linux/drivers/regulator/sun20i-regulator.c
Samuel Holland 4e70b26c87
regulator: sun20i: Add Allwinner D1 LDOs driver
D1 contains two pairs of LDOs, "analog" LDOs and "system" LDOs. They are
similar and can share a driver, but only the system LDOs have a DT
binding defined so far.

The system LDOs have a single linear range. The voltage step is not an
integer, so a custom .list_voltage is needed to get the rounding right.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20240509153107.438220-3-wens@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2024-05-09 17:44:01 +02:00

158 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright (c) 2021-2022 Samuel Holland <samuel@sholland.org>
//
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#define SUN20I_SYS_LDO_CTRL_REG 0x150
struct sun20i_regulator_data {
const struct regulator_desc *descs;
unsigned int ndescs;
};
/* regulator_list_voltage_linear() modified for the non-integral uV_step. */
static int sun20i_d1_system_ldo_list_voltage(struct regulator_dev *rdev,
unsigned int selector)
{
const struct regulator_desc *desc = rdev->desc;
unsigned int fraction, uV;
if (selector >= desc->n_voltages)
return -EINVAL;
uV = desc->min_uV + (desc->uV_step * selector);
fraction = selector + (desc->min_uV % 4);
if (uV > 1606667)
uV += 6667;
else
fraction++;
/* Produce correctly-rounded absolute voltages. */
return uV + (fraction / 3);
}
static const struct regulator_ops sun20i_d1_system_ldo_ops = {
.list_voltage = sun20i_d1_system_ldo_list_voltage,
.map_voltage = regulator_map_voltage_ascend,
.set_voltage_sel = regulator_set_voltage_sel_regmap,
.get_voltage_sel = regulator_get_voltage_sel_regmap,
};
static const struct regulator_desc sun20i_d1_system_ldo_descs[] = {
{
.name = "ldoa",
.supply_name = "ldo-in",
.of_match = "ldoa",
.ops = &sun20i_d1_system_ldo_ops,
.type = REGULATOR_VOLTAGE,
.owner = THIS_MODULE,
.n_voltages = 32,
.min_uV = 1593333,
.uV_step = 13333, /* repeating */
.vsel_reg = SUN20I_SYS_LDO_CTRL_REG,
.vsel_mask = GENMASK(7, 0),
},
{
.name = "ldob",
.supply_name = "ldo-in",
.of_match = "ldob",
.ops = &sun20i_d1_system_ldo_ops,
.type = REGULATOR_VOLTAGE,
.owner = THIS_MODULE,
.n_voltages = 64,
.min_uV = 1166666,
.uV_step = 13333, /* repeating */
.vsel_reg = SUN20I_SYS_LDO_CTRL_REG,
.vsel_mask = GENMASK(15, 8),
},
};
static const struct sun20i_regulator_data sun20i_d1_system_ldos = {
.descs = sun20i_d1_system_ldo_descs,
.ndescs = ARRAY_SIZE(sun20i_d1_system_ldo_descs),
};
static struct regmap *sun20i_regulator_get_regmap(struct device *dev)
{
struct regmap *regmap;
/*
* First try the syscon interface. The system control device is not
* compatible with "syscon", so fall back to getting the regmap from
* its platform device. This is ugly, but required for devicetree
* backward compatibility.
*/
regmap = syscon_node_to_regmap(dev->parent->of_node);
if (!IS_ERR(regmap))
return regmap;
regmap = dev_get_regmap(dev->parent, NULL);
if (regmap)
return regmap;
return ERR_PTR(-EPROBE_DEFER);
}
static int sun20i_regulator_probe(struct platform_device *pdev)
{
const struct sun20i_regulator_data *data;
struct device *dev = &pdev->dev;
struct regulator_config config;
struct regmap *regmap;
data = of_device_get_match_data(dev);
if (!data)
return -EINVAL;
regmap = sun20i_regulator_get_regmap(dev);
if (IS_ERR(regmap))
return dev_err_probe(dev, PTR_ERR(regmap), "Failed to get regmap\n");
config = (struct regulator_config) {
.dev = dev,
.regmap = regmap,
};
for (unsigned int i = 0; i < data->ndescs; ++i) {
const struct regulator_desc *desc = &data->descs[i];
struct regulator_dev *rdev;
rdev = devm_regulator_register(dev, desc, &config);
if (IS_ERR(rdev))
return PTR_ERR(rdev);
}
return 0;
}
static const struct of_device_id sun20i_regulator_of_match[] = {
{
.compatible = "allwinner,sun20i-d1-system-ldos",
.data = &sun20i_d1_system_ldos,
},
{ },
};
MODULE_DEVICE_TABLE(of, sun20i_regulator_of_match);
static struct platform_driver sun20i_regulator_driver = {
.probe = sun20i_regulator_probe,
.driver = {
.name = "sun20i-regulator",
.of_match_table = sun20i_regulator_of_match,
},
};
module_platform_driver(sun20i_regulator_driver);
MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
MODULE_DESCRIPTION("Allwinner D1 internal LDO driver");
MODULE_LICENSE("GPL");