[4/4] drm/panel/ili9341: Support DPI panels

[Noralf Trønnes]

Den 01.08.2019 21.10, skrev David Lechner:
> On 8/1/19 8:52 AM, Noralf Trønnes wrote:
>> Add support for panels that use the DPI interface.
>> ILI9341 has onboard RAM so the assumption made here is that all such
>> panels support pixel upload over DBI.
>>
>> The presence/absense of the Device Tree 'port' node decides which
>> interface is used for pixel transfer.
>>
>> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
>> ---
>>   drivers/gpu/drm/panel/panel-ilitek-ili9341.c | 56 ++++++++++++++++----
>>   1 file changed, 45 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
>> b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
>> index f6082fa2a389..7cbfd739c7fd 100644
>> --- a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
>> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
>> @@ -11,6 +11,7 @@
>>   #include <linux/gpio/consumer.h>
>>   #include <linux/module.h>
>>   #include <linux/of_device.h>
>> +#include <linux/of_graph.h>
>>   #include <linux/pm.h>
>>   #include <linux/property.h>
>>   #include <linux/regulator/consumer.h>
>> @@ -53,11 +54,13 @@
>>   struct ili9341_config {
>>       const struct drm_panel_funcs *funcs;
>>       const struct drm_display_mode *mode;
>> +    bool no_dpi;
> 
> Can we invert this to use positive logic? i.e. use_dpi instead of
> no_dpi.
> 

This is a capability flag. I could call it has_dpi and add a comment
about what it does.

Noralf.

>>   };
>>     struct ili9341 {
>>       struct mipi_dbi_dev dbidev; /* This must be the first entry */
>>       struct drm_panel panel;
>> +    bool use_dpi;
>>       struct regulator *regulator;
>>       struct backlight_device *backlight;
>>       const struct ili9341_config *conf;
>> @@ -174,6 +177,7 @@ static const struct drm_display_mode
>> yx240qv29_mode = {
>>   static const struct ili9341_config yx240qv29_data = {
>>       .funcs = &yx240qv29_funcs,
>>       .mode = &yx240qv29_mode,
>> +    .no_dpi = true,
>>   };
>>     static int mi0283qt_prepare(struct drm_panel *panel)
>> @@ -291,6 +295,7 @@ static const struct drm_display_mode mi0283qt_mode
>> = {
>>   static const struct ili9341_config mi0283qt_data = {
>>       .funcs = &mi0283qt_drm_funcs,
>>       .mode = &mi0283qt_mode,
>> +    .no_dpi = true,
>>   };
>>     /* Legacy, DRM driver name is ABI */
>> @@ -303,6 +308,7 @@ static int ili9341_probe(struct spi_device *spi)
>>       const struct spi_device_id *spi_id;
>>       struct device *dev = &spi->dev;
>>       struct drm_driver *driver;
>> +    struct device_node *port;
>>       struct mipi_dbi *dbi;
>>       struct gpio_desc *dc;
>>       struct ili9341 *ili;
>> @@ -357,21 +363,44 @@ static int ili9341_probe(struct spi_device *spi)
>>       ili->panel.dev = dev;
>>       ili->panel.funcs = ili->conf->funcs;
>>   -    if (ili->conf == &mi0283qt_data)
>> -        driver = &mi0283qt_drm_driver;
>> -    else
>> -        driver = &ili9341_drm_driver;
>>   -    return drm_mipi_dbi_panel_register(&ili->panel, &ili->dbidev,
>> driver,
>> -                       ili->conf->mode, rotation);
>> +    port = of_get_child_by_name(dev->of_node, "port");
>> +    if (port) {
>> +        of_node_put(port);
>> +        ili->use_dpi = true;
>> +    }
>> +
>> +    if (ili->conf->no_dpi)
>> +        ili->use_dpi = false;
> 
> then this can just be ili->use_dpi = ili->conf->use_dpi.
> 
>> +
>> +    if (ili->use_dpi) {
>> +        ret = drm_panel_add(&ili->panel);
>> +    } else {
>> +        if (ili->conf == &mi0283qt_data)
>> +            driver = &mi0283qt_drm_driver;
>> +        else
>> +            driver = &ili9341_drm_driver;
>> +
>> +        ret = drm_mipi_dbi_panel_register(&ili->panel, &ili->dbidev,
>> driver,
>> +                          ili->conf->mode, rotation);
>> +    }
>> +
>> +    return ret;
>>   }
>>     static int ili9341_remove(struct spi_device *spi)
>>   {
>>       struct ili9341 *ili = spi_get_drvdata(spi);
>>   -    drm_dev_unplug(&ili->dbidev.drm);
>> -    drm_atomic_helper_shutdown(&ili->dbidev.drm);
>> +    if (ili->use_dpi) {
>> +        drm_panel_remove(&ili->panel);
>> +        drm_panel_disable(&ili->panel);
>> +        drm_panel_unprepare(&ili->panel);
>> +        kfree(ili);
>> +    } else {
>> +        drm_dev_unplug(&ili->dbidev.drm);
>> +        drm_atomic_helper_shutdown(&ili->dbidev.drm);
>> +    }
>>         return 0;
>>   }
>> @@ -380,21 +409,26 @@ static void ili9341_shutdown(struct spi_device
>> *spi)
>>   {
>>       struct ili9341 *ili = spi_get_drvdata(spi);
>>   -    drm_atomic_helper_shutdown(&ili->dbidev.drm);
>> +    if (!ili->use_dpi)
>> +        drm_atomic_helper_shutdown(&ili->dbidev.drm);
>>   }
>>     static int __maybe_unused ili9341_pm_suspend(struct device *dev)
>>   {
>>       struct ili9341 *ili = dev_get_drvdata(dev);
>>   -    return drm_mode_config_helper_suspend(&ili->dbidev.drm);
>> +    if (!ili->use_dpi)
>> +        return drm_mode_config_helper_suspend(&ili->dbidev.drm);
>> +
>> +    return 0;
>>   }
>>     static int __maybe_unused ili9341_pm_resume(struct device *dev)
>>   {
>>       struct ili9341 *ili = dev_get_drvdata(dev);
>>   -    drm_mode_config_helper_resume(&ili->dbidev.drm);
>> +    if (!ili->use_dpi)
>> +        drm_mode_config_helper_resume(&ili->dbidev.drm);
>>         return 0;
>>   }
>>
>