target/linux/brcm2708/patches-4.4/0088-rpi_display-add-backlight-driver-and-overlay.patch

   1 From 356081aede8e5bd1b9503c4510e1d4fc0d85b026 Mon Sep 17 00:00:00 2001
   2 From: P33M <P33M@github.com>
   3 Date: Wed, 21 Oct 2015 14:55:21 +0100
   4 Subject: [PATCH 088/127] rpi_display: add backlight driver and overlay
   5
   6 Add a mailbox-driven backlight controller for the Raspberry Pi DSI
   7 touchscreen display. Requires updated GPU firmware to recognise the
   8 mailbox request.
   9
  10 Signed-off-by: Gordon Hollingworth <gordon@raspberrypi.org>
  11 ---
  12  arch/arm/boot/dts/overlays/Makefile                |   1 +
  13  arch/arm/boot/dts/overlays/README                  |   6 ++
  14  .../boot/dts/overlays/rpi-backlight-overlay.dts    |  21 ++++
  15  arch/arm/configs/bcm2709_defconfig                 |   1 +
  16  arch/arm/configs/bcmrpi_defconfig                  |   1 +
  17  drivers/video/backlight/Kconfig                    |   6 ++
  18  drivers/video/backlight/Makefile                   |   1 +
  19  drivers/video/backlight/rpi_backlight.c            | 119 +++++++++++++++++++++
  20  include/soc/bcm2835/raspberrypi-firmware.h         |   1 +
  21  9 files changed, 157 insertions(+)
  22  create mode 100644 arch/arm/boot/dts/overlays/rpi-backlight-overlay.dts
  23  create mode 100644 drivers/video/backlight/rpi_backlight.c
  24
  25 --- a/arch/arm/boot/dts/overlays/Makefile
  26 +++ b/arch/arm/boot/dts/overlays/Makefile
  27 @@ -38,6 +38,7 @@ dtb-$(RPI_DT_OVERLAYS) += pps-gpio-overl
  28  dtb-$(RPI_DT_OVERLAYS) += pwm-overlay.dtb
  29  dtb-$(RPI_DT_OVERLAYS) += pwm-2chan-overlay.dtb
  30  dtb-$(RPI_DT_OVERLAYS) += raspidac3-overlay.dtb
  31 +dtb-$(RPI_DT_OVERLAYS) += rpi-backlight-overlay.dtb
  32  dtb-$(RPI_DT_OVERLAYS) += rpi-dac-overlay.dtb
  33  dtb-$(RPI_DT_OVERLAYS) += rpi-display-overlay.dtb
  34  dtb-$(RPI_DT_OVERLAYS) += rpi-ft5406-overlay.dtb
  35 --- a/arch/arm/boot/dts/overlays/README
  36 +++ b/arch/arm/boot/dts/overlays/README
  37 @@ -462,6 +462,12 @@ Load:   dtoverlay=raspidac3
  38  Params: <None>
  39
  40
  41 +Name:   rpi-backlight
  42 +Info:   Raspberry Pi official display backlight driver
  43 +Load:   dtoverlay=rpi-backlight
  44 +Params: <None>
  45 +
  46 +
  47  Name:   rpi-dac
  48  Info:   Configures the RPi DAC audio card
  49  Load:   dtoverlay=rpi-dac
  50 --- /dev/null
  51 +++ b/arch/arm/boot/dts/overlays/rpi-backlight-overlay.dts
  52 @@ -0,0 +1,21 @@
  53 +/*
  54 + * Devicetree overlay for mailbox-driven Raspberry Pi DSI Display
  55 + * backlight controller
  56 + */
  57 +/dts-v1/;
  58 +/plugin/;
  59 +
  60 +/ {
  61 +       compatible = "brcm,bcm2708";
  62 +
  63 +       fragment@0 {
  64 +               target-path = "/";
  65 +               __overlay__ {
  66 +                       rpi_backlight: rpi_backlight {
  67 +                               compatible = "raspberrypi,rpi-backlight";
  68 +                               firmware = <&firmware>;
  69 +                               status = "okay";
  70 +                       };
  71 +               };
  72 +       };
  73 +};
  74 --- a/arch/arm/configs/bcm2709_defconfig
  75 +++ b/arch/arm/configs/bcm2709_defconfig
  76 @@ -808,6 +808,7 @@ CONFIG_FB_UDL=m
  77  CONFIG_FB_SSD1307=m
  78  CONFIG_FB_RPISENSE=m
  79  # CONFIG_BACKLIGHT_GENERIC is not set
  80 +CONFIG_BACKLIGHT_RPI=m
  81  CONFIG_BACKLIGHT_GPIO=m
  82  CONFIG_FRAMEBUFFER_CONSOLE=y
  83  CONFIG_LOGO=y
  84 --- a/arch/arm/configs/bcmrpi_defconfig
  85 +++ b/arch/arm/configs/bcmrpi_defconfig
  86 @@ -801,6 +801,7 @@ CONFIG_FB_UDL=m
  87  CONFIG_FB_SSD1307=m
  88  CONFIG_FB_RPISENSE=m
  89  # CONFIG_BACKLIGHT_GENERIC is not set
  90 +CONFIG_BACKLIGHT_RPI=m
  91  CONFIG_BACKLIGHT_GPIO=m
  92  CONFIG_FRAMEBUFFER_CONSOLE=y
  93  CONFIG_LOGO=y
  94 --- a/drivers/video/backlight/Kconfig
  95 +++ b/drivers/video/backlight/Kconfig
  96 @@ -265,6 +265,12 @@ config BACKLIGHT_PWM
  97           If you have a LCD backlight adjustable by PWM, say Y to enable
  98           this driver.
  99
 100 +config BACKLIGHT_RPI
 101 +       tristate "Raspberry Pi display firmware driven backlight"
 102 +       help
 103 +         If you have the Raspberry Pi DSI touchscreen display, say Y to
 104 +         enable the mailbox-controlled backlight driver.
 105 +
 106  config BACKLIGHT_DA903X
 107         tristate "Backlight Driver for DA9030/DA9034 using WLED"
 108         depends on PMIC_DA903X
 109 --- a/drivers/video/backlight/Makefile
 110 +++ b/drivers/video/backlight/Makefile
 111 @@ -50,6 +50,7 @@ obj-$(CONFIG_BACKLIGHT_PANDORA)               += pand
 112  obj-$(CONFIG_BACKLIGHT_PCF50633)       += pcf50633-backlight.o
 113  obj-$(CONFIG_BACKLIGHT_PM8941_WLED)    += pm8941-wled.o
 114  obj-$(CONFIG_BACKLIGHT_PWM)            += pwm_bl.o
 115 +obj-$(CONFIG_BACKLIGHT_RPI)                    += rpi_backlight.o
 116  obj-$(CONFIG_BACKLIGHT_SAHARA)         += kb3886_bl.o
 117  obj-$(CONFIG_BACKLIGHT_SKY81452)       += sky81452-backlight.o
 118  obj-$(CONFIG_BACKLIGHT_TOSA)           += tosa_bl.o
 119 --- /dev/null
 120 +++ b/drivers/video/backlight/rpi_backlight.c
 121 @@ -0,0 +1,119 @@
 122 +/*
 123 + * rpi_bl.c - Backlight controller through VPU
 124 + *
 125 + * This program is free software; you can redistribute it and/or modify
 126 + * it under the terms of the GNU General Public License version 2 as
 127 + * published by the Free Software Foundation.
 128 + */
 129 +
 130 +#include <linux/backlight.h>
 131 +#include <linux/err.h>
 132 +#include <linux/fb.h>
 133 +#include <linux/gpio.h>
 134 +#include <linux/init.h>
 135 +#include <linux/kernel.h>
 136 +#include <linux/module.h>
 137 +#include <linux/of.h>
 138 +#include <linux/of_gpio.h>
 139 +#include <linux/platform_device.h>
 140 +#include <linux/slab.h>
 141 +#include <soc/bcm2835/raspberrypi-firmware.h>
 142 +
 143 +struct rpi_backlight {
 144 +       struct device *dev;
 145 +       struct device *fbdev;
 146 +       struct rpi_firmware *fw;
 147 +};
 148 +
 149 +static int rpi_backlight_update_status(struct backlight_device *bl)
 150 +{
 151 +       struct rpi_backlight *gbl = bl_get_data(bl);
 152 +       int brightness = bl->props.brightness;
 153 +       int ret;
 154 +
 155 +       if (bl->props.power != FB_BLANK_UNBLANK ||
 156 +           bl->props.fb_blank != FB_BLANK_UNBLANK ||
 157 +           bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
 158 +               brightness = 0;
 159 +
 160 +       ret = rpi_firmware_property(gbl->fw,
 161 +                       RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT,
 162 +                       &brightness, sizeof(brightness));
 163 +       if (ret) {
 164 +               dev_err(gbl->dev, "Failed to set brightness\n");
 165 +               return ret;
 166 +       }
 167 +
 168 +       if (brightness < 0) {
 169 +               dev_err(gbl->dev, "Backlight change failed\n");
 170 +               return -EAGAIN;
 171 +       }
 172 +
 173 +       return 0;
 174 +}
 175 +
 176 +static const struct backlight_ops rpi_backlight_ops = {
 177 +       .options        = BL_CORE_SUSPENDRESUME,
 178 +       .update_status  = rpi_backlight_update_status,
 179 +};
 180 +
 181 +static int rpi_backlight_probe(struct platform_device *pdev)
 182 +{
 183 +       struct backlight_properties props;
 184 +       struct backlight_device *bl;
 185 +       struct rpi_backlight *gbl;
 186 +       struct device_node *fw_node;
 187 +
 188 +       gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL);
 189 +       if (gbl == NULL)
 190 +               return -ENOMEM;
 191 +
 192 +       gbl->dev = &pdev->dev;
 193 +
 194 +       fw_node = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
 195 +       if (!fw_node) {
 196 +               dev_err(&pdev->dev, "Missing firmware node\n");
 197 +               return -ENOENT;
 198 +       }
 199 +
 200 +       gbl->fw = rpi_firmware_get(fw_node);
 201 +       if (!gbl->fw)
 202 +               return -EPROBE_DEFER;
 203 +
 204 +       memset(&props, 0, sizeof(props));
 205 +       props.type = BACKLIGHT_RAW;
 206 +       props.max_brightness = 255;
 207 +       bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev),
 208 +                                       &pdev->dev, gbl, &rpi_backlight_ops,
 209 +                                       &props);
 210 +       if (IS_ERR(bl)) {
 211 +               dev_err(&pdev->dev, "failed to register backlight\n");
 212 +               return PTR_ERR(bl);
 213 +       }
 214 +
 215 +       bl->props.brightness = 255;
 216 +       backlight_update_status(bl);
 217 +
 218 +       platform_set_drvdata(pdev, bl);
 219 +       return 0;
 220 +}
 221 +
 222 +static const struct of_device_id rpi_backlight_of_match[] = {
 223 +       { .compatible = "raspberrypi,rpi-backlight" },
 224 +       { /* sentinel */ }
 225 +};
 226 +MODULE_DEVICE_TABLE(of, rpi_backlight_of_match);
 227 +
 228 +static struct platform_driver rpi_backlight_driver = {
 229 +       .driver         = {
 230 +               .name           = "rpi-backlight",
 231 +               .of_match_table = of_match_ptr(rpi_backlight_of_match),
 232 +       },
 233 +       .probe          = rpi_backlight_probe,
 234 +};
 235 +
 236 +module_platform_driver(rpi_backlight_driver);
 237 +
 238 +MODULE_AUTHOR("Gordon Hollingworth <gordon@raspberrypi.org>");
 239 +MODULE_DESCRIPTION("Raspberry Pi mailbox based Backlight Driver");
 240 +MODULE_LICENSE("GPL");
 241 --- a/include/soc/bcm2835/raspberrypi-firmware.h
 242 +++ b/include/soc/bcm2835/raspberrypi-firmware.h
 243 @@ -112,6 +112,7 @@ enum rpi_firmware_property_tag {
 244         RPI_FIRMWARE_FRAMEBUFFER_SET_OVERSCAN =               0x0004800a,
 245         RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE =                0x0004800b,
 246         RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC =                  0x0004800e,
 247 +       RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT =              0x0004800f,
 248
 249         RPI_FIRMWARE_VCHIQ_INIT =                             0x00048010,
 250