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