/* * Regulators driver for Maxim max8649 * * Copyright (C) 2009-2010 Marvell International Ltd. * Haojian Zhuang <haojian.zhuang@marvell.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/kernel.h> #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/max8649.h> #define MAX8649_DCDC_VMIN 750000 /* uV */ #define MAX8649_DCDC_VMAX 1380000 /* uV */ #define MAX8649_DCDC_STEP 10000 /* uV */ #define MAX8649_VOL_MASK 0x3f /* Registers */ #define MAX8649_MODE0 0x00 #define MAX8649_MODE1 0x01 #define MAX8649_MODE2 0x02 #define MAX8649_MODE3 0x03 #define MAX8649_CONTROL 0x04 #define MAX8649_SYNC 0x05 #define MAX8649_RAMP 0x06 #define MAX8649_CHIP_ID1 0x08 #define MAX8649_CHIP_ID2 0x09 /* Bits */ #define MAX8649_EN_PD (1 << 7) #define MAX8649_VID0_PD (1 << 6) #define MAX8649_VID1_PD (1 << 5) #define MAX8649_VID_MASK (3 << 5) #define MAX8649_FORCE_PWM (1 << 7) #define MAX8649_SYNC_EXTCLK (1 << 6) #define MAX8649_EXT_MASK (3 << 6) #define MAX8649_RAMP_MASK (7 << 5) #define MAX8649_RAMP_DOWN (1 << 1) struct max8649_regulator_info { struct regulator_dev *regulator; struct i2c_client *i2c; struct device *dev; struct mutex io_lock; int vol_reg; unsigned mode:2; /* bit[1:0] = VID1, VID0 */ unsigned extclk_freq:2; unsigned extclk:1; unsigned ramp_timing:3; unsigned ramp_down:1; }; /* I2C operations */ static inline int max8649_read_device(struct i2c_client *i2c, int reg, int bytes, void *dest) { unsigned char data; int ret; data = (unsigned char)reg; ret = i2c_master_send(i2c, &data, 1); if (ret < 0) return ret; ret = i2c_master_recv(i2c, dest, bytes); if (ret < 0) return ret; return 0; } static inline int max8649_write_device(struct i2c_client *i2c, int reg, int bytes, void *src) { unsigned char buf[bytes + 1]; int ret; buf[0] = (unsigned char)reg; memcpy(&buf[1], src, bytes); ret = i2c_master_send(i2c, buf, bytes + 1); if (ret < 0) return ret; return 0; } static int max8649_reg_read(struct i2c_client *i2c, int reg) { struct max8649_regulator_info *info = i2c_get_clientdata(i2c); unsigned char data; int ret; mutex_lock(&info->io_lock); ret = max8649_read_device(i2c, reg, 1, &data); mutex_unlock(&info->io_lock); if (ret < 0) return ret; return (int)data; } static int max8649_set_bits(struct i2c_client *i2c, int reg, unsigned char mask, unsigned char data) { struct max8649_regulator_info *info = i2c_get_clientdata(i2c); unsigned char value; int ret; mutex_lock(&info->io_lock); ret = max8649_read_device(i2c, reg, 1, &value); if (ret < 0) goto out; value &= ~mask; value |= data; ret = max8649_write_device(i2c, reg, 1, &value); out: mutex_unlock(&info->io_lock); return ret; } static inline int check_range(int min_uV, int max_uV) { if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX) || (min_uV > max_uV)) return -EINVAL; return 0; } static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index) { return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP); } static int max8649_get_voltage(struct regulator_dev *rdev) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); unsigned char data; int ret; ret = max8649_reg_read(info->i2c, info->vol_reg); if (ret < 0) return ret; data = (unsigned char)ret & MAX8649_VOL_MASK; return max8649_list_voltage(rdev, data); } static int max8649_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); unsigned char data, mask; if (check_range(min_uV, max_uV)) { dev_err(info->dev, "invalid voltage range (%d, %d) uV\n", min_uV, max_uV); return -EINVAL; } data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1) / MAX8649_DCDC_STEP; mask = MAX8649_VOL_MASK; return max8649_set_bits(info->i2c, info->vol_reg, mask, data); } /* EN_PD means pulldown on EN input */ static int max8649_enable(struct regulator_dev *rdev) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0); } /* * Applied internal pulldown resistor on EN input pin. * If pulldown EN pin outside, it would be better. */ static int max8649_disable(struct regulator_dev *rdev) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, MAX8649_EN_PD); } static int max8649_is_enabled(struct regulator_dev *rdev) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); int ret; ret = max8649_reg_read(info->i2c, MAX8649_CONTROL); if (ret < 0) return ret; return !((unsigned char)ret & MAX8649_EN_PD); } static int max8649_enable_time(struct regulator_dev *rdev) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); int voltage, rate, ret; /* get voltage */ ret = max8649_reg_read(info->i2c, info->vol_reg); if (ret < 0) return ret; ret &= MAX8649_VOL_MASK; voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */ /* get rate */ ret = max8649_reg_read(info->i2c, MAX8649_RAMP); if (ret < 0) return ret; ret = (ret & MAX8649_RAMP_MASK) >> 5; rate = (32 * 1000) >> ret; /* uV/uS */ return (voltage / rate); } static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); switch (mode) { case REGULATOR_MODE_FAST: max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM, MAX8649_FORCE_PWM); break; case REGULATOR_MODE_NORMAL: max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM, 0); break; default: return -EINVAL; } return 0; } static unsigned int max8649_get_mode(struct regulator_dev *rdev) { struct max8649_regulator_info *info = rdev_get_drvdata(rdev); int ret; ret = max8649_reg_read(info->i2c, info->vol_reg); if (ret & MAX8649_FORCE_PWM) return REGULATOR_MODE_FAST; return REGULATOR_MODE_NORMAL; } static struct regulator_ops max8649_dcdc_ops = { .set_voltage = max8649_set_voltage, .get_voltage = max8649_get_voltage, .list_voltage = max8649_list_voltage, .enable = max8649_enable, .disable = max8649_disable, .is_enabled = max8649_is_enabled, .enable_time = max8649_enable_time, .set_mode = max8649_set_mode, .get_mode = max8649_get_mode, }; static struct regulator_desc dcdc_desc = { .name = "max8649", .ops = &max8649_dcdc_ops, .type = REGULATOR_VOLTAGE, .n_voltages = 1 << 6, .owner = THIS_MODULE, }; static int __devinit max8649_regulator_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct max8649_platform_data *pdata = client->dev.platform_data; struct max8649_regulator_info *info = NULL; unsigned char data; int ret; info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL); if (!info) { dev_err(&client->dev, "No enough memory\n"); return -ENOMEM; } info->i2c = client; info->dev = &client->dev; mutex_init(&info->io_lock); i2c_set_clientdata(client, info); info->mode = pdata->mode; switch (info->mode) { case 0: info->vol_reg = MAX8649_MODE0; break; case 1: info->vol_reg = MAX8649_MODE1; break; case 2: info->vol_reg = MAX8649_MODE2; break; case 3: info->vol_reg = MAX8649_MODE3; break; default: break; } ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1); if (ret < 0) { dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n", ret); goto out; } dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret); /* enable VID0 & VID1 */ max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0); /* enable/disable external clock synchronization */ info->extclk = pdata->extclk; data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0; max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data); if (info->extclk) { /* set external clock frequency */ info->extclk_freq = pdata->extclk_freq; max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK, info->extclk_freq << 6); } if (pdata->ramp_timing) { info->ramp_timing = pdata->ramp_timing; max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK, info->ramp_timing << 5); } info->ramp_down = pdata->ramp_down; if (info->ramp_down) { max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN, MAX8649_RAMP_DOWN); } info->regulator = regulator_register(&dcdc_desc, &client->dev, pdata->regulator, info); if (IS_ERR(info->regulator)) { dev_err(info->dev, "failed to register regulator %s\n", dcdc_desc.name); ret = PTR_ERR(info->regulator); goto out; } dev_info(info->dev, "Max8649 regulator device is detected.\n"); return 0; out: kfree(info); return ret; } static int __devexit max8649_regulator_remove(struct i2c_client *client) { struct max8649_regulator_info *info = i2c_get_clientdata(client); if (info) { if (info->regulator) regulator_unregister(info->regulator); kfree(info); } return 0; } static const struct i2c_device_id max8649_id[] = { { "max8649", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, max8649_id); static struct i2c_driver max8649_driver = { .probe = max8649_regulator_probe, .remove = __devexit_p(max8649_regulator_remove), .driver = { .name = "max8649", }, .id_table = max8649_id, }; static int __init max8649_init(void) { return i2c_add_driver(&max8649_driver); } subsys_initcall(max8649_init); static void __exit max8649_exit(void) { i2c_del_driver(&max8649_driver); } module_exit(max8649_exit); /* Module information */ MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver"); MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); MODULE_LICENSE("GPL");