linux/drivers/regulator/tps6105x-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

117 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for TPS61050/61052 boost converters, typically used for white LEDs
* or audio amplifiers.
*
* Copyright (C) 2011 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/regmap.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/mfd/core.h>
#include <linux/mfd/tps6105x.h>
static const unsigned int tps6105x_voltages[] = {
4500000,
5000000,
5250000,
5000000, /* There is an additional 5V */
};
static const struct regulator_ops tps6105x_regulator_ops = {
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.is_enabled = regulator_is_enabled_regmap,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
.list_voltage = regulator_list_voltage_table,
};
static const struct regulator_desc tps6105x_regulator_desc = {
.name = "tps6105x-boost",
.of_match = of_match_ptr("regulator"),
.ops = &tps6105x_regulator_ops,
.type = REGULATOR_VOLTAGE,
.id = 0,
.owner = THIS_MODULE,
.n_voltages = ARRAY_SIZE(tps6105x_voltages),
.volt_table = tps6105x_voltages,
.vsel_reg = TPS6105X_REG_0,
.vsel_mask = TPS6105X_REG0_VOLTAGE_MASK,
.enable_reg = TPS6105X_REG_0,
.enable_mask = TPS6105X_REG0_MODE_MASK,
.enable_val = TPS6105X_REG0_MODE_VOLTAGE <<
TPS6105X_REG0_MODE_SHIFT,
};
/*
* Registers the chip as a voltage regulator
*/
static int tps6105x_regulator_probe(struct platform_device *pdev)
{
struct tps6105x *tps6105x = dev_get_platdata(&pdev->dev);
struct tps6105x_platform_data *pdata = tps6105x->pdata;
struct regulator_config config = { };
int ret;
/* This instance is not set for regulator mode so bail out */
if (pdata->mode != TPS6105X_MODE_VOLTAGE) {
dev_info(&pdev->dev,
"chip not in voltage mode mode, exit probe\n");
return 0;
}
config.dev = &tps6105x->client->dev;
config.init_data = pdata->regulator_data;
config.driver_data = tps6105x;
config.of_node = pdev->dev.parent->of_node;
config.regmap = tps6105x->regmap;
/* Register regulator with framework */
tps6105x->regulator = devm_regulator_register(&pdev->dev,
&tps6105x_regulator_desc,
&config);
if (IS_ERR(tps6105x->regulator)) {
ret = PTR_ERR(tps6105x->regulator);
dev_err(&tps6105x->client->dev,
"failed to register regulator\n");
return ret;
}
platform_set_drvdata(pdev, tps6105x);
return 0;
}
static struct platform_driver tps6105x_regulator_driver = {
.driver = {
.name = "tps6105x-regulator",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
.probe = tps6105x_regulator_probe,
};
static __init int tps6105x_regulator_init(void)
{
return platform_driver_register(&tps6105x_regulator_driver);
}
subsys_initcall(tps6105x_regulator_init);
static __exit void tps6105x_regulator_exit(void)
{
platform_driver_unregister(&tps6105x_regulator_driver);
}
module_exit(tps6105x_regulator_exit);
MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("TPS6105x regulator driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:tps6105x-regulator");