drivers/iio/adc/mt6577_auxadc.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (c) 2016 MediaTek Inc.
  * Author: Zhiyong Tao <zhiyong.tao@mediatek.com>
  *
  * 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.
  */

 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/iopoll.h>
 #include <linux/io.h>
 #include <linux/iio/iio.h>

 /* Register definitions */
 #define MT6577_AUXADC_CON0                    0x00
 #define MT6577_AUXADC_CON1                    0x04
 #define MT6577_AUXADC_CON2                    0x10
 #define MT6577_AUXADC_STA                     BIT(0)

 #define MT6577_AUXADC_DAT0                    0x14
 #define MT6577_AUXADC_RDY0                    BIT(12)

 #define MT6577_AUXADC_MISC                    0x94
 #define MT6577_AUXADC_PDN_EN                  BIT(14)

 #define MT6577_AUXADC_DAT_MASK                0xfff
 #define MT6577_AUXADC_SLEEP_US                1000
 #define MT6577_AUXADC_TIMEOUT_US              10000
 #define MT6577_AUXADC_POWER_READY_MS          1
 #define MT6577_AUXADC_SAMPLE_READY_US         25

 struct mt6577_auxadc_device {
 	void __iomem *reg_base;
 	struct clk *adc_clk;
 	struct mutex lock;
 };

 #define MT6577_AUXADC_CHANNEL(idx) {				    \
 		.type = IIO_VOLTAGE,				    \
 		.indexed = 1,					    \
 		.channel = (idx),				    \
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
 }

 static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = {
 	MT6577_AUXADC_CHANNEL(0),
 	MT6577_AUXADC_CHANNEL(1),
 	MT6577_AUXADC_CHANNEL(2),
 	MT6577_AUXADC_CHANNEL(3),
 	MT6577_AUXADC_CHANNEL(4),
 	MT6577_AUXADC_CHANNEL(5),
 	MT6577_AUXADC_CHANNEL(6),
 	MT6577_AUXADC_CHANNEL(7),
 	MT6577_AUXADC_CHANNEL(8),
 	MT6577_AUXADC_CHANNEL(9),
 	MT6577_AUXADC_CHANNEL(10),
 	MT6577_AUXADC_CHANNEL(11),
 	MT6577_AUXADC_CHANNEL(12),
 	MT6577_AUXADC_CHANNEL(13),
 	MT6577_AUXADC_CHANNEL(14),
 	MT6577_AUXADC_CHANNEL(15),
 };

 static inline void mt6577_auxadc_mod_reg(void __iomem *reg,
 					 u32 or_mask, u32 and_mask)
 {
 	u32 val;

 	val = readl(reg);
 	val |= or_mask;
 	val &= ~and_mask;
 	writel(val, reg);
 }

 static int mt6577_auxadc_read(struct iio_dev *indio_dev,
 			      struct iio_chan_spec const *chan)
 {
 	u32 val;
 	void __iomem *reg_channel;
 	int ret;
 	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);

 	reg_channel = adc_dev->reg_base + MT6577_AUXADC_DAT0 +
 		      chan->channel * 0x04;

 	mutex_lock(&adc_dev->lock);

 	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
 			      0, 1 << chan->channel);

 	/* read channel and make sure old ready bit == 0 */
 	ret = readl_poll_timeout(reg_channel, val,
 				 ((val & MT6577_AUXADC_RDY0) == 0),
 				 MT6577_AUXADC_SLEEP_US,
 				 MT6577_AUXADC_TIMEOUT_US);
 	if (ret < 0) {
 		dev_err(indio_dev->dev.parent,
 			"wait for channel[%d] ready bit clear time out\n",
 			chan->channel);
 		goto err_timeout;
 	}

 	/* set bit to trigger sample */
 	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
 			      1 << chan->channel, 0);

 	/* we must delay here for hardware sample channel data */
 	udelay(MT6577_AUXADC_SAMPLE_READY_US);

 	/* check MTK_AUXADC_CON2 if auxadc is idle */
 	ret = readl_poll_timeout(adc_dev->reg_base + MT6577_AUXADC_CON2, val,
 				 ((val & MT6577_AUXADC_STA) == 0),
 				 MT6577_AUXADC_SLEEP_US,
 				 MT6577_AUXADC_TIMEOUT_US);
 	if (ret < 0) {
 		dev_err(indio_dev->dev.parent,
 			"wait for auxadc idle time out\n");
 		goto err_timeout;
 	}

 	/* read channel and make sure ready bit == 1 */
 	ret = readl_poll_timeout(reg_channel, val,
 				 ((val & MT6577_AUXADC_RDY0) != 0),
 				 MT6577_AUXADC_SLEEP_US,
 				 MT6577_AUXADC_TIMEOUT_US);
 	if (ret < 0) {
 		dev_err(indio_dev->dev.parent,
 			"wait for channel[%d] data ready time out\n",
 			chan->channel);
 		goto err_timeout;
 	}

 	/* read data */
 	val = readl(reg_channel) & MT6577_AUXADC_DAT_MASK;

 	mutex_unlock(&adc_dev->lock);

 	return val;

 err_timeout:

 	mutex_unlock(&adc_dev->lock);

 	return -ETIMEDOUT;
 }

 static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev,
 				  struct iio_chan_spec const *chan,
 				  int *val,
 				  int *val2,
 				  long info)
 {
 	switch (info) {
 	case IIO_CHAN_INFO_PROCESSED:
 		*val = mt6577_auxadc_read(indio_dev, chan);
 		if (*val < 0) {
 			dev_err(indio_dev->dev.parent,
 				"failed to sample data on channel[%d]\n",
 				chan->channel);
 			return *val;
 		}
 		return IIO_VAL_INT;

 	default:
 		return -EINVAL;
 	}
 }

 static const struct iio_info mt6577_auxadc_info = {
 	.driver_module = THIS_MODULE,
 	.read_raw = &mt6577_auxadc_read_raw,
 };

 static int mt6577_auxadc_probe(struct platform_device *pdev)
 {
 	struct mt6577_auxadc_device *adc_dev;
 	unsigned long adc_clk_rate;
 	struct resource *res;
 	struct iio_dev *indio_dev;
 	int ret;

 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
 	if (!indio_dev)
 		return -ENOMEM;

 	adc_dev = iio_priv(indio_dev);
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->name = dev_name(&pdev->dev);
 	indio_dev->info = &mt6577_auxadc_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = mt6577_auxadc_iio_channels;
 	indio_dev->num_channels = ARRAY_SIZE(mt6577_auxadc_iio_channels);

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(adc_dev->reg_base)) {
 		dev_err(&pdev->dev, "failed to get auxadc base address\n");
 		return PTR_ERR(adc_dev->reg_base);
 	}

 	adc_dev->adc_clk = devm_clk_get(&pdev->dev, "main");
 	if (IS_ERR(adc_dev->adc_clk)) {
 		dev_err(&pdev->dev, "failed to get auxadc clock\n");
 		return PTR_ERR(adc_dev->adc_clk);
 	}

 	ret = clk_prepare_enable(adc_dev->adc_clk);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to enable auxadc clock\n");
 		return ret;
 	}

 	adc_clk_rate = clk_get_rate(adc_dev->adc_clk);
 	if (!adc_clk_rate) {
 		ret = -EINVAL;
 		dev_err(&pdev->dev, "null clock rate\n");
 		goto err_disable_clk;
 	}

 	mutex_init(&adc_dev->lock);

 	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
 			      MT6577_AUXADC_PDN_EN, 0);
 	mdelay(MT6577_AUXADC_POWER_READY_MS);

 	platform_set_drvdata(pdev, indio_dev);

 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to register iio device\n");
 		goto err_power_off;
 	}

 	return 0;

 err_power_off:
 	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
 			      0, MT6577_AUXADC_PDN_EN);
 err_disable_clk:
 	clk_disable_unprepare(adc_dev->adc_clk);
 	return ret;
 }

 static int mt6577_auxadc_remove(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);

 	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
 			      0, MT6577_AUXADC_PDN_EN);

 	clk_disable_unprepare(adc_dev->adc_clk);

 	return 0;
 }

 static const struct of_device_id mt6577_auxadc_of_match[] = {
 	{ .compatible = "mediatek,mt2701-auxadc", },
 	{ .compatible = "mediatek,mt8173-auxadc", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, mt6577_auxadc_of_match);

 static struct platform_driver mt6577_auxadc_driver = {
 	.driver = {
 		.name   = "mt6577-auxadc",
 		.of_match_table = mt6577_auxadc_of_match,
 	},
 	.probe	= mt6577_auxadc_probe,
 	.remove	= mt6577_auxadc_remove,
 };
 module_platform_driver(mt6577_auxadc_driver);

 MODULE_AUTHOR("Zhiyong Tao <zhiyong.tao@mediatek.com>");
 MODULE_DESCRIPTION("MTK AUXADC Device Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (c) 2016 MediaTek Inc.
	* Author: Zhiyong Tao <zhiyong.tao@mediatek.com>
	*
	* 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.
	*/

	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/platform_device.h>
	#include <linux/iopoll.h>
	#include <linux/io.h>
	#include <linux/iio/iio.h>

	/* Register definitions */
	#define MT6577_AUXADC_CON0 0x00
	#define MT6577_AUXADC_CON1 0x04
	#define MT6577_AUXADC_CON2 0x10
	#define MT6577_AUXADC_STA BIT(0)

	#define MT6577_AUXADC_DAT0 0x14
	#define MT6577_AUXADC_RDY0 BIT(12)

	#define MT6577_AUXADC_MISC 0x94
	#define MT6577_AUXADC_PDN_EN BIT(14)

	#define MT6577_AUXADC_DAT_MASK 0xfff
	#define MT6577_AUXADC_SLEEP_US 1000
	#define MT6577_AUXADC_TIMEOUT_US 10000
	#define MT6577_AUXADC_POWER_READY_MS 1
	#define MT6577_AUXADC_SAMPLE_READY_US 25

	struct mt6577_auxadc_device {
	void __iomem *reg_base;
	struct clk *adc_clk;
	struct mutex lock;
	};

	#define MT6577_AUXADC_CHANNEL(idx) { \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.channel = (idx), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
	}

	static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = {
	MT6577_AUXADC_CHANNEL(0),
	MT6577_AUXADC_CHANNEL(1),
	MT6577_AUXADC_CHANNEL(2),
	MT6577_AUXADC_CHANNEL(3),
	MT6577_AUXADC_CHANNEL(4),
	MT6577_AUXADC_CHANNEL(5),
	MT6577_AUXADC_CHANNEL(6),
	MT6577_AUXADC_CHANNEL(7),
	MT6577_AUXADC_CHANNEL(8),
	MT6577_AUXADC_CHANNEL(9),
	MT6577_AUXADC_CHANNEL(10),
	MT6577_AUXADC_CHANNEL(11),
	MT6577_AUXADC_CHANNEL(12),
	MT6577_AUXADC_CHANNEL(13),
	MT6577_AUXADC_CHANNEL(14),
	MT6577_AUXADC_CHANNEL(15),
	};

	static inline void mt6577_auxadc_mod_reg(void __iomem *reg,
	u32 or_mask, u32 and_mask)
	{
	u32 val;

	val = readl(reg);
	val \|= or_mask;
	val &= ~and_mask;
	writel(val, reg);
	}

	static int mt6577_auxadc_read(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan)
	{
	u32 val;
	void __iomem *reg_channel;
	int ret;
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);

	reg_channel = adc_dev->reg_base + MT6577_AUXADC_DAT0 +
	chan->channel * 0x04;

	mutex_lock(&adc_dev->lock);

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
	0, 1 << chan->channel);

	/* read channel and make sure old ready bit == 0 */
	ret = readl_poll_timeout(reg_channel, val,
	((val & MT6577_AUXADC_RDY0) == 0),
	MT6577_AUXADC_SLEEP_US,
	MT6577_AUXADC_TIMEOUT_US);
	if (ret < 0) {
	dev_err(indio_dev->dev.parent,
	"wait for channel[%d] ready bit clear time out\n",
	chan->channel);
	goto err_timeout;
	}

	/* set bit to trigger sample */
	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
	1 << chan->channel, 0);

	/* we must delay here for hardware sample channel data */
	udelay(MT6577_AUXADC_SAMPLE_READY_US);

	/* check MTK_AUXADC_CON2 if auxadc is idle */
	ret = readl_poll_timeout(adc_dev->reg_base + MT6577_AUXADC_CON2, val,
	((val & MT6577_AUXADC_STA) == 0),
	MT6577_AUXADC_SLEEP_US,
	MT6577_AUXADC_TIMEOUT_US);
	if (ret < 0) {
	dev_err(indio_dev->dev.parent,
	"wait for auxadc idle time out\n");
	goto err_timeout;
	}

	/* read channel and make sure ready bit == 1 */
	ret = readl_poll_timeout(reg_channel, val,
	((val & MT6577_AUXADC_RDY0) != 0),
	MT6577_AUXADC_SLEEP_US,
	MT6577_AUXADC_TIMEOUT_US);
	if (ret < 0) {
	dev_err(indio_dev->dev.parent,
	"wait for channel[%d] data ready time out\n",
	chan->channel);
	goto err_timeout;
	}

	/* read data */
	val = readl(reg_channel) & MT6577_AUXADC_DAT_MASK;

	mutex_unlock(&adc_dev->lock);

	return val;

	err_timeout:

	mutex_unlock(&adc_dev->lock);

	return -ETIMEDOUT;
	}

	static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int *val,
	int *val2,
	long info)
	{
	switch (info) {
	case IIO_CHAN_INFO_PROCESSED:
	*val = mt6577_auxadc_read(indio_dev, chan);
	if (*val < 0) {
	dev_err(indio_dev->dev.parent,
	"failed to sample data on channel[%d]\n",
	chan->channel);
	return *val;
	}
	return IIO_VAL_INT;

	default:
	return -EINVAL;
	}
	}

	static const struct iio_info mt6577_auxadc_info = {
	.driver_module = THIS_MODULE,
	.read_raw = &mt6577_auxadc_read_raw,
	};

	static int mt6577_auxadc_probe(struct platform_device *pdev)
	{
	struct mt6577_auxadc_device *adc_dev;
	unsigned long adc_clk_rate;
	struct resource *res;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
	if (!indio_dev)
	return -ENOMEM;

	adc_dev = iio_priv(indio_dev);
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->name = dev_name(&pdev->dev);
	indio_dev->info = &mt6577_auxadc_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mt6577_auxadc_iio_channels;
	indio_dev->num_channels = ARRAY_SIZE(mt6577_auxadc_iio_channels);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(adc_dev->reg_base)) {
	dev_err(&pdev->dev, "failed to get auxadc base address\n");
	return PTR_ERR(adc_dev->reg_base);
	}

	adc_dev->adc_clk = devm_clk_get(&pdev->dev, "main");
	if (IS_ERR(adc_dev->adc_clk)) {
	dev_err(&pdev->dev, "failed to get auxadc clock\n");
	return PTR_ERR(adc_dev->adc_clk);
	}

	ret = clk_prepare_enable(adc_dev->adc_clk);
	if (ret) {
	dev_err(&pdev->dev, "failed to enable auxadc clock\n");
	return ret;
	}

	adc_clk_rate = clk_get_rate(adc_dev->adc_clk);
	if (!adc_clk_rate) {
	ret = -EINVAL;
	dev_err(&pdev->dev, "null clock rate\n");
	goto err_disable_clk;
	}

	mutex_init(&adc_dev->lock);

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
	MT6577_AUXADC_PDN_EN, 0);
	mdelay(MT6577_AUXADC_POWER_READY_MS);

	platform_set_drvdata(pdev, indio_dev);

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
	dev_err(&pdev->dev, "failed to register iio device\n");
	goto err_power_off;
	}

	return 0;

	err_power_off:
	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
	0, MT6577_AUXADC_PDN_EN);
	err_disable_clk:
	clk_disable_unprepare(adc_dev->adc_clk);
	return ret;
	}

	static int mt6577_auxadc_remove(struct platform_device *pdev)
	{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
	0, MT6577_AUXADC_PDN_EN);

	clk_disable_unprepare(adc_dev->adc_clk);

	return 0;
	}

	static const struct of_device_id mt6577_auxadc_of_match[] = {
	{ .compatible = "mediatek,mt2701-auxadc", },
	{ .compatible = "mediatek,mt8173-auxadc", },
	{ }
	};
	MODULE_DEVICE_TABLE(of, mt6577_auxadc_of_match);

	static struct platform_driver mt6577_auxadc_driver = {
	.driver = {
	.name = "mt6577-auxadc",
	.of_match_table = mt6577_auxadc_of_match,
	},
	.probe = mt6577_auxadc_probe,
	.remove = mt6577_auxadc_remove,
	};
	module_platform_driver(mt6577_auxadc_driver);

	MODULE_AUTHOR("Zhiyong Tao <zhiyong.tao@mediatek.com>");
	MODULE_DESCRIPTION("MTK AUXADC Device Driver");
	MODULE_LICENSE("GPL v2");