// SPDX-License-Identifier: GPL-2.0+ /* * (C) Copyright 2009 * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com. */ #include #include #include #include #include #include #include #include #include "designware_i2c.h" #include #include #ifdef CONFIG_SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable) { u32 ena = enable ? IC_ENABLE_0B : 0; writel(ena, &i2c_base->ic_enable); return 0; } #else static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable) { u32 ena = enable ? IC_ENABLE_0B : 0; int timeout = 100; do { writel(ena, &i2c_base->ic_enable); if ((readl(&i2c_base->ic_enable_status) & IC_ENABLE_0B) == ena) return 0; /* * Wait 10 times the signaling period of the highest I2C * transfer supported by the driver (for 400KHz this is * 25us) as described in the DesignWare I2C databook. */ udelay(25); } while (timeout--); printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis"); return -ETIMEDOUT; } #endif /* High and low times in different speed modes (in ns) */ enum { /* SDA Hold Time */ DEFAULT_SDA_HOLD_TIME = 300, }; /** * calc_counts() - Convert a period to a number of IC clk cycles * * @ic_clk: Input clock in Hz * @period_ns: Period to represent, in ns * @return calculated count */ static uint calc_counts(uint ic_clk, uint period_ns) { return DIV_ROUND_UP(ic_clk / 1000 * period_ns, NANO_TO_KILO); } /** * struct i2c_mode_info - Information about an I2C speed mode * * Each speed mode has its own characteristics. This struct holds these to aid * calculations in dw_i2c_calc_timing(). * * @speed: Speed in Hz * @min_scl_lowtime_ns: Minimum value for SCL low period in ns * @min_scl_hightime_ns: Minimum value for SCL high period in ns * @def_rise_time_ns: Default rise time in ns * @def_fall_time_ns: Default fall time in ns */ struct i2c_mode_info { int speed; int min_scl_hightime_ns; int min_scl_lowtime_ns; int def_rise_time_ns; int def_fall_time_ns; }; static const struct i2c_mode_info info_for_mode[] = { [IC_SPEED_MODE_STANDARD] = { I2C_SPEED_STANDARD_RATE, MIN_SS_SCL_HIGHTIME, MIN_SS_SCL_LOWTIME, 1000, 300, }, [IC_SPEED_MODE_FAST] = { I2C_SPEED_FAST_RATE, MIN_FS_SCL_HIGHTIME, MIN_FS_SCL_LOWTIME, 300, 300, }, [IC_SPEED_MODE_FAST_PLUS] = { I2C_SPEED_FAST_PLUS_RATE, MIN_FP_SCL_HIGHTIME, MIN_FP_SCL_LOWTIME, 260, 500, }, [IC_SPEED_MODE_HIGH] = { I2C_SPEED_HIGH_RATE, MIN_HS_SCL_HIGHTIME, MIN_HS_SCL_LOWTIME, 120, 120, }, }; /** * dw_i2c_calc_timing() - Calculate the timings to use for a bus * * @priv: Bus private information (NULL if not using driver model) * @mode: Speed mode to use * @ic_clk: IC clock speed in Hz * @spk_cnt: Spike-suppression count * @config: Returns value to use * @return 0 if OK, -EINVAL if the calculation failed due to invalid data */ static int dw_i2c_calc_timing(struct dw_i2c *priv, enum i2c_speed_mode mode, int ic_clk, int spk_cnt, struct dw_i2c_speed_config *config) { int fall_cnt, rise_cnt, min_tlow_cnt, min_thigh_cnt; int hcnt, lcnt, period_cnt, diff, tot; int sda_hold_time_ns, scl_rise_time_ns, scl_fall_time_ns; const struct i2c_mode_info *info; /* * Find the period, rise, fall, min tlow, and min thigh in terms of * counts of the IC clock */ info = &info_for_mode[mode]; period_cnt = ic_clk / info->speed; scl_rise_time_ns = priv && priv->scl_rise_time_ns ? priv->scl_rise_time_ns : info->def_rise_time_ns; scl_fall_time_ns = priv && priv->scl_fall_time_ns ? priv->scl_fall_time_ns : info->def_fall_time_ns; rise_cnt = calc_counts(ic_clk, scl_rise_time_ns); fall_cnt = calc_counts(ic_clk, scl_fall_time_ns); min_tlow_cnt = calc_counts(ic_clk, info->min_scl_lowtime_ns); min_thigh_cnt = calc_counts(ic_clk, info->min_scl_hightime_ns); debug("dw_i2c: period %d rise %d fall %d tlow %d thigh %d spk %d\n", period_cnt, rise_cnt, fall_cnt, min_tlow_cnt, min_thigh_cnt, spk_cnt); /* * Back-solve for hcnt and lcnt according to the following equations: * SCL_High_time = [(HCNT + IC_*_SPKLEN + 7) * ic_clk] + SCL_Fall_time * SCL_Low_time = [(LCNT + 1) * ic_clk] - SCL_Fall_time + SCL_Rise_time */ hcnt = min_thigh_cnt - fall_cnt - 7 - spk_cnt; lcnt = min_tlow_cnt - rise_cnt + fall_cnt - 1; if (hcnt < 0 || lcnt < 0) { debug("dw_i2c: bad counts. hcnt = %d lcnt = %d\n", hcnt, lcnt); return -EINVAL; } /* * Now add things back up to ensure the period is hit. If it is off, * split the difference and bias to lcnt for remainder */ tot = hcnt + lcnt + 7 + spk_cnt + rise_cnt + 1; if (tot < period_cnt) { diff = (period_cnt - tot) / 2; hcnt += diff; lcnt += diff; tot = hcnt + lcnt + 7 + spk_cnt + rise_cnt + 1; lcnt += period_cnt - tot; } config->scl_lcnt = lcnt; config->scl_hcnt = hcnt; /* Use internal default unless other value is specified */ sda_hold_time_ns = priv && priv->sda_hold_time_ns ? priv->sda_hold_time_ns : DEFAULT_SDA_HOLD_TIME; config->sda_hold = calc_counts(ic_clk, sda_hold_time_ns); debug("dw_i2c: hcnt = %d lcnt = %d sda hold = %d\n", hcnt, lcnt, config->sda_hold); return 0; } static int calc_bus_speed(struct dw_i2c *priv, int speed, ulong bus_clk, struct dw_i2c_speed_config *config) { const struct dw_scl_sda_cfg *scl_sda_cfg = NULL; struct i2c_regs *regs = priv->regs; enum i2c_speed_mode i2c_spd; int spk_cnt; int ret; if (priv) scl_sda_cfg = priv->scl_sda_cfg; /* Allow high speed if there is no config, or the config allows it */ if (speed >= I2C_SPEED_HIGH_RATE && (!scl_sda_cfg || scl_sda_cfg->has_high_speed)) i2c_spd = IC_SPEED_MODE_HIGH; else if (speed >= I2C_SPEED_FAST_PLUS_RATE) i2c_spd = IC_SPEED_MODE_FAST_PLUS; else if (speed >= I2C_SPEED_FAST_RATE) i2c_spd = IC_SPEED_MODE_FAST; else i2c_spd = IC_SPEED_MODE_STANDARD; /* Get the proper spike-suppression count based on target speed */ if (!priv || !priv->has_spk_cnt) spk_cnt = 0; else if (i2c_spd >= IC_SPEED_MODE_HIGH) spk_cnt = readl(®s->hs_spklen); else spk_cnt = readl(®s->fs_spklen); if (scl_sda_cfg) { config->sda_hold = scl_sda_cfg->sda_hold; if (i2c_spd == IC_SPEED_MODE_STANDARD) { config->scl_hcnt = scl_sda_cfg->ss_hcnt; config->scl_lcnt = scl_sda_cfg->ss_lcnt; } else { config->scl_hcnt = scl_sda_cfg->fs_hcnt; config->scl_lcnt = scl_sda_cfg->fs_lcnt; } } else { ret = dw_i2c_calc_timing(priv, i2c_spd, bus_clk, spk_cnt, config); if (ret) return log_msg_ret("gen_confg", ret); } config->speed_mode = i2c_spd; return 0; } /* * _dw_i2c_set_bus_speed - Set the i2c speed * @speed: required i2c speed * * Set the i2c speed. */ static int _dw_i2c_set_bus_speed(struct dw_i2c *priv, struct i2c_regs *i2c_base, unsigned int speed, unsigned int bus_clk) { struct dw_i2c_speed_config config; unsigned int cntl; unsigned int ena; int ret; ret = calc_bus_speed(priv, speed, bus_clk, &config); if (ret) return ret; /* Get enable setting for restore later */ ena = readl(&i2c_base->ic_enable) & IC_ENABLE_0B; /* to set speed cltr must be disabled */ dw_i2c_enable(i2c_base, false); cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK)); switch (config.speed_mode) { case IC_SPEED_MODE_HIGH: cntl |= IC_CON_SPD_HS; writel(config.scl_hcnt, &i2c_base->ic_hs_scl_hcnt); writel(config.scl_lcnt, &i2c_base->ic_hs_scl_lcnt); break; case IC_SPEED_MODE_STANDARD: cntl |= IC_CON_SPD_SS; writel(config.scl_hcnt, &i2c_base->ic_ss_scl_hcnt); writel(config.scl_lcnt, &i2c_base->ic_ss_scl_lcnt); break; case IC_SPEED_MODE_FAST_PLUS: case IC_SPEED_MODE_FAST: default: cntl |= IC_CON_SPD_FS; writel(config.scl_hcnt, &i2c_base->ic_fs_scl_hcnt); writel(config.scl_lcnt, &i2c_base->ic_fs_scl_lcnt); break; } writel(cntl, &i2c_base->ic_con); /* Configure SDA Hold Time if required */ if (config.sda_hold) writel(config.sda_hold, &i2c_base->ic_sda_hold); /* Restore back i2c now speed set */ if (ena == IC_ENABLE_0B) dw_i2c_enable(i2c_base, true); return 0; } /* * i2c_setaddress - Sets the target slave address * @i2c_addr: target i2c address * * Sets the target slave address. */ static void i2c_setaddress(struct i2c_regs *i2c_base, unsigned int i2c_addr) { /* Disable i2c */ dw_i2c_enable(i2c_base, false); writel(i2c_addr, &i2c_base->ic_tar); /* Enable i2c */ dw_i2c_enable(i2c_base, true); } /* * i2c_flush_rxfifo - Flushes the i2c RX FIFO * * Flushes the i2c RX FIFO */ static void i2c_flush_rxfifo(struct i2c_regs *i2c_base) { while (readl(&i2c_base->ic_status) & IC_STATUS_RFNE) readl(&i2c_base->ic_cmd_data); } /* * i2c_wait_for_bb - Waits for bus busy * * Waits for bus busy */ static int i2c_wait_for_bb(struct i2c_regs *i2c_base) { unsigned long start_time_bb = get_timer(0); while ((readl(&i2c_base->ic_status) & IC_STATUS_MA) || !(readl(&i2c_base->ic_status) & IC_STATUS_TFE)) { /* Evaluate timeout */ if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB)) return 1; } return 0; } static int i2c_xfer_init(struct i2c_regs *i2c_base, uchar chip, uint addr, int alen) { if (i2c_wait_for_bb(i2c_base)) return 1; i2c_setaddress(i2c_base, chip); while (alen) { alen--; /* high byte address going out first */ writel((addr >> (alen * 8)) & 0xff, &i2c_base->ic_cmd_data); } return 0; } static int i2c_xfer_finish(struct i2c_regs *i2c_base) { ulong start_stop_det = get_timer(0); while (1) { if ((readl(&i2c_base->ic_raw_intr_stat) & IC_STOP_DET)) { readl(&i2c_base->ic_clr_stop_det); break; } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) { break; } } if (i2c_wait_for_bb(i2c_base)) { printf("Timed out waiting for bus\n"); return 1; } i2c_flush_rxfifo(i2c_base); return 0; } /* * i2c_read - Read from i2c memory * @chip: target i2c address * @addr: address to read from * @alen: * @buffer: buffer for read data * @len: no of bytes to be read * * Read from i2c memory. */ static int __dw_i2c_read(struct i2c_regs *i2c_base, u8 dev, uint addr, int alen, u8 *buffer, int len) { unsigned long start_time_rx; unsigned int active = 0; #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW /* * EEPROM chips that implement "address overflow" are ones * like Catalyst 24WC04/08/16 which has 9/10/11 bits of * address and the extra bits end up in the "chip address" * bit slots. This makes a 24WC08 (1Kbyte) chip look like * four 256 byte chips. * * Note that we consider the length of the address field to * still be one byte because the extra address bits are * hidden in the chip address. */ dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW); addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8)); debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev, addr); #endif if (i2c_xfer_init(i2c_base, dev, addr, alen)) return 1; start_time_rx = get_timer(0); while (len) { if (!active) { /* * Avoid writing to ic_cmd_data multiple times * in case this loop spins too quickly and the * ic_status RFNE bit isn't set after the first * write. Subsequent writes to ic_cmd_data can * trigger spurious i2c transfer. */ if (len == 1) writel(IC_CMD | IC_STOP, &i2c_base->ic_cmd_data); else writel(IC_CMD, &i2c_base->ic_cmd_data); active = 1; } if (readl(&i2c_base->ic_status) & IC_STATUS_RFNE) { *buffer++ = (uchar)readl(&i2c_base->ic_cmd_data); len--; start_time_rx = get_timer(0); active = 0; } else if (get_timer(start_time_rx) > I2C_BYTE_TO) { return 1; } } return i2c_xfer_finish(i2c_base); } /* * i2c_write - Write to i2c memory * @chip: target i2c address * @addr: address to read from * @alen: * @buffer: buffer for read data * @len: no of bytes to be read * * Write to i2c memory. */ static int __dw_i2c_write(struct i2c_regs *i2c_base, u8 dev, uint addr, int alen, u8 *buffer, int len) { int nb = len; unsigned long start_time_tx; #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW /* * EEPROM chips that implement "address overflow" are ones * like Catalyst 24WC04/08/16 which has 9/10/11 bits of * address and the extra bits end up in the "chip address" * bit slots. This makes a 24WC08 (1Kbyte) chip look like * four 256 byte chips. * * Note that we consider the length of the address field to * still be one byte because the extra address bits are * hidden in the chip address. */ dev |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW); addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8)); debug("%s: fix addr_overflow: dev %02x addr %02x\n", __func__, dev, addr); #endif if (i2c_xfer_init(i2c_base, dev, addr, alen)) return 1; start_time_tx = get_timer(0); while (len) { if (readl(&i2c_base->ic_status) & IC_STATUS_TFNF) { if (--len == 0) { writel(*buffer | IC_STOP, &i2c_base->ic_cmd_data); } else { writel(*buffer, &i2c_base->ic_cmd_data); } buffer++; start_time_tx = get_timer(0); } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) { printf("Timed out. i2c write Failed\n"); return 1; } } return i2c_xfer_finish(i2c_base); } /* * __dw_i2c_init - Init function * @speed: required i2c speed * @slaveaddr: slave address for the device * * Initialization function. */ static int __dw_i2c_init(struct i2c_regs *i2c_base, int speed, int slaveaddr) { int ret; /* Disable i2c */ ret = dw_i2c_enable(i2c_base, false); if (ret) return ret; writel(IC_CON_SD | IC_CON_RE | IC_CON_SPD_FS | IC_CON_MM, &i2c_base->ic_con); writel(IC_RX_TL, &i2c_base->ic_rx_tl); writel(IC_TX_TL, &i2c_base->ic_tx_tl); writel(IC_STOP_DET, &i2c_base->ic_intr_mask); #ifndef CONFIG_DM_I2C _dw_i2c_set_bus_speed(NULL, i2c_base, speed, IC_CLK); writel(slaveaddr, &i2c_base->ic_sar); #endif /* Enable i2c */ ret = dw_i2c_enable(i2c_base, true); if (ret) return ret; return 0; } #ifndef CONFIG_DM_I2C /* * The legacy I2C functions. These need to get removed once * all users of this driver are converted to DM. */ static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap) { switch (adap->hwadapnr) { #if CONFIG_SYS_I2C_BUS_MAX >= 4 case 3: return (struct i2c_regs *)CONFIG_SYS_I2C_BASE3; #endif #if CONFIG_SYS_I2C_BUS_MAX >= 3 case 2: return (struct i2c_regs *)CONFIG_SYS_I2C_BASE2; #endif #if CONFIG_SYS_I2C_BUS_MAX >= 2 case 1: return (struct i2c_regs *)CONFIG_SYS_I2C_BASE1; #endif case 0: return (struct i2c_regs *)CONFIG_SYS_I2C_BASE; default: printf("Wrong I2C-adapter number %d\n", adap->hwadapnr); } return NULL; } static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap, unsigned int speed) { adap->speed = speed; return _dw_i2c_set_bus_speed(NULL, i2c_get_base(adap), speed, IC_CLK); } static void dw_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr) { __dw_i2c_init(i2c_get_base(adap), speed, slaveaddr); } static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr, int alen, u8 *buffer, int len) { return __dw_i2c_read(i2c_get_base(adap), dev, addr, alen, buffer, len); } static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr, int alen, u8 *buffer, int len) { return __dw_i2c_write(i2c_get_base(adap), dev, addr, alen, buffer, len); } /* dw_i2c_probe - Probe the i2c chip */ static int dw_i2c_probe(struct i2c_adapter *adap, u8 dev) { struct i2c_regs *i2c_base = i2c_get_base(adap); u32 tmp; int ret; /* * Try to read the first location of the chip. */ ret = __dw_i2c_read(i2c_base, dev, 0, 1, (uchar *)&tmp, 1); if (ret) dw_i2c_init(adap, adap->speed, adap->slaveaddr); return ret; } U_BOOT_I2C_ADAP_COMPLETE(dw_0, dw_i2c_init, dw_i2c_probe, dw_i2c_read, dw_i2c_write, dw_i2c_set_bus_speed, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE, 0) #if CONFIG_SYS_I2C_BUS_MAX >= 2 U_BOOT_I2C_ADAP_COMPLETE(dw_1, dw_i2c_init, dw_i2c_probe, dw_i2c_read, dw_i2c_write, dw_i2c_set_bus_speed, CONFIG_SYS_I2C_SPEED1, CONFIG_SYS_I2C_SLAVE1, 1) #endif #if CONFIG_SYS_I2C_BUS_MAX >= 3 U_BOOT_I2C_ADAP_COMPLETE(dw_2, dw_i2c_init, dw_i2c_probe, dw_i2c_read, dw_i2c_write, dw_i2c_set_bus_speed, CONFIG_SYS_I2C_SPEED2, CONFIG_SYS_I2C_SLAVE2, 2) #endif #if CONFIG_SYS_I2C_BUS_MAX >= 4 U_BOOT_I2C_ADAP_COMPLETE(dw_3, dw_i2c_init, dw_i2c_probe, dw_i2c_read, dw_i2c_write, dw_i2c_set_bus_speed, CONFIG_SYS_I2C_SPEED3, CONFIG_SYS_I2C_SLAVE3, 3) #endif #else /* CONFIG_DM_I2C */ /* The DM I2C functions */ static int designware_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) { struct dw_i2c *i2c = dev_get_priv(bus); int ret; debug("i2c_xfer: %d messages\n", nmsgs); for (; nmsgs > 0; nmsgs--, msg++) { debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len); if (msg->flags & I2C_M_RD) { ret = __dw_i2c_read(i2c->regs, msg->addr, 0, 0, msg->buf, msg->len); } else { ret = __dw_i2c_write(i2c->regs, msg->addr, 0, 0, msg->buf, msg->len); } if (ret) { debug("i2c_write: error sending\n"); return -EREMOTEIO; } } return 0; } static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) { struct dw_i2c *i2c = dev_get_priv(bus); ulong rate; #if CONFIG_IS_ENABLED(CLK) rate = clk_get_rate(&i2c->clk); if (IS_ERR_VALUE(rate)) return -EINVAL; #else rate = IC_CLK; #endif return _dw_i2c_set_bus_speed(i2c, i2c->regs, speed, rate); } static int designware_i2c_probe_chip(struct udevice *bus, uint chip_addr, uint chip_flags) { struct dw_i2c *i2c = dev_get_priv(bus); struct i2c_regs *i2c_base = i2c->regs; u32 tmp; int ret; /* Try to read the first location of the chip */ ret = __dw_i2c_read(i2c_base, chip_addr, 0, 1, (uchar *)&tmp, 1); if (ret) __dw_i2c_init(i2c_base, 0, 0); return ret; } int designware_i2c_ofdata_to_platdata(struct udevice *bus) { struct dw_i2c *priv = dev_get_priv(bus); int ret; if (!priv->regs) priv->regs = (struct i2c_regs *)devfdt_get_addr_ptr(bus); dev_read_u32(bus, "i2c-scl-rising-time-ns", &priv->scl_rise_time_ns); dev_read_u32(bus, "i2c-scl-falling-time-ns", &priv->scl_fall_time_ns); dev_read_u32(bus, "i2c-sda-hold-time-ns", &priv->sda_hold_time_ns); ret = reset_get_bulk(bus, &priv->resets); if (ret) dev_warn(bus, "Can't get reset: %d\n", ret); else reset_deassert_bulk(&priv->resets); #if CONFIG_IS_ENABLED(CLK) ret = clk_get_by_index(bus, 0, &priv->clk); if (ret) return ret; ret = clk_enable(&priv->clk); if (ret && ret != -ENOSYS && ret != -ENOTSUPP) { clk_free(&priv->clk); dev_err(bus, "failed to enable clock\n"); return ret; } #endif return 0; } int designware_i2c_probe(struct udevice *bus) { struct dw_i2c *priv = dev_get_priv(bus); return __dw_i2c_init(priv->regs, 0, 0); } int designware_i2c_remove(struct udevice *dev) { struct dw_i2c *priv = dev_get_priv(dev); #if CONFIG_IS_ENABLED(CLK) clk_disable(&priv->clk); clk_free(&priv->clk); #endif return reset_release_bulk(&priv->resets); } const struct dm_i2c_ops designware_i2c_ops = { .xfer = designware_i2c_xfer, .probe_chip = designware_i2c_probe_chip, .set_bus_speed = designware_i2c_set_bus_speed, }; static const struct udevice_id designware_i2c_ids[] = { { .compatible = "snps,designware-i2c" }, { } }; U_BOOT_DRIVER(i2c_designware) = { .name = "i2c_designware", .id = UCLASS_I2C, .of_match = designware_i2c_ids, .ofdata_to_platdata = designware_i2c_ofdata_to_platdata, .probe = designware_i2c_probe, .priv_auto_alloc_size = sizeof(struct dw_i2c), .remove = designware_i2c_remove, .flags = DM_FLAG_OS_PREPARE, .ops = &designware_i2c_ops, }; #endif /* CONFIG_DM_I2C */