[PATCH v2 1/2] dt-bindings: leds: Add Allwinner R329/D1 LED controller

[PATCH v2 1/2] dt-bindings: leds: Add Allwinner R329/D1 LED controller

[Samuel Holland]

The Allwinner R329 and D1 SoCs contain an LED controller designed to
drive a series of RGB LED pixels. It supports PIO and DMA transfers, and
has configurable timing and pixel format.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

Changes from v1:
 - Fixed typo leading to duplicate t1h-ns property
 - Removed "items" layer in definition of dmas/dma-names
 - Replaced uint32 type reference with maxItems in timing properties

 .../leds/allwinner,sun50i-r329-ledc.yaml      | 140 ++++++++++++++++++
 1 file changed, 140 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml

diff --git a/Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml b/Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml
new file mode 100644
index 000000000000..d70cb2393a2e
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml
@@ -0,0 +1,140 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/allwinner,sun50i-r329-ledc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner R329 LED Controller Bindings
+
+maintainers:
+  - Samuel Holland <samuel@sholland.org>
+
+description:
+  The LED controller found in Allwinner sunxi SoCs uses a one-wire serial
+  interface to drive up to 1024 RGB LEDs.
+
+properties:
+  compatible:
+    oneOf:
+      - const: allwinner,sun50i-r329-ledc
+      - items:
+          - enum:
+              - allwinner,sun20i-d1-ledc
+          - const: allwinner,sun50i-r329-ledc
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  clocks:
+    items:
+      - description: Bus clock
+      - description: Module clock
+
+  clock-names:
+    items:
+      - const: bus
+      - const: mod
+
+  resets:
+    maxItems: 1
+
+  dmas:
+    maxItems: 1
+    description: TX DMA channel
+
+  dma-names:
+    const: tx
+
+  interrupts:
+    maxItems: 1
+
+  vled-supply:
+    description: Regulator supplying power to external LEDs
+
+  format:
+    description: Pixel format (subpixel transmission order), default is "grb"
+    enum:
+      - "bgr"
+      - "brg"
+      - "gbr"
+      - "grb"
+      - "rbg"
+      - "rgb"
+
+  t0h-ns:
+    maxItems: 1
+    description: Length of high pulse when transmitting a "0" bit
+
+  t0l-ns:
+    maxItems: 1
+    description: Length of low pulse when transmitting a "0" bit
+
+  t1h-ns:
+    maxItems: 1
+    description: Length of high pulse when transmitting a "1" bit
+
+  t1l-ns:
+    maxItems: 1
+    description: Length of low pulse when transmitting a "1" bit
+
+  treset-ns:
+    maxItems: 1
+    description: Minimum delay between transmission frames
+
+patternProperties:
+  "^multi-led@[0-9a-f]+$":
+    type: object
+    $ref: leds-class-multicolor.yaml#
+    properties:
+      reg:
+        minimum: 0
+        maximum: 1023
+        description: Index of the LED in the series (must be contiguous)
+
+    required:
+      - reg
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - dmas
+  - dma-names
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/leds/common.h>
+
+    ledc: led-controller@2008000 {
+      compatible = "allwinner,sun20i-d1-ledc",
+                   "allwinner,sun50i-r329-ledc";
+      reg = <0x2008000 0x400>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+      clocks = <&ccu 12>, <&ccu 34>;
+      clock-names = "bus", "mod";
+      resets = <&ccu 12>;
+      dmas = <&dma 42>;
+      dma-names = "tx";
+      interrupts = <36 IRQ_TYPE_LEVEL_HIGH>;
+
+      multi-led@0 {
+        reg = <0x0>;
+        color = <LED_COLOR_ID_RGB>;
+        function = LED_FUNCTION_INDICATOR;
+      };
+    };
+
+...
-- 
2.32.0

[PATCH v2 2/2] leds: sunxi: New driver for the R329/D1 LED controller

[Samuel Holland]

Some Allwinner sunxi SoCs, starting with the R329, contain an LED
controller designed to drive RGB LED pixels. Add a driver for it using
the multicolor LED framework, and with LEDs defined in the device tree.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

Changes from v1:
 - Renamed from sunxi-ledc to sun50i-r329-ledc
 - Added missing "static" to functions/globals as reported by 0day bot

 drivers/leds/Kconfig            |   8 +
 drivers/leds/Makefile           |   1 +
 drivers/leds/leds-sun50i-r329.c | 566 ++++++++++++++++++++++++++++++++
 3 files changed, 575 insertions(+)
 create mode 100644 drivers/leds/leds-sun50i-r329.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index ed800f5da7d8..d5c1396788fe 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -297,6 +297,14 @@ config LEDS_SUNFIRE
 	  This option enables support for the Left, Middle, and Right
 	  LEDs on the I/O and CPU boards of SunFire UltraSPARC servers.
 
+config LEDS_SUN50I_R329
+	tristate "LED support for Allwinner R329 LED controller"
+	depends on LEDS_CLASS
+	depends on ARCH_SUNXI || COMPILE_TEST
+	help
+	  This option enables support for the RGB LED controller
+	  provided in some Allwinner sunxi SoCs, like the R329.
+
 config LEDS_IPAQ_MICRO
 	tristate "LED Support for the Compaq iPAQ h3xxx"
 	depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index c636ec069612..506b2617099d 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_PWM)			+= leds-pwm.o
 obj-$(CONFIG_LEDS_REGULATOR)		+= leds-regulator.o
 obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o
 obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o
+obj-$(CONFIG_LEDS_SUN50I_R329)		+= leds-sun50i-r329.o
 obj-$(CONFIG_LEDS_SUNFIRE)		+= leds-sunfire.o
 obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o
 obj-$(CONFIG_LEDS_TCA6507)		+= leds-tca6507.o
diff --git a/drivers/leds/leds-sun50i-r329.c b/drivers/leds/leds-sun50i-r329.c
new file mode 100644
index 000000000000..3dfa1840a745
--- /dev/null
+++ b/drivers/leds/leds-sun50i-r329.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2021 Samuel Holland <samuel@sholland.org>
+//
+// Partly based on drivers/leds/leds-turris-omnia.c, which is:
+//     Copyright (c) 2020 by Marek Behún <kabel@kernel.org>
+//
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/spinlock.h>
+
+#define LEDC_CTRL_REG			0x0000
+#define LEDC_CTRL_REG_DATA_LENGTH		(0x1fff << 16)
+#define LEDC_CTRL_REG_RGB_MODE			(0x7 << 6)
+#define LEDC_CTRL_REG_LEDC_EN			BIT(0)
+#define LEDC_T01_TIMING_CTRL_REG	0x0004
+#define LEDC_T01_TIMING_CTRL_REG_T1H		(0x3f << 21)
+#define LEDC_T01_TIMING_CTRL_REG_T1L		(0x1f << 16)
+#define LEDC_T01_TIMING_CTRL_REG_T0H		(0x1f << 6)
+#define LEDC_T01_TIMING_CTRL_REG_T0L		(0x3f << 0)
+#define LEDC_RESET_TIMING_CTRL_REG	0x000c
+#define LEDC_RESET_TIMING_CTRL_REG_LED_NUM	(0x3ff << 0)
+#define LEDC_DATA_REG			0x0014
+#define LEDC_DMA_CTRL_REG		0x0018
+#define LEDC_DMA_CTRL_REG_FIFO_TRIG_LEVEL	(0x1f << 0)
+#define LEDC_INT_CTRL_REG		0x001c
+#define LEDC_INT_CTRL_REG_GLOBAL_INT_EN		BIT(5)
+#define LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN	BIT(1)
+#define LEDC_INT_CTRL_REG_TRANS_FINISH_INT_EN	BIT(0)
+#define LEDC_INT_STS_REG		0x0020
+#define LEDC_INT_STS_REG_FIFO_CPUREQ_INT	BIT(1)
+#define LEDC_INT_STS_REG_TRANS_FINISH_INT	BIT(0)
+
+#define LEDC_FIFO_DEPTH			32
+#define LEDC_MAX_LEDS			1024
+
+#define LEDS_TO_BYTES(n)		((n) * sizeof(u32))
+
+struct sun50i_r329_ledc_led {
+	struct led_classdev_mc mc_cdev;
+	struct mc_subled subled_info[3];
+};
+#define to_ledc_led(mc) container_of(mc, struct sun50i_r329_ledc_led, mc_cdev)
+
+struct sun50i_r329_ledc_timing {
+	u32 t0h_ns;
+	u32 t0l_ns;
+	u32 t1h_ns;
+	u32 t1l_ns;
+	u32 treset_ns;
+};
+
+struct sun50i_r329_ledc {
+	struct device *dev;
+	void __iomem *base;
+	struct clk *bus_clk;
+	struct clk *mod_clk;
+	struct reset_control *reset;
+	struct regulator *vled;
+
+	u32 *buffer;
+	struct dma_chan *dma_chan;
+	dma_addr_t dma_handle;
+	int pio_length;
+	int pio_offset;
+
+	spinlock_t lock;
+	int next_length;
+	bool xfer_active;
+
+	u32 format;
+	struct sun50i_r329_ledc_timing timing;
+
+	int num_leds;
+	struct sun50i_r329_ledc_led leds[];
+};
+
+static int sun50i_r329_ledc_dma_xfer(struct sun50i_r329_ledc *priv, int length)
+{
+	struct dma_async_tx_descriptor *desc;
+	dma_cookie_t cookie;
+
+	desc = dmaengine_prep_slave_single(priv->dma_chan, priv->dma_handle,
+					   LEDS_TO_BYTES(length),
+					   DMA_MEM_TO_DEV, 0);
+	if (!desc)
+		return -ENOMEM;
+
+	cookie = dmaengine_submit(desc);
+	if (dma_submit_error(cookie))
+		return -EIO;
+
+	dma_async_issue_pending(priv->dma_chan);
+
+	return 0;
+}
+
+static void sun50i_r329_ledc_pio_xfer(struct sun50i_r329_ledc *priv, int length)
+{
+	u32 burst, offset, val;
+
+	if (length) {
+		/* New transfer (FIFO is empty). */
+		offset = 0;
+		burst  = min(length, LEDC_FIFO_DEPTH);
+	} else {
+		/* Existing transfer (FIFO is half-full). */
+		length = priv->pio_length;
+		offset = priv->pio_offset;
+		burst  = min(length, LEDC_FIFO_DEPTH / 2);
+	}
+
+	writesl(priv->base + LEDC_DATA_REG, priv->buffer + offset, burst);
+
+	if (burst < length) {
+		priv->pio_length = length - burst;
+		priv->pio_offset = offset + burst;
+
+		if (!offset) {
+			val = readl(priv->base + LEDC_INT_CTRL_REG);
+			val |= LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN;
+			writel(val, priv->base + LEDC_INT_CTRL_REG);
+		}
+	} else {
+		/* Disable the request IRQ once all data is written. */
+		val = readl(priv->base + LEDC_INT_CTRL_REG);
+		val &= ~LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN;
+		writel(val, priv->base + LEDC_INT_CTRL_REG);
+	}
+}
+
+static void sun50i_r329_ledc_start_xfer(struct sun50i_r329_ledc *priv,
+					int length)
+{
+	u32 val;
+
+	dev_dbg(priv->dev, "Updating %d LEDs\n", length);
+
+	val = readl(priv->base + LEDC_CTRL_REG);
+	val &= ~LEDC_CTRL_REG_DATA_LENGTH;
+	val |= length << 16 | LEDC_CTRL_REG_LEDC_EN;
+	writel(val, priv->base + LEDC_CTRL_REG);
+
+	if (length > LEDC_FIFO_DEPTH) {
+		int ret = sun50i_r329_ledc_dma_xfer(priv, length);
+
+		if (!ret)
+			return;
+
+		dev_warn(priv->dev, "Failed to set up DMA: %d\n", ret);
+	}
+
+	sun50i_r329_ledc_pio_xfer(priv, length);
+}
+
+static irqreturn_t sun50i_r329_ledc_irq(int irq, void *dev_id)
+{
+	struct sun50i_r329_ledc *priv = dev_id;
+	u32 val;
+
+	val = readl(priv->base + LEDC_INT_STS_REG);
+
+	if (val & LEDC_INT_STS_REG_TRANS_FINISH_INT) {
+		int next_length;
+
+		/* Start the next transfer if needed. */
+		spin_lock(&priv->lock);
+		next_length = priv->next_length;
+		if (next_length)
+			priv->next_length = 0;
+		else
+			priv->xfer_active = false;
+		spin_unlock(&priv->lock);
+
+		if (next_length)
+			sun50i_r329_ledc_start_xfer(priv, next_length);
+	} else if (val & LEDC_INT_STS_REG_FIFO_CPUREQ_INT) {
+		/* Continue the current transfer. */
+		sun50i_r329_ledc_pio_xfer(priv, 0);
+	}
+
+	writel(val, priv->base + LEDC_INT_STS_REG);
+
+	return IRQ_HANDLED;
+}
+
+static void sun50i_r329_ledc_brightness_set(struct led_classdev *cdev,
+					    enum led_brightness brightness)
+{
+	struct sun50i_r329_ledc *priv = dev_get_drvdata(cdev->dev->parent);
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
+	struct sun50i_r329_ledc_led *led = to_ledc_led(mc_cdev);
+	int addr = led - priv->leds;
+	unsigned long flags;
+	bool xfer_active;
+	int next_length;
+
+	led_mc_calc_color_components(mc_cdev, brightness);
+
+	priv->buffer[addr] = led->subled_info[0].brightness << 16 |
+			     led->subled_info[1].brightness <<  8 |
+			     led->subled_info[2].brightness;
+
+	dev_dbg(priv->dev, "LED %d -> #%06x\n", addr, priv->buffer[addr]);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	next_length = max(priv->next_length, addr + 1);
+	xfer_active = priv->xfer_active;
+	if (xfer_active)
+		priv->next_length = next_length;
+	else
+		priv->xfer_active = true;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	if (!xfer_active)
+		sun50i_r329_ledc_start_xfer(priv, next_length);
+}
+
+static const char *const sun50i_r329_ledc_formats[] = {
+	"rgb",
+	"rbg",
+	"grb",
+	"gbr",
+	"brg",
+	"bgr",
+};
+
+static int sun50i_r329_ledc_parse_format(const struct device_node *np,
+					 struct sun50i_r329_ledc *priv)
+{
+	const char *format = "grb";
+	u32 i;
+
+	of_property_read_string(np, "format", &format);
+
+	for (i = 0; i < ARRAY_SIZE(sun50i_r329_ledc_formats); ++i) {
+		if (!strcmp(format, sun50i_r329_ledc_formats[i])) {
+			priv->format = i;
+			return 0;
+		}
+	}
+
+	dev_err(priv->dev, "Bad pixel format '%s'\n", format);
+
+	return -EINVAL;
+}
+
+static void sun50i_r329_ledc_set_format(struct sun50i_r329_ledc *priv)
+{
+	u32 val;
+
+	val = readl(priv->base + LEDC_CTRL_REG);
+	val &= ~LEDC_CTRL_REG_RGB_MODE;
+	val |= priv->format << 6;
+	writel(val, priv->base + LEDC_CTRL_REG);
+}
+
+static const struct sun50i_r329_ledc_timing sun50i_r329_ledc_default_timing = {
+	.t0h_ns = 336,
+	.t0l_ns = 840,
+	.t1h_ns = 882,
+	.t1l_ns = 294,
+	.treset_ns = 300000,
+};
+
+static int sun50i_r329_ledc_parse_timing(const struct device_node *np,
+					 struct sun50i_r329_ledc *priv)
+{
+	struct sun50i_r329_ledc_timing *timing = &priv->timing;
+
+	*timing = sun50i_r329_ledc_default_timing;
+
+	of_property_read_u32(np, "t0h-ns", &timing->t0h_ns);
+	of_property_read_u32(np, "t0l-ns", &timing->t0l_ns);
+	of_property_read_u32(np, "t1h-ns", &timing->t1h_ns);
+	of_property_read_u32(np, "t1l-ns", &timing->t1l_ns);
+	of_property_read_u32(np, "treset-ns", &timing->treset_ns);
+
+	return 0;
+}
+
+static void sun50i_r329_ledc_set_timing(struct sun50i_r329_ledc *priv)
+{
+	const struct sun50i_r329_ledc_timing *timing = &priv->timing;
+	unsigned long mod_freq = clk_get_rate(priv->mod_clk);
+	u32 cycle_ns = NSEC_PER_SEC / mod_freq;
+	u32 val;
+
+	val = (timing->t1h_ns / cycle_ns) << 21 |
+	      (timing->t1l_ns / cycle_ns) << 16 |
+	      (timing->t0h_ns / cycle_ns) <<  6 |
+	      (timing->t0l_ns / cycle_ns);
+	writel(val, priv->base + LEDC_T01_TIMING_CTRL_REG);
+
+	val = (timing->treset_ns / cycle_ns) << 16 |
+	      (priv->num_leds - 1);
+	writel(val, priv->base + LEDC_RESET_TIMING_CTRL_REG);
+}
+
+static int sun50i_r329_ledc_resume(struct device *dev)
+{
+	struct sun50i_r329_ledc *priv = dev_get_drvdata(dev);
+	u32 val;
+	int ret;
+
+	ret = regulator_enable(priv->vled);
+	if (ret)
+		return ret;
+
+	ret = reset_control_deassert(priv->reset);
+	if (ret)
+		goto err_disable_regulator;
+
+	ret = clk_prepare_enable(priv->bus_clk);
+	if (ret)
+		goto err_assert_reset;
+
+	ret = clk_prepare_enable(priv->mod_clk);
+	if (ret)
+		goto err_disable_bus_clk;
+
+	sun50i_r329_ledc_set_format(priv);
+	sun50i_r329_ledc_set_timing(priv);
+
+	/* The trigger level must be at least the burst length. */
+	val = readl(priv->base + LEDC_DMA_CTRL_REG);
+	val &= ~LEDC_DMA_CTRL_REG_FIFO_TRIG_LEVEL;
+	val |= LEDC_FIFO_DEPTH / 2;
+	writel(val, priv->base + LEDC_DMA_CTRL_REG);
+
+	val = LEDC_INT_CTRL_REG_GLOBAL_INT_EN |
+	      LEDC_INT_CTRL_REG_TRANS_FINISH_INT_EN;
+	writel(val, priv->base + LEDC_INT_CTRL_REG);
+
+	return 0;
+
+err_disable_bus_clk:
+	clk_disable_unprepare(priv->bus_clk);
+err_assert_reset:
+	reset_control_assert(priv->reset);
+err_disable_regulator:
+	regulator_disable(priv->vled);
+
+	return ret;
+}
+
+static int sun50i_r329_ledc_suspend(struct device *dev)
+{
+	struct sun50i_r329_ledc *priv = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(priv->mod_clk);
+	clk_disable_unprepare(priv->bus_clk);
+	reset_control_assert(priv->reset);
+	regulator_disable(priv->vled);
+
+	return 0;
+}
+
+static void sun50i_r329_ledc_dma_cleanup(void *data)
+{
+	struct sun50i_r329_ledc *priv = data;
+	struct device *dma_dev = dmaengine_get_dma_device(priv->dma_chan);
+
+	if (priv->buffer)
+		dma_free_wc(dma_dev, LEDS_TO_BYTES(priv->num_leds),
+			    priv->buffer, priv->dma_handle);
+	dma_release_channel(priv->dma_chan);
+}
+
+static int sun50i_r329_ledc_probe(struct platform_device *pdev)
+{
+	const struct device_node *np = pdev->dev.of_node;
+	struct dma_slave_config dma_cfg = {};
+	struct led_init_data init_data = {};
+	struct device *dev = &pdev->dev;
+	struct device_node *child;
+	struct sun50i_r329_ledc *priv;
+	struct resource *mem;
+	int count, irq, ret;
+
+	count = of_get_available_child_count(np);
+	if (!count)
+		return -ENODEV;
+	if (count > LEDC_MAX_LEDS) {
+		dev_err(dev, "Too many LEDs! (max is %d)\n", LEDC_MAX_LEDS);
+		return -EINVAL;
+	}
+
+	priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->num_leds = count;
+	spin_lock_init(&priv->lock);
+	dev_set_drvdata(dev, priv);
+
+	ret = sun50i_r329_ledc_parse_format(np, priv);
+	if (ret)
+		return ret;
+
+	ret = sun50i_r329_ledc_parse_timing(np, priv);
+	if (ret)
+		return ret;
+
+	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->bus_clk = devm_clk_get(dev, "bus");
+	if (IS_ERR(priv->bus_clk))
+		return PTR_ERR(priv->bus_clk);
+
+	priv->mod_clk = devm_clk_get(dev, "mod");
+	if (IS_ERR(priv->mod_clk))
+		return PTR_ERR(priv->mod_clk);
+
+	priv->reset = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(priv->reset))
+		return PTR_ERR(priv->reset);
+
+	priv->vled = devm_regulator_get(dev, "vled");
+	if (IS_ERR(priv->vled))
+		return PTR_ERR(priv->vled);
+
+	priv->dma_chan = dma_request_chan(dev, "tx");
+	if (IS_ERR(priv->dma_chan))
+		return PTR_ERR(priv->dma_chan);
+
+	ret = devm_add_action_or_reset(dev, sun50i_r329_ledc_dma_cleanup, priv);
+	if (ret)
+		return ret;
+
+	dma_cfg.dst_addr	= mem->start + LEDC_DATA_REG;
+	dma_cfg.dst_addr_width	= DMA_SLAVE_BUSWIDTH_4_BYTES;
+	dma_cfg.dst_maxburst	= LEDC_FIFO_DEPTH / 2;
+	ret = dmaengine_slave_config(priv->dma_chan, &dma_cfg);
+	if (ret)
+		return ret;
+
+	priv->buffer = dma_alloc_wc(dmaengine_get_dma_device(priv->dma_chan),
+				    LEDS_TO_BYTES(priv->num_leds),
+				    &priv->dma_handle, GFP_KERNEL);
+	if (!priv->buffer)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_irq(dev, irq, sun50i_r329_ledc_irq,
+			       0, dev_name(dev), priv);
+	if (ret)
+		return ret;
+
+	ret = sun50i_r329_ledc_resume(dev);
+	if (ret)
+		return ret;
+
+	for_each_available_child_of_node(np, child) {
+		struct sun50i_r329_ledc_led *led;
+		struct led_classdev *cdev;
+		u32 addr, color;
+
+		ret = of_property_read_u32(child, "reg", &addr);
+		if (ret || addr >= count) {
+			dev_err(dev, "LED 'reg' values must be from 0 to %d\n",
+				priv->num_leds - 1);
+			ret = -EINVAL;
+			goto err_put_child;
+		}
+
+		ret = of_property_read_u32(child, "color", &color);
+		if (ret || color != LED_COLOR_ID_RGB) {
+			dev_err(dev, "LED 'color' must be LED_COLOR_ID_RGB\n");
+			ret = -EINVAL;
+			goto err_put_child;
+		}
+
+		led = &priv->leds[addr];
+
+		led->subled_info[0].color_index = LED_COLOR_ID_RED;
+		led->subled_info[0].channel = 0;
+		led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
+		led->subled_info[1].channel = 1;
+		led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
+		led->subled_info[2].channel = 2;
+
+		led->mc_cdev.num_colors = ARRAY_SIZE(led->subled_info);
+		led->mc_cdev.subled_info = led->subled_info;
+
+		cdev = &led->mc_cdev.led_cdev;
+		cdev->max_brightness = U8_MAX;
+		cdev->brightness_set = sun50i_r329_ledc_brightness_set;
+
+		init_data.fwnode = of_fwnode_handle(child);
+
+		ret = devm_led_classdev_multicolor_register_ext(dev,
+								&led->mc_cdev,
+								&init_data);
+		if (ret) {
+			dev_err(dev, "Failed to register LED %u: %d\n",
+				addr, ret);
+			goto err_put_child;
+		}
+	}
+
+	dev_info(dev, "Registered %d LEDs\n", priv->num_leds);
+
+	return 0;
+
+err_put_child:
+	of_node_put(child);
+	sun50i_r329_ledc_suspend(&pdev->dev);
+
+	return ret;
+}
+
+static int sun50i_r329_ledc_remove(struct platform_device *pdev)
+{
+	sun50i_r329_ledc_suspend(&pdev->dev);
+
+	return 0;
+}
+
+static void sun50i_r329_ledc_shutdown(struct platform_device *pdev)
+{
+	sun50i_r329_ledc_suspend(&pdev->dev);
+}
+
+static const struct of_device_id sun50i_r329_ledc_of_match[] = {
+	{ .compatible = "allwinner,sun50i-r329-ledc" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sun50i_r329_ledc_of_match);
+
+static SIMPLE_DEV_PM_OPS(sun50i_r329_ledc_pm,
+			 sun50i_r329_ledc_suspend, sun50i_r329_ledc_resume);
+
+static struct platform_driver sun50i_r329_ledc_driver = {
+	.probe		= sun50i_r329_ledc_probe,
+	.remove		= sun50i_r329_ledc_remove,
+	.shutdown	= sun50i_r329_ledc_shutdown,
+	.driver		= {
+		.name		= "sun50i-r329-ledc",
+		.of_match_table	= sun50i_r329_ledc_of_match,
+		.pm		= pm_ptr(&sun50i_r329_ledc_pm),
+	},
+};
+module_platform_driver(sun50i_r329_ledc_driver);
+
+MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
+MODULE_DESCRIPTION("Allwinner R329 LED controller driver");
+MODULE_LICENSE("GPL");
-- 
2.32.0

Re: [PATCH v2 2/2] leds: sunxi: New driver for the R329/D1 LED controller

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3252 bytes --]

Hi Samuel,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on pavel-leds/for-next]
[also build test ERROR on robh/for-next sunxi/sunxi/for-next v5.15-rc3 next-20210922]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Samuel-Holland/dt-bindings-leds-Add-Allwinner-R329-D1-LED-controller/20211004-102621
base:   git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds.git for-next
config: parisc-allyesconfig (attached as .config)
compiler: hppa-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/d34f1e4daaad9848622b4395c5f780fe9f8502cc
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Samuel-Holland/dt-bindings-leds-Add-Allwinner-R329-D1-LED-controller/20211004-102621
        git checkout d34f1e4daaad9848622b4395c5f780fe9f8502cc
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=parisc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/leds/leds-sun50i-r329.c: In function 'sun50i_r329_ledc_pio_xfer':
>> drivers/leds/leds-sun50i-r329.c:125:9: error: implicit declaration of function 'writesl'; did you mean 'writel'? [-Werror=implicit-function-declaration]
     125 |         writesl(priv->base + LEDC_DATA_REG, priv->buffer + offset, burst);
         |         ^~~~~~~
         |         writel
   cc1: all warnings being treated as errors


vim +125 drivers/leds/leds-sun50i-r329.c

   109	
   110	static void sun50i_r329_ledc_pio_xfer(struct sun50i_r329_ledc *priv, int length)
   111	{
   112		u32 burst, offset, val;
   113	
   114		if (length) {
   115			/* New transfer (FIFO is empty). */
   116			offset = 0;
   117			burst  = min(length, LEDC_FIFO_DEPTH);
   118		} else {
   119			/* Existing transfer (FIFO is half-full). */
   120			length = priv->pio_length;
   121			offset = priv->pio_offset;
   122			burst  = min(length, LEDC_FIFO_DEPTH / 2);
   123		}
   124	
 > 125		writesl(priv->base + LEDC_DATA_REG, priv->buffer + offset, burst);
   126	
   127		if (burst < length) {
   128			priv->pio_length = length - burst;
   129			priv->pio_offset = offset + burst;
   130	
   131			if (!offset) {
   132				val = readl(priv->base + LEDC_INT_CTRL_REG);
   133				val |= LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN;
   134				writel(val, priv->base + LEDC_INT_CTRL_REG);
   135			}
   136		} else {
   137			/* Disable the request IRQ once all data is written. */
   138			val = readl(priv->base + LEDC_INT_CTRL_REG);
   139			val &= ~LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN;
   140			writel(val, priv->base + LEDC_INT_CTRL_REG);
   141		}
   142	}
   143	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 69374 bytes --]

Re: [PATCH v2 1/2] dt-bindings: leds: Add Allwinner R329/D1 LED controller

[Rob Herring]

On Sun, Oct 03, 2021 at 09:26:00PM -0500, Samuel Holland wrote:
> The Allwinner R329 and D1 SoCs contain an LED controller designed to
> drive a series of RGB LED pixels. It supports PIO and DMA transfers, and
> has configurable timing and pixel format.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
> 
> Changes from v1:
>  - Fixed typo leading to duplicate t1h-ns property
>  - Removed "items" layer in definition of dmas/dma-names
>  - Replaced uint32 type reference with maxItems in timing properties
> 
>  .../leds/allwinner,sun50i-r329-ledc.yaml      | 140 ++++++++++++++++++
>  1 file changed, 140 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml b/Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml
> new file mode 100644
> index 000000000000..d70cb2393a2e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/allwinner,sun50i-r329-ledc.yaml
> @@ -0,0 +1,140 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/allwinner,sun50i-r329-ledc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Allwinner R329 LED Controller Bindings
> +
> +maintainers:
> +  - Samuel Holland <samuel@sholland.org>
> +
> +description:
> +  The LED controller found in Allwinner sunxi SoCs uses a one-wire serial
> +  interface to drive up to 1024 RGB LEDs.
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - const: allwinner,sun50i-r329-ledc
> +      - items:
> +          - enum:
> +              - allwinner,sun20i-d1-ledc
> +          - const: allwinner,sun50i-r329-ledc
> +
> +  reg:
> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +  clocks:
> +    items:
> +      - description: Bus clock
> +      - description: Module clock
> +
> +  clock-names:
> +    items:
> +      - const: bus
> +      - const: mod
> +
> +  resets:
> +    maxItems: 1
> +
> +  dmas:
> +    maxItems: 1
> +    description: TX DMA channel
> +
> +  dma-names:
> +    const: tx
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  vled-supply:
> +    description: Regulator supplying power to external LEDs
> +
> +  format:
> +    description: Pixel format (subpixel transmission order), default is "grb"
> +    enum:
> +      - "bgr"
> +      - "brg"
> +      - "gbr"
> +      - "grb"
> +      - "rbg"
> +      - "rgb"

Don't need quotes.

> +
> +  t0h-ns:
> +    maxItems: 1
> +    description: Length of high pulse when transmitting a "0" bit
> +
> +  t0l-ns:
> +    maxItems: 1
> +    description: Length of low pulse when transmitting a "0" bit
> +
> +  t1h-ns:
> +    maxItems: 1
> +    description: Length of high pulse when transmitting a "1" bit
> +
> +  t1l-ns:
> +    maxItems: 1
> +    description: Length of low pulse when transmitting a "1" bit
> +
> +  treset-ns:

All these need a vendor prefix.

> +    maxItems: 1
> +    description: Minimum delay between transmission frames
> +
> +patternProperties:
> +  "^multi-led@[0-9a-f]+$":
> +    type: object
> +    $ref: leds-class-multicolor.yaml#
> +    properties:
> +      reg:
> +        minimum: 0
> +        maximum: 1023
> +        description: Index of the LED in the series (must be contiguous)
> +
> +    required:
> +      - reg
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - resets
> +  - dmas
> +  - dma-names
> +  - interrupts
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/leds/common.h>
> +
> +    ledc: led-controller@2008000 {
> +      compatible = "allwinner,sun20i-d1-ledc",
> +                   "allwinner,sun50i-r329-ledc";
> +      reg = <0x2008000 0x400>;
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      clocks = <&ccu 12>, <&ccu 34>;
> +      clock-names = "bus", "mod";
> +      resets = <&ccu 12>;
> +      dmas = <&dma 42>;
> +      dma-names = "tx";
> +      interrupts = <36 IRQ_TYPE_LEVEL_HIGH>;
> +
> +      multi-led@0 {
> +        reg = <0x0>;
> +        color = <LED_COLOR_ID_RGB>;
> +        function = LED_FUNCTION_INDICATOR;
> +      };
> +    };
> +
> +...
> -- 
> 2.32.0
> 
> 

Re: [PATCH v2 2/2] leds: sunxi: New driver for the R329/D1 LED controller

[Heinrich Schuchardt]

On 10/4/21 04:26, Samuel Holland wrote:
> Some Allwinner sunxi SoCs, starting with the R329, contain an LED
> controller designed to drive RGB LED pixels. Add a driver for it using
> the multicolor LED framework, and with LEDs defined in the device tree.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
> 
> Changes from v1:
>   - Renamed from sunxi-ledc to sun50i-r329-ledc
>   - Added missing "static" to functions/globals as reported by 0day bot
> 
>   drivers/leds/Kconfig            |   8 +
>   drivers/leds/Makefile           |   1 +
>   drivers/leds/leds-sun50i-r329.c | 566 ++++++++++++++++++++++++++++++++
>   3 files changed, 575 insertions(+)
>   create mode 100644 drivers/leds/leds-sun50i-r329.c
> 
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index ed800f5da7d8..d5c1396788fe 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -297,6 +297,14 @@ config LEDS_SUNFIRE
>   	  This option enables support for the Left, Middle, and Right
>   	  LEDs on the I/O and CPU boards of SunFire UltraSPARC servers.
>   
> +config LEDS_SUN50I_R329
> +	tristate "LED support for Allwinner R329 LED controller"
> +	depends on LEDS_CLASS

This should be

     depends on LEDS_CLASS_MULTICOLOR

as you are using the multicolor LED framework, e.g. function 
devm_led_classdev_multicolor_register_ext().

Best regards

Heinrich

> +	depends on ARCH_SUNXI || COMPILE_TEST
> +	help
> +	  This option enables support for the RGB LED controller
> +	  provided in some Allwinner sunxi SoCs, like the R329.
> +
>   config LEDS_IPAQ_MICRO
>   	tristate "LED Support for the Compaq iPAQ h3xxx"
>   	depends on LEDS_CLASS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index c636ec069612..506b2617099d 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_PWM)			+= leds-pwm.o
>   obj-$(CONFIG_LEDS_REGULATOR)		+= leds-regulator.o
>   obj-$(CONFIG_LEDS_S3C24XX)		+= leds-s3c24xx.o
>   obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o
> +obj-$(CONFIG_LEDS_SUN50I_R329)		+= leds-sun50i-r329.o
>   obj-$(CONFIG_LEDS_SUNFIRE)		+= leds-sunfire.o
>   obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o
>   obj-$(CONFIG_LEDS_TCA6507)		+= leds-tca6507.o
> diff --git a/drivers/leds/leds-sun50i-r329.c b/drivers/leds/leds-sun50i-r329.c
> new file mode 100644
> index 000000000000..3dfa1840a745
> --- /dev/null
> +++ b/drivers/leds/leds-sun50i-r329.c
> @@ -0,0 +1,566 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (c) 2021 Samuel Holland <samuel@sholland.org>
> +//
> +// Partly based on drivers/leds/leds-turris-omnia.c, which is:
> +//     Copyright (c) 2020 by Marek Behún <kabel@kernel.org>
> +//
> +
> +#include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dmaengine.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/led-class-multicolor.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/reset.h>
> +#include <linux/spinlock.h>
> +
> +#define LEDC_CTRL_REG			0x0000
> +#define LEDC_CTRL_REG_DATA_LENGTH		(0x1fff << 16)
> +#define LEDC_CTRL_REG_RGB_MODE			(0x7 << 6)
> +#define LEDC_CTRL_REG_LEDC_EN			BIT(0)
> +#define LEDC_T01_TIMING_CTRL_REG	0x0004
> +#define LEDC_T01_TIMING_CTRL_REG_T1H		(0x3f << 21)
> +#define LEDC_T01_TIMING_CTRL_REG_T1L		(0x1f << 16)
> +#define LEDC_T01_TIMING_CTRL_REG_T0H		(0x1f << 6)
> +#define LEDC_T01_TIMING_CTRL_REG_T0L		(0x3f << 0)
> +#define LEDC_RESET_TIMING_CTRL_REG	0x000c
> +#define LEDC_RESET_TIMING_CTRL_REG_LED_NUM	(0x3ff << 0)
> +#define LEDC_DATA_REG			0x0014
> +#define LEDC_DMA_CTRL_REG		0x0018
> +#define LEDC_DMA_CTRL_REG_FIFO_TRIG_LEVEL	(0x1f << 0)
> +#define LEDC_INT_CTRL_REG		0x001c
> +#define LEDC_INT_CTRL_REG_GLOBAL_INT_EN		BIT(5)
> +#define LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN	BIT(1)
> +#define LEDC_INT_CTRL_REG_TRANS_FINISH_INT_EN	BIT(0)
> +#define LEDC_INT_STS_REG		0x0020
> +#define LEDC_INT_STS_REG_FIFO_CPUREQ_INT	BIT(1)
> +#define LEDC_INT_STS_REG_TRANS_FINISH_INT	BIT(0)
> +
> +#define LEDC_FIFO_DEPTH			32
> +#define LEDC_MAX_LEDS			1024
> +
> +#define LEDS_TO_BYTES(n)		((n) * sizeof(u32))
> +
> +struct sun50i_r329_ledc_led {
> +	struct led_classdev_mc mc_cdev;
> +	struct mc_subled subled_info[3];
> +};
> +#define to_ledc_led(mc) container_of(mc, struct sun50i_r329_ledc_led, mc_cdev)
> +
> +struct sun50i_r329_ledc_timing {
> +	u32 t0h_ns;
> +	u32 t0l_ns;
> +	u32 t1h_ns;
> +	u32 t1l_ns;
> +	u32 treset_ns;
> +};
> +
> +struct sun50i_r329_ledc {
> +	struct device *dev;
> +	void __iomem *base;
> +	struct clk *bus_clk;
> +	struct clk *mod_clk;
> +	struct reset_control *reset;
> +	struct regulator *vled;
> +
> +	u32 *buffer;
> +	struct dma_chan *dma_chan;
> +	dma_addr_t dma_handle;
> +	int pio_length;
> +	int pio_offset;
> +
> +	spinlock_t lock;
> +	int next_length;
> +	bool xfer_active;
> +
> +	u32 format;
> +	struct sun50i_r329_ledc_timing timing;
> +
> +	int num_leds;
> +	struct sun50i_r329_ledc_led leds[];
> +};
> +
> +static int sun50i_r329_ledc_dma_xfer(struct sun50i_r329_ledc *priv, int length)
> +{
> +	struct dma_async_tx_descriptor *desc;
> +	dma_cookie_t cookie;
> +
> +	desc = dmaengine_prep_slave_single(priv->dma_chan, priv->dma_handle,
> +					   LEDS_TO_BYTES(length),
> +					   DMA_MEM_TO_DEV, 0);
> +	if (!desc)
> +		return -ENOMEM;
> +
> +	cookie = dmaengine_submit(desc);
> +	if (dma_submit_error(cookie))
> +		return -EIO;
> +
> +	dma_async_issue_pending(priv->dma_chan);
> +
> +	return 0;
> +}
> +
> +static void sun50i_r329_ledc_pio_xfer(struct sun50i_r329_ledc *priv, int length)
> +{
> +	u32 burst, offset, val;
> +
> +	if (length) {
> +		/* New transfer (FIFO is empty). */
> +		offset = 0;
> +		burst  = min(length, LEDC_FIFO_DEPTH);
> +	} else {
> +		/* Existing transfer (FIFO is half-full). */
> +		length = priv->pio_length;
> +		offset = priv->pio_offset;
> +		burst  = min(length, LEDC_FIFO_DEPTH / 2);
> +	}
> +
> +	writesl(priv->base + LEDC_DATA_REG, priv->buffer + offset, burst);
> +
> +	if (burst < length) {
> +		priv->pio_length = length - burst;
> +		priv->pio_offset = offset + burst;
> +
> +		if (!offset) {
> +			val = readl(priv->base + LEDC_INT_CTRL_REG);
> +			val |= LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN;
> +			writel(val, priv->base + LEDC_INT_CTRL_REG);
> +		}
> +	} else {
> +		/* Disable the request IRQ once all data is written. */
> +		val = readl(priv->base + LEDC_INT_CTRL_REG);
> +		val &= ~LEDC_INT_CTRL_REG_FIFO_CPUREQ_INT_EN;
> +		writel(val, priv->base + LEDC_INT_CTRL_REG);
> +	}
> +}
> +
> +static void sun50i_r329_ledc_start_xfer(struct sun50i_r329_ledc *priv,
> +					int length)
> +{
> +	u32 val;
> +
> +	dev_dbg(priv->dev, "Updating %d LEDs\n", length);
> +
> +	val = readl(priv->base + LEDC_CTRL_REG);
> +	val &= ~LEDC_CTRL_REG_DATA_LENGTH;
> +	val |= length << 16 | LEDC_CTRL_REG_LEDC_EN;
> +	writel(val, priv->base + LEDC_CTRL_REG);
> +
> +	if (length > LEDC_FIFO_DEPTH) {
> +		int ret = sun50i_r329_ledc_dma_xfer(priv, length);
> +
> +		if (!ret)
> +			return;
> +
> +		dev_warn(priv->dev, "Failed to set up DMA: %d\n", ret);
> +	}
> +
> +	sun50i_r329_ledc_pio_xfer(priv, length);
> +}
> +
> +static irqreturn_t sun50i_r329_ledc_irq(int irq, void *dev_id)
> +{
> +	struct sun50i_r329_ledc *priv = dev_id;
> +	u32 val;
> +
> +	val = readl(priv->base + LEDC_INT_STS_REG);
> +
> +	if (val & LEDC_INT_STS_REG_TRANS_FINISH_INT) {
> +		int next_length;
> +
> +		/* Start the next transfer if needed. */
> +		spin_lock(&priv->lock);
> +		next_length = priv->next_length;
> +		if (next_length)
> +			priv->next_length = 0;
> +		else
> +			priv->xfer_active = false;
> +		spin_unlock(&priv->lock);
> +
> +		if (next_length)
> +			sun50i_r329_ledc_start_xfer(priv, next_length);
> +	} else if (val & LEDC_INT_STS_REG_FIFO_CPUREQ_INT) {
> +		/* Continue the current transfer. */
> +		sun50i_r329_ledc_pio_xfer(priv, 0);
> +	}
> +
> +	writel(val, priv->base + LEDC_INT_STS_REG);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void sun50i_r329_ledc_brightness_set(struct led_classdev *cdev,
> +					    enum led_brightness brightness)
> +{
> +	struct sun50i_r329_ledc *priv = dev_get_drvdata(cdev->dev->parent);
> +	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
> +	struct sun50i_r329_ledc_led *led = to_ledc_led(mc_cdev);
> +	int addr = led - priv->leds;
> +	unsigned long flags;
> +	bool xfer_active;
> +	int next_length;
> +
> +	led_mc_calc_color_components(mc_cdev, brightness);
> +
> +	priv->buffer[addr] = led->subled_info[0].brightness << 16 |
> +			     led->subled_info[1].brightness <<  8 |
> +			     led->subled_info[2].brightness;
> +
> +	dev_dbg(priv->dev, "LED %d -> #%06x\n", addr, priv->buffer[addr]);
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +	next_length = max(priv->next_length, addr + 1);
> +	xfer_active = priv->xfer_active;
> +	if (xfer_active)
> +		priv->next_length = next_length;
> +	else
> +		priv->xfer_active = true;
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	if (!xfer_active)
> +		sun50i_r329_ledc_start_xfer(priv, next_length);
> +}
> +
> +static const char *const sun50i_r329_ledc_formats[] = {
> +	"rgb",
> +	"rbg",
> +	"grb",
> +	"gbr",
> +	"brg",
> +	"bgr",
> +};
> +
> +static int sun50i_r329_ledc_parse_format(const struct device_node *np,
> +					 struct sun50i_r329_ledc *priv)
> +{
> +	const char *format = "grb";
> +	u32 i;
> +
> +	of_property_read_string(np, "format", &format);
> +
> +	for (i = 0; i < ARRAY_SIZE(sun50i_r329_ledc_formats); ++i) {
> +		if (!strcmp(format, sun50i_r329_ledc_formats[i])) {
> +			priv->format = i;
> +			return 0;
> +		}
> +	}
> +
> +	dev_err(priv->dev, "Bad pixel format '%s'\n", format);
> +
> +	return -EINVAL;
> +}
> +
> +static void sun50i_r329_ledc_set_format(struct sun50i_r329_ledc *priv)
> +{
> +	u32 val;
> +
> +	val = readl(priv->base + LEDC_CTRL_REG);
> +	val &= ~LEDC_CTRL_REG_RGB_MODE;
> +	val |= priv->format << 6;
> +	writel(val, priv->base + LEDC_CTRL_REG);
> +}
> +
> +static const struct sun50i_r329_ledc_timing sun50i_r329_ledc_default_timing = {
> +	.t0h_ns = 336,
> +	.t0l_ns = 840,
> +	.t1h_ns = 882,
> +	.t1l_ns = 294,
> +	.treset_ns = 300000,
> +};
> +
> +static int sun50i_r329_ledc_parse_timing(const struct device_node *np,
> +					 struct sun50i_r329_ledc *priv)
> +{
> +	struct sun50i_r329_ledc_timing *timing = &priv->timing;
> +
> +	*timing = sun50i_r329_ledc_default_timing;
> +
> +	of_property_read_u32(np, "t0h-ns", &timing->t0h_ns);
> +	of_property_read_u32(np, "t0l-ns", &timing->t0l_ns);
> +	of_property_read_u32(np, "t1h-ns", &timing->t1h_ns);
> +	of_property_read_u32(np, "t1l-ns", &timing->t1l_ns);
> +	of_property_read_u32(np, "treset-ns", &timing->treset_ns);
> +
> +	return 0;
> +}
> +
> +static void sun50i_r329_ledc_set_timing(struct sun50i_r329_ledc *priv)
> +{
> +	const struct sun50i_r329_ledc_timing *timing = &priv->timing;
> +	unsigned long mod_freq = clk_get_rate(priv->mod_clk);
> +	u32 cycle_ns = NSEC_PER_SEC / mod_freq;
> +	u32 val;
> +
> +	val = (timing->t1h_ns / cycle_ns) << 21 |
> +	      (timing->t1l_ns / cycle_ns) << 16 |
> +	      (timing->t0h_ns / cycle_ns) <<  6 |
> +	      (timing->t0l_ns / cycle_ns);
> +	writel(val, priv->base + LEDC_T01_TIMING_CTRL_REG);
> +
> +	val = (timing->treset_ns / cycle_ns) << 16 |
> +	      (priv->num_leds - 1);
> +	writel(val, priv->base + LEDC_RESET_TIMING_CTRL_REG);
> +}
> +
> +static int sun50i_r329_ledc_resume(struct device *dev)
> +{
> +	struct sun50i_r329_ledc *priv = dev_get_drvdata(dev);
> +	u32 val;
> +	int ret;
> +
> +	ret = regulator_enable(priv->vled);
> +	if (ret)
> +		return ret;
> +
> +	ret = reset_control_deassert(priv->reset);
> +	if (ret)
> +		goto err_disable_regulator;
> +
> +	ret = clk_prepare_enable(priv->bus_clk);
> +	if (ret)
> +		goto err_assert_reset;
> +
> +	ret = clk_prepare_enable(priv->mod_clk);
> +	if (ret)
> +		goto err_disable_bus_clk;
> +
> +	sun50i_r329_ledc_set_format(priv);
> +	sun50i_r329_ledc_set_timing(priv);
> +
> +	/* The trigger level must be at least the burst length. */
> +	val = readl(priv->base + LEDC_DMA_CTRL_REG);
> +	val &= ~LEDC_DMA_CTRL_REG_FIFO_TRIG_LEVEL;
> +	val |= LEDC_FIFO_DEPTH / 2;
> +	writel(val, priv->base + LEDC_DMA_CTRL_REG);
> +
> +	val = LEDC_INT_CTRL_REG_GLOBAL_INT_EN |
> +	      LEDC_INT_CTRL_REG_TRANS_FINISH_INT_EN;
> +	writel(val, priv->base + LEDC_INT_CTRL_REG);
> +
> +	return 0;
> +
> +err_disable_bus_clk:
> +	clk_disable_unprepare(priv->bus_clk);
> +err_assert_reset:
> +	reset_control_assert(priv->reset);
> +err_disable_regulator:
> +	regulator_disable(priv->vled);
> +
> +	return ret;
> +}
> +
> +static int sun50i_r329_ledc_suspend(struct device *dev)
> +{
> +	struct sun50i_r329_ledc *priv = dev_get_drvdata(dev);
> +
> +	clk_disable_unprepare(priv->mod_clk);
> +	clk_disable_unprepare(priv->bus_clk);
> +	reset_control_assert(priv->reset);
> +	regulator_disable(priv->vled);
> +
> +	return 0;
> +}
> +
> +static void sun50i_r329_ledc_dma_cleanup(void *data)
> +{
> +	struct sun50i_r329_ledc *priv = data;
> +	struct device *dma_dev = dmaengine_get_dma_device(priv->dma_chan);
> +
> +	if (priv->buffer)
> +		dma_free_wc(dma_dev, LEDS_TO_BYTES(priv->num_leds),
> +			    priv->buffer, priv->dma_handle);
> +	dma_release_channel(priv->dma_chan);
> +}
> +
> +static int sun50i_r329_ledc_probe(struct platform_device *pdev)
> +{
> +	const struct device_node *np = pdev->dev.of_node;
> +	struct dma_slave_config dma_cfg = {};
> +	struct led_init_data init_data = {};
> +	struct device *dev = &pdev->dev;
> +	struct device_node *child;
> +	struct sun50i_r329_ledc *priv;
> +	struct resource *mem;
> +	int count, irq, ret;
> +
> +	count = of_get_available_child_count(np);
> +	if (!count)
> +		return -ENODEV;
> +	if (count > LEDC_MAX_LEDS) {
> +		dev_err(dev, "Too many LEDs! (max is %d)\n", LEDC_MAX_LEDS);
> +		return -EINVAL;
> +	}
> +
> +	priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->dev = dev;
> +	priv->num_leds = count;
> +	spin_lock_init(&priv->lock);
> +	dev_set_drvdata(dev, priv);
> +
> +	ret = sun50i_r329_ledc_parse_format(np, priv);
> +	if (ret)
> +		return ret;
> +
> +	ret = sun50i_r329_ledc_parse_timing(np, priv);
> +	if (ret)
> +		return ret;
> +
> +	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
> +	if (IS_ERR(priv->base))
> +		return PTR_ERR(priv->base);
> +
> +	priv->bus_clk = devm_clk_get(dev, "bus");
> +	if (IS_ERR(priv->bus_clk))
> +		return PTR_ERR(priv->bus_clk);
> +
> +	priv->mod_clk = devm_clk_get(dev, "mod");
> +	if (IS_ERR(priv->mod_clk))
> +		return PTR_ERR(priv->mod_clk);
> +
> +	priv->reset = devm_reset_control_get_exclusive(dev, NULL);
> +	if (IS_ERR(priv->reset))
> +		return PTR_ERR(priv->reset);
> +
> +	priv->vled = devm_regulator_get(dev, "vled");
> +	if (IS_ERR(priv->vled))
> +		return PTR_ERR(priv->vled);
> +
> +	priv->dma_chan = dma_request_chan(dev, "tx");
> +	if (IS_ERR(priv->dma_chan))
> +		return PTR_ERR(priv->dma_chan);
> +
> +	ret = devm_add_action_or_reset(dev, sun50i_r329_ledc_dma_cleanup, priv);
> +	if (ret)
> +		return ret;
> +
> +	dma_cfg.dst_addr	= mem->start + LEDC_DATA_REG;
> +	dma_cfg.dst_addr_width	= DMA_SLAVE_BUSWIDTH_4_BYTES;
> +	dma_cfg.dst_maxburst	= LEDC_FIFO_DEPTH / 2;
> +	ret = dmaengine_slave_config(priv->dma_chan, &dma_cfg);
> +	if (ret)
> +		return ret;
> +
> +	priv->buffer = dma_alloc_wc(dmaengine_get_dma_device(priv->dma_chan),
> +				    LEDS_TO_BYTES(priv->num_leds),
> +				    &priv->dma_handle, GFP_KERNEL);
> +	if (!priv->buffer)
> +		return -ENOMEM;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +
> +	ret = devm_request_irq(dev, irq, sun50i_r329_ledc_irq,
> +			       0, dev_name(dev), priv);
> +	if (ret)
> +		return ret;
> +
> +	ret = sun50i_r329_ledc_resume(dev);
> +	if (ret)
> +		return ret;
> +
> +	for_each_available_child_of_node(np, child) {
> +		struct sun50i_r329_ledc_led *led;
> +		struct led_classdev *cdev;
> +		u32 addr, color;
> +
> +		ret = of_property_read_u32(child, "reg", &addr);
> +		if (ret || addr >= count) {
> +			dev_err(dev, "LED 'reg' values must be from 0 to %d\n",
> +				priv->num_leds - 1);
> +			ret = -EINVAL;
> +			goto err_put_child;
> +		}
> +
> +		ret = of_property_read_u32(child, "color", &color);
> +		if (ret || color != LED_COLOR_ID_RGB) {
> +			dev_err(dev, "LED 'color' must be LED_COLOR_ID_RGB\n");
> +			ret = -EINVAL;
> +			goto err_put_child;
> +		}
> +
> +		led = &priv->leds[addr];
> +
> +		led->subled_info[0].color_index = LED_COLOR_ID_RED;
> +		led->subled_info[0].channel = 0;
> +		led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
> +		led->subled_info[1].channel = 1;
> +		led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
> +		led->subled_info[2].channel = 2;
> +
> +		led->mc_cdev.num_colors = ARRAY_SIZE(led->subled_info);
> +		led->mc_cdev.subled_info = led->subled_info;
> +
> +		cdev = &led->mc_cdev.led_cdev;
> +		cdev->max_brightness = U8_MAX;
> +		cdev->brightness_set = sun50i_r329_ledc_brightness_set;
> +
> +		init_data.fwnode = of_fwnode_handle(child);
> +
> +		ret = devm_led_classdev_multicolor_register_ext(dev,
> +								&led->mc_cdev,
> +								&init_data);
> +		if (ret) {
> +			dev_err(dev, "Failed to register LED %u: %d\n",
> +				addr, ret);
> +			goto err_put_child;
> +		}
> +	}
> +
> +	dev_info(dev, "Registered %d LEDs\n", priv->num_leds);
> +
> +	return 0;
> +
> +err_put_child:
> +	of_node_put(child);
> +	sun50i_r329_ledc_suspend(&pdev->dev);
> +
> +	return ret;
> +}
> +
> +static int sun50i_r329_ledc_remove(struct platform_device *pdev)
> +{
> +	sun50i_r329_ledc_suspend(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +static void sun50i_r329_ledc_shutdown(struct platform_device *pdev)
> +{
> +	sun50i_r329_ledc_suspend(&pdev->dev);
> +}
> +
> +static const struct of_device_id sun50i_r329_ledc_of_match[] = {
> +	{ .compatible = "allwinner,sun50i-r329-ledc" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, sun50i_r329_ledc_of_match);
> +
> +static SIMPLE_DEV_PM_OPS(sun50i_r329_ledc_pm,
> +			 sun50i_r329_ledc_suspend, sun50i_r329_ledc_resume);
> +
> +static struct platform_driver sun50i_r329_ledc_driver = {
> +	.probe		= sun50i_r329_ledc_probe,
> +	.remove		= sun50i_r329_ledc_remove,
> +	.shutdown	= sun50i_r329_ledc_shutdown,
> +	.driver		= {
> +		.name		= "sun50i-r329-ledc",
> +		.of_match_table	= sun50i_r329_ledc_of_match,
> +		.pm		= pm_ptr(&sun50i_r329_ledc_pm),
> +	},
> +};
> +module_platform_driver(sun50i_r329_ledc_driver);
> +
> +MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
> +MODULE_DESCRIPTION("Allwinner R329 LED controller driver");
> +MODULE_LICENSE("GPL");
>