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linux-next/drivers/regulator/max8925-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

287 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Regulators driver for Maxim max8925
*
* Copyright (C) 2009 Marvell International Ltd.
* Haojian Zhuang <haojian.zhuang@marvell.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/mfd/max8925.h>
#include <linux/of.h>
#include <linux/regulator/of_regulator.h>
#define SD1_DVM_VMIN 850000
#define SD1_DVM_VMAX 1000000
#define SD1_DVM_STEP 50000
#define SD1_DVM_SHIFT 5 /* SDCTL1 bit5 */
#define SD1_DVM_EN 6 /* SDV1 bit 6 */
/* bit definitions in LDO control registers */
#define LDO_SEQ_I2C 0x7 /* Power U/D by i2c */
#define LDO_SEQ_MASK 0x7 /* Power U/D sequence mask */
#define LDO_SEQ_SHIFT 2 /* Power U/D sequence offset */
#define LDO_I2C_EN 0x1 /* Enable by i2c */
#define LDO_I2C_EN_MASK 0x1 /* Enable mask by i2c */
#define LDO_I2C_EN_SHIFT 0 /* Enable offset by i2c */
struct max8925_regulator_info {
struct regulator_desc desc;
struct i2c_client *i2c;
int vol_reg;
int enable_reg;
};
static int max8925_set_voltage_sel(struct regulator_dev *rdev,
unsigned int selector)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
unsigned char mask = rdev->desc->n_voltages - 1;
return max8925_set_bits(info->i2c, info->vol_reg, mask, selector);
}
static int max8925_get_voltage_sel(struct regulator_dev *rdev)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
unsigned char data, mask;
int ret;
ret = max8925_reg_read(info->i2c, info->vol_reg);
if (ret < 0)
return ret;
mask = rdev->desc->n_voltages - 1;
data = ret & mask;
return data;
}
static int max8925_enable(struct regulator_dev *rdev)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
return max8925_set_bits(info->i2c, info->enable_reg,
LDO_SEQ_MASK << LDO_SEQ_SHIFT |
LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT,
LDO_SEQ_I2C << LDO_SEQ_SHIFT |
LDO_I2C_EN << LDO_I2C_EN_SHIFT);
}
static int max8925_disable(struct regulator_dev *rdev)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
return max8925_set_bits(info->i2c, info->enable_reg,
LDO_SEQ_MASK << LDO_SEQ_SHIFT |
LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT,
LDO_SEQ_I2C << LDO_SEQ_SHIFT);
}
static int max8925_is_enabled(struct regulator_dev *rdev)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
int ldo_seq, ret;
ret = max8925_reg_read(info->i2c, info->enable_reg);
if (ret < 0)
return ret;
ldo_seq = (ret >> LDO_SEQ_SHIFT) & LDO_SEQ_MASK;
if (ldo_seq != LDO_SEQ_I2C)
return 1;
else
return ret & (LDO_I2C_EN_MASK << LDO_I2C_EN_SHIFT);
}
static int max8925_set_dvm_voltage(struct regulator_dev *rdev, int uV)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
unsigned char data, mask;
if (uV < SD1_DVM_VMIN || uV > SD1_DVM_VMAX)
return -EINVAL;
data = DIV_ROUND_UP(uV - SD1_DVM_VMIN, SD1_DVM_STEP);
data <<= SD1_DVM_SHIFT;
mask = 3 << SD1_DVM_SHIFT;
return max8925_set_bits(info->i2c, info->enable_reg, mask, data);
}
static int max8925_set_dvm_enable(struct regulator_dev *rdev)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN,
1 << SD1_DVM_EN);
}
static int max8925_set_dvm_disable(struct regulator_dev *rdev)
{
struct max8925_regulator_info *info = rdev_get_drvdata(rdev);
return max8925_set_bits(info->i2c, info->vol_reg, 1 << SD1_DVM_EN, 0);
}
static const struct regulator_ops max8925_regulator_sdv_ops = {
.map_voltage = regulator_map_voltage_linear,
.list_voltage = regulator_list_voltage_linear,
.set_voltage_sel = max8925_set_voltage_sel,
.get_voltage_sel = max8925_get_voltage_sel,
.enable = max8925_enable,
.disable = max8925_disable,
.is_enabled = max8925_is_enabled,
.set_suspend_voltage = max8925_set_dvm_voltage,
.set_suspend_enable = max8925_set_dvm_enable,
.set_suspend_disable = max8925_set_dvm_disable,
};
static const struct regulator_ops max8925_regulator_ldo_ops = {
.map_voltage = regulator_map_voltage_linear,
.list_voltage = regulator_list_voltage_linear,
.set_voltage_sel = max8925_set_voltage_sel,
.get_voltage_sel = max8925_get_voltage_sel,
.enable = max8925_enable,
.disable = max8925_disable,
.is_enabled = max8925_is_enabled,
};
#define MAX8925_SDV(_id, min, max, step) \
{ \
.desc = { \
.name = "SDV" #_id, \
.of_match = of_match_ptr("SDV" #_id), \
.regulators_node = of_match_ptr("regulators"), \
.ops = &max8925_regulator_sdv_ops, \
.type = REGULATOR_VOLTAGE, \
.id = MAX8925_ID_SD##_id, \
.owner = THIS_MODULE, \
.n_voltages = 64, \
.min_uV = min * 1000, \
.uV_step = step * 1000, \
}, \
.vol_reg = MAX8925_SDV##_id, \
.enable_reg = MAX8925_SDCTL##_id, \
}
#define MAX8925_LDO(_id, min, max, step) \
{ \
.desc = { \
.name = "LDO" #_id, \
.of_match = of_match_ptr("LDO" #_id), \
.regulators_node = of_match_ptr("regulators"), \
.ops = &max8925_regulator_ldo_ops, \
.type = REGULATOR_VOLTAGE, \
.id = MAX8925_ID_LDO##_id, \
.owner = THIS_MODULE, \
.n_voltages = 64, \
.min_uV = min * 1000, \
.uV_step = step * 1000, \
}, \
.vol_reg = MAX8925_LDOVOUT##_id, \
.enable_reg = MAX8925_LDOCTL##_id, \
}
static struct max8925_regulator_info max8925_regulator_info[] = {
MAX8925_SDV(1, 637.5, 1425, 12.5),
MAX8925_SDV(2, 650, 2225, 25),
MAX8925_SDV(3, 750, 3900, 50),
MAX8925_LDO(1, 750, 3900, 50),
MAX8925_LDO(2, 650, 2250, 25),
MAX8925_LDO(3, 650, 2250, 25),
MAX8925_LDO(4, 750, 3900, 50),
MAX8925_LDO(5, 750, 3900, 50),
MAX8925_LDO(6, 750, 3900, 50),
MAX8925_LDO(7, 750, 3900, 50),
MAX8925_LDO(8, 750, 3900, 50),
MAX8925_LDO(9, 750, 3900, 50),
MAX8925_LDO(10, 750, 3900, 50),
MAX8925_LDO(11, 750, 3900, 50),
MAX8925_LDO(12, 750, 3900, 50),
MAX8925_LDO(13, 750, 3900, 50),
MAX8925_LDO(14, 750, 3900, 50),
MAX8925_LDO(15, 750, 3900, 50),
MAX8925_LDO(16, 750, 3900, 50),
MAX8925_LDO(17, 650, 2250, 25),
MAX8925_LDO(18, 650, 2250, 25),
MAX8925_LDO(19, 750, 3900, 50),
MAX8925_LDO(20, 750, 3900, 50),
};
static int max8925_regulator_probe(struct platform_device *pdev)
{
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
struct regulator_init_data *pdata = dev_get_platdata(&pdev->dev);
struct regulator_config config = { };
struct max8925_regulator_info *ri;
struct resource *res;
struct regulator_dev *rdev;
int i;
res = platform_get_resource(pdev, IORESOURCE_REG, 0);
if (!res) {
dev_err(&pdev->dev, "No REG resource!\n");
return -EINVAL;
}
for (i = 0; i < ARRAY_SIZE(max8925_regulator_info); i++) {
ri = &max8925_regulator_info[i];
if (ri->vol_reg == res->start)
break;
}
if (i == ARRAY_SIZE(max8925_regulator_info)) {
dev_err(&pdev->dev, "Failed to find regulator %llu\n",
(unsigned long long)res->start);
return -EINVAL;
}
ri->i2c = chip->i2c;
config.dev = chip->dev;
config.driver_data = ri;
if (pdata)
config.init_data = pdata;
rdev = devm_regulator_register(&pdev->dev, &ri->desc, &config);
if (IS_ERR(rdev)) {
dev_err(&pdev->dev, "failed to register regulator %s\n",
ri->desc.name);
return PTR_ERR(rdev);
}
platform_set_drvdata(pdev, rdev);
return 0;
}
static struct platform_driver max8925_regulator_driver = {
.driver = {
.name = "max8925-regulator",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
.probe = max8925_regulator_probe,
};
static int __init max8925_regulator_init(void)
{
return platform_driver_register(&max8925_regulator_driver);
}
subsys_initcall(max8925_regulator_init);
static void __exit max8925_regulator_exit(void)
{
platform_driver_unregister(&max8925_regulator_driver);
}
module_exit(max8925_regulator_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_DESCRIPTION("Regulator Driver for Maxim 8925 PMIC");
MODULE_ALIAS("platform:max8925-regulator");
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