Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) STMicroelectronics 2017
 *
 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
 */
 
#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>
#include <linux/pm_runtime.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)
 
#define STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS	10
 
struct stm32_vrefbuf {
<------>void __iomem *base;
<------>struct clk *clk;
<------>struct device *dev;
};
 
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;
<------>int ret;
 
<------>ret = pm_runtime_get_sync(priv->dev);
<------>if (ret < 0) {
<------><------>pm_runtime_put_noidle(priv->dev);
<------><------>return ret;
<------>}
 
<------>val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
<------>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);
<------>}
 
<------>pm_runtime_mark_last_busy(priv->dev);
<------>pm_runtime_put_autosuspend(priv->dev);
 
<------>return ret;
}
 
static int stm32_vrefbuf_disable(struct regulator_dev *rdev)
{
<------>struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
<------>u32 val;
<------>int ret;
 
<------>ret = pm_runtime_get_sync(priv->dev);
<------>if (ret < 0) {
<------><------>pm_runtime_put_noidle(priv->dev);
<------><------>return ret;
<------>}
 
<------>val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
<------>val &= ~STM32_ENVR;
<------>writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
 
<------>pm_runtime_mark_last_busy(priv->dev);
<------>pm_runtime_put_autosuspend(priv->dev);
 
<------>return 0;
}
 
static int stm32_vrefbuf_is_enabled(struct regulator_dev *rdev)
{
<------>struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
<------>int ret;
 
<------>ret = pm_runtime_get_sync(priv->dev);
<------>if (ret < 0) {
<------><------>pm_runtime_put_noidle(priv->dev);
<------><------>return ret;
<------>}
 
<------>ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR;
 
<------>pm_runtime_mark_last_busy(priv->dev);
<------>pm_runtime_put_autosuspend(priv->dev);
 
<------>return ret;
}
 
static int stm32_vrefbuf_set_voltage_sel(struct regulator_dev *rdev,
<------><------><------><------><------> unsigned sel)
{
<------>struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
<------>u32 val;
<------>int ret;
 
<------>ret = pm_runtime_get_sync(priv->dev);
<------>if (ret < 0) {
<------><------>pm_runtime_put_noidle(priv->dev);
<------><------>return ret;
<------>}
 
<------>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);
 
<------>pm_runtime_mark_last_busy(priv->dev);
<------>pm_runtime_put_autosuspend(priv->dev);
 
<------>return 0;
}
 
static int stm32_vrefbuf_get_voltage_sel(struct regulator_dev *rdev)
{
<------>struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
<------>u32 val;
<------>int ret;
 
<------>ret = pm_runtime_get_sync(priv->dev);
<------>if (ret < 0) {
<------><------>pm_runtime_put_noidle(priv->dev);
<------><------>return ret;
<------>}
 
<------>val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
<------>ret = FIELD_GET(STM32_VRS, val);
 
<------>pm_runtime_mark_last_busy(priv->dev);
<------>pm_runtime_put_autosuspend(priv->dev);
 
<------>return ret;
}
 
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,
<------>.off_on_delay = 1000,
<------>.type = REGULATOR_VOLTAGE,
<------>.owner = THIS_MODULE,
};
 
static int stm32_vrefbuf_probe(struct platform_device *pdev)
{
<------>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;
<------>priv->dev = &pdev->dev;
 
<------>priv->base = devm_platform_ioremap_resource(pdev, 0);
<------>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);
 
<------>pm_runtime_get_noresume(&pdev->dev);
<------>pm_runtime_set_active(&pdev->dev);
<------>pm_runtime_set_autosuspend_delay(&pdev->dev,
<------><------><------><------><------> STM32_VREFBUF_AUTO_SUSPEND_DELAY_MS);
<------>pm_runtime_use_autosuspend(&pdev->dev);
<------>pm_runtime_enable(&pdev->dev);
 
<------>ret = clk_prepare_enable(priv->clk);
<------>if (ret) {
<------><------>dev_err(&pdev->dev, "clk prepare failed with error %d\n", ret);
<------><------>goto err_pm_stop;
<------>}
 
<------>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);
 
<------>pm_runtime_mark_last_busy(&pdev->dev);
<------>pm_runtime_put_autosuspend(&pdev->dev);
 
<------>return 0;
 
err_clk_dis:
<------>clk_disable_unprepare(priv->clk);
err_pm_stop:
<------>pm_runtime_disable(&pdev->dev);
<------>pm_runtime_set_suspended(&pdev->dev);
<------>pm_runtime_put_noidle(&pdev->dev);
 
<------>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);
 
<------>pm_runtime_get_sync(&pdev->dev);
<------>regulator_unregister(rdev);
<------>clk_disable_unprepare(priv->clk);
<------>pm_runtime_disable(&pdev->dev);
<------>pm_runtime_set_suspended(&pdev->dev);
<------>pm_runtime_put_noidle(&pdev->dev);
 
<------>return 0;
};
 
static int __maybe_unused stm32_vrefbuf_runtime_suspend(struct device *dev)
{
<------>struct regulator_dev *rdev = dev_get_drvdata(dev);
<------>struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
 
<------>clk_disable_unprepare(priv->clk);
 
<------>return 0;
}
 
static int __maybe_unused stm32_vrefbuf_runtime_resume(struct device *dev)
{
<------>struct regulator_dev *rdev = dev_get_drvdata(dev);
<------>struct stm32_vrefbuf *priv = rdev_get_drvdata(rdev);
 
<------>return clk_prepare_enable(priv->clk);
}
 
static const struct dev_pm_ops stm32_vrefbuf_pm_ops = {
<------>SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
<------><------><------><------>pm_runtime_force_resume)
<------>SET_RUNTIME_PM_OPS(stm32_vrefbuf_runtime_suspend,
<------><------><------>   stm32_vrefbuf_runtime_resume,
<------><------><------>   NULL)
};
 
static const struct of_device_id __maybe_unused 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),
<------><------>.pm = &stm32_vrefbuf_pm_ops,
<------>},
};
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");