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Commit 1b983bf4 authored by Sanchayan Maity's avatar Sanchayan Maity Committed by Jonathan Cameron
Browse files

iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC 



Add driver support for DAC peripheral on Vybrid SoC.

Signed-off-by: default avatarSanchayan Maity <maitysanchayan@gmail.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 1961bce7

Documentation/ABI/testing/sysfs-bus-iio-vf610

+9 −0
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@@ -5,3 +5,12 @@ Description: 
		Specifies the hardware conversion mode used. The three

		available modes are "normal", "high-speed" and "low-power",

		where the last is the default mode.





What:		/sys/bus/iio/devices/iio:deviceX/out_conversion_mode

KernelVersion:	4.6

Contact:	linux-iio@vger.kernel.org

Description:

		Specifies the hardware conversion mode used within DAC.

		The two available modes are "high-power" and "low-power",

		where "low-power" mode is the default mode.

Documentation/devicetree/bindings/iio/dac/vf610-dac.txt

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Freescale vf610 Digital to Analog Converter bindings



The devicetree bindings are for the new DAC driver written for

vf610 SoCs from Freescale.



Required properties:

- compatible: Should contain "fsl,vf610-dac"

- reg: Offset and length of the register set for the device

- interrupts: Should contain the interrupt for the device

- clocks: The clock is needed by the DAC controller

- clock-names: Must contain "dac" matching entry in the clocks property.



Example:

dac0: dac@400cc000 {

	compatible = "fsl,vf610-dac";

	reg = <0x400cc000 0x1000>;

	interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;

	clock-names = "dac";

	clocks = <&clks VF610_CLK_DAC0>;

};

drivers/iio/dac/Kconfig

+10 −0
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@@ -217,4 +217,14 @@ config STX104 
	  addresses for the devices may be configured via the "base" module

	  parameter array.



config VF610_DAC

	tristate "Vybrid vf610 DAC driver"

	depends on OF

	depends on HAS_IOMEM

	help

	  Say yes here to support Vybrid board digital-to-analog converter.



	  This driver can also be built as a module. If so, the module will

	  be called vf610_dac.



endmenu

drivers/iio/dac/Makefile

+1 −0
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@@ -23,3 +23,4 @@ obj-$(CONFIG_MAX5821) += max5821.o 
obj-$(CONFIG_MCP4725) += mcp4725.o

obj-$(CONFIG_MCP4922) += mcp4922.o

obj-$(CONFIG_STX104) += stx104.o

obj-$(CONFIG_VF610_DAC) += vf610_dac.o

drivers/iio/dac/vf610_dac.c

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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 = {

	.driver_module = THIS_MODULE,

	.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");