[PATCH v2] media: rc: gpio-ir-recv: add support for device tree parsing

[Sebastian Hesselbarth]

On 02/08/2013 10:26 PM, Sylwester Nawrocki wrote:
> On 02/08/2013 09:38 PM, Sebastian Hesselbarth wrote:
>> This patch adds device tree parsing for gpio_ir_recv platform_data and
>> the mandatory binding documentation. It basically follows what we already
>> have for e.g. gpio_keys. All required device tree properties are OS
>> independent but an optional property allow linux specific support for rc
>> maps.
>>
>> There was a similar patch sent by Matus Ujhelyi but that discussion
>> died after the first reviews.
>>
>> Signed-off-by: Sebastian Hesselbarth<sebastian.hesselbarth at gmail.com>
>> ---
>> Changelog
>>
>> v1->v2:
>> - get rid of ptr returned by _get_devtree_pdata()
>> - check for of_node instead for NULL pdata
>> - remove unneccessary double check for gpios property
>> - remove unneccessary #ifdef CONFIG_OF around match table
>>
>> Cc: Grant Likely<grant.likely at secretlab.ca>
>> Cc: Rob Herring<rob.herring at calxeda.com>
>> Cc: Rob Landley<rob at landley.net>
>> Cc: Mauro Carvalho Chehab<mchehab at redhat.com>
>> Cc: Sebastian Hesselbarth<sebastian.hesselbarth at gmail.com>
>> Cc: Benoit Thebaudeau<benoit.thebaudeau at advansee.com>
>> Cc: David Hardeman<david at hardeman.nu>
>> Cc: Trilok Soni<tsoni at codeaurora.org>
>> Cc: Sylwester Nawrocki<s.nawrocki at samsung.com>
>> Cc: Matus Ujhelyi<ujhelyi.m at gmail.com>
>> Cc: devicetree-discuss at lists.ozlabs.org
>> Cc: linux-doc at vger.kernel.org
>> Cc: linux-kernel at vger.kernel.org
>> Cc: linux-media at vger.kernel.org
>> ---
>> .../devicetree/bindings/media/gpio-ir-receiver.txt | 16 ++++++
>> drivers/media/rc/gpio-ir-recv.c | 57 ++++++++++++++++++++
>> 2 files changed, 73 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
>>
>> diff --git a/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
>> b/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
>> new file mode 100644
>> index 0000000..8589f30
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/gpio-ir-receiver.txt
>> @@ -0,0 +1,16 @@
>> +Device-Tree bindings for GPIO IR receiver
>> +
>> +Required properties:
>> + - compatible = "gpio-ir-receiver";
>> + - gpios: OF device-tree gpio specification.
>
> Perhaps:
> - compatible: should be "gpio-ir-receiver";
> - gpios: specifies GPIO used for IR signal reception.
> ?

Ok, i'll change that.

>> +
>> +Optional properties:
>> + - linux,rc-map-name: Linux specific remote control map name.
>> +
>> +Example node:
>> +
>> + ir: ir-receiver {
>> + compatible = "gpio-ir-receiver";
>> + gpios =<&gpio0 19 1>;
>> + linux,rc-map-name = "rc-rc6-mce";
>> + };
>> diff --git a/drivers/media/rc/gpio-ir-recv.c b/drivers/media/rc/gpio-ir-recv.c
>> index 4f71a7d..3c62006 100644
>> --- a/drivers/media/rc/gpio-ir-recv.c
>> +++ b/drivers/media/rc/gpio-ir-recv.c
>> @@ -16,6 +16,7 @@
>> #include<linux/interrupt.h>
>> #include<linux/gpio.h>
>> #include<linux/slab.h>
>> +#include<linux/of_gpio.h>
>> #include<linux/platform_device.h>
>> #include<linux/irq.h>
>> #include<media/rc-core.h>
>> @@ -30,6 +31,50 @@ struct gpio_rc_dev {
>> bool active_low;
>> };
>>
>> +#ifdef CONFIG_OF
>> +/*
>> + * Translate OpenFirmware node properties into platform_data
>> + */
>> +static int gpio_ir_recv_get_devtree_pdata(struct device *dev,
>> + struct gpio_ir_recv_platform_data *pdata)
>> +{
>> + struct device_node *np = dev->of_node;
>> + enum of_gpio_flags flags;
>> + int gpio;
>> +
>> + gpio = of_get_gpio_flags(np, 0,&flags);
>> + if (gpio< 0) {
>> + if (gpio != -EPROBE_DEFER)
>> + dev_err(dev, "Failed to get gpio flags, error: %d\n",
>> + gpio);
>
> dev_err(dev, "Failed to get gpio flags (%d)\n", gpio);
> ?

Ack.

>> + return gpio;
>> + }
>> +
>> + pdata->gpio_nr = gpio;
>> + pdata->active_low = (flags& OF_GPIO_ACTIVE_LOW) ? true : false;
>
> This could be simplified to:
>
> pdata->active_low = (flags & OF_GPIO_ACTIVE_LOW);

Ack.

>> + /* probe() takes care of map_name == NULL or allowed_protos == 0 */
>> + pdata->map_name = of_get_property(np, "linux,rc-map-name", NULL);
>> + pdata->allowed_protos = 0;
>> +
>> + return 0;
>> +}
>> +
>> +static struct of_device_id gpio_ir_recv_of_match[] = {
>> + { .compatible = "gpio-ir-receiver", },
>> + { },
>> +};
>> +MODULE_DEVICE_TABLE(of, gpio_ir_recv_of_match);
>> +
>> +#else /* !CONFIG_OF */
>> +
>> +static inline struct gpio_ir_recv_platform_data *
>> +gpio_ir_recv_get_devtree_pdata(struct device *dev)
>
> Please check how it compiles with CONFIG_OF disabled ;)

Grrrml ;) I'll fix that of course...

> You could also make it:
>
> #define gpio_ir_recv_get_devtree_pdata (-ENOSYS)

Hmm, does that also play with parameter passing of the
CONFIG_OF gpio_ir_recv_get_devtree_pdata() ?

>> +{
>> + return ERR_PTR(-ENODEV);
>> +}
>> +
>> +#endif
>> +
>> static irqreturn_t gpio_ir_recv_irq(int irq, void *dev_id)
>> {
>> struct gpio_rc_dev *gpio_dev = dev_id;
>> @@ -66,6 +111,17 @@ static int gpio_ir_recv_probe(struct platform_device *pdev)
>> pdev->dev.platform_data;
>> int rc;
>>
>> + if (pdev->dev.of_node) {
>> + struct gpio_ir_recv_platform_data *dtpdata =
>
> I think you could use pdata here instead, as previously. But I'm fine with
> as it is now as well.

Yeah, but pdata is const and I will change it within _get_devtree_pdata().
I could cast the const away when passing it to gpio_ir_recv_get_devtree_pdata()
but it is almost the same amount of code.. and it is cleaner this way.

>
>> + devm_kzalloc(&pdev->dev, sizeof(*dtpdata), GFP_KERNEL);
>> + if (!dtpdata)
>> + return -ENOMEM;
>> + rc = gpio_ir_recv_get_devtree_pdata(&pdev->dev, dtpdata);
>> + if (rc)
>> + return rc;
>> + pdata = dtpdata;
>> + }
>> +
>> if (!pdata)
>> return -EINVAL;
>>
>> @@ -192,6 +248,7 @@ static struct platform_driver gpio_ir_recv_driver = {
>> .driver = {
>> .name = GPIO_IR_DRIVER_NAME,
>> .owner = THIS_MODULE,
>> + .of_match_table = of_match_ptr(gpio_ir_recv_of_match),
>> #ifdef CONFIG_PM
>> .pm =&gpio_ir_recv_pm_ops,
>> #endif
>
> The patch looks good to me in general, after fixing the empty function
> declaration please feel free to add:
>
> Reviewed-by: Sylwester Nawrocki <s.nawrocki at samsung.com>

Thanks for the review (again),

I'll push a v3 with your remarks today or tomorrow.

Sebastian