Re: [PATCH v5 4/4] IIO : ADC: tiadc: Add support of TI's ADC driver

From: Jonathan Cameron
Date: Sat Oct 06 2012 - 05:40:44 EST

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In reply to: Patil, Rachna: "[PATCH v5 4/4] IIO : ADC: tiadc: Add support of TI's ADC driver"
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On 10/05/2012 08:34 AM, Patil, Rachna wrote:
> 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@xxxxxx>
> Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
I'll take this patch as soon as I know the mfd part
has been accepted (just in case any interfaces change!)
> ---
> Changes in v2:
> Addressed review comments from Matthias Kaehlcke
>
> Changes in v3:
> Addressed review comments from Jonathan Cameron.
> Added comments, new line appropriately.
>
> Changes in v4:
> Removed extra comments and variables.
> rename idev to indio_dev throughout the driver.
> Renamed structs for better readability.
>
> Changes in v5:
> No changes
>
> drivers/iio/adc/Kconfig | 7 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ti_am335x_adc.c | 260 +++++++++++++++++++++++++++
> drivers/mfd/ti_am335x_tscadc.c | 18 ++-
> include/linux/mfd/ti_am335x_tscadc.h | 9 +-
> include/linux/platform_data/ti_am335x_adc.h | 14 ++
> 6 files changed, 307 insertions(+), 2 deletions(-)
> create mode 100644 drivers/iio/adc/ti_am335x_adc.c
> create mode 100644 include/linux/platform_data/ti_am335x_adc.h
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 8a78b4f..1372f7e 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -22,4 +22,11 @@ config AT91_ADC
> help
> Say yes here to build support for Atmel AT91 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
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 52eec25..e716588 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -4,3 +4,4 @@
>
> obj-$(CONFIG_AD7266) += ad7266.o
> obj-$(CONFIG_AT91_ADC) += at91_adc.o
> +obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
> diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
> new file mode 100644
> index 0000000..02a43c8
> --- /dev/null
> +++ b/drivers/iio/adc/ti_am335x_adc.c
> @@ -0,0 +1,260 @@
> +/*
> + * 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@xxxxxx>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
> index d812be4..e947dd8 100644
> --- a/drivers/mfd/ti_am335x_tscadc.c
> +++ b/drivers/mfd/ti_am335x_tscadc.c
> @@ -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)
> diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
> index fc18b2e..c79ad5d 100644
> --- a/include/linux/mfd/ti_am335x_tscadc.h
> +++ b/include/linux/mfd/ti_am335x_tscadc.h
> @@ -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
> diff --git a/include/linux/platform_data/ti_am335x_adc.h b/include/linux/platform_data/ti_am335x_adc.h
> new file mode 100644
> index 0000000..e41d583
> --- /dev/null
> +++ b/include/linux/platform_data/ti_am335x_adc.h
> @@ -0,0 +1,14 @@
> +#ifndef __LINUX_TI_AM335X_ADC_H
> +#define __LINUX_TI_AM335X_ADC_H
> +
> +/**
> + * struct adc_data ADC Input information
> + * @adc_channels: Number of analog inputs
> + * available for ADC.
> + */
> +
> +struct adc_data {
> + unsigned int adc_channels;
> +};
> +
> +#endif
>
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Next message: Andrew Vagin: "[PATCH] pidns: remove recursion from free_pid_ns (v2)"
Previous message: Srikar Dronamraju: "Re: [PATCH 4/7] uprobes: Fix handle_swbp() vs unregister() +register() race"
In reply to: Patil, Rachna: "[PATCH v5 4/4] IIO : ADC: tiadc: Add support of TI's ADC driver"
Next in thread: Patil, Rachna: "[PATCH v5 1/4] input: TSC: ti_tscadc: Rename the existing touchscreen driver"
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