[PATCH] ARM: pcm037: convert custom GPIO-based power function to a regulator

[PATCH] ARM: pcm037: convert custom GPIO-based power function to a regulator

[Guennadi Liakhovetski]

Add a fixed-voltage GPIO-enabled regulator to switch the camera on and off
instead of using a .power() platform callback.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
---

Only tested to grab the regulator during probing, couldn't test 
functionality due to the lack of an mt9t031 sensor.

 arch/arm/mach-imx/mach-pcm037.c |   50 ++++++++++++++++++++++++++++-----------
 1 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-imx/mach-pcm037.c b/arch/arm/mach-imx/mach-pcm037.c
index 639a3df..6c19eb1 100644
--- a/arch/arm/mach-imx/mach-pcm037.c
+++ b/arch/arm/mach-imx/mach-pcm037.c
@@ -288,12 +288,39 @@ static struct at24_platform_data board_eeprom = {
 	.flags = AT24_FLAG_ADDR16,
 };
 
-static int pcm037_camera_power(struct device *dev, int on)
-{
-	/* disable or enable the camera in X7 or X8 PCM970 connector */
-	gpio_set_value(IOMUX_TO_GPIO(MX31_PIN_CSI_D5), !on);
-	return 0;
-}
+/* Fixed 3.3V regulator to be used by cameras */
+static struct regulator_consumer_supply vcc_cam_consumers[] = {
+	REGULATOR_SUPPLY("vcc", "soc-camera-pdrv.0"),
+};
+
+static struct regulator_init_data vcc_cam_init_data = {
+	.constraints = {
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies  = ARRAY_SIZE(vcc_cam_consumers),
+	.consumer_supplies      = vcc_cam_consumers,
+};
+
+static struct fixed_voltage_config vcc_cam_info = {
+	.supply_name = "Camera Vcc",
+	.microvolts = 2800000,
+	.gpio = IOMUX_TO_GPIO(MX31_PIN_CSI_D5),
+	.init_data = &vcc_cam_init_data,
+};
+
+static struct platform_device vcc_cam = {
+	.name = "reg-fixed-voltage",
+	.id   = 1,
+	.dev  = {
+		.platform_data = &vcc_cam_info,
+	},
+};
+
+static struct regulator_bulk_data cam_supply[] = {
+	{
+		.supply = "vcc",
+	},
+};
 
 static struct i2c_board_info pcm037_i2c_camera[] = {
 	{
@@ -311,7 +338,8 @@ static struct soc_camera_link iclink_mt9v022 = {
 
 static struct soc_camera_link iclink_mt9t031 = {
 	.bus_id		= 0,		/* Must match with the camera ID */
-	.power		= pcm037_camera_power,
+	.num_regulators	= ARRAY_SIZE(cam_supply),
+	.regulators	= cam_supply,
 	.board_info	= &pcm037_i2c_camera[0],
 	.i2c_adapter_id	= 2,
 };
@@ -436,6 +464,7 @@ err:
 static struct platform_device *devices[] __initdata = {
 	&pcm037_flash,
 	&pcm037_sram_device,
+	&vcc_cam,
 	&pcm037_mt9t031,
 	&pcm037_mt9v022,
 };
@@ -647,13 +676,6 @@ static void __init pcm037_init(void)
 	imx31_add_mx3_sdc_fb(&mx3fb_pdata);
 
 	/* CSI */
-	/* Camera power: default - off */
-	ret = gpio_request(IOMUX_TO_GPIO(MX31_PIN_CSI_D5), "mt9t031-power");
-	if (!ret)
-		gpio_direction_output(IOMUX_TO_GPIO(MX31_PIN_CSI_D5), 1);
-	else
-		iclink_mt9t031.power = NULL;
-
 	pcm037_init_camera();
 
 	pcm970_sja1000_resources[1].start =
-- 
1.7.2.5

[PATCH] ARM: pcm037: convert custom GPIO-based power function to a regulator

[Sascha Hauer]

Hi Guennadi,

On Thu, Oct 31, 2013 at 11:20:46AM +0100, Guennadi Liakhovetski wrote:
> Add a fixed-voltage GPIO-enabled regulator to switch the camera on and off
> instead of using a .power() platform callback.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
> 
> Only tested to grab the regulator during probing, couldn't test 
> functionality due to the lack of an mt9t031 sensor.
> 
>  arch/arm/mach-imx/mach-pcm037.c |   50 ++++++++++++++++++++++++++++-----------
>  1 files changed, 36 insertions(+), 14 deletions(-)

What's the motivation for this patch? It probably does the right thing,
but I think we need a plan for converting this to devicetree rather than
adding more stuff.

Sascha

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[PATCH] ARM: pcm037: convert custom GPIO-based power function to a regulator

[Guennadi Liakhovetski]

Hi Sascha,

On Mon, 4 Nov 2013, Sascha Hauer wrote:

> Hi Guennadi,
> 
> On Thu, Oct 31, 2013 at 11:20:46AM +0100, Guennadi Liakhovetski wrote:
> > Add a fixed-voltage GPIO-enabled regulator to switch the camera on and off
> > instead of using a .power() platform callback.
> > 
> > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> > ---
> > 
> > Only tested to grab the regulator during probing, couldn't test 
> > functionality due to the lack of an mt9t031 sensor.
> > 
> >  arch/arm/mach-imx/mach-pcm037.c |   50 ++++++++++++++++++++++++++++-----------
> >  1 files changed, 36 insertions(+), 14 deletions(-)
> 
> What's the motivation for this patch? It probably does the right thing,
> but I think we need a plan for converting this to devicetree rather than
> adding more stuff.

It's not adding stuff. It's getting rid of a custom callback and replacing 
it with a proper regulator. Sure, if there's a plan to port this platform 
to DT in a foreseeable future - feel free to drop this. But such a port 
would require adding DT support to the mx3_camera driver / the soc-camera 
framework, which might take some time, and this board isn't too new 
either, so, maybe not many customers will be prepared to pay for that kind 
of work ;) Anyway, I find this useful in its present form, but if there 
are plans to switch to DT soon enough - no problem with dropping it 
either.

Thanks
Guennadi

> Sascha

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/