linux/drivers/regulator/pcap-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

275 lines
7.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PCAP2 Regulator Driver
*
* Copyright (c) 2009 Daniel Ribeiro <drwyrm@gmail.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/mfd/ezx-pcap.h>
static const unsigned int V1_table[] = {
2775000, 1275000, 1600000, 1725000, 1825000, 1925000, 2075000, 2275000,
};
static const unsigned int V2_table[] = {
2500000, 2775000,
};
static const unsigned int V3_table[] = {
1075000, 1275000, 1550000, 1725000, 1876000, 1950000, 2075000, 2275000,
};
static const unsigned int V4_table[] = {
1275000, 1550000, 1725000, 1875000, 1950000, 2075000, 2275000, 2775000,
};
static const unsigned int V5_table[] = {
1875000, 2275000, 2475000, 2775000,
};
static const unsigned int V6_table[] = {
2475000, 2775000,
};
static const unsigned int V7_table[] = {
1875000, 2775000,
};
#define V8_table V4_table
static const unsigned int V9_table[] = {
1575000, 1875000, 2475000, 2775000,
};
static const unsigned int V10_table[] = {
5000000,
};
static const unsigned int VAUX1_table[] = {
1875000, 2475000, 2775000, 3000000,
};
#define VAUX2_table VAUX1_table
static const unsigned int VAUX3_table[] = {
1200000, 1200000, 1200000, 1200000, 1400000, 1600000, 1800000, 2000000,
2200000, 2400000, 2600000, 2800000, 3000000, 3200000, 3400000, 3600000,
};
static const unsigned int VAUX4_table[] = {
1800000, 1800000, 3000000, 5000000,
};
static const unsigned int VSIM_table[] = {
1875000, 3000000,
};
static const unsigned int VSIM2_table[] = {
1875000,
};
static const unsigned int VVIB_table[] = {
1300000, 1800000, 2000000, 3000000,
};
static const unsigned int SW1_table[] = {
900000, 950000, 1000000, 1050000, 1100000, 1150000, 1200000, 1250000,
1300000, 1350000, 1400000, 1450000, 1500000, 1600000, 1875000, 2250000,
};
#define SW2_table SW1_table
struct pcap_regulator {
const u8 reg;
const u8 en;
const u8 index;
const u8 stby;
const u8 lowpwr;
};
#define NA 0xff
#define VREG_INFO(_vreg, _reg, _en, _index, _stby, _lowpwr) \
[_vreg] = { \
.reg = _reg, \
.en = _en, \
.index = _index, \
.stby = _stby, \
.lowpwr = _lowpwr, \
}
static struct pcap_regulator vreg_table[] = {
VREG_INFO(V1, PCAP_REG_VREG1, 1, 2, 18, 0),
VREG_INFO(V2, PCAP_REG_VREG1, 5, 6, 19, 22),
VREG_INFO(V3, PCAP_REG_VREG1, 7, 8, 20, 23),
VREG_INFO(V4, PCAP_REG_VREG1, 11, 12, 21, 24),
/* V5 STBY and LOWPWR are on PCAP_REG_VREG2 */
VREG_INFO(V5, PCAP_REG_VREG1, 15, 16, 12, 19),
VREG_INFO(V6, PCAP_REG_VREG2, 1, 2, 14, 20),
VREG_INFO(V7, PCAP_REG_VREG2, 3, 4, 15, 21),
VREG_INFO(V8, PCAP_REG_VREG2, 5, 6, 16, 22),
VREG_INFO(V9, PCAP_REG_VREG2, 9, 10, 17, 23),
VREG_INFO(V10, PCAP_REG_VREG2, 10, NA, 18, 24),
VREG_INFO(VAUX1, PCAP_REG_AUXVREG, 1, 2, 22, 23),
/* VAUX2 ... VSIM2 STBY and LOWPWR are on PCAP_REG_LOWPWR */
VREG_INFO(VAUX2, PCAP_REG_AUXVREG, 4, 5, 0, 1),
VREG_INFO(VAUX3, PCAP_REG_AUXVREG, 7, 8, 2, 3),
VREG_INFO(VAUX4, PCAP_REG_AUXVREG, 12, 13, 4, 5),
VREG_INFO(VSIM, PCAP_REG_AUXVREG, 17, 18, NA, 6),
VREG_INFO(VSIM2, PCAP_REG_AUXVREG, 16, NA, NA, 7),
VREG_INFO(VVIB, PCAP_REG_AUXVREG, 19, 20, NA, NA),
VREG_INFO(SW1, PCAP_REG_SWCTRL, 1, 2, NA, NA),
VREG_INFO(SW2, PCAP_REG_SWCTRL, 6, 7, NA, NA),
/* SW3 STBY is on PCAP_REG_AUXVREG */
VREG_INFO(SW3, PCAP_REG_SWCTRL, 11, 12, 24, NA),
/* SWxS used to control SWx voltage on standby */
/* VREG_INFO(SW1S, PCAP_REG_LOWPWR, NA, 12, NA, NA),
VREG_INFO(SW2S, PCAP_REG_LOWPWR, NA, 20, NA, NA), */
};
static int pcap_regulator_set_voltage_sel(struct regulator_dev *rdev,
unsigned selector)
{
struct pcap_regulator *vreg = &vreg_table[rdev_get_id(rdev)];
void *pcap = rdev_get_drvdata(rdev);
/* the regulator doesn't support voltage switching */
if (rdev->desc->n_voltages == 1)
return -EINVAL;
return ezx_pcap_set_bits(pcap, vreg->reg,
(rdev->desc->n_voltages - 1) << vreg->index,
selector << vreg->index);
}
static int pcap_regulator_get_voltage_sel(struct regulator_dev *rdev)
{
struct pcap_regulator *vreg = &vreg_table[rdev_get_id(rdev)];
void *pcap = rdev_get_drvdata(rdev);
u32 tmp;
if (rdev->desc->n_voltages == 1)
return 0;
ezx_pcap_read(pcap, vreg->reg, &tmp);
tmp = ((tmp >> vreg->index) & (rdev->desc->n_voltages - 1));
return tmp;
}
static int pcap_regulator_enable(struct regulator_dev *rdev)
{
struct pcap_regulator *vreg = &vreg_table[rdev_get_id(rdev)];
void *pcap = rdev_get_drvdata(rdev);
if (vreg->en == NA)
return -EINVAL;
return ezx_pcap_set_bits(pcap, vreg->reg, 1 << vreg->en, 1 << vreg->en);
}
static int pcap_regulator_disable(struct regulator_dev *rdev)
{
struct pcap_regulator *vreg = &vreg_table[rdev_get_id(rdev)];
void *pcap = rdev_get_drvdata(rdev);
if (vreg->en == NA)
return -EINVAL;
return ezx_pcap_set_bits(pcap, vreg->reg, 1 << vreg->en, 0);
}
static int pcap_regulator_is_enabled(struct regulator_dev *rdev)
{
struct pcap_regulator *vreg = &vreg_table[rdev_get_id(rdev)];
void *pcap = rdev_get_drvdata(rdev);
u32 tmp;
if (vreg->en == NA)
return -EINVAL;
ezx_pcap_read(pcap, vreg->reg, &tmp);
return (tmp >> vreg->en) & 1;
}
static const struct regulator_ops pcap_regulator_ops = {
.list_voltage = regulator_list_voltage_table,
.set_voltage_sel = pcap_regulator_set_voltage_sel,
.get_voltage_sel = pcap_regulator_get_voltage_sel,
.enable = pcap_regulator_enable,
.disable = pcap_regulator_disable,
.is_enabled = pcap_regulator_is_enabled,
};
#define VREG(_vreg) \
[_vreg] = { \
.name = #_vreg, \
.id = _vreg, \
.n_voltages = ARRAY_SIZE(_vreg##_table), \
.volt_table = _vreg##_table, \
.ops = &pcap_regulator_ops, \
.type = REGULATOR_VOLTAGE, \
.owner = THIS_MODULE, \
}
static const struct regulator_desc pcap_regulators[] = {
VREG(V1), VREG(V2), VREG(V3), VREG(V4), VREG(V5), VREG(V6), VREG(V7),
VREG(V8), VREG(V9), VREG(V10), VREG(VAUX1), VREG(VAUX2), VREG(VAUX3),
VREG(VAUX4), VREG(VSIM), VREG(VSIM2), VREG(VVIB), VREG(SW1), VREG(SW2),
};
static int pcap_regulator_probe(struct platform_device *pdev)
{
struct regulator_dev *rdev;
void *pcap = dev_get_drvdata(pdev->dev.parent);
struct regulator_config config = { };
config.dev = &pdev->dev;
config.init_data = dev_get_platdata(&pdev->dev);
config.driver_data = pcap;
rdev = devm_regulator_register(&pdev->dev, &pcap_regulators[pdev->id],
&config);
if (IS_ERR(rdev))
return PTR_ERR(rdev);
platform_set_drvdata(pdev, rdev);
return 0;
}
static struct platform_driver pcap_regulator_driver = {
.driver = {
.name = "pcap-regulator",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
.probe = pcap_regulator_probe,
};
static int __init pcap_regulator_init(void)
{
return platform_driver_register(&pcap_regulator_driver);
}
static void __exit pcap_regulator_exit(void)
{
platform_driver_unregister(&pcap_regulator_driver);
}
subsys_initcall(pcap_regulator_init);
module_exit(pcap_regulator_exit);
MODULE_AUTHOR("Daniel Ribeiro <drwyrm@gmail.com>");
MODULE_DESCRIPTION("PCAP2 Regulator Driver");
MODULE_LICENSE("GPL");