diff options
Diffstat (limited to 'drivers/regulator/max8660.c')
| -rw-r--r-- | drivers/regulator/max8660.c | 542 |
1 files changed, 542 insertions, 0 deletions
diff --git a/drivers/regulator/max8660.c b/drivers/regulator/max8660.c new file mode 100644 index 000000000..4cf6897a4 --- /dev/null +++ b/drivers/regulator/max8660.c @@ -0,0 +1,542 @@ +/* + * 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. + * + * 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 of the License. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; 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 + * + * 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) +{ + 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)) { + ret = PTR_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 = 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"); |