[PATCH 4/8] video: atmel_lcdfb: add device tree suport
Richard Genoud
richard.genoud at gmail.com
Wed May 29 11:01:58 EDT 2013
2013/4/11 Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>:
> 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 <plagnioj at jcrosoft.com>
> Cc: linux-fbdev at vger.kernel.org
> Cc: Nicolas Ferre <nicolas.ferre at atmel.com>
> Cc: Andrew Morton <akpm at 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 at 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)
still on lcdcon_pol_negative, we can add something like that:
- atmel,lcdcon-pwm-pulse-low: Output PWM pulses are low level (high
level if not set)
> +
> +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 =dev->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");
and here, something like:
pdata->lcdcon_pol_negative = of_property_read_bool(display_np,
"atmel,lcdcon-pwm-pulse-low");
would be nice
Regards,
Richard.
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