[PATCH v6 41/42] drm/mediatek: mtk_hdmi_v2: Add debugfs ops and implement ABIST

[AngeloGioacchino Del Regno]

Il 14/02/25 06:21, CK Hu (胡俊光) ha scritto:
> On Tue, 2025-02-11 at 12:34 +0100, AngeloGioacchino Del Regno wrote:
>> External email : Please do not click links or open attachments until you have verified the sender or the content.
>>
>>
>> Implement the Automated Built-In Self-Test ABIST functionality
>> provided by the HDMIv2 IP and expose it through the "hdmi_abist"
>> debugfs file.
>>
>> Write "1" to this file to activate ABIST, or "0" to deactivate.
> 
> Describe what we would see when activate ABIST.
> Give some example of when to use it.
> 

Sure, I will.

>>
>> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
>> ---
>>   drivers/gpu/drm/mediatek/mtk_hdmi_v2.c | 123 +++++++++++++++++++++++++
>>   1 file changed, 123 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c b/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c
>> index 36b7f8d8d218..f4a086b92dae 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_hdmi_v2.c
>> @@ -1170,6 +1170,128 @@ static int mtk_hdmi_v2_hdmi_write_infoframe(struct drm_bridge *bridge,
>>          return 0;
>>   }
>>
>> +static int mtk_hdmi_v2_set_abist(struct mtk_hdmi *hdmi, bool enable)
>> +{
>> +       struct drm_display_mode *mode = &hdmi->mode;
>> +       int abist_format = -EINVAL;
>> +       bool interlaced;
>> +
>> +       if (!enable) {
>> +               regmap_clear_bits(hdmi->regs, TOP_CFG00, HDMI_ABIST_ENABLE);
>> +               return 0;
>> +       }
>> +
>> +       if (!mode->hdisplay || !mode->vdisplay)
>> +               return -EINVAL;
>> +
>> +       interlaced = mode->flags & DRM_MODE_FLAG_INTERLACE;
>> +
>> +       switch (mode->hdisplay) {
>> +       case 720:
>> +               if (mode->vdisplay == 480)
>> +                       abist_format = 2;
>> +               else if (mode->vdisplay == 576)
>> +                       abist_format = 11;
>> +               break;
>> +       case 1280:
>> +               if (mode->vdisplay == 720)
>> +                       abist_format = 3;
>> +               break;
>> +       case 1440:
>> +               if (mode->vdisplay == 480)
>> +                       abist_format = interlaced ? 5 : 9;
>> +               else if (mode->vdisplay == 576)
>> +                       abist_format = interlaced ? 14 : 18;
>> +               break;
>> +       case 1920:
>> +               if (mode->vdisplay == 1080)
>> +                       abist_format = interlaced ? 4 : 10;
>> +               break;
>> +       case 3840:
>> +               if (mode->vdisplay == 2160)
>> +                       abist_format = 25;
>> +               break;
>> +       case 4096:
>> +               if (mode->vdisplay == 2160)
>> +                       abist_format = 26;
>> +               break;
>> +       default:
>> +               break;
>> +       }
>> +       if (!abist_format)
> 
> abist_format's initial value is -EINVAL, so this checking would never be true.
> Let abist_format's initial value be zero.
> 

No, because abist_format 0 is a valid format.

I'll change this to

if (abist_format < 0)
	return abist_format;

Thanks!

Regards,
Angelo

> Regards,
> CK
> 
>> +               return -EINVAL;
>> +
>> +       regmap_update_bits(hdmi->regs, TOP_CFG00, HDMI_ABIST_VIDEO_FORMAT,
>> +                          FIELD_PREP(HDMI_ABIST_VIDEO_FORMAT, abist_format));
>> +       regmap_set_bits(hdmi->regs, TOP_CFG00, HDMI_ABIST_ENABLE);
>> +       return 0;
>> +}
>> +
>> +static int mtk_hdmi_v2_debug_abist_show(struct seq_file *m, void *arg)
>> +{
>> +       struct mtk_hdmi *hdmi = m->private;
>> +       bool en;
>> +       u32 val;
>> +       int ret;
>> +
>> +       if (!hdmi)
>> +               return -EINVAL;
>> +
>> +       ret = regmap_read(hdmi->regs, TOP_CFG00, &val);
>> +       if (ret)
>> +               return ret;
>> +
>> +       en = FIELD_GET(HDMI_ABIST_ENABLE, val);
>> +
>> +       seq_printf(m, "HDMI Automated Built-In Self Test: %s\n",
>> +                  en ? "Enabled" : "Disabled");
>> +
>> +       return 0;
>> +}
>> +
>> +static ssize_t mtk_hdmi_v2_debug_abist_write(struct file *file,
>> +                                            const char __user *ubuf,
>> +                                            size_t len, loff_t *offp)
>> +{
>> +       struct seq_file *m = file->private_data;
>> +       int ret;
>> +       u32 en;
>> +
>> +       if (!m || !m->private || *offp)
>> +               return -EINVAL;
>> +
>> +       ret = kstrtouint_from_user(ubuf, len, 0, &en);
>> +       if (ret)
>> +               return ret;
>> +
>> +       if (en < 0 || en > 1)
>> +               return -EINVAL;
>> +
>> +       mtk_hdmi_v2_set_abist((struct mtk_hdmi *)m->private, en);
>> +       return len;
>> +}
>> +
>> +static int mtk_hdmi_v2_debug_abist_open(struct inode *inode, struct file *file)
>> +{
>> +       return single_open(file, mtk_hdmi_v2_debug_abist_show, inode->i_private);
>> +}
>> +
>> +static const struct file_operations mtk_hdmi_debug_abist_fops = {
>> +       .owner = THIS_MODULE,
>> +       .open = mtk_hdmi_v2_debug_abist_open,
>> +       .read = seq_read,
>> +       .write = mtk_hdmi_v2_debug_abist_write,
>> +       .llseek = seq_lseek,
>> +       .release = single_release,
>> +};
>> +
>> +static void mtk_hdmi_v2_debugfs_init(struct drm_bridge *bridge, struct dentry *root)
>> +{
>> +       struct mtk_hdmi *dpi = hdmi_ctx_from_bridge(bridge);
>> +
>> +       debugfs_create_file("hdmi_abist", 0640, root, dpi, &mtk_hdmi_debug_abist_fops);
>> +}
>> +
>>   static const struct drm_bridge_funcs mtk_v2_hdmi_bridge_funcs = {
>>          .attach = mtk_hdmi_v2_bridge_attach,
>>          .detach = mtk_hdmi_v2_bridge_detach,
>> @@ -1189,6 +1311,7 @@ static const struct drm_bridge_funcs mtk_v2_hdmi_bridge_funcs = {
>>          .hdmi_tmds_char_rate_valid = mtk_hdmi_v2_hdmi_tmds_char_rate_valid,
>>          .hdmi_clear_infoframe = mtk_hdmi_v2_hdmi_clear_infoframe,
>>          .hdmi_write_infoframe = mtk_hdmi_v2_hdmi_write_infoframe,
>> +       .debugfs_init = mtk_hdmi_v2_debugfs_init,
>>   };
>>
>>   /*
>> --
>> 2.48.1
>>
>