dm: led: add BCM6328 led driver

This driver is a simplified version of linux/drivers/leds/leds-bcm6328.c,
simplified to remove HW leds and blink fallbacks.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

doc/device-tree-bindings/leds/leds-bcm6328.txt

@@ -0,0 +1,106 @@
+LEDs connected to Broadcom BCM6328 controller
+
+This controller is present on BCM6318, BCM6328, BCM6362 and BCM63268.
+In these SoCs it's possible to control LEDs both as GPIOs or by hardware.
+However, on some devices there are Serial LEDs (LEDs connected to a 74x164
+controller), which can either be controlled by software (exporting the 74x164
+as spi-gpio. See Documentation/devicetree/bindings/gpio/gpio-74x164.txt), or
+by hardware using this driver.
+Some of these Serial LEDs are hardware controlled (e.g. ethernet LEDs) and
+exporting the 74x164 as spi-gpio prevents those LEDs to be hardware
+controlled, so the only chance to keep them working is by using this driver.
+
+Required properties:
+  - compatible : should be "brcm,bcm6328-leds".
+  - #address-cells : must be 1.
+  - #size-cells : must be 0.
+  - reg : BCM6328 LED controller address and size.
+
+Optional properties:
+  - brcm,serial-leds : Boolean, enables Serial LEDs.
+    Default : false
+  - brcm,serial-mux : Boolean, enables Serial LEDs multiplexing.
+    Default : false
+  - brcm,serial-clk-low : Boolean, makes clock signal active low.
+    Default : false
+  - brcm,serial-dat-low : Boolean, makes data signal active low.
+    Default : false
+  - brcm,serial-shift-inv : Boolean, inverts Serial LEDs shift direction.
+    Default : false
+
+Each LED is represented as a sub-node of the brcm,bcm6328-leds device.
+
+LED sub-node required properties:
+  - reg : LED pin number (only LEDs 0 to 23 are valid).
+
+LED sub-node optional properties:
+  - label : see Documentation/devicetree/bindings/leds/common.txt
+  - active-low : Boolean, makes LED active low.
+    Default : false
+
+Examples:
+Scenario 1 : BCM6328 with 4 GPIO LEDs
+	leds0: led-controller@10000800 {
+		compatible = "brcm,bcm6328-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x10000800 0x24>;
+
+		alarm_red@2 {
+			reg = <2>;
+			active-low;
+			label = "red:alarm";
+		};
+		inet_green@3 {
+			reg = <3>;
+			active-low;
+			label = "green:inet";
+		};
+		power_green@4 {
+			reg = <4>;
+			active-low;
+			label = "green:power";
+		};
+	};
+
+Scenario 2 : BCM63268 with Serial LEDs
+	leds0: led-controller@10001900 {
+		compatible = "brcm,bcm6328-leds";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x10001900 0x24>;
+		brcm,serial-leds;
+		brcm,serial-dat-low;
+		brcm,serial-shift-inv;
+
+		inet_red@2 {
+			reg = <2>;
+			active-low;
+			label = "red:inet";
+		};
+		dsl_green@3 {
+			reg = <3>;
+			active-low;
+			label = "green:dsl";
+		};
+		usb_green@4 {
+			reg = <4>;
+			active-low;
+			label = "green:usb";
+		};
+		wps_green@7 {
+			reg = <7>;
+			active-low;
+			label = "green:wps";
+		};
+		inet_green@8 {
+			reg = <8>;
+			active-low;
+			label = "green:inet";
+		};
+		power_green@20 {
+			reg = <20>;
+			active-low;
+			label = "green:power";
+		};
+	};

drivers/led/Kconfig

@@ -9,6 +9,17 @@ config LED
 	  can provide access to board-specific LEDs. Use of the device tree
 	  for configuration is encouraged.
 
+config LED_BCM6328
+	bool "LED Support for BCM6328"
+	depends on LED && ARCH_BMIPS
+	help
+	  This option enables support for LEDs connected to the BCM6328
+	  LED HW controller accessed via MMIO registers.
+	  HW blinking is supported and up to 24 LEDs can be controlled.
+	  All LEDs can blink at the same time but the delay is shared, which
+	  means that if one LED is set to blink at 100ms and then a different
+	  LED is set to blink at 200ms, both will blink at 200ms.
+
 config LED_BLINK
 	bool "Support LED blinking"
 	depends on LED

drivers/led/Makefile

@@ -6,4 +6,5 @@
 #
 
 obj-y += led-uclass.o
+obj-$(CONFIG_LED_BCM6328) += led_bcm6328.o
 obj-$(CONFIG_$(SPL_)LED_GPIO) += led_gpio.o

drivers/led/led_bcm6328.c

@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <led.h>
+#include <asm/io.h>
+#include <dm/lists.h>
+
+#define LEDS_MAX			24
+
+/* LED Init register */
+#define LED_INIT_REG			0x00
+#define LED_INIT_FASTINTV_MS		20
+#define LED_INIT_FASTINTV_SHIFT		6
+#define LED_INIT_FASTINTV_MASK		(0x3f << LED_INIT_FASTINTV_SHIFT)
+#define LED_INIT_SLEDEN_SHIFT		12
+#define LED_INIT_SLEDEN_MASK		(1 << LED_INIT_SLEDEN_SHIFT)
+#define LED_INIT_SLEDMUX_SHIFT		13
+#define LED_INIT_SLEDMUX_MASK		(1 << LED_INIT_SLEDMUX_SHIFT)
+#define LED_INIT_SLEDCLKNPOL_SHIFT	14
+#define LED_INIT_SLEDCLKNPOL_MASK	(1 << LED_INIT_SLEDCLKNPOL_SHIFT)
+#define LED_INIT_SLEDDATAPPOL_SHIFT	15
+#define LED_INIT_SLEDDATANPOL_MASK	(1 << LED_INIT_SLEDDATAPPOL_SHIFT)
+#define LED_INIT_SLEDSHIFTDIR_SHIFT	16
+#define LED_INIT_SLEDSHIFTDIR_MASK	(1 << LED_INIT_SLEDSHIFTDIR_SHIFT)
+
+/* LED Mode registers */
+#define LED_MODE_REG_HI			0x04
+#define LED_MODE_REG_LO			0x08
+#define LED_MODE_ON			0
+#define LED_MODE_FAST			1
+#define LED_MODE_BLINK			2
+#define LED_MODE_OFF			3
+#define LED_MODE_MASK			0x3
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct bcm6328_led_priv {
+	void __iomem *regs;
+	void __iomem *mode;
+	uint8_t shift;
+	bool active_low;
+};
+
+static unsigned long bcm6328_led_get_mode(struct bcm6328_led_priv *priv)
+{
+	return ((readl_be(priv->mode) >> priv->shift) & LED_MODE_MASK);
+}
+
+static int bcm6328_led_set_mode(struct bcm6328_led_priv *priv, uint8_t mode)
+{
+	clrsetbits_be32(priv->mode, (LED_MODE_MASK << priv->shift),
+			(mode << priv->shift));
+
+	return 0;
+}
+
+static enum led_state_t bcm6328_led_get_state(struct udevice *dev)
+{
+	struct bcm6328_led_priv *priv = dev_get_priv(dev);
+	enum led_state_t state = LEDST_OFF;
+
+	switch (bcm6328_led_get_mode(priv)) {
+#ifdef CONFIG_LED_BLINK
+	case LED_MODE_BLINK:
+	case LED_MODE_FAST:
+		state = LEDST_BLINK;
+		break;
+#endif
+	case LED_MODE_OFF:
+		state = (priv->active_low ? LEDST_ON : LEDST_OFF);
+		break;
+	case LED_MODE_ON:
+		state = (priv->active_low ? LEDST_OFF : LEDST_ON);
+		break;
+	}
+
+	return state;
+}
+
+static int bcm6328_led_set_state(struct udevice *dev, enum led_state_t state)
+{
+	struct bcm6328_led_priv *priv = dev_get_priv(dev);
+	unsigned long mode;
+
+	switch (state) {
+#ifdef CONFIG_LED_BLINK
+	case LEDST_BLINK:
+		mode = LED_MODE_BLINK;
+		break;
+#endif
+	case LEDST_OFF:
+		mode = (priv->active_low ? LED_MODE_ON : LED_MODE_OFF);
+		break;
+	case LEDST_ON:
+		mode = (priv->active_low ? LED_MODE_OFF : LED_MODE_ON);
+		break;
+	case LEDST_TOGGLE:
+		if (bcm6328_led_get_state(dev) == LEDST_OFF)
+			return bcm6328_led_set_state(dev, LEDST_ON);
+		else
+			return bcm6328_led_set_state(dev, LEDST_OFF);
+		break;
+	default:
+		return -ENOSYS;
+	}
+
+	return bcm6328_led_set_mode(priv, mode);
+}
+
+#ifdef CONFIG_LED_BLINK
+static unsigned long bcm6328_blink_delay(int delay)
+{
+	unsigned long bcm6328_delay = delay;
+
+	bcm6328_delay += (LED_INIT_FASTINTV_MS / 2);
+	bcm6328_delay /= LED_INIT_FASTINTV_MS;
+	bcm6328_delay <<= LED_INIT_FASTINTV_SHIFT;
+
+	if (bcm6328_delay > LED_INIT_FASTINTV_MASK)
+		return LED_INIT_FASTINTV_MASK;
+	else
+		return bcm6328_delay;
+}
+
+static int bcm6328_led_set_period(struct udevice *dev, int period_ms)
+{
+	struct bcm6328_led_priv *priv = dev_get_priv(dev);
+
+	clrsetbits_be32(priv->regs + LED_INIT_REG, LED_INIT_FASTINTV_MASK,
+			bcm6328_blink_delay(period_ms));
+
+	return 0;
+}
+#endif
+
+static const struct led_ops bcm6328_led_ops = {
+	.get_state = bcm6328_led_get_state,
+	.set_state = bcm6328_led_set_state,
+#ifdef CONFIG_LED_BLINK
+	.set_period = bcm6328_led_set_period,
+#endif
+};
+
+static int bcm6328_led_probe(struct udevice *dev)
+{
+	struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
+	fdt_addr_t addr;
+	fdt_size_t size;
+
+	/* Top-level LED node */
+	if (!uc_plat->label) {
+		void __iomem *regs;
+		u32 set_bits = 0;
+
+		addr = dev_get_addr_size_index(dev, 0, &size);
+		if (addr == FDT_ADDR_T_NONE)
+			return -EINVAL;
+
+		regs = ioremap(addr, size);
+
+		if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
+				    "brcm,serial-leds"))
+			set_bits |= LED_INIT_SLEDEN_MASK;
+		if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
+				    "brcm,serial-mux"))
+			set_bits |= LED_INIT_SLEDMUX_MASK;
+		if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
+				    "brcm,serial-clk-low"))
+			set_bits |= LED_INIT_SLEDCLKNPOL_MASK;
+		if (!fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
+				     "brcm,serial-dat-low"))
+			set_bits |= LED_INIT_SLEDDATANPOL_MASK;
+		if (!fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
+				     "brcm,serial-shift-inv"))
+			set_bits |= LED_INIT_SLEDSHIFTDIR_MASK;
+
+		clrsetbits_be32(regs + LED_INIT_REG, ~0, set_bits);
+	} else {
+		struct bcm6328_led_priv *priv = dev_get_priv(dev);
+		unsigned int pin;
+
+		addr = dev_get_addr_size_index(dev_get_parent(dev), 0, &size);
+		if (addr == FDT_ADDR_T_NONE)
+			return -EINVAL;
+
+		pin = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev), "reg",
+				      LEDS_MAX);
+		if (pin >= LEDS_MAX)
+			return -EINVAL;
+
+		priv->regs = ioremap(addr, size);
+		if (pin < 8) {
+			/* LEDs 0-7 (bits 47:32) */
+			priv->mode = priv->regs + LED_MODE_REG_HI;
+			priv->shift = (pin << 1);
+		} else {
+			/* LEDs 8-23 (bits 31:0) */
+			priv->mode = priv->regs + LED_MODE_REG_LO;
+			priv->shift = ((pin - 8) << 1);
+		}
+
+		if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
+				    "active-low"))
+			priv->active_low = true;
+	}
+
+	return 0;
+}
+
+static int bcm6328_led_bind(struct udevice *parent)
+{
+	const void *blob = gd->fdt_blob;
+	int node;
+
+	for (node = fdt_first_subnode(blob, dev_of_offset(parent));
+	     node > 0;
+	     node = fdt_next_subnode(blob, node)) {
+		struct led_uc_plat *uc_plat;
+		struct udevice *dev;
+		const char *label;
+		int ret;
+
+		label = fdt_getprop(blob, node, "label", NULL);
+		if (!label) {
+			debug("%s: node %s has no label\n", __func__,
+			      fdt_get_name(blob, node, NULL));
+			return -EINVAL;
+		}
+
+		ret = device_bind_driver_to_node(parent, "bcm6328-led",
+						 fdt_get_name(blob, node, NULL),
+						 node, &dev);
+		if (ret)
+			return ret;
+
+		uc_plat = dev_get_uclass_platdata(dev);
+		uc_plat->label = label;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id bcm6328_led_ids[] = {
+	{ .compatible = "brcm,bcm6328-leds" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(bcm6328_led) = {
+	.name = "bcm6328-led",
+	.id = UCLASS_LED,
+	.of_match = bcm6328_led_ids,
+	.ops = &bcm6328_led_ops,
+	.bind = bcm6328_led_bind,
+	.probe = bcm6328_led_probe,
+	.priv_auto_alloc_size = sizeof(struct bcm6328_led_priv),
+};