Thread (12 messages) 12 messages, 4 authors, 2015-01-18

Re: [PATCHv2] media: i2c/adp1653: devicetree support for adp1653

From: Sakari Ailus <hidden>
Date: 2014-12-30 13:57:39
Also in: linux-arm-kernel, linux-media, linux-omap, lkml

Hi Pavel,

Thanks for the patch! A few comments below.

On Wed, Dec 24, 2014 at 11:34:34PM +0100, Pavel Machek wrote:
quoted hunk ↗ jump to hunk
We are moving to device tree support on OMAP3, but that currently
breaks ADP1653 driver. This adds device tree support, plus required
documentation.

Signed-off-by: Pavel Machek <redacted>

---

Changed -microsec to -us, as requested by devicetree people.

Fixed checkpatch issues.
diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
index 2d88816..2c6c7c5 100644
--- a/Documentation/devicetree/bindings/leds/common.txt
+++ b/Documentation/devicetree/bindings/leds/common.txt
@@ -14,6 +14,15 @@ Optional properties for child nodes:
      "ide-disk" - LED indicates disk activity
      "timer" - LED flashes at a fixed, configurable rate
 
+- max-microamp : maximum intensity in microamperes of the LED
+	         (torch LED for flash devices)
s/torch LED/torch mode/
+- flash-max-microamp : maximum intensity in microamperes of the
+                       flash LED; it is mandatory if the LED should
+		       support the flash mode
+- flash-timeout-microsec : timeout in microseconds after which the flash
+                           LED is turned off
These should go to a different patch.
quoted hunk ↗ jump to hunk
+
+
 Examples:
 
 system-status {
@@ -21,3 +30,10 @@ system-status {
 	linux,default-trigger = "heartbeat";
 	...
 };
+
+camera-flash {
+	label = "Flash";
+	max-microamp = <50000>;
+	flash-max-microamp = <320000>;
+	flash-timeout-microsec = <500000>;
+}
diff --git a/Documentation/devicetree/bindings/media/i2c/adp1653.txt b/Documentation/devicetree/bindings/media/i2c/adp1653.txt
new file mode 100644
index 0000000..3c7065f
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/adp1653.txt
@@ -0,0 +1,38 @@
+* Analog Devices ADP1653 flash LED driver
+
+Required Properties:
+
+  - compatible: Must contain one of the following
+    - "adi,adp1653"
I doubt whether there are going to be more chips supported with the driver.
There hasn't been since the driver was written not I'm aware of one now.
+  - reg: I2C slave address
+
+  - gpios: References to the GPIO that controls the power for the chip.
+
+There are two led outputs available - flash and indicator. One led is
+represented by one child node, nodes need to be named "flash" and "indicator".
80 characters per line.
+
+Required properties of the LED child node:
+- max-microamp : see Documentation/devicetree/bindings/leds/common.txt
+
+Required properties of the flash LED child node:
+
+- flash-max-microamp : see Documentation/devicetree/bindings/leds/common.txt
+- flash-timeout-us : see Documentation/devicetree/bindings/leds/common.txt
+
+Example:
+
+        adp1653: led-controller@30 {
+                compatible = "adi,adp1653";
+		reg = <0x30>;
+                gpios = <&gpio3 24 GPIO_ACTIVE_HIGH>; /* 88 */
Please use tabs for indentation above (and below).
quoted hunk ↗ jump to hunk
+
+		flash {
+                        flash-timeout-us = <500000>;
+                        flash-max-microamp = <320000>;
+                        max-microamp = <50000>;
+		};
+                indicator {
+                        max-microamp = <17500>;
+		};
+        };
diff --git a/arch/arm/boot/dts/omap3-n900.dts b/arch/arm/boot/dts/omap3-n900.dts
index bc82a12..d04e7cc 100644
--- a/arch/arm/boot/dts/omap3-n900.dts
+++ b/arch/arm/boot/dts/omap3-n900.dts
@@ -553,6 +558,22 @@
 
 		ti,usb-charger-detection = <&isp1704>;
 	};
+
+	adp1653: led-controller@30 {
+		compatible = "adi,adp1653";
+		reg = <0x30>;
+		gpios = <&gpio3 24 GPIO_ACTIVE_HIGH>; /* 88 */
+
+		flash {
+			flash-timeout-us = <500000>;
+			flash-max-microamp = <320000>;
+			max-microamp = <50000>;
+		};
+
+		indicator {
+			max-microamp = <17500>;
+		};
+	};
This should go to a separate patch as well.
quoted hunk ↗ jump to hunk
 };
 
 &i2c3 {
diff --git a/drivers/media/i2c/adp1653.c b/drivers/media/i2c/adp1653.c
index 873fe19..78341d0 100644
--- a/drivers/media/i2c/adp1653.c
+++ b/drivers/media/i2c/adp1653.c
@@ -8,6 +8,7 @@
  * Contributors:
  *	Sakari Ailus <sakari.ailus-X3B1VOXEql0@public.gmane.org>
  *	Tuukka Toivonen <tuukkat76-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *      Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -34,9 +35,12 @@
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
+#include <linux/of_gpio.h>
 #include <media/adp1653.h>
 #include <media/v4l2-device.h>
 
+#include <linux/gpio.h>
Please arrange along with the rest of headers.
quoted hunk ↗ jump to hunk
+
 #define TIMEOUT_MAX		820000
 #define TIMEOUT_STEP		54600
 #define TIMEOUT_MIN		(TIMEOUT_MAX - ADP1653_REG_CONFIG_TMR_SET_MAX \
@@ -306,9 +318,18 @@ adp1653_init_device(struct adp1653_flash *flash)
 static int
 __adp1653_set_power(struct adp1653_flash *flash, int on)
 {
-	int ret;
+	int ret = 0;
+
+	if (flash->platform_data->power)
+		ret = flash->platform_data->power(&flash->subdev, on);
if () {
} else {
}
+	else {
+		gpio_set_value(flash->platform_data->power_gpio, on);
Shouldn't you add this to the platform data struct?

power_gpio is actually a poor name for this, as is the "power" callback.
This is really "EN" gpio in the spec, I'd call it perhaps just "gpio", or
"enable_gpio".
+		if (on) {
+			/* Some delay is apparently required. */
+			udelay(20);
The driver should always handle the delay, platform data or not. This
reminds me --- is there a need to retain the support for platform data? I
don't think it's being used anywhere. I'm fine with both keeping and
removing it.
quoted hunk ↗ jump to hunk
+		}
+	}
 
-	ret = flash->platform_data->power(&flash->subdev, on);
 	if (ret < 0)
 		return ret;
 
@@ -316,8 +337,13 @@ __adp1653_set_power(struct adp1653_flash *flash, int on)
 		return 0;
 
 	ret = adp1653_init_device(flash);
-	if (ret < 0)
+	if (ret >= 0)
+		return ret;
+
+	if (flash->platform_data->power)
 		flash->platform_data->power(&flash->subdev, 0);
+	else
+		gpio_set_value(flash->platform_data->power_gpio, 0);
 
 	return ret;
 }
@@ -407,21 +433,78 @@ static int adp1653_resume(struct device *dev)
 
 #endif /* CONFIG_PM */
 
+static int adp1653_of_init(struct i2c_client *client,
+			   struct adp1653_flash *flash,
+			   struct device_node *node)
+{
+	u32 val;
+	struct adp1653_platform_data *pd;
+	enum of_gpio_flags flags;
+	int gpio;
+	struct device_node *child;
+
+	if (!node)
+		return -EINVAL;
+
+	pd = devm_kzalloc(&client->dev, sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		return -ENOMEM;
+	flash->platform_data = pd;
+
+	child = of_get_child_by_name(node, "flash");
+	if (!child)
+		return -EINVAL;
+	if (of_property_read_u32(child, "flash-timeout-microsec", &val))
+		return -EINVAL;
+
+	pd->max_flash_timeout = val;
+	if (of_property_read_u32(child, "flash-max-microamp", &val))
+		return -EINVAL;
+	pd->max_flash_intensity = val/1000;
+
+	if (of_property_read_u32(child, "max-microamp", &val))
+		return -EINVAL;
+	pd->max_torch_intensity = val/1000;
+
+	child = of_get_child_by_name(node, "indicator");
+	if (!child)
+		return -EINVAL;
Do you require an indicator to be connected? I think it shouldn't be
mandatory, at least the driver should work without it, even if it exposes
the control (making that conditional would be a subject for another patch,
but that doesn't need to be done now).
+	if (of_property_read_u32(child, "max-microamp", &val))
+		return -EINVAL;
+	pd->max_indicator_intensity = val;
+
+	if (!of_find_property(node, "gpios", NULL)) {
+		dev_err(&client->dev, "No gpio node\n");
+		return -EINVAL;
+	}
+
+	gpio = of_get_gpio_flags(node, 0, &flags);
You could assign to pd->... here.
quoted hunk ↗ jump to hunk
+	if (gpio < 0) {
+		dev_err(&client->dev, "Error getting GPIO\n");
+		return -EINVAL;
+	}
+
+	pd->power_gpio = gpio;
+	return 0;
+}
+
+
 static int adp1653_probe(struct i2c_client *client,
 			 const struct i2c_device_id *devid)
 {
 	struct adp1653_flash *flash;
 	int ret;
 
-	/* we couldn't work without platform data */
-	if (client->dev.platform_data == NULL)
-		return -ENODEV;
-
 	flash = devm_kzalloc(&client->dev, sizeof(*flash), GFP_KERNEL);
 	if (flash == NULL)
 		return -ENOMEM;
 
 	flash->platform_data = client->dev.platform_data;
+	if (!flash->platform_data) {
+		ret = adp1653_of_init(client, flash, client->dev.of_node);
+		if (ret)
+			return ret;
+	}
 
 	mutex_init(&flash->power_lock);
 
@@ -438,10 +521,11 @@ static int adp1653_probe(struct i2c_client *client,
 		goto free_and_quit;
 
 	flash->subdev.entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;
-
+
Huh? :-)
quoted hunk ↗ jump to hunk
 	return 0;
 
 free_and_quit:
+	dev_err(&client->dev, "adp1653: failed to register device\n");
 	v4l2_ctrl_handler_free(&flash->ctrls);
 	return ret;
 }
@@ -464,7 +551,7 @@ static const struct i2c_device_id adp1653_id_table[] = {
 };
 MODULE_DEVICE_TABLE(i2c, adp1653_id_table);
 
-static struct dev_pm_ops adp1653_pm_ops = {
+static const struct dev_pm_ops adp1653_pm_ops = {
 	.suspend	= adp1653_suspend,
 	.resume		= adp1653_resume,
 };
-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus-X3B1VOXEql0@public.gmane.org	XMPP: sailus-PCDdDYkjdNMDXYZnReoRVg@public.gmane.org
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