Re: [PATCH] gpio: Enable pcf857x GPIO expander for Device Tree

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* Re: [PATCH] gpio: Enable pcf857x GPIO expander for Device Tree
       [not found] <1370527523-1030-1-git-send-email-archit@ti.com>
@ 2013-06-17  7:03 ` Archit Taneja
       [not found] ` <1377498081-16358-1-git-send-email-archit@ti.com>
  2013-08-27  5:27 ` [RESEND PATCH " Archit Taneja
  2 siblings, 0 replies; 6+ messages in thread
From: Archit Taneja @ 2013-06-17  7:03 UTC (permalink / raw)
  To: linus.walleij; +Cc: linux-omap, linux-doc, Grant Likely, devicetree-discuss

Hi Linus,

On Thursday 06 June 2013 07:35 PM, Archit Taneja wrote:
> Add code to parse the GPIO expander Device Tree node and extract platform data
> out of it, and populate the struct 'pcf857x_platform_data' maintained by the
> driver. This enables devices to reference the gpio expander from Device Tree.
>
> Add DT binding info in Documentation.

Any comments on this patch?

Thanks,
Archit

>
> CC: Grant Likely <grant.likely@secretlab.ca>
> Signed-off-by: Archit Taneja <archit@ti.com>
> ---
>   .../devicetree/bindings/gpio/gpio-pcf857x.txt      | 44 +++++++++++++++++
>   drivers/gpio/gpio-pcf857x.c                        | 57 ++++++++++++++++++++--
>   2 files changed, 97 insertions(+), 4 deletions(-)
>   create mode 100644 Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt
>
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt b/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt
> new file mode 100644
> index 0000000..0556512
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt
> @@ -0,0 +1,44 @@
> +PCF857x I2C based GPIO controller bindings
> +
> +Required properties:
> +- compatible:
> +  - "nxp,pca9670" for NXP PCA9670 8 bit I/O expander
> +  - "nxp,pca9672" for NXP PCA9672 8 bit I/O expander with interrupt
> +  - "nxp,pca9674" for NXP PCA9672 8 bit I/O expander with interrupt
> +  - "nxp,pca8574" for NXP PCA8574 8 bit I/O expander with interrupt
> +  - "nxp,pca8575" for NXP PCA8575 16 bit I/O expander with interrupt
> +  - "nxp,pca9671" for NXP PCA9671 16 bit I/O expander
> +  - "nxp,pca9673" for NXP PCA9673 16 bit I/O expander with interrupt
> +  - "nxp,pca9675" for NXP PCA9675 16 bit I/O expander with interrupt
> +  - "ti,pcf8574"  for TI PCF8574 8 bit I/O expander with interrupt
> +  - "ti,pcf8574a" for TI PCF8574A 8 bit I/O expander with interrupt
> +  - "ti,pcf8575"  for TI PCF8575 16 bit I/O expander with interrupt
> +  - "ti,tca9554"  for TI TCA9554 8 bit I/O expander with interrupt
> +  - "maxim,max7328" for MAXIM MAX7328 8 bit I/O expander with interrupt
> +  - "maxim,max7329" for MAXIM MAX7329 8 bit I/O expander with interrupt
> +- gpio-controller : Marks the device node as a GPIO controller.
> +- #gpio-cells : Should be two.
> +  - first cell is the pin number.
> +  - second cell is unused.
> +- interrupt-controller: Mark the device node as an interrupt controller.
> +- #interrupt-cells : Should be two.
> +  - first cell is the GPIO number.
> +  - second cell is unused.
> +- reg: I2C address of the chip.
> +
> +Device speific properties:
> +- n_latch:		optional bit-inverse of initial register value; if
> +			you leave this initialized to zero the driver will act
> +			like the chip was just reset.
> +
> +Example:
> +
> +pcf8575: pcf8575 {
> +	compatible = "ti,pcf8575";
> +	gpio-controller;
> +	#gpio-cells = <2>;
> +	interrupt-controller;
> +	#interrupt-cells = <2>;
> +	reg = <0x20>;
> +	n_latch = <0x0>;
> +};
> diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c
> index e8faf53..3435790 100644
> --- a/drivers/gpio/gpio-pcf857x.c
> +++ b/drivers/gpio/gpio-pcf857x.c
> @@ -21,6 +21,7 @@
>   #include <linux/kernel.h>
>   #include <linux/slab.h>
>   #include <linux/gpio.h>
> +#include <linux/of.h>
>   #include <linux/i2c.h>
>   #include <linux/i2c/pcf857x.h>
>   #include <linux/interrupt.h>
> @@ -255,17 +256,42 @@ fail:
>
>   /*-------------------------------------------------------------------------*/
>
> +static struct pcf857x_platform_data *of_gpio_pcf857x(struct device *dev)
> +{
> +	struct pcf857x_platform_data *pdata;
> +	int r;
> +
> +	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata)
> +		return NULL;
> +
> +	pdata->gpio_base = -1;
> +
> +	r = of_property_read_u32(dev->of_node, "n_latch", &pdata->n_latch);
> +	if (r) {
> +		dev_dbg(dev, "couldn't find n-latch, use default\n");
> +		pdata->n_latch = 0;
> +	}
> +
> +	return pdata;
> +}
> +
>   static int pcf857x_probe(struct i2c_client *client,
>   			 const struct i2c_device_id *id)
>   {
>   	struct pcf857x_platform_data	*pdata;
> +	struct device_node		*node;
>   	struct pcf857x			*gpio;
>   	int				status;
>
>   	pdata = client->dev.platform_data;
> -	if (!pdata) {
> +	node = client->dev.of_node;
> +
> +	if (!pdata && node)
> +		pdata = of_gpio_pcf857x(&client->dev);
> +
> +	if (!pdata)
>   		dev_dbg(&client->dev, "no platform data\n");
> -	}
>
>   	/* Allocate, initialize, and register this gpio_chip. */
>   	gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
> @@ -420,10 +446,33 @@ static int pcf857x_remove(struct i2c_client *client)
>   	return status;
>   }
>
> +static const struct of_device_id pcf857x_dt_ids[] = {
> +	{ .compatible = "nxp,pca9670", },
> +	{ .compatible = "nxp,pca9672", },
> +	{ .compatible = "nxp,pca9674", },
> +	{ .compatible = "nxp,pca8574", },
> +	{ .compatible = "nxp,pca8575", },
> +	{ .compatible = "nxp,pca9671", },
> +	{ .compatible = "nxp,pca9673", },
> +	{ .compatible = "nxp,pca9675", },
> +
> +	{ .compatible = "ti,pcf8574", },
> +	{ .compatible = "ti,pcf8574a", },
> +	{ .compatible = "ti,pcf8575", },
> +	{ .compatible = "ti,tca9554", },
> +
> +	{ .compatible = "maxim,max7328", },
> +	{ .compatible = "maxim,max7329", },
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, pcf857x_dt_ids);
> +
>   static struct i2c_driver pcf857x_driver = {
>   	.driver = {
> -		.name	= "pcf857x",
> -		.owner	= THIS_MODULE,
> +		.name		= "pcf857x",
> +		.owner		= THIS_MODULE,
> +		.of_match_table	= pcf857x_dt_ids,
>   	},
>   	.probe	= pcf857x_probe,
>   	.remove	= pcf857x_remove,
>


^ permalink raw reply	[flat|nested] 6+ messages in thread

[parent not found: <1377498081-16358-1-git-send-email-archit@ti.com>]

* Re: [PATCH v2] gpio: Enable pcf857x GPIO expander for Device Tree
       [not found] ` <1377498081-16358-1-git-send-email-archit@ti.com>
@ 2013-08-27  3:20   ` Linus Walleij
  2013-08-27  6:47     ` Laurent Pinchart
  0 siblings, 1 reply; 6+ messages in thread
From: Linus Walleij @ 2013-08-27  3:20 UTC (permalink / raw)
  To: Archit Taneja
  Cc: linux-doc@vger.kernel.org, Linux-OMAP, Grant Likely,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org

On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote:

> Add code to parse the GPIO expander Device Tree node and extract platform data
> out of it, and populate the struct 'pcf857x_platform_data' maintained by the
> driver. This enables devices to reference the gpio expander from Device Tree.
>
> Add DT binding info in Documentation.
>
> Signed-off-by: Archit Taneja <archit@ti.com>
> ---
> - v2 posted after quite a while, sorry for the delay!
>
> Changes in v2:
> - second gpeio-cell description corrected in Documentation
> - interrupt controller description removed for now, will be added in a follow
>   up patch
> - n_latch description updated

The devicetree portions of this patch needs to be reviewed by
devicetree@vger.kernel.org, so please repost including that
list.

Yours,
Linus Walleij

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] gpio: Enable pcf857x GPIO expander for Device Tree
  2013-08-27  3:20   ` [PATCH v2] " Linus Walleij
@ 2013-08-27  6:47     ` Laurent Pinchart
  2013-08-27  7:00       ` Archit Taneja
  0 siblings, 1 reply; 6+ messages in thread
From: Laurent Pinchart @ 2013-08-27  6:47 UTC (permalink / raw)
  To: Linus Walleij
  Cc: Archit Taneja, linux-doc@vger.kernel.org, Linux-OMAP,
	Grant Likely, linux-arm-kernel@lists.infradead.org,
	devicetree@vger.kernel.org

On Tuesday 27 August 2013 05:20:45 Linus Walleij wrote:
> On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote:
> > Add code to parse the GPIO expander Device Tree node and extract platform
> > data out of it, and populate the struct 'pcf857x_platform_data'
> > maintained by the driver. This enables devices to reference the gpio
> > expander from Device Tree.
> > 
> > Add DT binding info in Documentation.
> > 
> > Signed-off-by: Archit Taneja <archit@ti.com>
> > ---
> > - v2 posted after quite a while, sorry for the delay!
> > 
> > Changes in v2:
> > - second gpeio-cell description corrected in Documentation
> > - interrupt controller description removed for now, will be added in a
> >   follow up patch
> > - n_latch description updated

And it seems that the patch conflicts with

https://lkml.org/lkml/2013/8/26/248

:-/

If we end up merging this one, I'd like to at least rename the DT n-latch 
property to pin-initial-states as in my patch and update the documentation, as 
I find it more explicit.

> The devicetree portions of this patch needs to be reviewed by
> devicetree@vger.kernel.org, so please repost including that
> list.

-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] gpio: Enable pcf857x GPIO expander for Device Tree
  2013-08-27  6:47     ` Laurent Pinchart
@ 2013-08-27  7:00       ` Archit Taneja
  2013-08-27  7:58         ` Laurent Pinchart
  0 siblings, 1 reply; 6+ messages in thread
From: Archit Taneja @ 2013-08-27  7:00 UTC (permalink / raw)
  To: Laurent Pinchart
  Cc: Linus Walleij, linux-doc@vger.kernel.org, Linux-OMAP,
	Grant Likely, linux-arm-kernel@lists.infradead.org,
	devicetree@vger.kernel.org

On Tuesday 27 August 2013 12:17 PM, Laurent Pinchart wrote:
> On Tuesday 27 August 2013 05:20:45 Linus Walleij wrote:
>> On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote:
>>> Add code to parse the GPIO expander Device Tree node and extract platform
>>> data out of it, and populate the struct 'pcf857x_platform_data'
>>> maintained by the driver. This enables devices to reference the gpio
>>> expander from Device Tree.
>>>
>>> Add DT binding info in Documentation.
>>>
>>> Signed-off-by: Archit Taneja <archit@ti.com>
>>> ---
>>> - v2 posted after quite a while, sorry for the delay!
>>>
>>> Changes in v2:
>>> - second gpeio-cell description corrected in Documentation
>>> - interrupt controller description removed for now, will be added in a
>>>    follow up patch
>>> - n_latch description updated
>
> And it seems that the patch conflicts with
>
> https://lkml.org/lkml/2013/8/26/248
>
> :-/

:/

>
> If we end up merging this one, I'd like to at least rename the DT n-latch
> property to pin-initial-states as in my patch and update the documentation, as
> I find it more explicit.

I think your patch is cleaner and more descriptive. The only thing which 
I am not clear about in your patch is the extra work done in getting 
ngpio, that should be available in i2c_device_id pointer argument in 
probe(id points to the array pcf857x_id already available in the driver 
with the number of gpios for each chip variant).

Archit


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] gpio: Enable pcf857x GPIO expander for Device Tree
  2013-08-27  7:00       ` Archit Taneja
@ 2013-08-27  7:58         ` Laurent Pinchart
  0 siblings, 0 replies; 6+ messages in thread
From: Laurent Pinchart @ 2013-08-27  7:58 UTC (permalink / raw)
  To: Archit Taneja
  Cc: Linus Walleij, linux-doc@vger.kernel.org, Linux-OMAP,
	Grant Likely, linux-arm-kernel@lists.infradead.org,
	devicetree@vger.kernel.org

Hi Archit,

On Tuesday 27 August 2013 12:30:18 Archit Taneja wrote:
> On Tuesday 27 August 2013 12:17 PM, Laurent Pinchart wrote:
> > On Tuesday 27 August 2013 05:20:45 Linus Walleij wrote:
> >> On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote:
> >>> Add code to parse the GPIO expander Device Tree node and extract
> >>> platform
> >>> data out of it, and populate the struct 'pcf857x_platform_data'
> >>> maintained by the driver. This enables devices to reference the gpio
> >>> expander from Device Tree.
> >>> 
> >>> Add DT binding info in Documentation.
> >>> 
> >>> Signed-off-by: Archit Taneja <archit@ti.com>
> >>> ---
> >>> - v2 posted after quite a while, sorry for the delay!
> >>> 
> >>> Changes in v2:
> >>> - second gpeio-cell description corrected in Documentation
> >>> - interrupt controller description removed for now, will be added in a
> >>> 
> >>>    follow up patch
> >>> 
> >>> - n_latch description updated
> > 
> > And it seems that the patch conflicts with
> > 
> > https://lkml.org/lkml/2013/8/26/248
> > 
> > :-/
>
> :/
>
> > If we end up merging this one, I'd like to at least rename the DT n-latch
> > property to pin-initial-states as in my patch and update the
> > documentation, as I find it more explicit.
> 
> I think your patch is cleaner and more descriptive.

Thank you.

> The only thing which I am not clear about in your patch is the extra work
> done in getting ngpio, that should be available in i2c_device_id pointer
> argument in probe(id points to the array pcf857x_id already available in the
> driver with the number of gpios for each chip variant).

You're right. I'll fix that and repost.

-- 
Regards,

Laurent Pinchart


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [RESEND PATCH v2] gpio: Enable pcf857x GPIO expander for Device Tree
       [not found] <1370527523-1030-1-git-send-email-archit@ti.com>
  2013-06-17  7:03 ` [PATCH] gpio: Enable pcf857x GPIO expander for Device Tree Archit Taneja
       [not found] ` <1377498081-16358-1-git-send-email-archit@ti.com>
@ 2013-08-27  5:27 ` Archit Taneja
  2 siblings, 0 replies; 6+ messages in thread
From: Archit Taneja @ 2013-08-27  5:27 UTC (permalink / raw)
  To: linus.walleij
  Cc: linux-doc, linux-omap, grant.likely, linux-arm-kernel, devicetree,
	Archit Taneja

Add code to parse the GPIO expander Device Tree node and extract platform data
out of it, and populate the struct 'pcf857x_platform_data' maintained by the
driver. This enables devices to reference the gpio expander from Device Tree.

Add DT binding info in Documentation.

Signed-off-by: Archit Taneja <archit@ti.com>
---
- v2 posted after quite a while, sorry for the delay!

Changes in v2:
- second gpeio-cell description corrected in Documentation
- interrupt controller description removed for now, will be added in a follow
  up patch
- n_latch description updated

 .../devicetree/bindings/gpio/gpio-pcf857x.txt      | 41 ++++++++++++++++
 drivers/gpio/gpio-pcf857x.c                        | 57 ++++++++++++++++++++--
 2 files changed, 94 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt b/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt
new file mode 100644
index 0000000..504d114
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt
@@ -0,0 +1,41 @@
+PCF857x I2C based GPIO controller bindings
+
+Required properties:
+- compatible:
+  - "nxp,pca9670" for NXP PCA9670 8 bit I/O expander
+  - "nxp,pca9672" for NXP PCA9672 8 bit I/O expander with interrupt
+  - "nxp,pca9674" for NXP PCA9672 8 bit I/O expander with interrupt
+  - "nxp,pca8574" for NXP PCA8574 8 bit I/O expander with interrupt
+  - "nxp,pca8575" for NXP PCA8575 16 bit I/O expander with interrupt
+  - "nxp,pca9671" for NXP PCA9671 16 bit I/O expander
+  - "nxp,pca9673" for NXP PCA9673 16 bit I/O expander with interrupt
+  - "nxp,pca9675" for NXP PCA9675 16 bit I/O expander with interrupt
+  - "ti,pcf8574"  for TI PCF8574 8 bit I/O expander with interrupt
+  - "ti,pcf8574a" for TI PCF8574A 8 bit I/O expander with interrupt
+  - "ti,pcf8575"  for TI PCF8575 16 bit I/O expander with interrupt
+  - "ti,tca9554"  for TI TCA9554 8 bit I/O expander with interrupt
+  - "maxim,max7328" for MAXIM MAX7328 8 bit I/O expander with interrupt
+  - "maxim,max7329" for MAXIM MAX7329 8 bit I/O expander with interrupt
+- gpio-controller : Marks the device node as a GPIO controller.
+- #gpio-cells : Should be two.
+  - first cell is the pin number.
+  - second cell is used to specify optional parameters (currently unused, but
+    needed by gpiolib).
+- reg: I2C address of the chip.
+
+Device speific properties:
+- n_latch:		optional bit-inverse of initial register value; if
+			you leave this initialized to zero the driver will act
+			like the chip was just reset. If it is a non-zero
+			value, the driver will program the inverted value of
+			n_latch as the initial state of the gpios.
+
+Example:
+
+pcf8575: pcf8575 {
+	compatible = "ti,pcf8575";
+	gpio-controller;
+	#gpio-cells = <2>;
+	reg = <0x20>;
+	n_latch = <0x0>;
+};
diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c
index e8faf53..3435790 100644
--- a/drivers/gpio/gpio-pcf857x.c
+++ b/drivers/gpio/gpio-pcf857x.c
@@ -21,6 +21,7 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/gpio.h>
+#include <linux/of.h>
 #include <linux/i2c.h>
 #include <linux/i2c/pcf857x.h>
 #include <linux/interrupt.h>
@@ -255,17 +256,42 @@ fail:
 
 /*-------------------------------------------------------------------------*/
 
+static struct pcf857x_platform_data *of_gpio_pcf857x(struct device *dev)
+{
+	struct pcf857x_platform_data *pdata;
+	int r;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return NULL;
+
+	pdata->gpio_base = -1;
+
+	r = of_property_read_u32(dev->of_node, "n_latch", &pdata->n_latch);
+	if (r) {
+		dev_dbg(dev, "couldn't find n-latch, use default\n");
+		pdata->n_latch = 0;
+	}
+
+	return pdata;
+}
+
 static int pcf857x_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct pcf857x_platform_data	*pdata;
+	struct device_node		*node;
 	struct pcf857x			*gpio;
 	int				status;
 
 	pdata = client->dev.platform_data;
-	if (!pdata) {
+	node = client->dev.of_node;
+
+	if (!pdata && node)
+		pdata = of_gpio_pcf857x(&client->dev);
+
+	if (!pdata)
 		dev_dbg(&client->dev, "no platform data\n");
-	}
 
 	/* Allocate, initialize, and register this gpio_chip. */
 	gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
@@ -420,10 +446,33 @@ static int pcf857x_remove(struct i2c_client *client)
 	return status;
 }
 
+static const struct of_device_id pcf857x_dt_ids[] = {
+	{ .compatible = "nxp,pca9670", },
+	{ .compatible = "nxp,pca9672", },
+	{ .compatible = "nxp,pca9674", },
+	{ .compatible = "nxp,pca8574", },
+	{ .compatible = "nxp,pca8575", },
+	{ .compatible = "nxp,pca9671", },
+	{ .compatible = "nxp,pca9673", },
+	{ .compatible = "nxp,pca9675", },
+
+	{ .compatible = "ti,pcf8574", },
+	{ .compatible = "ti,pcf8574a", },
+	{ .compatible = "ti,pcf8575", },
+	{ .compatible = "ti,tca9554", },
+
+	{ .compatible = "maxim,max7328", },
+	{ .compatible = "maxim,max7329", },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, pcf857x_dt_ids);
+
 static struct i2c_driver pcf857x_driver = {
 	.driver = {
-		.name	= "pcf857x",
-		.owner	= THIS_MODULE,
+		.name		= "pcf857x",
+		.owner		= THIS_MODULE,
+		.of_match_table	= pcf857x_dt_ids,
 	},
 	.probe	= pcf857x_probe,
 	.remove	= pcf857x_remove,
-- 
1.8.1.2


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2013-08-27  7:58 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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     [not found] <1370527523-1030-1-git-send-email-archit@ti.com>
2013-06-17  7:03 ` [PATCH] gpio: Enable pcf857x GPIO expander for Device Tree Archit Taneja
     [not found] ` <1377498081-16358-1-git-send-email-archit@ti.com>
2013-08-27  3:20   ` [PATCH v2] " Linus Walleij
2013-08-27  6:47     ` Laurent Pinchart
2013-08-27  7:00       ` Archit Taneja
2013-08-27  7:58         ` Laurent Pinchart
2013-08-27  5:27 ` [RESEND PATCH " Archit Taneja

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