/* * max8973-regulator.c -- Maxim max8973 * * Regulator driver for MAXIM 8973 DC-DC step-down switching regulator. * * Copyright (c) 2012, NVIDIA Corporation. * * Author: Laxman Dewangan * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation version 2. * * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind, * whether express or implied; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA * 02111-1307, USA */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Register definitions */ #define MAX8973_VOUT 0x0 #define MAX8973_VOUT_DVS 0x1 #define MAX8973_CONTROL1 0x2 #define MAX8973_CONTROL2 0x3 #define MAX8973_CHIPID1 0x4 #define MAX8973_CHIPID2 0x5 #define MAX8973_MAX_VOUT_REG 2 /* MAX8973_VOUT */ #define MAX8973_VOUT_ENABLE BIT(7) #define MAX8973_VOUT_MASK 0x7F /* MAX8973_VOUT_DVS */ #define MAX8973_DVS_VOUT_MASK 0x7F /* MAX8973_CONTROL1 */ #define MAX8973_SNS_ENABLE BIT(7) #define MAX8973_FPWM_EN_M BIT(6) #define MAX8973_NFSR_ENABLE BIT(5) #define MAX8973_AD_ENABLE BIT(4) #define MAX8973_BIAS_ENABLE BIT(3) #define MAX8973_FREQSHIFT_9PER BIT(2) #define MAX8973_RAMP_12mV_PER_US 0x0 #define MAX8973_RAMP_25mV_PER_US 0x1 #define MAX8973_RAMP_50mV_PER_US 0x2 #define MAX8973_RAMP_200mV_PER_US 0x3 #define MAX8973_RAMP_MASK 0x3 /* MAX8973_CONTROL2 */ #define MAX8973_WDTMR_ENABLE BIT(6) #define MAX8973_DISCH_ENBABLE BIT(5) #define MAX8973_FT_ENABLE BIT(4) #define MAX8973_CKKADV_TRIP_MASK 0xC #define MAX8973_CKKADV_TRIP_DISABLE 0xC #define MAX8973_CKKADV_TRIP_75mV_PER_US 0x0 #define MAX8973_CKKADV_TRIP_150mV_PER_US 0x4 #define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS 0x8 #define MAX8973_CONTROL_CLKADV_TRIP_MASK 0x00030000 #define MAX8973_INDUCTOR_MIN_30_PER 0x0 #define MAX8973_INDUCTOR_NOMINAL 0x1 #define MAX8973_INDUCTOR_PLUS_30_PER 0x2 #define MAX8973_INDUCTOR_PLUS_60_PER 0x3 #define MAX8973_CONTROL_INDUCTOR_VALUE_MASK 0x00300000 #define MAX8973_MIN_VOLATGE 606250 #define MAX8973_MAX_VOLATGE 1400000 #define MAX8973_VOLATGE_STEP 6250 #define MAX8973_BUCK_N_VOLTAGE 0x80 enum device_id { MAX8973, MAX77621 }; /* Maxim 8973 chip information */ struct max8973_chip { struct device *dev; struct regulator_desc desc; struct regmap *regmap; bool enable_external_control; int enable_gpio; int dvs_gpio; int lru_index[MAX8973_MAX_VOUT_REG]; int curr_vout_val[MAX8973_MAX_VOUT_REG]; int curr_vout_reg; int curr_gpio_val; struct regulator_ops ops; enum device_id id; }; /* * find_voltage_set_register: Find new voltage configuration register (VOUT). * The finding of the new VOUT register will be based on the LRU mechanism. * Each VOUT register will have different voltage configured . This * Function will look if any of the VOUT register have requested voltage set * or not. * - If it is already there then it will make that register as most * recently used and return as found so that caller need not to set * the VOUT register but need to set the proper gpios to select this * VOUT register. * - If requested voltage is not found then it will use the least * recently mechanism to get new VOUT register for new configuration * and will return not_found so that caller need to set new VOUT * register and then gpios (both). */ static bool find_voltage_set_register(struct max8973_chip *tps, int req_vsel, int *vout_reg, int *gpio_val) { int i; bool found = false; int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1]; int found_index = MAX8973_MAX_VOUT_REG - 1; for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) { if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) { new_vout_reg = tps->lru_index[i]; found_index = i; found = true; goto update_lru_index; } } update_lru_index: for (i = found_index; i > 0; i--) tps->lru_index[i] = tps->lru_index[i - 1]; tps->lru_index[0] = new_vout_reg; *gpio_val = new_vout_reg; *vout_reg = MAX8973_VOUT + new_vout_reg; return found; } static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev) { struct max8973_chip *max = rdev_get_drvdata(rdev); unsigned int data; int ret; ret = regmap_read(max->regmap, max->curr_vout_reg, &data); if (ret < 0) { dev_err(max->dev, "register %d read failed, err = %d\n", max->curr_vout_reg, ret); return ret; } return data & MAX8973_VOUT_MASK; } static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev, unsigned vsel) { struct max8973_chip *max = rdev_get_drvdata(rdev); int ret; bool found = false; int vout_reg = max->curr_vout_reg; int gpio_val = max->curr_gpio_val; /* * If gpios are available to select the VOUT register then least * recently used register for new configuration. */ if (gpio_is_valid(max->dvs_gpio)) found = find_voltage_set_register(max, vsel, &vout_reg, &gpio_val); if (!found) { ret = regmap_update_bits(max->regmap, vout_reg, MAX8973_VOUT_MASK, vsel); if (ret < 0) { dev_err(max->dev, "register %d update failed, err %d\n", vout_reg, ret); return ret; } max->curr_vout_reg = vout_reg; max->curr_vout_val[gpio_val] = vsel; } /* Select proper VOUT register vio gpios */ if (gpio_is_valid(max->dvs_gpio)) { gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1); max->curr_gpio_val = gpio_val; } return 0; } static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode) { struct max8973_chip *max = rdev_get_drvdata(rdev); int ret; int pwm; /* Enable force PWM mode in FAST mode only. */ switch (mode) { case REGULATOR_MODE_FAST: pwm = MAX8973_FPWM_EN_M; break; case REGULATOR_MODE_NORMAL: pwm = 0; break; default: return -EINVAL; } ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1, MAX8973_FPWM_EN_M, pwm); if (ret < 0) dev_err(max->dev, "register %d update failed, err %d\n", MAX8973_CONTROL1, ret); return ret; } static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev) { struct max8973_chip *max = rdev_get_drvdata(rdev); unsigned int data; int ret; ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data); if (ret < 0) { dev_err(max->dev, "register %d read failed, err %d\n", MAX8973_CONTROL1, ret); return ret; } return (data & MAX8973_FPWM_EN_M) ? REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL; } static int max8973_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay) { struct max8973_chip *max = rdev_get_drvdata(rdev); unsigned int control; int ret; int ret_val; /* Set ramp delay */ if (ramp_delay < 25000) { control = MAX8973_RAMP_12mV_PER_US; ret_val = 12000; } else if (ramp_delay < 50000) { control = MAX8973_RAMP_25mV_PER_US; ret_val = 25000; } else if (ramp_delay < 200000) { control = MAX8973_RAMP_50mV_PER_US; ret_val = 50000; } else { control = MAX8973_RAMP_200mV_PER_US; ret_val = 200000; } ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1, MAX8973_RAMP_MASK, control); if (ret < 0) dev_err(max->dev, "register %d update failed, %d", MAX8973_CONTROL1, ret); return ret; } static int max8973_set_current_limit(struct regulator_dev *rdev, int min_ua, int max_ua) { struct max8973_chip *max = rdev_get_drvdata(rdev); unsigned int val; int ret; if (max_ua <= 9000000) val = MAX8973_CKKADV_TRIP_75mV_PER_US; else if (max_ua <= 12000000) val = MAX8973_CKKADV_TRIP_150mV_PER_US; else val = MAX8973_CKKADV_TRIP_DISABLE; ret = regmap_update_bits(max->regmap, MAX8973_CONTROL2, MAX8973_CKKADV_TRIP_MASK, val); if (ret < 0) { dev_err(max->dev, "register %d update failed: %d\n", MAX8973_CONTROL2, ret); return ret; } return 0; } static int max8973_get_current_limit(struct regulator_dev *rdev) { struct max8973_chip *max = rdev_get_drvdata(rdev); unsigned int control2; int ret; ret = regmap_read(max->regmap, MAX8973_CONTROL2, &control2); if (ret < 0) { dev_err(max->dev, "register %d read failed: %d\n", MAX8973_CONTROL2, ret); return ret; } switch (control2 & MAX8973_CKKADV_TRIP_MASK) { case MAX8973_CKKADV_TRIP_DISABLE: return 15000000; case MAX8973_CKKADV_TRIP_150mV_PER_US: return 12000000; case MAX8973_CKKADV_TRIP_75mV_PER_US: return 9000000; default: break; } return 9000000; } static const struct regulator_ops max8973_dcdc_ops = { .get_voltage_sel = max8973_dcdc_get_voltage_sel, .set_voltage_sel = max8973_dcdc_set_voltage_sel, .list_voltage = regulator_list_voltage_linear, .set_mode = max8973_dcdc_set_mode, .get_mode = max8973_dcdc_get_mode, .set_voltage_time_sel = regulator_set_voltage_time_sel, .set_ramp_delay = max8973_set_ramp_delay, }; static int max8973_init_dcdc(struct max8973_chip *max, struct max8973_regulator_platform_data *pdata) { int ret; uint8_t control1 = 0; uint8_t control2 = 0; unsigned int data; ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data); if (ret < 0) { dev_err(max->dev, "register %d read failed, err = %d", MAX8973_CONTROL1, ret); return ret; } control1 = data & MAX8973_RAMP_MASK; switch (control1) { case MAX8973_RAMP_12mV_PER_US: max->desc.ramp_delay = 12000; break; case MAX8973_RAMP_25mV_PER_US: max->desc.ramp_delay = 25000; break; case MAX8973_RAMP_50mV_PER_US: max->desc.ramp_delay = 50000; break; case MAX8973_RAMP_200mV_PER_US: max->desc.ramp_delay = 200000; break; } if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE) control1 |= MAX8973_SNS_ENABLE; if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE)) control1 |= MAX8973_NFSR_ENABLE; if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE) control1 |= MAX8973_AD_ENABLE; if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE) { control1 |= MAX8973_BIAS_ENABLE; max->desc.enable_time = 20; } else { max->desc.enable_time = 240; } if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE) control1 |= MAX8973_FREQSHIFT_9PER; if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE)) control2 |= MAX8973_DISCH_ENBABLE; /* Clock advance trip configuration */ switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) { case MAX8973_CONTROL_CLKADV_TRIP_DISABLED: control2 |= MAX8973_CKKADV_TRIP_DISABLE; break; case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US: control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US; break; case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US: control2 |= MAX8973_CKKADV_TRIP_150mV_PER_US; break; case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS: control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS; break; } /* Configure inductor value */ switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) { case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL: control2 |= MAX8973_INDUCTOR_NOMINAL; break; case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER: control2 |= MAX8973_INDUCTOR_MIN_30_PER; break; case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER: control2 |= MAX8973_INDUCTOR_PLUS_30_PER; break; case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER: control2 |= MAX8973_INDUCTOR_PLUS_60_PER; break; } ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1); if (ret < 0) { dev_err(max->dev, "register %d write failed, err = %d", MAX8973_CONTROL1, ret); return ret; } ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2); if (ret < 0) { dev_err(max->dev, "register %d write failed, err = %d", MAX8973_CONTROL2, ret); return ret; } /* If external control is enabled then disable EN bit */ if (max->enable_external_control && (max->id == MAX8973)) { ret = regmap_update_bits(max->regmap, MAX8973_VOUT, MAX8973_VOUT_ENABLE, 0); if (ret < 0) dev_err(max->dev, "register %d update failed, err = %d", MAX8973_VOUT, ret); } return ret; } static const struct regmap_config max8973_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = MAX8973_CHIPID2, .cache_type = REGCACHE_RBTREE, }; static struct max8973_regulator_platform_data *max8973_parse_dt( struct device *dev) { struct max8973_regulator_platform_data *pdata; struct device_node *np = dev->of_node; int ret; u32 pval; bool etr_enable; bool etr_sensitivity_high; pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return NULL; pdata->enable_ext_control = of_property_read_bool(np, "maxim,externally-enable"); pdata->enable_gpio = of_get_named_gpio(np, "maxim,enable-gpio", 0); pdata->dvs_gpio = of_get_named_gpio(np, "maxim,dvs-gpio", 0); ret = of_property_read_u32(np, "maxim,dvs-default-state", &pval); if (!ret) pdata->dvs_def_state = pval; if (of_property_read_bool(np, "maxim,enable-remote-sense")) pdata->control_flags |= MAX8973_CONTROL_REMOTE_SENSE_ENABLE; if (of_property_read_bool(np, "maxim,enable-falling-slew-rate")) pdata->control_flags |= MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE; if (of_property_read_bool(np, "maxim,enable-active-discharge")) pdata->control_flags |= MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE; if (of_property_read_bool(np, "maxim,enable-frequency-shift")) pdata->control_flags |= MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE; if (of_property_read_bool(np, "maxim,enable-bias-control")) pdata->control_flags |= MAX8973_CONTROL_BIAS_ENABLE; etr_enable = of_property_read_bool(np, "maxim,enable-etr"); etr_sensitivity_high = of_property_read_bool(np, "maxim,enable-high-etr-sensitivity"); if (etr_sensitivity_high) etr_enable = true; if (etr_enable) { if (etr_sensitivity_high) pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US; else pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US; } else { pdata->control_flags |= MAX8973_CONTROL_CLKADV_TRIP_DISABLED; } return pdata; } static const struct of_device_id of_max8973_match_tbl[] = { { .compatible = "maxim,max8973", .data = (void *)MAX8973, }, { .compatible = "maxim,max77621", .data = (void *)MAX77621, }, { }, }; MODULE_DEVICE_TABLE(of, of_max8973_match_tbl); static int max8973_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct max8973_regulator_platform_data *pdata; struct regulator_init_data *ridata; struct regulator_config config = { }; struct regulator_dev *rdev; struct max8973_chip *max; bool pdata_from_dt = false; unsigned int chip_id; int ret; pdata = dev_get_platdata(&client->dev); if (!pdata && client->dev.of_node) { pdata = max8973_parse_dt(&client->dev); pdata_from_dt = true; } if (!pdata) { dev_err(&client->dev, "No Platform data"); return -EIO; } if ((pdata->dvs_gpio == -EPROBE_DEFER) || (pdata->enable_gpio == -EPROBE_DEFER)) return -EPROBE_DEFER; max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL); if (!max) return -ENOMEM; max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config); if (IS_ERR(max->regmap)) { ret = PTR_ERR(max->regmap); dev_err(&client->dev, "regmap init failed, err %d\n", ret); return ret; } if (client->dev.of_node) { const struct of_device_id *match; match = of_match_device(of_match_ptr(of_max8973_match_tbl), &client->dev); if (!match) return -ENODATA; max->id = (u32)((uintptr_t)match->data); } else { max->id = id->driver_data; } ret = regmap_read(max->regmap, MAX8973_CHIPID1, &chip_id); if (ret < 0) { dev_err(&client->dev, "register CHIPID1 read failed, %d", ret); return ret; } dev_info(&client->dev, "CHIP-ID OTP: 0x%02x ID_M: 0x%02x\n", (chip_id >> 4) & 0xF, (chip_id >> 1) & 0x7); i2c_set_clientdata(client, max); max->ops = max8973_dcdc_ops; max->dev = &client->dev; max->desc.name = id->name; max->desc.id = 0; max->desc.ops = &max->ops; max->desc.type = REGULATOR_VOLTAGE; max->desc.owner = THIS_MODULE; max->desc.min_uV = MAX8973_MIN_VOLATGE; max->desc.uV_step = MAX8973_VOLATGE_STEP; max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE; max->dvs_gpio = (pdata->dvs_gpio) ? pdata->dvs_gpio : -EINVAL; max->enable_gpio = (pdata->enable_gpio) ? pdata->enable_gpio : -EINVAL; max->enable_external_control = pdata->enable_ext_control; max->curr_gpio_val = pdata->dvs_def_state; max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state; if (gpio_is_valid(max->enable_gpio)) max->enable_external_control = true; max->lru_index[0] = max->curr_vout_reg; if (gpio_is_valid(max->dvs_gpio)) { int gpio_flags; int i; gpio_flags = (pdata->dvs_def_state) ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW; ret = devm_gpio_request_one(&client->dev, max->dvs_gpio, gpio_flags, "max8973-dvs"); if (ret) { dev_err(&client->dev, "gpio_request for gpio %d failed, err = %d\n", max->dvs_gpio, ret); return ret; } /* * Initialize the lru index with vout_reg id * The index 0 will be most recently used and * set with the max->curr_vout_reg */ for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) max->lru_index[i] = i; max->lru_index[0] = max->curr_vout_reg; max->lru_index[max->curr_vout_reg] = 0; } else { /* * If there is no DVS GPIO, the VOUT register * address is fixed. */ max->ops.set_voltage_sel = regulator_set_voltage_sel_regmap; max->ops.get_voltage_sel = regulator_get_voltage_sel_regmap; max->desc.vsel_reg = max->curr_vout_reg; max->desc.vsel_mask = MAX8973_VOUT_MASK; } if (pdata_from_dt) pdata->reg_init_data = of_get_regulator_init_data(&client->dev, client->dev.of_node, &max->desc); ridata = pdata->reg_init_data; switch (max->id) { case MAX8973: if (!pdata->enable_ext_control) { max->desc.enable_reg = MAX8973_VOUT; max->desc.enable_mask = MAX8973_VOUT_ENABLE; max->ops.enable = regulator_enable_regmap; max->ops.disable = regulator_disable_regmap; max->ops.is_enabled = regulator_is_enabled_regmap; break; } if (gpio_is_valid(max->enable_gpio)) { config.ena_gpio_flags = GPIOF_OUT_INIT_LOW; if (ridata && (ridata->constraints.always_on || ridata->constraints.boot_on)) config.ena_gpio_flags = GPIOF_OUT_INIT_HIGH; config.ena_gpio = max->enable_gpio; } break; case MAX77621: if (gpio_is_valid(max->enable_gpio)) { ret = devm_gpio_request_one(&client->dev, max->enable_gpio, GPIOF_OUT_INIT_HIGH, "max8973-en-gpio"); if (ret) { dev_err(&client->dev, "gpio_request for gpio %d failed: %d\n", max->enable_gpio, ret); return ret; } } max->desc.enable_reg = MAX8973_VOUT; max->desc.enable_mask = MAX8973_VOUT_ENABLE; max->ops.enable = regulator_enable_regmap; max->ops.disable = regulator_disable_regmap; max->ops.is_enabled = regulator_is_enabled_regmap; max->ops.set_current_limit = max8973_set_current_limit; max->ops.get_current_limit = max8973_get_current_limit; break; default: break; } ret = max8973_init_dcdc(max, pdata); if (ret < 0) { dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret); return ret; } config.dev = &client->dev; config.init_data = pdata->reg_init_data; config.driver_data = max; config.of_node = client->dev.of_node; config.regmap = max->regmap; /* Register the regulators */ rdev = devm_regulator_register(&client->dev, &max->desc, &config); if (IS_ERR(rdev)) { ret = PTR_ERR(rdev); dev_err(max->dev, "regulator register failed, err %d\n", ret); return ret; } return 0; } static const struct i2c_device_id max8973_id[] = { {.name = "max8973", .driver_data = MAX8973}, {.name = "max77621", .driver_data = MAX77621}, {}, }; MODULE_DEVICE_TABLE(i2c, max8973_id); static struct i2c_driver max8973_i2c_driver = { .driver = { .name = "max8973", .of_match_table = of_max8973_match_tbl, .owner = THIS_MODULE, }, .probe = max8973_probe, .id_table = max8973_id, }; static int __init max8973_init(void) { return i2c_add_driver(&max8973_i2c_driver); } subsys_initcall(max8973_init); static void __exit max8973_cleanup(void) { i2c_del_driver(&max8973_i2c_driver); } module_exit(max8973_cleanup); MODULE_AUTHOR("Laxman Dewangan "); MODULE_DESCRIPTION("MAX8973 voltage regulator driver"); MODULE_LICENSE("GPL v2");