diff options
Diffstat (limited to 'drivers/regulator/max8952.c')
| -rw-r--r-- | drivers/regulator/max8952.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/drivers/regulator/max8952.c b/drivers/regulator/max8952.c new file mode 100644 index 000000000000..bc0c8b8835c5 --- /dev/null +++ b/drivers/regulator/max8952.c @@ -0,0 +1,313 @@ +/* + * max8952.c -- support regulators in max8952 + * + * Copyright (C) 2010 Gyungoh Yoo <jack.yoo@maxim-ic.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/regulator/driver.h> +#include <linux/slab.h> +#include <linux/regulator/max8952.h> +#include <linux/platform_device.h> + +#define VOLTAGE_TO_VALUE(v) (((v) - 750000) / 10000) +#define VALUE_TO_VOLTAGE(val) ((val) * 10000 + 750000) + +struct max8952_info { + int voltages_count; + const int *voltages_list; + u8 reg_base; + struct regulator_desc desc; +}; + +#define REG(ids, base, list) \ + { \ + .voltages_list = (list), \ + .reg_base = (base), \ + .desc = { \ + .name = #ids, \ + .id = MAX8952_##ids, \ + .n_voltages = ARRAY_SIZE((list)), \ + .ops = &max8952_ops, \ + .type = REGULATOR_VOLTAGE, \ + .owner = THIS_MODULE, \ + }, \ + } + +static const int max8952_mode0_voltages[] = { + 750000, 760000, 1260000, 1270000, 1280000, 1370000, 1380000 +}; + +static const int max8952_mode1_voltages[] = { + 750000, 760000, 1040000, 1050000, 1060000, 1370000, 1380000 +}; + +static const int max8952_mode2_voltages[] = { + 750000, 760000, 1210000, 1220000, 1230000, 1370000, 1380000 +}; + +static const int max8952_mode3_voltages[] = { + 750000, 760000, 1040000, 1050000, 1060000, 1370000, 1380000 +}; + +static int max8952_list_voltage(struct regulator_dev *dev, unsigned index); +static int max8952_set_voltage(struct regulator_dev *dev, int min_uV, + int max_uV); +static int max8952_get_voltage(struct regulator_dev *dev); + +static struct regulator_ops max8952_ops = { + .list_voltage = max8952_list_voltage, + .set_voltage = max8952_set_voltage, + .get_voltage = max8952_get_voltage, +}; + +static struct max8952_info max8952_regulators[] = { + REG(MODE0, MAX8952_REG_MODE0, max8952_mode0_voltages), + REG(MODE1, MAX8952_REG_MODE1, max8952_mode1_voltages), + REG(MODE2, MAX8952_REG_MODE2, max8952_mode2_voltages), + REG(MODE3, MAX8952_REG_MODE3, max8952_mode3_voltages), +}; + +#define MAX8952_REGULATOR_CNT (ARRAY_SIZE(max8952_regulators)) + +struct max8952 { + struct i2c_client *i2c; + struct mutex io_lock; + struct regulator_dev *rdev[MAX8952_REGULATOR_CNT]; +}; + +static int max8952_i2c_read(struct i2c_client *i2c, u8 reg, u8 count, u8 * dest) +{ + struct i2c_msg xfer[2]; + int ret; + + xfer[0].addr = i2c->addr; + xfer[0].flags = I2C_M_NOSTART; + xfer[0].len = 1; + xfer[0].buf = ® + + xfer[1].addr = i2c->addr; + xfer[1].flags = I2C_M_RD; + xfer[1].len = count; + xfer[1].buf = dest; + + ret = i2c_transfer(i2c->adapter, xfer, 2); + if (ret == 2) + ret = 0; + else if (ret >= 0) + ret = -EIO; + + return ret; +} + +static int max8952_i2c_write(struct i2c_client *i2c, u8 reg, u8 count, + const u8 *src) +{ + u8 msg[0x100 + 1]; + int ret; + + msg[0] = reg; + memcpy(&msg[1], src, count); + + ret = i2c_master_send(i2c, msg, count + 1); + if (ret < 0) + return ret; + if (ret != count + 1) + return -EIO; + return 0; +} + +static u8 max8952_read(struct max8952 *max8952, u8 reg) +{ + u8 val; + int ret; + + mutex_lock(&max8952->io_lock); + + ret = max8952_i2c_read(max8952->i2c, reg, 1, &val); + + mutex_unlock(&max8952->io_lock); + pr_debug("max8952: reg read reg=%x, val=%x\n", (unsigned int)reg, + (unsigned int)val); + + if (ret < 0) + pr_err("Failed to read max8952 I2C driver: %d\n", ret); + return val; +} + +static int max8952_write(struct max8952 *max8952, u8 reg, u8 val) +{ + int ret; + + pr_debug("max8952: reg write reg=%x, val=%x\n", (unsigned int)reg, + (unsigned int)val); + mutex_lock(&max8952->io_lock); + + ret = max8952_i2c_write(max8952->i2c, reg, 1, &val); + + mutex_unlock(&max8952->io_lock); + + if (ret < 0) + pr_err("Failed to write max8952 I2C driver: %d\n", ret); + return ret; +} + +int max8952_set_bits(struct max8952 *max8952, u8 reg, u8 mask, u8 val) +{ + u8 tmp; + int ret; + + pr_debug("max8952: reg write reg=%02X, val=%02X, mask=%02X\n", + (unsigned int)reg, (unsigned int)val, (unsigned int)mask); + mutex_lock(&max8952->io_lock); + + ret = max8952_i2c_read(max8952->i2c, reg, 1, &tmp); + if (ret == 0) { + val = (tmp & ~mask) | (val & mask); + ret = max8952_i2c_write(max8952->i2c, reg, 1, &val); + } + + mutex_unlock(&max8952->io_lock); + + if (ret != 0) + pr_err("Failed to write max8952 I2C driver: %d\n", ret); + return ret; +} + +static int max8952_list_voltage(struct regulator_dev *rdev, unsigned index) +{ + const struct max8952_info *reg = &max8952_regulators[rdev_get_id(rdev)]; + + return reg->voltages_list[index]; +} + +static int max8952_set_voltage(struct regulator_dev *rdev, int min_uV, + int max_uV) +{ + struct max8952 *max8952 = rdev_get_drvdata(rdev); + const struct max8952_info *reg = &max8952_regulators[rdev_get_id(rdev)]; + int val = -1; + int voltage; + int i; + + for (i = 0; i < reg->desc.n_voltages; i++) { + voltage = reg->voltages_list[i]; + if (min_uV <= voltage && voltage <= max_uV) { + val = VOLTAGE_TO_VALUE(voltage); + break; + } + } + if (val == -1) + return -EDOM; + + return max8952_set_bits(max8952, reg->reg_base, MAX8952_MASK_OUTMODE, + val); +} + +static int max8952_get_voltage(struct regulator_dev *rdev) +{ + struct max8952 *max8952 = rdev_get_drvdata(rdev); + const struct max8952_info *reg = &max8952_regulators[rdev_get_id(rdev)]; + int val; + + val = max8952_read(max8952, reg->reg_base); + val &= MAX8952_MASK_OUTMODE; + + return VALUE_TO_VOLTAGE(val); +} + +static int __devinit max8952_probe(struct i2c_client *i2c, + const struct i2c_device_id *i2c_id) +{ + struct max8952 *max8952; + struct max8952_platform_data *pdata = i2c->dev.platform_data; + struct regulator_dev *rdev; + int id; + int i; + + max8952 = kzalloc(sizeof(struct max8952), GFP_KERNEL); + if (max8952 == NULL) + return -ENOMEM; + + max8952->i2c = i2c; + mutex_init(&max8952->io_lock); + + for (i = 0; i < pdata->num_subdevs; i++) { + id = pdata->subdevs[i]->id; + rdev = + regulator_register(&max8952_regulators[id].desc, &i2c->dev, + (struct regulator_init_data *)pdata-> + subdevs[i]->dev.platform_data, max8952); + if (IS_ERR(rdev)) { + dev_err(&i2c->dev, + "Cannot register regulator \"%s\", %ld\n", + max8952_regulators[id].desc.name, + PTR_ERR(rdev)); + goto error; + } + max8952->rdev[id] = rdev; + } + + i2c_set_clientdata(i2c, max8952); + return 0; + +error: + kfree(max8952); + return PTR_ERR(rdev); +} + +static int __devexit max8952_remove(struct i2c_client *i2c) +{ + struct max8952 *max8952 = i2c_get_clientdata(i2c); + int i; + + for (i = 0; i < MAX8952_REGULATOR_CNT; i++) { + if (max8952->rdev[i]) + regulator_unregister(max8952->rdev[i]); + } + kfree(max8952); + + return 0; +} + +static const struct i2c_device_id max8952_id[] = { + {"max8952", 0}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, max8952_id); + +static struct i2c_driver max8952_driver = { + .probe = max8952_probe, + .remove = __devexit_p(max8952_remove), + .driver = { + .name = "max8952", + .owner = THIS_MODULE, + }, + .id_table = max8952_id, +}; + +static int __init max8952_init(void) +{ + return i2c_add_driver(&max8952_driver); +} + +subsys_initcall(max8952_init); + +static void __exit max8952_exit(void) +{ + i2c_del_driver(&max8952_driver); +} + +module_exit(max8952_exit); + +MODULE_DESCRIPTION("MAX8952 regulator driver"); +MODULE_AUTHOR("Gyungoh Yoo <jack.yoo@maxim-ic.com>"); +MODULE_LICENSE("GPL"); |