// SPDX-License-Identifier: GPL-2.0 /* * Copyright 2017 STMicroelectronics * Copyright 2019 Ahmad Fatoum, Pengutronix */ #define pr_fmt(fmt) "i2c-stm32: " fmt #include #include #include #include #include #include /* STM32 I2C registers */ struct __packed stm32_i2c_regs { u32 cr1; /* I2C control register 1 */ u32 cr2; /* I2C control register 2 */ u32 oar1; /* I2C own address 1 register */ u32 oar2; /* I2C own address 2 register */ u32 timingr; /* I2C timing register */ u32 timeoutr; /* I2C timeout register */ u32 isr; /* I2C interrupt and status register */ u32 icr; /* I2C interrupt clear register */ u32 pecr; /* I2C packet error checking register */ u32 rxdr; /* I2C receive data register */ u32 txdr; /* I2C transmit data register */ }; #define STM32_I2C_CR1 0x00 #define STM32_I2C_CR2 0x04 #define STM32_I2C_TIMINGR 0x10 #define STM32_I2C_ISR 0x18 #define STM32_I2C_ICR 0x1C #define STM32_I2C_RXDR 0x24 #define STM32_I2C_TXDR 0x28 /* STM32 I2C control 1 */ #define STM32_I2C_CR1_ANFOFF BIT(12) #define STM32_I2C_CR1_ERRIE BIT(7) #define STM32_I2C_CR1_TCIE BIT(6) #define STM32_I2C_CR1_STOPIE BIT(5) #define STM32_I2C_CR1_NACKIE BIT(4) #define STM32_I2C_CR1_ADDRIE BIT(3) #define STM32_I2C_CR1_RXIE BIT(2) #define STM32_I2C_CR1_TXIE BIT(1) #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) #define STM32_I2C_CR2_NACK BIT(15) #define STM32_I2C_CR2_STOP BIT(14) #define STM32_I2C_CR2_START BIT(13) #define STM32_I2C_CR2_HEAD10R BIT(12) #define STM32_I2C_CR2_ADD10 BIT(11) #define STM32_I2C_CR2_RD_WRN BIT(10) #define STM32_I2C_CR2_SADD10_MASK GENMASK(9, 0) #define STM32_I2C_CR2_SADD10(n) (n & STM32_I2C_CR2_SADD10_MASK) #define STM32_I2C_CR2_SADD7_MASK GENMASK(7, 1) #define STM32_I2C_CR2_SADD7(n) ((n & 0x7f) << 1) #define STM32_I2C_CR2_RESET_MASK (STM32_I2C_CR2_HEAD10R \ | STM32_I2C_CR2_NBYTES_MASK \ | STM32_I2C_CR2_SADD7_MASK \ | STM32_I2C_CR2_RELOAD \ | STM32_I2C_CR2_RD_WRN) /* STM32 I2C Interrupt Status */ #define STM32_I2C_ISR_BUSY BIT(15) #define STM32_I2C_ISR_ARLO BIT(9) #define STM32_I2C_ISR_BERR BIT(8) #define STM32_I2C_ISR_TCR BIT(7) #define STM32_I2C_ISR_TC BIT(6) #define STM32_I2C_ISR_STOPF BIT(5) #define STM32_I2C_ISR_NACKF BIT(4) #define STM32_I2C_ISR_ADDR BIT(3) #define STM32_I2C_ISR_RXNE BIT(2) #define STM32_I2C_ISR_TXIS BIT(1) #define STM32_I2C_ISR_TXE BIT(0) #define STM32_I2C_ISR_ERRORS (STM32_I2C_ISR_BERR \ | STM32_I2C_ISR_ARLO) /* STM32 I2C Interrupt Clear */ #define STM32_I2C_ICR_ARLOCF BIT(9) #define STM32_I2C_ICR_BERRCF BIT(8) #define STM32_I2C_ICR_STOPCF BIT(5) #define STM32_I2C_ICR_NACKCF BIT(4) /* STM32 I2C Timing */ #define STM32_I2C_TIMINGR_PRESC(n) ((n & 0xf) << 28) #define STM32_I2C_TIMINGR_SCLDEL(n) ((n & 0xf) << 20) #define STM32_I2C_TIMINGR_SDADEL(n) ((n & 0xf) << 16) #define STM32_I2C_TIMINGR_SCLH(n) ((n & 0xff) << 8) #define STM32_I2C_TIMINGR_SCLL(n) (n & 0xff) #define STM32_I2C_MAX_LEN 0xff #define STM32_I2C_DNF_DEFAULT 0 #define STM32_I2C_DNF_MAX 16 #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 */ #define STM32_I2C_RISE_TIME_DEFAULT 25 /* ns */ #define STM32_I2C_FALL_TIME_DEFAULT 10 /* ns */ #define STM32_PRESC_MAX BIT(4) #define STM32_SCLDEL_MAX BIT(4) #define STM32_SDADEL_MAX BIT(4) #define STM32_SCLH_MAX BIT(8) #define STM32_SCLL_MAX BIT(8) #define STANDARD_RATE 100000 #define FAST_RATE 400000 #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, }; /** * struct stm32_i2c_spec - private i2c specification timing * @rate: I2C bus speed (Hz) * @rate_min: 80% of I2C bus speed (Hz) * @rate_max: 120% of 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 stm32_i2c_spec { u32 rate; u32 rate_min; u32 rate_max; u32 fall_max; u32 rise_max; u32 hddat_min; u32 vddat_max; u32 sudat_min; u32 l_min; u32 h_min; }; /** * 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) * @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; u8 dnf; bool analog_filter; struct i2c_timings timings; }; /** * struct stm32_i2c_timings - private I2C output parameters * @prec: Prescaler value * @scldel: Data setup time * @sdadel: Data hold time * @sclh: SCL high period (master mode) * @sclh: SCL low period (master mode) */ struct stm32_i2c_timings { struct list_head node; u8 presc; u8 scldel; u8 sdadel; u8 sclh; u8 scll; }; static const struct stm32_i2c_spec i2c_specs[] = { [STM32_I2C_SPEED_STANDARD] = { .rate = STANDARD_RATE, .rate_min = 8000, .rate_max = 120000, .fall_max = 300, .rise_max = 1000, .hddat_min = 0, .vddat_max = 3450, .sudat_min = 250, .l_min = 4700, .h_min = 4000, }, [STM32_I2C_SPEED_FAST] = { .rate = FAST_RATE, .rate_min = 320000, .rate_max = 480000, .fall_max = 300, .rise_max = 300, .hddat_min = 0, .vddat_max = 900, .sudat_min = 100, .l_min = 1300, .h_min = 600, }, [STM32_I2C_SPEED_FAST_PLUS] = { .rate = FAST_PLUS_RATE, .rate_min = 800000, .rate_max = 1200000, .fall_max = 100, .rise_max = 120, .hddat_min = 0, .vddat_max = 450, .sudat_min = 50, .l_min = 500, .h_min = 260, }, }; struct stm32_i2c { struct stm32_i2c_regs __iomem *regs; struct clk *clk; struct i2c_adapter adapter; struct stm32_i2c_setup setup; }; #define to_stm32_i2c(a) container_of(a, struct stm32_i2c, adapter) static inline int stm32_i2c_check_device_busy(struct stm32_i2c *priv) { u32 status = readl(&priv->regs->isr); return status & STM32_I2C_ISR_BUSY; } static void stm32_i2c_message_start(struct stm32_i2c *i2c_priv, struct i2c_msg *msg, bool stop) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 cr2 = readl(®s->cr2); /* Set transfer direction */ cr2 &= ~STM32_I2C_CR2_RD_WRN; if (msg->flags & I2C_M_RD) cr2 |= STM32_I2C_CR2_RD_WRN; /* Set slave address */ cr2 &= ~(STM32_I2C_CR2_HEAD10R | STM32_I2C_CR2_ADD10); if (msg->flags & I2C_M_TEN) { cr2 &= ~STM32_I2C_CR2_SADD10_MASK; cr2 |= STM32_I2C_CR2_SADD10(msg->addr); cr2 |= STM32_I2C_CR2_ADD10; } else { cr2 &= ~STM32_I2C_CR2_SADD7_MASK; 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); if (msg->len > STM32_I2C_MAX_LEN) { cr2 |= STM32_I2C_CR2_NBYTES(STM32_I2C_MAX_LEN); cr2 |= STM32_I2C_CR2_RELOAD; } else { cr2 |= STM32_I2C_CR2_NBYTES(msg->len); } /* Write configurations register */ writel(cr2, ®s->cr2); /* START/ReSTART generation */ setbits_le32(®s->cr2, STM32_I2C_CR2_START); } /* * RELOAD mode must be selected if total number of data bytes to be * sent is greater than MAX_LEN */ static void stm32_i2c_handle_reload(struct stm32_i2c *i2c_priv, struct i2c_msg *msg, bool stop) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 cr2 = readl(®s->cr2); cr2 &= ~STM32_I2C_CR2_NBYTES_MASK; if (msg->len > STM32_I2C_MAX_LEN) { cr2 |= STM32_I2C_CR2_NBYTES(STM32_I2C_MAX_LEN); } else { cr2 &= ~STM32_I2C_CR2_RELOAD; cr2 |= STM32_I2C_CR2_NBYTES(msg->len); } writel(cr2, ®s->cr2); } static int stm32_i2c_wait_flags(struct stm32_i2c *i2c_priv, u32 flags, u32 *status) { struct stm32_i2c_regs *regs = i2c_priv->regs; return readl_poll_timeout(®s->isr, *status, *status & flags, USEC_PER_SEC); } static int stm32_i2c_check_end_of_message(struct stm32_i2c *i2c_priv) { struct stm32_i2c_regs *regs = i2c_priv->regs; u32 mask = STM32_I2C_ISR_ERRORS | STM32_I2C_ISR_NACKF | STM32_I2C_ISR_STOPF; struct device_d *dev = &i2c_priv->adapter.dev; u32 status; int ret; ret = stm32_i2c_wait_flags(i2c_priv, mask, &status); if (ret) return ret; if (status & STM32_I2C_ISR_BERR) { dev_dbg(dev, "Bus error\n"); /* Clear BERR flag */ setbits_le32(®s->icr, STM32_I2C_ICR_BERRCF); return -EIO; } if (status & STM32_I2C_ISR_ARLO) { dev_dbg(dev, "Arbitration lost\n"); /* Clear ARLO flag */ setbits_le32(®s->icr, STM32_I2C_ICR_ARLOCF); return -EAGAIN; } if (status & STM32_I2C_ISR_NACKF) { dev_dbg(dev, "Receive NACK\n"); /* Clear NACK flag */ setbits_le32(®s->icr, STM32_I2C_ICR_NACKCF); /* Wait until STOPF flag is set */ mask = STM32_I2C_ISR_STOPF; ret = stm32_i2c_wait_flags(i2c_priv, mask, &status); if (ret) return ret; ret = -EIO; } if (status & STM32_I2C_ISR_STOPF) { /* Clear STOP flag */ setbits_le32(®s->icr, STM32_I2C_ICR_STOPCF); /* Clear control register 2 */ setbits_le32(®s->cr2, STM32_I2C_CR2_RESET_MASK); } return ret; } static int stm32_i2c_message_xfer(struct stm32_i2c *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 ret = 0; /* Add errors */ mask |= STM32_I2C_ISR_ERRORS; stm32_i2c_message_start(i2c_priv, msg, stop); while (len) { /* * Wait until TXIS/NACKF/BERR/ARLO flags or * RXNE/BERR/ARLO flags are set */ ret = stm32_i2c_wait_flags(i2c_priv, mask, &status); if (ret) break; if (status & (STM32_I2C_ISR_NACKF | STM32_I2C_ISR_ERRORS)) break; if (status & STM32_I2C_ISR_RXNE) { *buf++ = readb(®s->rxdr); len--; bytes_to_rw--; } if (status & STM32_I2C_ISR_TXIS) { writeb(*buf++, ®s->txdr); len--; bytes_to_rw--; } if (!bytes_to_rw && 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); 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); } else if (!bytes_to_rw) { /* Wait until TC flag is set */ mask = STM32_I2C_ISR_TC; ret = stm32_i2c_wait_flags(i2c_priv, mask, &status); if (ret) break; if (!stop) /* Message sent, new message has to be sent */ return 0; } } /* End of transfer, send stop condition */ mask = STM32_I2C_CR2_STOP; setbits_le32(®s->cr2, mask); return stm32_i2c_check_end_of_message(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; ret = stm32_i2c_check_device_busy(i2c_priv); if (ret) return -EBUSY; for (i = 0; i < nmsgs; i++) { ret = stm32_i2c_message_xfer(i2c_priv, &msg[i], i == nmsgs - 1); if (ret) return ret; } return nmsgs; } static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup, 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; 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; } sdadel_min = i2c_specs[setup->speed].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 - af_delay_max - (setup->dnf + 4) * i2cclk; scldel_min = setup->timings.scl_rise_ns + i2c_specs[setup->speed].sudat_min; if (sdadel_min < 0) sdadel_min = 0; if (sdadel_max < 0) sdadel_max = 0; pr_debug("SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n", sdadel_min, sdadel_max, scldel_min); /* 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; if (scldel < scldel_min) continue; for (a = 0; a < STM32_SDADEL_MAX; a++) { u32 sdadel = (a * (p + 1) + 1) * i2cclk; if (((sdadel >= sdadel_min) && (sdadel <= sdadel_max)) && (p != p_prev)) { v = calloc(1, sizeof(*v)); if (!v) return -ENOMEM; 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)) ret = -EPERM; return ret; } static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup, 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 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 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; 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; /* * Among Prescaler possibilities discovered above figures out SCL Low * and High Period. Provided: * - SCL Low Period has to be higher than Low Period of the SCL Clock * 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 High Period of the SCL Clock * 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 < STM32_SCLL_MAX; l++) { u32 tscl_l = (l + 1) * prescaler + tsync; if ((tscl_l < i2c_specs[setup->speed].l_min) || (i2cclk >= ((tscl_l - af_delay_min - dnf_delay) / 4))) { continue; } 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; if ((tscl >= clk_min) && (tscl <= clk_max) && (tscl_h >= i2c_specs[setup->speed].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; sol_found = true; memcpy(s, v, sizeof(*s)); } } } } } if (!sol_found) ret = -EPERM; return ret; } static int stm32_i2c_compute_timing(struct stm32_i2c *i2c_priv, struct stm32_i2c_setup *setup, struct stm32_i2c_timings *output) { struct device_d *dev = &i2c_priv->adapter.dev; struct stm32_i2c_timings *v, *_v; struct list_head solutions; 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); 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)) { 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); return -EINVAL; } 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); 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"); goto exit; } ret = stm32_i2c_choose_solution(setup, &solutions, output); if (ret) { if (ret == -EPERM) dev_err(dev, "no solution at all\n"); goto exit; } dev_dbg(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); free(v); } return ret; } static int stm32_i2c_setup_timing(struct stm32_i2c *i2c_priv, enum stm32_i2c_speed speed, struct stm32_i2c_timings *timing) { struct device_d *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->clock_src = clk_get_rate(i2c_priv->clk); if (!setup->clock_src) { dev_err(dev, "clock rate is 0\n"); return -EINVAL; } do { ret = stm32_i2c_compute_timing(i2c_priv, setup, 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; dev_dbg(dev, "downgrade I2C Speed Freq to (%i)\n", i2c_specs[setup->speed].rate); } else { break; } } } while (ret); if (ret) { dev_err(dev, "impossible to compute I2C timings.\n"); 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 Rise(%i) and Fall(%i) Time\n", 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); return 0; } static int stm32_i2c_hw_config(struct stm32_i2c *i2c_priv, enum stm32_i2c_speed speed) { 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); if (ret) return ret; /* Disable I2C */ clrbits_le32(®s->cr1, STM32_I2C_CR1_PE); /* Timing settings */ timing |= STM32_I2C_TIMINGR_PRESC(t.presc); timing |= STM32_I2C_TIMINGR_SCLDEL(t.scldel); timing |= STM32_I2C_TIMINGR_SDADEL(t.sdadel); timing |= STM32_I2C_TIMINGR_SCLH(t.sclh); timing |= STM32_I2C_TIMINGR_SCLL(t.scll); writel(timing, ®s->timingr); /* Enable I2C */ if (i2c_priv->setup.analog_filter) clrbits_le32(®s->cr1, STM32_I2C_CR1_ANFOFF); else setbits_le32(®s->cr1, STM32_I2C_CR1_ANFOFF); setbits_le32(®s->cr1, STM32_I2C_CR1_PE); return 0; } static int stm32_i2c_set_bus_speed(struct stm32_i2c *i2c_priv, unsigned speed) { struct device_d *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); return -EINVAL; } return stm32_i2c_hw_config(i2c_priv, stm32_speed); } static int __init stm32_i2c_probe(struct device_d *dev) { struct resource *iores; struct stm32_i2c *stm32_i2c; struct i2c_platform_data *pdata; struct reset_control *rst; 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); if (IS_ERR(stm32_i2c->clk)) return PTR_ERR(stm32_i2c->clk); clk_enable(stm32_i2c->clk); rst = reset_control_get(dev, NULL); if (IS_ERR(rst)) return PTR_ERR(rst); reset_control_assert(rst); udelay(2); reset_control_deassert(rst); ret = dev_get_drvdata(dev, (const void **)&setup); 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 */ i2c_parse_fw_timings(dev, timings, false); if (!timings->bus_freq_hz) timings->bus_freq_hz = STANDARD_RATE; if (!timings->scl_rise_ns) timings->scl_rise_ns = STM32_I2C_RISE_TIME_DEFAULT; if (!timings->scl_fall_ns) timings->scl_fall_ns = STM32_I2C_FALL_TIME_DEFAULT; /* Setup stm32_i2c driver structure */ stm32_i2c->adapter.master_xfer = stm32_i2c_xfer; stm32_i2c->adapter.nr = dev->id; stm32_i2c->adapter.dev.parent = dev; stm32_i2c->adapter.dev.device_node = dev->device_node; iores = dev_request_mem_resource(dev, 0); if (IS_ERR(iores)) return PTR_ERR(iores); stm32_i2c->regs = IOMEM(iores->start); if (pdata && pdata->bitrate) timings->bus_freq_hz = pdata->bitrate; ret = stm32_i2c_set_bus_speed(stm32_i2c, timings->bus_freq_hz); if (ret) return ret; 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, }, { /* sentinel */ } }; static struct driver_d stm32_i2c_driver = { .probe = stm32_i2c_probe, .name = "stm32f7-i2c", .of_compatible = DRV_OF_COMPAT(stm32_i2c_dt_ids), }; coredevice_platform_driver(stm32_i2c_driver);