led: add initial support for bcm6858

The driver add the support of the led IP on bcm6858.
This led IP can drive up to 32 leds, and can handle
blinking.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

1 files changed, 250 insertions, 0 deletions

diff --git a/drivers/led/led_bcm6858.c b/drivers/led/led_bcm6858.c
new file mode 100644
index 0000000000..27a76fcaf0
--- /dev/null
+++ b/drivers/led/led_bcm6858.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Philippe Reynes <philippe.reynes@softathome.com>
+ *
+ * based on:
+ * drivers/led/led_bcm6328.c
+ * drivers/led/led_bcm6358.c
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <led.h>
+#include <asm/io.h>
+#include <dm/lists.h>
+
+#define LEDS_MAX		32
+#define LEDS_WAIT		100
+
+/* LED Mode register */
+#define LED_MODE_REG		0x0
+#define LED_MODE_OFF		0
+#define LED_MODE_ON		1
+#define LED_MODE_MASK		1
+
+/* LED Controller Global settings register */
+#define LED_CTRL_REG			0x00
+#define LED_CTRL_MASK			0x1f
+#define LED_CTRL_LED_TEST_MODE		BIT(0)
+#define LED_CTRL_SERIAL_LED_DATA_PPOL	BIT(1)
+#define LED_CTRL_SERIAL_LED_CLK_POL	BIT(2)
+#define LED_CTRL_SERIAL_LED_EN_POL	BIT(3)
+#define LED_CTRL_SERIAL_LED_MSB_FIRST	BIT(4)
+
+/* LED Controller IP LED source select register */
+#define LED_HW_LED_EN_REG		0x08
+/* LED Flash control register0 */
+#define LED_FLASH_RATE_CONTROL_REG0	0x10
+/* Soft LED input register */
+#define LED_SW_LED_IP_REG		0xb8
+/* Soft LED input polarity register */
+#define LED_SW_LED_IP_PPOL_REG		0xbc
+
+struct bcm6858_led_priv {
+	void __iomem *regs;
+	u8 pin;
+};
+
+#ifdef CONFIG_LED_BLINK
+/*
+ * The value for flash rate are:
+ * 0 : no blinking
+ * 1 : rate is 25 Hz => 40 ms (period)
+ * 2 : rate is 12.5 Hz => 80 ms (period)
+ * 3 : rate is 6.25 Hz => 160 ms (period)
+ * 4 : rate is 3.125 Hz => 320 ms (period)
+ * 5 : rate is 1.5625 Hz => 640 ms (period)
+ * 6 : rate is 0.7815 Hz => 1280 ms (period)
+ * 7 : rate is 0.390625 Hz => 2560 ms (period)
+ */
+static const int bcm6858_flash_rate[8] = {
+	0, 40, 80, 160, 320, 640, 1280, 2560
+};
+
+static u32 bcm6858_flash_rate_value(int period_ms)
+{
+	unsigned long value = 7;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bcm6858_flash_rate); i++) {
+		if (period_ms <= bcm6858_flash_rate[i]) {
+			value = i;
+			break;
+		}
+	}
+
+	return value;
+}
+
+static int bcm6858_led_set_period(struct udevice *dev, int period_ms)
+{
+	struct bcm6858_led_priv *priv = dev_get_priv(dev);
+	u32 offset, shift, mask, value;
+
+	offset = (priv->pin / 8) * 4;
+	shift  = (priv->pin % 8) * 4;
+	mask   = 0x7 << shift;
+	value  = bcm6858_flash_rate_value(period_ms) << shift;
+
+	clrbits_32(priv->regs + LED_FLASH_RATE_CONTROL_REG0 + offset, mask);
+	setbits_32(priv->regs + LED_FLASH_RATE_CONTROL_REG0 + offset, value);
+
+	return 0;
+}
+#endif
+
+static enum led_state_t bcm6858_led_get_state(struct udevice *dev)
+{
+	struct bcm6858_led_priv *priv = dev_get_priv(dev);
+	enum led_state_t state = LEDST_OFF;
+	u32 sw_led_ip;
+
+	sw_led_ip = readl(priv->regs + LED_SW_LED_IP_REG);
+	if (sw_led_ip & (1 << priv->pin))
+		state = LEDST_ON;
+
+	return state;
+}
+
+static int bcm6858_led_set_state(struct udevice *dev, enum led_state_t state)
+{
+	struct bcm6858_led_priv *priv = dev_get_priv(dev);
+
+	switch (state) {
+	case LEDST_OFF:
+		clrbits_32(priv->regs + LED_SW_LED_IP_REG, (1 << priv->pin));
+#ifdef CONFIG_LED_BLINK
+		bcm6858_led_set_period(dev, 0);
+#endif
+		break;
+	case LEDST_ON:
+		setbits_32(priv->regs + LED_SW_LED_IP_REG, (1 << priv->pin));
+#ifdef CONFIG_LED_BLINK
+		bcm6858_led_set_period(dev, 0);
+#endif
+		break;
+	case LEDST_TOGGLE:
+		if (bcm6858_led_get_state(dev) == LEDST_OFF)
+			return bcm6858_led_set_state(dev, LEDST_ON);
+		else
+			return bcm6858_led_set_state(dev, LEDST_OFF);
+		break;
+#ifdef CONFIG_LED_BLINK
+	case LEDST_BLINK:
+		setbits_32(priv->regs + LED_SW_LED_IP_REG, (1 << priv->pin));
+		break;
+#endif
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct led_ops bcm6858_led_ops = {
+	.get_state = bcm6858_led_get_state,
+	.set_state = bcm6858_led_set_state,
+#ifdef CONFIG_LED_BLINK
+	.set_period = bcm6858_led_set_period,
+#endif
+};
+
+static int bcm6858_led_probe(struct udevice *dev)
+{
+	struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
+
+	/* Top-level LED node */
+	if (!uc_plat->label) {
+		void __iomem *regs;
+		u32 set_bits = 0;
+
+		regs = dev_remap_addr(dev);
+		if (!regs)
+			return -EINVAL;
+
+		if (dev_read_bool(dev, "brcm,serial-led-msb-first"))
+			set_bits |= LED_CTRL_SERIAL_LED_MSB_FIRST;
+		if (dev_read_bool(dev, "brcm,serial-led-en-pol"))
+			set_bits |= LED_CTRL_SERIAL_LED_EN_POL;
+		if (dev_read_bool(dev, "brcm,serial-led-clk-pol"))
+			set_bits |= LED_CTRL_SERIAL_LED_CLK_POL;
+		if (dev_read_bool(dev, "brcm,serial-led-data-ppol"))
+			set_bits |= LED_CTRL_SERIAL_LED_DATA_PPOL;
+		if (dev_read_bool(dev, "brcm,led-test-mode"))
+			set_bits |= LED_CTRL_LED_TEST_MODE;
+
+		clrsetbits_32(regs + LED_CTRL_REG, ~0, set_bits);
+	} else {
+		struct bcm6858_led_priv *priv = dev_get_priv(dev);
+		void __iomem *regs;
+		unsigned int pin;
+
+		regs = dev_remap_addr(dev_get_parent(dev));
+		if (!regs)
+			return -EINVAL;
+
+		pin = dev_read_u32_default(dev, "reg", LEDS_MAX);
+		if (pin >= LEDS_MAX)
+			return -EINVAL;
+
+		priv->regs = regs;
+		priv->pin = pin;
+
+		/* this led is managed by software */
+		clrbits_32(regs + LED_HW_LED_EN_REG, 1 << pin);
+
+		/* configure the polarity */
+		if (dev_read_bool(dev, "active-low"))
+			clrbits_32(regs + LED_SW_LED_IP_PPOL_REG, 1 << pin);
+		else
+			setbits_32(regs + LED_SW_LED_IP_PPOL_REG, 1 << pin);
+	}
+
+	return 0;
+}
+
+static int bcm6858_led_bind(struct udevice *parent)
+{
+	ofnode node;
+
+	dev_for_each_subnode(node, parent) {
+		struct led_uc_plat *uc_plat;
+		struct udevice *dev;
+		const char *label;
+		int ret;
+
+		label = ofnode_read_string(node, "label");
+		if (!label) {
+			debug("%s: node %s has no label\n", __func__,
+			      ofnode_get_name(node));
+			return -EINVAL;
+		}
+
+		ret = device_bind_driver_to_node(parent, "bcm6858-led",
+						 ofnode_get_name(node),
+						 node, &dev);
+		if (ret)
+			return ret;
+
+		uc_plat = dev_get_uclass_platdata(dev);
+		uc_plat->label = label;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id bcm6858_led_ids[] = {
+	{ .compatible = "brcm,bcm6858-leds" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(bcm6858_led) = {
+	.name = "bcm6858-led",
+	.id = UCLASS_LED,
+	.of_match = bcm6858_led_ids,
+	.bind = bcm6858_led_bind,
+	.probe = bcm6858_led_probe,
+	.priv_auto_alloc_size = sizeof(struct bcm6858_led_priv),
+	.ops = &bcm6858_led_ops,
+};