[PATCH 4/5] IIO : ADC: tiadc: Add support of TI's ADC driver

[PATCH 4/5] IIO : ADC: tiadc: Add support of TI's ADC driver

[Patil, Rachna]

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>
---
 drivers/iio/adc/Kconfig              |    7 +
 drivers/iio/adc/Makefile             |    1 +
 drivers/iio/adc/ti_adc.c             |  218 ++++++++++++++++++++++++++++++++++
 drivers/mfd/ti_tscadc.c              |    6 +
 include/linux/mfd/ti_tscadc.h        |    7 +-
 include/linux/platform_data/ti_adc.h |    9 ++
 6 files changed, 247 insertions(+), 1 deletions(-)
 create mode 100644 drivers/iio/adc/ti_adc.c
 create mode 100644 include/linux/platform_data/ti_adc.h

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 8a78b4f..ad32df8 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_ADC
+	tristate "TI's ADC driver"
+	depends on ARCH_OMAP2PLUS
+	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..a930cee 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_ADC) += ti_adc.o
diff --git a/drivers/iio/adc/ti_adc.c b/drivers/iio/adc/ti_adc.c
new file mode 100644
index 0000000..a476859
--- /dev/null
+++ b/drivers/iio/adc/ti_adc.c
@@ -0,0 +1,218 @@
+/*
+ * 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_tscadc.h>
+#include <linux/platform_data/ti_adc.h>
+
+struct adc_device {
+	struct ti_tscadc_dev *mfd_tscadc;
+	struct iio_dev *idev;
+	int adc_channels;
+};
+
+static unsigned int adc_readl(struct adc_device *adc, unsigned int reg)
+{
+	return readl(adc->mfd_tscadc->tscadc_base + reg);
+}
+
+static void adc_writel(struct adc_device *adc, unsigned int reg,
+					unsigned int val)
+{
+	writel(val, adc->mfd_tscadc->tscadc_base + reg);
+}
+
+static void adc_step_config(struct adc_device *adc_dev)
+{
+	unsigned int    stepconfig;
+	int i, channels = 0, steps;
+
+	steps = 16 - adc_dev->adc_channels;
+	channels = 8 - adc_dev->adc_channels;
+
+	/* Configure Step registers */
+	stepconfig = STEPCONFIG_AVG_16 | STEPCONFIG_FIFO1;
+
+	/*
+	 * There are 16 congiurable steps availabe 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
+	 */
+
+	for (i = (steps + 1); i < 17; i++) {
+		adc_writel(adc_dev, REG_STEPCONFIG(i),
+				stepconfig | (channels << 19));
+		adc_writel(adc_dev, REG_STEPDELAY(i),
+				STEPCONFIG_OPENDLY);
+		channels++;
+	}
+	adc_writel(adc_dev, REG_SE, STPENB_STEPENB);
+}
+
+static int tiadc_channel_init(struct iio_dev *idev, struct adc_device *adc_dev)
+{
+	struct iio_chan_spec *chan_array;
+	int i, idx = 0;
+
+	idev->num_channels = adc_dev->adc_channels;
+	chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
+					GFP_KERNEL);
+
+	if (chan_array == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < (idev->num_channels); i++) {
+		struct iio_chan_spec *chan = chan_array + idx;
+		chan->type = IIO_VOLTAGE;
+		chan->indexed = 1;
+		chan->channel = i;
+		chan->scan_type.sign = 'u';
+		chan->scan_type.realbits = 12;
+		chan->scan_type.storagebits = 32;
+		chan->scan_type.shift = 0;
+		idx++;
+	}
+
+	idev->channels = chan_array;
+	return idev->num_channels;
+}
+
+static void tiadc_channel_remove(struct iio_dev *idev)
+{
+	kfree(idev->channels);
+}
+
+static int tiadc_read_raw(struct iio_dev *idev,
+		struct iio_chan_spec const *chan,
+		int *val, int *val2, long mask)
+{
+	struct adc_device *adc_dev = iio_priv(idev);
+	int i;
+	unsigned int fifo1count, readx1;
+
+	fifo1count = adc_readl(adc_dev, REG_FIFO1CNT);
+	for (i = 0; i < fifo1count; i++) {
+		readx1 = adc_readl(adc_dev, REG_FIFO1);
+		if (i == chan->channel) {
+			readx1 = readx1 & 0xfff;
+			*val = readx1;
+		}
+	}
+	adc_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		*idev;
+	int			err;
+	struct adc_device	*adc_dev = NULL;
+	struct ti_tscadc_dev	*tscadc_dev = pdev->dev.platform_data;
+	struct mfd_tscadc_board	*board_data;
+
+	board_data = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;
+	if (!board_data) {
+		dev_err(tscadc_dev->dev, "Could not find platform data\n");
+		return -EINVAL;
+	}
+
+	idev = iio_device_alloc(sizeof(struct adc_device));
+	if (idev == NULL) {
+		dev_err(&pdev->dev, "failed to allocate iio device.\n");
+		err = -ENOMEM;
+		goto err_ret;
+	}
+	adc_dev = iio_priv(idev);
+
+	tscadc_dev->adc = adc_dev;
+	adc_dev->mfd_tscadc = tscadc_dev;
+	adc_dev->idev = idev;
+	adc_dev->adc_channels = board_data->adc_init->adc_channels;
+
+	idev->dev.parent = &pdev->dev;
+	idev->name = dev_name(&pdev->dev);
+	idev->modes = INDIO_DIRECT_MODE;
+	idev->info = &tiadc_info;
+
+	adc_step_config(adc_dev);
+
+	err = tiadc_channel_init(idev, adc_dev);
+	if (err < 0)
+		goto err_fail;
+
+	err = iio_device_register(idev);
+	if (err)
+		goto err_free_channels;
+
+	dev_info(&pdev->dev, "attached adc driver\n");
+	platform_set_drvdata(pdev, idev);
+
+	return 0;
+
+err_free_channels:
+	tiadc_channel_remove(idev);
+err_fail:
+	iio_device_unregister(idev);
+	iio_device_free(idev);
+err_ret:
+	platform_set_drvdata(pdev, NULL);
+	iio_device_free(idev);
+	return err;
+}
+
+static int __devexit tiadc_remove(struct platform_device *pdev)
+{
+	struct ti_tscadc_dev   *tscadc_dev = pdev->dev.platform_data;
+	struct adc_device	*adc_dev = tscadc_dev->adc;
+	struct iio_dev		*idev = adc_dev->idev;
+
+	iio_device_unregister(idev);
+	tiadc_channel_remove(idev);
+
+	tscadc_dev->adc = NULL;
+
+	iio_device_free(idev);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static struct platform_driver tiadc_driver = {
+	.driver = {
+		.name   = "tiadc",
+		.owner = THIS_MODULE,
+	},
+	.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");
diff --git a/drivers/mfd/ti_tscadc.c b/drivers/mfd/ti_tscadc.c
index 4fe8a9a..bf2d488 100644
--- a/drivers/mfd/ti_tscadc.c
+++ b/drivers/mfd/ti_tscadc.c
@@ -138,6 +138,12 @@ 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);
 	if (err < 0)
diff --git a/include/linux/mfd/ti_tscadc.h b/include/linux/mfd/ti_tscadc.h
index 74f07e7..ab51511 100644
--- a/include/linux/mfd/ti_tscadc.h
+++ b/include/linux/mfd/ti_tscadc.h
@@ -118,14 +118,16 @@
 #define ADC_CLK			3000000
 #define	MAX_CLK_DIV		7
 
-#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 {
@@ -136,6 +138,9 @@ struct ti_tscadc_dev {
 
 	/* tsc device */
 	struct tscadc *tsc;
+
+	/* adc device */
+	struct adc_device *adc;
 };
 
 #endif
diff --git a/include/linux/platform_data/ti_adc.h b/include/linux/platform_data/ti_adc.h
new file mode 100644
index 0000000..2fc9a6e
--- /dev/null
+++ b/include/linux/platform_data/ti_adc.h
@@ -0,0 +1,9 @@
+/**
+ * struct adc_data	ADC Input information
+ * @adc_channels:	Number of analog inputs
+ *			available for ADC.
+ */
+
+struct adc_data {
+	int adc_channels;
+};
-- 
1.7.1

Re: [PATCH 4/5] IIO : ADC: tiadc: Add support of TI's ADC driver

[Matthias Kaehlcke]

Hi,

El Thu, Aug 23, 2012 at 04:20:21PM +0530 Patil, Rachna ha dit:

> 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>
> ---
>
> diff --git a/drivers/iio/adc/ti_adc.c b/drivers/iio/adc/ti_adc.c
> ...
> +static int __devinit tiadc_probe(struct platform_device *pdev)
> +{
> +	struct iio_dev		*idev;
> +	int			err;
> +	struct adc_device	*adc_dev = NULL;
> +	struct ti_tscadc_dev	*tscadc_dev = pdev->dev.platform_data;
> +	struct mfd_tscadc_board	*board_data;
> +
> +	board_data = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;
> +	if (!board_data) {
> +		dev_err(tscadc_dev->dev, "Could not find platform data\n");
> +		return -EINVAL;
> +	}
> +
> +	idev = iio_device_alloc(sizeof(struct adc_device));
> +	if (idev == NULL) {
> +		dev_err(&pdev->dev, "failed to allocate iio device.\n");
> +		err = -ENOMEM;
> +		goto err_ret;
> +	}
> +	adc_dev = iio_priv(idev);
> +
> +	tscadc_dev->adc = adc_dev;
> +	adc_dev->mfd_tscadc = tscadc_dev;
> +	adc_dev->idev = idev;
> +	adc_dev->adc_channels = board_data->adc_init->adc_channels;
> +
> +	idev->dev.parent = &pdev->dev;
> +	idev->name = dev_name(&pdev->dev);
> +	idev->modes = INDIO_DIRECT_MODE;
> +	idev->info = &tiadc_info;
> +
> +	adc_step_config(adc_dev);
> +
> +	err = tiadc_channel_init(idev, adc_dev);
> +	if (err < 0)
> +		goto err_fail;
> +
> +	err = iio_device_register(idev);
> +	if (err)
> +		goto err_free_channels;
> +
> +	dev_info(&pdev->dev, "attached adc driver\n");
> +	platform_set_drvdata(pdev, idev);
> +
> +	return 0;
> +
> +err_free_channels:
> +	tiadc_channel_remove(idev);
> +err_fail:
> +	iio_device_unregister(idev);
> +	iio_device_free(idev);
> +err_ret:
> +	platform_set_drvdata(pdev, NULL);

not necessary, the platform device doesn't exist anymore

> +	iio_device_free(idev);

already done some lines above and could be executed without having
allocated the iio device (when iio_device_alloc() fails)

> +static int __devexit tiadc_remove(struct platform_device *pdev)
> +{
> +	struct ti_tscadc_dev   *tscadc_dev = pdev->dev.platform_data;
> +	struct adc_device	*adc_dev = tscadc_dev->adc;
> +	struct iio_dev		*idev = adc_dev->idev;
> +
> +	iio_device_unregister(idev);
> +	tiadc_channel_remove(idev);
> +
> +	tscadc_dev->adc = NULL;
> +
> +	iio_device_free(idev);
> +	platform_set_drvdata(pdev, NULL);

see above

best regards

-- 
Matthias Kaehlcke
Embedded Linux Developer
Amsterdam

               If sharing a thing in no way diminishes it,
               it is not rightly owned if it is not shared
                                                                 .''`.
    using free software / Debian GNU/Linux | http://debian.org  : :'  :
                                                                `. `'`
gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4                  `-

RE: [PATCH 4/5] IIO : ADC: tiadc: Add support of TI's ADC driver

[Patil, Rachna]

Hi,

On Fri, Aug 24, 2012 at 00:32:39, Matthias Kaehlcke wrote:
> Hi,
> 
> El Thu, Aug 23, 2012 at 04:20:21PM +0530 Patil, Rachna ha dit:
> 
> > 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>
> > ---
> >
> > diff --git a/drivers/iio/adc/ti_adc.c b/drivers/iio/adc/ti_adc.c ...
> > +static int __devinit tiadc_probe(struct platform_device *pdev) {
> > +	struct iio_dev		*idev;
> > +	int			err;
> > +	struct adc_device	*adc_dev = NULL;
> > +	struct ti_tscadc_dev	*tscadc_dev = pdev->dev.platform_data;
> > +	struct mfd_tscadc_board	*board_data;
> > +
> > +	board_data = (struct mfd_tscadc_board *)tscadc_dev->dev->platform_data;
> > +	if (!board_data) {
> > +		dev_err(tscadc_dev->dev, "Could not find platform data\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	idev = iio_device_alloc(sizeof(struct adc_device));
> > +	if (idev == NULL) {
> > +		dev_err(&pdev->dev, "failed to allocate iio device.\n");
> > +		err = -ENOMEM;
> > +		goto err_ret;
> > +	}
> > +	adc_dev = iio_priv(idev);
> > +
> > +	tscadc_dev->adc = adc_dev;
> > +	adc_dev->mfd_tscadc = tscadc_dev;
> > +	adc_dev->idev = idev;
> > +	adc_dev->adc_channels = board_data->adc_init->adc_channels;
> > +
> > +	idev->dev.parent = &pdev->dev;
> > +	idev->name = dev_name(&pdev->dev);
> > +	idev->modes = INDIO_DIRECT_MODE;
> > +	idev->info = &tiadc_info;
> > +
> > +	adc_step_config(adc_dev);
> > +
> > +	err = tiadc_channel_init(idev, adc_dev);
> > +	if (err < 0)
> > +		goto err_fail;
> > +
> > +	err = iio_device_register(idev);
> > +	if (err)
> > +		goto err_free_channels;
> > +
> > +	dev_info(&pdev->dev, "attached adc driver\n");
> > +	platform_set_drvdata(pdev, idev);
> > +
> > +	return 0;
> > +
> > +err_free_channels:
> > +	tiadc_channel_remove(idev);
> > +err_fail:
> > +	iio_device_unregister(idev);
> > +	iio_device_free(idev);
> > +err_ret:
> > +	platform_set_drvdata(pdev, NULL);
> 
> not necessary, the platform device doesn't exist anymore

Ok. I will correct this.

> 
> > +	iio_device_free(idev);
> 
> already done some lines above and could be executed without having allocated the iio device (when iio_device_alloc() fails)
> 
> > +static int __devexit tiadc_remove(struct platform_device *pdev) {
> > +	struct ti_tscadc_dev   *tscadc_dev = pdev->dev.platform_data;
> > +	struct adc_device	*adc_dev = tscadc_dev->adc;
> > +	struct iio_dev		*idev = adc_dev->idev;
> > +
> > +	iio_device_unregister(idev);
> > +	tiadc_channel_remove(idev);
> > +
> > +	tscadc_dev->adc = NULL;
> > +
> > +	iio_device_free(idev);
> > +	platform_set_drvdata(pdev, NULL);
> 
> see above

Yes, will correct this as well.

> 
> best regards
> 
> --
> Matthias Kaehlcke
> Embedded Linux Developer
> Amsterdam
> 
>                If sharing a thing in no way diminishes it,
>                it is not rightly owned if it is not shared
>                                                                  .''`.
>     using free software / Debian GNU/Linux | http://debian.org  : :'  :
>                                                                 `. `'`
> gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4                  `-
> 

Regards,
Rachna