2021-12-15 21:48:57

by Yannick Fertre

[permalink] [raw]
Subject: [PATCH 5/5] drm/stm: ltdc: add support of ycbcr pixel formats

This patch adds the following YCbCr input pixel formats on the latest
LTDC hardware version:

1 plane (co-planar) : YUYV, YVYU, UYVY, VYUY
2 planes (semi-planar): NV12, NV21
3 planes (full-planar): YU12=I420=DRM YUV420, YV12=DRM YVU420

Signed-off-by: Yannick Fertre <[email protected]>
---
drivers/gpu/drm/stm/ltdc.c | 251 +++++++++++++++++++++++++++++++++++--
drivers/gpu/drm/stm/ltdc.h | 1 +
2 files changed, 245 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 4d249bc99894..7fd173390b9f 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -198,6 +198,21 @@

#define LXCFBLNR_CFBLN GENMASK(10, 0) /* Color Frame Buffer Line Number */

+#define LXCR_C1R_YIA BIT(0) /* Ycbcr 422 Interleaved Ability */
+#define LXCR_C1R_YSPA BIT(1) /* Ycbcr 420 Semi-Planar Ability */
+#define LXCR_C1R_YFPA BIT(2) /* Ycbcr 420 Full-Planar Ability */
+#define LXCR_C1R_SCA BIT(31) /* SCaling Ability*/
+
+#define LxPCR_YREN BIT(9) /* Y Rescale Enable for the color dynamic range */
+#define LxPCR_OF BIT(8) /* Odd pixel First */
+#define LxPCR_CBF BIT(7) /* CB component First */
+#define LxPCR_YF BIT(6) /* Y component First */
+#define LxPCR_YCM GENMASK(5, 4) /* Ycbcr Conversion Mode */
+#define YCM_I 0x0 /* Interleaved 422 */
+#define YCM_SP 0x1 /* Semi-Planar 420 */
+#define YCM_FP 0x2 /* Full-Planar 420 */
+#define LxPCR_YCEN BIT(3) /* YCbCr-to-RGB Conversion Enable */
+
#define LXRCR_IMR BIT(0) /* IMmediate Reload */
#define LXRCR_VBR BIT(1) /* Vertical Blanking Reload */
#define LXRCR_GRMSK BIT(2) /* Global (centralized) Reload MaSKed */
@@ -311,6 +326,23 @@ static const u32 ltdc_drm_fmt_a2[] = {
DRM_FORMAT_C8
};

+static const u32 ltdc_drm_fmt_ycbcr_cp[] = {
+ DRM_FORMAT_YUYV,
+ DRM_FORMAT_YVYU,
+ DRM_FORMAT_UYVY,
+ DRM_FORMAT_VYUY
+};
+
+static const u32 ltdc_drm_fmt_ycbcr_sp[] = {
+ DRM_FORMAT_NV12,
+ DRM_FORMAT_NV21
+};
+
+static const u32 ltdc_drm_fmt_ycbcr_fp[] = {
+ DRM_FORMAT_YUV420,
+ DRM_FORMAT_YVU420
+};
+
/* Layer register offsets */
static const u32 ltdc_layer_regs_a0[] = {
0x80, /* L1 configuration 0 */
@@ -410,6 +442,26 @@ static const struct regmap_config stm32_ltdc_regmap_cfg = {
.cache_type = REGCACHE_NONE,
};

+static const u32 ltdc_ycbcr2rgb_coeffs[DRM_COLOR_ENCODING_MAX][DRM_COLOR_RANGE_MAX][2] = {
+ [DRM_COLOR_YCBCR_BT601][DRM_COLOR_YCBCR_LIMITED_RANGE] = {
+ 0x02040199, /* (b_cb = 516 / r_cr = 409) */
+ 0x006400D0 /* (g_cb = 100 / g_cr = 208) */
+ },
+ [DRM_COLOR_YCBCR_BT601][DRM_COLOR_YCBCR_FULL_RANGE] = {
+ 0x01C60167, /* (b_cb = 454 / r_cr = 359) */
+ 0x005800B7 /* (g_cb = 88 / g_cr = 183) */
+ },
+ [DRM_COLOR_YCBCR_BT709][DRM_COLOR_YCBCR_LIMITED_RANGE] = {
+ 0x021D01CB, /* (b_cb = 541 / r_cr = 459) */
+ 0x00370089 /* (g_cb = 55 / g_cr = 137) */
+ },
+ [DRM_COLOR_YCBCR_BT709][DRM_COLOR_YCBCR_FULL_RANGE] = {
+ 0x01DB0193, /* (b_cb = 475 / r_cr = 403) */
+ 0x00300078 /* (g_cb = 48 / g_cr = 120) */
+ }
+ /* BT2020 not supported */
+};
+
static inline struct ltdc_device *crtc_to_ltdc(struct drm_crtc *crtc)
{
return (struct ltdc_device *)crtc->dev->dev_private;
@@ -540,6 +592,78 @@ static inline u32 is_xrgb(u32 drm)
return ((drm & 0xFF) == 'X' || ((drm >> 8) & 0xFF) == 'X');
}

+static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fmt)
+{
+ struct ltdc_device *ldev = plane_to_ltdc(plane);
+ struct drm_plane_state *state = plane->state;
+ u32 lofs = plane->index * LAY_OFS;
+ u32 val;
+
+ switch (drm_pix_fmt) {
+ case DRM_FORMAT_YUYV:
+ val = (YCM_I << 4) | LxPCR_YF | LxPCR_CBF;
+ break;
+ case DRM_FORMAT_YVYU:
+ val = (YCM_I << 4) | LxPCR_YF;
+ break;
+ case DRM_FORMAT_UYVY:
+ val = (YCM_I << 4) | LxPCR_CBF;
+ break;
+ case DRM_FORMAT_VYUY:
+ val = (YCM_I << 4);
+ break;
+ case DRM_FORMAT_NV12:
+ val = (YCM_SP << 4) | LxPCR_CBF;
+ break;
+ case DRM_FORMAT_NV21:
+ val = (YCM_SP << 4);
+ break;
+ case DRM_FORMAT_YUV420:
+ case DRM_FORMAT_YVU420:
+ val = (YCM_FP << 4);
+ break;
+ default:
+ /* RGB or not a YCbCr supported format */
+ break;
+ }
+
+ /* Enable limited range */
+ if (state->color_range == DRM_COLOR_YCBCR_LIMITED_RANGE)
+ val |= LxPCR_YREN;
+
+ /* enable ycbcr conversion */
+ val |= LxPCR_YCEN;
+
+ regmap_write(ldev->regmap, LTDC_L1PCR + lofs, val);
+}
+
+static inline void ltdc_set_ycbcr_coeffs(struct drm_plane *plane)
+{
+ struct ltdc_device *ldev = plane_to_ltdc(plane);
+ struct drm_plane_state *state = plane->state;
+ enum drm_color_encoding enc = state->color_encoding;
+ enum drm_color_range ran = state->color_range;
+ u32 lofs = plane->index * LAY_OFS;
+
+ if (enc != DRM_COLOR_YCBCR_BT601 && enc != DRM_COLOR_YCBCR_BT709) {
+ DRM_ERROR("color encoding %d not supported, use bt601 by default\n", enc);
+ /* set by default color encoding to DRM_COLOR_YCBCR_BT601 */
+ enc = DRM_COLOR_YCBCR_BT601;
+ }
+
+ if (ran != DRM_COLOR_YCBCR_LIMITED_RANGE && ran != DRM_COLOR_YCBCR_FULL_RANGE) {
+ DRM_ERROR("color range %d not supported, use limited range by default\n", ran);
+ /* set by default color range to DRM_COLOR_YCBCR_LIMITED_RANGE */
+ ran = DRM_COLOR_YCBCR_LIMITED_RANGE;
+ }
+
+ DRM_DEBUG_DRIVER("Color encoding=%d, range=%d\n", enc, ran);
+ regmap_write(ldev->regmap, LTDC_L1CYR0R + lofs,
+ ltdc_ycbcr2rgb_coeffs[enc][ran][0]);
+ regmap_write(ldev->regmap, LTDC_L1CYR1R + lofs,
+ ltdc_ycbcr2rgb_coeffs[enc][ran][1]);
+}
+
static irqreturn_t ltdc_irq_thread(int irq, void *arg)
{
struct drm_device *ddev = arg;
@@ -1010,7 +1134,7 @@ static void ltdc_plane_atomic_update(struct drm_plane *plane,
u32 y0 = newstate->crtc_y;
u32 y1 = newstate->crtc_y + newstate->crtc_h - 1;
u32 src_x, src_y, src_w, src_h;
- u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
+ u32 val, pitch_in_bytes, line_length, line_number, paddr, ahbp, avbp, bpcr;
enum ltdc_pix_fmt pf;

if (!newstate->crtc || !fb) {
@@ -1086,8 +1210,8 @@ static void ltdc_plane_atomic_update(struct drm_plane *plane,
regmap_write_bits(ldev->regmap, LTDC_L1BFCR + lofs, LXBFCR_BF2 | LXBFCR_BF1, val);

/* Configures the frame buffer line number */
- val = y1 - y0 + 1;
- regmap_write_bits(ldev->regmap, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, val);
+ line_number = y1 - y0 + 1;
+ regmap_write_bits(ldev->regmap, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, line_number);

/* Sets the FB address */
paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 0);
@@ -1095,6 +1219,77 @@ static void ltdc_plane_atomic_update(struct drm_plane *plane,
DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
regmap_write(ldev->regmap, LTDC_L1CFBAR + lofs, paddr);

+ if (ldev->caps.ycbcr_input) {
+ if (fb->format->is_yuv) {
+ switch (fb->format->format) {
+ case DRM_FORMAT_NV12:
+ case DRM_FORMAT_NV21:
+ /* Configure the auxiliary frame buffer address 0 & 1 */
+ paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 1);
+ regmap_write(ldev->regmap, LTDC_L1AFBA0R + lofs, paddr);
+ regmap_write(ldev->regmap, LTDC_L1AFBA1R + lofs, paddr + 1);
+
+ /* Configure the buffer length */
+ val = ((pitch_in_bytes << 16) | line_length);
+ regmap_write(ldev->regmap, LTDC_L1AFBLR + lofs, val);
+
+ /* Configure the frame buffer line number */
+ val = (line_number >> 1);
+ regmap_write(ldev->regmap, LTDC_L1AFBLNR + lofs, val);
+ break;
+ case DRM_FORMAT_YUV420:
+ /* Configure the auxiliary frame buffer address 0 */
+ paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 1);
+ regmap_write(ldev->regmap, LTDC_L1AFBA0R + lofs, paddr);
+
+ /* Configure the auxiliary frame buffer address 1 */
+ paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 2);
+ regmap_write(ldev->regmap, LTDC_L1AFBA1R + lofs, paddr);
+
+ line_length = ((fb->format->cpp[0] * (x1 - x0 + 1)) >> 1) +
+ (ldev->caps.bus_width >> 3) - 1;
+
+ /* Configure the buffer length */
+ val = (((pitch_in_bytes >> 1) << 16) | line_length);
+ regmap_write(ldev->regmap, LTDC_L1AFBLR + lofs, val);
+
+ /* Configure the frame buffer line number */
+ val = (line_number >> 1);
+ regmap_write(ldev->regmap, LTDC_L1AFBLNR + lofs, val);
+ break;
+ case DRM_FORMAT_YVU420:
+ /* Configure the auxiliary frame buffer address 0 */
+ paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 2);
+ regmap_write(ldev->regmap, LTDC_L1AFBA0R + lofs, paddr);
+
+ /* Configure the auxiliary frame buffer address 1 */
+ paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 1);
+ regmap_write(ldev->regmap, LTDC_L1AFBA1R + lofs, paddr);
+
+ line_length = ((fb->format->cpp[0] * (x1 - x0 + 1)) >> 1) +
+ (ldev->caps.bus_width >> 3) - 1;
+
+ /* Configure the buffer length */
+ val = (((pitch_in_bytes >> 1) << 16) | line_length);
+ regmap_write(ldev->regmap, LTDC_L1AFBLR + lofs, val);
+
+ /* Configure the frame buffer line number */
+ val = (line_number >> 1);
+ regmap_write(ldev->regmap, LTDC_L1AFBLNR + lofs, val);
+ break;
+ }
+
+ /* Configure YCbC conversion coefficient */
+ ltdc_set_ycbcr_coeffs(plane);
+
+ /* Configure YCbCr format and enable/disable conversion */
+ ltdc_set_ycbcr_config(plane, fb->format->format);
+ } else {
+ /* disable ycbcr conversion */
+ regmap_write(ldev->regmap, LTDC_L1PCR + lofs, 0);
+ }
+ }
+
/* Enable layer and CLUT if needed */
val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
val |= LXCR_LEN;
@@ -1186,7 +1381,8 @@ static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
};

static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
- enum drm_plane_type type)
+ enum drm_plane_type type,
+ int index)
{
unsigned long possible_crtcs = CRTC_MASK;
struct ltdc_device *ldev = ddev->dev_private;
@@ -1196,9 +1392,16 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
u32 *formats;
u32 drm_fmt;
const u64 *modifiers = ltdc_format_modifiers;
+ u32 lofs = index * LAY_OFS;
+ u32 val;
int ret;

- formats = devm_kzalloc(dev, ldev->caps.pix_fmt_nb * sizeof(*formats), GFP_KERNEL);
+ /* Allocate the biggest size according to supported color formats */
+ formats = devm_kzalloc(dev, (ldev->caps.pix_fmt_nb +
+ ARRAY_SIZE(ltdc_drm_fmt_ycbcr_cp) +
+ ARRAY_SIZE(ltdc_drm_fmt_ycbcr_sp) +
+ ARRAY_SIZE(ltdc_drm_fmt_ycbcr_fp)) *
+ sizeof(*formats), GFP_KERNEL);

for (i = 0; i < ldev->caps.pix_fmt_nb; i++) {
drm_fmt = ldev->caps.pix_fmt_drm[i];
@@ -1212,6 +1415,26 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
formats[nb_fmt++] = drm_fmt;
}

+ /* Add YCbCr supported pixel formats */
+ if (ldev->caps.ycbcr_input) {
+ regmap_read(ldev->regmap, LTDC_L1C1R + lofs, &val);
+ if (val & LXCR_C1R_YIA) {
+ memcpy(&formats[nb_fmt], ltdc_drm_fmt_ycbcr_cp,
+ ARRAY_SIZE(ltdc_drm_fmt_ycbcr_cp) * sizeof(*formats));
+ nb_fmt += ARRAY_SIZE(ltdc_drm_fmt_ycbcr_cp);
+ }
+ if (val & LXCR_C1R_YSPA) {
+ memcpy(&formats[nb_fmt], ltdc_drm_fmt_ycbcr_sp,
+ ARRAY_SIZE(ltdc_drm_fmt_ycbcr_sp) * sizeof(*formats));
+ nb_fmt += ARRAY_SIZE(ltdc_drm_fmt_ycbcr_sp);
+ }
+ if (val & LXCR_C1R_YFPA) {
+ memcpy(&formats[nb_fmt], ltdc_drm_fmt_ycbcr_fp,
+ ARRAY_SIZE(ltdc_drm_fmt_ycbcr_fp) * sizeof(*formats));
+ nb_fmt += ARRAY_SIZE(ltdc_drm_fmt_ycbcr_fp);
+ }
+ }
+
plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
if (!plane)
return NULL;
@@ -1222,6 +1445,17 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
if (ret < 0)
return NULL;

+ if (ldev->caps.ycbcr_input) {
+ if (val & (LXCR_C1R_YIA | LXCR_C1R_YSPA | LXCR_C1R_YFPA))
+ drm_plane_create_color_properties(plane,
+ BIT(DRM_COLOR_YCBCR_BT601) |
+ BIT(DRM_COLOR_YCBCR_BT709),
+ BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
+ BIT(DRM_COLOR_YCBCR_FULL_RANGE),
+ DRM_COLOR_YCBCR_BT601,
+ DRM_COLOR_YCBCR_LIMITED_RANGE);
+ }
+
drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);

drm_plane_create_alpha_property(plane);
@@ -1247,7 +1481,7 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
unsigned int i;
int ret;

- primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
+ primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY, 0);
if (!primary) {
DRM_ERROR("Can not create primary plane\n");
return -EINVAL;
@@ -1271,7 +1505,7 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)

/* Add planes. Note : the first layer is used by primary plane */
for (i = 1; i < ldev->caps.nb_layers; i++) {
- overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
+ overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY, i);
if (!overlay) {
ret = -ENOMEM;
DRM_ERROR("Can not create overlay plane %d\n", i);
@@ -1403,6 +1637,7 @@ static int ltdc_get_caps(struct drm_device *ddev)
if (ldev->caps.hw_version == HWVER_10200)
ldev->caps.pad_max_freq_hz = 65000000;
ldev->caps.nb_irq = 2;
+ ldev->caps.ycbcr_input = false;
ldev->caps.ycbcr_output = false;
ldev->caps.plane_reg_shadow = false;
break;
@@ -1416,6 +1651,7 @@ static int ltdc_get_caps(struct drm_device *ddev)
ldev->caps.non_alpha_only_l1 = false;
ldev->caps.pad_max_freq_hz = 150000000;
ldev->caps.nb_irq = 4;
+ ldev->caps.ycbcr_input = false;
ldev->caps.ycbcr_output = false;
ldev->caps.plane_reg_shadow = false;
break;
@@ -1429,6 +1665,7 @@ static int ltdc_get_caps(struct drm_device *ddev)
ldev->caps.non_alpha_only_l1 = false;
ldev->caps.pad_max_freq_hz = 90000000;
ldev->caps.nb_irq = 2;
+ ldev->caps.ycbcr_input = true;
ldev->caps.ycbcr_output = true;
ldev->caps.plane_reg_shadow = true;
break;
diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
index adc4f9cf7f95..6968d1ca5149 100644
--- a/drivers/gpu/drm/stm/ltdc.h
+++ b/drivers/gpu/drm/stm/ltdc.h
@@ -24,6 +24,7 @@ struct ltdc_caps {
bool non_alpha_only_l1; /* non-native no-alpha formats on layer 1 */
int pad_max_freq_hz; /* max frequency supported by pad */
int nb_irq; /* number of hardware interrupts */
+ bool ycbcr_input; /* ycbcr input converter supported */
bool ycbcr_output; /* ycbcr output converter supported */
bool plane_reg_shadow; /* plane shadow registers ability */
};
--
2.17.1



2022-01-04 10:28:10

by Philippe CORNU

[permalink] [raw]
Subject: Re: [PATCH 5/5] drm/stm: ltdc: add support of ycbcr pixel formats



On 12/15/21 10:48 PM, Yannick Fertre wrote:
> This patch adds the following YCbCr input pixel formats on the latest
> LTDC hardware version:
>
> 1 plane (co-planar) : YUYV, YVYU, UYVY, VYUY
> 2 planes (semi-planar): NV12, NV21
> 3 planes (full-planar): YU12=I420=DRM YUV420, YV12=DRM YVU420
>
> Signed-off-by: Yannick Fertre <[email protected]>
> ---
> drivers/gpu/drm/stm/ltdc.c | 251 +++++++++++++++++++++++++++++++++++--
> drivers/gpu/drm/stm/ltdc.h | 1 +
> 2 files changed, 245 insertions(+), 7 deletions(-)
>

Hi Yannick,
many thanks for your patch.
Nice hw features!
Acked-by: Philippe Cornu <[email protected]>
Reviewed-by: Philippe Cornu <[email protected]>
Philippe :-)

2022-02-02 18:58:03

by Nathan Chancellor

[permalink] [raw]
Subject: Re: [PATCH 5/5] drm/stm: ltdc: add support of ycbcr pixel formats

Hi Yannick,

On Wed, Dec 15, 2021 at 10:48:43PM +0100, Yannick Fertre wrote:
> This patch adds the following YCbCr input pixel formats on the latest
> LTDC hardware version:
>
> 1 plane (co-planar) : YUYV, YVYU, UYVY, VYUY
> 2 planes (semi-planar): NV12, NV21
> 3 planes (full-planar): YU12=I420=DRM YUV420, YV12=DRM YVU420
>
> Signed-off-by: Yannick Fertre <[email protected]>

<snip>

> +static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fmt)
> +{
> + struct ltdc_device *ldev = plane_to_ltdc(plane);
> + struct drm_plane_state *state = plane->state;
> + u32 lofs = plane->index * LAY_OFS;
> + u32 val;
> +
> + switch (drm_pix_fmt) {
> + case DRM_FORMAT_YUYV:
> + val = (YCM_I << 4) | LxPCR_YF | LxPCR_CBF;
> + break;
> + case DRM_FORMAT_YVYU:
> + val = (YCM_I << 4) | LxPCR_YF;
> + break;
> + case DRM_FORMAT_UYVY:
> + val = (YCM_I << 4) | LxPCR_CBF;
> + break;
> + case DRM_FORMAT_VYUY:
> + val = (YCM_I << 4);
> + break;
> + case DRM_FORMAT_NV12:
> + val = (YCM_SP << 4) | LxPCR_CBF;
> + break;
> + case DRM_FORMAT_NV21:
> + val = (YCM_SP << 4);
> + break;
> + case DRM_FORMAT_YUV420:
> + case DRM_FORMAT_YVU420:
> + val = (YCM_FP << 4);
> + break;
> + default:
> + /* RGB or not a YCbCr supported format */
> + break;
> + }
> +
> + /* Enable limited range */
> + if (state->color_range == DRM_COLOR_YCBCR_LIMITED_RANGE)
> + val |= LxPCR_YREN;
> +
> + /* enable ycbcr conversion */
> + val |= LxPCR_YCEN;
> +
> + regmap_write(ldev->regmap, LTDC_L1PCR + lofs, val);
> +}

This patch as commit 484e72d3146b ("drm/stm: ltdc: add support of ycbcr
pixel formats") in -next introduced the following clang warning:

drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
default:
^~~~~~~
drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here
val |= LxPCR_YCEN;
^~~
drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning
u32 val;
^
= 0
1 warning generated.

Would it be okay to just return in the default case (maybe with a
message about an unsupported format?) or should there be another fix?

Cheers,

2022-02-09 09:05:40

by Yannick Fertre

[permalink] [raw]
Subject: Re: [PATCH 5/5] drm/stm: ltdc: add support of ycbcr pixel formats

Hi Nathan,

On 2/2/22 17:54, Nathan Chancellor wrote:
> Hi Yannick,
>
> On Wed, Dec 15, 2021 at 10:48:43PM +0100, Yannick Fertre wrote:
>> This patch adds the following YCbCr input pixel formats on the latest
>> LTDC hardware version:
>>
>> 1 plane (co-planar) : YUYV, YVYU, UYVY, VYUY
>> 2 planes (semi-planar): NV12, NV21
>> 3 planes (full-planar): YU12=I420=DRM YUV420, YV12=DRM YVU420
>>
>> Signed-off-by: Yannick Fertre <[email protected]>
>
> <snip>
>
>> +static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fmt)
>> +{
>> + struct ltdc_device *ldev = plane_to_ltdc(plane);
>> + struct drm_plane_state *state = plane->state;
>> + u32 lofs = plane->index * LAY_OFS;
>> + u32 val;
>> +
>> + switch (drm_pix_fmt) {
>> + case DRM_FORMAT_YUYV:
>> + val = (YCM_I << 4) | LxPCR_YF | LxPCR_CBF;
>> + break;
>> + case DRM_FORMAT_YVYU:
>> + val = (YCM_I << 4) | LxPCR_YF;
>> + break;
>> + case DRM_FORMAT_UYVY:
>> + val = (YCM_I << 4) | LxPCR_CBF;
>> + break;
>> + case DRM_FORMAT_VYUY:
>> + val = (YCM_I << 4);
>> + break;
>> + case DRM_FORMAT_NV12:
>> + val = (YCM_SP << 4) | LxPCR_CBF;
>> + break;
>> + case DRM_FORMAT_NV21:
>> + val = (YCM_SP << 4);
>> + break;
>> + case DRM_FORMAT_YUV420:
>> + case DRM_FORMAT_YVU420:
>> + val = (YCM_FP << 4);
>> + break;
>> + default:
>> + /* RGB or not a YCbCr supported format */
>> + break;
>> + }
>> +
>> + /* Enable limited range */
>> + if (state->color_range == DRM_COLOR_YCBCR_LIMITED_RANGE)
>> + val |= LxPCR_YREN;
>> +
>> + /* enable ycbcr conversion */
>> + val |= LxPCR_YCEN;
>> +
>> + regmap_write(ldev->regmap, LTDC_L1PCR + lofs, val);
>> +}
>
> This patch as commit 484e72d3146b ("drm/stm: ltdc: add support of ycbcr
> pixel formats") in -next introduced the following clang warning:
>
> drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
> default:
> ^~~~~~~
> drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here
> val |= LxPCR_YCEN;
> ^~~
> drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning
> u32 val;
> ^
> = 0
> 1 warning generated.
>
> Would it be okay to just return in the default case (maybe with a
> message about an unsupported format?) or should there be another fix?
>
> Cheers,


Thanks for your help.
It'okay for a message for unsupported format with a return in the
default case.
Do you want create & push the patch?

Best regards

2022-02-09 09:31:23

by Nathan Chancellor

[permalink] [raw]
Subject: Re: [PATCH 5/5] drm/stm: ltdc: add support of ycbcr pixel formats

On Mon, Feb 07, 2022 at 11:00:34AM +0100, yannick Fertre wrote:
> Hi Nathan,
>
> On 2/2/22 17:54, Nathan Chancellor wrote:
> > Hi Yannick,
> >
> > On Wed, Dec 15, 2021 at 10:48:43PM +0100, Yannick Fertre wrote:
> > > This patch adds the following YCbCr input pixel formats on the latest
> > > LTDC hardware version:
> > >
> > > 1 plane (co-planar) : YUYV, YVYU, UYVY, VYUY
> > > 2 planes (semi-planar): NV12, NV21
> > > 3 planes (full-planar): YU12=I420=DRM YUV420, YV12=DRM YVU420
> > >
> > > Signed-off-by: Yannick Fertre <[email protected]>
> >
> > <snip>
> >
> > > +static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fmt)
> > > +{
> > > + struct ltdc_device *ldev = plane_to_ltdc(plane);
> > > + struct drm_plane_state *state = plane->state;
> > > + u32 lofs = plane->index * LAY_OFS;
> > > + u32 val;
> > > +
> > > + switch (drm_pix_fmt) {
> > > + case DRM_FORMAT_YUYV:
> > > + val = (YCM_I << 4) | LxPCR_YF | LxPCR_CBF;
> > > + break;
> > > + case DRM_FORMAT_YVYU:
> > > + val = (YCM_I << 4) | LxPCR_YF;
> > > + break;
> > > + case DRM_FORMAT_UYVY:
> > > + val = (YCM_I << 4) | LxPCR_CBF;
> > > + break;
> > > + case DRM_FORMAT_VYUY:
> > > + val = (YCM_I << 4);
> > > + break;
> > > + case DRM_FORMAT_NV12:
> > > + val = (YCM_SP << 4) | LxPCR_CBF;
> > > + break;
> > > + case DRM_FORMAT_NV21:
> > > + val = (YCM_SP << 4);
> > > + break;
> > > + case DRM_FORMAT_YUV420:
> > > + case DRM_FORMAT_YVU420:
> > > + val = (YCM_FP << 4);
> > > + break;
> > > + default:
> > > + /* RGB or not a YCbCr supported format */
> > > + break;
> > > + }
> > > +
> > > + /* Enable limited range */
> > > + if (state->color_range == DRM_COLOR_YCBCR_LIMITED_RANGE)
> > > + val |= LxPCR_YREN;
> > > +
> > > + /* enable ycbcr conversion */
> > > + val |= LxPCR_YCEN;
> > > +
> > > + regmap_write(ldev->regmap, LTDC_L1PCR + lofs, val);
> > > +}
> >
> > This patch as commit 484e72d3146b ("drm/stm: ltdc: add support of ycbcr
> > pixel formats") in -next introduced the following clang warning:
> >
> > drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
> > default:
> > ^~~~~~~
> > drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here
> > val |= LxPCR_YCEN;
> > ^~~
> > drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning
> > u32 val;
> > ^
> > = 0
> > 1 warning generated.
> >
> > Would it be okay to just return in the default case (maybe with a
> > message about an unsupported format?) or should there be another fix?
> >
> > Cheers,
>
>
> Thanks for your help.
> It'okay for a message for unsupported format with a return in the default
> case.
> Do you want create & push the patch?

Thank you for the input! I have sent a fix now, please take a look.

https://lore.kernel.org/r/[email protected]/

Cheers,
Nathan