regulator: Add support for stm32-vrefbuf (0cdbf481) · Commits · 戴 / test

drivers/regulator/Kconfig

+12 −0

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		@@ -746,6 +746,18 @@ config REGULATOR_SKY81452
		This driver can also be built as a module. If so, the module
		will be called sky81452-regulator.

		config REGULATOR_STM32_VREFBUF
		tristate "STMicroelectronics STM32 VREFBUF"
		depends on ARCH_STM32 \|\| COMPILE_TEST
		help
		This driver supports STMicroelectronics STM32 VREFBUF (voltage
		reference buffer) which can be used as voltage reference for
		internal ADCs, DACs and also for external components through
		dedicated Vref+ pin.

		This driver can also be built as a module. If so, the module
		will be called stm32-vrefbuf.

		config REGULATOR_TI_ABB
		tristate "TI Adaptive Body Bias on-chip LDO"
		depends on ARCH_OMAP

drivers/regulator/Makefile

+1 −0

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		@@ -94,6 +94,7 @@ obj-$(CONFIG_REGULATOR_S2MPA01) += s2mpa01.o
		obj-$(CONFIG_REGULATOR_S2MPS11) += s2mps11.o
		obj-$(CONFIG_REGULATOR_S5M8767) += s5m8767.o
		obj-$(CONFIG_REGULATOR_SKY81452) += sky81452-regulator.o
		obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o
		obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o
		obj-$(CONFIG_REGULATOR_TI_ABB) += ti-abb-regulator.o
		obj-$(CONFIG_REGULATOR_TPS6105X) += tps6105x-regulator.o

drivers/regulator/stm32-vrefbuf.c

0 → 100644

+202 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) STMicroelectronics 2017
		*
		* Author: Fabrice Gasnier <fabrice.gasnier@st.com>
		*
		* License terms: GNU General Public License (GPL), version 2
		*/

		#include <linux/bitfield.h>
		#include <linux/clk.h>
		#include <linux/io.h>
		#include <linux/iopoll.h>
		#include <linux/module.h>
		#include <linux/of_device.h>
		#include <linux/platform_device.h>
		#include <linux/regulator/driver.h>
		#include <linux/regulator/of_regulator.h>

		/* STM32 VREFBUF registers */
		#define STM32_VREFBUF_CSR 0x00

		/* STM32 VREFBUF CSR bitfields */
		#define STM32_VRS GENMASK(6, 4)
		#define STM32_VRR BIT(3)
		#define STM32_HIZ BIT(1)
		#define STM32_ENVR BIT(0)

		struct stm32_vrefbuf {
		void __iomem *base;
		struct clk *clk;
		};

		static const unsigned int stm32_vrefbuf_voltages[] = {
		/* Matches resp. VRS = 000b, 001b, 010b, 011b */
		2500000, 2048000, 1800000, 1500000,
		};

		static int stm32_vrefbuf_enable(struct regulator_dev *rdev)
		{
		struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
		u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
		int ret;

		val = (val & ~STM32_HIZ) \| STM32_ENVR;
		writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);

		/*
		* Vrefbuf startup time depends on external capacitor: wait here for
		* VRR to be set. That means output has reached expected value.
		* ~650us sleep should be enough for caps up to 1.5uF. Use 10ms as
		* arbitrary timeout.
		*/
		ret = readl_poll_timeout(priv->base + STM32_VREFBUF_CSR, val,
		!(val & STM32_VRR), 650, 10000);
		if (ret) {
		dev_err(&rdev->dev, "stm32 vrefbuf timed out!\n");
		val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
		val = (val & ~STM32_ENVR) \| STM32_HIZ;
		writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
		}

		return ret;
		}

		static int stm32_vrefbuf_disable(struct regulator_dev *rdev)
		{
		struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
		u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);

		val = (val & ~STM32_ENVR) \| STM32_HIZ;
		writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);

		return 0;
		}

		static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev)
		{
		struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);

		return readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR;
		}

		static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev,
		unsigned sel)
		{
		struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
		u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);

		val = (val & ~STM32_VRS) \| FIELD_PREP(STM32_VRS, sel);
		writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);

		return 0;
		}

		static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev)
		{
		struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
		u32 val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);

		return FIELD_GET(STM32_VRS, val);
		}

		static const struct regulator_ops stm32_vrefbuf_volt_ops = {
		.enable = stm32_vrefbuf_enable,
		.disable = stm32_vrefbuf_disable,
		.is_enabled = stm32_vrefbuf_is_enabled,
		.get_voltage_sel = stm32_vrefbuf_get_voltage_sel,
		.set_voltage_sel = stm32_vrefbuf_set_voltage_sel,
		.list_voltage = regulator_list_voltage_table,
		};

		static const struct regulator_desc stm32_vrefbuf_regu = {
		.name = "vref",
		.supply_name = "vdda",
		.volt_table = stm32_vrefbuf_voltages,
		.n_voltages = ARRAY_SIZE(stm32_vrefbuf_voltages),
		.ops = &stm32_vrefbuf_volt_ops,
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
		};

		static int stm32_vrefbuf_probe(struct platform_device *pdev)
		{
		struct resource *res;
		struct stm32_vrefbuf *priv;
		struct regulator_config config = { };
		struct regulator_dev *rdev;
		int ret;

		priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
		if (!priv)
		return -ENOMEM;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		priv->base = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(priv->base))
		return PTR_ERR(priv->base);

		priv->clk = devm_clk_get(&pdev->dev, NULL);
		if (IS_ERR(priv->clk))
		return PTR_ERR(priv->clk);

		ret = clk_prepare_enable(priv->clk);
		if (ret) {
		dev_err(&pdev->dev, "clk prepare failed with error %d\n", ret);
		return ret;
		}

		config.dev = &pdev->dev;
		config.driver_data = priv;
		config.of_node = pdev->dev.of_node;
		config.init_data = of_get_regulator_init_data(&pdev->dev,
		pdev->dev.of_node,
		&stm32_vrefbuf_regu);

		rdev = regulator_register(&stm32_vrefbuf_regu, &config);
		if (IS_ERR(rdev)) {
		ret = PTR_ERR(rdev);
		dev_err(&pdev->dev, "register failed with error %d\n", ret);
		goto err_clk_dis;
		}
		platform_set_drvdata(pdev, rdev);

		return 0;

		err_clk_dis:
		clk_disable_unprepare(priv->clk);

		return ret;
		}

		static int stm32_vrefbuf_remove(struct platform_device *pdev)
		{
		struct regulator_dev *rdev = platform_get_drvdata(pdev);
		struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);

		regulator_unregister(rdev);
		clk_disable_unprepare(priv->clk);

		return 0;
		};

		static const struct of_device_id stm32_vrefbuf_of_match[] = {
		{ .compatible = "st,stm32-vrefbuf", },
		{},
		};
		MODULE_DEVICE_TABLE(of, stm32_vrefbuf_of_match);

		static struct platform_driver stm32_vrefbuf_driver = {
		.probe = stm32_vrefbuf_probe,
		.remove = stm32_vrefbuf_remove,
		.driver = {
		.name = "stm32-vrefbuf",
		.of_match_table = of_match_ptr(stm32_vrefbuf_of_match),
		},
		};
		module_platform_driver(stm32_vrefbuf_driver);

		MODULE_LICENSE("GPL v2");
		MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
		MODULE_DESCRIPTION("STMicroelectronics STM32 VREFBUF driver");
		MODULE_ALIAS("platform:stm32-vrefbuf");

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