* [PATCH v4 RESEND 1/3] dt-bindings: leds: backlight: apple,dwi-bl: Add Apple DWI backlight
2024-12-29 11:11 [PATCH v4 RESEND 0/3] Apple DWI backlight driver Nick Chan
@ 2024-12-29 11:11 ` Nick Chan
2024-12-29 11:11 ` [PATCH v4 RESEND 2/3] backlight: dwi_bl: Add Apple DWI backlight driver Nick Chan
2024-12-29 11:11 ` [PATCH v4 RESEND 3/3] MAINTAINERS: Add entries for Apple DWI backlight controller Nick Chan
2 siblings, 0 replies; 4+ messages in thread
From: Nick Chan @ 2024-12-29 11:11 UTC (permalink / raw)
To: Hector Martin, Sven Peter, Alyssa Rosenzweig, Lee Jones,
Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Nick Chan, asahi,
linux-arm-kernel, dri-devel, linux-leds, devicetree, linux-kernel,
linux-fbdev
Cc: Krzysztof Kozlowski
Add backlight controllers attached via Apple DWI 2-wire interface.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
---
.../bindings/leds/backlight/apple,dwi-bl.yaml | 57 +++++++++++++++++++
1 file changed, 57 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/apple,dwi-bl.yaml
diff --git a/Documentation/devicetree/bindings/leds/backlight/apple,dwi-bl.yaml b/Documentation/devicetree/bindings/leds/backlight/apple,dwi-bl.yaml
new file mode 100644
index 000000000000..29caeb356e6f
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/apple,dwi-bl.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/apple,dwi-bl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple DWI 2-Wire Interface Backlight Controller
+
+maintainers:
+ - Nick Chan <towinchenmi@gmail.com>
+
+description:
+ Apple SoCs contain a 2-wire interface called DWI. On some Apple iPhones,
+ iPads and iPod touches with a LCD display, 1-2 backlight controllers
+ are connected via DWI. Interfacing with DWI controls all backlight
+ controllers at the same time. As such, the backlight controllers are
+ treated as a single controller regardless of the underlying
+ configuration.
+
+allOf:
+ - $ref: common.yaml#
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - apple,s5l8960x-dwi-bl
+ - apple,t7000-dwi-bl
+ - apple,s8000-dwi-bl
+ - apple,t8010-dwi-bl
+ - apple,t8015-dwi-bl
+ - const: apple,dwi-bl
+
+ reg:
+ maxItems: 1
+
+ power-domains:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ soc {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ dwi_bl: backlight@20e200010 {
+ compatible = "apple,s5l8960x-dwi-bl", "apple,dwi-bl";
+ reg = <0x2 0x0e200010 0x0 0x8>;
+ power-domains = <&ps_dwi>;
+ };
+ };
--
2.47.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v4 RESEND 2/3] backlight: dwi_bl: Add Apple DWI backlight driver
2024-12-29 11:11 [PATCH v4 RESEND 0/3] Apple DWI backlight driver Nick Chan
2024-12-29 11:11 ` [PATCH v4 RESEND 1/3] dt-bindings: leds: backlight: apple,dwi-bl: Add Apple DWI backlight Nick Chan
@ 2024-12-29 11:11 ` Nick Chan
2024-12-29 11:11 ` [PATCH v4 RESEND 3/3] MAINTAINERS: Add entries for Apple DWI backlight controller Nick Chan
2 siblings, 0 replies; 4+ messages in thread
From: Nick Chan @ 2024-12-29 11:11 UTC (permalink / raw)
To: Hector Martin, Sven Peter, Alyssa Rosenzweig, Lee Jones,
Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Nick Chan, asahi,
linux-arm-kernel, dri-devel, linux-leds, devicetree, linux-kernel,
linux-fbdev
Add driver for backlight controllers attached via Apple DWI 2-wire
interface, which is found on some Apple iPhones, iPads and iPod touches
with a LCD display.
Although there is an existing apple_bl driver, it is for backlight
controllers on Intel Macs attached via PCI, which is completely different
from the Samsung-derived DWI block.
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
---
drivers/video/backlight/Kconfig | 12 +++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/dwi_bl.c | 122 +++++++++++++++++++++++++++++++
3 files changed, 135 insertions(+)
create mode 100644 drivers/video/backlight/dwi_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 3614a5d29c71..debb1326df63 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -290,6 +290,18 @@ config BACKLIGHT_APPLE
If you have an Intel-based Apple say Y to enable a driver for its
backlight.
+config BACKLIGHT_APPLE_DWI
+ tristate "Apple DWI 2-Wire Interface Backlight Driver"
+ depends on ARCH_APPLE || COMPILE_TEST
+ default y
+ help
+ Say Y to enable the backlight driver for backlight controllers
+ attached via the Apple DWI 2-wire interface which is found in some
+ Apple iPhones, iPads and iPod touches.
+
+ To compile this driver as a module, choose M here: the module will
+ be called dwi_bl.
+
config BACKLIGHT_QCOM_WLED
tristate "Qualcomm PMIC WLED Driver"
select REGMAP
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index 8fc98f760a8a..45cc80d9ae22 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_BACKLIGHT_ADP5520) += adp5520_bl.o
obj-$(CONFIG_BACKLIGHT_ADP8860) += adp8860_bl.o
obj-$(CONFIG_BACKLIGHT_ADP8870) += adp8870_bl.o
obj-$(CONFIG_BACKLIGHT_APPLE) += apple_bl.o
+obj-$(CONFIG_BACKLIGHT_APPLE_DWI) += dwi_bl.o
obj-$(CONFIG_BACKLIGHT_AS3711) += as3711_bl.o
obj-$(CONFIG_BACKLIGHT_BD6107) += bd6107.o
obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE) += backlight.o
diff --git a/drivers/video/backlight/dwi_bl.c b/drivers/video/backlight/dwi_bl.c
new file mode 100644
index 000000000000..59e5cad0fbd8
--- /dev/null
+++ b/drivers/video/backlight/dwi_bl.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Driver for backlight controllers attached via Apple DWI 2-wire interface
+ *
+ * Copyright (c) 2024 Nick Chan <towinchenmi@gmail.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define DWI_BL_CTL 0x0
+#define DWI_BL_CTL_SEND1 BIT(0)
+#define DWI_BL_CTL_SEND2 BIT(4)
+#define DWI_BL_CTL_SEND3 BIT(5)
+#define DWI_BL_CTL_LE_DATA BIT(6)
+/* Only used on Apple A9 and later */
+#define DWI_BL_CTL_SEND4 BIT(12)
+
+#define DWI_BL_CMD 0x4
+#define DWI_BL_CMD_TYPE GENMASK(31, 28)
+#define DWI_BL_CMD_TYPE_SET_BRIGHTNESS 0xa
+#define DWI_BL_CMD_DATA GENMASK(10, 0)
+
+#define DWI_BL_CTL_SEND (DWI_BL_CTL_SEND1 | \
+ DWI_BL_CTL_SEND2 | \
+ DWI_BL_CTL_SEND3 | \
+ DWI_BL_CTL_LE_DATA | \
+ DWI_BL_CTL_SEND4)
+
+#define DWI_BL_MAX_BRIGHTNESS 2047
+
+struct apple_dwi_bl {
+ void __iomem *base;
+};
+
+static int dwi_bl_update_status(struct backlight_device *bl)
+{
+ struct apple_dwi_bl *dwi_bl = bl_get_data(bl);
+
+ int brightness = backlight_get_brightness(bl);
+
+ u32 cmd = 0;
+
+ cmd |= FIELD_PREP(DWI_BL_CMD_DATA, brightness);
+ cmd |= FIELD_PREP(DWI_BL_CMD_TYPE, DWI_BL_CMD_TYPE_SET_BRIGHTNESS);
+
+ writel(cmd, dwi_bl->base + DWI_BL_CMD);
+ writel(DWI_BL_CTL_SEND, dwi_bl->base + DWI_BL_CTL);
+
+ return 0;
+}
+
+static int dwi_bl_get_brightness(struct backlight_device *bl)
+{
+ struct apple_dwi_bl *dwi_bl = bl_get_data(bl);
+
+ u32 cmd = readl(dwi_bl->base + DWI_BL_CMD);
+
+ return FIELD_GET(DWI_BL_CMD_DATA, cmd);
+}
+
+static const struct backlight_ops dwi_bl_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .get_brightness = dwi_bl_get_brightness,
+ .update_status = dwi_bl_update_status
+};
+
+static int dwi_bl_probe(struct platform_device *dev)
+{
+ struct apple_dwi_bl *dwi_bl;
+ struct backlight_device *bl;
+ struct backlight_properties props;
+ struct resource *res;
+
+ dwi_bl = devm_kzalloc(&dev->dev, sizeof(*dwi_bl), GFP_KERNEL);
+ if (!dwi_bl)
+ return -ENOMEM;
+
+ dwi_bl->base = devm_platform_get_and_ioremap_resource(dev, 0, &res);
+ if (IS_ERR(dwi_bl->base))
+ return PTR_ERR(dwi_bl->base);
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW;
+ props.max_brightness = DWI_BL_MAX_BRIGHTNESS;
+
+ bl = devm_backlight_device_register(&dev->dev, dev->name, &dev->dev,
+ dwi_bl, &dwi_bl_ops, &props);
+ if (IS_ERR(bl))
+ return PTR_ERR(bl);
+
+ platform_set_drvdata(dev, dwi_bl);
+
+ bl->props.brightness = dwi_bl_get_brightness(bl);
+
+ return 0;
+}
+
+static const struct of_device_id dwi_bl_of_match[] = {
+ { .compatible = "apple,dwi-bl" },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, dwi_bl_of_match);
+
+static struct platform_driver dwi_bl_driver = {
+ .driver = {
+ .name = "dwi-bl",
+ .of_match_table = dwi_bl_of_match
+ },
+ .probe = dwi_bl_probe,
+};
+
+module_platform_driver(dwi_bl_driver);
+
+MODULE_DESCRIPTION("Apple DWI Backlight Driver");
+MODULE_AUTHOR("Nick Chan <towinchenmi@gmail.com>");
+MODULE_LICENSE("Dual MIT/GPL");
--
2.47.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v4 RESEND 3/3] MAINTAINERS: Add entries for Apple DWI backlight controller
2024-12-29 11:11 [PATCH v4 RESEND 0/3] Apple DWI backlight driver Nick Chan
2024-12-29 11:11 ` [PATCH v4 RESEND 1/3] dt-bindings: leds: backlight: apple,dwi-bl: Add Apple DWI backlight Nick Chan
2024-12-29 11:11 ` [PATCH v4 RESEND 2/3] backlight: dwi_bl: Add Apple DWI backlight driver Nick Chan
@ 2024-12-29 11:11 ` Nick Chan
2 siblings, 0 replies; 4+ messages in thread
From: Nick Chan @ 2024-12-29 11:11 UTC (permalink / raw)
To: Hector Martin, Sven Peter, Alyssa Rosenzweig, Lee Jones,
Daniel Thompson, Jingoo Han, Pavel Machek, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Helge Deller, Nick Chan, asahi,
linux-arm-kernel, dri-devel, linux-leds, devicetree, linux-kernel,
linux-fbdev
Add MAINTAINERS entries for the driver.
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
---
MAINTAINERS | 2 ++
1 file changed, 2 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 910305c11e8a..54a6c8ca7017 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2196,6 +2196,7 @@ F: Documentation/devicetree/bindings/i2c/apple,i2c.yaml
F: Documentation/devicetree/bindings/interrupt-controller/apple,*
F: Documentation/devicetree/bindings/iommu/apple,dart.yaml
F: Documentation/devicetree/bindings/iommu/apple,sart.yaml
+F: Documentation/devicetree/bindings/leds/backlight/apple,dwi-bl.yaml
F: Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
F: Documentation/devicetree/bindings/net/bluetooth/brcm,bcm4377-bluetooth.yaml
F: Documentation/devicetree/bindings/nvme/apple,nvme-ans.yaml
@@ -2221,6 +2222,7 @@ F: drivers/nvmem/apple-efuses.c
F: drivers/pinctrl/pinctrl-apple-gpio.c
F: drivers/pwm/pwm-apple.c
F: drivers/soc/apple/*
+F: drivers/video/backlight/dwi_bl.c
F: drivers/watchdog/apple_wdt.c
F: include/dt-bindings/interrupt-controller/apple-aic.h
F: include/dt-bindings/pinctrl/apple.h
--
2.47.1
^ permalink raw reply related [flat|nested] 4+ messages in thread