linux/drivers/regulator/lp873x-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

201 lines
5.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Regulator driver for LP873X PMIC
*
* Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com/
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/lp873x.h>
#define LP873X_REGULATOR(_name, _id, _of, _ops, _n, _vr, _vm, _er, _em, \
_delay, _lr, _cr) \
[_id] = { \
.desc = { \
.name = _name, \
.supply_name = _of "-in", \
.id = _id, \
.of_match = of_match_ptr(_of), \
.regulators_node = of_match_ptr("regulators"),\
.ops = &_ops, \
.n_voltages = _n, \
.type = REGULATOR_VOLTAGE, \
.owner = THIS_MODULE, \
.vsel_reg = _vr, \
.vsel_mask = _vm, \
.enable_reg = _er, \
.enable_mask = _em, \
.ramp_delay = _delay, \
.linear_ranges = _lr, \
.n_linear_ranges = ARRAY_SIZE(_lr), \
.curr_table = lp873x_buck_uA, \
.n_current_limits = ARRAY_SIZE(lp873x_buck_uA), \
.csel_reg = (_cr), \
.csel_mask = LP873X_BUCK0_CTRL_2_BUCK0_ILIM,\
}, \
.ctrl2_reg = _cr, \
}
struct lp873x_regulator {
struct regulator_desc desc;
unsigned int ctrl2_reg;
};
static const struct lp873x_regulator regulators[];
static const struct linear_range buck0_buck1_ranges[] = {
REGULATOR_LINEAR_RANGE(0, 0x0, 0x13, 0),
REGULATOR_LINEAR_RANGE(700000, 0x14, 0x17, 10000),
REGULATOR_LINEAR_RANGE(735000, 0x18, 0x9d, 5000),
REGULATOR_LINEAR_RANGE(1420000, 0x9e, 0xff, 20000),
};
static const struct linear_range ldo0_ldo1_ranges[] = {
REGULATOR_LINEAR_RANGE(800000, 0x0, 0x19, 100000),
};
static const unsigned int lp873x_buck_ramp_delay[] = {
30000, 15000, 10000, 7500, 3800, 1900, 940, 470
};
/* LP873X BUCK current limit */
static const unsigned int lp873x_buck_uA[] = {
1500000, 2000000, 2500000, 3000000, 3500000, 4000000,
};
static int lp873x_buck_set_ramp_delay(struct regulator_dev *rdev,
int ramp_delay)
{
int id = rdev_get_id(rdev);
struct lp873x *lp873 = rdev_get_drvdata(rdev);
unsigned int reg;
int ret;
if (ramp_delay <= 470)
reg = 7;
else if (ramp_delay <= 940)
reg = 6;
else if (ramp_delay <= 1900)
reg = 5;
else if (ramp_delay <= 3800)
reg = 4;
else if (ramp_delay <= 7500)
reg = 3;
else if (ramp_delay <= 10000)
reg = 2;
else if (ramp_delay <= 15000)
reg = 1;
else
reg = 0;
ret = regmap_update_bits(lp873->regmap, regulators[id].ctrl2_reg,
LP873X_BUCK0_CTRL_2_BUCK0_SLEW_RATE,
reg << __ffs(LP873X_BUCK0_CTRL_2_BUCK0_SLEW_RATE));
if (ret) {
dev_err(lp873->dev, "SLEW RATE write failed: %d\n", ret);
return ret;
}
rdev->constraints->ramp_delay = lp873x_buck_ramp_delay[reg];
return 0;
}
/* Operations permitted on BUCK0, BUCK1 */
static const struct regulator_ops lp873x_buck01_ops = {
.is_enabled = regulator_is_enabled_regmap,
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
.list_voltage = regulator_list_voltage_linear_range,
.map_voltage = regulator_map_voltage_linear_range,
.set_voltage_time_sel = regulator_set_voltage_time_sel,
.set_ramp_delay = lp873x_buck_set_ramp_delay,
.set_current_limit = regulator_set_current_limit_regmap,
.get_current_limit = regulator_get_current_limit_regmap,
};
/* Operations permitted on LDO0 and LDO1 */
static const struct regulator_ops lp873x_ldo01_ops = {
.is_enabled = regulator_is_enabled_regmap,
.enable = regulator_enable_regmap,
.disable = regulator_disable_regmap,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
.list_voltage = regulator_list_voltage_linear_range,
.map_voltage = regulator_map_voltage_linear_range,
};
static const struct lp873x_regulator regulators[] = {
LP873X_REGULATOR("BUCK0", LP873X_BUCK_0, "buck0", lp873x_buck01_ops,
256, LP873X_REG_BUCK0_VOUT,
LP873X_BUCK0_VOUT_BUCK0_VSET, LP873X_REG_BUCK0_CTRL_1,
LP873X_BUCK0_CTRL_1_BUCK0_EN, 10000,
buck0_buck1_ranges, LP873X_REG_BUCK0_CTRL_2),
LP873X_REGULATOR("BUCK1", LP873X_BUCK_1, "buck1", lp873x_buck01_ops,
256, LP873X_REG_BUCK1_VOUT,
LP873X_BUCK1_VOUT_BUCK1_VSET, LP873X_REG_BUCK1_CTRL_1,
LP873X_BUCK1_CTRL_1_BUCK1_EN, 10000,
buck0_buck1_ranges, LP873X_REG_BUCK1_CTRL_2),
LP873X_REGULATOR("LDO0", LP873X_LDO_0, "ldo0", lp873x_ldo01_ops, 26,
LP873X_REG_LDO0_VOUT, LP873X_LDO0_VOUT_LDO0_VSET,
LP873X_REG_LDO0_CTRL,
LP873X_LDO0_CTRL_LDO0_EN, 0, ldo0_ldo1_ranges, 0xFF),
LP873X_REGULATOR("LDO1", LP873X_LDO_1, "ldo1", lp873x_ldo01_ops, 26,
LP873X_REG_LDO1_VOUT, LP873X_LDO1_VOUT_LDO1_VSET,
LP873X_REG_LDO1_CTRL,
LP873X_LDO1_CTRL_LDO1_EN, 0, ldo0_ldo1_ranges, 0xFF),
};
static int lp873x_regulator_probe(struct platform_device *pdev)
{
struct lp873x *lp873 = dev_get_drvdata(pdev->dev.parent);
struct regulator_config config = { };
struct regulator_dev *rdev;
int i;
platform_set_drvdata(pdev, lp873);
config.dev = &pdev->dev;
config.dev->of_node = lp873->dev->of_node;
config.driver_data = lp873;
config.regmap = lp873->regmap;
for (i = 0; i < ARRAY_SIZE(regulators); i++) {
rdev = devm_regulator_register(&pdev->dev, &regulators[i].desc,
&config);
if (IS_ERR(rdev)) {
dev_err(lp873->dev, "failed to register %s regulator\n",
pdev->name);
return PTR_ERR(rdev);
}
}
return 0;
}
static const struct platform_device_id lp873x_regulator_id_table[] = {
{ "lp873x-regulator", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, lp873x_regulator_id_table);
static struct platform_driver lp873x_regulator_driver = {
.driver = {
.name = "lp873x-pmic",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
.probe = lp873x_regulator_probe,
.id_table = lp873x_regulator_id_table,
};
module_platform_driver(lp873x_regulator_driver);
MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
MODULE_DESCRIPTION("LP873X voltage regulator driver");
MODULE_ALIAS("platform:lp873x-pmic");
MODULE_LICENSE("GPL v2");