[PATCH] Add ADC driver for G20 and G45 evaluation boards

[PATCH] Add ADC driver for G20 and G45 evaluation boards

[Maxime Ripard]

Hi all,

Here is the improved version of what I've been posting some time ago.
Some things changed since last version:
  - Support for Hardware triggers for the G20 has been added
  - Support for the AT91SAM9M10G45 board has been added too, both for
    software and hardware triggers
  - The driver is now in drivers/staging/iio to include all these features.

The first three patches should not have changed much since last post, so it
should be pretty ok.

Thanks,
Maxime

[PATCH] Add ADC driver for G20 and G45 evaluation boards

[Maxime Ripard]

Hi all,

Here is the improved version of what I've been posting some time ago.
Some things changed since last version:
  - Support for Hardware triggers for the G20 has been added
  - Support for the AT91SAM9M10G45 board has been added too, both for
    software and hardware triggers
  - The driver is now in drivers/staging/iio to include all these features.

The first three patches should not have changed much since last post, so it
should be pretty ok.

Thanks,
Maxime

[PATCH 1/5] ARM: AT91: Add platform data for the AT91 ADCs

[Maxime Ripard]

The AT91 SoCs often embeds an ADC. This patch adds the needed
platform data to specify the informations required by the driver
to work properly.

For now, we only need the reference voltage and which channels
are available on the board.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
---
 include/linux/platform_data/at91_adc.h |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)
 create mode 100644 include/linux/platform_data/at91_adc.h

diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
new file mode 100644
index 0000000..1f71510
--- /dev/null
+++ b/include/linux/platform_data/at91_adc.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2011 Free Electrons
+ *
+ * Licensed under the GPLv2 or later.
+ *
+ */
+
+#ifndef _AT91_ADC_H_
+#define _AT91_ADC_H_
+
+/**
+ * struct at91_adc_data - platform data for ADC driver
+ * @channels_used:	channels in use on the board as a bitmask
+ * @vref:		Reference voltage for the ADC in millivolts
+ */
+struct at91_adc_data {
+	unsigned long	channels_used;
+	u16		vref;
+};
+
+extern void __init at91_add_device_adc(struct at91_adc_data *data);
+
+#endif
-- 
1.7.5.4

[PATCH 1/5] ARM: AT91: Add platform data for the AT91 ADCs

[Maxime Ripard]

The AT91 SoCs often embeds an ADC. This patch adds the needed
platform data to specify the informations required by the driver
to work properly.

For now, we only need the reference voltage and which channels
are available on the board.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
---
 include/linux/platform_data/at91_adc.h |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)
 create mode 100644 include/linux/platform_data/at91_adc.h

diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
new file mode 100644
index 0000000..1f71510
--- /dev/null
+++ b/include/linux/platform_data/at91_adc.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2011 Free Electrons
+ *
+ * Licensed under the GPLv2 or later.
+ *
+ */
+
+#ifndef _AT91_ADC_H_
+#define _AT91_ADC_H_
+
+/**
+ * struct at91_adc_data - platform data for ADC driver
+ * @channels_used:	channels in use on the board as a bitmask
+ * @vref:		Reference voltage for the ADC in millivolts
+ */
+struct at91_adc_data {
+	unsigned long	channels_used;
+	u16		vref;
+};
+
+extern void __init at91_add_device_adc(struct at91_adc_data *data);
+
+#endif
-- 
1.7.5.4

Re: [PATCH 1/5] ARM: AT91: Add platform data for the AT91 ADCs

[Jonathan Cameron]

On 4/5/2012 5:01 PM, Maxime Ripard wrote:
> The AT91 SoCs often embeds an ADC. This patch adds the needed
> platform data to specify the informations required by the driver
> to work properly.
>
> For now, we only need the reference voltage and which channels
> are available on the board.
Trivial, though I'm in a fussy mood so see below.
>
> Signed-off-by: Maxime Ripard<maxime.ripard@free-electrons.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
>
> Cc: Nicolas Ferre<nicolas.ferre@atmel.com>
> Cc: Patrice Vilchez<patrice.vilchez@atmel.com>
> Cc: Thomas Petazzoni<thomas.petazzoni@free-electrons.com>
> Cc: Jean-Christophe PLAGNIOL-VILLARD<plagnioj@jcrosoft.com>
> ---
>   include/linux/platform_data/at91_adc.h |   23 +++++++++++++++++++++++
>   1 files changed, 23 insertions(+), 0 deletions(-)
>   create mode 100644 include/linux/platform_data/at91_adc.h
>
> diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
> new file mode 100644
> index 0000000..1f71510
> --- /dev/null
> +++ b/include/linux/platform_data/at91_adc.h
> @@ -0,0 +1,23 @@
> +/*
> + * Copyright (C) 2011 Free Electrons
> + *
> + * Licensed under the GPLv2 or later.
If we are really being nitpicky, no point in the next blank line!
> + *
> + */
> +
> +#ifndef _AT91_ADC_H_
> +#define _AT91_ADC_H_
> +
> +/**
> + * struct at91_adc_data - platform data for ADC driver
> + * @channels_used:	channels in use on the board as a bitmask
> + * @vref:		Reference voltage for the ADC in millivolts
> + */
> +struct at91_adc_data {
> +	unsigned long	channels_used;
> +	u16		vref;
> +};
> +
> +extern void __init at91_add_device_adc(struct at91_adc_data *data);
> +
> +#endif

[PATCH 1/5] ARM: AT91: Add platform data for the AT91 ADCs

[Jonathan Cameron]

On 4/5/2012 5:01 PM, Maxime Ripard wrote:
> The AT91 SoCs often embeds an ADC. This patch adds the needed
> platform data to specify the informations required by the driver
> to work properly.
>
> For now, we only need the reference voltage and which channels
> are available on the board.
Trivial, though I'm in a fussy mood so see below.
>
> Signed-off-by: Maxime Ripard<maxime.ripard@free-electrons.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
>
> Cc: Nicolas Ferre<nicolas.ferre@atmel.com>
> Cc: Patrice Vilchez<patrice.vilchez@atmel.com>
> Cc: Thomas Petazzoni<thomas.petazzoni@free-electrons.com>
> Cc: Jean-Christophe PLAGNIOL-VILLARD<plagnioj@jcrosoft.com>
> ---
>   include/linux/platform_data/at91_adc.h |   23 +++++++++++++++++++++++
>   1 files changed, 23 insertions(+), 0 deletions(-)
>   create mode 100644 include/linux/platform_data/at91_adc.h
>
> diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
> new file mode 100644
> index 0000000..1f71510
> --- /dev/null
> +++ b/include/linux/platform_data/at91_adc.h
> @@ -0,0 +1,23 @@
> +/*
> + * Copyright (C) 2011 Free Electrons
> + *
> + * Licensed under the GPLv2 or later.
If we are really being nitpicky, no point in the next blank line!
> + *
> + */
> +
> +#ifndef _AT91_ADC_H_
> +#define _AT91_ADC_H_
> +
> +/**
> + * struct at91_adc_data - platform data for ADC driver
> + * @channels_used:	channels in use on the board as a bitmask
> + * @vref:		Reference voltage for the ADC in millivolts
> + */
> +struct at91_adc_data {
> +	unsigned long	channels_used;
> +	u16		vref;
> +};
> +
> +extern void __init at91_add_device_adc(struct at91_adc_data *data);
> +
> +#endif

[PATCH 2/5] ARM: AT91: IIO: Add AT91 ADC driver.

[Maxime Ripard]

Add the IIO driver for the AT91 ADCs. It only supports and has
been tested on the SAM9G20 evaluation boards, but support for
other boards will come eventually.

This ADC is a multi-channel ADC with support for both hardware
and software triggers.

This first version only supports software triggers.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
---
 drivers/staging/iio/adc/Kconfig    |    6 +
 drivers/staging/iio/adc/Makefile   |    1 +
 drivers/staging/iio/adc/at91_adc.c |  382 ++++++++++++++++++++++++++++++++++++
 3 files changed, 389 insertions(+), 0 deletions(-)
 create mode 100644 drivers/staging/iio/adc/at91_adc.c

diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index 592eabd..1494838 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -169,6 +169,12 @@ config AD7280
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7280a
 
+config AT91_ADC
+	tristate "Atmel AT91 ADC"
+	depends on SYSFS && ARCH_AT91
+	help
+	  Say yes here to build support for Atmel AT91 ADC.
+
 config MAX1363
 	tristate "Maxim max1363 ADC driver"
 	depends on I2C
diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
index f83ab95..8cb6d1c 100644
--- a/drivers/staging/iio/adc/Makefile
+++ b/drivers/staging/iio/adc/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_ADT7310) += adt7310.o
 obj-$(CONFIG_ADT7410) += adt7410.o
 obj-$(CONFIG_AD7280) += ad7280a.o
 obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
+obj-$(CONFIG_AT91_ADC) += at91_adc.o
diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
new file mode 100644
index 0000000..c76516a
--- /dev/null
+++ b/drivers/staging/iio/adc/at91_adc.c
@@ -0,0 +1,382 @@
+/*
+ * Driver for the ADC present in the Atmel AT91 evaluation boards.
+ *
+ * Copyright 2011 Free Electrons
+ *
+ * Licensed under the GPLv2 or later.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include "../iio.h"
+#include <linux/platform_data/at91_adc.h>
+
+#include <mach/at91_adc.h>
+#include <mach/cpu.h>
+
+/**
+ * struct at91_adc_desc - description of the ADC on the board
+ * @clock:		ADC clock as specified by the datasheet, in Hz.
+ * @clock_name		Name of the ADC clock as defined in the clock tree
+ * @num_channels:	global number of channels available on the board (to
+			specify which channels are indeed in use on the
+			board, see the channels_used bitmask in the platform
+			data)
+ * @startup_time:	startup time of the ADC in microseconds
+ */
+struct at91_adc_desc {
+	u32			clock;
+	char			*clock_name;
+	u8			num_channels;
+	u8			startup_time;
+};
+
+struct at91_adc_state {
+	unsigned long		channels_mask;
+	struct clk		*clk;
+	bool			done;
+	struct at91_adc_desc	*desc;
+	int			irq;
+	u16			last_value;
+	struct mutex		lock;
+	void __iomem		*reg_base;
+	u32			vref_mv;
+	wait_queue_head_t	wq_data_avail;
+};
+
+static struct at91_adc_desc at91_adc_desc_sam9g20 = {
+	.clock = 5000000,
+	.clock_name = "adc_clk",
+	.num_channels = 4,
+	.startup_time = 10,
+};
+
+static int at91_adc_select_soc(struct at91_adc_state *st)
+{
+	if (cpu_is_at91sam9g20()) {
+		st->desc = &at91_adc_desc_sam9g20;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static inline u32 at91_adc_reg_read(struct at91_adc_state *st,
+				    u8 reg)
+{
+	return readl_relaxed(st->reg_base + reg);
+}
+
+static inline void at91_adc_reg_write(struct at91_adc_state *st,
+				      u8 reg,
+				      u32 val)
+{
+	writel_relaxed(val, st->reg_base + reg);
+}
+
+static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
+{
+	struct iio_dev *idev = private;
+	struct at91_adc_state *st = iio_priv(idev);
+	unsigned int status = at91_adc_reg_read(st, AT91_ADC_SR);
+
+	if (!(status & AT91_ADC_DRDY))
+		return IRQ_HANDLED;
+
+	if (status & st->channels_mask) {
+		st->done = true;
+		st->last_value = at91_adc_reg_read(st, AT91_ADC_LCDR);
+	}
+
+	wake_up_interruptible(&st->wq_data_avail);
+
+	return IRQ_HANDLED;
+}
+
+static int at91_adc_channel_init(struct iio_dev *idev,
+				 struct at91_adc_data *pdata)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	struct iio_chan_spec *chan_array;
+	int bit, idx = 0;
+
+	idev->num_channels = bitmap_weight(&pdata->channels_used,
+					   st->desc->num_channels);
+	chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
+			     GFP_KERNEL);
+
+	if (chan_array == NULL)
+		return -ENOMEM;
+
+	for_each_set_bit(bit, &pdata->channels_used, st->desc->num_channels) {
+		struct iio_chan_spec *chan = chan_array + idx;
+		chan->type = IIO_VOLTAGE;
+		chan->indexed = 1;
+		chan->channel = bit;
+		chan->scan_type.sign = 'u';
+		chan->scan_type.realbits = 10;
+		chan->scan_type.storagebits = 16;
+		chan->info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT;
+		idx++;
+	}
+
+	idev->channels = chan_array;
+	return idev->num_channels;
+}
+
+static void at91_adc_channel_remove(struct iio_dev *idev)
+{
+	kfree(idev->channels);
+}
+
+static int at91_adc_read_raw(struct iio_dev *idev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	int ret;
+
+	switch (mask) {
+	case 0:
+		mutex_lock(&st->lock);
+
+		at91_adc_reg_write(st, AT91_ADC_CHER,
+				  AT91_ADC_CH(chan->channel));
+		at91_adc_reg_write(st, AT91_ADC_IER,
+				  AT91_ADC_EOC(chan->channel));
+		at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_START);
+
+		ret = wait_event_interruptible_timeout(st->wq_data_avail,
+						       st->done,
+						       msecs_to_jiffies(1000));
+		if (ret == 0)
+			return -ETIMEDOUT;
+		else if (ret < 0)
+			return ret;
+
+		*val = st->last_value;
+
+		at91_adc_reg_write(st, AT91_ADC_CHDR,
+				  AT91_ADC_CH(chan->channel));
+		at91_adc_reg_write(st, AT91_ADC_IDR,
+				  AT91_ADC_EOC(chan->channel));
+
+		st->last_value = 0;
+		st->done = false;
+		mutex_unlock(&st->lock);
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = (st->vref_mv * 1000) >> chan->scan_type.realbits;
+		*val2 = 0;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_info at91_adc_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &at91_adc_read_raw,
+};
+
+static int __devinit at91_adc_probe(struct platform_device *pdev)
+{
+	unsigned int prsc, mstrclk, ticks;
+	int ret;
+	struct iio_dev *idev;
+	struct at91_adc_state *st;
+	struct resource *res;
+	struct at91_adc_data *pdata = pdev->dev.platform_data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "No resource defined\n");
+		ret = -ENXIO;
+		goto error_ret;
+	}
+
+	idev = iio_allocate_device(sizeof(struct at91_adc_state));
+	if (idev == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	platform_set_drvdata(pdev, idev);
+
+	idev->dev.parent = &pdev->dev;
+	idev->name = dev_name(&pdev->dev);
+	idev->modes = INDIO_DIRECT_MODE;
+	idev->info = &at91_adc_info;
+
+	st = iio_priv(idev);
+	ret = at91_adc_select_soc(st);
+	if (ret) {
+		dev_err(&pdev->dev, "SoC unknown\n");
+		goto error_free_device;
+	}
+
+	st->irq = platform_get_irq(pdev, 0);
+	if (st->irq < 0) {
+		dev_err(&pdev->dev, "No IRQ ID is designated\n");
+		ret = -ENODEV;
+		goto error_free_device;
+	}
+
+	if (!request_mem_region(res->start, resource_size(res),
+				"AT91 adc registers")) {
+		dev_err(&pdev->dev, "Resources are unavailable.\n");
+		ret = -EBUSY;
+		goto error_free_device;
+	}
+
+	st->reg_base = ioremap(res->start, resource_size(res));
+	if (!st->reg_base) {
+		dev_err(&pdev->dev, "Failed to map registers.\n");
+		ret = -ENOMEM;
+		goto error_release_mem;
+	}
+
+	/*
+	 * Disable all IRQs before setting up the handler
+	 */
+	at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_SWRST);
+	at91_adc_reg_write(st, AT91_ADC_IDR, 0xFFFFFFFF);
+	ret = request_irq(st->irq,
+			  at91_adc_eoc_trigger,
+			  0,
+			  pdev->dev.driver->name,
+			  idev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
+		goto error_unmap_reg;
+	}
+
+	st->clk = clk_get(&pdev->dev, st->desc->clock_name);
+	if (IS_ERR(st->clk)) {
+		dev_err(&pdev->dev, "Failed to get the clock.\n");
+		ret = PTR_ERR(st->clk);
+		goto error_free_irq;
+	}
+
+	clk_enable(st->clk);
+	mstrclk = clk_get_rate(st->clk);
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform data available.\n");
+		ret = -EINVAL;
+		goto error_free_clk;
+	}
+
+	if (!st->desc->clock) {
+		dev_err(&pdev->dev, "No ADCClock available.\n");
+		ret = -EINVAL;
+		goto error_free_clk;
+	}
+
+	/*
+	 * Prescaler rate computation using the formula from the Atmel's
+	 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
+	 * specified by the electrical characteristics of the board.
+	 */
+	prsc = (mstrclk / (2 * st->desc->clock)) - 1;
+
+	if (!st->desc->startup_time) {
+		dev_err(&pdev->dev, "No startup time available.\n");
+		ret = -EINVAL;
+		goto error_free_clk;
+	}
+
+	/*
+	 * Number of ticks needed to cover the startup time of the ADC as
+	 * defined in the electrical characteristics of the board, divided by 8.
+	 * The formula thus is : Startup Time = (ticks + 1) * 8 / ADC Clock
+	 */
+	ticks = round_up((st->desc->startup_time * st->desc->clock /
+			  1000000) - 1, 8) / 8;
+	at91_adc_reg_write(st, AT91_ADC_MR,
+			  (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
+			  (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
+
+	/* Setup the ADC channels available on the board */
+	ret = at91_adc_channel_init(idev, pdata);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
+		goto error_free_clk;
+	}
+
+	init_waitqueue_head(&st->wq_data_avail);
+	mutex_init(&st->lock);
+
+	st->vref_mv = pdata->vref;
+	st->channels_mask = pdata->channels_used;
+
+	ret = iio_device_register(idev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't register the device.\n");
+		goto error_free_channels;
+	}
+
+	return 0;
+
+error_free_channels:
+	at91_adc_channel_remove(idev);
+error_free_clk:
+	clk_disable(st->clk);
+	clk_put(st->clk);
+error_free_irq:
+	free_irq(st->irq, idev);
+error_unmap_reg:
+	iounmap(st->reg_base);
+error_release_mem:
+	release_mem_region(res->start, resource_size(res));
+error_free_device:
+	iio_free_device(idev);
+error_ret:
+	return ret;
+}
+
+static int __devexit at91_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *idev = platform_get_drvdata(pdev);
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	struct at91_adc_state *st = iio_priv(idev);
+
+	iio_device_unregister(idev);
+	at91_adc_channel_remove(idev);
+	clk_disable(st->clk);
+	clk_put(st->clk);
+	free_irq(st->irq, idev);
+	iounmap(st->reg_base);
+	release_mem_region(res->start, resource_size(res));
+	iio_free_device(idev);
+
+	return 0;
+}
+
+static struct platform_driver at91_adc_driver = {
+	.probe = at91_adc_probe,
+	.remove = __devexit_p(at91_adc_remove),
+	.driver = {
+		   .name = "at91_adc",
+	},
+};
+
+module_platform_driver(at91_adc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
-- 
1.7.5.4

[PATCH 2/5] ARM: AT91: IIO: Add AT91 ADC driver.

[Maxime Ripard]

Add the IIO driver for the AT91 ADCs. It only supports and has
been tested on the SAM9G20 evaluation boards, but support for
other boards will come eventually.

This ADC is a multi-channel ADC with support for both hardware
and software triggers.

This first version only supports software triggers.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
---
 drivers/staging/iio/adc/Kconfig    |    6 +
 drivers/staging/iio/adc/Makefile   |    1 +
 drivers/staging/iio/adc/at91_adc.c |  382 ++++++++++++++++++++++++++++++++++++
 3 files changed, 389 insertions(+), 0 deletions(-)
 create mode 100644 drivers/staging/iio/adc/at91_adc.c

diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index 592eabd..1494838 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -169,6 +169,12 @@ config AD7280
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7280a
 
+config AT91_ADC
+	tristate "Atmel AT91 ADC"
+	depends on SYSFS && ARCH_AT91
+	help
+	  Say yes here to build support for Atmel AT91 ADC.
+
 config MAX1363
 	tristate "Maxim max1363 ADC driver"
 	depends on I2C
diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
index f83ab95..8cb6d1c 100644
--- a/drivers/staging/iio/adc/Makefile
+++ b/drivers/staging/iio/adc/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_ADT7310) += adt7310.o
 obj-$(CONFIG_ADT7410) += adt7410.o
 obj-$(CONFIG_AD7280) += ad7280a.o
 obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
+obj-$(CONFIG_AT91_ADC) += at91_adc.o
diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
new file mode 100644
index 0000000..c76516a
--- /dev/null
+++ b/drivers/staging/iio/adc/at91_adc.c
@@ -0,0 +1,382 @@
+/*
+ * Driver for the ADC present in the Atmel AT91 evaluation boards.
+ *
+ * Copyright 2011 Free Electrons
+ *
+ * Licensed under the GPLv2 or later.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include "../iio.h"
+#include <linux/platform_data/at91_adc.h>
+
+#include <mach/at91_adc.h>
+#include <mach/cpu.h>
+
+/**
+ * struct at91_adc_desc - description of the ADC on the board
+ * @clock:		ADC clock as specified by the datasheet, in Hz.
+ * @clock_name		Name of the ADC clock as defined in the clock tree
+ * @num_channels:	global number of channels available on the board (to
+			specify which channels are indeed in use on the
+			board, see the channels_used bitmask in the platform
+			data)
+ * @startup_time:	startup time of the ADC in microseconds
+ */
+struct at91_adc_desc {
+	u32			clock;
+	char			*clock_name;
+	u8			num_channels;
+	u8			startup_time;
+};
+
+struct at91_adc_state {
+	unsigned long		channels_mask;
+	struct clk		*clk;
+	bool			done;
+	struct at91_adc_desc	*desc;
+	int			irq;
+	u16			last_value;
+	struct mutex		lock;
+	void __iomem		*reg_base;
+	u32			vref_mv;
+	wait_queue_head_t	wq_data_avail;
+};
+
+static struct at91_adc_desc at91_adc_desc_sam9g20 = {
+	.clock = 5000000,
+	.clock_name = "adc_clk",
+	.num_channels = 4,
+	.startup_time = 10,
+};
+
+static int at91_adc_select_soc(struct at91_adc_state *st)
+{
+	if (cpu_is_at91sam9g20()) {
+		st->desc = &at91_adc_desc_sam9g20;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static inline u32 at91_adc_reg_read(struct at91_adc_state *st,
+				    u8 reg)
+{
+	return readl_relaxed(st->reg_base + reg);
+}
+
+static inline void at91_adc_reg_write(struct at91_adc_state *st,
+				      u8 reg,
+				      u32 val)
+{
+	writel_relaxed(val, st->reg_base + reg);
+}
+
+static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
+{
+	struct iio_dev *idev = private;
+	struct at91_adc_state *st = iio_priv(idev);
+	unsigned int status = at91_adc_reg_read(st, AT91_ADC_SR);
+
+	if (!(status & AT91_ADC_DRDY))
+		return IRQ_HANDLED;
+
+	if (status & st->channels_mask) {
+		st->done = true;
+		st->last_value = at91_adc_reg_read(st, AT91_ADC_LCDR);
+	}
+
+	wake_up_interruptible(&st->wq_data_avail);
+
+	return IRQ_HANDLED;
+}
+
+static int at91_adc_channel_init(struct iio_dev *idev,
+				 struct at91_adc_data *pdata)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	struct iio_chan_spec *chan_array;
+	int bit, idx = 0;
+
+	idev->num_channels = bitmap_weight(&pdata->channels_used,
+					   st->desc->num_channels);
+	chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
+			     GFP_KERNEL);
+
+	if (chan_array == NULL)
+		return -ENOMEM;
+
+	for_each_set_bit(bit, &pdata->channels_used, st->desc->num_channels) {
+		struct iio_chan_spec *chan = chan_array + idx;
+		chan->type = IIO_VOLTAGE;
+		chan->indexed = 1;
+		chan->channel = bit;
+		chan->scan_type.sign = 'u';
+		chan->scan_type.realbits = 10;
+		chan->scan_type.storagebits = 16;
+		chan->info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT;
+		idx++;
+	}
+
+	idev->channels = chan_array;
+	return idev->num_channels;
+}
+
+static void at91_adc_channel_remove(struct iio_dev *idev)
+{
+	kfree(idev->channels);
+}
+
+static int at91_adc_read_raw(struct iio_dev *idev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	int ret;
+
+	switch (mask) {
+	case 0:
+		mutex_lock(&st->lock);
+
+		at91_adc_reg_write(st, AT91_ADC_CHER,
+				  AT91_ADC_CH(chan->channel));
+		at91_adc_reg_write(st, AT91_ADC_IER,
+				  AT91_ADC_EOC(chan->channel));
+		at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_START);
+
+		ret = wait_event_interruptible_timeout(st->wq_data_avail,
+						       st->done,
+						       msecs_to_jiffies(1000));
+		if (ret == 0)
+			return -ETIMEDOUT;
+		else if (ret < 0)
+			return ret;
+
+		*val = st->last_value;
+
+		at91_adc_reg_write(st, AT91_ADC_CHDR,
+				  AT91_ADC_CH(chan->channel));
+		at91_adc_reg_write(st, AT91_ADC_IDR,
+				  AT91_ADC_EOC(chan->channel));
+
+		st->last_value = 0;
+		st->done = false;
+		mutex_unlock(&st->lock);
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = (st->vref_mv * 1000) >> chan->scan_type.realbits;
+		*val2 = 0;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_info at91_adc_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &at91_adc_read_raw,
+};
+
+static int __devinit at91_adc_probe(struct platform_device *pdev)
+{
+	unsigned int prsc, mstrclk, ticks;
+	int ret;
+	struct iio_dev *idev;
+	struct at91_adc_state *st;
+	struct resource *res;
+	struct at91_adc_data *pdata = pdev->dev.platform_data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "No resource defined\n");
+		ret = -ENXIO;
+		goto error_ret;
+	}
+
+	idev = iio_allocate_device(sizeof(struct at91_adc_state));
+	if (idev == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	platform_set_drvdata(pdev, idev);
+
+	idev->dev.parent = &pdev->dev;
+	idev->name = dev_name(&pdev->dev);
+	idev->modes = INDIO_DIRECT_MODE;
+	idev->info = &at91_adc_info;
+
+	st = iio_priv(idev);
+	ret = at91_adc_select_soc(st);
+	if (ret) {
+		dev_err(&pdev->dev, "SoC unknown\n");
+		goto error_free_device;
+	}
+
+	st->irq = platform_get_irq(pdev, 0);
+	if (st->irq < 0) {
+		dev_err(&pdev->dev, "No IRQ ID is designated\n");
+		ret = -ENODEV;
+		goto error_free_device;
+	}
+
+	if (!request_mem_region(res->start, resource_size(res),
+				"AT91 adc registers")) {
+		dev_err(&pdev->dev, "Resources are unavailable.\n");
+		ret = -EBUSY;
+		goto error_free_device;
+	}
+
+	st->reg_base = ioremap(res->start, resource_size(res));
+	if (!st->reg_base) {
+		dev_err(&pdev->dev, "Failed to map registers.\n");
+		ret = -ENOMEM;
+		goto error_release_mem;
+	}
+
+	/*
+	 * Disable all IRQs before setting up the handler
+	 */
+	at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_SWRST);
+	at91_adc_reg_write(st, AT91_ADC_IDR, 0xFFFFFFFF);
+	ret = request_irq(st->irq,
+			  at91_adc_eoc_trigger,
+			  0,
+			  pdev->dev.driver->name,
+			  idev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
+		goto error_unmap_reg;
+	}
+
+	st->clk = clk_get(&pdev->dev, st->desc->clock_name);
+	if (IS_ERR(st->clk)) {
+		dev_err(&pdev->dev, "Failed to get the clock.\n");
+		ret = PTR_ERR(st->clk);
+		goto error_free_irq;
+	}
+
+	clk_enable(st->clk);
+	mstrclk = clk_get_rate(st->clk);
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform data available.\n");
+		ret = -EINVAL;
+		goto error_free_clk;
+	}
+
+	if (!st->desc->clock) {
+		dev_err(&pdev->dev, "No ADCClock available.\n");
+		ret = -EINVAL;
+		goto error_free_clk;
+	}
+
+	/*
+	 * Prescaler rate computation using the formula from the Atmel's
+	 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
+	 * specified by the electrical characteristics of the board.
+	 */
+	prsc = (mstrclk / (2 * st->desc->clock)) - 1;
+
+	if (!st->desc->startup_time) {
+		dev_err(&pdev->dev, "No startup time available.\n");
+		ret = -EINVAL;
+		goto error_free_clk;
+	}
+
+	/*
+	 * Number of ticks needed to cover the startup time of the ADC as
+	 * defined in the electrical characteristics of the board, divided by 8.
+	 * The formula thus is : Startup Time = (ticks + 1) * 8 / ADC Clock
+	 */
+	ticks = round_up((st->desc->startup_time * st->desc->clock /
+			  1000000) - 1, 8) / 8;
+	at91_adc_reg_write(st, AT91_ADC_MR,
+			  (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
+			  (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
+
+	/* Setup the ADC channels available on the board */
+	ret = at91_adc_channel_init(idev, pdata);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
+		goto error_free_clk;
+	}
+
+	init_waitqueue_head(&st->wq_data_avail);
+	mutex_init(&st->lock);
+
+	st->vref_mv = pdata->vref;
+	st->channels_mask = pdata->channels_used;
+
+	ret = iio_device_register(idev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't register the device.\n");
+		goto error_free_channels;
+	}
+
+	return 0;
+
+error_free_channels:
+	at91_adc_channel_remove(idev);
+error_free_clk:
+	clk_disable(st->clk);
+	clk_put(st->clk);
+error_free_irq:
+	free_irq(st->irq, idev);
+error_unmap_reg:
+	iounmap(st->reg_base);
+error_release_mem:
+	release_mem_region(res->start, resource_size(res));
+error_free_device:
+	iio_free_device(idev);
+error_ret:
+	return ret;
+}
+
+static int __devexit at91_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *idev = platform_get_drvdata(pdev);
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	struct at91_adc_state *st = iio_priv(idev);
+
+	iio_device_unregister(idev);
+	at91_adc_channel_remove(idev);
+	clk_disable(st->clk);
+	clk_put(st->clk);
+	free_irq(st->irq, idev);
+	iounmap(st->reg_base);
+	release_mem_region(res->start, resource_size(res));
+	iio_free_device(idev);
+
+	return 0;
+}
+
+static struct platform_driver at91_adc_driver = {
+	.probe = at91_adc_probe,
+	.remove = __devexit_p(at91_adc_remove),
+	.driver = {
+		   .name = "at91_adc",
+	},
+};
+
+module_platform_driver(at91_adc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
-- 
1.7.5.4

Re: [PATCH 2/5] ARM: AT91: IIO: Add AT91 ADC driver.

[Jean-Christophe PLAGNIOL-VILLARD]

On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
> Add the IIO driver for the AT91 ADCs. It only supports and has
> been tested on the SAM9G20 evaluation boards, but support for
> other boards will come eventually.
> 
> This ADC is a multi-channel ADC with support for both hardware
> and software triggers.
> 
> This first version only supports software triggers.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Jonathan Cameron <jic23@cam.ac.uk>
> ---
>  drivers/staging/iio/adc/Kconfig    |    6 +
>  drivers/staging/iio/adc/Makefile   |    1 +
>  drivers/staging/iio/adc/at91_adc.c |  382 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 389 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/staging/iio/adc/at91_adc.c
> 
> diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
> index 592eabd..1494838 100644
> --- a/drivers/staging/iio/adc/Kconfig
> +++ b/drivers/staging/iio/adc/Kconfig
> @@ -169,6 +169,12 @@ config AD7280
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called ad7280a
>  
> +config AT91_ADC
> +	tristate "Atmel AT91 ADC"
> +	depends on SYSFS && ARCH_AT91
> +	help
> +	  Say yes here to build support for Atmel AT91 ADC.
> +
>  config MAX1363
>  	tristate "Maxim max1363 ADC driver"
>  	depends on I2C
> diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
> index f83ab95..8cb6d1c 100644
> --- a/drivers/staging/iio/adc/Makefile
> +++ b/drivers/staging/iio/adc/Makefile
> @@ -38,3 +38,4 @@ obj-$(CONFIG_ADT7310) += adt7310.o
>  obj-$(CONFIG_ADT7410) += adt7410.o
>  obj-$(CONFIG_AD7280) += ad7280a.o
>  obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
> +obj-$(CONFIG_AT91_ADC) += at91_adc.o
> diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
> new file mode 100644
> index 0000000..c76516a
> --- /dev/null
> +++ b/drivers/staging/iio/adc/at91_adc.c
> @@ -0,0 +1,382 @@
> +/*
> + * Driver for the ADC present in the Atmel AT91 evaluation boards.
> + *
> + * Copyright 2011 Free Electrons
> + *
> + * Licensed under the GPLv2 or later.
> + */
> +
> +#include <linux/bitmap.h>
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/jiffies.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/wait.h>
> +
> +#include "../iio.h"
> +#include <linux/platform_data/at91_adc.h>
> +
> +#include <mach/at91_adc.h>
> +#include <mach/cpu.h>
> +
> +/**
> + * struct at91_adc_desc - description of the ADC on the board
> + * @clock:		ADC clock as specified by the datasheet, in Hz.
> + * @clock_name		Name of the ADC clock as defined in the clock tree
> + * @num_channels:	global number of channels available on the board (to
> +			specify which channels are indeed in use on the
> +			board, see the channels_used bitmask in the platform
> +			data)
> + * @startup_time:	startup time of the ADC in microseconds
> + */
> +struct at91_adc_desc {
> +	u32			clock;
> +	char			*clock_name;
> +	u8			num_channels;
> +	u8			startup_time;
> +};
> +
> +struct at91_adc_state {
> +	unsigned long		channels_mask;
> +	struct clk		*clk;
> +	bool			done;
> +	struct at91_adc_desc	*desc;
> +	int			irq;
> +	u16			last_value;
> +	struct mutex		lock;
> +	void __iomem		*reg_base;
> +	u32			vref_mv;
> +	wait_queue_head_t	wq_data_avail;
> +};
> +
> +static struct at91_adc_desc at91_adc_desc_sam9g20 = {
> +	.clock = 5000000,
why 5Mhz?
> +	.clock_name = "adc_clk",
> +	.num_channels = 4,
> +	.startup_time = 10,
> +};
> +
this is soc specific nedd to be in the soc not in the driver
> +static int at91_adc_select_soc(struct at91_adc_state *st)
> +{
> +	if (cpu_is_at91sam9g20()) {
> +		st->desc = &at91_adc_desc_sam9g20;
> +		return 0;
> +	}
> +
> +	return -ENODEV;
> +}
ditto
> +

> +
> +static int __devinit at91_adc_probe(struct platform_device *pdev)
> +{
> +	unsigned int prsc, mstrclk, ticks;
> +	int ret;
> +	struct iio_dev *idev;
> +	struct at91_adc_state *st;
> +	struct resource *res;
> +	struct at91_adc_data *pdata = pdev->dev.platform_data;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(&pdev->dev, "No resource defined\n");
> +		ret = -ENXIO;
> +		goto error_ret;
> +	}
> +
> +	idev = iio_allocate_device(sizeof(struct at91_adc_state));
> +	if (idev == NULL) {
> +		ret = -ENOMEM;
> +		goto error_ret;
> +	}
> +
> +	platform_set_drvdata(pdev, idev);
> +
> +	idev->dev.parent = &pdev->dev;
> +	idev->name = dev_name(&pdev->dev);
> +	idev->modes = INDIO_DIRECT_MODE;
> +	idev->info = &at91_adc_info;
> +
> +	st = iio_priv(idev);
> +	ret = at91_adc_select_soc(st);
> +	if (ret) {
> +		dev_err(&pdev->dev, "SoC unknown\n");
> +		goto error_free_device;
> +	}
> +
> +	st->irq = platform_get_irq(pdev, 0);
> +	if (st->irq < 0) {
> +		dev_err(&pdev->dev, "No IRQ ID is designated\n");
> +		ret = -ENODEV;
> +		goto error_free_device;
> +	}
> +
> +	if (!request_mem_region(res->start, resource_size(res),
> +				"AT91 adc registers")) {
> +		dev_err(&pdev->dev, "Resources are unavailable.\n");
> +		ret = -EBUSY;
> +		goto error_free_device;
> +	}
> +
> +	st->reg_base = ioremap(res->start, resource_size(res));
> +	if (!st->reg_base) {
> +		dev_err(&pdev->dev, "Failed to map registers.\n");
> +		ret = -ENOMEM;
> +		goto error_release_mem;
> +	}
> +
> +	/*
> +	 * Disable all IRQs before setting up the handler
> +	 */
> +	at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_SWRST);
> +	at91_adc_reg_write(st, AT91_ADC_IDR, 0xFFFFFFFF);
> +	ret = request_irq(st->irq,
> +			  at91_adc_eoc_trigger,
> +			  0,
> +			  pdev->dev.driver->name,
> +			  idev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
> +		goto error_unmap_reg;
> +	}
> +
> +	st->clk = clk_get(&pdev->dev, st->desc->clock_name);
use a fixed clock name
> +	if (IS_ERR(st->clk)) {
> +		dev_err(&pdev->dev, "Failed to get the clock.\n");
> +		ret = PTR_ERR(st->clk);
> +		goto error_free_irq;
> +	}
> +
use clk_prepare & co
> +	clk_enable(st->clk);
> +	mstrclk = clk_get_rate(st->clk);
> +
> +	if (!pdata) {
> +		dev_err(&pdev->dev, "No platform data available.\n");
> +		ret = -EINVAL;
> +		goto error_free_clk;
> +	}
need to be check first

Best Regards,
J.

[PATCH 2/5] ARM: AT91: IIO: Add AT91 ADC driver.

[Jean-Christophe PLAGNIOL-VILLARD]

On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
> Add the IIO driver for the AT91 ADCs. It only supports and has
> been tested on the SAM9G20 evaluation boards, but support for
> other boards will come eventually.
> 
> This ADC is a multi-channel ADC with support for both hardware
> and software triggers.
> 
> This first version only supports software triggers.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Jonathan Cameron <jic23@cam.ac.uk>
> ---
>  drivers/staging/iio/adc/Kconfig    |    6 +
>  drivers/staging/iio/adc/Makefile   |    1 +
>  drivers/staging/iio/adc/at91_adc.c |  382 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 389 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/staging/iio/adc/at91_adc.c
> 
> diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
> index 592eabd..1494838 100644
> --- a/drivers/staging/iio/adc/Kconfig
> +++ b/drivers/staging/iio/adc/Kconfig
> @@ -169,6 +169,12 @@ config AD7280
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called ad7280a
>  
> +config AT91_ADC
> +	tristate "Atmel AT91 ADC"
> +	depends on SYSFS && ARCH_AT91
> +	help
> +	  Say yes here to build support for Atmel AT91 ADC.
> +
>  config MAX1363
>  	tristate "Maxim max1363 ADC driver"
>  	depends on I2C
> diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
> index f83ab95..8cb6d1c 100644
> --- a/drivers/staging/iio/adc/Makefile
> +++ b/drivers/staging/iio/adc/Makefile
> @@ -38,3 +38,4 @@ obj-$(CONFIG_ADT7310) += adt7310.o
>  obj-$(CONFIG_ADT7410) += adt7410.o
>  obj-$(CONFIG_AD7280) += ad7280a.o
>  obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
> +obj-$(CONFIG_AT91_ADC) += at91_adc.o
> diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
> new file mode 100644
> index 0000000..c76516a
> --- /dev/null
> +++ b/drivers/staging/iio/adc/at91_adc.c
> @@ -0,0 +1,382 @@
> +/*
> + * Driver for the ADC present in the Atmel AT91 evaluation boards.
> + *
> + * Copyright 2011 Free Electrons
> + *
> + * Licensed under the GPLv2 or later.
> + */
> +
> +#include <linux/bitmap.h>
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/jiffies.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/wait.h>
> +
> +#include "../iio.h"
> +#include <linux/platform_data/at91_adc.h>
> +
> +#include <mach/at91_adc.h>
> +#include <mach/cpu.h>
> +
> +/**
> + * struct at91_adc_desc - description of the ADC on the board
> + * @clock:		ADC clock as specified by the datasheet, in Hz.
> + * @clock_name		Name of the ADC clock as defined in the clock tree
> + * @num_channels:	global number of channels available on the board (to
> +			specify which channels are indeed in use on the
> +			board, see the channels_used bitmask in the platform
> +			data)
> + * @startup_time:	startup time of the ADC in microseconds
> + */
> +struct at91_adc_desc {
> +	u32			clock;
> +	char			*clock_name;
> +	u8			num_channels;
> +	u8			startup_time;
> +};
> +
> +struct at91_adc_state {
> +	unsigned long		channels_mask;
> +	struct clk		*clk;
> +	bool			done;
> +	struct at91_adc_desc	*desc;
> +	int			irq;
> +	u16			last_value;
> +	struct mutex		lock;
> +	void __iomem		*reg_base;
> +	u32			vref_mv;
> +	wait_queue_head_t	wq_data_avail;
> +};
> +
> +static struct at91_adc_desc at91_adc_desc_sam9g20 = {
> +	.clock = 5000000,
why 5Mhz?
> +	.clock_name = "adc_clk",
> +	.num_channels = 4,
> +	.startup_time = 10,
> +};
> +
this is soc specific nedd to be in the soc not in the driver
> +static int at91_adc_select_soc(struct at91_adc_state *st)
> +{
> +	if (cpu_is_at91sam9g20()) {
> +		st->desc = &at91_adc_desc_sam9g20;
> +		return 0;
> +	}
> +
> +	return -ENODEV;
> +}
ditto
> +

> +
> +static int __devinit at91_adc_probe(struct platform_device *pdev)
> +{
> +	unsigned int prsc, mstrclk, ticks;
> +	int ret;
> +	struct iio_dev *idev;
> +	struct at91_adc_state *st;
> +	struct resource *res;
> +	struct at91_adc_data *pdata = pdev->dev.platform_data;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(&pdev->dev, "No resource defined\n");
> +		ret = -ENXIO;
> +		goto error_ret;
> +	}
> +
> +	idev = iio_allocate_device(sizeof(struct at91_adc_state));
> +	if (idev == NULL) {
> +		ret = -ENOMEM;
> +		goto error_ret;
> +	}
> +
> +	platform_set_drvdata(pdev, idev);
> +
> +	idev->dev.parent = &pdev->dev;
> +	idev->name = dev_name(&pdev->dev);
> +	idev->modes = INDIO_DIRECT_MODE;
> +	idev->info = &at91_adc_info;
> +
> +	st = iio_priv(idev);
> +	ret = at91_adc_select_soc(st);
> +	if (ret) {
> +		dev_err(&pdev->dev, "SoC unknown\n");
> +		goto error_free_device;
> +	}
> +
> +	st->irq = platform_get_irq(pdev, 0);
> +	if (st->irq < 0) {
> +		dev_err(&pdev->dev, "No IRQ ID is designated\n");
> +		ret = -ENODEV;
> +		goto error_free_device;
> +	}
> +
> +	if (!request_mem_region(res->start, resource_size(res),
> +				"AT91 adc registers")) {
> +		dev_err(&pdev->dev, "Resources are unavailable.\n");
> +		ret = -EBUSY;
> +		goto error_free_device;
> +	}
> +
> +	st->reg_base = ioremap(res->start, resource_size(res));
> +	if (!st->reg_base) {
> +		dev_err(&pdev->dev, "Failed to map registers.\n");
> +		ret = -ENOMEM;
> +		goto error_release_mem;
> +	}
> +
> +	/*
> +	 * Disable all IRQs before setting up the handler
> +	 */
> +	at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_SWRST);
> +	at91_adc_reg_write(st, AT91_ADC_IDR, 0xFFFFFFFF);
> +	ret = request_irq(st->irq,
> +			  at91_adc_eoc_trigger,
> +			  0,
> +			  pdev->dev.driver->name,
> +			  idev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
> +		goto error_unmap_reg;
> +	}
> +
> +	st->clk = clk_get(&pdev->dev, st->desc->clock_name);
use a fixed clock name
> +	if (IS_ERR(st->clk)) {
> +		dev_err(&pdev->dev, "Failed to get the clock.\n");
> +		ret = PTR_ERR(st->clk);
> +		goto error_free_irq;
> +	}
> +
use clk_prepare & co
> +	clk_enable(st->clk);
> +	mstrclk = clk_get_rate(st->clk);
> +
> +	if (!pdata) {
> +		dev_err(&pdev->dev, "No platform data available.\n");
> +		ret = -EINVAL;
> +		goto error_free_clk;
> +	}
need to be check first

Best Regards,
J.

Re: [PATCH 2/5] ARM: AT91: IIO: Add AT91 ADC driver.

[Maxime Ripard]

Hi,

Le 07/04/2012 05:27, Jean-Christophe PLAGNIOL-VILLARD a =E9crit :
> On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
>> Add the IIO driver for the AT91 ADCs. It only supports and has
>> been tested on the SAM9G20 evaluation boards, but support for
>> other boards will come eventually.
>>
>> This ADC is a multi-channel ADC with support for both hardware
>> and software triggers.
>>
>> This first version only supports software triggers.
>>
>> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>
>> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
>> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
>> Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
>> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
>> Cc: Jonathan Cameron <jic23@cam.ac.uk>
>> ---
>>  drivers/staging/iio/adc/Kconfig    |    6 +
>>  drivers/staging/iio/adc/Makefile   |    1 +
>>  drivers/staging/iio/adc/at91_adc.c |  382 +++++++++++++++++++++++++++=
+++++++++
>>  3 files changed, 389 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/staging/iio/adc/at91_adc.c
>>
>> diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc=
/Kconfig
>> index 592eabd..1494838 100644
>> --- a/drivers/staging/iio/adc/Kconfig
>> +++ b/drivers/staging/iio/adc/Kconfig
>> @@ -169,6 +169,12 @@ config AD7280
>>  	  To compile this driver as a module, choose M here: the
>>  	  module will be called ad7280a
>> =20
>> +config AT91_ADC
>> +	tristate "Atmel AT91 ADC"
>> +	depends on SYSFS && ARCH_AT91
>> +	help
>> +	  Say yes here to build support for Atmel AT91 ADC.
>> +
>>  config MAX1363
>>  	tristate "Maxim max1363 ADC driver"
>>  	depends on I2C
>> diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/ad=
c/Makefile
>> index f83ab95..8cb6d1c 100644
>> --- a/drivers/staging/iio/adc/Makefile
>> +++ b/drivers/staging/iio/adc/Makefile
>> @@ -38,3 +38,4 @@ obj-$(CONFIG_ADT7310) +=3D adt7310.o
>>  obj-$(CONFIG_ADT7410) +=3D adt7410.o
>>  obj-$(CONFIG_AD7280) +=3D ad7280a.o
>>  obj-$(CONFIG_LPC32XX_ADC) +=3D lpc32xx_adc.o
>> +obj-$(CONFIG_AT91_ADC) +=3D at91_adc.o
>> diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/=
adc/at91_adc.c
>> new file mode 100644
>> index 0000000..c76516a
>> --- /dev/null
>> +++ b/drivers/staging/iio/adc/at91_adc.c
>> @@ -0,0 +1,382 @@
>> +/*
>> + * Driver for the ADC present in the Atmel AT91 evaluation boards.
>> + *
>> + * Copyright 2011 Free Electrons
>> + *
>> + * Licensed under the GPLv2 or later.
>> + */
>> +
>> +#include <linux/bitmap.h>
>> +#include <linux/bitops.h>
>> +#include <linux/clk.h>
>> +#include <linux/err.h>
>> +#include <linux/io.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/jiffies.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/sched.h>
>> +#include <linux/slab.h>
>> +#include <linux/wait.h>
>> +
>> +#include "../iio.h"
>> +#include <linux/platform_data/at91_adc.h>
>> +
>> +#include <mach/at91_adc.h>
>> +#include <mach/cpu.h>
>> +
>> +/**
>> + * struct at91_adc_desc - description of the ADC on the board
>> + * @clock:		ADC clock as specified by the datasheet, in Hz.
>> + * @clock_name		Name of the ADC clock as defined in the clock tree
>> + * @num_channels:	global number of channels available on the board (t=
o
>> +			specify which channels are indeed in use on the
>> +			board, see the channels_used bitmask in the platform
>> +			data)
>> + * @startup_time:	startup time of the ADC in microseconds
>> + */
>> +struct at91_adc_desc {
>> +	u32			clock;
>> +	char			*clock_name;
>> +	u8			num_channels;
>> +	u8			startup_time;
>> +};
>> +
>> +struct at91_adc_state {
>> +	unsigned long		channels_mask;
>> +	struct clk		*clk;
>> +	bool			done;
>> +	struct at91_adc_desc	*desc;
>> +	int			irq;
>> +	u16			last_value;
>> +	struct mutex		lock;
>> +	void __iomem		*reg_base;
>> +	u32			vref_mv;
>> +	wait_queue_head_t	wq_data_avail;
>> +};
>> +
>> +static struct at91_adc_desc at91_adc_desc_sam9g20 =3D {
>> +	.clock =3D 5000000,
> why 5Mhz?

This is the value given by the datasheet of the G20 SoC.

>> +	.clock_name =3D "adc_clk",
>> +	.num_channels =3D 4,
>> +	.startup_time =3D 10,
>> +};
>> +
> this is soc specific nedd to be in the soc not in the driver

Some time ago, Nicolas Ferre asked me to move the SoC specific part to
the driver, mostly because of two things:
  * *_devices.c files were suppose to disappear with the DT
  * Triggers are not all supported by the driver, so only the driver
knows which triggers it can expose (pen-down or periodic triggers for
the G45 are not supported for example). This can't be done through the
SoC files.

>> +static int at91_adc_select_soc(struct at91_adc_state *st)
>> +{
>> +	if (cpu_is_at91sam9g20()) {
>> +		st->desc =3D &at91_adc_desc_sam9g20;
>> +		return 0;
>> +	}
>> +
>> +	return -ENODEV;
>> +}
> ditto
>> +
>=20
>> +
>> +static int __devinit at91_adc_probe(struct platform_device *pdev)
>> +{
>> +	unsigned int prsc, mstrclk, ticks;
>> +	int ret;
>> +	struct iio_dev *idev;
>> +	struct at91_adc_state *st;
>> +	struct resource *res;
>> +	struct at91_adc_data *pdata =3D pdev->dev.platform_data;
>> +
>> +	res =3D platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	if (!res) {
>> +		dev_err(&pdev->dev, "No resource defined\n");
>> +		ret =3D -ENXIO;
>> +		goto error_ret;
>> +	}
>> +
>> +	idev =3D iio_allocate_device(sizeof(struct at91_adc_state));
>> +	if (idev =3D=3D NULL) {
>> +		ret =3D -ENOMEM;
>> +		goto error_ret;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, idev);
>> +
>> +	idev->dev.parent =3D &pdev->dev;
>> +	idev->name =3D dev_name(&pdev->dev);
>> +	idev->modes =3D INDIO_DIRECT_MODE;
>> +	idev->info =3D &at91_adc_info;
>> +
>> +	st =3D iio_priv(idev);
>> +	ret =3D at91_adc_select_soc(st);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "SoC unknown\n");
>> +		goto error_free_device;
>> +	}
>> +
>> +	st->irq =3D platform_get_irq(pdev, 0);
>> +	if (st->irq < 0) {
>> +		dev_err(&pdev->dev, "No IRQ ID is designated\n");
>> +		ret =3D -ENODEV;
>> +		goto error_free_device;
>> +	}
>> +
>> +	if (!request_mem_region(res->start, resource_size(res),
>> +				"AT91 adc registers")) {
>> +		dev_err(&pdev->dev, "Resources are unavailable.\n");
>> +		ret =3D -EBUSY;
>> +		goto error_free_device;
>> +	}
>> +
>> +	st->reg_base =3D ioremap(res->start, resource_size(res));
>> +	if (!st->reg_base) {
>> +		dev_err(&pdev->dev, "Failed to map registers.\n");
>> +		ret =3D -ENOMEM;
>> +		goto error_release_mem;
>> +	}
>> +
>> +	/*
>> +	 * Disable all IRQs before setting up the handler
>> +	 */
>> +	at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_SWRST);
>> +	at91_adc_reg_write(st, AT91_ADC_IDR, 0xFFFFFFFF);
>> +	ret =3D request_irq(st->irq,
>> +			  at91_adc_eoc_trigger,
>> +			  0,
>> +			  pdev->dev.driver->name,
>> +			  idev);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
>> +		goto error_unmap_reg;
>> +	}
>> +
>> +	st->clk =3D clk_get(&pdev->dev, st->desc->clock_name);
> use a fixed clock name

I can't. The clock name is "adc_clk" for the G20, "tsc_clk" for the G45.

>> +	if (IS_ERR(st->clk)) {
>> +		dev_err(&pdev->dev, "Failed to get the clock.\n");
>> +		ret =3D PTR_ERR(st->clk);
>> +		goto error_free_irq;
>> +	}
>> +
> use clk_prepare & co

Ok, I will look into this.

>> +	clk_enable(st->clk);
>> +	mstrclk =3D clk_get_rate(st->clk);
>> +
>> +	if (!pdata) {
>> +		dev_err(&pdev->dev, "No platform data available.\n");
>> +		ret =3D -EINVAL;
>> +		goto error_free_clk;
>> +	}
> need to be check first

Ok

Thanks,
Maxime

--=20
Maxime Ripard, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH 2/5] ARM: AT91: IIO: Add AT91 ADC driver.

[Maxime Ripard]

Hi,

Le 07/04/2012 05:27, Jean-Christophe PLAGNIOL-VILLARD a ?crit :
> On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
>> Add the IIO driver for the AT91 ADCs. It only supports and has
>> been tested on the SAM9G20 evaluation boards, but support for
>> other boards will come eventually.
>>
>> This ADC is a multi-channel ADC with support for both hardware
>> and software triggers.
>>
>> This first version only supports software triggers.
>>
>> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>
>> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
>> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
>> Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
>> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
>> Cc: Jonathan Cameron <jic23@cam.ac.uk>
>> ---
>>  drivers/staging/iio/adc/Kconfig    |    6 +
>>  drivers/staging/iio/adc/Makefile   |    1 +
>>  drivers/staging/iio/adc/at91_adc.c |  382 ++++++++++++++++++++++++++++++++++++
>>  3 files changed, 389 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/staging/iio/adc/at91_adc.c
>>
>> diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
>> index 592eabd..1494838 100644
>> --- a/drivers/staging/iio/adc/Kconfig
>> +++ b/drivers/staging/iio/adc/Kconfig
>> @@ -169,6 +169,12 @@ config AD7280
>>  	  To compile this driver as a module, choose M here: the
>>  	  module will be called ad7280a
>>  
>> +config AT91_ADC
>> +	tristate "Atmel AT91 ADC"
>> +	depends on SYSFS && ARCH_AT91
>> +	help
>> +	  Say yes here to build support for Atmel AT91 ADC.
>> +
>>  config MAX1363
>>  	tristate "Maxim max1363 ADC driver"
>>  	depends on I2C
>> diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
>> index f83ab95..8cb6d1c 100644
>> --- a/drivers/staging/iio/adc/Makefile
>> +++ b/drivers/staging/iio/adc/Makefile
>> @@ -38,3 +38,4 @@ obj-$(CONFIG_ADT7310) += adt7310.o
>>  obj-$(CONFIG_ADT7410) += adt7410.o
>>  obj-$(CONFIG_AD7280) += ad7280a.o
>>  obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
>> +obj-$(CONFIG_AT91_ADC) += at91_adc.o
>> diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
>> new file mode 100644
>> index 0000000..c76516a
>> --- /dev/null
>> +++ b/drivers/staging/iio/adc/at91_adc.c
>> @@ -0,0 +1,382 @@
>> +/*
>> + * Driver for the ADC present in the Atmel AT91 evaluation boards.
>> + *
>> + * Copyright 2011 Free Electrons
>> + *
>> + * Licensed under the GPLv2 or later.
>> + */
>> +
>> +#include <linux/bitmap.h>
>> +#include <linux/bitops.h>
>> +#include <linux/clk.h>
>> +#include <linux/err.h>
>> +#include <linux/io.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/jiffies.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/sched.h>
>> +#include <linux/slab.h>
>> +#include <linux/wait.h>
>> +
>> +#include "../iio.h"
>> +#include <linux/platform_data/at91_adc.h>
>> +
>> +#include <mach/at91_adc.h>
>> +#include <mach/cpu.h>
>> +
>> +/**
>> + * struct at91_adc_desc - description of the ADC on the board
>> + * @clock:		ADC clock as specified by the datasheet, in Hz.
>> + * @clock_name		Name of the ADC clock as defined in the clock tree
>> + * @num_channels:	global number of channels available on the board (to
>> +			specify which channels are indeed in use on the
>> +			board, see the channels_used bitmask in the platform
>> +			data)
>> + * @startup_time:	startup time of the ADC in microseconds
>> + */
>> +struct at91_adc_desc {
>> +	u32			clock;
>> +	char			*clock_name;
>> +	u8			num_channels;
>> +	u8			startup_time;
>> +};
>> +
>> +struct at91_adc_state {
>> +	unsigned long		channels_mask;
>> +	struct clk		*clk;
>> +	bool			done;
>> +	struct at91_adc_desc	*desc;
>> +	int			irq;
>> +	u16			last_value;
>> +	struct mutex		lock;
>> +	void __iomem		*reg_base;
>> +	u32			vref_mv;
>> +	wait_queue_head_t	wq_data_avail;
>> +};
>> +
>> +static struct at91_adc_desc at91_adc_desc_sam9g20 = {
>> +	.clock = 5000000,
> why 5Mhz?

This is the value given by the datasheet of the G20 SoC.

>> +	.clock_name = "adc_clk",
>> +	.num_channels = 4,
>> +	.startup_time = 10,
>> +};
>> +
> this is soc specific nedd to be in the soc not in the driver

Some time ago, Nicolas Ferre asked me to move the SoC specific part to
the driver, mostly because of two things:
  * *_devices.c files were suppose to disappear with the DT
  * Triggers are not all supported by the driver, so only the driver
knows which triggers it can expose (pen-down or periodic triggers for
the G45 are not supported for example). This can't be done through the
SoC files.

>> +static int at91_adc_select_soc(struct at91_adc_state *st)
>> +{
>> +	if (cpu_is_at91sam9g20()) {
>> +		st->desc = &at91_adc_desc_sam9g20;
>> +		return 0;
>> +	}
>> +
>> +	return -ENODEV;
>> +}
> ditto
>> +
> 
>> +
>> +static int __devinit at91_adc_probe(struct platform_device *pdev)
>> +{
>> +	unsigned int prsc, mstrclk, ticks;
>> +	int ret;
>> +	struct iio_dev *idev;
>> +	struct at91_adc_state *st;
>> +	struct resource *res;
>> +	struct at91_adc_data *pdata = pdev->dev.platform_data;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	if (!res) {
>> +		dev_err(&pdev->dev, "No resource defined\n");
>> +		ret = -ENXIO;
>> +		goto error_ret;
>> +	}
>> +
>> +	idev = iio_allocate_device(sizeof(struct at91_adc_state));
>> +	if (idev == NULL) {
>> +		ret = -ENOMEM;
>> +		goto error_ret;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, idev);
>> +
>> +	idev->dev.parent = &pdev->dev;
>> +	idev->name = dev_name(&pdev->dev);
>> +	idev->modes = INDIO_DIRECT_MODE;
>> +	idev->info = &at91_adc_info;
>> +
>> +	st = iio_priv(idev);
>> +	ret = at91_adc_select_soc(st);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "SoC unknown\n");
>> +		goto error_free_device;
>> +	}
>> +
>> +	st->irq = platform_get_irq(pdev, 0);
>> +	if (st->irq < 0) {
>> +		dev_err(&pdev->dev, "No IRQ ID is designated\n");
>> +		ret = -ENODEV;
>> +		goto error_free_device;
>> +	}
>> +
>> +	if (!request_mem_region(res->start, resource_size(res),
>> +				"AT91 adc registers")) {
>> +		dev_err(&pdev->dev, "Resources are unavailable.\n");
>> +		ret = -EBUSY;
>> +		goto error_free_device;
>> +	}
>> +
>> +	st->reg_base = ioremap(res->start, resource_size(res));
>> +	if (!st->reg_base) {
>> +		dev_err(&pdev->dev, "Failed to map registers.\n");
>> +		ret = -ENOMEM;
>> +		goto error_release_mem;
>> +	}
>> +
>> +	/*
>> +	 * Disable all IRQs before setting up the handler
>> +	 */
>> +	at91_adc_reg_write(st, AT91_ADC_CR, AT91_ADC_SWRST);
>> +	at91_adc_reg_write(st, AT91_ADC_IDR, 0xFFFFFFFF);
>> +	ret = request_irq(st->irq,
>> +			  at91_adc_eoc_trigger,
>> +			  0,
>> +			  pdev->dev.driver->name,
>> +			  idev);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
>> +		goto error_unmap_reg;
>> +	}
>> +
>> +	st->clk = clk_get(&pdev->dev, st->desc->clock_name);
> use a fixed clock name

I can't. The clock name is "adc_clk" for the G20, "tsc_clk" for the G45.

>> +	if (IS_ERR(st->clk)) {
>> +		dev_err(&pdev->dev, "Failed to get the clock.\n");
>> +		ret = PTR_ERR(st->clk);
>> +		goto error_free_irq;
>> +	}
>> +
> use clk_prepare & co

Ok, I will look into this.

>> +	clk_enable(st->clk);
>> +	mstrclk = clk_get_rate(st->clk);
>> +
>> +	if (!pdata) {
>> +		dev_err(&pdev->dev, "No platform data available.\n");
>> +		ret = -EINVAL;
>> +		goto error_free_clk;
>> +	}
> need to be check first

Ok

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH 3/5] ARM: AT91: Add the ADC to the sam9g20ek board

[Maxime Ripard]

This patch adds platform data for the AT91 ADC driver support for
the AT91SAM9G20-EK board.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
---
 arch/arm/mach-at91/at91sam9260_devices.c |   53 ++++++++++++++++++++++++++++++
 arch/arm/mach-at91/board-sam9g20ek.c     |   13 +++++++
 2 files changed, 66 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index 7e5651e..08464fe 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -17,6 +17,8 @@
 #include <linux/platform_device.h>
 #include <linux/i2c-gpio.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/board.h>
 #include <mach/cpu.h>
 #include <mach/at91sam9260.h>
@@ -1366,6 +1368,57 @@ void __init at91_add_device_cf(struct at91_cf_data *data)
 void __init at91_add_device_cf(struct at91_cf_data * data) {}
 #endif
 
+/* --------------------------------------------------------------------
+ *  ADCs
+ * -------------------------------------------------------------------- */
+
+#if defined(CONFIG_AT91_ADC) || defined(CONFIG_AT91_ADC_MODULE)
+static struct at91_adc_data adc_data;
+
+static struct resource adc_resources[] = {
+	[0] = {
+		.start	= AT91SAM9260_BASE_ADC,
+		.end	= AT91SAM9260_BASE_ADC + SZ_16K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= AT91SAM9260_ID_ADC,
+		.end	= AT91SAM9260_ID_ADC,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct platform_device at91_adc_device = {
+	.name		= "at91_adc",
+	.id		= -1,
+	.dev		= {
+				.platform_data		= &adc_data,
+	},
+	.resource	= adc_resources,
+	.num_resources	= ARRAY_SIZE(adc_resources),
+};
+
+void __init at91_add_device_adc(struct at91_adc_data *data)
+{
+	if (!data)
+		return;
+
+	if (test_bit(0, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC0, 0);
+	if (test_bit(1, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC1, 0);
+	if (test_bit(2, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC2, 0);
+	if (test_bit(3, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC3, 0);
+
+	adc_data = *data;
+	platform_device_register(&at91_adc_device);
+}
+#else
+void __init at91_add_device_adc(struct at91_adc_data *data) {}
+#endif
+
 /* -------------------------------------------------------------------- */
 /*
  * These devices are always present and don't need any board-specific
diff --git a/arch/arm/mach-at91/board-sam9g20ek.c b/arch/arm/mach-at91/board-sam9g20ek.c
index 8923ec9..2ce4e26 100644
--- a/arch/arm/mach-at91/board-sam9g20ek.c
+++ b/arch/arm/mach-at91/board-sam9g20ek.c
@@ -32,6 +32,8 @@
 #include <linux/regulator/fixed.h>
 #include <linux/regulator/consumer.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/hardware.h>
 #include <asm/setup.h>
 #include <asm/mach-types.h>
@@ -318,6 +320,15 @@ static void __init ek_add_device_buttons(void)
 static void __init ek_add_device_buttons(void) {}
 #endif
 
+/*
+ * ADCs
+ */
+
+static struct at91_adc_data ek_adc_data = {
+	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3),
+	.vref = 3300,
+};
+
 #if defined(CONFIG_REGULATOR_FIXED_VOLTAGE) || defined(CONFIG_REGULATOR_FIXED_VOLTAGE_MODULE)
 static struct regulator_consumer_supply ek_audio_consumer_supplies[] = {
 	REGULATOR_SUPPLY("AVDD", "0-001b"),
@@ -393,6 +404,8 @@ static void __init ek_board_init(void)
 	ek_add_device_gpio_leds();
 	/* Push Buttons */
 	ek_add_device_buttons();
+	/* ADCs */
+	at91_add_device_adc(&ek_adc_data);
 	/* PCK0 provides MCLK to the WM8731 */
 	at91_set_B_periph(AT91_PIN_PC1, 0);
 	/* SSC (for WM8731) */
-- 
1.7.5.4

[PATCH 3/5] ARM: AT91: Add the ADC to the sam9g20ek board

[Maxime Ripard]

This patch adds platform data for the AT91 ADC driver support for
the AT91SAM9G20-EK board.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
---
 arch/arm/mach-at91/at91sam9260_devices.c |   53 ++++++++++++++++++++++++++++++
 arch/arm/mach-at91/board-sam9g20ek.c     |   13 +++++++
 2 files changed, 66 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index 7e5651e..08464fe 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -17,6 +17,8 @@
 #include <linux/platform_device.h>
 #include <linux/i2c-gpio.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/board.h>
 #include <mach/cpu.h>
 #include <mach/at91sam9260.h>
@@ -1366,6 +1368,57 @@ void __init at91_add_device_cf(struct at91_cf_data *data)
 void __init at91_add_device_cf(struct at91_cf_data * data) {}
 #endif
 
+/* --------------------------------------------------------------------
+ *  ADCs
+ * -------------------------------------------------------------------- */
+
+#if defined(CONFIG_AT91_ADC) || defined(CONFIG_AT91_ADC_MODULE)
+static struct at91_adc_data adc_data;
+
+static struct resource adc_resources[] = {
+	[0] = {
+		.start	= AT91SAM9260_BASE_ADC,
+		.end	= AT91SAM9260_BASE_ADC + SZ_16K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= AT91SAM9260_ID_ADC,
+		.end	= AT91SAM9260_ID_ADC,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct platform_device at91_adc_device = {
+	.name		= "at91_adc",
+	.id		= -1,
+	.dev		= {
+				.platform_data		= &adc_data,
+	},
+	.resource	= adc_resources,
+	.num_resources	= ARRAY_SIZE(adc_resources),
+};
+
+void __init at91_add_device_adc(struct at91_adc_data *data)
+{
+	if (!data)
+		return;
+
+	if (test_bit(0, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC0, 0);
+	if (test_bit(1, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC1, 0);
+	if (test_bit(2, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC2, 0);
+	if (test_bit(3, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC3, 0);
+
+	adc_data = *data;
+	platform_device_register(&at91_adc_device);
+}
+#else
+void __init at91_add_device_adc(struct at91_adc_data *data) {}
+#endif
+
 /* -------------------------------------------------------------------- */
 /*
  * These devices are always present and don't need any board-specific
diff --git a/arch/arm/mach-at91/board-sam9g20ek.c b/arch/arm/mach-at91/board-sam9g20ek.c
index 8923ec9..2ce4e26 100644
--- a/arch/arm/mach-at91/board-sam9g20ek.c
+++ b/arch/arm/mach-at91/board-sam9g20ek.c
@@ -32,6 +32,8 @@
 #include <linux/regulator/fixed.h>
 #include <linux/regulator/consumer.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/hardware.h>
 #include <asm/setup.h>
 #include <asm/mach-types.h>
@@ -318,6 +320,15 @@ static void __init ek_add_device_buttons(void)
 static void __init ek_add_device_buttons(void) {}
 #endif
 
+/*
+ * ADCs
+ */
+
+static struct at91_adc_data ek_adc_data = {
+	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3),
+	.vref = 3300,
+};
+
 #if defined(CONFIG_REGULATOR_FIXED_VOLTAGE) || defined(CONFIG_REGULATOR_FIXED_VOLTAGE_MODULE)
 static struct regulator_consumer_supply ek_audio_consumer_supplies[] = {
 	REGULATOR_SUPPLY("AVDD", "0-001b"),
@@ -393,6 +404,8 @@ static void __init ek_board_init(void)
 	ek_add_device_gpio_leds();
 	/* Push Buttons */
 	ek_add_device_buttons();
+	/* ADCs */
+	at91_add_device_adc(&ek_adc_data);
 	/* PCK0 provides MCLK to the WM8731 */
 	at91_set_B_periph(AT91_PIN_PC1, 0);
 	/* SSC (for WM8731) */
-- 
1.7.5.4

Re: [PATCH 3/5] ARM: AT91: Add the ADC to the sam9g20ek board

[Jean-Christophe PLAGNIOL-VILLARD]

On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
> This patch adds platform data for the AT91 ADC driver support for
> the AT91SAM9G20-EK board.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Do you have a plan for DT?

Best Regards,
J.

[PATCH 3/5] ARM: AT91: Add the ADC to the sam9g20ek board

[Jean-Christophe PLAGNIOL-VILLARD]

On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
> This patch adds platform data for the AT91 ADC driver support for
> the AT91SAM9G20-EK board.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Do you have a plan for DT?

Best Regards,
J.

Re: [PATCH 3/5] ARM: AT91: Add the ADC to the sam9g20ek board

[Maxime Ripard]

Le 07/04/2012 05:29, Jean-Christophe PLAGNIOL-VILLARD a =E9crit :
> On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
>> This patch adds platform data for the AT91 ADC driver support for
>> the AT91SAM9G20-EK board.
>>
>> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> Do you have a plan for DT?

My plan was to take a look at it while adding support for the X25 and
X35, presumably this week or next week.

I admit I have not looked much into it for now.

Maxime
--=20
Maxime Ripard, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH 3/5] ARM: AT91: Add the ADC to the sam9g20ek board

[Maxime Ripard]

Le 07/04/2012 05:29, Jean-Christophe PLAGNIOL-VILLARD a ?crit :
> On 18:01 Thu 05 Apr     , Maxime Ripard wrote:
>> This patch adds platform data for the AT91 ADC driver support for
>> the AT91SAM9G20-EK board.
>>
>> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> Do you have a plan for DT?

My plan was to take a look at it while adding support for the X25 and
X35, presumably this week or next week.

I admit I have not looked much into it for now.

Maxime
-- 
Maxime Ripard, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH 4/5] IIO: AT91: ADC: Add support for the AT91SAM9M10G45-EK board

[Maxime Ripard]

This patch adds the necessary logic and the required platform_data to
support the ADC present in the AT91SAM9M10G45-EK board from Atmel. It
only supports software triggers for now.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 arch/arm/mach-at91/at91sam9g45_devices.c |   61 ++++++++++++++++++++++++++++++
 arch/arm/mach-at91/board-sam9m10g45ek.c  |   11 +++++
 drivers/staging/iio/adc/at91_adc.c       |   12 ++++++
 3 files changed, 84 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 698479f..7827139 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -19,6 +19,8 @@
 #include <linux/i2c-gpio.h>
 #include <linux/atmel-mci.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <linux/fb.h>
 #include <video/atmel_lcdc.h>
 
@@ -1202,6 +1204,65 @@ void __init at91_add_device_tsadcc(struct at91_tsadcc_data *data) {}
 
 
 /* --------------------------------------------------------------------
+ *  ADC
+ * -------------------------------------------------------------------- */
+
+#if defined(CONFIG_AT91_ADC) || defined(CONFIG_AT91_ADC_MODULE)
+static struct at91_adc_data adc_data;
+
+static struct resource adc_resources[] = {
+	[0] = {
+		.start	= AT91SAM9G45_BASE_TSC,
+		.end	= AT91SAM9G45_BASE_TSC + SZ_16K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= AT91SAM9G45_ID_TSC,
+		.end	= AT91SAM9G45_ID_TSC,
+		.flags	= IORESOURCE_IRQ,
+	}
+};
+
+static struct platform_device at91_adc_device = {
+	.name		= "at91_adc",
+	.id		= -1,
+	.dev		= {
+				.platform_data	= &adc_data,
+	},
+	.resource	= adc_resources,
+	.num_resources	= ARRAY_SIZE(adc_resources),
+};
+
+void __init at91_add_device_adc(struct at91_adc_data *data)
+{
+	if (!data)
+		return;
+
+	if (test_bit(0, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD20, 0);
+	if (test_bit(1, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD21, 0);
+	if (test_bit(2, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD22, 0);
+	if (test_bit(3, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD23, 0);
+	if (test_bit(4, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD24, 0);
+	if (test_bit(5, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD25, 0);
+	if (test_bit(6, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD26, 0);
+	if (test_bit(7, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD27, 0);
+
+	adc_data = *data;
+	platform_device_register(&at91_adc_device);
+}
+#else
+void __init at91_add_device_adc(struct at91_adc_data *data) {}
+#endif
+
+/* --------------------------------------------------------------------
  *  RTT
  * -------------------------------------------------------------------- */
 
diff --git a/arch/arm/mach-at91/board-sam9m10g45ek.c b/arch/arm/mach-at91/board-sam9m10g45ek.c
index e1bea73..dca46c8 100644
--- a/arch/arm/mach-at91/board-sam9m10g45ek.c
+++ b/arch/arm/mach-at91/board-sam9m10g45ek.c
@@ -27,6 +27,8 @@
 #include <linux/atmel-mci.h>
 #include <linux/delay.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/hardware.h>
 #include <video/atmel_lcdc.h>
 #include <media/soc_camera.h>
@@ -314,6 +316,13 @@ static struct at91_tsadcc_data ek_tsadcc_data = {
 	.ts_sample_hold_time	= 0x0a,
 };
 
+/*
+ * ADCs
+ */
+static struct at91_adc_data ek_adc_data = {
+	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5) | BIT(6) | BIT(7),
+	.vref = 3300,
+};
 
 /*
  * GPIO Buttons
@@ -479,6 +488,8 @@ static void __init ek_board_init(void)
 	at91_add_device_lcdc(&ek_lcdc_data);
 	/* Touch Screen */
 	at91_add_device_tsadcc(&ek_tsadcc_data);
+	/* ADC */
+	at91_add_device_adc(&ek_adc_data);
 	/* Push Buttons */
 	ek_add_device_buttons();
 	/* AC97 */
diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
index c76516a..04bac43 100644
--- a/drivers/staging/iio/adc/at91_adc.c
+++ b/drivers/staging/iio/adc/at91_adc.c
@@ -56,6 +56,13 @@ struct at91_adc_state {
 	wait_queue_head_t	wq_data_avail;
 };
 
+static struct at91_adc_desc at91_adc_desc_sam9g45 = {
+	.clock = 13200000,
+	.clock_name = "tsc_clk",
+	.num_channels = 8,
+	.startup_time = 40,
+};
+
 static struct at91_adc_desc at91_adc_desc_sam9g20 = {
 	.clock = 5000000,
 	.clock_name = "adc_clk",
@@ -70,6 +77,11 @@ static int at91_adc_select_soc(struct at91_adc_state *st)
 		return 0;
 	}
 
+	if (cpu_is_at91sam9g45()) {
+		st->desc = &at91_adc_desc_sam9g45;
+		return 0;
+	}
+
 	return -ENODEV;
 }
 
-- 
1.7.5.4

[PATCH 4/5] IIO: AT91: ADC: Add support for the AT91SAM9M10G45-EK board

[Maxime Ripard]

This patch adds the necessary logic and the required platform_data to
support the ADC present in the AT91SAM9M10G45-EK board from Atmel. It
only supports software triggers for now.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 arch/arm/mach-at91/at91sam9g45_devices.c |   61 ++++++++++++++++++++++++++++++
 arch/arm/mach-at91/board-sam9m10g45ek.c  |   11 +++++
 drivers/staging/iio/adc/at91_adc.c       |   12 ++++++
 3 files changed, 84 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 698479f..7827139 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -19,6 +19,8 @@
 #include <linux/i2c-gpio.h>
 #include <linux/atmel-mci.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <linux/fb.h>
 #include <video/atmel_lcdc.h>
 
@@ -1202,6 +1204,65 @@ void __init at91_add_device_tsadcc(struct at91_tsadcc_data *data) {}
 
 
 /* --------------------------------------------------------------------
+ *  ADC
+ * -------------------------------------------------------------------- */
+
+#if defined(CONFIG_AT91_ADC) || defined(CONFIG_AT91_ADC_MODULE)
+static struct at91_adc_data adc_data;
+
+static struct resource adc_resources[] = {
+	[0] = {
+		.start	= AT91SAM9G45_BASE_TSC,
+		.end	= AT91SAM9G45_BASE_TSC + SZ_16K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= AT91SAM9G45_ID_TSC,
+		.end	= AT91SAM9G45_ID_TSC,
+		.flags	= IORESOURCE_IRQ,
+	}
+};
+
+static struct platform_device at91_adc_device = {
+	.name		= "at91_adc",
+	.id		= -1,
+	.dev		= {
+				.platform_data	= &adc_data,
+	},
+	.resource	= adc_resources,
+	.num_resources	= ARRAY_SIZE(adc_resources),
+};
+
+void __init at91_add_device_adc(struct at91_adc_data *data)
+{
+	if (!data)
+		return;
+
+	if (test_bit(0, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD20, 0);
+	if (test_bit(1, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD21, 0);
+	if (test_bit(2, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD22, 0);
+	if (test_bit(3, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD23, 0);
+	if (test_bit(4, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD24, 0);
+	if (test_bit(5, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD25, 0);
+	if (test_bit(6, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD26, 0);
+	if (test_bit(7, &data->channels_used))
+		at91_set_gpio_input(AT91_PIN_PD27, 0);
+
+	adc_data = *data;
+	platform_device_register(&at91_adc_device);
+}
+#else
+void __init at91_add_device_adc(struct at91_adc_data *data) {}
+#endif
+
+/* --------------------------------------------------------------------
  *  RTT
  * -------------------------------------------------------------------- */
 
diff --git a/arch/arm/mach-at91/board-sam9m10g45ek.c b/arch/arm/mach-at91/board-sam9m10g45ek.c
index e1bea73..dca46c8 100644
--- a/arch/arm/mach-at91/board-sam9m10g45ek.c
+++ b/arch/arm/mach-at91/board-sam9m10g45ek.c
@@ -27,6 +27,8 @@
 #include <linux/atmel-mci.h>
 #include <linux/delay.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/hardware.h>
 #include <video/atmel_lcdc.h>
 #include <media/soc_camera.h>
@@ -314,6 +316,13 @@ static struct at91_tsadcc_data ek_tsadcc_data = {
 	.ts_sample_hold_time	= 0x0a,
 };
 
+/*
+ * ADCs
+ */
+static struct at91_adc_data ek_adc_data = {
+	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5) | BIT(6) | BIT(7),
+	.vref = 3300,
+};
 
 /*
  * GPIO Buttons
@@ -479,6 +488,8 @@ static void __init ek_board_init(void)
 	at91_add_device_lcdc(&ek_lcdc_data);
 	/* Touch Screen */
 	at91_add_device_tsadcc(&ek_tsadcc_data);
+	/* ADC */
+	at91_add_device_adc(&ek_adc_data);
 	/* Push Buttons */
 	ek_add_device_buttons();
 	/* AC97 */
diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
index c76516a..04bac43 100644
--- a/drivers/staging/iio/adc/at91_adc.c
+++ b/drivers/staging/iio/adc/at91_adc.c
@@ -56,6 +56,13 @@ struct at91_adc_state {
 	wait_queue_head_t	wq_data_avail;
 };
 
+static struct at91_adc_desc at91_adc_desc_sam9g45 = {
+	.clock = 13200000,
+	.clock_name = "tsc_clk",
+	.num_channels = 8,
+	.startup_time = 40,
+};
+
 static struct at91_adc_desc at91_adc_desc_sam9g20 = {
 	.clock = 5000000,
 	.clock_name = "adc_clk",
@@ -70,6 +77,11 @@ static int at91_adc_select_soc(struct at91_adc_state *st)
 		return 0;
 	}
 
+	if (cpu_is_at91sam9g45()) {
+		st->desc = &at91_adc_desc_sam9g45;
+		return 0;
+	}
+
 	return -ENODEV;
 }
 
-- 
1.7.5.4

Re: [PATCH 4/5] IIO: AT91: ADC: Add support for the AT91SAM9M10G45-EK board

[Jean-Christophe PLAGNIOL-VILLARD]

> diff --git a/arch/arm/mach-at91/board-sam9m10g45ek.c b/arch/arm/mach-at91/board-sam9m10g45ek.c
> index e1bea73..dca46c8 100644
> --- a/arch/arm/mach-at91/board-sam9m10g45ek.c
> +++ b/arch/arm/mach-at91/board-sam9m10g45ek.c
> @@ -27,6 +27,8 @@
>  #include <linux/atmel-mci.h>
>  #include <linux/delay.h>
>  
> +#include <linux/platform_data/at91_adc.h>
> +
>  #include <mach/hardware.h>
>  #include <video/atmel_lcdc.h>
>  #include <media/soc_camera.h>
> @@ -314,6 +316,13 @@ static struct at91_tsadcc_data ek_tsadcc_data = {
>  	.ts_sample_hold_time	= 0x0a,
>  };
>  
> +/*
> + * ADCs
> + */
> +static struct at91_adc_data ek_adc_data = {
> +	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5) | BIT(6) | BIT(7),
> +	.vref = 3300,
> +};
>  
>  /*
>   * GPIO Buttons
> @@ -479,6 +488,8 @@ static void __init ek_board_init(void)
>  	at91_add_device_lcdc(&ek_lcdc_data);
>  	/* Touch Screen */
>  	at91_add_device_tsadcc(&ek_tsadcc_data);
> +	/* ADC */
> +	at91_add_device_adc(&ek_adc_data);
>  	/* Push Buttons */
>  	ek_add_device_buttons();
>  	/* AC97 */
> diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
> index c76516a..04bac43 100644
> --- a/drivers/staging/iio/adc/at91_adc.c
> +++ b/drivers/staging/iio/adc/at91_adc.c
> @@ -56,6 +56,13 @@ struct at91_adc_state {
>  	wait_queue_head_t	wq_data_avail;
>  };
>  
> +static struct at91_adc_desc at91_adc_desc_sam9g45 = {
> +	.clock = 13200000,
> +	.clock_name = "tsc_clk",
> +	.num_channels = 8,
> +	.startup_time = 40,
> +};
> +
>  static struct at91_adc_desc at91_adc_desc_sam9g20 = {
>  	.clock = 5000000,
>  	.clock_name = "adc_clk",
> @@ -70,6 +77,11 @@ static int at91_adc_select_soc(struct at91_adc_state *st)
>  		return 0;
>  	}
>  
> +	if (cpu_is_at91sam9g45()) {
> +		st->desc = &at91_adc_desc_sam9g45;
> +		return 0;
> +	}
> +
>  	return -ENODEV;
>  }
>  
soc specific

Best Regards,
J.

[PATCH 4/5] IIO: AT91: ADC: Add support for the AT91SAM9M10G45-EK board

[Jean-Christophe PLAGNIOL-VILLARD]

> diff --git a/arch/arm/mach-at91/board-sam9m10g45ek.c b/arch/arm/mach-at91/board-sam9m10g45ek.c
> index e1bea73..dca46c8 100644
> --- a/arch/arm/mach-at91/board-sam9m10g45ek.c
> +++ b/arch/arm/mach-at91/board-sam9m10g45ek.c
> @@ -27,6 +27,8 @@
>  #include <linux/atmel-mci.h>
>  #include <linux/delay.h>
>  
> +#include <linux/platform_data/at91_adc.h>
> +
>  #include <mach/hardware.h>
>  #include <video/atmel_lcdc.h>
>  #include <media/soc_camera.h>
> @@ -314,6 +316,13 @@ static struct at91_tsadcc_data ek_tsadcc_data = {
>  	.ts_sample_hold_time	= 0x0a,
>  };
>  
> +/*
> + * ADCs
> + */
> +static struct at91_adc_data ek_adc_data = {
> +	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5) | BIT(6) | BIT(7),
> +	.vref = 3300,
> +};
>  
>  /*
>   * GPIO Buttons
> @@ -479,6 +488,8 @@ static void __init ek_board_init(void)
>  	at91_add_device_lcdc(&ek_lcdc_data);
>  	/* Touch Screen */
>  	at91_add_device_tsadcc(&ek_tsadcc_data);
> +	/* ADC */
> +	at91_add_device_adc(&ek_adc_data);
>  	/* Push Buttons */
>  	ek_add_device_buttons();
>  	/* AC97 */
> diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
> index c76516a..04bac43 100644
> --- a/drivers/staging/iio/adc/at91_adc.c
> +++ b/drivers/staging/iio/adc/at91_adc.c
> @@ -56,6 +56,13 @@ struct at91_adc_state {
>  	wait_queue_head_t	wq_data_avail;
>  };
>  
> +static struct at91_adc_desc at91_adc_desc_sam9g45 = {
> +	.clock = 13200000,
> +	.clock_name = "tsc_clk",
> +	.num_channels = 8,
> +	.startup_time = 40,
> +};
> +
>  static struct at91_adc_desc at91_adc_desc_sam9g20 = {
>  	.clock = 5000000,
>  	.clock_name = "adc_clk",
> @@ -70,6 +77,11 @@ static int at91_adc_select_soc(struct at91_adc_state *st)
>  		return 0;
>  	}
>  
> +	if (cpu_is_at91sam9g45()) {
> +		st->desc = &at91_adc_desc_sam9g45;
> +		return 0;
> +	}
> +
>  	return -ENODEV;
>  }
>  
soc specific

Best Regards,
J.

[PATCH 5/5] IIO: AT91: Add support for hardware triggers for the ADC

[Maxime Ripard]

This patch adds support for the hardware triggers for both the
AT91SAM9G20-EK and AT91SAM9M10G45-EK evaluation board from Atmel.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 arch/arm/mach-at91/at91sam9260_devices.c |    3 +
 arch/arm/mach-at91/at91sam9g45_devices.c |    3 +
 arch/arm/mach-at91/board-sam9g20ek.c     |    1 +
 arch/arm/mach-at91/board-sam9m10g45ek.c  |    1 +
 drivers/staging/iio/adc/Kconfig          |    3 +
 drivers/staging/iio/adc/at91_adc.c       |  390 +++++++++++++++++++++++++++++-
 include/linux/platform_data/at91_adc.h   |    2 +
 7 files changed, 396 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index 08464fe..66df43a 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -1412,6 +1412,9 @@ void __init at91_add_device_adc(struct at91_adc_data *data)
 	if (test_bit(3, &data->channels_used))
 		at91_set_A_periph(AT91_PIN_PC3, 0);
 
+	if (data->use_external)
+		at91_set_A_periph(AT91_PIN_PA22, 0);
+
 	adc_data = *data;
 	platform_device_register(&at91_adc_device);
 }
diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 7827139..13ac3932 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1255,6 +1255,9 @@ void __init at91_add_device_adc(struct at91_adc_data *data)
 	if (test_bit(7, &data->channels_used))
 		at91_set_gpio_input(AT91_PIN_PD27, 0);
 
+	if (data->use_external)
+		at91_set_A_periph(AT91_PIN_PD28, 0);
+
 	adc_data = *data;
 	platform_device_register(&at91_adc_device);
 }
diff --git a/arch/arm/mach-at91/board-sam9g20ek.c b/arch/arm/mach-at91/board-sam9g20ek.c
index 2ce4e26..3bb6e4d 100644
--- a/arch/arm/mach-at91/board-sam9g20ek.c
+++ b/arch/arm/mach-at91/board-sam9g20ek.c
@@ -326,6 +326,7 @@ static void __init ek_add_device_buttons(void) {}
 
 static struct at91_adc_data ek_adc_data = {
 	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3),
+	.use_external = true,
 	.vref = 3300,
 };
 
diff --git a/arch/arm/mach-at91/board-sam9m10g45ek.c b/arch/arm/mach-at91/board-sam9m10g45ek.c
index dca46c8..9a89afc 100644
--- a/arch/arm/mach-at91/board-sam9m10g45ek.c
+++ b/arch/arm/mach-at91/board-sam9m10g45ek.c
@@ -321,6 +321,7 @@ static struct at91_tsadcc_data ek_tsadcc_data = {
  */
 static struct at91_adc_data ek_adc_data = {
 	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5) | BIT(6) | BIT(7),
+	.use_external = true,
 	.vref = 3300,
 };
 
diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index 1494838..9ee7ed9 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -172,6 +172,9 @@ config AD7280
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on SYSFS && ARCH_AT91
+	select IIO_BUFFER
+	select IIO_SW_RING
+	select IIO_TRIGGER
 	help
 	  Say yes here to build support for Atmel AT91 ADC.
 
diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
index 04bac43..57e2161 100644
--- a/drivers/staging/iio/adc/at91_adc.c
+++ b/drivers/staging/iio/adc/at91_adc.c
@@ -23,9 +23,33 @@
 #include "../iio.h"
 #include <linux/platform_data/at91_adc.h>
 
+#include "../buffer.h"
+#include "../ring_sw.h"
+#include "../trigger.h"
+#include "../trigger_consumer.h"
+
 #include <mach/at91_adc.h>
 #include <mach/cpu.h>
 
+#define AT91_TSADCC_TRGR		(0x08)
+#define AT91_TSADCC_TRGMOD_EXT_RISING	(1 << 0)
+#define AT91_TSADCC_TRGMOD_EXT_FALLING	(1 << 1)
+#define AT91_TSADCC_TRGMOD_EXT_ANY	(AT91_TSADCC_TRGMOD_EXT_RISING | AT91_TSADCC_TRGMOD_EXT_FALLING)
+#define AT91_TSADCC_TRGMOD_CONTINUOUS	(3 << 1)
+
+/**
+ * struct at91_adc_trigger - description of triggers
+ * @name:		name of the trigger advertised to the user
+ * @value:		value to set in the ADC's mode register to enable
+			the trigger
+ * @is_external:	is the trigger relies on an external pin ?
+ */
+struct at91_adc_trigger {
+	char	*name;
+	u8	value;
+	bool	is_external;
+};
+
 /**
  * struct at91_adc_desc - description of the ADC on the board
  * @clock:		ADC clock as specified by the datasheet, in Hz.
@@ -35,32 +59,93 @@
 			board, see the channels_used bitmask in the platform
 			data)
  * @startup_time:	startup time of the ADC in microseconds
+ * @triggers:		array of the triggers available on the board
+ * @trigger_register:	index of the register managing the hardware triggers
  */
 struct at91_adc_desc {
 	u32			clock;
 	char			*clock_name;
 	u8			num_channels;
 	u8			startup_time;
+	struct at91_adc_trigger	*triggers;
+	u8			trigger_register;
 };
 
 struct at91_adc_state {
+	u16			*buffer;
 	unsigned long		channels_mask;
 	struct clk		*clk;
 	bool			done;
 	struct at91_adc_desc	*desc;
 	int			irq;
+	bool			irq_enabled;
 	u16			last_value;
 	struct mutex		lock;
 	void __iomem		*reg_base;
+	struct iio_trigger	**trig;
 	u32			vref_mv;
 	wait_queue_head_t	wq_data_avail;
 };
 
+static struct at91_adc_trigger at91_adc_trigger_sam9g45[] = {
+	[0] = {
+		.name = "external-rising",
+		.value = AT91_TSADCC_TRGMOD_EXT_RISING,
+		.is_external = true,
+	},
+	[1] = {
+		.name = "external-falling",
+		.value = AT91_TSADCC_TRGMOD_EXT_FALLING,
+		.is_external = true,
+	},
+	[2] = {
+		.name = "external-any",
+		.value = AT91_TSADCC_TRGMOD_EXT_ANY,
+		.is_external = true,
+	},
+	[3] = {
+		.name = "continuous",
+		.value = AT91_TSADCC_TRGMOD_CONTINUOUS,
+		.is_external = false,
+	},
+	[4] = {
+		.name = NULL,
+	},
+};
+
 static struct at91_adc_desc at91_adc_desc_sam9g45 = {
 	.clock = 13200000,
 	.clock_name = "tsc_clk",
 	.num_channels = 8,
 	.startup_time = 40,
+	.triggers = at91_adc_trigger_sam9g45,
+	.trigger_register = AT91_TSADCC_TRGR,
+};
+
+static struct at91_adc_trigger at91_adc_trigger_sam9g20[] = {
+	[0] = {
+		.name = "timer-counter-0",
+		.value = AT91_ADC_TRGSEL_TC0 | AT91_ADC_TRGEN,
+		.is_external = false,
+	},
+	[1] = {
+		.name = "timer-counter-1",
+		.value = AT91_ADC_TRGSEL_TC1 | AT91_ADC_TRGEN,
+		.is_external = false,
+	},
+	[2] = {
+		.name = "timer-counter-2",
+		.value = AT91_ADC_TRGSEL_TC2 | AT91_ADC_TRGEN,
+		.is_external = false,
+	},
+	[3] = {
+		.name = "external",
+		.value = AT91_ADC_TRGSEL_EXTERNAL | AT91_ADC_TRGEN,
+		.is_external = true,
+	},
+	[4] = {
+		.name = NULL,
+	},
 };
 
 static struct at91_adc_desc at91_adc_desc_sam9g20 = {
@@ -68,6 +153,8 @@ static struct at91_adc_desc at91_adc_desc_sam9g20 = {
 	.clock_name = "adc_clk",
 	.num_channels = 4,
 	.startup_time = 10,
+	.triggers = at91_adc_trigger_sam9g20,
+	.trigger_register = AT91_ADC_MR,
 };
 
 static int at91_adc_select_soc(struct at91_adc_state *st)
@@ -98,6 +185,48 @@ static inline void at91_adc_reg_write(struct at91_adc_state *st,
 	writel_relaxed(val, st->reg_base + reg);
 }
 
+static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *idev = pf->indio_dev;
+	struct at91_adc_state *st = iio_priv(idev);
+	struct iio_buffer *buffer = idev->buffer;
+	int len = 0;
+
+	if (!bitmap_empty(idev->active_scan_mask, idev->masklength)) {
+		int i, j;
+		for (i = 0, j = 0;
+		     i < bitmap_weight(idev->active_scan_mask,
+				       idev->masklength);
+		     i++) {
+			j = find_next_bit(buffer->scan_mask,
+					  idev->masklength,
+					  j);
+			st->buffer[i] = at91_adc_reg_read(st, AT91_ADC_CHR(j));
+			j++;
+			len += 2;
+		}
+	}
+
+	if (buffer->scan_timestamp) {
+		s64 *timestamp = (s64 *)((u8 *)st->buffer + ALIGN(len,
+								  sizeof(s64)));
+		*timestamp = pf->timestamp;
+	}
+
+	buffer->access->store_to(buffer, (u8 *)st->buffer, pf->timestamp);
+
+	iio_trigger_notify_done(idev->trig);
+	st->irq_enabled = true;
+
+	/* Needed to ACK the DRDY interruption */
+	at91_adc_reg_read(st, AT91_ADC_LCDR);
+
+	enable_irq(st->irq);
+
+	return IRQ_HANDLED;
+}
+
 static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
 {
 	struct iio_dev *idev = private;
@@ -107,13 +236,16 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
 	if (!(status & AT91_ADC_DRDY))
 		return IRQ_HANDLED;
 
-	if (status & st->channels_mask) {
-		st->done = true;
+	if (iio_buffer_enabled(idev)) {
+		disable_irq_nosync(irq);
+		st->irq_enabled = false;
+		iio_trigger_poll(idev->trig, iio_get_time_ns());
+	} else {
 		st->last_value = at91_adc_reg_read(st, AT91_ADC_LCDR);
+		st->done = true;
+		wake_up_interruptible(&st->wq_data_avail);
 	}
 
-	wake_up_interruptible(&st->wq_data_avail);
-
 	return IRQ_HANDLED;
 }
 
@@ -125,8 +257,9 @@ static int at91_adc_channel_init(struct iio_dev *idev,
 	int bit, idx = 0;
 
 	idev->num_channels = bitmap_weight(&pdata->channels_used,
-					   st->desc->num_channels);
-	chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
+					   st->desc->num_channels) + 1;
+	chan_array = kcalloc(idev->num_channels + 1,
+			     sizeof(struct iio_chan_spec),
 			     GFP_KERNEL);
 
 	if (chan_array == NULL)
@@ -137,6 +270,7 @@ static int at91_adc_channel_init(struct iio_dev *idev,
 		chan->type = IIO_VOLTAGE;
 		chan->indexed = 1;
 		chan->channel = bit;
+		chan->scan_index = idx;
 		chan->scan_type.sign = 'u';
 		chan->scan_type.realbits = 10;
 		chan->scan_type.storagebits = 16;
@@ -144,6 +278,13 @@ static int at91_adc_channel_init(struct iio_dev *idev,
 		idx++;
 	}
 
+	(chan_array + idx)->type = IIO_TIMESTAMP;
+	(chan_array + idx)->channel = -1;
+	(chan_array + idx)->scan_index = idx;
+	(chan_array + idx)->scan_type.sign = 's';
+	(chan_array + idx)->scan_type.realbits = 64;
+	(chan_array + idx)->scan_type.storagebits = 64;
+
 	idev->channels = chan_array;
 	return idev->num_channels;
 }
@@ -153,6 +294,223 @@ static void at91_adc_channel_remove(struct iio_dev *idev)
 	kfree(idev->channels);
 }
 
+static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
+					     struct at91_adc_trigger *triggers,
+					     const char *trigger_name)
+{
+	u8 value = 0;
+	int i;
+
+	for (i = 0; (triggers + i) != NULL; i++) {
+		char *name = kasprintf(GFP_KERNEL,
+				"%s-dev%d-%s",
+				idev->name,
+				idev->id,
+				triggers[i].name);
+		if (name == NULL)
+			return -ENOMEM;
+
+		if (strcmp(trigger_name, name) == 0) {
+			value = triggers[i].value;
+			kfree(name);
+			break;
+		}
+
+		kfree(name);
+	}
+
+	return value;
+}
+
+static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *idev = trig->private_data;
+	struct at91_adc_state *st = iio_priv(idev);
+	struct iio_buffer *buffer = idev->buffer;
+	u32 status = at91_adc_reg_read(st, st->desc->trigger_register);
+	u8 value;
+	u8 bit;
+
+	value = at91_adc_get_trigger_value_by_name(idev,
+						   st->desc->triggers,
+						   idev->trig->name);
+	if (value == 0)
+		return -EINVAL;
+
+	if (state) {
+		size_t datasize = buffer->access->get_bytes_per_datum(buffer);
+
+		st->buffer = kmalloc(datasize, GFP_KERNEL);
+		if (st->buffer == NULL)
+			return -ENOMEM;
+
+		at91_adc_reg_write(st,
+				   st->desc->trigger_register,
+				   status | value);
+
+		for_each_set_bit(bit, buffer->scan_mask,
+				 st->desc->num_channels) {
+			struct iio_chan_spec const *chan = idev->channels + bit;
+			at91_adc_reg_write(st, AT91_ADC_CHER,
+					   AT91_ADC_CH(chan->channel));
+		}
+
+		at91_adc_reg_write(st, AT91_ADC_IER, AT91_ADC_DRDY);
+
+	} else {
+		at91_adc_reg_write(st, AT91_ADC_IDR, AT91_ADC_DRDY);
+
+		at91_adc_reg_write(st, st->desc->trigger_register,
+				   status & ~value);
+
+		for_each_set_bit(bit, buffer->scan_mask,
+				 st->desc->num_channels) {
+			struct iio_chan_spec const *chan = idev->channels + bit;
+			at91_adc_reg_write(st, AT91_ADC_CHDR,
+					   AT91_ADC_CH(chan->channel));
+		}
+		kfree(st->buffer);
+	}
+
+	return 0;
+}
+
+static const struct iio_trigger_ops at91_adc_trigger_ops = {
+	.owner = THIS_MODULE,
+	.set_trigger_state = &at91_adc_configure_trigger,
+};
+
+static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
+						     struct at91_adc_trigger *trigger)
+{
+	struct iio_trigger *trig = iio_allocate_trigger("%s-dev%d-%s",
+							idev->name,
+							idev->id,
+							trigger->name);
+	int ret;
+
+	if (trig == NULL)
+		return NULL;
+
+	trig->dev.parent = idev->dev.parent;
+	trig->private_data = idev;
+	trig->ops = &at91_adc_trigger_ops;
+
+	ret = iio_trigger_register(trig);
+	if (ret < 0)
+		return NULL;
+
+	return trig;
+}
+
+static int at91_adc_trigger_init(struct iio_dev *idev,
+				 struct at91_adc_data *pdata)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	int i, ret;
+
+	st->trig = kcalloc(sizeof(st->desc->triggers),
+			   sizeof(st->trig),
+			   GFP_KERNEL);
+
+	if (st->trig == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	for (i = 0; st->desc->triggers[i].name != NULL; i++) {
+		if (st->desc->triggers[i].is_external && !(pdata->use_external))
+			continue;
+
+		st->trig[i] = at91_adc_allocate_trigger(idev,
+							st->desc->triggers + i);
+		if (st->trig[i] == NULL) {
+			dev_err(&idev->dev,
+				"Could not allocate trigger %d\n", i);
+			ret = -ENOMEM;
+			goto error_trigger;
+		}
+	}
+
+	return 0;
+
+error_trigger:
+	for (i--; i >= 0; i--) {
+		iio_trigger_unregister(st->trig[i]);
+		iio_free_trigger(st->trig[i]);
+	}
+	kfree(st->trig);
+error_ret:
+	return ret;
+}
+
+static void at91_adc_trigger_remove(struct iio_dev *idev)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	int i;
+
+	for (i = 0; st->desc->triggers[i].name != NULL; i++) {
+		iio_trigger_unregister(st->trig[i]);
+		iio_free_trigger(st->trig[i]);
+	}
+
+	kfree(st->trig);
+}
+
+static const struct iio_buffer_setup_ops at91_adc_buffer_ops = {
+	.preenable = &iio_sw_buffer_preenable,
+	.postenable = &iio_triggered_buffer_postenable,
+	.predisable = &iio_triggered_buffer_predisable,
+};
+
+static int at91_adc_buffer_init(struct iio_dev *idev)
+{
+	int ret;
+
+	idev->buffer = iio_sw_rb_allocate(idev);
+	if (!idev->buffer) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	idev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
+					    &at91_adc_trigger_handler,
+					    IRQF_ONESHOT,
+					    idev,
+					    "%s-consumer%d",
+					    idev->name,
+					    idev->id);
+	if (idev->pollfunc == NULL) {
+		ret = -ENOMEM;
+		goto error_pollfunc;
+	}
+
+	idev->setup_ops = &at91_adc_buffer_ops;
+	idev->modes |= INDIO_BUFFER_TRIGGERED;
+
+	ret = iio_buffer_register(idev,
+				  idev->channels,
+				  idev->num_channels);
+	if (ret)
+		goto error_register;
+
+	return 0;
+
+error_register:
+	iio_dealloc_pollfunc(idev->pollfunc);
+error_pollfunc:
+	iio_sw_rb_free(idev->buffer);
+error_ret:
+	return ret;
+}
+
+static void at91_adc_buffer_remove(struct iio_dev *idev)
+{
+	iio_buffer_unregister(idev);
+	iio_dealloc_pollfunc(idev->pollfunc);
+	iio_sw_rb_free(idev->buffer);
+}
+
 static int at91_adc_read_raw(struct iio_dev *idev,
 			     struct iio_chan_spec const *chan,
 			     int *val, int *val2, long mask)
@@ -336,14 +694,30 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
 	st->vref_mv = pdata->vref;
 	st->channels_mask = pdata->channels_used;
 
+	ret = at91_adc_buffer_init(idev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
+		goto error_free_channels;
+	}
+
+	ret = at91_adc_trigger_init(idev, pdata);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
+		goto error_unregister_buffer;
+	}
+
 	ret = iio_device_register(idev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Couldn't register the device.\n");
-		goto error_free_channels;
+		goto error_remove_triggers;
 	}
 
 	return 0;
 
+error_remove_triggers:
+	at91_adc_trigger_remove(idev);
+error_unregister_buffer:
+	at91_adc_buffer_remove(idev);
 error_free_channels:
 	at91_adc_channel_remove(idev);
 error_free_clk:
@@ -368,6 +742,8 @@ static int __devexit at91_adc_remove(struct platform_device *pdev)
 	struct at91_adc_state *st = iio_priv(idev);
 
 	iio_device_unregister(idev);
+	at91_adc_trigger_remove(idev);
+	at91_adc_buffer_remove(idev);
 	at91_adc_channel_remove(idev);
 	clk_disable(st->clk);
 	clk_put(st->clk);
diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
index 1f71510..5e063b3 100644
--- a/include/linux/platform_data/at91_adc.h
+++ b/include/linux/platform_data/at91_adc.h
@@ -11,10 +11,12 @@
 /**
  * struct at91_adc_data - platform data for ADC driver
  * @channels_used:	channels in use on the board as a bitmask
+ * @use_external:	does the board has external triggers availables
  * @vref:		Reference voltage for the ADC in millivolts
  */
 struct at91_adc_data {
 	unsigned long	channels_used;
+	bool		use_external;
 	u16		vref;
 };
 
-- 
1.7.5.4

[PATCH 5/5] IIO: AT91: Add support for hardware triggers for the ADC

[Maxime Ripard]

This patch adds support for the hardware triggers for both the
AT91SAM9G20-EK and AT91SAM9M10G45-EK evaluation board from Atmel.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 arch/arm/mach-at91/at91sam9260_devices.c |    3 +
 arch/arm/mach-at91/at91sam9g45_devices.c |    3 +
 arch/arm/mach-at91/board-sam9g20ek.c     |    1 +
 arch/arm/mach-at91/board-sam9m10g45ek.c  |    1 +
 drivers/staging/iio/adc/Kconfig          |    3 +
 drivers/staging/iio/adc/at91_adc.c       |  390 +++++++++++++++++++++++++++++-
 include/linux/platform_data/at91_adc.h   |    2 +
 7 files changed, 396 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index 08464fe..66df43a 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -1412,6 +1412,9 @@ void __init at91_add_device_adc(struct at91_adc_data *data)
 	if (test_bit(3, &data->channels_used))
 		at91_set_A_periph(AT91_PIN_PC3, 0);
 
+	if (data->use_external)
+		at91_set_A_periph(AT91_PIN_PA22, 0);
+
 	adc_data = *data;
 	platform_device_register(&at91_adc_device);
 }
diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 7827139..13ac3932 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -1255,6 +1255,9 @@ void __init at91_add_device_adc(struct at91_adc_data *data)
 	if (test_bit(7, &data->channels_used))
 		at91_set_gpio_input(AT91_PIN_PD27, 0);
 
+	if (data->use_external)
+		at91_set_A_periph(AT91_PIN_PD28, 0);
+
 	adc_data = *data;
 	platform_device_register(&at91_adc_device);
 }
diff --git a/arch/arm/mach-at91/board-sam9g20ek.c b/arch/arm/mach-at91/board-sam9g20ek.c
index 2ce4e26..3bb6e4d 100644
--- a/arch/arm/mach-at91/board-sam9g20ek.c
+++ b/arch/arm/mach-at91/board-sam9g20ek.c
@@ -326,6 +326,7 @@ static void __init ek_add_device_buttons(void) {}
 
 static struct at91_adc_data ek_adc_data = {
 	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3),
+	.use_external = true,
 	.vref = 3300,
 };
 
diff --git a/arch/arm/mach-at91/board-sam9m10g45ek.c b/arch/arm/mach-at91/board-sam9m10g45ek.c
index dca46c8..9a89afc 100644
--- a/arch/arm/mach-at91/board-sam9m10g45ek.c
+++ b/arch/arm/mach-at91/board-sam9m10g45ek.c
@@ -321,6 +321,7 @@ static struct at91_tsadcc_data ek_tsadcc_data = {
  */
 static struct at91_adc_data ek_adc_data = {
 	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) | BIT(5) | BIT(6) | BIT(7),
+	.use_external = true,
 	.vref = 3300,
 };
 
diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index 1494838..9ee7ed9 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -172,6 +172,9 @@ config AD7280
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on SYSFS && ARCH_AT91
+	select IIO_BUFFER
+	select IIO_SW_RING
+	select IIO_TRIGGER
 	help
 	  Say yes here to build support for Atmel AT91 ADC.
 
diff --git a/drivers/staging/iio/adc/at91_adc.c b/drivers/staging/iio/adc/at91_adc.c
index 04bac43..57e2161 100644
--- a/drivers/staging/iio/adc/at91_adc.c
+++ b/drivers/staging/iio/adc/at91_adc.c
@@ -23,9 +23,33 @@
 #include "../iio.h"
 #include <linux/platform_data/at91_adc.h>
 
+#include "../buffer.h"
+#include "../ring_sw.h"
+#include "../trigger.h"
+#include "../trigger_consumer.h"
+
 #include <mach/at91_adc.h>
 #include <mach/cpu.h>
 
+#define AT91_TSADCC_TRGR		(0x08)
+#define AT91_TSADCC_TRGMOD_EXT_RISING	(1 << 0)
+#define AT91_TSADCC_TRGMOD_EXT_FALLING	(1 << 1)
+#define AT91_TSADCC_TRGMOD_EXT_ANY	(AT91_TSADCC_TRGMOD_EXT_RISING | AT91_TSADCC_TRGMOD_EXT_FALLING)
+#define AT91_TSADCC_TRGMOD_CONTINUOUS	(3 << 1)
+
+/**
+ * struct at91_adc_trigger - description of triggers
+ * @name:		name of the trigger advertised to the user
+ * @value:		value to set in the ADC's mode register to enable
+			the trigger
+ * @is_external:	is the trigger relies on an external pin ?
+ */
+struct at91_adc_trigger {
+	char	*name;
+	u8	value;
+	bool	is_external;
+};
+
 /**
  * struct at91_adc_desc - description of the ADC on the board
  * @clock:		ADC clock as specified by the datasheet, in Hz.
@@ -35,32 +59,93 @@
 			board, see the channels_used bitmask in the platform
 			data)
  * @startup_time:	startup time of the ADC in microseconds
+ * @triggers:		array of the triggers available on the board
+ * @trigger_register:	index of the register managing the hardware triggers
  */
 struct at91_adc_desc {
 	u32			clock;
 	char			*clock_name;
 	u8			num_channels;
 	u8			startup_time;
+	struct at91_adc_trigger	*triggers;
+	u8			trigger_register;
 };
 
 struct at91_adc_state {
+	u16			*buffer;
 	unsigned long		channels_mask;
 	struct clk		*clk;
 	bool			done;
 	struct at91_adc_desc	*desc;
 	int			irq;
+	bool			irq_enabled;
 	u16			last_value;
 	struct mutex		lock;
 	void __iomem		*reg_base;
+	struct iio_trigger	**trig;
 	u32			vref_mv;
 	wait_queue_head_t	wq_data_avail;
 };
 
+static struct at91_adc_trigger at91_adc_trigger_sam9g45[] = {
+	[0] = {
+		.name = "external-rising",
+		.value = AT91_TSADCC_TRGMOD_EXT_RISING,
+		.is_external = true,
+	},
+	[1] = {
+		.name = "external-falling",
+		.value = AT91_TSADCC_TRGMOD_EXT_FALLING,
+		.is_external = true,
+	},
+	[2] = {
+		.name = "external-any",
+		.value = AT91_TSADCC_TRGMOD_EXT_ANY,
+		.is_external = true,
+	},
+	[3] = {
+		.name = "continuous",
+		.value = AT91_TSADCC_TRGMOD_CONTINUOUS,
+		.is_external = false,
+	},
+	[4] = {
+		.name = NULL,
+	},
+};
+
 static struct at91_adc_desc at91_adc_desc_sam9g45 = {
 	.clock = 13200000,
 	.clock_name = "tsc_clk",
 	.num_channels = 8,
 	.startup_time = 40,
+	.triggers = at91_adc_trigger_sam9g45,
+	.trigger_register = AT91_TSADCC_TRGR,
+};
+
+static struct at91_adc_trigger at91_adc_trigger_sam9g20[] = {
+	[0] = {
+		.name = "timer-counter-0",
+		.value = AT91_ADC_TRGSEL_TC0 | AT91_ADC_TRGEN,
+		.is_external = false,
+	},
+	[1] = {
+		.name = "timer-counter-1",
+		.value = AT91_ADC_TRGSEL_TC1 | AT91_ADC_TRGEN,
+		.is_external = false,
+	},
+	[2] = {
+		.name = "timer-counter-2",
+		.value = AT91_ADC_TRGSEL_TC2 | AT91_ADC_TRGEN,
+		.is_external = false,
+	},
+	[3] = {
+		.name = "external",
+		.value = AT91_ADC_TRGSEL_EXTERNAL | AT91_ADC_TRGEN,
+		.is_external = true,
+	},
+	[4] = {
+		.name = NULL,
+	},
 };
 
 static struct at91_adc_desc at91_adc_desc_sam9g20 = {
@@ -68,6 +153,8 @@ static struct at91_adc_desc at91_adc_desc_sam9g20 = {
 	.clock_name = "adc_clk",
 	.num_channels = 4,
 	.startup_time = 10,
+	.triggers = at91_adc_trigger_sam9g20,
+	.trigger_register = AT91_ADC_MR,
 };
 
 static int at91_adc_select_soc(struct at91_adc_state *st)
@@ -98,6 +185,48 @@ static inline void at91_adc_reg_write(struct at91_adc_state *st,
 	writel_relaxed(val, st->reg_base + reg);
 }
 
+static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *idev = pf->indio_dev;
+	struct at91_adc_state *st = iio_priv(idev);
+	struct iio_buffer *buffer = idev->buffer;
+	int len = 0;
+
+	if (!bitmap_empty(idev->active_scan_mask, idev->masklength)) {
+		int i, j;
+		for (i = 0, j = 0;
+		     i < bitmap_weight(idev->active_scan_mask,
+				       idev->masklength);
+		     i++) {
+			j = find_next_bit(buffer->scan_mask,
+					  idev->masklength,
+					  j);
+			st->buffer[i] = at91_adc_reg_read(st, AT91_ADC_CHR(j));
+			j++;
+			len += 2;
+		}
+	}
+
+	if (buffer->scan_timestamp) {
+		s64 *timestamp = (s64 *)((u8 *)st->buffer + ALIGN(len,
+								  sizeof(s64)));
+		*timestamp = pf->timestamp;
+	}
+
+	buffer->access->store_to(buffer, (u8 *)st->buffer, pf->timestamp);
+
+	iio_trigger_notify_done(idev->trig);
+	st->irq_enabled = true;
+
+	/* Needed to ACK the DRDY interruption */
+	at91_adc_reg_read(st, AT91_ADC_LCDR);
+
+	enable_irq(st->irq);
+
+	return IRQ_HANDLED;
+}
+
 static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
 {
 	struct iio_dev *idev = private;
@@ -107,13 +236,16 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
 	if (!(status & AT91_ADC_DRDY))
 		return IRQ_HANDLED;
 
-	if (status & st->channels_mask) {
-		st->done = true;
+	if (iio_buffer_enabled(idev)) {
+		disable_irq_nosync(irq);
+		st->irq_enabled = false;
+		iio_trigger_poll(idev->trig, iio_get_time_ns());
+	} else {
 		st->last_value = at91_adc_reg_read(st, AT91_ADC_LCDR);
+		st->done = true;
+		wake_up_interruptible(&st->wq_data_avail);
 	}
 
-	wake_up_interruptible(&st->wq_data_avail);
-
 	return IRQ_HANDLED;
 }
 
@@ -125,8 +257,9 @@ static int at91_adc_channel_init(struct iio_dev *idev,
 	int bit, idx = 0;
 
 	idev->num_channels = bitmap_weight(&pdata->channels_used,
-					   st->desc->num_channels);
-	chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
+					   st->desc->num_channels) + 1;
+	chan_array = kcalloc(idev->num_channels + 1,
+			     sizeof(struct iio_chan_spec),
 			     GFP_KERNEL);
 
 	if (chan_array == NULL)
@@ -137,6 +270,7 @@ static int at91_adc_channel_init(struct iio_dev *idev,
 		chan->type = IIO_VOLTAGE;
 		chan->indexed = 1;
 		chan->channel = bit;
+		chan->scan_index = idx;
 		chan->scan_type.sign = 'u';
 		chan->scan_type.realbits = 10;
 		chan->scan_type.storagebits = 16;
@@ -144,6 +278,13 @@ static int at91_adc_channel_init(struct iio_dev *idev,
 		idx++;
 	}
 
+	(chan_array + idx)->type = IIO_TIMESTAMP;
+	(chan_array + idx)->channel = -1;
+	(chan_array + idx)->scan_index = idx;
+	(chan_array + idx)->scan_type.sign = 's';
+	(chan_array + idx)->scan_type.realbits = 64;
+	(chan_array + idx)->scan_type.storagebits = 64;
+
 	idev->channels = chan_array;
 	return idev->num_channels;
 }
@@ -153,6 +294,223 @@ static void at91_adc_channel_remove(struct iio_dev *idev)
 	kfree(idev->channels);
 }
 
+static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
+					     struct at91_adc_trigger *triggers,
+					     const char *trigger_name)
+{
+	u8 value = 0;
+	int i;
+
+	for (i = 0; (triggers + i) != NULL; i++) {
+		char *name = kasprintf(GFP_KERNEL,
+				"%s-dev%d-%s",
+				idev->name,
+				idev->id,
+				triggers[i].name);
+		if (name == NULL)
+			return -ENOMEM;
+
+		if (strcmp(trigger_name, name) == 0) {
+			value = triggers[i].value;
+			kfree(name);
+			break;
+		}
+
+		kfree(name);
+	}
+
+	return value;
+}
+
+static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *idev = trig->private_data;
+	struct at91_adc_state *st = iio_priv(idev);
+	struct iio_buffer *buffer = idev->buffer;
+	u32 status = at91_adc_reg_read(st, st->desc->trigger_register);
+	u8 value;
+	u8 bit;
+
+	value = at91_adc_get_trigger_value_by_name(idev,
+						   st->desc->triggers,
+						   idev->trig->name);
+	if (value == 0)
+		return -EINVAL;
+
+	if (state) {
+		size_t datasize = buffer->access->get_bytes_per_datum(buffer);
+
+		st->buffer = kmalloc(datasize, GFP_KERNEL);
+		if (st->buffer == NULL)
+			return -ENOMEM;
+
+		at91_adc_reg_write(st,
+				   st->desc->trigger_register,
+				   status | value);
+
+		for_each_set_bit(bit, buffer->scan_mask,
+				 st->desc->num_channels) {
+			struct iio_chan_spec const *chan = idev->channels + bit;
+			at91_adc_reg_write(st, AT91_ADC_CHER,
+					   AT91_ADC_CH(chan->channel));
+		}
+
+		at91_adc_reg_write(st, AT91_ADC_IER, AT91_ADC_DRDY);
+
+	} else {
+		at91_adc_reg_write(st, AT91_ADC_IDR, AT91_ADC_DRDY);
+
+		at91_adc_reg_write(st, st->desc->trigger_register,
+				   status & ~value);
+
+		for_each_set_bit(bit, buffer->scan_mask,
+				 st->desc->num_channels) {
+			struct iio_chan_spec const *chan = idev->channels + bit;
+			at91_adc_reg_write(st, AT91_ADC_CHDR,
+					   AT91_ADC_CH(chan->channel));
+		}
+		kfree(st->buffer);
+	}
+
+	return 0;
+}
+
+static const struct iio_trigger_ops at91_adc_trigger_ops = {
+	.owner = THIS_MODULE,
+	.set_trigger_state = &at91_adc_configure_trigger,
+};
+
+static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
+						     struct at91_adc_trigger *trigger)
+{
+	struct iio_trigger *trig = iio_allocate_trigger("%s-dev%d-%s",
+							idev->name,
+							idev->id,
+							trigger->name);
+	int ret;
+
+	if (trig == NULL)
+		return NULL;
+
+	trig->dev.parent = idev->dev.parent;
+	trig->private_data = idev;
+	trig->ops = &at91_adc_trigger_ops;
+
+	ret = iio_trigger_register(trig);
+	if (ret < 0)
+		return NULL;
+
+	return trig;
+}
+
+static int at91_adc_trigger_init(struct iio_dev *idev,
+				 struct at91_adc_data *pdata)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	int i, ret;
+
+	st->trig = kcalloc(sizeof(st->desc->triggers),
+			   sizeof(st->trig),
+			   GFP_KERNEL);
+
+	if (st->trig == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	for (i = 0; st->desc->triggers[i].name != NULL; i++) {
+		if (st->desc->triggers[i].is_external && !(pdata->use_external))
+			continue;
+
+		st->trig[i] = at91_adc_allocate_trigger(idev,
+							st->desc->triggers + i);
+		if (st->trig[i] == NULL) {
+			dev_err(&idev->dev,
+				"Could not allocate trigger %d\n", i);
+			ret = -ENOMEM;
+			goto error_trigger;
+		}
+	}
+
+	return 0;
+
+error_trigger:
+	for (i--; i >= 0; i--) {
+		iio_trigger_unregister(st->trig[i]);
+		iio_free_trigger(st->trig[i]);
+	}
+	kfree(st->trig);
+error_ret:
+	return ret;
+}
+
+static void at91_adc_trigger_remove(struct iio_dev *idev)
+{
+	struct at91_adc_state *st = iio_priv(idev);
+	int i;
+
+	for (i = 0; st->desc->triggers[i].name != NULL; i++) {
+		iio_trigger_unregister(st->trig[i]);
+		iio_free_trigger(st->trig[i]);
+	}
+
+	kfree(st->trig);
+}
+
+static const struct iio_buffer_setup_ops at91_adc_buffer_ops = {
+	.preenable = &iio_sw_buffer_preenable,
+	.postenable = &iio_triggered_buffer_postenable,
+	.predisable = &iio_triggered_buffer_predisable,
+};
+
+static int at91_adc_buffer_init(struct iio_dev *idev)
+{
+	int ret;
+
+	idev->buffer = iio_sw_rb_allocate(idev);
+	if (!idev->buffer) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	idev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
+					    &at91_adc_trigger_handler,
+					    IRQF_ONESHOT,
+					    idev,
+					    "%s-consumer%d",
+					    idev->name,
+					    idev->id);
+	if (idev->pollfunc == NULL) {
+		ret = -ENOMEM;
+		goto error_pollfunc;
+	}
+
+	idev->setup_ops = &at91_adc_buffer_ops;
+	idev->modes |= INDIO_BUFFER_TRIGGERED;
+
+	ret = iio_buffer_register(idev,
+				  idev->channels,
+				  idev->num_channels);
+	if (ret)
+		goto error_register;
+
+	return 0;
+
+error_register:
+	iio_dealloc_pollfunc(idev->pollfunc);
+error_pollfunc:
+	iio_sw_rb_free(idev->buffer);
+error_ret:
+	return ret;
+}
+
+static void at91_adc_buffer_remove(struct iio_dev *idev)
+{
+	iio_buffer_unregister(idev);
+	iio_dealloc_pollfunc(idev->pollfunc);
+	iio_sw_rb_free(idev->buffer);
+}
+
 static int at91_adc_read_raw(struct iio_dev *idev,
 			     struct iio_chan_spec const *chan,
 			     int *val, int *val2, long mask)
@@ -336,14 +694,30 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
 	st->vref_mv = pdata->vref;
 	st->channels_mask = pdata->channels_used;
 
+	ret = at91_adc_buffer_init(idev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
+		goto error_free_channels;
+	}
+
+	ret = at91_adc_trigger_init(idev, pdata);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
+		goto error_unregister_buffer;
+	}
+
 	ret = iio_device_register(idev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Couldn't register the device.\n");
-		goto error_free_channels;
+		goto error_remove_triggers;
 	}
 
 	return 0;
 
+error_remove_triggers:
+	at91_adc_trigger_remove(idev);
+error_unregister_buffer:
+	at91_adc_buffer_remove(idev);
 error_free_channels:
 	at91_adc_channel_remove(idev);
 error_free_clk:
@@ -368,6 +742,8 @@ static int __devexit at91_adc_remove(struct platform_device *pdev)
 	struct at91_adc_state *st = iio_priv(idev);
 
 	iio_device_unregister(idev);
+	at91_adc_trigger_remove(idev);
+	at91_adc_buffer_remove(idev);
 	at91_adc_channel_remove(idev);
 	clk_disable(st->clk);
 	clk_put(st->clk);
diff --git a/include/linux/platform_data/at91_adc.h b/include/linux/platform_data/at91_adc.h
index 1f71510..5e063b3 100644
--- a/include/linux/platform_data/at91_adc.h
+++ b/include/linux/platform_data/at91_adc.h
@@ -11,10 +11,12 @@
 /**
  * struct at91_adc_data - platform data for ADC driver
  * @channels_used:	channels in use on the board as a bitmask
+ * @use_external:	does the board has external triggers availables
  * @vref:		Reference voltage for the ADC in millivolts
  */
 struct at91_adc_data {
 	unsigned long	channels_used;
+	bool		use_external;
 	u16		vref;
 };
 
-- 
1.7.5.4

Re: [PATCH 5/5] IIO: AT91: Add support for hardware triggers for the ADC

[Jean-Christophe PLAGNIOL-VILLARD]

>  
> +static struct at91_adc_trigger at91_adc_trigger_sam9g45[] = {
> +	[0] = {
> +		.name = "external-rising",
> +		.value = AT91_TSADCC_TRGMOD_EXT_RISING,
> +		.is_external = true,
> +	},
> +	[1] = {
> +		.name = "external-falling",
> +		.value = AT91_TSADCC_TRGMOD_EXT_FALLING,
> +		.is_external = true,
> +	},
> +	[2] = {
> +		.name = "external-any",
> +		.value = AT91_TSADCC_TRGMOD_EXT_ANY,
> +		.is_external = true,
> +	},
> +	[3] = {
> +		.name = "continuous",
> +		.value = AT91_TSADCC_TRGMOD_CONTINUOUS,
> +		.is_external = false,
> +	},
> +	[4] = {
> +		.name = NULL,
> +	},
> +};
> +
>  static struct at91_adc_desc at91_adc_desc_sam9g45 = {
>  	.clock = 13200000,
>  	.clock_name = "tsc_clk",
>  	.num_channels = 8,
>  	.startup_time = 40,
> +	.triggers = at91_adc_trigger_sam9g45,
> +	.trigger_register = AT91_TSADCC_TRGR,
> +};
> +
> +static struct at91_adc_trigger at91_adc_trigger_sam9g20[] = {
> +	[0] = {
> +		.name = "timer-counter-0",
> +		.value = AT91_ADC_TRGSEL_TC0 | AT91_ADC_TRGEN,
> +		.is_external = false,
> +	},
> +	[1] = {
> +		.name = "timer-counter-1",
> +		.value = AT91_ADC_TRGSEL_TC1 | AT91_ADC_TRGEN,
> +		.is_external = false,
> +	},
> +	[2] = {
> +		.name = "timer-counter-2",
> +		.value = AT91_ADC_TRGSEL_TC2 | AT91_ADC_TRGEN,
> +		.is_external = false,
> +	},
> +	[3] = {
> +		.name = "external",
> +		.value = AT91_ADC_TRGSEL_EXTERNAL | AT91_ADC_TRGEN,
> +		.is_external = true,
> +	},
> +	[4] = {
> +		.name = NULL,
> +	},
>  };
>  
>  static struct at91_adc_desc at91_adc_desc_sam9g20 = {
> @@ -68,6 +153,8 @@ static struct at91_adc_desc at91_adc_desc_sam9g20 = {
>  	.clock_name = "adc_clk",
>  	.num_channels = 4,
>  	.startup_time = 10,
> +	.triggers = at91_adc_trigger_sam9g20,
> +	.trigger_register = AT91_ADC_MR,
>  };
same comment as before this soc specific

Best Regards,
J.
>  
> @@ -125,8 +257,9 @@ static int at91_adc_channel_init(struct iio_dev *idev,
>  	int bit, idx = 0;
>  
>  	idev->num_channels = bitmap_weight(&pdata->channels_used,
> -					   st->desc->num_channels);
> -	chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
> +					   st->desc->num_channels) + 1;
> +	chan_array = kcalloc(idev->num_channels + 1,
> +			     sizeof(struct iio_chan_spec),
>  			     GFP_KERNEL);
devm_kzalloc
>  
>  	if (chan_array == NULL)
> @@ -137,6 +270,7 @@ static int at91_adc_channel_init(struct iio_dev *idev,
>  		chan->type = IIO_VOLTAGE;
>  		chan->indexed = 1;
>  		chan->channel = bit;
> +		chan->scan_index = idx;
>  		chan->scan_type.sign = 'u';
>  		chan->scan_type.realbits = 10;
>  		chan->scan_type.storagebits = 16;
> @@ -144,6 +278,13 @@ static int at91_adc_channel_init(struct iio_dev *idev,
>  		idx++;
>  	}
Best Regards,
J.

[PATCH 5/5] IIO: AT91: Add support for hardware triggers for the ADC

[Jean-Christophe PLAGNIOL-VILLARD]

>  
> +static struct at91_adc_trigger at91_adc_trigger_sam9g45[] = {
> +	[0] = {
> +		.name = "external-rising",
> +		.value = AT91_TSADCC_TRGMOD_EXT_RISING,
> +		.is_external = true,
> +	},
> +	[1] = {
> +		.name = "external-falling",
> +		.value = AT91_TSADCC_TRGMOD_EXT_FALLING,
> +		.is_external = true,
> +	},
> +	[2] = {
> +		.name = "external-any",
> +		.value = AT91_TSADCC_TRGMOD_EXT_ANY,
> +		.is_external = true,
> +	},
> +	[3] = {
> +		.name = "continuous",
> +		.value = AT91_TSADCC_TRGMOD_CONTINUOUS,
> +		.is_external = false,
> +	},
> +	[4] = {
> +		.name = NULL,
> +	},
> +};
> +
>  static struct at91_adc_desc at91_adc_desc_sam9g45 = {
>  	.clock = 13200000,
>  	.clock_name = "tsc_clk",
>  	.num_channels = 8,
>  	.startup_time = 40,
> +	.triggers = at91_adc_trigger_sam9g45,
> +	.trigger_register = AT91_TSADCC_TRGR,
> +};
> +
> +static struct at91_adc_trigger at91_adc_trigger_sam9g20[] = {
> +	[0] = {
> +		.name = "timer-counter-0",
> +		.value = AT91_ADC_TRGSEL_TC0 | AT91_ADC_TRGEN,
> +		.is_external = false,
> +	},
> +	[1] = {
> +		.name = "timer-counter-1",
> +		.value = AT91_ADC_TRGSEL_TC1 | AT91_ADC_TRGEN,
> +		.is_external = false,
> +	},
> +	[2] = {
> +		.name = "timer-counter-2",
> +		.value = AT91_ADC_TRGSEL_TC2 | AT91_ADC_TRGEN,
> +		.is_external = false,
> +	},
> +	[3] = {
> +		.name = "external",
> +		.value = AT91_ADC_TRGSEL_EXTERNAL | AT91_ADC_TRGEN,
> +		.is_external = true,
> +	},
> +	[4] = {
> +		.name = NULL,
> +	},
>  };
>  
>  static struct at91_adc_desc at91_adc_desc_sam9g20 = {
> @@ -68,6 +153,8 @@ static struct at91_adc_desc at91_adc_desc_sam9g20 = {
>  	.clock_name = "adc_clk",
>  	.num_channels = 4,
>  	.startup_time = 10,
> +	.triggers = at91_adc_trigger_sam9g20,
> +	.trigger_register = AT91_ADC_MR,
>  };
same comment as before this soc specific

Best Regards,
J.
>  
> @@ -125,8 +257,9 @@ static int at91_adc_channel_init(struct iio_dev *idev,
>  	int bit, idx = 0;
>  
>  	idev->num_channels = bitmap_weight(&pdata->channels_used,
> -					   st->desc->num_channels);
> -	chan_array = kcalloc(idev->num_channels, sizeof(struct iio_chan_spec),
> +					   st->desc->num_channels) + 1;
> +	chan_array = kcalloc(idev->num_channels + 1,
> +			     sizeof(struct iio_chan_spec),
>  			     GFP_KERNEL);
devm_kzalloc
>  
>  	if (chan_array == NULL)
> @@ -137,6 +270,7 @@ static int at91_adc_channel_init(struct iio_dev *idev,
>  		chan->type = IIO_VOLTAGE;
>  		chan->indexed = 1;
>  		chan->channel = bit;
> +		chan->scan_index = idx;
>  		chan->scan_type.sign = 'u';
>  		chan->scan_type.realbits = 10;
>  		chan->scan_type.storagebits = 16;
> @@ -144,6 +278,13 @@ static int at91_adc_channel_init(struct iio_dev *idev,
>  		idx++;
>  	}
Best Regards,
J.

[RFC] IIO: Add hardware triggers support to the AT91 ADC driver

[Maxime Ripard]

Hi list,

here is a patchset that adds the hardware triggers support to the at91_adc
driver that only supported software triggers so far.

Please note that this is NOT for inclusion, only for review for now, as there is
no support for buffers and triggers out of staging out of staging, and the first
patches only duplicate the at91_adc driver I submitted out of staging.

So basically, the important patches at the 4th and 5th.

The fourth rework the way I declared the platform_data, in a more DT-compliant
way. I needed it for the available triggers declaration. I will surely backport
this part soon to the out-of-staging driver, because it will certainly be useful
to it.

The fifth one adds the triggers and buffers support to the driver in itself.
While the whole dynamic triggers declaration might seem overkill for now as I
only support the sam9g20-ek board, support for other atmel boards will come soon
and I surely need that in place.
On the downside, it probably needs some more work. Jonathan suggested earlier
that kfifo is a more convenient backend for the buffer, so I might switch to it
in the future. Also, I have not been able to test the timer counters triggers,
only the external for now.

This patchset is based on the commit 3413ec44 from Jonathan's master tree.

So please, take a look.
Thanks,
Maxime

Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>

[PATCH 3/5] ARM: AT91: Add the ADC to the sam9g20ek board

[Maxime Ripard]

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 arch/arm/mach-at91/at91sam9260_devices.c |   62 ++++++++++++++++++++++++++++++
 arch/arm/mach-at91/board-sam9g20ek.c     |   13 ++++++
 2 files changed, 75 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index 24b6f8c..3575019 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -17,6 +17,8 @@
 #include <linux/platform_device.h>
 #include <linux/i2c-gpio.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/board.h>
 #include <mach/cpu.h>
 #include <mach/at91sam9260.h>
@@ -1320,6 +1322,66 @@ void __init at91_add_device_cf(struct at91_cf_data *data)
 void __init at91_add_device_cf(struct at91_cf_data * data) {}
 #endif
 
+/* --------------------------------------------------------------------
+ *  ADCs
+ * -------------------------------------------------------------------- */
+
+#if defined(CONFIG_AT91_ADC) || defined(CONFIG_AT91_ADC_MODULE)
+static struct at91_adc_data adc_data;
+
+static struct resource adc_resources[] = {
+	[0] = {
+		.start	= AT91SAM9260_BASE_ADC,
+		.end	= AT91SAM9260_BASE_ADC + SZ_16K - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+	[1] = {
+		.start	= AT91SAM9260_ID_ADC,
+		.end	= AT91SAM9260_ID_ADC,
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static struct platform_device at91_adc_device = {
+	.name		= "at91_adc",
+	.id		= -1,
+	.dev		= {
+				.platform_data		= &adc_data,
+	},
+	.resource	= adc_resources,
+	.num_resources	= ARRAY_SIZE(adc_resources),
+};
+
+void __init at91_add_device_adc(struct at91_adc_data *data)
+{
+	if (!data)
+		return;
+
+	if (test_bit(0, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC0, 0);
+	if (test_bit(1, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC1, 0);
+	if (test_bit(2, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC2, 0);
+	if (test_bit(3, &data->channels_used))
+		at91_set_A_periph(AT91_PIN_PC3, 0);
+
+	/*
+	 * The electrical characteristics part of the AT91SAM9G20 datasheet
+	 * sets the ADC clock to 5MHz.
+	 */
+	data->adc_clock = 5000000;
+
+	data->num_channels = 4;
+	data->startup_time = 10;
+
+	adc_data = *data;
+	platform_device_register(&at91_adc_device);
+}
+#else
+void __init at91_add_device_adc(struct at91_adc_data *data) {}
+#endif
+
 /* -------------------------------------------------------------------- */
 /*
  * These devices are always present and don't need any board-specific
diff --git a/arch/arm/mach-at91/board-sam9g20ek.c b/arch/arm/mach-at91/board-sam9g20ek.c
index 64fc75c..7758f34 100644
--- a/arch/arm/mach-at91/board-sam9g20ek.c
+++ b/arch/arm/mach-at91/board-sam9g20ek.c
@@ -32,6 +32,8 @@
 #include <linux/regulator/fixed.h>
 #include <linux/regulator/consumer.h>
 
+#include <linux/platform_data/at91_adc.h>
+
 #include <mach/hardware.h>
 #include <asm/setup.h>
 #include <asm/mach-types.h>
@@ -309,6 +311,15 @@ static void __init ek_add_device_buttons(void)
 static void __init ek_add_device_buttons(void) {}
 #endif
 
+/*
+ * ADCs
+ */
+
+static struct at91_adc_data ek_adc_data = {
+	.channels_used = BIT(0) | BIT(1) | BIT(2) | BIT(3),
+	.vref = 3300,
+};
+
 #if defined(CONFIG_REGULATOR_FIXED_VOLTAGE) || defined(CONFIG_REGULATOR_FIXED_VOLTAGE_MODULE)
 static struct regulator_consumer_supply ek_audio_consumer_supplies[] = {
 	REGULATOR_SUPPLY("AVDD", "0-001b"),
@@ -384,6 +395,8 @@ static void __init ek_board_init(void)
 	ek_add_device_gpio_leds();
 	/* Push Buttons */
 	ek_add_device_buttons();
+	/* ADCs */
+	at91_add_device_adc(&ek_adc_data);
 	/* PCK0 provides MCLK to the WM8731 */
 	at91_set_B_periph(AT91_PIN_PC1, 0);
 	/* SSC (for WM8731) */
-- 
1.7.4.1