Commit ead25133 authored by Ksenija Stanojevic's avatar Ksenija Stanojevic Committed by Lee Jones
Browse files

mfd: mxs-lradc: Add support for mxs-lradc 



Add core files for low resolution analog-to-digital converter (mxs-lradc)
MFD driver.

Signed-off-by: default avatarKsenija Stanojevic <ksenija.stanojevic@gmail.com>
Reviewed-by: default avatarMarek Vasut <marex@denx.de>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent c1ae3cfa

drivers/mfd/Kconfig

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@@ -344,6 +344,23 @@ config MFD_MC13XXX_I2C 
	help

	  Select this if your MC13xxx is connected via an I2C bus.



config MFD_MXS_LRADC

	tristate "Freescale i.MX23/i.MX28 LRADC"

	depends on ARCH_MXS || COMPILE_TEST

	select MFD_CORE

	select STMP_DEVICE

	help

	  Say yes here to build support for the Low Resolution

	  Analog-to-Digital Converter (LRADC) found on the i.MX23 and i.MX28

	  processors. This driver provides common support for accessing the

	  device, additional drivers must be enabled in order to use the

	  functionality of the device:

		mxs-lradc-adc for ADC readings

		mxs-lradc-ts  for touchscreen support



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

	  called mxs-lradc.



config MFD_MX25_TSADC

	tristate "Freescale i.MX25 integrated Touchscreen and ADC unit"

	select REGMAP_MMIO

drivers/mfd/Makefile

+1 −0
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@@ -215,3 +215,4 @@ obj-$(CONFIG_MFD_ALTERA_A10SR) += altera-a10sr.o 
obj-$(CONFIG_MFD_SUN4I_GPADC)	+= sun4i-gpadc.o



obj-$(CONFIG_MFD_STM32_TIMERS) 	+= stm32-timers.o

obj-$(CONFIG_MFD_MXS_LRADC)     += mxs-lradc.o

drivers/mfd/mxs-lradc.c

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/*

 * Freescale MXS Low Resolution Analog-to-Digital Converter driver

 *

 * Copyright (c) 2012 DENX Software Engineering, GmbH.

 * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>

 *

 * Authors:

 *  Marek Vasut <marex@denx.de>

 *  Ksenija Stanojevic <ksenija.stanojevic@gmail.com>

 *

 * 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/device.h>

#include <linux/mfd/core.h>

#include <linux/mfd/mxs-lradc.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

#include <linux/slab.h>



#define ADC_CELL		0

#define TSC_CELL		1

#define RES_MEM			0



enum mx23_lradc_irqs {

	MX23_LRADC_TS_IRQ = 0,

	MX23_LRADC_CH0_IRQ,

	MX23_LRADC_CH1_IRQ,

	MX23_LRADC_CH2_IRQ,

	MX23_LRADC_CH3_IRQ,

	MX23_LRADC_CH4_IRQ,

	MX23_LRADC_CH5_IRQ,

	MX23_LRADC_CH6_IRQ,

	MX23_LRADC_CH7_IRQ,

};



enum mx28_lradc_irqs {

	MX28_LRADC_TS_IRQ = 0,

	MX28_LRADC_TRESH0_IRQ,

	MX28_LRADC_TRESH1_IRQ,

	MX28_LRADC_CH0_IRQ,

	MX28_LRADC_CH1_IRQ,

	MX28_LRADC_CH2_IRQ,

	MX28_LRADC_CH3_IRQ,

	MX28_LRADC_CH4_IRQ,

	MX28_LRADC_CH5_IRQ,

	MX28_LRADC_CH6_IRQ,

	MX28_LRADC_CH7_IRQ,

	MX28_LRADC_BUTTON0_IRQ,

	MX28_LRADC_BUTTON1_IRQ,

};



static struct resource mx23_adc_resources[] = {

	DEFINE_RES_MEM(0x0, 0x0),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH0_IRQ, "mxs-lradc-channel0"),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH1_IRQ, "mxs-lradc-channel1"),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH2_IRQ, "mxs-lradc-channel2"),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH3_IRQ, "mxs-lradc-channel3"),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH4_IRQ, "mxs-lradc-channel4"),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH5_IRQ, "mxs-lradc-channel5"),

};



static struct resource mx23_touchscreen_resources[] = {

	DEFINE_RES_MEM(0x0, 0x0),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH6_IRQ, "mxs-lradc-channel6"),

	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH7_IRQ, "mxs-lradc-channel7"),

};



static struct resource mx28_adc_resources[] = {

	DEFINE_RES_MEM(0x0, 0x0),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH0_IRQ, "mxs-lradc-thresh0"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH1_IRQ, "mxs-lradc-thresh1"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH0_IRQ, "mxs-lradc-channel0"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH1_IRQ, "mxs-lradc-channel1"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH2_IRQ, "mxs-lradc-channel2"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH3_IRQ, "mxs-lradc-channel3"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH4_IRQ, "mxs-lradc-channel4"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH5_IRQ, "mxs-lradc-channel5"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON0_IRQ, "mxs-lradc-button0"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON1_IRQ, "mxs-lradc-button1"),

};



static struct resource mx28_touchscreen_resources[] = {

	DEFINE_RES_MEM(0x0, 0x0),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH6_IRQ, "mxs-lradc-channel6"),

	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH7_IRQ, "mxs-lradc-channel7"),

};



static struct mfd_cell mx23_cells[] = {

	{

		.name = "mxs-lradc-adc",

		.resources = mx23_adc_resources,

		.num_resources = ARRAY_SIZE(mx23_adc_resources),

	},

	{

		.name = "mxs-lradc-ts",

		.resources = mx23_touchscreen_resources,

		.num_resources = ARRAY_SIZE(mx23_touchscreen_resources),

	},

};



static struct mfd_cell mx28_cells[] = {

	{

		.name = "mxs-lradc-adc",

		.resources = mx28_adc_resources,

		.num_resources = ARRAY_SIZE(mx28_adc_resources),

	},

	{

		.name = "mxs-lradc-ts",

		.resources = mx28_touchscreen_resources,

		.num_resources = ARRAY_SIZE(mx28_touchscreen_resources),

	}

};



static const struct of_device_id mxs_lradc_dt_ids[] = {

	{ .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },

	{ .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);



static int mxs_lradc_probe(struct platform_device *pdev)

{

	const struct of_device_id *of_id;

	struct device *dev = &pdev->dev;

	struct device_node *node = dev->of_node;

	struct mxs_lradc *lradc;

	struct mfd_cell *cells = NULL;

	struct resource *res;

	int ret = 0;

	u32 ts_wires = 0;



	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);

	if (!lradc)

		return -ENOMEM;



	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);

	if (!of_id)

		return -EINVAL;



	lradc->soc = (enum mxs_lradc_id)of_id->data;



	lradc->clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(lradc->clk)) {

		dev_err(dev, "Failed to get the delay unit clock\n");

		return PTR_ERR(lradc->clk);

	}



	ret = clk_prepare_enable(lradc->clk);

	if (ret) {

		dev_err(dev, "Failed to enable the delay unit clock\n");

		return ret;

	}



	ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",

					 &ts_wires);



	if (!ret) {

		lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;



		switch (ts_wires) {

		case 4:

			lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE;

			break;

		case 5:

			if (lradc->soc == IMX28_LRADC) {

				lradc->touchscreen_wire =

					MXS_LRADC_TOUCHSCREEN_5WIRE;

				break;

			}

			/* fall through to an error message for i.MX23 */

		default:

			dev_err(&pdev->dev,

				"Unsupported number of touchscreen wires (%d)\n"

				, ts_wires);

			ret = -EINVAL;

			goto err_clk;

		}

	} else {

		lradc->buffer_vchans = BUFFER_VCHANS_ALL;

	}



	platform_set_drvdata(pdev, lradc);



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res)

		return -ENOMEM;



	switch (lradc->soc) {

	case IMX23_LRADC:

		mx23_adc_resources[RES_MEM] = *res;

		mx23_touchscreen_resources[RES_MEM] = *res;

		cells = mx23_cells;

		break;

	case IMX28_LRADC:

		mx28_adc_resources[RES_MEM] = *res;

		mx28_touchscreen_resources[RES_MEM] = *res;

		cells = mx28_cells;

		break;

	default:

		dev_err(dev, "Unsupported SoC\n");

		ret = -ENODEV;

		goto err_clk;

	}



	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,

				   &cells[ADC_CELL], 1, NULL, 0, NULL);

	if (ret) {

		dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");

		goto err_clk;

	}



	if (!lradc->touchscreen_wire)

		return 0;



	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,

				   &cells[TSC_CELL], 1, NULL, 0, NULL);

	if (ret) {

		dev_err(&pdev->dev,

			"Failed to add the touchscreen subdevice\n");

		goto err_clk;

	}



	return 0;



err_clk:

	clk_disable_unprepare(lradc->clk);



	return ret;

}



static int mxs_lradc_remove(struct platform_device *pdev)

{

	struct mxs_lradc *lradc = platform_get_drvdata(pdev);



	clk_disable_unprepare(lradc->clk);



	return 0;

}



static struct platform_driver mxs_lradc_driver = {

	.driver = {

		.name = "mxs-lradc",

		.of_match_table = mxs_lradc_dt_ids,

	},

	.probe = mxs_lradc_probe,

	.remove = mxs_lradc_remove,

};

module_platform_driver(mxs_lradc_driver);



MODULE_AUTHOR("Ksenija Stanojevic <ksenija.stanojevic@gmail.com>");

MODULE_DESCRIPTION("Freescale i.MX23/i.MX28 LRADC driver");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:mxs-lradc");

include/linux/mfd/mxs-lradc.h

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/*

 * Freescale MXS Low Resolution Analog-to-Digital Converter driver

 *

 * Copyright (c) 2012 DENX Software Engineering, GmbH.

 * Copyright (c) 2016 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>

 *

 * Author: Marek Vasut <marex@denx.de>

 *

 * 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.

 */



#ifndef __MFD_MXS_LRADC_H

#define __MFD_MXS_LRADC_H



#include <linux/bitops.h>

#include <linux/io.h>

#include <linux/stmp_device.h>



#define LRADC_MAX_DELAY_CHANS	4

#define LRADC_MAX_MAPPED_CHANS	8

#define LRADC_MAX_TOTAL_CHANS	16



#define LRADC_DELAY_TIMER_HZ	2000



#define LRADC_CTRL0				0x00

# define LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE	BIT(23)

# define LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE	BIT(22)

# define LRADC_CTRL0_MX28_YNNSW /* YM */	BIT(21)

# define LRADC_CTRL0_MX28_YPNSW /* YP */	BIT(20)

# define LRADC_CTRL0_MX28_YPPSW /* YP */	BIT(19)

# define LRADC_CTRL0_MX28_XNNSW /* XM */	BIT(18)

# define LRADC_CTRL0_MX28_XNPSW /* XM */	BIT(17)

# define LRADC_CTRL0_MX28_XPPSW /* XP */	BIT(16)



# define LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE	BIT(20)

# define LRADC_CTRL0_MX23_YM			BIT(19)

# define LRADC_CTRL0_MX23_XM			BIT(18)

# define LRADC_CTRL0_MX23_YP			BIT(17)

# define LRADC_CTRL0_MX23_XP			BIT(16)



# define LRADC_CTRL0_MX28_PLATE_MASK \

		(LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE | \

		LRADC_CTRL0_MX28_YNNSW | LRADC_CTRL0_MX28_YPNSW | \

		LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW | \

		LRADC_CTRL0_MX28_XNPSW | LRADC_CTRL0_MX28_XPPSW)



# define LRADC_CTRL0_MX23_PLATE_MASK \

		(LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE | \

		LRADC_CTRL0_MX23_YM | LRADC_CTRL0_MX23_XM | \

		LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XP)



#define LRADC_CTRL1				0x10

#define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN		BIT(24)

#define LRADC_CTRL1_LRADC_IRQ_EN(n)		(1 << ((n) + 16))

#define LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK	(0x1fff << 16)

#define LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK	(0x01ff << 16)

#define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET		16

#define LRADC_CTRL1_TOUCH_DETECT_IRQ		BIT(8)

#define LRADC_CTRL1_LRADC_IRQ(n)		BIT(n)

#define LRADC_CTRL1_MX28_LRADC_IRQ_MASK		0x1fff

#define LRADC_CTRL1_MX23_LRADC_IRQ_MASK		0x01ff

#define LRADC_CTRL1_LRADC_IRQ_OFFSET		0



#define LRADC_CTRL2				0x20

#define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET	24

#define LRADC_CTRL2_TEMPSENSE_PWD		BIT(15)



#define LRADC_STATUS				0x40

#define LRADC_STATUS_TOUCH_DETECT_RAW		BIT(0)



#define LRADC_CH(n)				(0x50 + (0x10 * (n)))

#define LRADC_CH_ACCUMULATE			BIT(29)

#define LRADC_CH_NUM_SAMPLES_MASK		(0x1f << 24)

#define LRADC_CH_NUM_SAMPLES_OFFSET		24

#define LRADC_CH_NUM_SAMPLES(x) \

				((x) << LRADC_CH_NUM_SAMPLES_OFFSET)

#define LRADC_CH_VALUE_MASK			0x3ffff

#define LRADC_CH_VALUE_OFFSET			0



#define LRADC_DELAY(n)				(0xd0 + (0x10 * (n)))

#define LRADC_DELAY_TRIGGER_LRADCS_MASK		(0xffUL << 24)

#define LRADC_DELAY_TRIGGER_LRADCS_OFFSET	24

#define LRADC_DELAY_TRIGGER(x) \

				(((x) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) & \

				LRADC_DELAY_TRIGGER_LRADCS_MASK)

#define LRADC_DELAY_KICK			BIT(20)

#define LRADC_DELAY_TRIGGER_DELAYS_MASK		(0xf << 16)

#define LRADC_DELAY_TRIGGER_DELAYS_OFFSET	16

#define LRADC_DELAY_TRIGGER_DELAYS(x) \

				(((x) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) & \

				LRADC_DELAY_TRIGGER_DELAYS_MASK)

#define LRADC_DELAY_LOOP_COUNT_MASK		(0x1f << 11)

#define LRADC_DELAY_LOOP_COUNT_OFFSET		11

#define LRADC_DELAY_LOOP(x) \

				(((x) << LRADC_DELAY_LOOP_COUNT_OFFSET) & \

				LRADC_DELAY_LOOP_COUNT_MASK)

#define LRADC_DELAY_DELAY_MASK			0x7ff

#define LRADC_DELAY_DELAY_OFFSET		0

#define LRADC_DELAY_DELAY(x) \

				(((x) << LRADC_DELAY_DELAY_OFFSET) & \

				LRADC_DELAY_DELAY_MASK)



#define LRADC_CTRL4				0x140

#define LRADC_CTRL4_LRADCSELECT_MASK(n)		(0xf << ((n) * 4))

#define LRADC_CTRL4_LRADCSELECT_OFFSET(n)	((n) * 4)

#define LRADC_CTRL4_LRADCSELECT(n, x) \

				(((x) << LRADC_CTRL4_LRADCSELECT_OFFSET(n)) & \

				LRADC_CTRL4_LRADCSELECT_MASK(n))



#define LRADC_RESOLUTION			12

#define LRADC_SINGLE_SAMPLE_MASK		((1 << LRADC_RESOLUTION) - 1)



#define BUFFER_VCHANS_LIMITED		0x3f

#define BUFFER_VCHANS_ALL		0xff



	/*

	 * Certain LRADC channels are shared between touchscreen

	 * and/or touch-buttons and generic LRADC block. Therefore when using

	 * either of these, these channels are not available for the regular

	 * sampling. The shared channels are as follows:

	 *

	 * CH0 -- Touch button #0

	 * CH1 -- Touch button #1

	 * CH2 -- Touch screen XPUL

	 * CH3 -- Touch screen YPLL

	 * CH4 -- Touch screen XNUL

	 * CH5 -- Touch screen YNLR

	 * CH6 -- Touch screen WIPER (5-wire only)

	 *

	 * The bit fields below represents which parts of the LRADC block are

	 * switched into special mode of operation. These channels can not

	 * be sampled as regular LRADC channels. The driver will refuse any

	 * attempt to sample these channels.

	 */

#define CHAN_MASK_TOUCHBUTTON		(BIT(1) | BIT(0))

#define CHAN_MASK_TOUCHSCREEN_4WIRE	(0xf << 2)

#define CHAN_MASK_TOUCHSCREEN_5WIRE	(0x1f << 2)



enum mxs_lradc_id {

	IMX23_LRADC,

	IMX28_LRADC,

};



enum mxs_lradc_ts_wires {

	MXS_LRADC_TOUCHSCREEN_NONE = 0,

	MXS_LRADC_TOUCHSCREEN_4WIRE,

	MXS_LRADC_TOUCHSCREEN_5WIRE,

};



/**

 * struct mxs_lradc

 * @soc: soc type (IMX23 or IMX28)

 * @clk: 2 kHz clock for delay units

 * @buffer_vchans: channels that can be used during buffered capture

 * @touchscreen_wire: touchscreen type (4-wire or 5-wire)

 * @use_touchbutton: button state (on or off)

 */

struct mxs_lradc {

	enum mxs_lradc_id	soc;

	struct clk		*clk;

	u8			buffer_vchans;



	enum mxs_lradc_ts_wires	touchscreen_wire;

	bool			use_touchbutton;

};



static inline u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)

{

	switch (lradc->soc) {

	case IMX23_LRADC:

		return LRADC_CTRL1_MX23_LRADC_IRQ_MASK;

	case IMX28_LRADC:

		return LRADC_CTRL1_MX28_LRADC_IRQ_MASK;

	default:

		return 0;

	}

}



#endif /* __MXS_LRADC_H */

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