IIO : ADC: tiadc: Add support of TI's ADC driver (5e53a69b) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/iio/adc/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -60,4 +60,11 @@ config LP8788_ADC
		help
		Say yes here to build support for TI LP8788 ADC.

		config TI_AM335X_ADC
		tristate "TI's ADC driver"
		depends on MFD_TI_AM335X_TSCADC
		help
		Say yes here to build support for Texas Instruments ADC
		driver which is also a MFD client.

		endmenu

drivers/iio/adc/Makefile

+1 −0

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		@@ -8,3 +8,4 @@ obj-$(CONFIG_AD7476) += ad7476.o
		obj-$(CONFIG_AD7791) += ad7791.o
		obj-$(CONFIG_AT91_ADC) += at91_adc.o
		obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
		obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o

drivers/iio/adc/ti_am335x_adc.c

0 → 100644

+260 −0

Original line number	Diff line number	Diff line
		/*
		* TI ADC MFD driver
		*
		* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.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 version 2.
		*
		* This program is distributed "as is" WITHOUT ANY WARRANTY of any
		* kind, whether express or implied; without even the implied warranty
		* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*/

		#include <linux/init.h>
		#include <linux/kernel.h>
		#include <linux/err.h>
		#include <linux/module.h>
		#include <linux/slab.h>
		#include <linux/interrupt.h>
		#include <linux/platform_device.h>
		#include <linux/io.h>
		#include <linux/iio/iio.h>

		#include <linux/mfd/ti_am335x_tscadc.h>
		#include <linux/platform_data/ti_am335x_adc.h>

		struct tiadc_device {
		struct ti_tscadc_dev *mfd_tscadc;
		int channels;
		};

		static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
		{
		return readl(adc->mfd_tscadc->tscadc_base + reg);
		}

		static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
		unsigned int val)
		{
		writel(val, adc->mfd_tscadc->tscadc_base + reg);
		}

		static void tiadc_step_config(struct tiadc_device *adc_dev)
		{
		unsigned int stepconfig;
		int i, channels = 0, steps;

		/*
		* There are 16 configurable steps and 8 analog input
		* lines available which are shared between Touchscreen and ADC.
		*
		* Steps backwards i.e. from 16 towards 0 are used by ADC
		* depending on number of input lines needed.
		* Channel would represent which analog input
		* needs to be given to ADC to digitalize data.
		*/

		steps = TOTAL_STEPS - adc_dev->channels;
		channels = TOTAL_CHANNELS - adc_dev->channels;

		stepconfig = STEPCONFIG_AVG_16 \| STEPCONFIG_FIFO1;

		for (i = (steps + 1); i <= TOTAL_STEPS; i++) {
		tiadc_writel(adc_dev, REG_STEPCONFIG(i),
		stepconfig \| STEPCONFIG_INP(channels));
		tiadc_writel(adc_dev, REG_STEPDELAY(i),
		STEPCONFIG_OPENDLY);
		channels++;
		}
		tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
		}

		static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
		{
		struct iio_chan_spec *chan_array;
		int i;

		indio_dev->num_channels = channels;
		chan_array = kcalloc(indio_dev->num_channels,
		sizeof(struct iio_chan_spec), GFP_KERNEL);

		if (chan_array == NULL)
		return -ENOMEM;

		for (i = 0; i < (indio_dev->num_channels); i++) {
		struct iio_chan_spec *chan = chan_array + i;
		chan->type = IIO_VOLTAGE;
		chan->indexed = 1;
		chan->channel = i;
		chan->info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT;
		}

		indio_dev->channels = chan_array;

		return indio_dev->num_channels;
		}

		static void tiadc_channels_remove(struct iio_dev *indio_dev)
		{
		kfree(indio_dev->channels);
		}

		static int tiadc_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int val, int val2, long mask)
		{
		struct tiadc_device *adc_dev = iio_priv(indio_dev);
		int i;
		unsigned int fifo1count, readx1;

		/*
		* When the sub-system is first enabled,
		* the sequencer will always start with the
		* lowest step (1) and continue until step (16).
		* For ex: If we have enabled 4 ADC channels and
		* currently use only 1 out of them, the
		* sequencer still configures all the 4 steps,
		* leading to 3 unwanted data.
		* Hence we need to flush out this data.
		*/

		fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
		for (i = 0; i < fifo1count; i++) {
		readx1 = tiadc_readl(adc_dev, REG_FIFO1);
		if (i == chan->channel)
		*val = readx1 & 0xfff;
		}
		tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);

		return IIO_VAL_INT;
		}

		static const struct iio_info tiadc_info = {
		.read_raw = &tiadc_read_raw,
		};

		static int __devinit tiadc_probe(struct platform_device *pdev)
		{
		struct iio_dev *indio_dev;
		struct tiadc_device *adc_dev;
		struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
		struct mfd_tscadc_board *pdata;
		int err;

		pdata = tscadc_dev->dev->platform_data;
		if (!pdata \|\| !pdata->adc_init) {
		dev_err(&pdev->dev, "Could not find platform data\n");
		return -EINVAL;
		}

		indio_dev = iio_device_alloc(sizeof(struct tiadc_device));
		if (indio_dev == NULL) {
		dev_err(&pdev->dev, "failed to allocate iio device\n");
		err = -ENOMEM;
		goto err_ret;
		}
		adc_dev = iio_priv(indio_dev);

		adc_dev->mfd_tscadc = tscadc_dev;
		adc_dev->channels = pdata->adc_init->adc_channels;

		indio_dev->dev.parent = &pdev->dev;
		indio_dev->name = dev_name(&pdev->dev);
		indio_dev->modes = INDIO_DIRECT_MODE;
		indio_dev->info = &tiadc_info;

		tiadc_step_config(adc_dev);

		err = tiadc_channel_init(indio_dev, adc_dev->channels);
		if (err < 0)
		goto err_free_device;

		err = iio_device_register(indio_dev);
		if (err)
		goto err_free_channels;

		platform_set_drvdata(pdev, indio_dev);

		return 0;

		err_free_channels:
		tiadc_channels_remove(indio_dev);
		err_free_device:
		iio_device_free(indio_dev);
		err_ret:
		return err;
		}

		static int __devexit tiadc_remove(struct platform_device *pdev)
		{
		struct iio_dev *indio_dev = platform_get_drvdata(pdev);

		iio_device_unregister(indio_dev);
		tiadc_channels_remove(indio_dev);

		iio_device_free(indio_dev);

		return 0;
		}

		#ifdef CONFIG_PM
		static int tiadc_suspend(struct device *dev)
		{
		struct iio_dev *indio_dev = dev_get_drvdata(dev);
		struct tiadc_device *adc_dev = iio_priv(indio_dev);
		struct ti_tscadc_dev *tscadc_dev = dev->platform_data;
		unsigned int idle;

		if (!device_may_wakeup(tscadc_dev->dev)) {
		idle = tiadc_readl(adc_dev, REG_CTRL);
		idle &= ~(CNTRLREG_TSCSSENB);
		tiadc_writel(adc_dev, REG_CTRL, (idle \|
		CNTRLREG_POWERDOWN));
		}

		return 0;
		}

		static int tiadc_resume(struct device *dev)
		{
		struct iio_dev *indio_dev = dev_get_drvdata(dev);
		struct tiadc_device *adc_dev = iio_priv(indio_dev);
		unsigned int restore;

		/* Make sure ADC is powered up */
		restore = tiadc_readl(adc_dev, REG_CTRL);
		restore &= ~(CNTRLREG_POWERDOWN);
		tiadc_writel(adc_dev, REG_CTRL, restore);

		tiadc_step_config(adc_dev);

		return 0;
		}

		static const struct dev_pm_ops tiadc_pm_ops = {
		.suspend = tiadc_suspend,
		.resume = tiadc_resume,
		};
		#define TIADC_PM_OPS (&tiadc_pm_ops)
		#else
		#define TIADC_PM_OPS NULL
		#endif

		static struct platform_driver tiadc_driver = {
		.driver = {
		.name = "tiadc",
		.owner = THIS_MODULE,
		.pm = TIADC_PM_OPS,
		},
		.probe = tiadc_probe,
		.remove = __devexit_p(tiadc_remove),
		};

		module_platform_driver(tiadc_driver);

		MODULE_DESCRIPTION("TI ADC controller driver");
		MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
		MODULE_LICENSE("GPL");

drivers/mfd/ti_am335x_tscadc.c

+17 −1

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@

		#include <linux/mfd/ti_am335x_tscadc.h>
		#include <linux/input/ti_am335x_tsc.h>
		#include <linux/platform_data/ti_am335x_adc.h>

		static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
		{
		@@ -67,14 +68,23 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
		int irq;
		int err, ctrl;
		int clk_value, clock_rate;
		int tsc_wires;
		int tsc_wires, adc_channels = 0, total_channels;

		if (!pdata) {
		dev_err(&pdev->dev, "Could not find platform data\n");
		return -EINVAL;
		}

		if (pdata->adc_init)
		adc_channels = pdata->adc_init->adc_channels;

		tsc_wires = pdata->tsc_init->wires;
		total_channels = tsc_wires + adc_channels;

		if (total_channels > 8) {
		dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
		return -EINVAL;
		}

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		if (!res) {
		@@ -172,6 +182,12 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
		cell->platform_data = tscadc;
		cell->pdata_size = sizeof(*tscadc);

		/* ADC Cell */
		cell = &tscadc->cells[ADC_CELL];
		cell->name = "tiadc";
		cell->platform_data = tscadc;
		cell->pdata_size = sizeof(*tscadc);

		err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
		TSCADC_CELLS, NULL, 0, NULL);
		if (err < 0)

include/linux/mfd/ti_am335x_tscadc.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -120,15 +120,19 @@

		#define ADC_CLK 3000000
		#define MAX_CLK_DIV 7
		#define TOTAL_STEPS 16
		#define TOTAL_CHANNELS 8

		#define TSCADC_CELLS 1
		#define TSCADC_CELLS 2

		enum tscadc_cells {
		TSC_CELL,
		ADC_CELL,
		};

		struct mfd_tscadc_board {
		struct tsc_data *tsc_init;
		struct adc_data *adc_init;
		};

		struct ti_tscadc_dev {
		@@ -140,6 +144,9 @@ struct ti_tscadc_dev {

		/* tsc device */
		struct titsc *tsc;

		/* adc device */
		struct adc_device *adc;
		};

		#endif