[PATCH 2/9] ARM: AT91: IIO: Add AT91 ADC driver.
Jonathan Cameron
jic23 at cam.ac.uk
Wed May 9 10:25:45 EDT 2012
On 5/9/2012 2:02 PM, Maxime Ripard wrote:
> Add the ADC driver for Atmel's AT91SAM9G20-EK, AT91SAM9M10G45-EK
> and AT91SAM9X5 family boards.
>
> It has support for both software and hardware triggers.
Totally trivial, but please add a newline where it says below.
Otherwise, looks
fine to me. Couple of other passing comments inline, but nothing else
to change
unless you particularly want to.
> Signed-off-by: Maxime Ripard<maxime.ripard at free-electrons.com>
> Acked-by: Nicolas Ferre<nicolas.ferre at atmel.com>
Acked-by: Jonathan Cameron <jic23 at kernel.org>
> ---
> drivers/iio/Kconfig | 2 +
> drivers/iio/Makefile | 2 +
> drivers/iio/adc/Kconfig | 16 ++
> drivers/iio/adc/Makefile | 5 +
> drivers/iio/adc/at91_adc.c | 673 ++++++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 698 insertions(+)
> create mode 100644 drivers/iio/adc/Kconfig
> create mode 100644 drivers/iio/adc/Makefile
> create mode 100644 drivers/iio/adc/at91_adc.c
>
> diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
> index 3ab7d48..47e0920 100644
> --- a/drivers/iio/Kconfig
> +++ b/drivers/iio/Kconfig
> @@ -48,4 +48,6 @@ config IIO_CONSUMERS_PER_TRIGGER
> This value controls the maximum number of consumers that a
> given trigger may handle. Default is 2.
>
> +source "drivers/iio/adc/Kconfig"
> +
> endif # IIO
> diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
> index d5fc57d..eb926a2 100644
> --- a/drivers/iio/Makefile
> +++ b/drivers/iio/Makefile
> @@ -8,3 +8,5 @@ industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
> industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
>
> obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
> +
> +obj-y += adc/
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> new file mode 100644
> index 0000000..9a0df81
> --- /dev/null
> +++ b/drivers/iio/adc/Kconfig
> @@ -0,0 +1,16 @@
> +#
> +# ADC drivers
> +#
> +menu "Analog to digital converters"
> +
> +config AT91_ADC
> + tristate "Atmel AT91 ADC"
> + depends on ARCH_AT91
> + select IIO_BUFFER
> + select IIO_KFIFO_BUF
> + select IIO_TRIGGER
> + select SYSFS
> + help
> + Say yes here to build support for Atmel AT91 ADC.
> +
> +endmenu
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> new file mode 100644
> index 0000000..b62d488
> --- /dev/null
> +++ b/drivers/iio/adc/Makefile
> @@ -0,0 +1,5 @@
> +#
> +# Makefile for IIO ADC drivers
> +#
> +
> +obj-$(CONFIG_AT91_ADC) += at91_adc.o
Please add a newline here.
> \ No newline at end of file
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> new file mode 100644
> index 0000000..e5d73b1
> --- /dev/null
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -0,0 +1,673 @@
> +/*
> + * 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<linux/platform_data/at91_adc.h>
> +
> +#include<linux/iio/iio.h>
> +#include<linux/iio/buffer.h>
> +#include<linux/iio/kfifo_buf.h>
> +#include<linux/iio/trigger.h>
> +#include<linux/iio/trigger_consumer.h>
> +
> +#include<mach/at91_adc.h>
> +
> +#define AT91_ADC_CHAN(st, ch) \
> + (st->registers->channel_base + (ch * 4))
> +#define at91_adc_readl(st, reg) \
> + (readl_relaxed(st->reg_base + reg))
> +#define at91_adc_writel(st, reg, val) \
> + (writel_relaxed(val, st->reg_base + reg))
> +
> +struct at91_adc_state {
> + struct clk *adc_clk;
> + u16 *buffer;
> + unsigned long channels_mask;
> + struct clk *clk;
> + bool done;
> + int irq;
> + bool irq_enabled;
> + u16 last_value;
> + struct mutex lock;
> + u8 num_channels;
> + void __iomem *reg_base;
> + struct at91_adc_reg_desc *registers;
> + u8 startup_time;
> + struct iio_trigger **trig;
> + struct at91_adc_trigger *trigger_list;
> + u32 trigger_number;
> + bool use_external;
> + u32 vref_mv;
> + wait_queue_head_t wq_data_avail;
> +};
> +
> +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 i, j = 0;
> +
> + for (i = 0; i< idev->masklength; i++) {
> + if (!test_bit(i, idev->active_scan_mask))
> + continue;
> + st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
> + j++;
> + }
> +
> + if (idev->scan_timestamp) {
> + s64 *timestamp = (s64 *)((u8 *)st->buffer +
> + ALIGN(j, 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_readl(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;
> + struct at91_adc_state *st = iio_priv(idev);
> + u32 status = at91_adc_readl(st, st->registers->status_register);
> +
> + if (!(status& st->registers->drdy_mask))
> + return IRQ_HANDLED;
> +
> + 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_readl(st, AT91_ADC_LCDR);
> + st->done = true;
> + wake_up_interruptible(&st->wq_data_avail);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int at91_adc_channel_init(struct iio_dev *idev)
> +{
> + struct at91_adc_state *st = iio_priv(idev);
> + struct iio_chan_spec *chan_array, *timestamp;
> + int bit, idx = 0;
> +
> + idev->num_channels = bitmap_weight(&st->channels_mask,
> + st->num_channels) + 1;
> +
> + chan_array = devm_kzalloc(&idev->dev,
> + ((idev->num_channels + 1) *
> + sizeof(struct iio_chan_spec)),
> + GFP_KERNEL);
> +
> + if (!chan_array)
> + return -ENOMEM;
> +
> + for_each_set_bit(bit,&st->channels_mask, st->num_channels) {
> + struct iio_chan_spec *chan = chan_array + idx;
> +
> + 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;
> + chan->info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT |
> + IIO_CHAN_INFO_RAW_SEPARATE_BIT;
> + idx++;
> + }
> + timestamp = chan_array + idx;
> +
> + timestamp->type = IIO_TIMESTAMP;
> + timestamp->channel = -1;
> + timestamp->scan_index = idx;
> + timestamp->scan_type.sign = 's';
> + timestamp->scan_type.realbits = 64;
> + timestamp->scan_type.storagebits = 64;
> +
> + idev->channels = chan_array;
> + return idev->num_channels;
> +}
> +
> +static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
> + struct at91_adc_trigger *triggers,
> + const char *trigger_name)
> +{
> + struct at91_adc_state *st = iio_priv(idev);
> + u8 value = 0;
> + int i;
> +
> + for (i = 0; i< st->trigger_number; i++) {
> + char *name = kasprintf(GFP_KERNEL,
> + "%s-dev%d-%s",
> + idev->name,
> + idev->id,
> + triggers[i].name);
> + if (!name)
> + 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;
> + struct at91_adc_reg_desc *reg = st->registers;
> + u32 status = at91_adc_readl(st, reg->trigger_register);
> + u8 value;
> + u8 bit;
> +
> + value = at91_adc_get_trigger_value_by_name(idev,
> + st->trigger_list,
> + idev->trig->name);
> + if (value == 0)
> + return -EINVAL;
> +
> + if (state) {
> + st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
> + if (st->buffer == NULL)
> + return -ENOMEM;
> +
> + at91_adc_writel(st, reg->trigger_register,
> + status | value);
> +
> + for_each_set_bit(bit, buffer->scan_mask,
> + st->num_channels) {
> + struct iio_chan_spec const *chan = idev->channels + bit;
> + at91_adc_writel(st, AT91_ADC_CHER,
> + AT91_ADC_CH(chan->channel));
> + }
> +
> + at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
> +
> + } else {
> + at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
> +
> + at91_adc_writel(st, reg->trigger_register,
> + status& ~value);
> +
> + for_each_set_bit(bit, buffer->scan_mask,
> + st->num_channels) {
> + struct iio_chan_spec const *chan = idev->channels + bit;
> + at91_adc_writel(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;
> + int ret;
> +
> + trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
> + idev->id, trigger->name);
> + 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)
> + return NULL;
> +
> + return trig;
> +}
> +
> +static int at91_adc_trigger_init(struct iio_dev *idev)
> +{
> + struct at91_adc_state *st = iio_priv(idev);
> + int i, ret;
> +
> + st->trig = devm_kzalloc(&idev->dev,
> + st->trigger_number * sizeof(st->trig),
> + GFP_KERNEL);
> +
> + if (st->trig == NULL) {
> + ret = -ENOMEM;
> + goto error_ret;
> + }
> +
> + for (i = 0; i< st->trigger_number; i++) {
> + if (st->trigger_list[i].is_external&& !(st->use_external))
> + continue;
> +
> + st->trig[i] = at91_adc_allocate_trigger(idev,
> + st->trigger_list + 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_trigger_free(st->trig[i]);
> + }
> +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; i< st->trigger_number; i++) {
> + iio_trigger_unregister(st->trig[i]);
> + iio_trigger_free(st->trig[i]);
> + }
> +}
> +
> +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_kfifo_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_kfifo_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_kfifo_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)
> +{
> + struct at91_adc_state *st = iio_priv(idev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + mutex_lock(&st->lock);
> +
> + at91_adc_writel(st, AT91_ADC_CHER,
> + AT91_ADC_CH(chan->channel));
> + at91_adc_writel(st, AT91_ADC_IER, st->registers->drdy_mask);
> + at91_adc_writel(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_writel(st, AT91_ADC_CHDR,
> + AT91_ADC_CH(chan->channel));
> + at91_adc_writel(st, AT91_ADC_IDR, st->registers->drdy_mask);
> +
> + 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 int at91_adc_probe_pdata(struct at91_adc_state *st,
> + struct platform_device *pdev)
> +{
> + struct at91_adc_data *pdata = pdev->dev.platform_data;
> +
> + if (!pdata)
> + return -EINVAL;
> +
This does look rather like it would be better to just keep a copy of
pdata around...
Still, not critical at all.
> + st->use_external = pdata->use_external_triggers;
> + st->vref_mv = pdata->vref;
> + st->channels_mask = pdata->channels_used;
> + st->num_channels = pdata->num_channels;
> + st->startup_time = pdata->startup_time;
> + st->trigger_number = pdata->trigger_number;
> + st->trigger_list = pdata->trigger_list;
> + st->registers = pdata->registers;
> +
> + return 0;
> +}
> +
> +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, adc_clk;
> + int ret;
> + struct iio_dev *idev;
> + struct at91_adc_state *st;
> + struct resource *res;
> +
> + idev = iio_device_alloc(sizeof(struct at91_adc_state));
> + if (idev == NULL) {
> + ret = -ENOMEM;
> + goto error_ret;
> + }
> +
> + st = iio_priv(idev);
> +
> + ret = at91_adc_probe_pdata(st, pdev);
> + if (ret) {
> + dev_err(&pdev->dev, "No platform data available.\n");
> + ret = -EINVAL;
> + goto error_free_device;
> + }
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "No resource defined\n");
> + ret = -ENXIO;
> + 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->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_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
> + at91_adc_writel(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, "adc_clk");
> + if (IS_ERR(st->clk)) {
> + dev_err(&pdev->dev, "Failed to get the clock.\n");
> + ret = PTR_ERR(st->clk);
> + goto error_free_irq;
> + }
> +
> + ret = clk_prepare(st->clk);
> + if (ret) {
> + dev_err(&pdev->dev, "Could not prepare the clock.\n");
> + goto error_free_clk;
> + }
> +
> + ret = clk_enable(st->clk);
> + if (ret) {
> + dev_err(&pdev->dev, "Could not enable the clock.\n");
> + goto error_unprepare_clk;
> + }
> +
> + st->adc_clk = clk_get(&pdev->dev, "adc_op_clk");
> + if (IS_ERR(st->adc_clk)) {
> + dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
> + ret = PTR_ERR(st->clk);
> + goto error_disable_clk;
> + }
> +
> + ret = clk_prepare(st->adc_clk);
> + if (ret) {
> + dev_err(&pdev->dev, "Could not prepare the ADC clock.\n");
> + goto error_free_adc_clk;
> + }
> +
> + ret = clk_enable(st->adc_clk);
> + if (ret) {
> + dev_err(&pdev->dev, "Could not enable the ADC clock.\n");
> + goto error_unprepare_adc_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.
> + */
> + mstrclk = clk_get_rate(st->clk);
> + adc_clk = clk_get_rate(st->adc_clk);
> + prsc = (mstrclk / (2 * adc_clk)) - 1;
> +
> + if (!st->startup_time) {
> + dev_err(&pdev->dev, "No startup time available.\n");
> + ret = -EINVAL;
> + goto error_disable_adc_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->startup_time * adc_clk /
> + 1000000) - 1, 8) / 8;
> + at91_adc_writel(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);
> + if (ret< 0) {
> + dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
> + goto error_disable_adc_clk;
> + }
> +
> + init_waitqueue_head(&st->wq_data_avail);
> + mutex_init(&st->lock);
> +
> + ret = at91_adc_buffer_init(idev);
> + if (ret< 0) {
> + dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
> + goto error_disable_adc_clk;
> + }
> +
> + ret = at91_adc_trigger_init(idev);
> + 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_remove_triggers;
> + }
> +
> + return 0;
> +
> +error_remove_triggers:
> + at91_adc_trigger_remove(idev);
> +error_unregister_buffer:
> + at91_adc_buffer_remove(idev);
> +error_disable_adc_clk:
> + clk_disable(st->adc_clk);
> +error_unprepare_adc_clk:
> + clk_unprepare(st->adc_clk);
> +error_free_adc_clk:
> + clk_put(st->adc_clk);
> +error_disable_clk:
> + clk_disable(st->clk);
> +error_unprepare_clk:
> + clk_unprepare(st->clk);
> +error_free_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_device_free(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_trigger_remove(idev);
> + at91_adc_buffer_remove(idev);
There is clk_disable_unprepare... Could use it though then it's not
quite as trivial to
check everything lines up between probe and remove.
> + clk_disable(st->adc_clk);
> + clk_unprepare(st->adc_clk);
> + clk_put(st->adc_clk);
> + clk_disable(st->clk);
> + clk_unprepare(st->clk);
> + clk_put(st->clk);
> + free_irq(st->irq, idev);
> + iounmap(st->reg_base);
> + release_mem_region(res->start, resource_size(res));
> + iio_device_free(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 at free-electrons.com>");
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