Re: [PATCH v5 21/22] drm/vc4: vec: Add support for more analog TV standards

2022-10-16 Thread Mateusz Kwiatkowski
Hi Maxime,

W dniu 13.10.2022 o 15:19, Maxime Ripard pisze:
> From: Mateusz Kwiatkowski 
>
> Add support for the following composite output modes (all of them are
> somewhat more obscure than the previously defined ones):
>
> - NTSC_443 - NTSC-style signal with the chroma subcarrier shifted to
>   4.43361875 MHz (the PAL subcarrier frequency). Never used for
>   broadcasting, but sometimes used as a hack to play NTSC content in PAL
>   regions (e.g. on VCRs).
> - PAL_N - PAL with alternative chroma subcarrier frequency,
>   3.58205625 MHz. Used as a broadcast standard in Argentina, Paraguay
>   and Uruguay to fit 576i50 with colour in 6 MHz channel raster.
> - PAL60 - 480i60 signal with PAL-style color at normal European PAL
>   frequency. Another non-standard, non-broadcast mode, used in similar
>   contexts as NTSC_443. Some displays support one but not the other.

The current version actually does not support PAL-60. Proper PAL-60 output from
VEC requires configuring it differently than for regular PAL. We have unified
the PAL and PAL-60 modes for the "TV mode" property, but the code here has not
been adjusted appropriately.

I'll try to submit an additional patch that fixes this shortly.

> - SECAM - French frequency-modulated analog color standard; also have
>   been broadcast in Eastern Europe and various parts of Africa and Asia.
>   Uses the same 576i50 timings as PAL.
>
> Also added some comments explaining color subcarrier frequency
> registers.
>
> Acked-by: Noralf Trønnes 
> Signed-off-by: Mateusz Kwiatkowski 
> Signed-off-by: Maxime Ripard 
> ---
(snip)

Best regards,
Mateusz Kwiatkowski


[PATCH v5 21/22] drm/vc4: vec: Add support for more analog TV standards

2022-10-13 Thread Maxime Ripard
From: Mateusz Kwiatkowski 

Add support for the following composite output modes (all of them are
somewhat more obscure than the previously defined ones):

- NTSC_443 - NTSC-style signal with the chroma subcarrier shifted to
  4.43361875 MHz (the PAL subcarrier frequency). Never used for
  broadcasting, but sometimes used as a hack to play NTSC content in PAL
  regions (e.g. on VCRs).
- PAL_N - PAL with alternative chroma subcarrier frequency,
  3.58205625 MHz. Used as a broadcast standard in Argentina, Paraguay
  and Uruguay to fit 576i50 with colour in 6 MHz channel raster.
- PAL60 - 480i60 signal with PAL-style color at normal European PAL
  frequency. Another non-standard, non-broadcast mode, used in similar
  contexts as NTSC_443. Some displays support one but not the other.
- SECAM - French frequency-modulated analog color standard; also have
  been broadcast in Eastern Europe and various parts of Africa and Asia.
  Uses the same 576i50 timings as PAL.

Also added some comments explaining color subcarrier frequency
registers.

Acked-by: Noralf Trønnes 
Signed-off-by: Mateusz Kwiatkowski 
Signed-off-by: Maxime Ripard 
---
 drivers/gpu/drm/vc4/vc4_vec.c | 84 ++-
 1 file changed, 83 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_vec.c b/drivers/gpu/drm/vc4/vc4_vec.c
index 456689b45849..88b4330bfa39 100644
--- a/drivers/gpu/drm/vc4/vc4_vec.c
+++ b/drivers/gpu/drm/vc4/vc4_vec.c
@@ -46,6 +46,7 @@
 #define VEC_CONFIG0_YDEL(x)((x) << 26)
 #define VEC_CONFIG0_CDEL_MASK  GENMASK(25, 24)
 #define VEC_CONFIG0_CDEL(x)((x) << 24)
+#define VEC_CONFIG0_SECAM_STD  BIT(21)
 #define VEC_CONFIG0_PBPR_FIL   BIT(18)
 #define VEC_CONFIG0_CHROMA_GAIN_MASK   GENMASK(17, 16)
 #define VEC_CONFIG0_CHROMA_GAIN_UNITY  (0 << 16)
@@ -76,6 +77,27 @@
 #define VEC_SOFT_RESET 0x10c
 #define VEC_CLMP0_START0x144
 #define VEC_CLMP0_END  0x148
+
+/*
+ * These set the color subcarrier frequency
+ * if VEC_CONFIG1_CUSTOM_FREQ is enabled.
+ *
+ * VEC_FREQ1_0 contains the most significant 16-bit half-word,
+ * VEC_FREQ3_2 contains the least significant 16-bit half-word.
+ * 0x8000 seems to be equivalent to the pixel clock
+ * (which itself is the VEC clock divided by 8).
+ *
+ * Reference values (with the default pixel clock of 13.5 MHz):
+ *
+ * NTSC  (3579545.[45] Hz) - 0x21F07C1F
+ * PAL   (4433618.75 Hz)   - 0x2A098ACB
+ * PAL-M (3575611.[888111] Hz) - 0x21E6EFE3
+ * PAL-N (3582056.25 Hz)   - 0x21F69446
+ *
+ * NOTE: For SECAM, it is used as the Dr center frequency,
+ * regardless of whether VEC_CONFIG1_CUSTOM_FREQ is enabled or not;
+ * that is specified as 4406250 Hz, which corresponds to 0x29C71C72.
+ */
 #define VEC_FREQ3_20x180
 #define VEC_FREQ1_00x184
 
@@ -118,6 +140,14 @@
 
 #define VEC_INTERRUPT_CONTROL  0x190
 #define VEC_INTERRUPT_STATUS   0x194
+
+/*
+ * Db center frequency for SECAM; the clock for this is the same as for
+ * VEC_FREQ3_2/VEC_FREQ1_0, which is used for Dr center frequency.
+ *
+ * This is specified as 425 Hz, which corresponds to 0x284BDA13.
+ * That is also the default value, so no need to set it explicitly.
+ */
 #define VEC_FCW_SECAM_B0x198
 #define VEC_SECAM_GAIN_VAL 0x19c
 
@@ -197,6 +227,10 @@ enum vc4_vec_tv_mode_id {
VC4_VEC_TV_MODE_NTSC_J,
VC4_VEC_TV_MODE_PAL,
VC4_VEC_TV_MODE_PAL_M,
+   VC4_VEC_TV_MODE_NTSC_443,
+   VC4_VEC_TV_MODE_PAL_60,
+   VC4_VEC_TV_MODE_PAL_N,
+   VC4_VEC_TV_MODE_SECAM,
 };
 
 struct vc4_vec_tv_mode {
@@ -239,6 +273,12 @@ static const struct vc4_vec_tv_mode vc4_vec_tv_modes[] = {
.config0 = VEC_CONFIG0_NTSC_STD | VEC_CONFIG0_PDEN,
.config1 = VEC_CONFIG1_C_CVBS_CVBS,
},
+   {
+   .mode = DRM_MODE_TV_MODE_NTSC_443,
+   .config0 = VEC_CONFIG0_NTSC_STD,
+   .config1 = VEC_CONFIG1_C_CVBS_CVBS | VEC_CONFIG1_CUSTOM_FREQ,
+   .custom_freq = 0x2a098acb,
+   },
{
.mode = DRM_MODE_TV_MODE_NTSC_J,
.config0 = VEC_CONFIG0_NTSC_STD,
@@ -254,6 +294,17 @@ static const struct vc4_vec_tv_mode vc4_vec_tv_modes[] = {
.config0 = VEC_CONFIG0_PAL_M_STD,
.config1 = VEC_CONFIG1_C_CVBS_CVBS,
},
+   {
+   .mode = DRM_MODE_TV_MODE_PAL_N,
+   .config0 = VEC_CONFIG0_PAL_N_STD,
+   .config1 = VEC_CONFIG1_C_CVBS_CVBS,
+   },
+   {
+   .mode = DRM_MODE_TV_MODE_SECAM,
+   .config0 = VEC_CONFIG0_SECAM_STD,
+   .config1 = VEC_CONFIG1_C_CVBS_CVBS,
+   .custom_freq = 0x29c71c72,
+   },
 };
 
 static inline const struct vc4_vec_tv_mode *
@@ -273,9 +324,13 @@ vc4_vec_tv_mode_lookup(unsigned int mode)
 
 static const struct