drivers/iio/adc/stm32-dfsdm-core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * This file is part the core part STM32 DFSDM driver
  *
  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
  * Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics.
  */

 #include <linux/clk.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>

 #include "stm32-dfsdm.h"

 struct stm32_dfsdm_dev_data {
 	unsigned int num_filters;
 	unsigned int num_channels;
 	const struct regmap_config *regmap_cfg;
 };

 #define STM32H7_DFSDM_NUM_FILTERS	4
 #define STM32H7_DFSDM_NUM_CHANNELS	8
 #define STM32MP1_DFSDM_NUM_FILTERS	6
 #define STM32MP1_DFSDM_NUM_CHANNELS	8

 static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
 {
 	if (reg < DFSDM_FILTER_BASE_ADR)
 		return false;

 	/*
 	 * Mask is done on register to avoid to list registers of all
 	 * filter instances.
 	 */
 	switch (reg & DFSDM_FILTER_REG_MASK) {
 	case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK:
 	case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK:
 	case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK:
 	case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK:
 		return true;
 	}

 	return false;
 }

 static const struct regmap_config stm32h7_dfsdm_regmap_cfg = {
 	.reg_bits = 32,
 	.val_bits = 32,
 	.reg_stride = sizeof(u32),
 	.max_register = 0x2B8,
 	.volatile_reg = stm32_dfsdm_volatile_reg,
 	.fast_io = true,
 };

 static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = {
 	.num_filters = STM32H7_DFSDM_NUM_FILTERS,
 	.num_channels = STM32H7_DFSDM_NUM_CHANNELS,
 	.regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
 };

 static const struct regmap_config stm32mp1_dfsdm_regmap_cfg = {
 	.reg_bits = 32,
 	.val_bits = 32,
 	.reg_stride = sizeof(u32),
 	.max_register = 0x7fc,
 	.volatile_reg = stm32_dfsdm_volatile_reg,
 	.fast_io = true,
 };

 static const struct stm32_dfsdm_dev_data stm32mp1_dfsdm_data = {
 	.num_filters = STM32MP1_DFSDM_NUM_FILTERS,
 	.num_channels = STM32MP1_DFSDM_NUM_CHANNELS,
 	.regmap_cfg = &stm32mp1_dfsdm_regmap_cfg,
 };

 struct dfsdm_priv {
 	struct platform_device *pdev; /* platform device */

 	struct stm32_dfsdm dfsdm; /* common data exported for all instances */

 	unsigned int spi_clk_out_div; /* SPI clkout divider value */
 	atomic_t n_active_ch;	/* number of current active channels */

 	struct clk *clk; /* DFSDM clock */
 	struct clk *aclk; /* audio clock */
 };

 static inline struct dfsdm_priv *to_stm32_dfsdm_priv(struct stm32_dfsdm *dfsdm)
 {
 	return container_of(dfsdm, struct dfsdm_priv, dfsdm);
 }

 static int stm32_dfsdm_clk_prepare_enable(struct stm32_dfsdm *dfsdm)
 {
 	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
 	int ret;

 	ret = clk_prepare_enable(priv->clk);
 	if (ret || !priv->aclk)
 		return ret;

 	ret = clk_prepare_enable(priv->aclk);
 	if (ret)
 		clk_disable_unprepare(priv->clk);

 	return ret;
 }

 static void stm32_dfsdm_clk_disable_unprepare(struct stm32_dfsdm *dfsdm)
 {
 	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);

 	if (priv->aclk)
 		clk_disable_unprepare(priv->aclk);
 	clk_disable_unprepare(priv->clk);
 }

 /**
  * stm32_dfsdm_start_dfsdm - start global dfsdm interface.
  *
  * Enable interface if n_active_ch is not null.
  * @dfsdm: Handle used to retrieve dfsdm context.
  */
 int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
 {
 	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
 	struct device *dev = &priv->pdev->dev;
 	unsigned int clk_div = priv->spi_clk_out_div, clk_src;
 	int ret;

 	if (atomic_inc_return(&priv->n_active_ch) == 1) {
 		ret = pm_runtime_get_sync(dev);
 		if (ret < 0) {
 			pm_runtime_put_noidle(dev);
 			goto error_ret;
 		}

 		/* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */
 		clk_src = priv->aclk ? 1 : 0;
 		ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
 					 DFSDM_CHCFGR1_CKOUTSRC_MASK,
 					 DFSDM_CHCFGR1_CKOUTSRC(clk_src));
 		if (ret < 0)
 			goto pm_put;

 		/* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */
 		ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
 					 DFSDM_CHCFGR1_CKOUTDIV_MASK,
 					 DFSDM_CHCFGR1_CKOUTDIV(clk_div));
 		if (ret < 0)
 			goto pm_put;

 		/* Global enable of DFSDM interface */
 		ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
 					 DFSDM_CHCFGR1_DFSDMEN_MASK,
 					 DFSDM_CHCFGR1_DFSDMEN(1));
 		if (ret < 0)
 			goto pm_put;
 	}

 	dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
 		atomic_read(&priv->n_active_ch));

 	return 0;

 pm_put:
 	pm_runtime_put_sync(dev);
 error_ret:
 	atomic_dec(&priv->n_active_ch);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);

 /**
  * stm32_dfsdm_stop_dfsdm - stop global DFSDM interface.
  *
  * Disable interface if n_active_ch is null
  * @dfsdm: Handle used to retrieve dfsdm context.
  */
 int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
 {
 	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
 	int ret;

 	if (atomic_dec_and_test(&priv->n_active_ch)) {
 		/* Global disable of DFSDM interface */
 		ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
 					 DFSDM_CHCFGR1_DFSDMEN_MASK,
 					 DFSDM_CHCFGR1_DFSDMEN(0));
 		if (ret < 0)
 			return ret;

 		/* Stop SPI CLKOUT */
 		ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
 					 DFSDM_CHCFGR1_CKOUTDIV_MASK,
 					 DFSDM_CHCFGR1_CKOUTDIV(0));
 		if (ret < 0)
 			return ret;

 		pm_runtime_put_sync(&priv->pdev->dev);
 	}
 	dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
 		atomic_read(&priv->n_active_ch));

 	return 0;
 }
 EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm);

 static int stm32_dfsdm_parse_of(struct platform_device *pdev,
 				struct dfsdm_priv *priv)
 {
 	struct device_node *node = pdev->dev.of_node;
 	struct resource *res;
 	unsigned long clk_freq, divider;
 	unsigned int spi_freq, rem;
 	int ret;

 	if (!node)
 		return -EINVAL;

 	priv->dfsdm.base = devm_platform_get_and_ioremap_resource(pdev, 0,
 							&res);
 	if (IS_ERR(priv->dfsdm.base))
 		return PTR_ERR(priv->dfsdm.base);

 	priv->dfsdm.phys_base = res->start;

 	/*
 	 * "dfsdm" clock is mandatory for DFSDM peripheral clocking.
 	 * "dfsdm" or "audio" clocks can be used as source clock for
 	 * the SPI clock out signal and internal processing, depending
 	 * on use case.
 	 */
 	priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
 	if (IS_ERR(priv->clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
 				     "Failed to get clock\n");

 	priv->aclk = devm_clk_get(&pdev->dev, "audio");
 	if (IS_ERR(priv->aclk))
 		priv->aclk = NULL;

 	if (priv->aclk)
 		clk_freq = clk_get_rate(priv->aclk);
 	else
 		clk_freq = clk_get_rate(priv->clk);

 	/* SPI clock out frequency */
 	ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
 				   &spi_freq);
 	if (ret < 0) {
 		/* No SPI master mode */
 		return 0;
 	}

 	divider = div_u64_rem(clk_freq, spi_freq, &rem);
 	/* Round up divider when ckout isn't precise, not to exceed spi_freq */
 	if (rem)
 		divider++;

 	/* programmable divider is in range of [2:256] */
 	if (divider < 2 || divider > 256) {
 		dev_err(&pdev->dev, "spi-max-frequency not achievable\n");
 		return -EINVAL;
 	}

 	/* SPI clock output divider is: divider = CKOUTDIV + 1 */
 	priv->spi_clk_out_div = divider - 1;
 	priv->dfsdm.spi_master_freq = clk_freq / (priv->spi_clk_out_div + 1);

 	if (rem) {
 		dev_warn(&pdev->dev, "SPI clock not accurate\n");
 		dev_warn(&pdev->dev, "%ld = %d * %d + %d\n",
 			 clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem);
 	}

 	return 0;
 };

 static const struct of_device_id stm32_dfsdm_of_match[] = {
 	{
 		.compatible = "st,stm32h7-dfsdm",
 		.data = &stm32h7_dfsdm_data,
 	},
 	{
 		.compatible = "st,stm32mp1-dfsdm",
 		.data = &stm32mp1_dfsdm_data,
 	},
 	{}
 };
 MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);

 static int stm32_dfsdm_probe(struct platform_device *pdev)
 {
 	struct dfsdm_priv *priv;
 	const struct stm32_dfsdm_dev_data *dev_data;
 	struct stm32_dfsdm *dfsdm;
 	int ret;

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

 	priv->pdev = pdev;

 	dev_data = of_device_get_match_data(&pdev->dev);

 	dfsdm = &priv->dfsdm;
 	dfsdm->fl_list = devm_kcalloc(&pdev->dev, dev_data->num_filters,
 				      sizeof(*dfsdm->fl_list), GFP_KERNEL);
 	if (!dfsdm->fl_list)
 		return -ENOMEM;

 	dfsdm->num_fls = dev_data->num_filters;
 	dfsdm->ch_list = devm_kcalloc(&pdev->dev, dev_data->num_channels,
 				      sizeof(*dfsdm->ch_list),
 				      GFP_KERNEL);
 	if (!dfsdm->ch_list)
 		return -ENOMEM;
 	dfsdm->num_chs = dev_data->num_channels;

 	ret = stm32_dfsdm_parse_of(pdev, priv);
 	if (ret < 0)
 		return ret;

 	dfsdm->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dfsdm",
 						  dfsdm->base,
 						  dev_data->regmap_cfg);
 	if (IS_ERR(dfsdm->regmap)) {
 		ret = PTR_ERR(dfsdm->regmap);
 		dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n",
 			__func__, ret);
 		return ret;
 	}

 	platform_set_drvdata(pdev, dfsdm);

 	ret = stm32_dfsdm_clk_prepare_enable(dfsdm);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to start clock\n");
 		return ret;
 	}

 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);

 	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
 	if (ret)
 		goto pm_put;

 	pm_runtime_put(&pdev->dev);

 	return 0;

 pm_put:
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
 	stm32_dfsdm_clk_disable_unprepare(dfsdm);

 	return ret;
 }

 static int stm32_dfsdm_core_remove(struct platform_device *pdev)
 {
 	struct stm32_dfsdm *dfsdm = platform_get_drvdata(pdev);

 	pm_runtime_get_sync(&pdev->dev);
 	of_platform_depopulate(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
 	stm32_dfsdm_clk_disable_unprepare(dfsdm);

 	return 0;
 }

 static int __maybe_unused stm32_dfsdm_core_suspend(struct device *dev)
 {
 	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
 	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
 	int ret;

 	ret = pm_runtime_force_suspend(dev);
 	if (ret)
 		return ret;

 	/* Balance devm_regmap_init_mmio_clk() clk_prepare() */
 	clk_unprepare(priv->clk);

 	return pinctrl_pm_select_sleep_state(dev);
 }

 static int __maybe_unused stm32_dfsdm_core_resume(struct device *dev)
 {
 	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
 	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
 	int ret;

 	ret = pinctrl_pm_select_default_state(dev);
 	if (ret)
 		return ret;

 	ret = clk_prepare(priv->clk);
 	if (ret)
 		return ret;

 	return pm_runtime_force_resume(dev);
 }

 static int __maybe_unused stm32_dfsdm_core_runtime_suspend(struct device *dev)
 {
 	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);

 	stm32_dfsdm_clk_disable_unprepare(dfsdm);

 	return 0;
 }

 static int __maybe_unused stm32_dfsdm_core_runtime_resume(struct device *dev)
 {
 	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);

 	return stm32_dfsdm_clk_prepare_enable(dfsdm);
 }

 static const struct dev_pm_ops stm32_dfsdm_core_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(stm32_dfsdm_core_suspend,
 				stm32_dfsdm_core_resume)
 	SET_RUNTIME_PM_OPS(stm32_dfsdm_core_runtime_suspend,
 			   stm32_dfsdm_core_runtime_resume,
 			   NULL)
 };

 static struct platform_driver stm32_dfsdm_driver = {
 	.probe = stm32_dfsdm_probe,
 	.remove = stm32_dfsdm_core_remove,
 	.driver = {
 		.name = "stm32-dfsdm",
 		.of_match_table = stm32_dfsdm_of_match,
 		.pm = &stm32_dfsdm_core_pm_ops,
 	},
 };

 module_platform_driver(stm32_dfsdm_driver);

 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
 MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* This file is part the core part STM32 DFSDM driver
	*
	* Copyright (C) 2017, STMicroelectronics - All Rights Reserved
	* Author(s): Arnaud Pouliquen <arnaud.pouliquen@st.com> for STMicroelectronics.
	*/

	#include <linux/clk.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/pinctrl/consumer.h>
	#include <linux/pm_runtime.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>

	#include "stm32-dfsdm.h"

	struct stm32_dfsdm_dev_data {
	unsigned int num_filters;
	unsigned int num_channels;
	const struct regmap_config *regmap_cfg;
	};

	#define STM32H7_DFSDM_NUM_FILTERS 4
	#define STM32H7_DFSDM_NUM_CHANNELS 8
	#define STM32MP1_DFSDM_NUM_FILTERS 6
	#define STM32MP1_DFSDM_NUM_CHANNELS 8

	static bool stm32_dfsdm_volatile_reg(struct device *dev, unsigned int reg)
	{
	if (reg < DFSDM_FILTER_BASE_ADR)
	return false;

	/*
	* Mask is done on register to avoid to list registers of all
	* filter instances.
	*/
	switch (reg & DFSDM_FILTER_REG_MASK) {
	case DFSDM_CR1(0) & DFSDM_FILTER_REG_MASK:
	case DFSDM_ISR(0) & DFSDM_FILTER_REG_MASK:
	case DFSDM_JDATAR(0) & DFSDM_FILTER_REG_MASK:
	case DFSDM_RDATAR(0) & DFSDM_FILTER_REG_MASK:
	return true;
	}

	return false;
	}

	static const struct regmap_config stm32h7_dfsdm_regmap_cfg = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = sizeof(u32),
	.max_register = 0x2B8,
	.volatile_reg = stm32_dfsdm_volatile_reg,
	.fast_io = true,
	};

	static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_data = {
	.num_filters = STM32H7_DFSDM_NUM_FILTERS,
	.num_channels = STM32H7_DFSDM_NUM_CHANNELS,
	.regmap_cfg = &stm32h7_dfsdm_regmap_cfg,
	};

	static const struct regmap_config stm32mp1_dfsdm_regmap_cfg = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = sizeof(u32),
	.max_register = 0x7fc,
	.volatile_reg = stm32_dfsdm_volatile_reg,
	.fast_io = true,
	};

	static const struct stm32_dfsdm_dev_data stm32mp1_dfsdm_data = {
	.num_filters = STM32MP1_DFSDM_NUM_FILTERS,
	.num_channels = STM32MP1_DFSDM_NUM_CHANNELS,
	.regmap_cfg = &stm32mp1_dfsdm_regmap_cfg,
	};

	struct dfsdm_priv {
	struct platform_device pdev; / platform device */

	struct stm32_dfsdm dfsdm; /* common data exported for all instances */

	unsigned int spi_clk_out_div; /* SPI clkout divider value */
	atomic_t n_active_ch; /* number of current active channels */

	struct clk clk; / DFSDM clock */
	struct clk aclk; / audio clock */
	};

	static inline struct dfsdm_priv to_stm32_dfsdm_priv(struct stm32_dfsdm dfsdm)
	{
	return container_of(dfsdm, struct dfsdm_priv, dfsdm);
	}

	static int stm32_dfsdm_clk_prepare_enable(struct stm32_dfsdm *dfsdm)
	{
	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
	int ret;

	ret = clk_prepare_enable(priv->clk);
	if (ret \|\| !priv->aclk)
	return ret;

	ret = clk_prepare_enable(priv->aclk);
	if (ret)
	clk_disable_unprepare(priv->clk);

	return ret;
	}

	static void stm32_dfsdm_clk_disable_unprepare(struct stm32_dfsdm *dfsdm)
	{
	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);

	if (priv->aclk)
	clk_disable_unprepare(priv->aclk);
	clk_disable_unprepare(priv->clk);
	}

	/**
	* stm32_dfsdm_start_dfsdm - start global dfsdm interface.
	*
	* Enable interface if n_active_ch is not null.
	* @dfsdm: Handle used to retrieve dfsdm context.
	*/
	int stm32_dfsdm_start_dfsdm(struct stm32_dfsdm *dfsdm)
	{
	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
	struct device *dev = &priv->pdev->dev;
	unsigned int clk_div = priv->spi_clk_out_div, clk_src;
	int ret;

	if (atomic_inc_return(&priv->n_active_ch) == 1) {
	ret = pm_runtime_get_sync(dev);
	if (ret < 0) {
	pm_runtime_put_noidle(dev);
	goto error_ret;
	}

	/* select clock source, e.g. 0 for "dfsdm" or 1 for "audio" */
	clk_src = priv->aclk ? 1 : 0;
	ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
	DFSDM_CHCFGR1_CKOUTSRC_MASK,
	DFSDM_CHCFGR1_CKOUTSRC(clk_src));
	if (ret < 0)
	goto pm_put;

	/* Output the SPI CLKOUT (if clk_div == 0 clock if OFF) */
	ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
	DFSDM_CHCFGR1_CKOUTDIV_MASK,
	DFSDM_CHCFGR1_CKOUTDIV(clk_div));
	if (ret < 0)
	goto pm_put;

	/* Global enable of DFSDM interface */
	ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
	DFSDM_CHCFGR1_DFSDMEN_MASK,
	DFSDM_CHCFGR1_DFSDMEN(1));
	if (ret < 0)
	goto pm_put;
	}

	dev_dbg(dev, "%s: n_active_ch %d\n", __func__,
	atomic_read(&priv->n_active_ch));

	return 0;

	pm_put:
	pm_runtime_put_sync(dev);
	error_ret:
	atomic_dec(&priv->n_active_ch);

	return ret;
	}
	EXPORT_SYMBOL_GPL(stm32_dfsdm_start_dfsdm);

	/**
	* stm32_dfsdm_stop_dfsdm - stop global DFSDM interface.
	*
	* Disable interface if n_active_ch is null
	* @dfsdm: Handle used to retrieve dfsdm context.
	*/
	int stm32_dfsdm_stop_dfsdm(struct stm32_dfsdm *dfsdm)
	{
	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
	int ret;

	if (atomic_dec_and_test(&priv->n_active_ch)) {
	/* Global disable of DFSDM interface */
	ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
	DFSDM_CHCFGR1_DFSDMEN_MASK,
	DFSDM_CHCFGR1_DFSDMEN(0));
	if (ret < 0)
	return ret;

	/* Stop SPI CLKOUT */
	ret = regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(0),
	DFSDM_CHCFGR1_CKOUTDIV_MASK,
	DFSDM_CHCFGR1_CKOUTDIV(0));
	if (ret < 0)
	return ret;

	pm_runtime_put_sync(&priv->pdev->dev);
	}
	dev_dbg(&priv->pdev->dev, "%s: n_active_ch %d\n", __func__,
	atomic_read(&priv->n_active_ch));

	return 0;
	}
	EXPORT_SYMBOL_GPL(stm32_dfsdm_stop_dfsdm);

	static int stm32_dfsdm_parse_of(struct platform_device *pdev,
	struct dfsdm_priv *priv)
	{
	struct device_node *node = pdev->dev.of_node;
	struct resource *res;
	unsigned long clk_freq, divider;
	unsigned int spi_freq, rem;
	int ret;

	if (!node)
	return -EINVAL;

	priv->dfsdm.base = devm_platform_get_and_ioremap_resource(pdev, 0,
	&res);
	if (IS_ERR(priv->dfsdm.base))
	return PTR_ERR(priv->dfsdm.base);

	priv->dfsdm.phys_base = res->start;

	/*
	* "dfsdm" clock is mandatory for DFSDM peripheral clocking.
	* "dfsdm" or "audio" clocks can be used as source clock for
	* the SPI clock out signal and internal processing, depending
	* on use case.
	*/
	priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
	if (IS_ERR(priv->clk))
	return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
	"Failed to get clock\n");

	priv->aclk = devm_clk_get(&pdev->dev, "audio");
	if (IS_ERR(priv->aclk))
	priv->aclk = NULL;

	if (priv->aclk)
	clk_freq = clk_get_rate(priv->aclk);
	else
	clk_freq = clk_get_rate(priv->clk);

	/* SPI clock out frequency */
	ret = of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
	&spi_freq);
	if (ret < 0) {
	/* No SPI master mode */
	return 0;
	}

	divider = div_u64_rem(clk_freq, spi_freq, &rem);
	/* Round up divider when ckout isn't precise, not to exceed spi_freq */
	if (rem)
	divider++;

	/* programmable divider is in range of [2:256] */
	if (divider < 2 \|\| divider > 256) {
	dev_err(&pdev->dev, "spi-max-frequency not achievable\n");
	return -EINVAL;
	}

	/* SPI clock output divider is: divider = CKOUTDIV + 1 */
	priv->spi_clk_out_div = divider - 1;
	priv->dfsdm.spi_master_freq = clk_freq / (priv->spi_clk_out_div + 1);

	if (rem) {
	dev_warn(&pdev->dev, "SPI clock not accurate\n");
	dev_warn(&pdev->dev, "%ld = %d * %d + %d\n",
	clk_freq, spi_freq, priv->spi_clk_out_div + 1, rem);
	}

	return 0;
	};

	static const struct of_device_id stm32_dfsdm_of_match[] = {
	{
	.compatible = "st,stm32h7-dfsdm",
	.data = &stm32h7_dfsdm_data,
	},
	{
	.compatible = "st,stm32mp1-dfsdm",
	.data = &stm32mp1_dfsdm_data,
	},
	{}
	};
	MODULE_DEVICE_TABLE(of, stm32_dfsdm_of_match);

	static int stm32_dfsdm_probe(struct platform_device *pdev)
	{
	struct dfsdm_priv *priv;
	const struct stm32_dfsdm_dev_data *dev_data;
	struct stm32_dfsdm *dfsdm;
	int ret;

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

	priv->pdev = pdev;

	dev_data = of_device_get_match_data(&pdev->dev);

	dfsdm = &priv->dfsdm;
	dfsdm->fl_list = devm_kcalloc(&pdev->dev, dev_data->num_filters,
	sizeof(*dfsdm->fl_list), GFP_KERNEL);
	if (!dfsdm->fl_list)
	return -ENOMEM;

	dfsdm->num_fls = dev_data->num_filters;
	dfsdm->ch_list = devm_kcalloc(&pdev->dev, dev_data->num_channels,
	sizeof(*dfsdm->ch_list),
	GFP_KERNEL);
	if (!dfsdm->ch_list)
	return -ENOMEM;
	dfsdm->num_chs = dev_data->num_channels;

	ret = stm32_dfsdm_parse_of(pdev, priv);
	if (ret < 0)
	return ret;

	dfsdm->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dfsdm",
	dfsdm->base,
	dev_data->regmap_cfg);
	if (IS_ERR(dfsdm->regmap)) {
	ret = PTR_ERR(dfsdm->regmap);
	dev_err(&pdev->dev, "%s: Failed to allocate regmap: %d\n",
	__func__, ret);
	return ret;
	}

	platform_set_drvdata(pdev, dfsdm);

	ret = stm32_dfsdm_clk_prepare_enable(dfsdm);
	if (ret) {
	dev_err(&pdev->dev, "Failed to start clock\n");
	return ret;
	}

	pm_runtime_get_noresume(&pdev->dev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
	if (ret)
	goto pm_put;

	pm_runtime_put(&pdev->dev);

	return 0;

	pm_put:
	pm_runtime_disable(&pdev->dev);
	pm_runtime_set_suspended(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);
	stm32_dfsdm_clk_disable_unprepare(dfsdm);

	return ret;
	}

	static int stm32_dfsdm_core_remove(struct platform_device *pdev)
	{
	struct stm32_dfsdm *dfsdm = platform_get_drvdata(pdev);

	pm_runtime_get_sync(&pdev->dev);
	of_platform_depopulate(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	pm_runtime_set_suspended(&pdev->dev);
	pm_runtime_put_noidle(&pdev->dev);
	stm32_dfsdm_clk_disable_unprepare(dfsdm);

	return 0;
	}

	static int __maybe_unused stm32_dfsdm_core_suspend(struct device *dev)
	{
	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
	int ret;

	ret = pm_runtime_force_suspend(dev);
	if (ret)
	return ret;

	/* Balance devm_regmap_init_mmio_clk() clk_prepare() */
	clk_unprepare(priv->clk);

	return pinctrl_pm_select_sleep_state(dev);
	}

	static int __maybe_unused stm32_dfsdm_core_resume(struct device *dev)
	{
	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);
	struct dfsdm_priv *priv = to_stm32_dfsdm_priv(dfsdm);
	int ret;

	ret = pinctrl_pm_select_default_state(dev);
	if (ret)
	return ret;

	ret = clk_prepare(priv->clk);
	if (ret)
	return ret;

	return pm_runtime_force_resume(dev);
	}

	static int __maybe_unused stm32_dfsdm_core_runtime_suspend(struct device *dev)
	{
	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);

	stm32_dfsdm_clk_disable_unprepare(dfsdm);

	return 0;
	}

	static int __maybe_unused stm32_dfsdm_core_runtime_resume(struct device *dev)
	{
	struct stm32_dfsdm *dfsdm = dev_get_drvdata(dev);

	return stm32_dfsdm_clk_prepare_enable(dfsdm);
	}

	static const struct dev_pm_ops stm32_dfsdm_core_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(stm32_dfsdm_core_suspend,
	stm32_dfsdm_core_resume)
	SET_RUNTIME_PM_OPS(stm32_dfsdm_core_runtime_suspend,
	stm32_dfsdm_core_runtime_resume,
	NULL)
	};

	static struct platform_driver stm32_dfsdm_driver = {
	.probe = stm32_dfsdm_probe,
	.remove = stm32_dfsdm_core_remove,
	.driver = {
	.name = "stm32-dfsdm",
	.of_match_table = stm32_dfsdm_of_match,
	.pm = &stm32_dfsdm_core_pm_ops,
	},
	};

	module_platform_driver(stm32_dfsdm_driver);

	MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
	MODULE_DESCRIPTION("STMicroelectronics STM32 dfsdm driver");
	MODULE_LICENSE("GPL v2");