| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * max8660.c -- Voltage regulation for the Maxim 8660/8661 |
| * |
| * based on max1586.c and wm8400-regulator.c |
| * |
| * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K. |
| * |
| * Some info: |
| * |
| * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf |
| * |
| * This chip is a bit nasty because it is a write-only device. Thus, the driver |
| * uses shadow registers to keep track of its values. The main problem appears |
| * to be the initialization: When Linux boots up, we cannot know if the chip is |
| * in the default state or not, so we would have to pass such information in |
| * platform_data. As this adds a bit of complexity to the driver, this is left |
| * out for now until it is really needed. |
| * |
| * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2. |
| * |
| * If the driver is feature complete, it might be worth to check if one set of |
| * functions for V3-V7 is sufficient. For maximum flexibility during |
| * development, they are separated for now. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/err.h> |
| #include <linux/i2c.h> |
| #include <linux/platform_device.h> |
| #include <linux/regulator/driver.h> |
| #include <linux/slab.h> |
| #include <linux/regulator/max8660.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/regulator/of_regulator.h> |
| |
| #define MAX8660_DCDC_MIN_UV 725000 |
| #define MAX8660_DCDC_MAX_UV 1800000 |
| #define MAX8660_DCDC_STEP 25000 |
| #define MAX8660_DCDC_MAX_SEL 0x2b |
| |
| #define MAX8660_LDO5_MIN_UV 1700000 |
| #define MAX8660_LDO5_MAX_UV 2000000 |
| #define MAX8660_LDO5_STEP 25000 |
| #define MAX8660_LDO5_MAX_SEL 0x0c |
| |
| #define MAX8660_LDO67_MIN_UV 1800000 |
| #define MAX8660_LDO67_MAX_UV 3300000 |
| #define MAX8660_LDO67_STEP 100000 |
| #define MAX8660_LDO67_MAX_SEL 0x0f |
| |
| enum { |
| MAX8660_OVER1, |
| MAX8660_OVER2, |
| MAX8660_VCC1, |
| MAX8660_ADTV1, |
| MAX8660_ADTV2, |
| MAX8660_SDTV1, |
| MAX8660_SDTV2, |
| MAX8660_MDTV1, |
| MAX8660_MDTV2, |
| MAX8660_L12VCR, |
| MAX8660_FPWM, |
| MAX8660_N_REGS, /* not a real register */ |
| }; |
| |
| struct max8660 { |
| struct i2c_client *client; |
| u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ |
| }; |
| |
| static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) |
| { |
| static const u8 max8660_addresses[MAX8660_N_REGS] = { |
| 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 |
| }; |
| |
| int ret; |
| u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; |
| |
| dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n", |
| max8660_addresses[reg], reg_val); |
| |
| ret = i2c_smbus_write_byte_data(max8660->client, |
| max8660_addresses[reg], reg_val); |
| if (ret == 0) |
| max8660->shadow_regs[reg] = reg_val; |
| |
| return ret; |
| } |
| |
| |
| /* |
| * DCDC functions |
| */ |
| |
| static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 val = max8660->shadow_regs[MAX8660_OVER1]; |
| u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; |
| |
| return !!(val & mask); |
| } |
| |
| static int max8660_dcdc_enable(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; |
| |
| return max8660_write(max8660, MAX8660_OVER1, 0xff, bit); |
| } |
| |
| static int max8660_dcdc_disable(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; |
| |
| return max8660_write(max8660, MAX8660_OVER1, mask, 0); |
| } |
| |
| static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; |
| u8 selector = max8660->shadow_regs[reg]; |
| |
| return selector; |
| } |
| |
| static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev, |
| unsigned int selector) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 reg, bits; |
| int ret; |
| |
| reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; |
| ret = max8660_write(max8660, reg, 0, selector); |
| if (ret) |
| return ret; |
| |
| /* Select target voltage register and activate regulation */ |
| bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; |
| return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); |
| } |
| |
| static struct regulator_ops max8660_dcdc_ops = { |
| .is_enabled = max8660_dcdc_is_enabled, |
| .list_voltage = regulator_list_voltage_linear, |
| .map_voltage = regulator_map_voltage_linear, |
| .set_voltage_sel = max8660_dcdc_set_voltage_sel, |
| .get_voltage_sel = max8660_dcdc_get_voltage_sel, |
| }; |
| |
| |
| /* |
| * LDO5 functions |
| */ |
| |
| static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| |
| u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; |
| return selector; |
| } |
| |
| static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev, |
| unsigned int selector) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| int ret; |
| |
| ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); |
| if (ret) |
| return ret; |
| |
| /* Select target voltage register and activate regulation */ |
| return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); |
| } |
| |
| static const struct regulator_ops max8660_ldo5_ops = { |
| .list_voltage = regulator_list_voltage_linear, |
| .map_voltage = regulator_map_voltage_linear, |
| .set_voltage_sel = max8660_ldo5_set_voltage_sel, |
| .get_voltage_sel = max8660_ldo5_get_voltage_sel, |
| }; |
| |
| |
| /* |
| * LDO67 functions |
| */ |
| |
| static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 val = max8660->shadow_regs[MAX8660_OVER2]; |
| u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; |
| |
| return !!(val & mask); |
| } |
| |
| static int max8660_ldo67_enable(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; |
| |
| return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); |
| } |
| |
| static int max8660_ldo67_disable(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; |
| |
| return max8660_write(max8660, MAX8660_OVER2, mask, 0); |
| } |
| |
| static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; |
| u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; |
| |
| return selector; |
| } |
| |
| static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev, |
| unsigned int selector) |
| { |
| struct max8660 *max8660 = rdev_get_drvdata(rdev); |
| |
| if (rdev_get_id(rdev) == MAX8660_V6) |
| return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); |
| else |
| return max8660_write(max8660, MAX8660_L12VCR, 0x0f, |
| selector << 4); |
| } |
| |
| static const struct regulator_ops max8660_ldo67_ops = { |
| .is_enabled = max8660_ldo67_is_enabled, |
| .enable = max8660_ldo67_enable, |
| .disable = max8660_ldo67_disable, |
| .list_voltage = regulator_list_voltage_linear, |
| .map_voltage = regulator_map_voltage_linear, |
| .get_voltage_sel = max8660_ldo67_get_voltage_sel, |
| .set_voltage_sel = max8660_ldo67_set_voltage_sel, |
| }; |
| |
| static const struct regulator_desc max8660_reg[] = { |
| { |
| .name = "V3(DCDC)", |
| .id = MAX8660_V3, |
| .ops = &max8660_dcdc_ops, |
| .type = REGULATOR_VOLTAGE, |
| .n_voltages = MAX8660_DCDC_MAX_SEL + 1, |
| .owner = THIS_MODULE, |
| .min_uV = MAX8660_DCDC_MIN_UV, |
| .uV_step = MAX8660_DCDC_STEP, |
| }, |
| { |
| .name = "V4(DCDC)", |
| .id = MAX8660_V4, |
| .ops = &max8660_dcdc_ops, |
| .type = REGULATOR_VOLTAGE, |
| .n_voltages = MAX8660_DCDC_MAX_SEL + 1, |
| .owner = THIS_MODULE, |
| .min_uV = MAX8660_DCDC_MIN_UV, |
| .uV_step = MAX8660_DCDC_STEP, |
| }, |
| { |
| .name = "V5(LDO)", |
| .id = MAX8660_V5, |
| .ops = &max8660_ldo5_ops, |
| .type = REGULATOR_VOLTAGE, |
| .n_voltages = MAX8660_LDO5_MAX_SEL + 1, |
| .owner = THIS_MODULE, |
| .min_uV = MAX8660_LDO5_MIN_UV, |
| .uV_step = MAX8660_LDO5_STEP, |
| }, |
| { |
| .name = "V6(LDO)", |
| .id = MAX8660_V6, |
| .ops = &max8660_ldo67_ops, |
| .type = REGULATOR_VOLTAGE, |
| .n_voltages = MAX8660_LDO67_MAX_SEL + 1, |
| .owner = THIS_MODULE, |
| .min_uV = MAX8660_LDO67_MIN_UV, |
| .uV_step = MAX8660_LDO67_STEP, |
| }, |
| { |
| .name = "V7(LDO)", |
| .id = MAX8660_V7, |
| .ops = &max8660_ldo67_ops, |
| .type = REGULATOR_VOLTAGE, |
| .n_voltages = MAX8660_LDO67_MAX_SEL + 1, |
| .owner = THIS_MODULE, |
| .min_uV = MAX8660_LDO67_MIN_UV, |
| .uV_step = MAX8660_LDO67_STEP, |
| }, |
| }; |
| |
| enum { |
| MAX8660 = 0, |
| MAX8661 = 1, |
| }; |
| |
| #ifdef CONFIG_OF |
| static const struct of_device_id max8660_dt_ids[] = { |
| { .compatible = "maxim,max8660", .data = (void *) MAX8660 }, |
| { .compatible = "maxim,max8661", .data = (void *) MAX8661 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, max8660_dt_ids); |
| |
| static int max8660_pdata_from_dt(struct device *dev, |
| struct device_node **of_node, |
| struct max8660_platform_data *pdata) |
| { |
| int matched, i; |
| struct device_node *np; |
| struct max8660_subdev_data *sub; |
| struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { }; |
| |
| np = of_get_child_by_name(dev->of_node, "regulators"); |
| if (!np) { |
| dev_err(dev, "missing 'regulators' subnode in DT\n"); |
| return -EINVAL; |
| } |
| |
| for (i = 0; i < ARRAY_SIZE(rmatch); i++) |
| rmatch[i].name = max8660_reg[i].name; |
| |
| matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch)); |
| of_node_put(np); |
| if (matched <= 0) |
| return matched; |
| |
| pdata->subdevs = devm_kcalloc(dev, |
| matched, |
| sizeof(struct max8660_subdev_data), |
| GFP_KERNEL); |
| if (!pdata->subdevs) |
| return -ENOMEM; |
| |
| pdata->num_subdevs = matched; |
| sub = pdata->subdevs; |
| |
| for (i = 0; i < matched; i++) { |
| sub->id = i; |
| sub->name = rmatch[i].name; |
| sub->platform_data = rmatch[i].init_data; |
| of_node[i] = rmatch[i].of_node; |
| sub++; |
| } |
| |
| return 0; |
| } |
| #else |
| static inline int max8660_pdata_from_dt(struct device *dev, |
| struct device_node **of_node, |
| struct max8660_platform_data *pdata) |
| { |
| return 0; |
| } |
| #endif |
| |
| static int max8660_probe(struct i2c_client *client) |
| { |
| const struct i2c_device_id *i2c_id = i2c_client_get_device_id(client); |
| struct device *dev = &client->dev; |
| struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev); |
| struct regulator_config config = { }; |
| struct max8660 *max8660; |
| int boot_on, i, id, ret = -EINVAL; |
| struct device_node *of_node[MAX8660_V_END]; |
| unsigned long type; |
| |
| if (dev->of_node && !pdata) { |
| const struct of_device_id *id; |
| |
| id = of_match_device(of_match_ptr(max8660_dt_ids), dev); |
| if (!id) |
| return -ENODEV; |
| |
| ret = max8660_pdata_from_dt(dev, of_node, &pdata_of); |
| if (ret < 0) |
| return ret; |
| |
| pdata = &pdata_of; |
| type = (unsigned long) id->data; |
| } else { |
| type = i2c_id->driver_data; |
| memset(of_node, 0, sizeof(of_node)); |
| } |
| |
| if (pdata->num_subdevs > MAX8660_V_END) { |
| dev_err(dev, "Too many regulators found!\n"); |
| return -EINVAL; |
| } |
| |
| max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL); |
| if (!max8660) |
| return -ENOMEM; |
| |
| max8660->client = client; |
| |
| if (pdata->en34_is_high) { |
| /* Simulate always on */ |
| max8660->shadow_regs[MAX8660_OVER1] = 5; |
| } else { |
| /* Otherwise devices can be toggled via software */ |
| max8660_dcdc_ops.enable = max8660_dcdc_enable; |
| max8660_dcdc_ops.disable = max8660_dcdc_disable; |
| } |
| |
| /* |
| * First, set up shadow registers to prevent glitches. As some |
| * registers are shared between regulators, everything must be properly |
| * set up for all regulators in advance. |
| */ |
| max8660->shadow_regs[MAX8660_ADTV1] = |
| max8660->shadow_regs[MAX8660_ADTV2] = |
| max8660->shadow_regs[MAX8660_SDTV1] = |
| max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; |
| max8660->shadow_regs[MAX8660_MDTV1] = |
| max8660->shadow_regs[MAX8660_MDTV2] = 0x04; |
| |
| for (i = 0; i < pdata->num_subdevs; i++) { |
| |
| if (!pdata->subdevs[i].platform_data) |
| boot_on = false; |
| else |
| boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; |
| |
| switch (pdata->subdevs[i].id) { |
| case MAX8660_V3: |
| if (boot_on) |
| max8660->shadow_regs[MAX8660_OVER1] |= 1; |
| break; |
| |
| case MAX8660_V4: |
| if (boot_on) |
| max8660->shadow_regs[MAX8660_OVER1] |= 4; |
| break; |
| |
| case MAX8660_V5: |
| break; |
| |
| case MAX8660_V6: |
| if (boot_on) |
| max8660->shadow_regs[MAX8660_OVER2] |= 2; |
| break; |
| |
| case MAX8660_V7: |
| if (type == MAX8661) { |
| dev_err(dev, "Regulator not on this chip!\n"); |
| return -EINVAL; |
| } |
| |
| if (boot_on) |
| max8660->shadow_regs[MAX8660_OVER2] |= 4; |
| break; |
| |
| default: |
| dev_err(dev, "invalid regulator %s\n", |
| pdata->subdevs[i].name); |
| return ret; |
| } |
| } |
| |
| /* Finally register devices */ |
| for (i = 0; i < pdata->num_subdevs; i++) { |
| struct regulator_dev *rdev; |
| |
| id = pdata->subdevs[i].id; |
| |
| config.dev = dev; |
| config.init_data = pdata->subdevs[i].platform_data; |
| config.of_node = of_node[i]; |
| config.driver_data = max8660; |
| |
| rdev = devm_regulator_register(&client->dev, |
| &max8660_reg[id], &config); |
| if (IS_ERR(rdev)) { |
| dev_err(&client->dev, "failed to register %s\n", |
| max8660_reg[id].name); |
| return PTR_ERR(rdev); |
| } |
| } |
| |
| i2c_set_clientdata(client, max8660); |
| return 0; |
| } |
| |
| static const struct i2c_device_id max8660_id[] = { |
| { .name = "max8660", .driver_data = MAX8660 }, |
| { .name = "max8661", .driver_data = MAX8661 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, max8660_id); |
| |
| static struct i2c_driver max8660_driver = { |
| .probe_new = max8660_probe, |
| .driver = { |
| .name = "max8660", |
| }, |
| .id_table = max8660_id, |
| }; |
| |
| static int __init max8660_init(void) |
| { |
| return i2c_add_driver(&max8660_driver); |
| } |
| subsys_initcall(max8660_init); |
| |
| static void __exit max8660_exit(void) |
| { |
| i2c_del_driver(&max8660_driver); |
| } |
| module_exit(max8660_exit); |
| |
| /* Module information */ |
| MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); |
| MODULE_AUTHOR("Wolfram Sang"); |
| MODULE_LICENSE("GPL v2"); |