[PATCH 4/8] video: atmel_lcdfb: add device tree suport
Nicolas Ferre
nicolas.ferre at atmel.com
Tue Apr 16 23:42:36 EST 2013
On 04/11/2013 05:00 PM, Jean-Christophe PLAGNIOL-VILLARD :
> get display timings from device tree
> Use videomode helpers to get display timings and configurations from
> device tree
2 sentences? Simply elaborate the 2nd one and it will be good.
> 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
Why lcdc? I would have preferred atmel,lcdfb, like the driver's name: it
is even more self-explanatory...
> @@ -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):
Can you please point somewhere to the documentation:
Documentation/devicetree/bindings/video/display-timing.txt
> + - atmel,dmacon: dma controler configuration
Typo: controller.
> + - atmel,lcdcon2: lcd controler configuration
Ditto
> + - atmel,guard-time: lcd guard time (Delay in frame periods)
periods -> period, no?
> + - 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"
Is it a sting, or a number (as seen below)? If it is a number, please
tell how to choose the index.
> + - 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>
As said in patch 1/8, this one belongs to this 4/8 patch.
> +#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;
Please split it in 2 steps, otherwise the day that the drivers doesn't
find the device in dt_ids table, it hangs here with an Oops.
> +
> + 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");
No, wrong error message.
> + 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");
> +
> + timings = of_get_display_timings(display_np);
> + if (!timings) {
> + dev_err(dev, "failed to get display timings\n");
> + goto put_display_node;
> + }
> +
> + timings_np = of_find_node_by_name(display_np, "display-timings");
> + if (!timings_np) {
> + dev_err(dev, "failed to find display-timings node\n");
> + goto put_display_node;
> + }
> +
> + for (i = 0; i < of_get_child_count(timings_np); i++) {
> + struct videomode vm;
> + struct fb_videomode fb_vm;
> +
> + ret = videomode_from_timing(timings, &vm, i);
> + if (ret < 0)
> + goto put_timings_node;
> + ret = fb_videomode_from_videomode(&vm, &fb_vm);
> + if (ret < 0)
> + goto put_timings_node;
> +
> + fb_add_videomode(&fb_vm, &info->modelist);
> + }
> +
> + return 0;
> +
> +put_timings_node:
> + of_node_put(timings_np);
> +put_display_node:
> + of_node_put(display_np);
> + return ret;
> +}
> +#else
> +static int atmel_lcdfb_of_init(struct atmel_lcdfb_info *sinfo)
> +{
> + return 0;
> +}
> +#endif
>
> static int __init atmel_lcdfb_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> struct fb_info *info;
> struct atmel_lcdfb_info *sinfo;
> - struct atmel_lcdfb_pdata *pdata;
> - struct fb_videomode fbmode;
> + struct atmel_lcdfb_pdata *pdata = NULL;
> struct resource *regs = NULL;
> struct resource *map = NULL;
> + struct fb_modelist *modelist;
> int ret;
>
> dev_dbg(dev, "%s BEGIN\n", __func__);
> @@ -967,17 +1149,35 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
> }
>
> sinfo = info->par;
> + sinfo->pdev = pdev;
> + sinfo->info = info;
> +
> + INIT_LIST_HEAD(&info->modelist);
>
> - if (dev->platform_data) {
> - pdata = (struct atmel_lcdfb_pdata *)dev->platform_data;
> + if (pdev->dev.of_node) {
> + ret = atmel_lcdfb_of_init(sinfo);
> + if (ret)
> + goto free_info;
> + } else if (dev->platform_data) {
> + struct fb_monspecs *monspecs;
> + int i;
> +
> + pdata = dev->platform_data;
> + monspecs = pdata->default_monspecs;
> sinfo->pdata = *pdata;
> +
> + for (i = 0; i < monspecs->modedb_len; i++)
> + fb_add_videomode(&monspecs->modedb[i], &info->modelist);
> +
> + sinfo->config = atmel_lcdfb_get_config(pdev);
> +
> + info->var.bits_per_pixel = pdata->default_bpp ? pdata->default_bpp : 16;
> + memcpy(&info->monspecs, pdata->default_monspecs, sizeof(info->monspecs));
> } else {
> dev_err(dev, "cannot get default configuration\n");
> goto free_info;
> }
> - sinfo->info = info;
> - sinfo->pdev = pdev;
> - sinfo->config = atmel_lcdfb_get_config(pdev);
> +
> if (!sinfo->config)
> goto free_info;
>
> @@ -986,7 +1186,6 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
> info->pseudo_palette = sinfo->pseudo_palette;
> info->fbops = &atmel_lcdfb_ops;
>
> - memcpy(&info->monspecs, pdata->default_monspecs, sizeof(info->monspecs));
> info->fix = atmel_lcdfb_fix;
>
> /* Enable LCDC Clocks */
> @@ -1002,14 +1201,11 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
> }
> atmel_lcdfb_start_clock(sinfo);
>
> - ret = fb_find_mode(&info->var, info, NULL, info->monspecs.modedb,
> - info->monspecs.modedb_len, info->monspecs.modedb,
> - pdata->default_bpp);
> - if (!ret) {
> - dev_err(dev, "no suitable video mode found\n");
> - goto stop_clk;
> - }
> + modelist = list_first_entry(&info->modelist,
> + struct fb_modelist, list);
> + fb_videomode_to_var(&info->var, &modelist->mode);
>
> + atmel_lcdfb_check_var(&info->var, info);
>
> regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!regs) {
> @@ -1093,18 +1289,6 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
> goto unregister_irqs;
> }
>
> - /*
> - * This makes sure that our colour bitfield
> - * descriptors are correctly initialised.
> - */
> - atmel_lcdfb_check_var(&info->var, info);
> -
> - ret = fb_set_var(info, &info->var);
> - if (ret) {
> - dev_warn(dev, "unable to set display parameters\n");
> - goto free_cmap;
> - }
> -
> dev_set_drvdata(dev, info);
>
> /*
> @@ -1116,10 +1300,6 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
> goto reset_drvdata;
> }
>
> - /* add selected videomode to modelist */
> - fb_var_to_videomode(&fbmode, &info->var);
> - fb_add_videomode(&fbmode, &info->modelist);
> -
> /* Power up the LCDC screen */
> atmel_lcdfb_power_control(sinfo, 1);
>
> @@ -1130,7 +1310,6 @@ static int __init atmel_lcdfb_probe(struct platform_device *pdev)
>
> reset_drvdata:
> dev_set_drvdata(dev, NULL);
> -free_cmap:
> fb_dealloc_cmap(&info->cmap);
> unregister_irqs:
> cancel_work_sync(&sinfo->task);
> @@ -1249,6 +1428,7 @@ static struct platform_driver atmel_lcdfb_driver = {
> .driver = {
> .name = "atmel_lcdfb",
> .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(atmel_lcdfb_dt_ids),
> },
> };
>
>
--
Nicolas Ferre
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