Re: [PATCH 4/8] video: atmel_lcdfb: add device tree suport

get display timings from device tree
Use videomode helpers to get display timings and configurations from
device tree

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <redacted>
Cc: linux-fbdev@vger.kernel.org
Cc: Nicolas Ferre <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
 .../devicetree/bindings/video/atmel,lcdc.txt       |   75 ++++++
 drivers/video/Kconfig                              |    2 +
 drivers/video/atmel_lcdfb.c                        |  244 +++++++++++++++++---
 3 files changed, 289 insertions(+), 32 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/video/atmel,lcdc.txt

diff --git a/Documentation/devicetree/bindings/video/atmel,lcdc.txt b/Documentation/devicetree/bindings/video/atmel,lcdc.txt
new file mode 100644
index 0000000..1ec175e
--- /dev/null
+++ b/Documentation/devicetree/bindings/video/atmel,lcdc.txt

@@ -0,0 +1,75 @@
+Atmel LCDC Framebuffer
+-----------------------------------------------------
+
+Required properties:
+- compatible :
+       "atmel,at91sam9261-lcdc" ,
+       "atmel,at91sam9263-lcdc" ,
+       "atmel,at91sam9g10-lcdc" ,
+       "atmel,at91sam9g45-lcdc" ,
+       "atmel,at91sam9g45es-lcdc" ,
+       "atmel,at91sam9rl-lcdc" ,
+       "atmel,at32ap-lcdc"
+- reg : Should contain 1 register ranges(address and length)
+- interrupts : framebuffer controller interrupt
+- display: a phandle pointing to the display node
+
+Required nodes:
+- display: a display node is required to initialize the lcd panel
+       This should be in the board dts.
+- default-mode: a videomode within the display with timing parameters
+       as specified below.
+
+Example:
+
+       fb0: fb@0x00500000 {
+               compatible = "atmel,at91sam9g45-lcdc";
+               reg = <0x00500000 0x1000>;
+               interrupts = <23 3 0>;
+               pinctrl-names = "default";
+               pinctrl-0 = <&pinctrl_fb>;
+               display = <&display0>;
+               status = "okay";
+               #address-cells = <1>;
+               #size-cells = <1>;
+
+       };
+
+Atmel LCDC Display
+-----------------------------------------------------
+Required properties (as per of_videomode_helper):
+
+ - atmel,dmacon: dma controler configuration
+ - atmel,lcdcon2: lcd controler configuration
+ - atmel,guard-time: lcd guard time (Delay in frame periods)
+ - bits-per-pixel: lcd panel bit-depth.
+
+Optional properties (as per of_videomode_helper):
+ - atmel,lcdcon-backlight: enable backlight
+ - atmel,lcd-wiring-mode: lcd wiring mode "RGB" or "BRG"
+ - atmel,power-control-gpio: gpio to power on or off the LCD (as many as needed)

+
+Example:
+       display0: display {
+               bits-per-pixel = <32>;
+               atmel,lcdcon-backlight;
+               atmel,dmacon = <0x1>;
+               atmel,lcdcon2 = <0x80008002>;
+               atmel,guard-time = <9>;
+               atmel,lcd-wiring-mode = <1>;
+
+               display-timings {
+                       native-mode = <&timing0>;
+                       timing0: timing0 {
+                               clock-frequency = <9000000>;
+                               hactive = <480>;
+                               vactive = <272>;
+                               hback-porch = <1>;
+                               hfront-porch = <1>;
+                               vback-porch = <40>;
+                               vfront-porch = <1>;
+                               hsync-len = <45>;
+                               vsync-len = <1>;
+                       };
+               };
+       };

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 4c1546f..0687482 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig

@@ -1018,6 +1018,8 @@ config FB_ATMEL
        select FB_CFB_FILLRECT
        select FB_CFB_COPYAREA
        select FB_CFB_IMAGEBLIT
+       select FB_MODE_HELPERS
+       select OF_VIDEOMODE
        help
          This enables support for the AT91/AT32 LCD Controller.

diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index f67e226..4a31570 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c

@@ -20,7 +20,11 @@
 #include <linux/gfp.h>
 #include <linux/module.h>
 #include <linux/platform_data/atmel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <video/of_display_timing.h>
+#include <video/videomode.h>

 #include <mach/cpu.h>
 #include <asm/gpio.h>

@@ -59,6 +63,13 @@ struct atmel_lcdfb_info {
        struct atmel_lcdfb_config *config;
 };

+struct atmel_lcdfb_power_ctrl_gpio {
+       int gpio;
+       int active_low;
+
+       struct list_head list;
+};
+
 #define lcdc_readl(sinfo, reg)         __raw_readl((sinfo)->mmio+(reg))
 #define lcdc_writel(sinfo, reg, val)   __raw_writel((val), (sinfo)->mmio+(reg))

@@ -945,16 +956,187 @@ static void atmel_lcdfb_stop_clock(struct atmel_lcdfb_info *sinfo)
        clk_disable(sinfo->lcdc_clk);
 }

+#ifdef CONFIG_OF
+static const struct of_device_id atmel_lcdfb_dt_ids[] = {
+       { .compatible = "atmel,at91sam9261-lcdc" , .data = &at91sam9261_config, },
+       { .compatible = "atmel,at91sam9263-lcdc" , .data = &at91sam9263_config, },
+       { .compatible = "atmel,at91sam9g10-lcdc" , .data = &at91sam9g10_config, },
+       { .compatible = "atmel,at91sam9g45-lcdc" , .data = &at91sam9g45_config, },
+       { .compatible = "atmel,at91sam9g45es-lcdc" , .data = &at91sam9g45es_config, },
+       { .compatible = "atmel,at91sam9rl-lcdc" , .data = &at91sam9rl_config, },
+       { .compatible = "atmel,at32ap-lcdc" , .data = &at32ap_config, },
+       { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_lcdfb_dt_ids);
+
+static const char *atmel_lcdfb_wiring_modes[] = {
+       [ATMEL_LCDC_WIRING_BGR] = "BRG",
+       [ATMEL_LCDC_WIRING_RGB] = "RGB",
+};
+
+const int atmel_lcdfb_get_of_wiring_modes(struct device_node *np)
+{
+       const char *mode;
+       int err, i;
+
+       err = of_property_read_string(np, "atmel,lcd-wiring-mode", &mode);
+       if (err < 0)
+               return ATMEL_LCDC_WIRING_BGR;
+
+       for (i = 0; i < ARRAY_SIZE(atmel_lcdfb_wiring_modes); i++)
+               if (!strcasecmp(mode, atmel_lcdfb_wiring_modes[i]))
+                       return i;
+
+       return -ENODEV;
+}
+
+static void atmel_lcdfb_power_control_gpio(struct atmel_lcdfb_pdata *pdata, int on)
+{
+       struct atmel_lcdfb_power_ctrl_gpio *og;
+
+       list_for_each_entry(og, &pdata->pwr_gpios, list)
+               gpio_set_value(og->gpio, on);
+}
+
+static int atmel_lcdfb_of_init(struct atmel_lcdfb_info *sinfo)
+{
+       struct fb_info *info = sinfo->info;
+       struct atmel_lcdfb_pdata *pdata = &sinfo->pdata;
+       struct fb_var_screeninfo *var = &info->var;
+       struct device *dev = &sinfo->pdev->dev;
+       struct device_node *np Þv->of_node;
+       struct device_node *display_np;
+       struct device_node *timings_np;
+       struct display_timings *timings;
+       enum of_gpio_flags flags;
+       struct atmel_lcdfb_power_ctrl_gpio *og;
+       bool is_gpio_power = false;
+       int ret = -ENOENT;
+       int i, gpio;
+
+       sinfo->config = (struct atmel_lcdfb_config*)
+               of_match_device(atmel_lcdfb_dt_ids, dev)->data;
+
+       display_np = of_parse_phandle(np, "display", 0);
+       if (!display_np) {
+               dev_err(dev, "failed to find display phandle\n");
+               return -ENOENT;
+       }
+
+       ret = of_property_read_u32(display_np, "bits-per-pixel", &var->bits_per_pixel);
+       if (ret < 0) {
+               dev_err(dev, "failed to get property bits-per-pixel\n");
+               goto put_display_node;
+       }
+
+       ret = of_property_read_u32(display_np, "atmel,guard-time", &pdata->guard_time);
+       if (ret < 0) {
+               dev_err(dev, "failed to get property atmel,guard-time\n");
+               goto put_display_node;
+       }
+
+       ret = of_property_read_u32(display_np, "atmel,lcdcon2", &pdata->default_lcdcon2);
+       if (ret < 0) {
+               dev_err(dev, "failed to get property atmel,lcdcon2\n");
+               goto put_display_node;
+       }
+
+       ret = of_property_read_u32(display_np, "atmel,dmacon", &pdata->default_dmacon);
+       if (ret < 0) {
+               dev_err(dev, "failed to get property bits-per-pixel\n");
+               goto put_display_node;
+       }
+
+       ret = -ENOMEM;
+       for (i = 0; i < of_gpio_named_count(display_np, "atmel,power-control-gpio"); i++) {
+               gpio = of_get_named_gpio_flags(display_np, "atmel,power-control-gpio",
+                                              i, &flags);
+               if (gpio < 0)
+                       continue;
+
+               og = devm_kzalloc(dev, sizeof(*og), GFP_KERNEL);
+               if (!og)
+                       goto put_display_node;
+
+               og->gpio = gpio;
+               og->active_low = flags & OF_GPIO_ACTIVE_LOW;
+               is_gpio_power = true;
+               ret = devm_gpio_request(dev, gpio, "lcd-power-control-gpio");
+               if (ret) {
+                       dev_err(dev, "request gpio %d failed\n", gpio);
+                       goto put_display_node;
+               }
+
+               ret = gpio_direction_output(gpio, og->active_low);
+               if (ret) {
+                       dev_err(dev, "set direction output gpio %d failed\n", gpio);
+                       goto put_display_node;
+               }
+       }
+
+       if (is_gpio_power)
+               pdata->atmel_lcdfb_power_control = atmel_lcdfb_power_control_gpio;
+
+       ret = atmel_lcdfb_get_of_wiring_modes(display_np);
+       if (ret < 0) {
+               dev_err(dev, "invalid atmel,lcd-wiring-mode\n");
+               goto put_display_node;
+       }
+       pdata->lcd_wiring_mode = ret;
+
+       pdata->lcdcon_is_backlight = of_property_read_bool(display_np, "atmel,lcdcon-backlight");