regulator: add support for the stm32-booster

Add support for the 3.3V booster regulator embedded in stm32h7 and stm32mp1
devices, that can be used to supply ADC analog input switches.

This regulator is supplied by vdda. It's controlled by using SYSCFG:
- STM32H7 has a unique register to set/clear the booster enable bit
- STM32MP1 has separate set and clear registers to configure it.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 0e7d425ba9b1baafd12ce4ad3fff01a706a19eb0..1e590ecf1a9df1432914c4d65ac003662f0df28a 100644 (file)
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -839,6 +839,17 @@ config REGULATOR_SLG51000
          The SLG51000 is seven compact and customizable low dropout
          regulators.
 
+config REGULATOR_STM32_BOOSTER
+       tristate "STMicroelectronics STM32 BOOSTER"
+       depends on ARCH_STM32 || COMPILE_TEST
+       help
+         This driver supports internal booster (3V3) embedded in some
+         STMicroelectronics STM32 chips. It can be used to supply ADC analog
+         input switches when vdda supply is below 2.7V.
+
+         This driver can also be built as a module. If so, the module
+         will be called stm32-booster.
+
 config REGULATOR_STM32_VREFBUF
        tristate "STMicroelectronics STM32 VREFBUF"
        depends on ARCH_STM32 || COMPILE_TEST

diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index c15b0b61376634f54f21686ff1b62ad69750171e..eef73b5a35a4dd1e467a26e6f07e4f7e8b8f6635 100644 (file)
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -105,6 +105,7 @@ obj-$(CONFIG_REGULATOR_S5M8767) += s5m8767.o
 obj-$(CONFIG_REGULATOR_SC2731) += sc2731-regulator.o
 obj-$(CONFIG_REGULATOR_SKY81452) += sky81452-regulator.o
 obj-$(CONFIG_REGULATOR_SLG51000) += slg51000-regulator.o
+obj-$(CONFIG_REGULATOR_STM32_BOOSTER) += stm32-booster.o
 obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o
 obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o
 obj-$(CONFIG_REGULATOR_STPMIC1) += stpmic1_regulator.o

diff --git a/drivers/regulator/stm32-booster.c b/drivers/regulator/stm32-booster.c
new file mode 100644 (file)
index 0000000..2a89766
--- /dev/null
+++ b/drivers/regulator/stm32-booster.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) STMicroelectronics 2019
+// Author(s): Fabrice Gasnier <fabrice.gasnier@st.com>.
+
+#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>
+#include <linux/regulator/of_regulator.h>
+
+/* STM32H7 SYSCFG register */
+#define STM32H7_SYSCFG_PMCR            0x04
+#define STM32H7_SYSCFG_BOOSTE_MASK     BIT(8)
+
+/* STM32MP1 SYSCFG has set and clear registers */
+#define STM32MP1_SYSCFG_PMCSETR                0x04
+#define STM32MP1_SYSCFG_PMCCLRR                0x44
+#define STM32MP1_SYSCFG_EN_BOOSTER_MASK        BIT(8)
+
+static const struct regulator_ops stm32h7_booster_ops = {
+       .list_voltage   = regulator_list_voltage_linear,
+       .enable         = regulator_enable_regmap,
+       .disable        = regulator_disable_regmap,
+       .is_enabled     = regulator_is_enabled_regmap,
+};
+
+static const struct regulator_desc stm32h7_booster_desc = {
+       .name = "booster",
+       .supply_name = "vdda",
+       .n_voltages = 1,
+       .type = REGULATOR_VOLTAGE,
+       .min_uV = 3300000,
+       .fixed_uV = 3300000,
+       .ramp_delay = 66000, /* up to 50us to stabilize */
+       .ops = &stm32h7_booster_ops,
+       .enable_reg = STM32H7_SYSCFG_PMCR,
+       .enable_mask = STM32H7_SYSCFG_BOOSTE_MASK,
+       .owner = THIS_MODULE,
+};
+
+static int stm32mp1_booster_enable(struct regulator_dev *rdev)
+{
+       return regmap_write(rdev->regmap, STM32MP1_SYSCFG_PMCSETR,
+                           STM32MP1_SYSCFG_EN_BOOSTER_MASK);
+}
+
+static int stm32mp1_booster_disable(struct regulator_dev *rdev)
+{
+       return regmap_write(rdev->regmap, STM32MP1_SYSCFG_PMCCLRR,
+                           STM32MP1_SYSCFG_EN_BOOSTER_MASK);
+}
+
+static const struct regulator_ops stm32mp1_booster_ops = {
+       .list_voltage   = regulator_list_voltage_linear,
+       .enable         = stm32mp1_booster_enable,
+       .disable        = stm32mp1_booster_disable,
+       .is_enabled     = regulator_is_enabled_regmap,
+};
+
+static const struct regulator_desc stm32mp1_booster_desc = {
+       .name = "booster",
+       .supply_name = "vdda",
+       .n_voltages = 1,
+       .type = REGULATOR_VOLTAGE,
+       .min_uV = 3300000,
+       .fixed_uV = 3300000,
+       .ramp_delay = 66000,
+       .ops = &stm32mp1_booster_ops,
+       .enable_reg = STM32MP1_SYSCFG_PMCSETR,
+       .enable_mask = STM32MP1_SYSCFG_EN_BOOSTER_MASK,
+       .owner = THIS_MODULE,
+};
+
+static int stm32_booster_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct device_node *np = pdev->dev.of_node;
+       struct regulator_config config = { };
+       const struct regulator_desc *desc;
+       struct regulator_dev *rdev;
+       struct regmap *regmap;
+       int ret;
+
+       regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+       if (IS_ERR(regmap))
+               return PTR_ERR(regmap);
+
+       desc = (const struct regulator_desc *)
+               of_match_device(dev->driver->of_match_table, dev)->data;
+
+       config.regmap = regmap;
+       config.dev = dev;
+       config.of_node = np;
+       config.init_data = of_get_regulator_init_data(dev, np, desc);
+
+       rdev = devm_regulator_register(dev, desc, &config);
+       if (IS_ERR(rdev)) {
+               ret = PTR_ERR(rdev);
+               dev_err(dev, "register failed with error %d\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static const struct of_device_id stm32_booster_of_match[] = {
+       {
+               .compatible = "st,stm32h7-booster",
+               .data = (void *)&stm32h7_booster_desc
+       }, {
+               .compatible = "st,stm32mp1-booster",
+               .data = (void *)&stm32mp1_booster_desc
+       }, {
+       },
+};
+MODULE_DEVICE_TABLE(of, stm32_booster_of_match);
+
+static struct platform_driver stm32_booster_driver = {
+       .probe = stm32_booster_probe,
+       .driver = {
+               .name  = "stm32-booster",
+               .of_match_table = of_match_ptr(stm32_booster_of_match),
+       },
+};
+module_platform_driver(stm32_booster_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 booster regulator driver");
+MODULE_ALIAS("platform:stm32-booster");