This patch updates the stm32 i2c driver. The original source is taken from the STMicroelectronics/u-boot repository [1]. As a bonus from the update, the i2c_probe command now works properly, added support for stm32mp13x CPUs and a parser for some stm32-specific i2c devicetree properties.
[1] https://github.com/STMicroelectronics/u-boot/blob/v2022.10-stm32mp/drivers/i2c/stm32f7_i2c.c Signed-off-by: Alexander Shiyan <[email protected]> --- drivers/i2c/busses/i2c-stm32.c | 442 +++++++++++++++++++++------------ 1 file changed, 277 insertions(+), 165 deletions(-) diff --git a/drivers/i2c/busses/i2c-stm32.c b/drivers/i2c/busses/i2c-stm32.c index 39e345e2cc..ba0d4a51b5 100644 --- a/drivers/i2c/busses/i2c-stm32.c +++ b/drivers/i2c/busses/i2c-stm32.c @@ -9,9 +9,11 @@ #include <common.h> #include <i2c/i2c.h> #include <init.h> +#include <regmap.h> #include <linux/clk.h> #include <linux/iopoll.h> #include <linux/reset.h> +#include <mfd/syscon.h> /* STM32 I2C registers */ struct __packed stm32_i2c_regs { @@ -38,6 +40,8 @@ struct __packed stm32_i2c_regs { /* STM32 I2C control 1 */ #define STM32_I2C_CR1_ANFOFF BIT(12) +#define STM32_I2C_CR1_DNF_MASK GENMASK(11, 8) +#define STM32_I2C_CR1_DNF(n) (((n) & 0xf) << 8) #define STM32_I2C_CR1_ERRIE BIT(7) #define STM32_I2C_CR1_TCIE BIT(6) #define STM32_I2C_CR1_STOPIE BIT(5) @@ -48,7 +52,6 @@ struct __packed stm32_i2c_regs { #define STM32_I2C_CR1_PE BIT(0) /* STM32 I2C control 2 */ -#define STM32_I2C_CR2_AUTOEND BIT(25) #define STM32_I2C_CR2_RELOAD BIT(24) #define STM32_I2C_CR2_NBYTES_MASK GENMASK(23, 16) #define STM32_I2C_CR2_NBYTES(n) ((n & 0xff) << 16) @@ -98,10 +101,8 @@ struct __packed stm32_i2c_regs { #define STM32_I2C_MAX_LEN 0xff -#define STM32_I2C_DNF_DEFAULT 0 -#define STM32_I2C_DNF_MAX 16 +#define STM32_I2C_DNF_MAX 15 -#define STM32_I2C_ANALOG_FILTER_ENABLE 1 #define STM32_I2C_ANALOG_FILTER_DELAY_MIN 50 /* ns */ #define STM32_I2C_ANALOG_FILTER_DELAY_MAX 260 /* ns */ @@ -119,10 +120,9 @@ struct __packed stm32_i2c_regs { #define FAST_PLUS_RATE 1000000 enum stm32_i2c_speed { - STM32_I2C_SPEED_STANDARD, /* 100 kHz */ - STM32_I2C_SPEED_FAST, /* 400 kHz */ - STM32_I2C_SPEED_FAST_PLUS, /* 1 MHz */ - STM32_I2C_SPEED_END, + IC_SPEED_MODE_STANDARD, + IC_SPEED_MODE_FAST, + IC_SPEED_MODE_FAST_PLUS, }; /** @@ -154,20 +154,23 @@ struct stm32_i2c_spec { /** * struct stm32_i2c_setup - private I2C timing setup parameters - * @speed: I2C speed mode (standard, Fast Plus) - * @speed_freq: actual I2C speed frequency (Hz) * @clock_src: I2C clock source frequency (Hz) - * @dnf: Digital filter coefficient (0-16) + * @timings: I2C timing information * @analog_filter: Analog filter delay (On/Off) - * @timings: I2C timings parameters */ struct stm32_i2c_setup { - enum stm32_i2c_speed speed; - u32 speed_freq; u32 clock_src; + struct i2c_timings timings; u8 dnf; bool analog_filter; - struct i2c_timings timings; +}; + +/** + * struct stm32_i2c_data - driver data for I2C configuration by compatible + * @fmp_clr_offset: Fast Mode Plus clear register offset from set register + */ +struct stm32_i2c_data { + u32 fmp_clr_offset; }; /** @@ -187,8 +190,32 @@ struct stm32_i2c_timings { u8 scll; }; +/** + * struct stm32_i2c_priv - private data of the controller + * @regs: I2C registers address + * @clk: hw i2c clock + * @setup: I2C timing setup parameters + * @speed: I2C clock frequency of the controller. Standard, Fast or Fast+ + * @regmap: holds SYSCFG phandle for Fast Mode Plus bit + * @regmap_sreg: register address for setting Fast Mode Plus bits + * @regmap_creg: register address for clearing Fast Mode Plus bits + * @regmap_mask: mask for Fast Mode Plus bits + */ +struct stm32_i2c_priv { + struct stm32_i2c_regs __iomem *regs; + struct clk *clk; + struct i2c_adapter adapter; + struct stm32_i2c_setup setup; + u32 speed; + struct regmap *regmap; + u32 regmap_sreg; + u32 regmap_creg; + u32 regmap_mask; +}; + static const struct stm32_i2c_spec i2c_specs[] = { - [STM32_I2C_SPEED_STANDARD] = { + /* Standard speed - 100 KHz */ + [IC_SPEED_MODE_STANDARD] = { .rate = STANDARD_RATE, .rate_min = 8000, .rate_max = 120000, @@ -200,7 +227,8 @@ static const struct stm32_i2c_spec i2c_specs[] = { .l_min = 4700, .h_min = 4000, }, - [STM32_I2C_SPEED_FAST] = { + /* Fast speed - 400 KHz */ + [IC_SPEED_MODE_FAST] = { .rate = FAST_RATE, .rate_min = 320000, .rate_max = 480000, @@ -212,7 +240,8 @@ static const struct stm32_i2c_spec i2c_specs[] = { .l_min = 1300, .h_min = 600, }, - [STM32_I2C_SPEED_FAST_PLUS] = { + /* Fast Plus Speed - 1 MHz */ + [IC_SPEED_MODE_FAST_PLUS] = { .rate = FAST_PLUS_RATE, .rate_min = 800000, .rate_max = 1200000, @@ -226,22 +255,30 @@ static const struct stm32_i2c_spec i2c_specs[] = { }, }; -struct stm32_i2c { - struct stm32_i2c_regs __iomem *regs; - struct clk *clk; - struct i2c_adapter adapter; - struct stm32_i2c_setup setup; +static const struct stm32_i2c_data stm32f7_data = { + .fmp_clr_offset = 0x00, +}; + +static const struct stm32_i2c_data stm32mp15_data = { + .fmp_clr_offset = 0x40, +}; + +static const struct stm32_i2c_data stm32mp13_data = { + .fmp_clr_offset = 0x4, }; -#define to_stm32_i2c(a) container_of(a, struct stm32_i2c, adapter) -static inline int stm32_i2c_check_device_busy(struct stm32_i2c *priv) +static inline int stm32_i2c_check_device_busy(struct stm32_i2c_priv *priv) { u32 status = readl(&priv->regs->isr); - return status & STM32_I2C_ISR_BUSY; + + if (status & STM32_I2C_ISR_BUSY) + return -EBUSY; + + return 0; } -static void stm32_i2c_message_start(struct stm32_i2c *i2c_priv, - struct i2c_msg *msg, bool stop) +static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv, + struct i2c_msg *msg) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 cr2 = readl(®s->cr2); @@ -262,9 +299,8 @@ static void stm32_i2c_message_start(struct stm32_i2c *i2c_priv, cr2 |= STM32_I2C_CR2_SADD7(msg->addr); } - /* Set nb bytes to transfer and reload or autoend bits */ - cr2 &= ~(STM32_I2C_CR2_NBYTES_MASK | STM32_I2C_CR2_RELOAD | - STM32_I2C_CR2_AUTOEND); + /* Set nb bytes to transfer and reload (if needed) */ + cr2 &= ~(STM32_I2C_CR2_NBYTES_MASK | STM32_I2C_CR2_RELOAD); if (msg->len > STM32_I2C_MAX_LEN) { cr2 |= STM32_I2C_CR2_NBYTES(STM32_I2C_MAX_LEN); cr2 |= STM32_I2C_CR2_RELOAD; @@ -284,8 +320,8 @@ static void stm32_i2c_message_start(struct stm32_i2c *i2c_priv, * sent is greater than MAX_LEN */ -static void stm32_i2c_handle_reload(struct stm32_i2c *i2c_priv, - struct i2c_msg *msg, bool stop) +static void stm32_i2c_handle_reload(struct stm32_i2c_priv *i2c_priv, + struct i2c_msg *msg) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 cr2 = readl(®s->cr2); @@ -302,7 +338,7 @@ static void stm32_i2c_handle_reload(struct stm32_i2c *i2c_priv, writel(cr2, ®s->cr2); } -static int stm32_i2c_wait_flags(struct stm32_i2c *i2c_priv, +static int stm32_i2c_wait_flags(struct stm32_i2c_priv *i2c_priv, u32 flags, u32 *status) { struct stm32_i2c_regs *regs = i2c_priv->regs; @@ -311,7 +347,7 @@ static int stm32_i2c_wait_flags(struct stm32_i2c *i2c_priv, *status & flags, USEC_PER_SEC); } -static int stm32_i2c_check_end_of_message(struct stm32_i2c *i2c_priv) +static int stm32_i2c_check_end_of_message(struct stm32_i2c_priv *i2c_priv) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 mask = STM32_I2C_ISR_ERRORS | STM32_I2C_ISR_NACKF | @@ -362,30 +398,29 @@ static int stm32_i2c_check_end_of_message(struct stm32_i2c *i2c_priv) setbits_le32(®s->icr, STM32_I2C_ICR_STOPCF); /* Clear control register 2 */ - setbits_le32(®s->cr2, STM32_I2C_CR2_RESET_MASK); + clrbits_le32(®s->cr2, STM32_I2C_CR2_RESET_MASK); } return ret; } -static int stm32_i2c_message_xfer(struct stm32_i2c *i2c_priv, +static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv, struct i2c_msg *msg, bool stop) { struct stm32_i2c_regs *regs = i2c_priv->regs; - int len = msg->len; - u8 *buf = msg->buf; u32 status; u32 mask = msg->flags & I2C_M_RD ? STM32_I2C_ISR_RXNE : STM32_I2C_ISR_TXIS | STM32_I2C_ISR_NACKF; - int bytes_to_rw = min(len, STM32_I2C_MAX_LEN); + int bytes_to_rw = msg->len > STM32_I2C_MAX_LEN ? + STM32_I2C_MAX_LEN : msg->len; int ret = 0; /* Add errors */ mask |= STM32_I2C_ISR_ERRORS; - stm32_i2c_message_start(i2c_priv, msg, stop); + stm32_i2c_message_start(i2c_priv, msg); - while (len) { + while (msg->len) { /* * Wait until TXIS/NACKF/BERR/ARLO flags or * RXNE/BERR/ARLO flags are set @@ -398,29 +433,30 @@ static int stm32_i2c_message_xfer(struct stm32_i2c *i2c_priv, break; if (status & STM32_I2C_ISR_RXNE) { - *buf++ = readb(®s->rxdr); - len--; + *msg->buf++ = readb(®s->rxdr); + msg->len--; bytes_to_rw--; } if (status & STM32_I2C_ISR_TXIS) { - writeb(*buf++, ®s->txdr); - len--; + writeb(*msg->buf++, ®s->txdr); + msg->len--; bytes_to_rw--; } - if (!bytes_to_rw && len) { + if (!bytes_to_rw && msg->len) { /* Wait until TCR flag is set */ mask = STM32_I2C_ISR_TCR; ret = stm32_i2c_wait_flags(i2c_priv, mask, &status); if (ret) break; - bytes_to_rw = min(len, STM32_I2C_MAX_LEN); + bytes_to_rw = msg->len > STM32_I2C_MAX_LEN ? + STM32_I2C_MAX_LEN : msg->len; mask = msg->flags & I2C_M_RD ? STM32_I2C_ISR_RXNE : STM32_I2C_ISR_TXIS | STM32_I2C_ISR_NACKF; - stm32_i2c_handle_reload(i2c_priv, msg, stop); + stm32_i2c_handle_reload(i2c_priv, msg); } else if (!bytes_to_rw) { /* Wait until TC flag is set */ mask = STM32_I2C_ISR_TC; @@ -434,9 +470,9 @@ static int stm32_i2c_message_xfer(struct stm32_i2c *i2c_priv, } } - /* End of transfer, send stop condition */ - mask = STM32_I2C_CR2_STOP; - setbits_le32(®s->cr2, mask); + /* End of transfer, send stop condition if appropriate */ + if (!ret && !(status & (STM32_I2C_ISR_NACKF | STM32_I2C_ISR_ERRORS))) + setbits_le32(®s->cr2, STM32_I2C_CR2_STOP); return stm32_i2c_check_end_of_message(i2c_priv); } @@ -444,16 +480,16 @@ static int stm32_i2c_message_xfer(struct stm32_i2c *i2c_priv, static int stm32_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msg, int nmsgs) { - struct stm32_i2c *i2c_priv = to_stm32_i2c(adapter); - int ret; - int i; + struct stm32_i2c_priv *i2c_priv = + container_of(adapter, struct stm32_i2c_priv, adapter); + int i, ret; ret = stm32_i2c_check_device_busy(i2c_priv); if (ret) - return -EBUSY; + return ret; - for (i = 0; i < nmsgs; i++) { - ret = stm32_i2c_message_xfer(i2c_priv, &msg[i], i == nmsgs - 1); + for (i = nmsgs; i > 0; i--, msg++) { + ret = stm32_i2c_message_xfer(i2c_priv, msg, i == 1); if (ret) return ret; } @@ -461,30 +497,30 @@ static int stm32_i2c_xfer(struct i2c_adapter *adapter, return nmsgs; } - -static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, +static int stm32_i2c_compute_solutions(u32 i2cclk, + struct stm32_i2c_setup *setup, + const struct stm32_i2c_spec *specs, struct list_head *solutions) { struct stm32_i2c_timings *v; u32 p_prev = STM32_PRESC_MAX; - u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC, setup->clock_src); - u32 af_delay_min = 0, af_delay_max = 0; + u32 af_delay_min, af_delay_max; u16 p, l, a; int sdadel_min, sdadel_max, scldel_min; int ret = 0; - if (setup->analog_filter) { - af_delay_min = STM32_I2C_ANALOG_FILTER_DELAY_MIN; - af_delay_max = STM32_I2C_ANALOG_FILTER_DELAY_MAX; - } + af_delay_min = setup->analog_filter ? + STM32_I2C_ANALOG_FILTER_DELAY_MIN : 0; + af_delay_max = setup->analog_filter ? + STM32_I2C_ANALOG_FILTER_DELAY_MAX : 0; - sdadel_min = i2c_specs[setup->speed].hddat_min + setup->timings.scl_fall_ns - + sdadel_min = specs->hddat_min + setup->timings.scl_fall_ns - af_delay_min - (setup->dnf + 3) * i2cclk; - sdadel_max = i2c_specs[setup->speed].vddat_max - setup->timings.scl_rise_ns - + sdadel_max = specs->vddat_max - setup->timings.scl_rise_ns - af_delay_max - (setup->dnf + 4) * i2cclk; - scldel_min = setup->timings.scl_rise_ns + i2c_specs[setup->speed].sudat_min; + scldel_min = setup->timings.scl_rise_ns + specs->sudat_min; if (sdadel_min < 0) sdadel_min = 0; @@ -497,13 +533,13 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, /* Compute possible values for PRESC, SCLDEL and SDADEL */ for (p = 0; p < STM32_PRESC_MAX; p++) { for (l = 0; l < STM32_SCLDEL_MAX; l++) { - u32 scldel = (l + 1) * (p + 1) * i2cclk; + int scldel = (l + 1) * (p + 1) * i2cclk; if (scldel < scldel_min) continue; for (a = 0; a < STM32_SDADEL_MAX; a++) { - u32 sdadel = (a * (p + 1) + 1) * i2cclk; + int sdadel = (a * (p + 1) + 1) * i2cclk; if (((sdadel >= sdadel_min) && (sdadel <= sdadel_max)) && @@ -527,36 +563,40 @@ static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, } } - if (list_empty(solutions)) + if (list_empty(solutions)) { + pr_err("no Prescaler solution\n"); ret = -EPERM; + } return ret; } -static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, +static int stm32_i2c_choose_solution(u32 i2cclk, + struct stm32_i2c_setup *setup, + const struct stm32_i2c_spec *specs, struct list_head *solutions, struct stm32_i2c_timings *s) { struct stm32_i2c_timings *v; - u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC, setup->speed_freq); + u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC, + setup->timings.bus_freq_hz); u32 clk_error_prev = i2cbus; - u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC, setup->clock_src); u32 clk_min, clk_max; - u32 af_delay_min = 0; + u32 af_delay_min; u32 dnf_delay; u32 tsync; u16 l, h; bool sol_found = false; int ret = 0; - if (setup->analog_filter) - af_delay_min = STM32_I2C_ANALOG_FILTER_DELAY_MIN; + af_delay_min = setup->analog_filter ? + STM32_I2C_ANALOG_FILTER_DELAY_MIN : 0; dnf_delay = setup->dnf * i2cclk; tsync = af_delay_min + dnf_delay + (2 * i2cclk); - clk_max = NSEC_PER_SEC / i2c_specs[setup->speed].rate_min; - clk_min = NSEC_PER_SEC / i2c_specs[setup->speed].rate_max; + clk_max = NSEC_PER_SEC / specs->rate_min; + clk_min = NSEC_PER_SEC / specs->rate_max; /* * Among Prescaler possibilities discovered above figures out SCL Low @@ -574,7 +614,7 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, for (l = 0; l < STM32_SCLL_MAX; l++) { u32 tscl_l = (l + 1) * prescaler + tsync; - if ((tscl_l < i2c_specs[setup->speed].l_min) || + if (tscl_l < specs->l_min || (i2cclk >= ((tscl_l - af_delay_min - dnf_delay) / 4))) { continue; @@ -583,16 +623,17 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, for (h = 0; h < STM32_SCLH_MAX; h++) { u32 tscl_h = (h + 1) * prescaler + tsync; u32 tscl = tscl_l + tscl_h + - setup->timings.scl_rise_ns + - setup->timings.scl_fall_ns; + setup->timings.scl_rise_ns + setup->timings.scl_fall_ns; if ((tscl >= clk_min) && (tscl <= clk_max) && - (tscl_h >= i2c_specs[setup->speed].h_min) && + (tscl_h >= specs->h_min) && (i2cclk < tscl_h)) { - int clk_error = tscl - i2cbus; + u32 clk_error; - if (clk_error < 0) - clk_error = -clk_error; + if (tscl > i2cbus) + clk_error = tscl - i2cbus; + else + clk_error = i2cbus - tscl; if (clk_error < clk_error_prev) { clk_error_prev = clk_error; @@ -606,61 +647,68 @@ static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, } } - if (!sol_found) + if (!sol_found) { + pr_err("no solution at all\n"); ret = -EPERM; + } return ret; } -static int stm32_i2c_compute_timing(struct stm32_i2c *i2c_priv, - struct stm32_i2c_setup *setup, +static const struct stm32_i2c_spec *get_specs(u32 rate) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(i2c_specs); i++) + if (rate <= i2c_specs[i].rate) + return &i2c_specs[i]; + + /* NOT REACHED */ + return ERR_PTR(-EINVAL); +} + +static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv, struct stm32_i2c_timings *output) { struct device *dev = &i2c_priv->adapter.dev; + struct stm32_i2c_setup *setup = &i2c_priv->setup; + const struct stm32_i2c_spec *specs; struct stm32_i2c_timings *v, *_v; struct list_head solutions; + u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC, setup->clock_src); int ret; - if (setup->speed >= STM32_I2C_SPEED_END) { - dev_err(dev, "speed out of bound {%d/%d}\n", - setup->speed, STM32_I2C_SPEED_END - 1); + specs = get_specs(setup->timings.bus_freq_hz); + if (specs == ERR_PTR(-EINVAL)) { + dev_err(dev, "speed out of bound {%d}\n", + setup->timings.bus_freq_hz); return -EINVAL; } - if ((setup->timings.scl_rise_ns > i2c_specs[setup->speed].rise_max) || - (setup->timings.scl_fall_ns > i2c_specs[setup->speed].fall_max)) { + if (setup->timings.scl_rise_ns > specs->rise_max || + setup->timings.scl_fall_ns > specs->fall_max) { dev_err(dev, "timings out of bound Rise{%d>%d}/Fall{%d>%d}\n", - setup->timings.scl_rise_ns, i2c_specs[setup->speed].rise_max, - setup->timings.scl_fall_ns, i2c_specs[setup->speed].fall_max); + setup->timings.scl_rise_ns, specs->rise_max, + setup->timings.scl_fall_ns, specs->fall_max); return -EINVAL; } + /* Analog and Digital Filters */ + setup->dnf = DIV_ROUND_CLOSEST(i2c_priv->setup.timings.digital_filter_width_ns, i2cclk); if (setup->dnf > STM32_I2C_DNF_MAX) { dev_err(dev, "DNF out of bound %d/%d\n", - setup->dnf, STM32_I2C_DNF_MAX); - return -EINVAL; - } - - if (setup->speed_freq > i2c_specs[setup->speed].rate) { - dev_err(dev, "Freq {%d/%d}\n", - setup->speed_freq, i2c_specs[setup->speed].rate); + setup->dnf, STM32_I2C_DNF_MAX); return -EINVAL; } INIT_LIST_HEAD(&solutions); - ret = stm32_i2c_compute_solutions(setup, &solutions); - if (ret) { - if (ret == -EPERM) - dev_err(dev, "No prescaler solution\n"); + ret = stm32_i2c_compute_solutions(i2cclk, setup, specs, &solutions); + if (ret) goto exit; - } - ret = stm32_i2c_choose_solution(setup, &solutions, output); - if (ret) { - if (ret == -EPERM) - dev_err(dev, "no solution at all\n"); + ret = stm32_i2c_choose_solution(i2cclk, setup, specs, &solutions, output); + if (ret) goto exit; - } dev_dbg(dev, "Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n", output->presc, @@ -677,16 +725,25 @@ static int stm32_i2c_compute_timing(struct stm32_i2c *i2c_priv, return ret; } -static int stm32_i2c_setup_timing(struct stm32_i2c *i2c_priv, - enum stm32_i2c_speed speed, +static u32 get_lower_rate(u32 rate) +{ + int i; + + for (i = ARRAY_SIZE(i2c_specs) - 1; i >= 0; i--) + if (rate > i2c_specs[i].rate) + return i2c_specs[i].rate; + + return i2c_specs[0].rate; +} + +static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv, struct stm32_i2c_timings *timing) { struct device *dev = &i2c_priv->adapter.dev; struct stm32_i2c_setup *setup = &i2c_priv->setup; int ret = 0; - setup->speed = speed; - setup->speed_freq = i2c_specs[setup->speed].rate; + setup->timings.bus_freq_hz = i2c_priv->speed; setup->clock_src = clk_get_rate(i2c_priv->clk); if (!setup->clock_src) { @@ -695,15 +752,14 @@ static int stm32_i2c_setup_timing(struct stm32_i2c *i2c_priv, } do { - ret = stm32_i2c_compute_timing(i2c_priv, setup, timing); + ret = stm32_i2c_compute_timing(i2c_priv, timing); if (ret) { dev_dbg(dev, "failed to compute I2C timings.\n"); - if (speed > STM32_I2C_SPEED_STANDARD) { - speed--; - setup->speed = speed; - setup->speed_freq = i2c_specs[setup->speed].rate; + if (setup->timings.bus_freq_hz > STANDARD_RATE) { + setup->timings.bus_freq_hz = + get_lower_rate(setup->timings.bus_freq_hz); dev_dbg(dev, "downgrade I2C Speed Freq to (%i)\n", - i2c_specs[setup->speed].rate); + setup->timings.bus_freq_hz); } else { break; } @@ -715,31 +771,60 @@ static int stm32_i2c_setup_timing(struct stm32_i2c *i2c_priv, return ret; } - dev_dbg(dev, "I2C Speed(%i), Freq(%i), Clk Source(%i)\n", - setup->speed, setup->speed_freq, setup->clock_src); + dev_dbg(dev, "I2C Freq(%i), Clk Source(%i)\n", + setup->timings.bus_freq_hz, setup->clock_src); dev_dbg(dev, "I2C Rise(%i) and Fall(%i) Time\n", - setup->timings.scl_rise_ns, setup->timings.scl_fall_ns); + setup->timings.scl_rise_ns, setup->timings.scl_fall_ns); dev_dbg(dev, "I2C Analog Filter(%s), DNF(%i)\n", - setup->analog_filter ? "On" : "Off", setup->dnf); + setup->analog_filter ? "On" : "Off", setup->dnf); + + i2c_priv->speed = setup->timings.bus_freq_hz; return 0; } -static int stm32_i2c_hw_config(struct stm32_i2c *i2c_priv, - enum stm32_i2c_speed speed) +static int stm32_i2c_write_fm_plus_bits(struct stm32_i2c_priv *i2c_priv) +{ + int ret; + bool enable = i2c_priv->speed > FAST_RATE; + + /* Optional */ + if (IS_ERR_OR_NULL(i2c_priv->regmap)) + return 0; + + if (i2c_priv->regmap_sreg == i2c_priv->regmap_creg) + ret = regmap_update_bits(i2c_priv->regmap, + i2c_priv->regmap_sreg, + i2c_priv->regmap_mask, + enable ? i2c_priv->regmap_mask : 0); + else + ret = regmap_write(i2c_priv->regmap, + enable ? i2c_priv->regmap_sreg : + i2c_priv->regmap_creg, + i2c_priv->regmap_mask); + + return ret; +} + +static int stm32_i2c_hw_config(struct stm32_i2c_priv *i2c_priv) { struct stm32_i2c_regs *regs = i2c_priv->regs; struct stm32_i2c_timings t; int ret; u32 timing = 0; - ret = stm32_i2c_setup_timing(i2c_priv, speed, &t); + ret = stm32_i2c_setup_timing(i2c_priv, &t); if (ret) return ret; /* Disable I2C */ clrbits_le32(®s->cr1, STM32_I2C_CR1_PE); + /* Setup Fast mode plus if necessary */ + ret = stm32_i2c_write_fm_plus_bits(i2c_priv); + if (ret) + return ret; + /* Timing settings */ timing |= STM32_I2C_TIMINGR_PRESC(t.presc); timing |= STM32_I2C_TIMINGR_SCLDEL(t.scldel); @@ -753,44 +838,74 @@ static int stm32_i2c_hw_config(struct stm32_i2c *i2c_priv, clrbits_le32(®s->cr1, STM32_I2C_CR1_ANFOFF); else setbits_le32(®s->cr1, STM32_I2C_CR1_ANFOFF); + + /* Program the Digital Filter */ + clrsetbits_le32(®s->cr1, STM32_I2C_CR1_DNF_MASK, + STM32_I2C_CR1_DNF(i2c_priv->setup.dnf)); + setbits_le32(®s->cr1, STM32_I2C_CR1_PE); return 0; } -static int stm32_i2c_set_bus_speed(struct stm32_i2c *i2c_priv, unsigned speed) +static int stm32_i2c_set_bus_speed(struct stm32_i2c_priv *i2c_priv, unsigned int speed) { - struct device *parent_dev = i2c_priv->adapter.dev.parent; - enum stm32_i2c_speed stm32_speed; - switch (speed) { - case STANDARD_RATE: - stm32_speed = STM32_I2C_SPEED_STANDARD; - break; - case FAST_RATE: - stm32_speed = STM32_I2C_SPEED_FAST; - break; - case FAST_PLUS_RATE: - stm32_speed = STM32_I2C_SPEED_FAST_PLUS; - break; - default: - dev_warn(parent_dev, "Speed %d not supported\n", speed); + struct device *dev = &i2c_priv->adapter.dev; + + if (speed > FAST_PLUS_RATE) { + dev_dbg(dev, "Speed %d not supported\n", speed); return -EINVAL; } - return stm32_i2c_hw_config(i2c_priv, stm32_speed); + i2c_priv->speed = speed; + + return stm32_i2c_hw_config(i2c_priv); +} + +static int stm32_of_to_plat(struct device *dev, struct stm32_i2c_priv *i2c_priv) +{ + const struct stm32_i2c_data *data; + int ret; + + ret = dev_get_drvdata(dev, (const void **)&data); + if (ret) + return ret; + + if (of_property_read_u32(dev->of_node, "i2c-digital-filter-width-ns", + &i2c_priv->setup.timings.digital_filter_width_ns)) + i2c_priv->setup.timings.digital_filter_width_ns = 0; + if (!of_property_read_bool(dev->of_node, "i2c-digital-filter")) + i2c_priv->setup.timings.digital_filter_width_ns = 0; + + i2c_priv->setup.analog_filter = + of_property_read_bool(dev->of_node, "i2c-analog-filter"); + + /* Optional */ + i2c_priv->regmap = syscon_regmap_lookup_by_phandle(dev->of_node, + "st,syscfg-fmp"); + if (!IS_ERR(i2c_priv->regmap)) { + u32 fmp[3]; + + ret = of_property_read_u32_array(dev->of_node, "st,syscfg-fmp", fmp, 3); + if (ret) + return ret; + + i2c_priv->regmap_sreg = fmp[1]; + i2c_priv->regmap_creg = fmp[1] + data->fmp_clr_offset; + i2c_priv->regmap_mask = fmp[2]; + } + + return 0; } static int __init stm32_i2c_probe(struct device *dev) { struct resource *iores; - struct stm32_i2c *stm32_i2c; + struct stm32_i2c_priv *stm32_i2c; struct i2c_platform_data *pdata; - const struct stm32_i2c_setup *setup; struct i2c_timings *timings; int ret; - pdata = dev->platform_data; - stm32_i2c = xzalloc(sizeof(*stm32_i2c)); stm32_i2c->clk = clk_get(dev, NULL); @@ -798,15 +913,20 @@ static int __init stm32_i2c_probe(struct device *dev) return PTR_ERR(stm32_i2c->clk); clk_enable(stm32_i2c->clk); + iores = dev_request_mem_resource(dev, 0); + if (IS_ERR(iores)) + return PTR_ERR(iores); + + stm32_i2c->regs = IOMEM(iores->start); + ret = device_reset_us(dev, 2); if (ret) return ret; - ret = dev_get_drvdata(dev, (const void **)&setup); + ret = stm32_of_to_plat(dev, stm32_i2c); if (ret) return ret; - stm32_i2c->setup = *setup; timings = &stm32_i2c->setup.timings; /* We've our own defaults, so don't use the i2c_parse_fw_timings ones */ @@ -824,12 +944,8 @@ static int __init stm32_i2c_probe(struct device *dev) stm32_i2c->adapter.nr = dev->id; stm32_i2c->adapter.dev.parent = dev; stm32_i2c->adapter.dev.of_node = dev->of_node; - iores = dev_request_mem_resource(dev, 0); - if (IS_ERR(iores)) - return PTR_ERR(iores); - - stm32_i2c->regs = IOMEM(iores->start); + pdata = dev->platform_data; if (pdata && pdata->bitrate) timings->bus_freq_hz = pdata->bitrate; @@ -840,14 +956,10 @@ static int __init stm32_i2c_probe(struct device *dev) return i2c_add_numbered_adapter(&stm32_i2c->adapter); } -static const struct stm32_i2c_setup stm32f7_setup = { - .dnf = STM32_I2C_DNF_DEFAULT, - .analog_filter = STM32_I2C_ANALOG_FILTER_ENABLE, -}; - static __maybe_unused struct of_device_id stm32_i2c_dt_ids[] = { - { .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup, }, - { .compatible = "st,stm32mp15-i2c", .data = &stm32f7_setup}, + { .compatible = "st,stm32f7-i2c", .data = &stm32f7_data }, + { .compatible = "st,stm32mp15-i2c", .data = &stm32mp15_data }, + { .compatible = "st,stm32mp13-i2c", .data = &stm32mp13_data }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, stm32_i2c_dt_ids); -- 2.39.1
