Add support for Skyworks AAT2870 LED Backlight Driver and Multiple LDO
Lighting Management Unit. Only backlight is supported as for now. Supported
backlight level range is from 2 to 255 with step of 1.
Tested-by: Ion Agorria <i...@agorria.com>
Signed-off-by: Svyatoslav Ryhel <clamo...@gmail.com>
---
drivers/video/Kconfig | 10 +++
drivers/video/Makefile | 1 +
drivers/video/aat2870_backlight.c | 132 ++++++++++++++++++++++++++++++
3 files changed, 143 insertions(+)
create mode 100644 drivers/video/aat2870_backlight.c
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 3551aefae89..d855883fad9 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -754,6 +754,16 @@ config ATMEL_HLCD
help
HLCDC supports video output to an attached LCD panel.
+config BACKLIGHT_AAT2870
+ bool "Backlight Driver for AAT2870"
+ depends on BACKLIGHT
+ select DM_I2C
+ help
+ Say Y to enable the backlight driver for Skyworks AAT2870 LED
+ Backlight Driver and Multiple LDO Lighting Management Unit.
+ Only backlight is supported as for now. Supported backlight
+ level range is from 2 to 255 with step of 1.
+
config BACKLIGHT_LM3532
bool "Backlight Driver for LM3532"
depends on BACKLIGHT
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index ccd791cac59..a1bf92d9099 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_$(PHASE_)BMP) += bmp.o
endif
+obj-$(CONFIG_BACKLIGHT_AAT2870) += aat2870_backlight.o
obj-$(CONFIG_BACKLIGHT_LM3532) += lm3532_backlight.o
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_backlight.o
obj-$(CONFIG_BACKLIGHT_LP855x) += lp855x_backlight.o
diff --git a/drivers/video/aat2870_backlight.c
b/drivers/video/aat2870_backlight.c
new file mode 100644
index 00000000000..209d15b3639
--- /dev/null
+++ b/drivers/video/aat2870_backlight.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024 Svyatoslav Ryhel <clamo...@gmail.com>
+ */
+
+#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT
+
+#include <backlight.h>
+#include <dm.h>
+#include <i2c.h>
+#include <log.h>
+#include <linux/err.h>
+#include <asm/gpio.h>
+#include <power/regulator.h>
+
+#define AAT2870_BL_MIN_BRIGHTNESS 0x01
+#define AAT2870_BL_DEF_BRIGHTNESS 0x64
+#define AAT2870_BL_MAX_BRIGHTNESS 0xff
+
+#define AAT2870_BL_CH_EN 0x00
+#define AAT2870_BLM 0x01
+
+#define AAT2870_BL_CH_ALL 0xff
+
+#define AAT2870_CURRENT_MAX 27900000
+#define AAT2870_CURRENT_STEP 900000
+
+struct aat2870_backlight_priv {
+ struct gpio_desc enable_gpio;
+
+ int channels;
+ int max_current;
+};
+
+static int aat2870_backlight_enable(struct udevice *dev)
+{
+ struct aat2870_backlight_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ dm_gpio_set_value(&priv->enable_gpio, 1);
+
+ /* Enable backlight for defined set of channels */
+ ret = dm_i2c_reg_write(dev, AAT2870_BL_CH_EN, priv->channels);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int aat2870_backlight_set_brightness(struct udevice *dev, int percent)
+{
+ struct aat2870_backlight_priv *priv = dev_get_priv(dev);
+ int brightness, ret;
+
+ if (percent == BACKLIGHT_DEFAULT)
+ percent = AAT2870_BL_DEF_BRIGHTNESS;
+
+ if (percent < AAT2870_BL_MIN_BRIGHTNESS)
+ percent = AAT2870_BL_MIN_BRIGHTNESS;
+
+ if (percent > AAT2870_BL_MAX_BRIGHTNESS)
+ percent = AAT2870_BL_MAX_BRIGHTNESS;
+
+ brightness = percent * priv->max_current;
+ brightness /= AAT2870_BL_MAX_BRIGHTNESS;
+
+ /* Set brightness level */
+ ret = dm_i2c_reg_write(dev, AAT2870_BLM, brightness);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int aat2870_backlight_of_to_plat(struct udevice *dev)
+{
+ struct aat2870_backlight_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = gpio_request_by_name(dev, "enable-gpios", 0,
+ &priv->enable_gpio, GPIOD_IS_OUT);
+ if (ret) {
+ log_err("%s: cannot get enable-gpios (%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
+ /* Backlight is one of children but has no dedicated driver */
+ ofnode backlight = ofnode_find_subnode(dev_ofnode(dev), "backlight");
+ if (ofnode_valid(backlight) && ofnode_is_enabled(backlight)) {
+ /* Number of channel is equal to bit number */
+ priv->channels = dev_read_u32_default(dev, "channels",
AAT2870_BL_CH_ALL);
+ if (priv->channels != AAT2870_BL_CH_ALL)
+ priv->channels = BIT(priv->channels);
+
+ /* 450mA - 27900mA range with a 900mA step */
+ priv->max_current = dev_read_u32_default(dev,
"current-max-microamp",
+ AAT2870_CURRENT_MAX);
+ priv->max_current /= AAT2870_CURRENT_STEP;
+ }
+
+ return 0;
+}
+
+static int aat2870_backlight_probe(struct udevice *dev)
+{
+ if (device_get_uclass_id(dev->parent) != UCLASS_I2C)
+ return -EPROTONOSUPPORT;
+
+ return 0;
+}
+
+static const struct backlight_ops aat2870_backlight_ops = {
+ .enable = aat2870_backlight_enable,
+ .set_brightness = aat2870_backlight_set_brightness,
+};
+
+static const struct udevice_id aat2870_backlight_ids[] = {
+ { .compatible = "analogictech,aat2870" },
+ { .compatible = "skyworks,aat2870" },
+ { }
+};
+
+U_BOOT_DRIVER(aat2870_backlight) = {
+ .name = "aat2870_backlight",
+ .id = UCLASS_PANEL_BACKLIGHT,
+ .of_match = aat2870_backlight_ids,
+ .of_to_plat = aat2870_backlight_of_to_plat,
+ .probe = aat2870_backlight_probe,
+ .ops = &aat2870_backlight_ops,
+ .priv_auto = sizeof(struct aat2870_backlight_priv),
+};
--
2.43.0
