[PATCH 4/8] video: atmel_lcdfb: add device tree suport
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Tue Apr 16 09:44:04 EDT 2013
On 15:42 Tue 16 Apr , Nicolas Ferre wrote:
> 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...
we do not describe drivers but IP
>
> > @@ -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?
no it's periods even in the datasheet
>
> > + - 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.
String
>
>
> > + - 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.
no as you will never end here in this case
>
> > +
> > + 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
More information about the linux-arm-kernel
mailing list