From 574dfed6fa4e845eab5632d5f956e7ec879d6416 Mon Sep 17 00:00:00 2001 From: P33M Date: Wed, 21 Oct 2015 14:55:21 +0100 Subject: [PATCH 089/454] 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 --- 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 @@ -51,6 +51,7 @@ 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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 "); +MODULE_DESCRIPTION("Raspberry Pi mailbox based Backlight Driver"); +MODULE_LICENSE("GPL");