292 lines
7.6 KiB
C
292 lines
7.6 KiB
C
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/*
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* Copyright (c) 2016 MediaTek Inc.
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* Author: Zhiyong Tao <zhiyong.tao@mediatek.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/iopoll.h>
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#include <linux/io.h>
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#include <linux/iio/iio.h>
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/* Register definitions */
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#define MT6577_AUXADC_CON0 0x00
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#define MT6577_AUXADC_CON1 0x04
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#define MT6577_AUXADC_CON2 0x10
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#define MT6577_AUXADC_STA BIT(0)
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#define MT6577_AUXADC_DAT0 0x14
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#define MT6577_AUXADC_RDY0 BIT(12)
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#define MT6577_AUXADC_MISC 0x94
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#define MT6577_AUXADC_PDN_EN BIT(14)
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#define MT6577_AUXADC_DAT_MASK 0xfff
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#define MT6577_AUXADC_SLEEP_US 1000
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#define MT6577_AUXADC_TIMEOUT_US 10000
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#define MT6577_AUXADC_POWER_READY_MS 1
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#define MT6577_AUXADC_SAMPLE_READY_US 25
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struct mt6577_auxadc_device {
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void __iomem *reg_base;
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struct clk *adc_clk;
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struct mutex lock;
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};
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#define MT6577_AUXADC_CHANNEL(idx) { \
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.type = IIO_VOLTAGE, \
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.indexed = 1, \
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.channel = (idx), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
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}
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static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = {
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MT6577_AUXADC_CHANNEL(0),
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MT6577_AUXADC_CHANNEL(1),
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MT6577_AUXADC_CHANNEL(2),
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MT6577_AUXADC_CHANNEL(3),
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MT6577_AUXADC_CHANNEL(4),
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MT6577_AUXADC_CHANNEL(5),
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MT6577_AUXADC_CHANNEL(6),
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MT6577_AUXADC_CHANNEL(7),
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MT6577_AUXADC_CHANNEL(8),
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MT6577_AUXADC_CHANNEL(9),
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MT6577_AUXADC_CHANNEL(10),
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MT6577_AUXADC_CHANNEL(11),
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MT6577_AUXADC_CHANNEL(12),
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MT6577_AUXADC_CHANNEL(13),
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MT6577_AUXADC_CHANNEL(14),
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MT6577_AUXADC_CHANNEL(15),
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};
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static inline void mt6577_auxadc_mod_reg(void __iomem *reg,
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u32 or_mask, u32 and_mask)
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{
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u32 val;
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val = readl(reg);
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val |= or_mask;
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val &= ~and_mask;
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writel(val, reg);
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}
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static int mt6577_auxadc_read(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan)
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{
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u32 val;
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void __iomem *reg_channel;
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int ret;
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struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);
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reg_channel = adc_dev->reg_base + MT6577_AUXADC_DAT0 +
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chan->channel * 0x04;
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mutex_lock(&adc_dev->lock);
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mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
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0, 1 << chan->channel);
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/* read channel and make sure old ready bit == 0 */
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ret = readl_poll_timeout(reg_channel, val,
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((val & MT6577_AUXADC_RDY0) == 0),
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MT6577_AUXADC_SLEEP_US,
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MT6577_AUXADC_TIMEOUT_US);
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if (ret < 0) {
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dev_err(indio_dev->dev.parent,
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"wait for channel[%d] ready bit clear time out\n",
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chan->channel);
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goto err_timeout;
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}
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/* set bit to trigger sample */
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mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
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1 << chan->channel, 0);
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/* we must delay here for hardware sample channel data */
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udelay(MT6577_AUXADC_SAMPLE_READY_US);
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/* check MTK_AUXADC_CON2 if auxadc is idle */
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ret = readl_poll_timeout(adc_dev->reg_base + MT6577_AUXADC_CON2, val,
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((val & MT6577_AUXADC_STA) == 0),
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MT6577_AUXADC_SLEEP_US,
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MT6577_AUXADC_TIMEOUT_US);
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if (ret < 0) {
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dev_err(indio_dev->dev.parent,
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"wait for auxadc idle time out\n");
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goto err_timeout;
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}
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/* read channel and make sure ready bit == 1 */
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ret = readl_poll_timeout(reg_channel, val,
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((val & MT6577_AUXADC_RDY0) != 0),
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MT6577_AUXADC_SLEEP_US,
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MT6577_AUXADC_TIMEOUT_US);
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if (ret < 0) {
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dev_err(indio_dev->dev.parent,
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"wait for channel[%d] data ready time out\n",
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chan->channel);
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goto err_timeout;
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}
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/* read data */
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val = readl(reg_channel) & MT6577_AUXADC_DAT_MASK;
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mutex_unlock(&adc_dev->lock);
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return val;
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err_timeout:
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mutex_unlock(&adc_dev->lock);
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return -ETIMEDOUT;
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}
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static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val,
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int *val2,
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long info)
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{
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switch (info) {
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case IIO_CHAN_INFO_PROCESSED:
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*val = mt6577_auxadc_read(indio_dev, chan);
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if (*val < 0) {
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dev_err(indio_dev->dev.parent,
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"failed to sample data on channel[%d]\n",
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chan->channel);
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return *val;
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}
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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}
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static const struct iio_info mt6577_auxadc_info = {
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.driver_module = THIS_MODULE,
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.read_raw = &mt6577_auxadc_read_raw,
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};
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static int mt6577_auxadc_probe(struct platform_device *pdev)
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{
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struct mt6577_auxadc_device *adc_dev;
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unsigned long adc_clk_rate;
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struct resource *res;
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struct iio_dev *indio_dev;
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int ret;
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indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
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if (!indio_dev)
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return -ENOMEM;
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adc_dev = iio_priv(indio_dev);
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indio_dev->dev.parent = &pdev->dev;
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indio_dev->name = dev_name(&pdev->dev);
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indio_dev->info = &mt6577_auxadc_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = mt6577_auxadc_iio_channels;
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indio_dev->num_channels = ARRAY_SIZE(mt6577_auxadc_iio_channels);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(adc_dev->reg_base)) {
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dev_err(&pdev->dev, "failed to get auxadc base address\n");
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return PTR_ERR(adc_dev->reg_base);
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}
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adc_dev->adc_clk = devm_clk_get(&pdev->dev, "main");
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if (IS_ERR(adc_dev->adc_clk)) {
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dev_err(&pdev->dev, "failed to get auxadc clock\n");
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return PTR_ERR(adc_dev->adc_clk);
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}
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ret = clk_prepare_enable(adc_dev->adc_clk);
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if (ret) {
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dev_err(&pdev->dev, "failed to enable auxadc clock\n");
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return ret;
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}
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adc_clk_rate = clk_get_rate(adc_dev->adc_clk);
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if (!adc_clk_rate) {
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ret = -EINVAL;
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dev_err(&pdev->dev, "null clock rate\n");
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goto err_disable_clk;
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}
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mutex_init(&adc_dev->lock);
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mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
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MT6577_AUXADC_PDN_EN, 0);
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mdelay(MT6577_AUXADC_POWER_READY_MS);
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platform_set_drvdata(pdev, indio_dev);
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ret = iio_device_register(indio_dev);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to register iio device\n");
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goto err_power_off;
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}
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return 0;
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err_power_off:
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mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
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0, MT6577_AUXADC_PDN_EN);
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err_disable_clk:
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clk_disable_unprepare(adc_dev->adc_clk);
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return ret;
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}
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static int mt6577_auxadc_remove(struct platform_device *pdev)
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{
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struct iio_dev *indio_dev = platform_get_drvdata(pdev);
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struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
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0, MT6577_AUXADC_PDN_EN);
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clk_disable_unprepare(adc_dev->adc_clk);
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return 0;
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}
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static const struct of_device_id mt6577_auxadc_of_match[] = {
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{ .compatible = "mediatek,mt2701-auxadc", },
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{ .compatible = "mediatek,mt8173-auxadc", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, mt6577_auxadc_of_match);
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static struct platform_driver mt6577_auxadc_driver = {
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.driver = {
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.name = "mt6577-auxadc",
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.of_match_table = mt6577_auxadc_of_match,
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},
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.probe = mt6577_auxadc_probe,
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.remove = mt6577_auxadc_remove,
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};
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module_platform_driver(mt6577_auxadc_driver);
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MODULE_AUTHOR("Zhiyong Tao <zhiyong.tao@mediatek.com>");
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MODULE_DESCRIPTION("MTK AUXADC Device Driver");
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MODULE_LICENSE("GPL v2");
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