diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.9/950-0085-rpi_display-add-backlight-driver-and-overlay.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.9/950-0085-rpi_display-add-backlight-driver-and-overlay.patch | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.9/950-0085-rpi_display-add-backlight-driver-and-overlay.patch b/target/linux/brcm2708/patches-4.9/950-0085-rpi_display-add-backlight-driver-and-overlay.patch new file mode 100644 index 0000000..67c0e3f --- /dev/null +++ b/target/linux/brcm2708/patches-4.9/950-0085-rpi_display-add-backlight-driver-and-overlay.patch @@ -0,0 +1,164 @@ +From ae5ae9278768c3d096910705bfa9af85da20a8cf Mon Sep 17 00:00:00 2001 +From: P33M <P33M@github.com> +Date: Wed, 21 Oct 2015 14:55:21 +0100 +Subject: [PATCH] rpi_display: add backlight driver and overlay + +Add a mailbox-driven backlight controller for the Raspberry Pi DSI +touchscreen display. Requires updated GPU firmware to recognise the +mailbox request. + +Signed-off-by: Gordon Hollingworth <gordon@raspberrypi.org> +--- + drivers/video/backlight/Kconfig | 6 ++ + drivers/video/backlight/Makefile | 1 + + drivers/video/backlight/rpi_backlight.c | 119 ++++++++++++++++++++++++++++++++ + 3 files changed, 126 insertions(+) + create mode 100644 drivers/video/backlight/rpi_backlight.c + +--- a/drivers/video/backlight/Kconfig ++++ b/drivers/video/backlight/Kconfig +@@ -265,6 +265,12 @@ config BACKLIGHT_PWM + If you have a LCD backlight adjustable by PWM, say Y to enable + this driver. + ++config BACKLIGHT_RPI ++ tristate "Raspberry Pi display firmware driven backlight" ++ help ++ If you have the Raspberry Pi DSI touchscreen display, say Y to ++ enable the mailbox-controlled backlight driver. ++ + config BACKLIGHT_DA903X + tristate "Backlight Driver for DA9030/DA9034 using WLED" + depends on PMIC_DA903X +--- a/drivers/video/backlight/Makefile ++++ b/drivers/video/backlight/Makefile +@@ -50,6 +50,7 @@ obj-$(CONFIG_BACKLIGHT_PANDORA) += pand + obj-$(CONFIG_BACKLIGHT_PCF50633) += pcf50633-backlight.o + obj-$(CONFIG_BACKLIGHT_PM8941_WLED) += pm8941-wled.o + obj-$(CONFIG_BACKLIGHT_PWM) += pwm_bl.o ++obj-$(CONFIG_BACKLIGHT_RPI) += rpi_backlight.o + obj-$(CONFIG_BACKLIGHT_SAHARA) += kb3886_bl.o + obj-$(CONFIG_BACKLIGHT_SKY81452) += sky81452-backlight.o + obj-$(CONFIG_BACKLIGHT_TOSA) += tosa_bl.o +--- /dev/null ++++ b/drivers/video/backlight/rpi_backlight.c +@@ -0,0 +1,119 @@ ++/* ++ * rpi_bl.c - Backlight controller through VPU ++ * ++ * This program is free software; you can redistribute it and/or modify ++ * it under the terms of the GNU General Public License version 2 as ++ * published by the Free Software Foundation. ++ */ ++ ++#include <linux/backlight.h> ++#include <linux/err.h> ++#include <linux/fb.h> ++#include <linux/gpio.h> ++#include <linux/init.h> ++#include <linux/kernel.h> ++#include <linux/module.h> ++#include <linux/of.h> ++#include <linux/of_gpio.h> ++#include <linux/platform_device.h> ++#include <linux/slab.h> ++#include <soc/bcm2835/raspberrypi-firmware.h> ++ ++struct rpi_backlight { ++ struct device *dev; ++ struct device *fbdev; ++ struct rpi_firmware *fw; ++}; ++ ++static int rpi_backlight_update_status(struct backlight_device *bl) ++{ ++ struct rpi_backlight *gbl = bl_get_data(bl); ++ int brightness = bl->props.brightness; ++ int ret; ++ ++ if (bl->props.power != FB_BLANK_UNBLANK || ++ bl->props.fb_blank != FB_BLANK_UNBLANK || ++ bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) ++ brightness = 0; ++ ++ ret = rpi_firmware_property(gbl->fw, ++ RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT, ++ &brightness, sizeof(brightness)); ++ if (ret) { ++ dev_err(gbl->dev, "Failed to set brightness\n"); ++ return ret; ++ } ++ ++ if (brightness < 0) { ++ dev_err(gbl->dev, "Backlight change failed\n"); ++ return -EAGAIN; ++ } ++ ++ return 0; ++} ++ ++static const struct backlight_ops rpi_backlight_ops = { ++ .options = BL_CORE_SUSPENDRESUME, ++ .update_status = rpi_backlight_update_status, ++}; ++ ++static int rpi_backlight_probe(struct platform_device *pdev) ++{ ++ struct backlight_properties props; ++ struct backlight_device *bl; ++ struct rpi_backlight *gbl; ++ struct device_node *fw_node; ++ ++ gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL); ++ if (gbl == NULL) ++ return -ENOMEM; ++ ++ gbl->dev = &pdev->dev; ++ ++ fw_node = of_parse_phandle(pdev->dev.of_node, "firmware", 0); ++ if (!fw_node) { ++ dev_err(&pdev->dev, "Missing firmware node\n"); ++ return -ENOENT; ++ } ++ ++ gbl->fw = rpi_firmware_get(fw_node); ++ if (!gbl->fw) ++ return -EPROBE_DEFER; ++ ++ memset(&props, 0, sizeof(props)); ++ props.type = BACKLIGHT_RAW; ++ props.max_brightness = 255; ++ bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev), ++ &pdev->dev, gbl, &rpi_backlight_ops, ++ &props); ++ if (IS_ERR(bl)) { ++ dev_err(&pdev->dev, "failed to register backlight\n"); ++ return PTR_ERR(bl); ++ } ++ ++ bl->props.brightness = 255; ++ backlight_update_status(bl); ++ ++ platform_set_drvdata(pdev, bl); ++ return 0; ++} ++ ++static const struct of_device_id rpi_backlight_of_match[] = { ++ { .compatible = "raspberrypi,rpi-backlight" }, ++ { /* sentinel */ } ++}; ++MODULE_DEVICE_TABLE(of, rpi_backlight_of_match); ++ ++static struct platform_driver rpi_backlight_driver = { ++ .driver = { ++ .name = "rpi-backlight", ++ .of_match_table = of_match_ptr(rpi_backlight_of_match), ++ }, ++ .probe = rpi_backlight_probe, ++}; ++ ++module_platform_driver(rpi_backlight_driver); ++ ++MODULE_AUTHOR("Gordon Hollingworth <gordon@raspberrypi.org>"); ++MODULE_DESCRIPTION("Raspberry Pi mailbox based Backlight Driver"); ++MODULE_LICENSE("GPL"); |