linux/drivers/regulator/wm8994-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

241 lines
5.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
//
// wm8994-regulator.c -- Regulator driver for the WM8994
//
// Copyright 2009 Wolfson Microelectronics PLC.
//
// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/gpio/consumer.h>
#include <linux/slab.h>
#include <linux/mfd/wm8994/core.h>
#include <linux/mfd/wm8994/registers.h>
#include <linux/mfd/wm8994/pdata.h>
struct wm8994_ldo {
struct regulator_dev *regulator;
struct wm8994 *wm8994;
struct regulator_consumer_supply supply;
struct regulator_init_data init_data;
};
#define WM8994_LDO1_MAX_SELECTOR 0x7
#define WM8994_LDO2_MAX_SELECTOR 0x3
static const struct regulator_ops wm8994_ldo1_ops = {
.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,
};
static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
unsigned int selector)
{
struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
if (selector > WM8994_LDO2_MAX_SELECTOR)
return -EINVAL;
switch (ldo->wm8994->type) {
case WM8994:
return (selector * 100000) + 900000;
case WM8958:
return (selector * 100000) + 1000000;
case WM1811:
switch (selector) {
case 0:
return -EINVAL;
default:
return (selector * 100000) + 950000;
}
break;
default:
return -EINVAL;
}
}
static const struct regulator_ops wm8994_ldo2_ops = {
.list_voltage = wm8994_ldo2_list_voltage,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
};
static const struct regulator_desc wm8994_ldo_desc[] = {
{
.name = "LDO1",
.id = 1,
.type = REGULATOR_VOLTAGE,
.n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
.vsel_reg = WM8994_LDO_1,
.vsel_mask = WM8994_LDO1_VSEL_MASK,
.ops = &wm8994_ldo1_ops,
.min_uV = 2400000,
.uV_step = 100000,
.enable_time = 3000,
.off_on_delay = 36000,
.owner = THIS_MODULE,
},
{
.name = "LDO2",
.id = 2,
.type = REGULATOR_VOLTAGE,
.n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
.vsel_reg = WM8994_LDO_2,
.vsel_mask = WM8994_LDO2_VSEL_MASK,
.ops = &wm8994_ldo2_ops,
.enable_time = 3000,
.off_on_delay = 36000,
.owner = THIS_MODULE,
},
};
static const struct regulator_desc wm8958_ldo_desc[] = {
{
.name = "LDO1",
.id = 1,
.type = REGULATOR_VOLTAGE,
.n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
.vsel_reg = WM8994_LDO_1,
.vsel_mask = WM8994_LDO1_VSEL_MASK,
.ops = &wm8994_ldo1_ops,
.min_uV = 2400000,
.uV_step = 100000,
.enable_time = 3000,
.owner = THIS_MODULE,
},
{
.name = "LDO2",
.id = 2,
.type = REGULATOR_VOLTAGE,
.n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
.vsel_reg = WM8994_LDO_2,
.vsel_mask = WM8994_LDO2_VSEL_MASK,
.ops = &wm8994_ldo2_ops,
.enable_time = 3000,
.owner = THIS_MODULE,
},
};
static const struct regulator_consumer_supply wm8994_ldo_consumer[] = {
{ .supply = "AVDD1" },
{ .supply = "DCVDD" },
};
static const struct regulator_init_data wm8994_ldo_default[] = {
{
.constraints = {
.valid_ops_mask = REGULATOR_CHANGE_STATUS,
},
.num_consumer_supplies = 1,
},
{
.constraints = {
.valid_ops_mask = REGULATOR_CHANGE_STATUS,
},
.num_consumer_supplies = 1,
},
};
static int wm8994_ldo_probe(struct platform_device *pdev)
{
struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
struct wm8994_pdata *pdata = dev_get_platdata(wm8994->dev);
int id = pdev->id % ARRAY_SIZE(pdata->ldo);
struct regulator_config config = { };
struct wm8994_ldo *ldo;
struct gpio_desc *gpiod;
int ret;
dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
ldo = devm_kzalloc(&pdev->dev, sizeof(struct wm8994_ldo), GFP_KERNEL);
if (!ldo)
return -ENOMEM;
ldo->wm8994 = wm8994;
ldo->supply = wm8994_ldo_consumer[id];
ldo->supply.dev_name = dev_name(wm8994->dev);
config.dev = wm8994->dev;
config.driver_data = ldo;
config.regmap = wm8994->regmap;
config.init_data = &ldo->init_data;
/*
* Look up LDO enable GPIO from the parent device node, we don't
* use devm because the regulator core will free the GPIO
*/
gpiod = gpiod_get_optional(pdev->dev.parent,
id ? "wlf,ldo2ena" : "wlf,ldo1ena",
GPIOD_OUT_LOW |
GPIOD_FLAGS_BIT_NONEXCLUSIVE);
if (IS_ERR(gpiod))
return PTR_ERR(gpiod);
config.ena_gpiod = gpiod;
/* Use default constraints if none set up */
if (!pdata || !pdata->ldo[id].init_data || wm8994->dev->of_node) {
dev_dbg(wm8994->dev, "Using default init data, supply %s %s\n",
ldo->supply.dev_name, ldo->supply.supply);
ldo->init_data = wm8994_ldo_default[id];
ldo->init_data.consumer_supplies = &ldo->supply;
if (!gpiod)
ldo->init_data.constraints.valid_ops_mask = 0;
} else {
ldo->init_data = *pdata->ldo[id].init_data;
}
/*
* At this point the GPIO descriptor is handled over to the
* regulator core and we need not worry about it on the
* error path.
*/
if (ldo->wm8994->type == WM8994) {
ldo->regulator = devm_regulator_register(&pdev->dev,
&wm8994_ldo_desc[id],
&config);
} else {
ldo->regulator = devm_regulator_register(&pdev->dev,
&wm8958_ldo_desc[id],
&config);
}
if (IS_ERR(ldo->regulator)) {
ret = PTR_ERR(ldo->regulator);
dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
id + 1, ret);
return ret;
}
platform_set_drvdata(pdev, ldo);
return 0;
}
static struct platform_driver wm8994_ldo_driver = {
.probe = wm8994_ldo_probe,
.driver = {
.name = "wm8994-ldo",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
};
module_platform_driver(wm8994_ldo_driver);
/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM8994 LDO driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8994-ldo");