[PATCH 4/8] video: atmel_lcdfb: add device tree suport
Nicolas Ferre
nicolas.ferre at atmel.com
Tue Apr 16 11:43:18 EDT 2013
On 04/16/2013 03:44 PM, Jean-Christophe PLAGNIOL-VILLARD :
> 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
fine, but in
static const struct platform_device_id atmel_lcdfb_devtypes, we use
"xxx-lcdfb" type...
>>
>>> @@ -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
Okay: so tell it in the description and correct the example below.
>>> + - 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>;
Here ----------------------------------^^^^
>>> +
>>> + 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
Ok, I see.
>>
>>> +
>>> + 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
>
>
--
Nicolas Ferre
More information about the linux-arm-kernel
mailing list