Simple MFD base patches and cleanups:

- Document MFD DT bindings
 - Instantiate subdevices for simple MFDs
 - Switch Integrator and RealView to use the simple MFD
 - Augment LED driver to probe from platform device
 - Add LEDs to Juno Vexpress64
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Merge tag 'simple-mfd' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator into next/drivers

Merge "Simple MFD base patches and cleanups" from Linus Walleij:

- Document MFD DT bindings
- Instantiate subdevices for simple MFDs
- Switch Integrator and RealView to use the simple MFD
- Augment LED driver to probe from platform device
- Add LEDs to Juno Vexpress64

* tag 'simple-mfd' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator:
  arm64: add LEDs and some trigger support to defconfig
  arm64: juno: Add APB registers and LEDs using syscon
  leds: syscon: instantiate from platform device
  ARM: dts: update syscons to use simple-mfd
  MFD/OF: document MFD devices and handle simple-mfd

Documentation/devicetree/bindings/mfd/mfd.txt

@@ -0,0 +1,41 @@
+Multi-Function Devices (MFD)
+
+These devices comprise a nexus for heterogeneous hardware blocks containing
+more than one non-unique yet varying hardware functionality.
+
+A typical MFD can be:
+
+- A mixed signal ASIC on an external bus, sometimes a PMIC (Power Management
+  Integrated Circuit) that is manufactured in a lower technology node (rough
+  silicon) that handles analog drivers for things like audio amplifiers, LED
+  drivers, level shifters, PHY (physical interfaces to things like USB or
+  ethernet), regulators etc.
+
+- A range of memory registers containing "miscellaneous system registers" also
+  known as a system controller "syscon" or any other memory range containing a
+  mix of unrelated hardware devices.
+
+Optional properties:
+
+- compatible : "simple-mfd" - this signifies that the operating system should
+  consider all subnodes of the MFD device as separate devices akin to how
+  "simple-bus" inidicates when to see subnodes as children for a simple
+  memory-mapped bus. For more complex devices, when the nexus driver has to
+  probe registers to figure out what child devices exist etc, this should not
+  be used. In the latter case the child devices will be determined by the
+  operating system.
+
+Example:
+
+foo@1000 {
+	compatible = "syscon", "simple-mfd";
+	reg = <0x01000 0x1000>;
+
+	led@08.0 {
+		compatible = "register-bit-led";
+		offset = <0x08>;
+		mask = <0x01>;
+		label = "myled";
+		default-state = "on";
+	};
+};

arch/arm/boot/dts/arm-realview-pb1176.dts

@@ -114,7 +114,7 @@
 		ranges;
 
 		syscon: syscon@10000000 {
-			compatible = "arm,realview-pb1176-syscon", "syscon";
+			compatible = "arm,realview-pb1176-syscon", "syscon", "simple-mfd";
 			reg = <0x10000000 0x1000>;
 
 			led@08.0 {

arch/arm/boot/dts/integrator.dtsi

@@ -6,7 +6,7 @@
 
 / {
 	core-module@10000000 {
-		compatible = "arm,core-module-integrator", "syscon";
+		compatible = "arm,core-module-integrator", "syscon", "simple-mfd";
 		reg = <0x10000000 0x200>;
 
 		/* Use core module LED to indicate CPU load */
@@ -95,7 +95,7 @@
 
 		syscon {
 			/* Debug registers mapped as syscon */
-			compatible = "syscon";
+			compatible = "syscon", "simple-mfd";
 			reg = <0x1a000000 0x10>;
 
 			led@04.0 {

arch/arm64/boot/dts/arm/juno-motherboard.dtsi

@@ -66,6 +66,74 @@
 				#size-cells = <1>;
 				ranges = <0 3 0 0x200000>;
 
+				apbregs@010000 {
+					compatible = "syscon", "simple-mfd";
+					reg = <0x010000 0x1000>;
+
+					led@08.0 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x01>;
+						label = "vexpress:0";
+						linux,default-trigger = "heartbeat";
+						default-state = "on";
+					};
+					led@08.1 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x02>;
+						label = "vexpress:1";
+						linux,default-trigger = "mmc0";
+						default-state = "off";
+					};
+					led@08.2 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x04>;
+						label = "vexpress:2";
+						linux,default-trigger = "cpu0";
+						default-state = "off";
+					};
+					led@08.3 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x08>;
+						label = "vexpress:3";
+						linux,default-trigger = "cpu1";
+						default-state = "off";
+					};
+					led@08.4 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x10>;
+						label = "vexpress:4";
+						linux,default-trigger = "cpu2";
+						default-state = "off";
+					};
+					led@08.5 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x20>;
+						label = "vexpress:5";
+						linux,default-trigger = "cpu3";
+						default-state = "off";
+					};
+					led@08.6 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x40>;
+						label = "vexpress:6";
+						default-state = "off";
+					};
+					led@08.7 {
+						compatible = "register-bit-led";
+						offset = <0x08>;
+						mask = <0x80>;
+						label = "vexpress:7";
+						default-state = "off";
+					};
+				};
+
 				mmci@050000 {
 					compatible = "arm,pl180", "arm,primecell";
 					reg = <0x050000 0x1000>;

arch/arm64/configs/defconfig

@@ -138,6 +138,12 @@ CONFIG_MMC_ARMMMCI=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_PLTFM=y
 CONFIG_MMC_SPI=y
+CONFIG_NEW_LEDS=y
+CONFIG_LEDS_CLASS=y
+CONFIG_LEDS_SYSCON=y
+CONFIG_LEDS_TRIGGERS=y
+CONFIG_LEDS_TRIGGER_HEARTBEAT=y
+CONFIG_LEDS_TRIGGER_CPU=y
 CONFIG_RTC_CLASS=y
 CONFIG_RTC_DRV_EFI=y
 CONFIG_RTC_DRV_XGENE=y

drivers/leds/leds-syscon.c

@@ -20,6 +20,7 @@
  * MA 02111-1307 USA
  */
 #include <linux/io.h>
+#include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
@@ -66,102 +67,101 @@ static void syscon_led_set(struct led_classdev *led_cdev,
 		dev_err(sled->cdev.dev, "error updating LED status\n");
 }
 
-static int __init syscon_leds_spawn(struct device_node *np,
+static int syscon_led_probe(struct platform_device *pdev)
-				    struct device *dev,
-				    struct regmap *map)
 {
-	struct device_node *child;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct device *parent;
+	struct regmap *map;
+	struct syscon_led *sled;
+	const char *state;
 	int ret;
 
-	for_each_available_child_of_node(np, child) {
+	parent = dev->parent;
-		struct syscon_led *sled;
+	if (!parent) {
-		const char *state;
+		dev_err(dev, "no parent for syscon LED\n");
-
+		return -ENODEV;
-		/* Only check for register-bit-leds */
-		if (of_property_match_string(child, "compatible",
-					     "register-bit-led") < 0)
-			continue;
-
-		sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
-		if (!sled)
-			return -ENOMEM;
-
-		sled->map = map;
-
-		if (of_property_read_u32(child, "offset", &sled->offset))
-			return -EINVAL;
-		if (of_property_read_u32(child, "mask", &sled->mask))
-			return -EINVAL;
-		sled->cdev.name =
-			of_get_property(child, "label", NULL) ? : child->name;
-		sled->cdev.default_trigger =
-			of_get_property(child, "linux,default-trigger", NULL);
-
-		state = of_get_property(child, "default-state", NULL);
-		if (state) {
-			if (!strcmp(state, "keep")) {
-				u32 val;
-
-				ret = regmap_read(map, sled->offset, &val);
-				if (ret < 0)
-					return ret;
-				sled->state = !!(val & sled->mask);
-			} else if (!strcmp(state, "on")) {
-				sled->state = true;
-				ret = regmap_update_bits(map, sled->offset,
-							 sled->mask,
-							 sled->mask);
-				if (ret < 0)
-					return ret;
-			} else {
-				sled->state = false;
-				ret = regmap_update_bits(map, sled->offset,
-							 sled->mask, 0);
-				if (ret < 0)
-					return ret;
-			}
-		}
-		sled->cdev.brightness_set = syscon_led_set;
-
-		ret = led_classdev_register(dev, &sled->cdev);
-		if (ret < 0)
-			return ret;
-
-		dev_info(dev, "registered LED %s\n", sled->cdev.name);
 	}
+	map = syscon_node_to_regmap(parent->of_node);
+	if (!map) {
+		dev_err(dev, "no regmap for syscon LED parent\n");
+		return -ENODEV;
+	}
+
+	sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
+	if (!sled)
+		return -ENOMEM;
+
+	sled->map = map;
+
+	if (of_property_read_u32(np, "offset", &sled->offset))
+		return -EINVAL;
+	if (of_property_read_u32(np, "mask", &sled->mask))
+		return -EINVAL;
+	sled->cdev.name =
+		of_get_property(np, "label", NULL) ? : np->name;
+	sled->cdev.default_trigger =
+		of_get_property(np, "linux,default-trigger", NULL);
+
+	state = of_get_property(np, "default-state", NULL);
+	if (state) {
+		if (!strcmp(state, "keep")) {
+			u32 val;
+
+			ret = regmap_read(map, sled->offset, &val);
+			if (ret < 0)
+				return ret;
+			sled->state = !!(val & sled->mask);
+		} else if (!strcmp(state, "on")) {
+			sled->state = true;
+			ret = regmap_update_bits(map, sled->offset,
+						 sled->mask,
+						 sled->mask);
+			if (ret < 0)
+				return ret;
+		} else {
+			sled->state = false;
+			ret = regmap_update_bits(map, sled->offset,
+						 sled->mask, 0);
+			if (ret < 0)
+				return ret;
+		}
+	}
+	sled->cdev.brightness_set = syscon_led_set;
+
+	ret = led_classdev_register(dev, &sled->cdev);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, sled);
+	dev_info(dev, "registered LED %s\n", sled->cdev.name);
+
 	return 0;
 }
 
-static int __init syscon_leds_init(void)
+static int syscon_led_remove(struct platform_device *pdev)
 {
-	struct device_node *np;
+	struct syscon_led *sled = platform_get_drvdata(pdev);
-
-	for_each_of_allnodes(np) {
-		struct platform_device *pdev;
-		struct regmap *map;
-		int ret;
-
-		if (!of_device_is_compatible(np, "syscon"))
-			continue;
-
-		map = syscon_node_to_regmap(np);
-		if (IS_ERR(map)) {
-			pr_err("error getting regmap for syscon LEDs\n");
-			continue;
-		}
-
-		/*
-		 * If the map is there, the device should be there, we allocate
-		 * memory on the syscon device's behalf here.
-		 */
-		pdev = of_find_device_by_node(np);
-		if (!pdev)
-			return -ENODEV;
-		ret = syscon_leds_spawn(np, &pdev->dev, map);
-		if (ret)
-			dev_err(&pdev->dev, "could not spawn syscon LEDs\n");
-	}
 
+	led_classdev_unregister(&sled->cdev);
+	/* Turn it off */
+	regmap_update_bits(sled->map, sled->offset, sled->mask, 0);
 	return 0;
 }
-device_initcall(syscon_leds_init);
+
+static const struct of_device_id of_syscon_leds_match[] = {
+	{ .compatible = "register-bit-led", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, of_syscon_leds_match);
+
+static struct platform_driver syscon_led_driver = {
+	.probe		= syscon_led_probe,
+	.remove		= syscon_led_remove,
+	.driver		= {
+		.name	= "leds-syscon",
+		.of_match_table = of_syscon_leds_match,
+	},
+};
+module_platform_driver(syscon_led_driver);

drivers/of/platform.c

@@ -25,6 +25,7 @@
 
 const struct of_device_id of_default_bus_match_table[] = {
 	{ .compatible = "simple-bus", },
+	{ .compatible = "simple-mfd", },
 #ifdef CONFIG_ARM_AMBA
 	{ .compatible = "arm,amba-bus", },
 #endif /* CONFIG_ARM_AMBA */