) { + ret = PTR_ERR(i2c_dev->dma); + /* DMA support is optional, only report other errors */ + if (ret != -ENODEV) + goto fmp_clear; + dev_dbg(i2c_dev->dev, "No DMA option: fallback using interrupts\n"); + i2c_dev->dma = NULL; + } + + if (i2c_dev->wakeup_src) { + device_set_wakeup_capable(i2c_dev->dev, true); + + ret = dev_pm_set_wake_irq(i2c_dev->dev, irq_event); + if (ret) { + dev_err(i2c_dev->dev, "Failed to set wake up irq\n"); + goto clr_wakeup_capable; + } + } + + platform_set_drvdata(pdev, i2c_dev); + + pm_runtime_set_autosuspend_delay(i2c_dev->dev, + STM32F7_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(i2c_dev->dev); + pm_runtime_set_active(i2c_dev->dev); + pm_runtime_enable(i2c_dev->dev); + + pm_runtime_get_noresume(&pdev->dev); + + stm32f7_i2c_hw_config(i2c_dev); + + i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus"); + + ret = i2c_add_adapter(adap); + if (ret) + goto pm_disable; + + if (i2c_dev->smbus_mode) { + ret = stm32f7_i2c_enable_smbus_host(i2c_dev); + if (ret) { + dev_err(i2c_dev->dev, + "failed to enable SMBus Host-Notify protocol (%d)\n", + ret); + goto i2c_adapter_remove; + } + } + + if (of_property_read_bool(pdev->dev.of_node, "smbus-alert")) { + ret = stm32f7_i2c_enable_smbus_alert(i2c_dev); + if (ret) { + dev_err(i2c_dev->dev, + "failed to enable SMBus alert protocol (%d)\n", + ret); + goto i2c_disable_smbus_host; + } + } + + dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr); + + pm_runtime_mark_last_busy(i2c_dev->dev); + pm_runtime_put_autosuspend(i2c_dev->dev); + + return 0; + +i2c_disable_smbus_host: + stm32f7_i2c_disable_smbus_host(i2c_dev); + +i2c_adapter_remove: + i2c_del_adapter(adap); + +pm_disable: + pm_runtime_put_noidle(i2c_dev->dev); + pm_runtime_disable(i2c_dev->dev); + pm_runtime_set_suspended(i2c_dev->dev); + pm_runtime_dont_use_autosuspend(i2c_dev->dev); + + if (i2c_dev->wakeup_src) + dev_pm_clear_wake_irq(i2c_dev->dev); + +clr_wakeup_capable: + if (i2c_dev->wakeup_src) + device_set_wakeup_capable(i2c_dev->dev, false); + + if (i2c_dev->dma) { + stm32_i2c_dma_free(i2c_dev->dma); + i2c_dev->dma = NULL; + } + +fmp_clear: + stm32f7_i2c_write_fm_plus_bits(i2c_dev, false); + +clk_free: + clk_disable_unprepare(i2c_dev->clk); + + return ret; +} + +static void stm32f7_i2c_remove(struct platform_device *pdev) +{ + struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev); + + stm32f7_i2c_disable_smbus_alert(i2c_dev); + stm32f7_i2c_disable_smbus_host(i2c_dev); + + i2c_del_adapter(&i2c_dev->adap); + pm_runtime_get_sync(i2c_dev->dev); + + if (i2c_dev->wakeup_src) { + dev_pm_clear_wake_irq(i2c_dev->dev); + /* + * enforce that wakeup is disabled and that the device + * is marked as non wakeup capable + */ + device_init_wakeup(i2c_dev->dev, false); + } + + pm_runtime_put_noidle(i2c_dev->dev); + pm_runtime_disable(i2c_dev->dev); + pm_runtime_set_suspended(i2c_dev->dev); + pm_runtime_dont_use_autosuspend(i2c_dev->dev); + + if (i2c_dev->dma) { + stm32_i2c_dma_free(i2c_dev->dma); + i2c_dev->dma = NULL; + } + + stm32f7_i2c_write_fm_plus_bits(i2c_dev, false); + + clk_disable_unprepare(i2c_dev->clk); +} + +static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev) +{ + struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev); + + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) + clk_disable_unprepare(i2c_dev->clk); + + return 0; +} + +static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev) +{ + struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev); + int ret; + + if (!stm32f7_i2c_is_slave_registered(i2c_dev)) { + ret = clk_prepare_enable(i2c_dev->clk); + if (ret) { + dev_err(dev, "failed to prepare_enable clock\n"); + return ret; + } + } + + return 0; +} + +static int __maybe_unused stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev) +{ + int ret; + struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs; + + ret = pm_runtime_resume_and_get(i2c_dev->dev); + if (ret < 0) + return ret; + + backup_regs->cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1); + backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2); + backup_regs->oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1); + backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2); + backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR); + stm32f7_i2c_write_fm_plus_bits(i2c_dev, false); + + pm_runtime_put_sync(i2c_dev->dev); + + return ret; +} + +static int __maybe_unused stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev) +{ + u32 cr1; + int ret; + struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs; + + ret = pm_runtime_resume_and_get(i2c_dev->dev); + if (ret < 0) + return ret; + + cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1); + if (cr1 & STM32F7_I2C_CR1_PE) + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_PE); + + writel_relaxed(backup_regs->tmgr, i2c_dev->base + STM32F7_I2C_TIMINGR); + writel_relaxed(backup_regs->cr1 & ~STM32F7_I2C_CR1_PE, + i2c_dev->base + STM32F7_I2C_CR1); + if (backup_regs->cr1 & STM32F7_I2C_CR1_PE) + stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_PE); + writel_relaxed(backup_regs->cr2, i2c_dev->base + STM32F7_I2C_CR2); + writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1); + writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2); + stm32f7_i2c_write_fm_plus_bits(i2c_dev, true); + + pm_runtime_put_sync(i2c_dev->dev); + + return ret; +} + +static int __maybe_unused stm32f7_i2c_suspend(struct device *dev) +{ + struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev); + int ret; + + i2c_mark_adapter_suspended(&i2c_dev->adap); + + if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) { + ret = stm32f7_i2c_regs_backup(i2c_dev); + if (ret < 0) { + i2c_mark_adapter_resumed(&i2c_dev->adap); + return ret; + } + + pinctrl_pm_select_sleep_state(dev); + pm_runtime_force_suspend(dev); + } + + return 0; +} + +static int __maybe_unused stm32f7_i2c_resume(struct device *dev) +{ + struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev); + int ret; + + if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) { + ret = pm_runtime_force_resume(dev); + if (ret < 0) + return ret; + pinctrl_pm_select_default_state(dev); + + ret = stm32f7_i2c_regs_restore(i2c_dev); + if (ret < 0) + return ret; + } + + i2c_mark_adapter_resumed(&i2c_dev->adap); + + return 0; +} + +static const struct dev_pm_ops stm32f7_i2c_pm_ops = { + SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend, + stm32f7_i2c_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(stm32f7_i2c_suspend, stm32f7_i2c_resume) +}; + +static const struct of_device_id stm32f7_i2c_match[] = { + { .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup}, + { .compatible = "st,stm32mp15-i2c", .data = &stm32mp15_setup}, + { .compatible = "st,stm32mp13-i2c", .data = &stm32mp13_setup}, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32f7_i2c_match); + +static struct platform_driver stm32f7_i2c_driver = { + .driver = { + .name = "stm32f7-i2c", + .of_match_table = stm32f7_i2c_match, + .pm = &stm32f7_i2c_pm_ops, + }, + .probe = stm32f7_i2c_probe, + .remove_new = stm32f7_i2c_remove, +}; + +module_platform_driver(stm32f7_i2c_driver); + +MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>"); +MODULE_DESCRIPTION("STMicroelectronics STM32F7 I2C driver"); +MODULE_LICENSE("GPL v2"); |