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// SPDX-License-Identifier: GPL-2.0
/*
* This file is part of STM32 DAC driver
*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
*
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include "stm32-dac-core.h"
/**
* struct stm32_dac_priv - stm32 DAC core private data
* @pclk: peripheral clock common for all DACs
* @vref: regulator reference
* @common: Common data for all DAC instances
*/
struct stm32_dac_priv {
struct clk *pclk;
struct regulator *vref;
struct stm32_dac_common common;
};
/**
* struct stm32_dac_cfg - DAC configuration
* @has_hfsel: DAC has high frequency control
*/
struct stm32_dac_cfg {
bool has_hfsel;
};
static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com)
{
return container_of(com, struct stm32_dac_priv, common);
}
static const struct regmap_config stm32_dac_regmap_cfg = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = sizeof(u32),
.max_register = 0x3fc,
};
static int stm32_dac_core_hw_start(struct device *dev)
{
struct stm32_dac_common *common = dev_get_drvdata(dev);
struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
int ret;
ret = regulator_enable(priv->vref);
if (ret < 0) {
dev_err(dev, "vref enable failed: %d\n", ret);
return ret;
}
ret = clk_prepare_enable(priv->pclk);
if (ret < 0) {
dev_err(dev, "pclk enable failed: %d\n", ret);
goto err_regulator_disable;
}
return 0;
err_regulator_disable:
regulator_disable(priv->vref);
return ret;
}
static void stm32_dac_core_hw_stop(struct device *dev)
{
struct stm32_dac_common *common = dev_get_drvdata(dev);
struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
clk_disable_unprepare(priv->pclk);
regulator_disable(priv->vref);
}
static int stm32_dac_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct stm32_dac_cfg *cfg;
struct stm32_dac_priv *priv;
struct regmap *regmap;
struct resource *res;
void __iomem *mmio;
struct reset_control *rst;
int ret;
if (!dev->of_node)
return -ENODEV;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
platform_set_drvdata(pdev, &priv->common);
cfg = (const struct stm32_dac_cfg *)
of_match_device(dev->driver->of_match_table, dev)->data;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mmio = devm_ioremap_resource(dev, res);
if (IS_ERR(mmio))
return PTR_ERR(mmio);
regmap = devm_regmap_init_mmio_clk(dev, "pclk", mmio,
&stm32_dac_regmap_cfg);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
priv->common.regmap = regmap;
priv->pclk = devm_clk_get(dev, "pclk");
if (IS_ERR(priv->pclk)) {
ret = PTR_ERR(priv->pclk);
dev_err(dev, "pclk get failed\n");
return ret;
}
priv->vref = devm_regulator_get(dev, "vref");
if (IS_ERR(priv->vref)) {
ret = PTR_ERR(priv->vref);
dev_err(dev, "vref get failed, %d\n", ret);
return ret;
}
pm_runtime_get_noresume(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
ret = stm32_dac_core_hw_start(dev);
if (ret)
goto err_pm_stop;
ret = regulator_get_voltage(priv->vref);
if (ret < 0) {
dev_err(dev, "vref get voltage failed, %d\n", ret);
goto err_hw_stop;
}
priv->common.vref_mv = ret / 1000;
dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
rst = devm_reset_control_get_optional_exclusive(dev, NULL);
if (rst) {
if (IS_ERR(rst)) {
ret = PTR_ERR(rst);
if (ret != -EPROBE_DEFER)
dev_err(dev, "reset get failed, %d\n", ret);
goto err_hw_stop;
}
reset_control_assert(rst);
udelay(2);
reset_control_deassert(rst);
}
if (cfg && cfg->has_hfsel) {
/* When clock speed is higher than 80MHz, set HFSEL */
priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL);
ret = regmap_update_bits(regmap, STM32_DAC_CR,
STM32H7_DAC_CR_HFSEL,
priv->common.hfsel ?
STM32H7_DAC_CR_HFSEL : 0);
if (ret)
goto err_hw_stop;
}
ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev);
if (ret < 0) {
dev_err(dev, "failed to populate DT children\n");
goto err_hw_stop;
}
pm_runtime_put(dev);
return 0;
err_hw_stop:
stm32_dac_core_hw_stop(dev);
err_pm_stop:
pm_runtime_disable(dev);
pm_runtime_set_suspended(dev);
pm_runtime_put_noidle(dev);
return ret;
}
static int stm32_dac_remove(struct platform_device *pdev)
{
pm_runtime_get_sync(&pdev->dev);
of_platform_depopulate(&pdev->dev);
stm32_dac_core_hw_stop(&pdev->dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
return 0;
}
static int __maybe_unused stm32_dac_core_resume(struct device *dev)
{
struct stm32_dac_common *common = dev_get_drvdata(dev);
struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
int ret;
if (priv->common.hfsel) {
/* restore hfsel (maybe lost under low power state) */
ret = regmap_update_bits(priv->common.regmap, STM32_DAC_CR,
STM32H7_DAC_CR_HFSEL,
STM32H7_DAC_CR_HFSEL);
if (ret)
return ret;
}
return pm_runtime_force_resume(dev);
}
static int __maybe_unused stm32_dac_core_runtime_suspend(struct device *dev)
{
stm32_dac_core_hw_stop(dev);
return 0;
}
static int __maybe_unused stm32_dac_core_runtime_resume(struct device *dev)
{
return stm32_dac_core_hw_start(dev);
}
static const struct dev_pm_ops stm32_dac_core_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, stm32_dac_core_resume)
SET_RUNTIME_PM_OPS(stm32_dac_core_runtime_suspend,
stm32_dac_core_runtime_resume,
NULL)
};
static const struct stm32_dac_cfg stm32h7_dac_cfg = {
.has_hfsel = true,
};
static const struct of_device_id stm32_dac_of_match[] = {
{
.compatible = "st,stm32f4-dac-core",
}, {
.compatible = "st,stm32h7-dac-core",
.data = (void *)&stm32h7_dac_cfg,
},
{},
};
MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
static struct platform_driver stm32_dac_driver = {
.probe = stm32_dac_probe,
.remove = stm32_dac_remove,
.driver = {
.name = "stm32-dac-core",
.of_match_table = stm32_dac_of_match,
.pm = &stm32_dac_core_pm_ops,
},
};
module_platform_driver(stm32_dac_driver);
MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:stm32-dac-core");
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