backlight: Add TPS65217 WLED driver

The TPS65217 chip contains a boost converter and current sinks which can be used to drive LEDs for use as backlights. Expose this functionality via the backlight API.

Tested on an AM335x based custom board with a single WLED string, using different values for ISEL and FDIM (though it would be hard to tell the difference except for the value in WLEDCTRL1). Both instantiation through the device tree and by passing platform data have been tested. Testing has been done with an Androidized 3.2 kernel from the rowboat project

This patch is based on the mfd tree, it also applies on linux-next (20120809)

drivers/mfd/tps65217.c +13 -0

@@ -174,6 +174,10 @@ static struct tps65217_board *tps65217_parse_dt(struct i2c_client *client)
 		pdata->of_node[i] = reg_matches[i].of_node;
 	}
 
+	node = of_find_node_by_name(node, "backlight");
+	if (node)
+		pdata->of_node[TPS65217_SUBDEV_BL] = node;
+
 	return pdata;
 }
 

@@ -250,7 +254,32 @@ static int __devinit tps65217_probe(struct i2c_client *client,
 		platform_device_add(pdev);
 	}
 
+	if (pdata->bl_pdata || pdata->of_node[TPS65217_SUBDEV_BL]) {
+		tps->bl_pdev = platform_device_alloc("tps65217-bl", 0);
+		if (!tps->bl_pdev) {
+			dev_err(tps->dev, "Cannot create backlight platform device\n");
+			ret = -ENOMEM;
+			goto err_alloc_bl_pdev;
+		}
+
+		tps->bl_pdev->dev.parent = tps->dev;

Quoted 4 lines

The TPS65217 chip contains a boost converter and current sinks which can be used to drive LEDs for use as backlights. Expose this functionality via the backlight API.

Quoted 7 lines

Tested on an AM335x based custom board with a single WLED string, using different values for ISEL and FDIM (though it would be hard to tell the difference except for the value in WLEDCTRL1). Both instantiation through the device tree and by passing platform data have been tested. Testing has been done with an Androidized 3.2 kernel from the rowboat project

This patch is based on the mfd tree, it also applies on linux-next (20120809)

It doesn't seem to apply to my for-next branch.

Also, some comments:

Quoted 29 lines

drivers/mfd/tps65217.c +18 -0

@@ -174,6 +174,10 @@ static struct tps65217_board *tps65217_parse_dt(struct i2c_client *client)
 		pdata->of_node[i] = reg_matches[i].of_node;
 	}
 
+	node = of_find_node_by_name(node, "backlight");
+	if (node)
+		pdata->of_node[TPS65217_SUBDEV_BL] = node;
+
 	return pdata;
 }
 

@@ -250,7 +254,32 @@ static int __devinit tps65217_probe(struct i2c_client *client,
 		platform_device_add(pdev);
 	}
 
+	if (pdata->bl_pdata || pdata->of_node[TPS65217_SUBDEV_BL]) {
+		tps->bl_pdev = platform_device_alloc("tps65217-bl", 0);
+		if (!tps->bl_pdev) {
+			dev_err(tps->dev, "Cannot create backlight platform device\n");
+			ret = -ENOMEM;
+			goto err_alloc_bl_pdev;
+		}
+
+		tps->bl_pdev->dev.parent = tps->dev;
+
+		if (pdata->bl_pdata)
+			tps->bl_pdev->dev.platform_data = pdata->bl_pdata;
+		else
+			tps->bl_pdev->dev.of_node =

drivers/mfd/tps65217.c static int __devinit tps65217_probe(struct i2c_client *client, · line 275

Quoted 5 lines

drivers/mfd/tps65217.c +5 -0

+				pdata->of_node[TPS65217_SUBDEV_BL];
+
+		platform_device_add(tps->bl_pdev);
+	}
+

The MFD API probably allows you to do exactly that by defining a specific cell for bl. Could you please try to use this API or otherwise justify not using it?

Quoted 3 lines

The MFD API probably allows you to do exactly that by defining a specific cell for bl. Could you please try to use this API or otherwise justify not using it?

you seem to have missed v3 of the patch which addresses this, it was sent on 22 Aug 2012

in the next days i'll submit v4, with changes based on the comments received for v3