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/*
* This file is part of STM32 DAC driver
*
* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
* Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
*
* License type: GPLv2
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of_platform.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
* @rst: peripheral reset control
* @vref: regulator reference
* @common: Common data for all DAC instances
*/
struct stm32_dac_priv {
struct clk *pclk;
struct reset_control *rst;
struct regulator *vref;
struct stm32_dac_common common;
};
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_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct stm32_dac_priv *priv;
struct regmap *regmap;
struct resource *res;
void __iomem *mmio;
int ret;
if (!dev->of_node)
return -ENODEV;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
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(dev, mmio, &stm32_dac_regmap_cfg);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
priv->common.regmap = regmap;
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;
}
ret = regulator_enable(priv->vref);
if (ret < 0) {
dev_err(dev, "vref enable failed\n");
return ret;
}
ret = regulator_get_voltage(priv->vref);
if (ret < 0) {
dev_err(dev, "vref get voltage failed, %d\n", ret);
goto err_vref;
}
priv->common.vref_mv = ret / 1000;
dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
priv->pclk = devm_clk_get(dev, "pclk");
if (IS_ERR(priv->pclk)) {
ret = PTR_ERR(priv->pclk);
dev_err(dev, "pclk get failed\n");
goto err_vref;
}
ret = clk_prepare_enable(priv->pclk);
if (ret < 0) {
dev_err(dev, "pclk enable failed\n");
goto err_vref;
}
priv->rst = devm_reset_control_get(dev, NULL);
if (!IS_ERR(priv->rst)) {
reset_control_assert(priv->rst);
udelay(2);
reset_control_deassert(priv->rst);
}
/* 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_pclk;
platform_set_drvdata(pdev, &priv->common);
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_pclk;
}
return 0;
err_pclk:
clk_disable_unprepare(priv->pclk);
err_vref:
regulator_disable(priv->vref);
return ret;
}
static int stm32_dac_remove(struct platform_device *pdev)
{
struct stm32_dac_common *common = platform_get_drvdata(pdev);
struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
of_platform_depopulate(&pdev->dev);
clk_disable_unprepare(priv->pclk);
regulator_disable(priv->vref);
return 0;
}
static const struct of_device_id stm32_dac_of_match[] = {
{ .compatible = "st,stm32h7-dac-core", },
{},
};
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,
},
};
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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