IIO : ADC: tiadc: Add support of TI's ADC driver
This patch adds support for TI's ADC driver. This is a multifunctional device. Analog input lines are provided on which voltage measurements can be carried out. You can have upto 8 input lines. Signed-off-by: Patil, Rachna <rachna@ti.com> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Patil, Rachna
Samuel Ortiz
parent
2b99bafab1
commit
5e53a69b44
@ -60,4 +60,11 @@ config LP8788_ADC
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help
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Say yes here to build support for TI LP8788 ADC.
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config TI_AM335X_ADC
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tristate "TI's ADC driver"
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depends on MFD_TI_AM335X_TSCADC
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help
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Say yes here to build support for Texas Instruments ADC
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driver which is also a MFD client.
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endmenu
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@ -8,3 +8,4 @@ obj-$(CONFIG_AD7476) += ad7476.o
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obj-$(CONFIG_AD7791) += ad7791.o
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obj-$(CONFIG_AT91_ADC) += at91_adc.o
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obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
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obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
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260
drivers/iio/adc/ti_am335x_adc.c
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260
drivers/iio/adc/ti_am335x_adc.c
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@ -0,0 +1,260 @@
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/*
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* TI ADC MFD driver
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*
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* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of 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/init.h>
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/iio/iio.h>
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#include <linux/mfd/ti_am335x_tscadc.h>
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#include <linux/platform_data/ti_am335x_adc.h>
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struct tiadc_device {
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struct ti_tscadc_dev *mfd_tscadc;
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int channels;
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};
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static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
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{
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return readl(adc->mfd_tscadc->tscadc_base + reg);
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}
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static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
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unsigned int val)
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{
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writel(val, adc->mfd_tscadc->tscadc_base + reg);
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}
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static void tiadc_step_config(struct tiadc_device *adc_dev)
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{
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unsigned int stepconfig;
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int i, channels = 0, steps;
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/*
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* There are 16 configurable steps and 8 analog input
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* lines available which are shared between Touchscreen and ADC.
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*
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* Steps backwards i.e. from 16 towards 0 are used by ADC
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* depending on number of input lines needed.
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* Channel would represent which analog input
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* needs to be given to ADC to digitalize data.
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*/
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steps = TOTAL_STEPS - adc_dev->channels;
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channels = TOTAL_CHANNELS - adc_dev->channels;
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stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;
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for (i = (steps + 1); i <= TOTAL_STEPS; i++) {
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tiadc_writel(adc_dev, REG_STEPCONFIG(i),
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stepconfig | STEPCONFIG_INP(channels));
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tiadc_writel(adc_dev, REG_STEPDELAY(i),
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STEPCONFIG_OPENDLY);
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channels++;
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}
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tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
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}
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static int tiadc_channel_init(struct iio_dev *indio_dev, int channels)
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{
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struct iio_chan_spec *chan_array;
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int i;
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indio_dev->num_channels = channels;
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chan_array = kcalloc(indio_dev->num_channels,
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sizeof(struct iio_chan_spec), GFP_KERNEL);
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if (chan_array == NULL)
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return -ENOMEM;
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for (i = 0; i < (indio_dev->num_channels); i++) {
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struct iio_chan_spec *chan = chan_array + i;
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chan->type = IIO_VOLTAGE;
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chan->indexed = 1;
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chan->channel = i;
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chan->info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT;
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}
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indio_dev->channels = chan_array;
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return indio_dev->num_channels;
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}
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static void tiadc_channels_remove(struct iio_dev *indio_dev)
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{
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kfree(indio_dev->channels);
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}
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static int tiadc_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, long mask)
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{
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struct tiadc_device *adc_dev = iio_priv(indio_dev);
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int i;
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unsigned int fifo1count, readx1;
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/*
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* When the sub-system is first enabled,
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* the sequencer will always start with the
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* lowest step (1) and continue until step (16).
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* For ex: If we have enabled 4 ADC channels and
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* currently use only 1 out of them, the
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* sequencer still configures all the 4 steps,
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* leading to 3 unwanted data.
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* Hence we need to flush out this data.
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*/
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fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
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for (i = 0; i < fifo1count; i++) {
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readx1 = tiadc_readl(adc_dev, REG_FIFO1);
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if (i == chan->channel)
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*val = readx1 & 0xfff;
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}
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tiadc_writel(adc_dev, REG_SE, STPENB_STEPENB);
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return IIO_VAL_INT;
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}
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static const struct iio_info tiadc_info = {
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.read_raw = &tiadc_read_raw,
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};
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static int __devinit tiadc_probe(struct platform_device *pdev)
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{
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struct iio_dev *indio_dev;
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struct tiadc_device *adc_dev;
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struct ti_tscadc_dev *tscadc_dev = pdev->dev.platform_data;
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struct mfd_tscadc_board *pdata;
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int err;
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pdata = tscadc_dev->dev->platform_data;
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if (!pdata || !pdata->adc_init) {
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dev_err(&pdev->dev, "Could not find platform data\n");
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return -EINVAL;
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}
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indio_dev = iio_device_alloc(sizeof(struct tiadc_device));
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if (indio_dev == NULL) {
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dev_err(&pdev->dev, "failed to allocate iio device\n");
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err = -ENOMEM;
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goto err_ret;
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}
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adc_dev = iio_priv(indio_dev);
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adc_dev->mfd_tscadc = tscadc_dev;
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adc_dev->channels = pdata->adc_init->adc_channels;
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indio_dev->dev.parent = &pdev->dev;
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indio_dev->name = dev_name(&pdev->dev);
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->info = &tiadc_info;
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tiadc_step_config(adc_dev);
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err = tiadc_channel_init(indio_dev, adc_dev->channels);
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if (err < 0)
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goto err_free_device;
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err = iio_device_register(indio_dev);
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if (err)
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goto err_free_channels;
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platform_set_drvdata(pdev, indio_dev);
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return 0;
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err_free_channels:
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tiadc_channels_remove(indio_dev);
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err_free_device:
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iio_device_free(indio_dev);
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err_ret:
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return err;
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}
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static int __devexit tiadc_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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iio_device_unregister(indio_dev);
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tiadc_channels_remove(indio_dev);
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iio_device_free(indio_dev);
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return 0;
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}
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#ifdef CONFIG_PM
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static int tiadc_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 tiadc_device *adc_dev = iio_priv(indio_dev);
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struct ti_tscadc_dev *tscadc_dev = dev->platform_data;
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unsigned int idle;
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if (!device_may_wakeup(tscadc_dev->dev)) {
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idle = tiadc_readl(adc_dev, REG_CTRL);
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idle &= ~(CNTRLREG_TSCSSENB);
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tiadc_writel(adc_dev, REG_CTRL, (idle |
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CNTRLREG_POWERDOWN));
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}
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return 0;
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}
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static int tiadc_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 tiadc_device *adc_dev = iio_priv(indio_dev);
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unsigned int restore;
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/* Make sure ADC is powered up */
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restore = tiadc_readl(adc_dev, REG_CTRL);
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restore &= ~(CNTRLREG_POWERDOWN);
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tiadc_writel(adc_dev, REG_CTRL, restore);
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tiadc_step_config(adc_dev);
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return 0;
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}
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static const struct dev_pm_ops tiadc_pm_ops = {
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.suspend = tiadc_suspend,
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.resume = tiadc_resume,
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};
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#define TIADC_PM_OPS (&tiadc_pm_ops)
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#else
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#define TIADC_PM_OPS NULL
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#endif
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static struct platform_driver tiadc_driver = {
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.driver = {
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.name = "tiadc",
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.owner = THIS_MODULE,
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.pm = TIADC_PM_OPS,
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},
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.probe = tiadc_probe,
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.remove = __devexit_p(tiadc_remove),
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};
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module_platform_driver(tiadc_driver);
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MODULE_DESCRIPTION("TI ADC controller driver");
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MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
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MODULE_LICENSE("GPL");
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@ -25,6 +25,7 @@
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#include <linux/mfd/ti_am335x_tscadc.h>
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#include <linux/input/ti_am335x_tsc.h>
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#include <linux/platform_data/ti_am335x_adc.h>
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static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
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{
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@ -67,14 +68,23 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
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int irq;
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int err, ctrl;
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int clk_value, clock_rate;
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int tsc_wires;
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int tsc_wires, adc_channels = 0, total_channels;
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if (!pdata) {
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dev_err(&pdev->dev, "Could not find platform data\n");
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return -EINVAL;
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}
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if (pdata->adc_init)
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adc_channels = pdata->adc_init->adc_channels;
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tsc_wires = pdata->tsc_init->wires;
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total_channels = tsc_wires + adc_channels;
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if (total_channels > 8) {
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dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
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return -EINVAL;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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@ -172,6 +182,12 @@ static int __devinit ti_tscadc_probe(struct platform_device *pdev)
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cell->platform_data = tscadc;
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cell->pdata_size = sizeof(*tscadc);
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/* ADC Cell */
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cell = &tscadc->cells[ADC_CELL];
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cell->name = "tiadc";
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cell->platform_data = tscadc;
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cell->pdata_size = sizeof(*tscadc);
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err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
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TSCADC_CELLS, NULL, 0, NULL);
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if (err < 0)
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@ -120,15 +120,19 @@
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#define ADC_CLK 3000000
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#define MAX_CLK_DIV 7
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#define TOTAL_STEPS 16
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#define TOTAL_CHANNELS 8
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#define TSCADC_CELLS 1
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#define TSCADC_CELLS 2
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enum tscadc_cells {
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TSC_CELL,
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ADC_CELL,
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};
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struct mfd_tscadc_board {
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struct tsc_data *tsc_init;
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struct adc_data *adc_init;
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};
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struct ti_tscadc_dev {
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@ -140,6 +144,9 @@ struct ti_tscadc_dev {
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/* tsc device */
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struct titsc *tsc;
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/* adc device */
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struct adc_device *adc;
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};
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#endif
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14
include/linux/platform_data/ti_am335x_adc.h
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14
include/linux/platform_data/ti_am335x_adc.h
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@ -0,0 +1,14 @@
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#ifndef __LINUX_TI_AM335X_ADC_H
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#define __LINUX_TI_AM335X_ADC_H
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/**
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* struct adc_data ADC Input information
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* @adc_channels: Number of analog inputs
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* available for ADC.
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*/
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struct adc_data {
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unsigned int adc_channels;
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};
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#endif
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