linux/drivers/regulator/max14577-regulator.c
Douglas Anderson 259b93b21a
regulator: Set PROBE_PREFER_ASYNCHRONOUS for drivers that existed in 4.14
Probing of regulators can be a slow operation and can contribute to
slower boot times. This is especially true if a regulator is turned on
at probe time (with regulator-boot-on or regulator-always-on) and the
regulator requires delays (off-on-time, ramp time, etc).

While the overall kernel is not ready to switch to async probe by
default, as per the discussion on the mailing lists [1] it is believed
that the regulator subsystem is in good shape and we can move
regulator drivers over wholesale. There is no way to just magically
opt in all regulators (regulators are just normal drivers like
platform_driver), so we set PROBE_PREFER_ASYNCHRONOUS for all
regulators found in 'drivers/regulator' individually.

Given the number of drivers touched and the impossibility to test this
ahead of time, it wouldn't be shocking at all if this caused a
regression for someone. If there is a regression caused by this patch,
it's likely to be one of the cases talked about in [1]. As a "quick
fix", drivers involved in the regression could be fixed by changing
them to PROBE_FORCE_SYNCHRONOUS. That being said, the correct fix
would be to directly fix the problem that caused the issue with async
probe.

The approach here follows a similar approach that was used for the mmc
subsystem several years ago [2]. In fact, I ran nearly the same python
script to auto-generate the changes. The only thing I changed was to
search for "i2c_driver", "spmi_driver", and "spi_driver" in addition
to "platform_driver".

[1] https://lore.kernel.org/r/06db017f-e985-4434-8d1d-02ca2100cca0@sirena.org.uk
[2] https://lore.kernel.org/r/20200903232441.2694866-1-dianders@chromium.org/

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230316125351.1.I2a4677392a38db5758dee0788b2cea5872562a82@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-03-20 13:11:25 +00:00

273 lines
8.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
//
// max14577.c - Regulator driver for the Maxim 14577/77836
//
// Copyright (C) 2013,2014 Samsung Electronics
// Krzysztof Kozlowski <krzk@kernel.org>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/mfd/max14577.h>
#include <linux/mfd/max14577-private.h>
#include <linux/regulator/of_regulator.h>
static int max14577_reg_is_enabled(struct regulator_dev *rdev)
{
int rid = rdev_get_id(rdev);
struct regmap *rmap = rdev->regmap;
u8 reg_data;
switch (rid) {
case MAX14577_CHARGER:
max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL2, &reg_data);
if ((reg_data & CHGCTRL2_MBCHOSTEN_MASK) == 0)
return 0;
max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
if ((reg_data & STATUS3_CGMBC_MASK) == 0)
return 0;
/* MBCHOSTEN and CGMBC are on */
return 1;
default:
return -EINVAL;
}
}
static int max14577_reg_get_current_limit(struct regulator_dev *rdev)
{
u8 reg_data;
struct regmap *rmap = rdev->regmap;
struct max14577 *max14577 = rdev_get_drvdata(rdev);
const struct maxim_charger_current *limits =
&maxim_charger_currents[max14577->dev_type];
if (rdev_get_id(rdev) != MAX14577_CHARGER)
return -EINVAL;
max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL4, &reg_data);
if ((reg_data & CHGCTRL4_MBCICHWRCL_MASK) == 0)
return limits->min;
reg_data = ((reg_data & CHGCTRL4_MBCICHWRCH_MASK) >>
CHGCTRL4_MBCICHWRCH_SHIFT);
return limits->high_start + reg_data * limits->high_step;
}
static int max14577_reg_set_current_limit(struct regulator_dev *rdev,
int min_uA, int max_uA)
{
u8 reg_data;
int ret;
struct max14577 *max14577 = rdev_get_drvdata(rdev);
const struct maxim_charger_current *limits =
&maxim_charger_currents[max14577->dev_type];
if (rdev_get_id(rdev) != MAX14577_CHARGER)
return -EINVAL;
ret = maxim_charger_calc_reg_current(limits, min_uA, max_uA, &reg_data);
if (ret)
return ret;
return max14577_update_reg(rdev->regmap, MAX14577_CHG_REG_CHG_CTRL4,
CHGCTRL4_MBCICHWRCL_MASK | CHGCTRL4_MBCICHWRCH_MASK,
reg_data);
}
static const struct regulator_ops max14577_safeout_ops = {
.is_enabled = regulator_is_enabled_regmap,
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.list_voltage = regulator_list_voltage_linear,
};
static const struct regulator_ops max14577_charger_ops = {
.is_enabled = max14577_reg_is_enabled,
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.get_current_limit = max14577_reg_get_current_limit,
.set_current_limit = max14577_reg_set_current_limit,
};
#define MAX14577_SAFEOUT_REG { \
.name = "SAFEOUT", \
.of_match = of_match_ptr("SAFEOUT"), \
.regulators_node = of_match_ptr("regulators"), \
.id = MAX14577_SAFEOUT, \
.ops = &max14577_safeout_ops, \
.type = REGULATOR_VOLTAGE, \
.owner = THIS_MODULE, \
.n_voltages = 1, \
.min_uV = MAX14577_REGULATOR_SAFEOUT_VOLTAGE, \
.enable_reg = MAX14577_REG_CONTROL2, \
.enable_mask = CTRL2_SFOUTORD_MASK, \
}
#define MAX14577_CHARGER_REG { \
.name = "CHARGER", \
.of_match = of_match_ptr("CHARGER"), \
.regulators_node = of_match_ptr("regulators"), \
.id = MAX14577_CHARGER, \
.ops = &max14577_charger_ops, \
.type = REGULATOR_CURRENT, \
.owner = THIS_MODULE, \
.enable_reg = MAX14577_CHG_REG_CHG_CTRL2, \
.enable_mask = CHGCTRL2_MBCHOSTEN_MASK, \
}
static const struct regulator_desc max14577_supported_regulators[] = {
[MAX14577_SAFEOUT] = MAX14577_SAFEOUT_REG,
[MAX14577_CHARGER] = MAX14577_CHARGER_REG,
};
static const struct regulator_ops max77836_ldo_ops = {
.is_enabled = regulator_is_enabled_regmap,
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.list_voltage = regulator_list_voltage_linear,
.map_voltage = regulator_map_voltage_linear,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
/* TODO: add .set_suspend_mode */
};
#define MAX77836_LDO_REG(num) { \
.name = "LDO" # num, \
.of_match = of_match_ptr("LDO" # num), \
.regulators_node = of_match_ptr("regulators"), \
.id = MAX77836_LDO ## num, \
.ops = &max77836_ldo_ops, \
.type = REGULATOR_VOLTAGE, \
.owner = THIS_MODULE, \
.n_voltages = MAX77836_REGULATOR_LDO_VOLTAGE_STEPS_NUM, \
.min_uV = MAX77836_REGULATOR_LDO_VOLTAGE_MIN, \
.uV_step = MAX77836_REGULATOR_LDO_VOLTAGE_STEP, \
.enable_reg = MAX77836_LDO_REG_CNFG1_LDO ## num, \
.enable_mask = MAX77836_CNFG1_LDO_PWRMD_MASK, \
.vsel_reg = MAX77836_LDO_REG_CNFG1_LDO ## num, \
.vsel_mask = MAX77836_CNFG1_LDO_TV_MASK, \
}
static const struct regulator_desc max77836_supported_regulators[] = {
[MAX14577_SAFEOUT] = MAX14577_SAFEOUT_REG,
[MAX14577_CHARGER] = MAX14577_CHARGER_REG,
[MAX77836_LDO1] = MAX77836_LDO_REG(1),
[MAX77836_LDO2] = MAX77836_LDO_REG(2),
};
/*
* Registers for regulators of max77836 use different I2C slave addresses so
* different regmaps must be used for them.
*
* Returns proper regmap for accessing regulator passed by id.
*/
static struct regmap *max14577_get_regmap(struct max14577 *max14577,
int reg_id)
{
switch (max14577->dev_type) {
case MAXIM_DEVICE_TYPE_MAX77836:
switch (reg_id) {
case MAX77836_SAFEOUT ... MAX77836_CHARGER:
return max14577->regmap;
default:
/* MAX77836_LDO1 ... MAX77836_LDO2 */
return max14577->regmap_pmic;
}
case MAXIM_DEVICE_TYPE_MAX14577:
default:
return max14577->regmap;
}
}
static int max14577_regulator_probe(struct platform_device *pdev)
{
struct max14577 *max14577 = dev_get_drvdata(pdev->dev.parent);
struct max14577_platform_data *pdata = dev_get_platdata(max14577->dev);
int i, ret = 0;
struct regulator_config config = {};
const struct regulator_desc *supported_regulators;
unsigned int supported_regulators_size;
enum maxim_device_type dev_type = max14577->dev_type;
switch (dev_type) {
case MAXIM_DEVICE_TYPE_MAX77836:
supported_regulators = max77836_supported_regulators;
supported_regulators_size = ARRAY_SIZE(max77836_supported_regulators);
break;
case MAXIM_DEVICE_TYPE_MAX14577:
default:
supported_regulators = max14577_supported_regulators;
supported_regulators_size = ARRAY_SIZE(max14577_supported_regulators);
}
config.dev = max14577->dev;
config.driver_data = max14577;
for (i = 0; i < supported_regulators_size; i++) {
struct regulator_dev *regulator;
/*
* Index of supported_regulators[] is also the id and must
* match index of pdata->regulators[].
*/
if (pdata && pdata->regulators) {
config.init_data = pdata->regulators[i].initdata;
config.of_node = pdata->regulators[i].of_node;
}
config.regmap = max14577_get_regmap(max14577,
supported_regulators[i].id);
regulator = devm_regulator_register(&pdev->dev,
&supported_regulators[i], &config);
if (IS_ERR(regulator)) {
ret = PTR_ERR(regulator);
dev_err(&pdev->dev,
"Regulator init failed for %d/%s with error: %d\n",
i, supported_regulators[i].name, ret);
return ret;
}
}
return ret;
}
static const struct platform_device_id max14577_regulator_id[] = {
{ "max14577-regulator", MAXIM_DEVICE_TYPE_MAX14577, },
{ "max77836-regulator", MAXIM_DEVICE_TYPE_MAX77836, },
{ }
};
MODULE_DEVICE_TABLE(platform, max14577_regulator_id);
static struct platform_driver max14577_regulator_driver = {
.driver = {
.name = "max14577-regulator",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
.probe = max14577_regulator_probe,
.id_table = max14577_regulator_id,
};
static int __init max14577_regulator_init(void)
{
BUILD_BUG_ON(ARRAY_SIZE(max14577_supported_regulators) != MAX14577_REGULATOR_NUM);
BUILD_BUG_ON(ARRAY_SIZE(max77836_supported_regulators) != MAX77836_REGULATOR_NUM);
BUILD_BUG_ON(MAX77836_REGULATOR_LDO_VOLTAGE_MIN +
(MAX77836_REGULATOR_LDO_VOLTAGE_STEP *
(MAX77836_REGULATOR_LDO_VOLTAGE_STEPS_NUM - 1)) !=
MAX77836_REGULATOR_LDO_VOLTAGE_MAX);
return platform_driver_register(&max14577_regulator_driver);
}
subsys_initcall(max14577_regulator_init);
static void __exit max14577_regulator_exit(void)
{
platform_driver_unregister(&max14577_regulator_driver);
}
module_exit(max14577_regulator_exit);
MODULE_AUTHOR("Krzysztof Kozlowski <krzk@kernel.org>");
MODULE_DESCRIPTION("Maxim 14577/77836 regulator driver");
MODULE_LICENSE("GPL");