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>

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 7db0a29b5b8dcd04dd71b328e364688083640311..acdb02a4ac0c762e778f6fb88ba77ce38e04d58b 100644 (file)
--- 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 46fb569e6be88c09439d1fbcd79869fa070caa0c..ba15fa5f30adc818c8cdd8a804d4bbe017527c9d 100644 (file)
--- 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 (file)
index 0000000..e09be44
--- /dev/null
+++ b/drivers/regulator/sun20i-regulator.c
@@ -0,0 +1,157 @@
+// 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");