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