[PATCH RESEND v5 2/2] regulator: sun20i: Add Allwinner D1 LDOs driver

Chen-Yu Tsai
2024-05-07T04:13:51Z

From: Samuel Holland <samuel@sholland.org>

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>
---
drivers/regulator/Kconfig | 8 ++
drivers/regulator/Makefile | 1 +
drivers/regulator/sun20i-regulator.c | 156 +++++++++++++++++++++++++++
3 files changed, 165 insertions(+)
create mode 100644 drivers/regulator/sun20i-regulator.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 7db0a29b5b8d..acdb02a4ac0c 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1415,6 +1415,14 @@ config REGULATOR_STW481X_VMMC
This driver supports the internal VMMC regulator in the STw481x
PMIC chips.

+config REGULATOR_SUN20I
+ tristate "Allwinner D1 internal LDOs"
+ depends on ARCH_SUNXI || COMPILE_TEST
+ select MFD_SYSCON
+ default ARCH_SUNXI
+ help
+ This driver supports the internal LDOs in the Allwinner D1 SoC.
+
config REGULATOR_SY7636A
tristate "Silergy SY7636A voltage regulator"
depends on MFD_SY7636A
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 46fb569e6be8..ba15fa5f30ad 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -163,6 +163,7 @@ obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o
obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o
obj-$(CONFIG_REGULATOR_STPMIC1) += stpmic1_regulator.o
obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o
+obj-$(CONFIG_REGULATOR_SUN20I) += sun20i-regulator.o
obj-$(CONFIG_REGULATOR_SY7636A) += sy7636a-regulator.o
obj-$(CONFIG_REGULATOR_SY8106A) += sy8106a-regulator.o
obj-$(CONFIG_REGULATOR_SY8824X) += sy8824x.o
diff --git a/drivers/regulator/sun20i-regulator.c b/drivers/regulator/sun20i-regulator.c
new file mode 100644
index 000000000000..8af6b8037ee0
--- /dev/null
+++ b/drivers/regulator/sun20i-regulator.c
@@ -0,0 +1,156 @@
+// 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_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");
--
2.39.2