android/drivers/iio/adc/mt6577_auxadc.c

/*
 * 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/proc_fs.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_CON1_SET                0x08
#define MT6577_AUXADC_CON1_CLR                0x0C
#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 mtk_auxadc_compatible {
	bool sample_data_cali;
	bool check_global_idle;
};

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

static const struct mtk_auxadc_compatible mt8173_compat = {
	.sample_data_cali = false,
	.check_global_idle = true,
};

static const struct mtk_auxadc_compatible mt6768_compat = {
	.sample_data_cali = true,
	.check_global_idle = false,
};

#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),
};

/* For calibration */
#define ADC_GE_OE_MASK          0x000003ff
#define ADC_GE_OE_EN_MASK       0x00000001

struct adc_cali_info {
	u32 efuse_en_bs;        /* dt efuse en bit shift */
	u32 efuse_ge_bs;        /* dt efuse ge bit shift */
	u32 efuse_oe_bs;        /* dt efuse oe bit shift */
	u32 efuse_idx;          /* dt efuse index */
	u32 efuse_reg_value;    /* efuse reg value */
	u32 efuse_en;           /* efuse en value */
	u32 efuse_ge;           /* efuse ge value */
	u32 efuse_oe;           /* efuse oe value */
	s32 cali_ge;            /* cali ge value */
	s32 cali_oe;            /* cali oe value */
	u32 gain;               /* gain value */
};

static struct adc_cali_info adc_cali;

extern u32 __attribute__((weak)) get_devinfo_with_index(u32 index)
{
	return 0;
}

static void mt_auxadc_update_cali(struct device *dev)
{
	struct device_node *np = dev->of_node;
	u32 reg;
	int ret = 0;

	if (np) {
		ret = of_property_read_u32(np, "mediatek,cali-en-bit",
			&adc_cali.efuse_en_bs);
		if (ret == 0)
			pr_info("find node mediatek,cali-en-bit:%d\n",
				adc_cali.efuse_en_bs);
		else
			return;

		ret = of_property_read_u32(np, "mediatek,cali-ge-bit",
			&adc_cali.efuse_ge_bs);
		if (ret == 0)
			pr_info("find node mediatek,cali-ge-bit:%d\n",
				adc_cali.efuse_ge_bs);
		else
			return;

		ret = of_property_read_u32(np, "mediatek,cali-oe-bit",
			&adc_cali.efuse_oe_bs);
		if (ret == 0)
			pr_info("find node mediatek,cali-oe-bit:%d\n",
				adc_cali.efuse_oe_bs);
		else
			return;

		ret = of_property_read_u32(np, "mediatek,cali-efuse-index",
			&adc_cali.efuse_idx);
		if (ret == 0)
			pr_info("find node mediatek,cali-efuse-index:%d\n",
				adc_cali.efuse_idx);
		else
			return;

		reg = get_devinfo_with_index(adc_cali.efuse_idx);
		adc_cali.efuse_reg_value = reg;

		adc_cali.efuse_en = (reg >> adc_cali.efuse_en_bs) &
			ADC_GE_OE_EN_MASK;

		if (adc_cali.efuse_en) {
			adc_cali.efuse_oe =
				(reg >> adc_cali.efuse_oe_bs) & ADC_GE_OE_MASK;
			adc_cali.efuse_ge =
				(reg >> adc_cali.efuse_ge_bs) & ADC_GE_OE_MASK;

			/* In sw implement guide, ge should div 4096.
			 * But we don't do that now due to it
			 * will multi 4096 later
			 */
			adc_cali.cali_ge = adc_cali.efuse_ge - 512;
			adc_cali.cali_oe = adc_cali.efuse_oe - 512;
			adc_cali.gain = 1 + adc_cali.cali_ge;
			/* In sw implement guide, gain = 1 + GE =
			 * 1 + cali_ge / 4096,
			 * we doen't use the variable here
			 */
		}
	}
}

static int mt_auxadc_get_cali_data(unsigned int rawdata, bool enable_cali)
{
	unsigned int data;

	/* In sw implement guide, 4096 * gain = 4096 * (1 + GE)
	 * = 4096 * (1 + cali_ge / 4096) = 4096 + cali_ge)
	 */
	if (enable_cali)
		data = (4096 * (rawdata - adc_cali.cali_oe)) /
			(4096 + adc_cali.cali_ge);
	else
		data = rawdata;

	return data;
}

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);

	writel(1 << chan->channel, adc_dev->reg_base + MT6577_AUXADC_CON1_CLR);

	/* 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 */
	writel(1 << chan->channel, adc_dev->reg_base + MT6577_AUXADC_CON1_SET);

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

	if (adc_dev->dev_comp->check_global_idle) {
		/* 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)
{
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);
	int raw_val;

	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;
		}
		raw_val = *val;
		if (adc_dev->dev_comp->sample_data_cali)
			*val = mt_auxadc_get_cali_data(*val, true);

		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 __maybe_unused mt6577_auxadc_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);
	int ret;

	ret = clk_prepare_enable(adc_dev->adc_clk);
	if (ret) {
		pr_err("failed to enable auxadc clock\n");
		return ret;
	}

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

	return 0;
}

static int __maybe_unused mt6577_auxadc_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct mt6577_auxadc_device *adc_dev = iio_priv(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 int proc_utilization_show(struct seq_file *m, void *v)
{
	int raw, raw_cali;

	seq_puts(m, "********** Auxadc status dump **********\n");

	seq_printf(m, "ADC_CALI_EN_MASK:0x%x ADC_CALI_EN_SHIFT:%d\n",
		ADC_GE_OE_EN_MASK, adc_cali.efuse_en_bs);
	seq_printf(m, "ADC_GE_MASK:0x%x ADC_GE_SHIFT:%d\n",
		ADC_GE_OE_MASK, adc_cali.efuse_ge_bs);
	seq_printf(m, "ADC_OE_MASK:0x%x ADC_OE_SHIFT:%d\n",
		ADC_GE_OE_MASK, adc_cali.efuse_oe_bs);

	seq_printf(m, "reg_value=0x%x efuse_en=%d, efuse_ge=%d, efuse_oe=%d\n",
		adc_cali.efuse_reg_value, adc_cali.efuse_en,
		adc_cali.efuse_ge, adc_cali.efuse_oe);

	seq_printf(m, "cali_ge:%d cali_oe:%d gain:0x%x\n",
		adc_cali.cali_ge, adc_cali.cali_oe, adc_cali.gain);

	for (raw = 100; raw <= 4500; raw = raw + 100) {
		raw_cali = mt_auxadc_get_cali_data(raw, true);

		seq_printf(m, "raw without cali : %d, with cali : %d\n",
			raw, raw_cali);
	}

	return 0;
}

static int proc_utilization_open(struct inode *inode, struct file *file)
{
	return single_open(file, proc_utilization_show, NULL);
}

static const struct file_operations auxadc_debug_proc_fops = {
	.open = proc_utilization_open,
	.read = seq_read,
};

static void adc_debug_init(void)
{
	struct proc_dir_entry *mt_auxadc_dir;

	mt_auxadc_dir = proc_mkdir("mt-auxadc", NULL);
	if (!mt_auxadc_dir) {
		pr_debug("fail to mkdir /proc/mt-auxadc\n");
		return;
	}
	proc_create("dump_auxadc_status", 0644, mt_auxadc_dir,
		&auxadc_debug_proc_fops);
	pr_debug("proc_create auxadc_debug_proc_fops\n");
}

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;
	}

	adc_dev->dev_comp = of_device_get_match_data(&pdev->dev);
	if (!adc_dev->dev_comp) {
		ret = -EINVAL;
		dev_err(&pdev->dev, "null dev_comp\n");
		goto err_disable_clk;
	}

	if (adc_dev->dev_comp->sample_data_cali)
		mt_auxadc_update_cali(&pdev->dev);

	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;
	}

	adc_debug_init();

	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 dev_pm_ops mt6577_auxadc_pm_ops = {
	SET_LATE_SYSTEM_SLEEP_PM_OPS(mt6577_auxadc_suspend,
		mt6577_auxadc_resume)
};

static const struct of_device_id mt6577_auxadc_of_match[] = {
	{ .compatible = "mediatek,mt2701-auxadc", .data = &mt8173_compat},
	{ .compatible = "mediatek,mt7622-auxadc", .data = &mt8173_compat},
	{ .compatible = "mediatek,mt8173-auxadc", .data = &mt8173_compat},
	{ .compatible = "mediatek,mt6768-auxadc", .data = &mt6768_compat},
	{ }
};
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,
		.pm = &mt6577_auxadc_pm_ops,
	},
	.probe	= mt6577_auxadc_probe,
	.remove	= mt6577_auxadc_remove,
};

static int __init mt6577_auxadc_init(void)
{
	return platform_driver_register(&mt6577_auxadc_driver);
}

static void __exit mt6577_auxadc_exit(void)
{
	platform_driver_unregister(&mt6577_auxadc_driver);
}

subsys_initcall(mt6577_auxadc_init);
module_exit(mt6577_auxadc_exit);

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