298 lines
6.9 KiB
C
298 lines
6.9 KiB
C
/*
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* Freescale Vybrid vf610 DAC driver
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*
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* Copyright 2016 Toradex AG
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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/err.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#include <linux/slab.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#define VF610_DACx_STATCTRL 0x20
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#define VF610_DAC_DACEN BIT(15)
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#define VF610_DAC_DACRFS BIT(14)
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#define VF610_DAC_LPEN BIT(11)
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#define VF610_DAC_DAT0(x) ((x) & 0xFFF)
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enum vf610_conversion_mode_sel {
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VF610_DAC_CONV_HIGH_POWER,
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VF610_DAC_CONV_LOW_POWER,
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};
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struct vf610_dac {
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struct clk *clk;
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struct device *dev;
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enum vf610_conversion_mode_sel conv_mode;
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void __iomem *regs;
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};
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static void vf610_dac_init(struct vf610_dac *info)
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{
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int val;
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info->conv_mode = VF610_DAC_CONV_LOW_POWER;
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val = VF610_DAC_DACEN | VF610_DAC_DACRFS |
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VF610_DAC_LPEN;
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writel(val, info->regs + VF610_DACx_STATCTRL);
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}
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static void vf610_dac_exit(struct vf610_dac *info)
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{
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int val;
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val = readl(info->regs + VF610_DACx_STATCTRL);
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val &= ~VF610_DAC_DACEN;
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writel(val, info->regs + VF610_DACx_STATCTRL);
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}
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static int vf610_set_conversion_mode(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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unsigned int mode)
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{
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struct vf610_dac *info = iio_priv(indio_dev);
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int val;
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mutex_lock(&indio_dev->mlock);
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info->conv_mode = mode;
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val = readl(info->regs + VF610_DACx_STATCTRL);
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if (mode)
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val |= VF610_DAC_LPEN;
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else
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val &= ~VF610_DAC_LPEN;
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writel(val, info->regs + VF610_DACx_STATCTRL);
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mutex_unlock(&indio_dev->mlock);
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return 0;
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}
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static int vf610_get_conversion_mode(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan)
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{
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struct vf610_dac *info = iio_priv(indio_dev);
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return info->conv_mode;
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}
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static const char * const vf610_conv_modes[] = { "high-power", "low-power" };
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static const struct iio_enum vf610_conversion_mode = {
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.items = vf610_conv_modes,
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.num_items = ARRAY_SIZE(vf610_conv_modes),
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.get = vf610_get_conversion_mode,
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.set = vf610_set_conversion_mode,
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};
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static const struct iio_chan_spec_ext_info vf610_ext_info[] = {
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IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR,
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&vf610_conversion_mode),
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{},
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};
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#define VF610_DAC_CHAN(_chan_type) { \
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.type = (_chan_type), \
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.output = 1, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.ext_info = vf610_ext_info, \
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}
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static const struct iio_chan_spec vf610_dac_iio_channels[] = {
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VF610_DAC_CHAN(IIO_VOLTAGE),
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};
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static int vf610_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2,
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long mask)
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{
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struct vf610_dac *info = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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*val = VF610_DAC_DAT0(readl(info->regs));
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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/*
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* DACRFS is always 1 for valid reference and typical
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* reference voltage as per Vybrid datasheet is 3.3V
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* from section 9.1.2.1 of Vybrid datasheet
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*/
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*val = 3300 /* mV */;
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*val2 = 12;
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return IIO_VAL_FRACTIONAL_LOG2;
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default:
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return -EINVAL;
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}
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}
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static int vf610_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2,
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long mask)
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{
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struct vf610_dac *info = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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mutex_lock(&indio_dev->mlock);
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writel(VF610_DAC_DAT0(val), info->regs);
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mutex_unlock(&indio_dev->mlock);
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return 0;
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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 vf610_dac_iio_info = {
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.read_raw = &vf610_read_raw,
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.write_raw = &vf610_write_raw,
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};
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static const struct of_device_id vf610_dac_match[] = {
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{ .compatible = "fsl,vf610-dac", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, vf610_dac_match);
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static int vf610_dac_probe(struct platform_device *pdev)
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{
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struct iio_dev *indio_dev;
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struct vf610_dac *info;
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struct resource *mem;
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int ret;
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indio_dev = devm_iio_device_alloc(&pdev->dev,
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sizeof(struct vf610_dac));
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if (!indio_dev) {
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dev_err(&pdev->dev, "Failed allocating iio device\n");
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return -ENOMEM;
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}
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info = iio_priv(indio_dev);
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info->dev = &pdev->dev;
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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info->regs = devm_ioremap_resource(&pdev->dev, mem);
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if (IS_ERR(info->regs))
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return PTR_ERR(info->regs);
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info->clk = devm_clk_get(&pdev->dev, "dac");
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if (IS_ERR(info->clk)) {
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dev_err(&pdev->dev, "Failed getting clock, err = %ld\n",
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PTR_ERR(info->clk));
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return PTR_ERR(info->clk);
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}
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platform_set_drvdata(pdev, indio_dev);
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indio_dev->name = dev_name(&pdev->dev);
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indio_dev->dev.parent = &pdev->dev;
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indio_dev->dev.of_node = pdev->dev.of_node;
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indio_dev->info = &vf610_dac_iio_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = vf610_dac_iio_channels;
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indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);
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ret = clk_prepare_enable(info->clk);
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if (ret) {
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dev_err(&pdev->dev,
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"Could not prepare or enable the clock\n");
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return ret;
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}
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vf610_dac_init(info);
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ret = iio_device_register(indio_dev);
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if (ret) {
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dev_err(&pdev->dev, "Couldn't register the device\n");
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goto error_iio_device_register;
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}
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return 0;
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error_iio_device_register:
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clk_disable_unprepare(info->clk);
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return ret;
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}
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static int vf610_dac_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 vf610_dac *info = iio_priv(indio_dev);
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iio_device_unregister(indio_dev);
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vf610_dac_exit(info);
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clk_disable_unprepare(info->clk);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int vf610_dac_suspend(struct device *dev)
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{
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struct iio_dev *indio_dev = dev_get_drvdata(dev);
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struct vf610_dac *info = iio_priv(indio_dev);
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vf610_dac_exit(info);
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clk_disable_unprepare(info->clk);
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return 0;
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}
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static int vf610_dac_resume(struct device *dev)
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{
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struct iio_dev *indio_dev = dev_get_drvdata(dev);
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struct vf610_dac *info = iio_priv(indio_dev);
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int ret;
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ret = clk_prepare_enable(info->clk);
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if (ret)
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return ret;
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vf610_dac_init(info);
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return 0;
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}
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#endif
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static SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend, vf610_dac_resume);
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static struct platform_driver vf610_dac_driver = {
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.probe = vf610_dac_probe,
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.remove = vf610_dac_remove,
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.driver = {
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.name = "vf610-dac",
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.of_match_table = vf610_dac_match,
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.pm = &vf610_dac_pm_ops,
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},
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};
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module_platform_driver(vf610_dac_driver);
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MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@toradex.com>");
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MODULE_DESCRIPTION("Freescale VF610 DAC driver");
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MODULE_LICENSE("GPL v2");
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