linux-hardened/drivers/regulator/mt6311-regulator.c
Daniel Kurtz 47769cbc09 regulator: mt6311: Use REGCACHE_RBTREE
This regulator is on a slow i2c bus.  Register accesses are very simple,
they all either enable/disable a regulator channel, or select a new
voltage level.  Thus, reading registers from the device will always
return what was last written.

Therefore we can save a lot of time when reading registers by using a
regmap_cache.  Since the register map is relatively large, but we only
ever access a few of them, we use an RBTREE cache.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Henry Chen <henryc.chen@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-18 12:14:27 +00:00

180 lines
4.7 KiB
C

/*
* Copyright (c) 2015 MediaTek Inc.
* Author: Henry Chen <henryc.chen@mediatek.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.
*
* 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.
*/
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/mt6311.h>
#include <linux/slab.h>
#include "mt6311-regulator.h"
static const struct regmap_config mt6311_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = MT6311_FQMTR_CON4,
.cache_type = REGCACHE_RBTREE,
};
/* Default limits measured in millivolts and milliamps */
#define MT6311_MIN_UV 600000
#define MT6311_MAX_UV 1393750
#define MT6311_STEP_UV 6250
static const struct regulator_linear_range buck_volt_range[] = {
REGULATOR_LINEAR_RANGE(MT6311_MIN_UV, 0, 0x7f, MT6311_STEP_UV),
};
static const struct regulator_ops mt6311_buck_ops = {
.list_voltage = regulator_list_voltage_linear_range,
.map_voltage = regulator_map_voltage_linear_range,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
.set_voltage_time_sel = regulator_set_voltage_time_sel,
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.is_enabled = regulator_is_enabled_regmap,
};
static const struct regulator_ops mt6311_ldo_ops = {
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.is_enabled = regulator_is_enabled_regmap,
};
#define MT6311_BUCK(_id) \
{\
.name = #_id,\
.ops = &mt6311_buck_ops,\
.of_match = of_match_ptr(#_id),\
.regulators_node = of_match_ptr("regulators"),\
.type = REGULATOR_VOLTAGE,\
.id = MT6311_ID_##_id,\
.n_voltages = (MT6311_MAX_UV - MT6311_MIN_UV) / MT6311_STEP_UV + 1,\
.min_uV = MT6311_MIN_UV,\
.uV_step = MT6311_STEP_UV,\
.owner = THIS_MODULE,\
.linear_ranges = buck_volt_range, \
.n_linear_ranges = ARRAY_SIZE(buck_volt_range), \
.enable_reg = MT6311_VDVFS11_CON9,\
.enable_mask = MT6311_PMIC_VDVFS11_EN_MASK,\
.vsel_reg = MT6311_VDVFS11_CON12,\
.vsel_mask = MT6311_PMIC_VDVFS11_VOSEL_MASK,\
}
#define MT6311_LDO(_id) \
{\
.name = #_id,\
.ops = &mt6311_ldo_ops,\
.of_match = of_match_ptr(#_id),\
.regulators_node = of_match_ptr("regulators"),\
.type = REGULATOR_VOLTAGE,\
.id = MT6311_ID_##_id,\
.owner = THIS_MODULE,\
.enable_reg = MT6311_LDO_CON3,\
.enable_mask = MT6311_PMIC_RG_VBIASN_EN_MASK,\
}
static const struct regulator_desc mt6311_regulators[] = {
MT6311_BUCK(VDVFS),
MT6311_LDO(VBIASN),
};
/*
* I2C driver interface functions
*/
static int mt6311_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
struct regulator_config config = { };
struct regulator_dev *rdev;
struct regmap *regmap;
int i, ret;
unsigned int data;
regmap = devm_regmap_init_i2c(i2c, &mt6311_regmap_config);
if (IS_ERR(regmap)) {
ret = PTR_ERR(regmap);
dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
ret);
return ret;
}
ret = regmap_read(regmap, MT6311_SWCID, &data);
if (ret < 0) {
dev_err(&i2c->dev, "Failed to read DEVICE_ID reg: %d\n", ret);
return ret;
}
switch (data) {
case MT6311_E1_CID_CODE:
case MT6311_E2_CID_CODE:
case MT6311_E3_CID_CODE:
break;
default:
dev_err(&i2c->dev, "Unsupported device id = 0x%x.\n", data);
return -ENODEV;
}
for (i = 0; i < MT6311_MAX_REGULATORS; i++) {
config.dev = &i2c->dev;
config.regmap = regmap;
rdev = devm_regulator_register(&i2c->dev,
&mt6311_regulators[i], &config);
if (IS_ERR(rdev)) {
dev_err(&i2c->dev,
"Failed to register MT6311 regulator\n");
return PTR_ERR(rdev);
}
}
return 0;
}
static const struct i2c_device_id mt6311_i2c_id[] = {
{"mt6311", 0},
{},
};
MODULE_DEVICE_TABLE(i2c, mt6311_i2c_id);
#ifdef CONFIG_OF
static const struct of_device_id mt6311_dt_ids[] = {
{ .compatible = "mediatek,mt6311-regulator",
.data = &mt6311_i2c_id[0] },
{},
};
MODULE_DEVICE_TABLE(of, mt6311_dt_ids);
#endif
static struct i2c_driver mt6311_regulator_driver = {
.driver = {
.name = "mt6311",
.of_match_table = of_match_ptr(mt6311_dt_ids),
},
.probe = mt6311_i2c_probe,
.id_table = mt6311_i2c_id,
};
module_i2c_driver(mt6311_regulator_driver);
MODULE_AUTHOR("Henry Chen <henryc.chen@mediatek.com>");
MODULE_DESCRIPTION("Regulator device driver for Mediatek MT6311");
MODULE_LICENSE("GPL v2");