Maxime Ripard
2022-Aug-29 13:11 UTC
[Nouveau] [PATCH v2 10/41] drm/modes: Add a function to generate analog display modes
Multiple drivers (meson, vc4, sun4i) define analog TV 525-lines and
625-lines modes in their drivers.
Since those modes are fairly standard, and that we'll need to use them
in more places in the future, it makes sense to move their definition
into the core framework.
However, analog display usually have fairly loose timings requirements,
the only discrete parameters being the total number of lines and pixel
clock frequency. Thus, we created a function that will create a display
mode from the standard, the pixel frequency and the active area.
Signed-off-by: Maxime Ripard <maxime at cerno.tech>
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 304004fb80aa..ee581ee17171 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -116,6 +116,459 @@ void drm_mode_probed_add(struct drm_connector *connector,
}
EXPORT_SYMBOL(drm_mode_probed_add);
+enum drm_mode_analog {
+ DRM_MODE_ANALOG_NTSC,
+ DRM_MODE_ANALOG_PAL,
+};
+
+/*
+ * The timings come from:
+ * -
https://web.archive.org/web/20220406232708/http://www.kolumbus.fi/pami1/video/pal_ntsc.html
+ * -
https://web.archive.org/web/20220406124914/http://martin.hinner.info/vga/pal.html
+ * -
https://web.archive.org/web/20220609202433/http://www.batsocks.co.uk/readme/video_timing.htm
+ */
+#define NTSC_LINE_DURATION_NS 63556U
+#define NTSC_LINES_NUMBER 525
+
+#define NTSC_HBLK_DURATION_TYP_NS 10900U
+#define NTSC_HBLK_DURATION_MIN_NS (NTSC_HBLK_DURATION_TYP_NS - 200)
+#define NTSC_HBLK_DURATION_MAX_NS (NTSC_HBLK_DURATION_TYP_NS + 200)
+
+#define NTSC_HACT_DURATION_TYP_NS (NTSC_LINE_DURATION_NS -
NTSC_HBLK_DURATION_TYP_NS)
+#define NTSC_HACT_DURATION_MIN_NS (NTSC_LINE_DURATION_NS -
NTSC_HBLK_DURATION_MAX_NS)
+#define NTSC_HACT_DURATION_MAX_NS (NTSC_LINE_DURATION_NS -
NTSC_HBLK_DURATION_MIN_NS)
+
+#define NTSC_HFP_DURATION_TYP_NS 1500
+#define NTSC_HFP_DURATION_MIN_NS 1270
+#define NTSC_HFP_DURATION_MAX_NS 2220
+
+#define NTSC_HSLEN_DURATION_TYP_NS 4700
+#define NTSC_HSLEN_DURATION_MIN_NS (NTSC_HSLEN_DURATION_TYP_NS - 100)
+#define NTSC_HSLEN_DURATION_MAX_NS (NTSC_HSLEN_DURATION_TYP_NS + 100)
+
+#define NTSC_HBP_DURATION_TYP_NS 4700
+
+/*
+ * I couldn't find the actual tolerance for the back porch, so let's
+ * just reuse the sync length ones.
+ */
+#define NTSC_HBP_DURATION_MIN_NS (NTSC_HBP_DURATION_TYP_NS - 100)
+#define NTSC_HBP_DURATION_MAX_NS (NTSC_HBP_DURATION_TYP_NS + 100)
+
+#define PAL_LINE_DURATION_NS 64000U
+#define PAL_LINES_NUMBER 625
+
+#define PAL_HACT_DURATION_TYP_NS 51950U
+#define PAL_HACT_DURATION_MIN_NS (PAL_HACT_DURATION_TYP_NS - 100)
+#define PAL_HACT_DURATION_MAX_NS (PAL_HACT_DURATION_TYP_NS + 400)
+
+#define PAL_HBLK_DURATION_TYP_NS (PAL_LINE_DURATION_NS -
PAL_HACT_DURATION_TYP_NS)
+#define PAL_HBLK_DURATION_MIN_NS (PAL_LINE_DURATION_NS -
PAL_HACT_DURATION_MAX_NS)
+#define PAL_HBLK_DURATION_MAX_NS (PAL_LINE_DURATION_NS -
PAL_HACT_DURATION_MIN_NS)
+
+#define PAL_HFP_DURATION_TYP_NS 1650
+#define PAL_HFP_DURATION_MIN_NS (PAL_HFP_DURATION_TYP_NS - 100)
+#define PAL_HFP_DURATION_MAX_NS (PAL_HFP_DURATION_TYP_NS + 400)
+
+#define PAL_HSLEN_DURATION_TYP_NS 4700
+#define PAL_HSLEN_DURATION_MIN_NS (PAL_HSLEN_DURATION_TYP_NS - 200)
+#define PAL_HSLEN_DURATION_MAX_NS (PAL_HSLEN_DURATION_TYP_NS + 200)
+
+#define PAL_HBP_DURATION_TYP_NS 5700
+#define PAL_HBP_DURATION_MIN_NS (PAL_HBP_DURATION_TYP_NS - 200)
+#define PAL_HBP_DURATION_MAX_NS (PAL_HBP_DURATION_TYP_NS + 200)
+
+#define PAL_VFP_INTERLACE_LINES 5
+#define PAL_VSLEN_INTERLACE_LINES 5
+
+#define PAL_SHORT_SYNC_DURATION_NS ((2 + 30) * NSEC_PER_USEC)
+#define PAL_LONG_SYNC_DURATION_NS ((30 + 2) * NSEC_PER_USEC)
+
+struct analog_param_field {
+ unsigned int even, odd;
+};
+
+#define PARAM_FIELD(_odd, _even) \
+ { .even = _even, .odd = _odd }
+
+struct analog_param_range {
+ unsigned int min, typ, max;
+};
+
+#define PARAM_RANGE(_min, _typ, _max) \
+ { .min = _min, .typ = _typ, .max = _max }
+
+struct analog_parameters {
+ unsigned int num_lines;
+ unsigned int line_duration_ns;
+
+ struct analog_param_range hact_ns;
+ struct analog_param_range hfp_ns;
+ struct analog_param_range hslen_ns;
+ struct analog_param_range hbp_ns;
+ struct analog_param_range hblk_ns;
+
+ struct analog_param_field vfp_lines;
+ struct analog_param_field vslen_lines;
+ struct analog_param_field vbp_lines;
+};
+
+#define TV_MODE_PARAMETER(_mode, _lines, _line_dur, _hact, _hfp, _hslen, _hbp,
_hblk, _vfp, _vslen, _vbp) \
+ [_mode] = { \
+ .num_lines = _lines, \
+ .line_duration_ns = _line_dur, \
+ .hact_ns = _hact, \
+ .hfp_ns = _hfp, \
+ .hslen_ns = _hslen, \
+ .hbp_ns = _hbp, \
+ .hblk_ns = _hblk, \
+ .vfp_lines = _vfp, \
+ .vslen_lines = _vslen, \
+ .vbp_lines = _vbp, \
+ }
+
+const static struct analog_parameters tv_modes_parameters[] = {
+ TV_MODE_PARAMETER(DRM_MODE_ANALOG_NTSC,
+ NTSC_LINES_NUMBER,
+ NTSC_LINE_DURATION_NS,
+ PARAM_RANGE(NTSC_HACT_DURATION_MIN_NS,
+ NTSC_HACT_DURATION_TYP_NS,
+ NTSC_HACT_DURATION_MAX_NS),
+ PARAM_RANGE(NTSC_HFP_DURATION_MIN_NS,
+ NTSC_HFP_DURATION_TYP_NS,
+ NTSC_HFP_DURATION_MAX_NS),
+ PARAM_RANGE(NTSC_HSLEN_DURATION_MIN_NS,
+ NTSC_HSLEN_DURATION_TYP_NS,
+ NTSC_HSLEN_DURATION_MAX_NS),
+ PARAM_RANGE(NTSC_HBP_DURATION_MIN_NS,
+ NTSC_HBP_DURATION_TYP_NS,
+ NTSC_HBP_DURATION_MAX_NS),
+ PARAM_RANGE(NTSC_HBLK_DURATION_MIN_NS,
+ NTSC_HBLK_DURATION_TYP_NS,
+ NTSC_HBLK_DURATION_MAX_NS),
+ PARAM_FIELD(3, 3),
+ PARAM_FIELD(3, 3),
+ PARAM_FIELD(3, 3)),
+ TV_MODE_PARAMETER(DRM_MODE_ANALOG_PAL,
+ PAL_LINES_NUMBER,
+ PAL_LINE_DURATION_NS,
+ PARAM_RANGE(PAL_HACT_DURATION_MIN_NS,
+ PAL_HACT_DURATION_TYP_NS,
+ PAL_HACT_DURATION_MAX_NS),
+ PARAM_RANGE(PAL_HFP_DURATION_MIN_NS,
+ PAL_HFP_DURATION_TYP_NS,
+ PAL_HFP_DURATION_MAX_NS),
+ PARAM_RANGE(PAL_HSLEN_DURATION_MIN_NS,
+ PAL_HSLEN_DURATION_TYP_NS,
+ PAL_HSLEN_DURATION_MAX_NS),
+ PARAM_RANGE(PAL_HBP_DURATION_MIN_NS,
+ PAL_HBP_DURATION_TYP_NS,
+ PAL_HBP_DURATION_MAX_NS),
+ PARAM_RANGE(PAL_HBLK_DURATION_MIN_NS,
+ PAL_HBLK_DURATION_TYP_NS,
+ PAL_HBLK_DURATION_MAX_NS),
+
+ /*
+ * The front porch is actually 6 short sync
+ * pulses for the even field, and 5 for the
+ * odd field. Each sync takes half a life so
+ * the odd field front porch is shorter by
+ * half a line.
+ *
+ * In progressive, we're supposed to use 6
+ * pulses, so we're fine there
+ */
+ PARAM_FIELD(3, 2),
+
+ /*
+ * The vsync length is 5 long sync pulses,
+ * each field taking half a line. We're
+ * shorter for both fields by half a line.
+ *
+ * In progressive, we're supposed to use 5
+ * pulses, so we're off by half
+ * a line.
+ *
+ * In interlace, we're now off by half a line
+ * for the even field and one line for the odd
+ * field.
+ */
+ PARAM_FIELD(3, 3),
+
+ /*
+ * The back porch is actually 5 short sync
+ * pulses for the even field, 4 for the odd
+ * field. In progressive, it's 5 short syncs.
+ *
+ * In progressive, we thus have 2.5 lines,
+ * plus the 0.5 line we were missing
+ * previously, so we should use 3 lines.
+ *
+ * In interlace, the even field is in the
+ * exact same case than progressive. For the
+ * odd field, we should be using 2 lines but
+ * we're one line short, so we'll make up for
+ * it here by using 3.
+ */
+ PARAM_FIELD(3, 3)),
+};
+
+static int fill_analog_mode(struct drm_display_mode *mode,
+ const struct analog_parameters *params,
+ unsigned long pixel_clock_hz,
+ unsigned int hactive,
+ unsigned int vactive,
+ bool interlace)
+{
+ unsigned long pixel_duration_ns = NSEC_PER_SEC / pixel_clock_hz;
+ unsigned long long htotal;
+ unsigned int vtotal;
+ unsigned int max_hact, hact_duration_ns;
+ unsigned int hblk, hblk_duration_ns;
+ unsigned int hfp, hfp_min, hfp_duration_ns;
+ unsigned int hslen, hslen_duration_ns;
+ unsigned int hbp, hbp_min, hbp_duration_ns;
+ unsigned int porches, porches_duration_ns;
+ unsigned int vfp, vfp_min;
+ unsigned int vbp, vbp_min;
+ unsigned int vslen;
+ int porches_rem;
+ bool strict = true;
+
+ max_hact = params->hact_ns.max / pixel_duration_ns;
+ if (pixel_clock_hz == 13500000 && hactive > max_hact &&
hactive <= 720)
+ strict = false;
+
+ /*
+ * Our pixel duration is going to be round down by the division,
+ * so rounding up is probably going to introduce even more
+ * deviation.
+ */
+ htotal = params->line_duration_ns * pixel_clock_hz / NSEC_PER_SEC;
+
+ hact_duration_ns = hactive * pixel_duration_ns;
+ if (strict &&
+ (hact_duration_ns < params->hact_ns.min ||
+ hact_duration_ns > params->hact_ns.max)) {
+ DRM_ERROR("Invalid horizontal active area duration: %uns (min: %u, max
%u)\n",
+ hact_duration_ns, params->hact_ns.min, params->hact_ns.max);
+ return -EINVAL;
+ }
+
+ hblk = htotal - hactive;
+ hblk_duration_ns = hblk * pixel_duration_ns;
+ if (strict &&
+ (hblk_duration_ns < params->hblk_ns.min ||
+ hblk_duration_ns > params->hblk_ns.max)) {
+ DRM_ERROR("Invalid horizontal blanking duration: %uns (min: %u, max
%u)\n",
+ hblk_duration_ns, params->hblk_ns.min, params->hblk_ns.max);
+ return -EINVAL;
+ }
+
+ hslen = DIV_ROUND_UP(params->hslen_ns.typ, pixel_duration_ns);
+ hslen_duration_ns = hslen * pixel_duration_ns;
+ if (strict &&
+ (hslen_duration_ns < params->hslen_ns.min ||
+ hslen_duration_ns > params->hslen_ns.max)) {
+ DRM_ERROR("Invalid horizontal sync duration: %uns (min: %u, max
%u)\n",
+ hslen_duration_ns, params->hslen_ns.min, params->hslen_ns.max);
+ return -EINVAL;
+ }
+
+ porches = hblk - hslen;
+ porches_duration_ns = porches * pixel_duration_ns;
+ if (strict &&
+ (porches_duration_ns > (params->hfp_ns.max + params->hbp_ns.max)
||
+ porches_duration_ns < (params->hfp_ns.min +
params->hbp_ns.min))) {
+ DRM_ERROR("Invalid horizontal porches duration: %uns\n",
porches_duration_ns);
+ return -EINVAL;
+ }
+
+ hfp_min = DIV_ROUND_UP(params->hfp_ns.min, pixel_duration_ns);
+ hbp_min = DIV_ROUND_UP(params->hbp_ns.min, pixel_duration_ns);
+ porches_rem = porches - hfp_min - hbp_min;
+
+ hfp = hfp_min + DIV_ROUND_UP(porches_rem, 2);
+ hfp_duration_ns = hfp * pixel_duration_ns;
+ if (strict &&
+ (hfp_duration_ns < params->hfp_ns.min ||
+ hfp_duration_ns > params->hfp_ns.max)) {
+ DRM_ERROR("Invalid horizontal front porch duration: %uns (min: %u, max
%u)\n",
+ hfp_duration_ns, params->hfp_ns.min, params->hfp_ns.max);
+ return -EINVAL;
+ }
+
+ hbp = porches - hfp;
+ hbp_duration_ns = hbp * pixel_duration_ns;
+ if (strict &&
+ (hbp_duration_ns < params->hbp_ns.min ||
+ hbp_duration_ns > params->hbp_ns.max)) {
+ DRM_ERROR("Invalid horizontal back porch duration: %uns (min: %u, max
%u)\n",
+ hbp_duration_ns, params->hbp_ns.min, params->hbp_ns.max);
+ return -EINVAL;
+ }
+
+ if (htotal != (hactive + hfp + hslen + hbp))
+ return -EINVAL;
+
+ mode->clock = pixel_clock_hz / 1000;
+ mode->hdisplay = hactive;
+ mode->hsync_start = hactive + hfp;
+ mode->hsync_end = hactive + hfp + hslen;
+ mode->htotal = hactive + hfp + hslen + hbp;
+
+ if (interlace) {
+ vfp_min = params->vfp_lines.even + params->vfp_lines.odd;
+ vbp_min = params->vbp_lines.even + params->vbp_lines.odd;
+ vslen = params->vslen_lines.even + params->vslen_lines.odd;
+ } else {
+ /*
+ * By convention, NSTC (aka 525/60) systems start with
+ * the even field, but PAL (aka 625/50) systems start
+ * with the odd one.
+ *
+ * PAL systems also have asymetric timings between the
+ * even and odd field, while NTSC is symetric.
+ *
+ * Moreover, if we want to create a progressive mode for
+ * PAL, we need to use the odd field timings.
+ *
+ * Since odd == even for NTSC, we can just use the odd
+ * one all the time to simplify the code a bit.
+ */
+ vfp_min = params->vfp_lines.odd;
+ vbp_min = params->vbp_lines.odd;
+ vslen = params->vslen_lines.odd;
+ }
+
+ porches = params->num_lines - vactive - vslen;
+ porches_rem = porches - vfp_min - vbp_min;
+
+ vfp = vfp_min + (porches_rem / 2);
+ vbp = porches - vfp;
+
+ vtotal = vactive + vfp + vslen + vbp;
+ if (params->num_lines != vtotal) {
+ DRM_ERROR("Invalid vertical total: %upx (expected %upx)\n",
+ vtotal, params->num_lines);
+ return -EINVAL;
+ }
+
+ mode->vdisplay = vactive;
+ mode->vsync_start = vactive + vfp;
+ mode->vsync_end = vactive + vfp + vslen;
+ mode->vtotal = vactive + vfp + vslen + vbp;
+
+ mode->type = DRM_MODE_TYPE_DRIVER;
+ mode->flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC;
+ if (interlace)
+ mode->flags |= DRM_MODE_FLAG_INTERLACE;
+
+ drm_mode_set_name(mode);
+
+ if (mode->vtotal != params->num_lines)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * drm_analog_tv_mode - create a display mode for an analog TV
+ * @dev: drm device
+ * @tv_mode: TV Mode standard to create a mode for. See DRM_MODE_TV_MODE_*.
+ * @pixel_clock_hz: Pixel Clock Frequency, in Hertz
+ * @hdisplay: hdisplay size
+ * @vdisplay: vdisplay size
+ * @interlace: whether to compute an interlaced mode
+ *
+ * This function creates a struct drm_display_mode instance suited for
+ * an analog TV output, for one of the usual analog TV mode.
+ *
+ * Note that @hdisplay is larger than the usual constraints for the PAL
+ * and NTSC timings, and we'll choose to ignore most timings constraints
+ * to reach those resolutions.
+ *
+ * Returns:
+ *
+ * A pointer to the mode, allocated with drm_mode_create(). Returns NULL
+ * on error.
+ */
+struct drm_display_mode *drm_analog_tv_mode(struct drm_device *dev,
+ enum drm_connector_tv_mode tv_mode,
+ unsigned long pixel_clock_hz,
+ unsigned int hdisplay,
+ unsigned int vdisplay,
+ bool interlace)
+{
+ struct drm_display_mode *mode;
+ enum drm_mode_analog analog;
+ int ret;
+
+ switch (tv_mode) {
+ case DRM_MODE_TV_MODE_NTSC_443:
+ fallthrough;
+ case DRM_MODE_TV_MODE_NTSC_J:
+ fallthrough;
+ case DRM_MODE_TV_MODE_NTSC_M:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_60:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_M:
+ fallthrough;
+ case DRM_MODE_TV_MODE_SECAM_60:
+ analog = DRM_MODE_ANALOG_NTSC;
+ break;
+
+ case DRM_MODE_TV_MODE_PAL_B:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_D:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_G:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_H:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_I:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_N:
+ fallthrough;
+ case DRM_MODE_TV_MODE_PAL_NC:
+ fallthrough;
+ case DRM_MODE_TV_MODE_SECAM_B:
+ fallthrough;
+ case DRM_MODE_TV_MODE_SECAM_D:
+ fallthrough;
+ case DRM_MODE_TV_MODE_SECAM_G:
+ fallthrough;
+ case DRM_MODE_TV_MODE_SECAM_K:
+ fallthrough;
+ case DRM_MODE_TV_MODE_SECAM_K1:
+ fallthrough;
+ case DRM_MODE_TV_MODE_SECAM_L:
+ analog = DRM_MODE_ANALOG_PAL;
+ break;
+
+ default:
+ return NULL;
+ }
+
+ mode = drm_mode_create(dev);
+ if (!mode)
+ return NULL;
+
+ ret = fill_analog_mode(mode,
+ &tv_modes_parameters[analog],
+ pixel_clock_hz, hdisplay, vdisplay, interlace);
+ if (ret)
+ goto err_free_mode;
+
+ return mode;
+
+err_free_mode:
+ drm_mode_destroy(dev, mode);
+ return NULL;
+}
+EXPORT_SYMBOL(drm_analog_tv_mode);
+
/**
* drm_cvt_mode -create a modeline based on the CVT algorithm
* @dev: drm device
diff --git a/drivers/gpu/drm/tests/Makefile b/drivers/gpu/drm/tests/Makefile
index b29ef1085cad..b22ac96fdd65 100644
--- a/drivers/gpu/drm/tests/Makefile
+++ b/drivers/gpu/drm/tests/Makefile
@@ -10,5 +10,6 @@ obj-$(CONFIG_DRM_KUNIT_TEST) += \
drm_framebuffer_test.o \
drm_kunit_helpers.o \
drm_mm_test.o \
+ drm_modes_test.o \
drm_plane_helper_test.o \
drm_rect_test.o
diff --git a/drivers/gpu/drm/tests/drm_modes_test.c
b/drivers/gpu/drm/tests/drm_modes_test.c
new file mode 100644
index 000000000000..87d398fcb99e
--- /dev/null
+++ b/drivers/gpu/drm/tests/drm_modes_test.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kunit test for drm_modes functions
+ */
+
+#include <kunit/test.h>
+
+#include <drm/drm_modes.h>
+
+#include "drm_kunit_helpers.h"
+
+struct drm_modes_test_priv {
+ struct drm_device *drm;
+};
+
+static int drm_modes_test_init(struct kunit *test)
+{
+ struct drm_modes_test_priv *priv;
+
+ priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ test->priv = priv;
+
+ priv->drm = drm_kunit_device_init("drm-modes-test");
+ if (IS_ERR(priv->drm))
+ return PTR_ERR(priv->drm);
+
+ return 0;
+}
+
+static void drm_modes_test_exit(struct kunit *test)
+{
+ struct drm_modes_test_priv *priv = test->priv;
+
+ drm_kunit_device_exit(priv->drm);
+}
+
+static void drm_modes_analog_tv_ntsc_480i(struct kunit *test)
+{
+ struct drm_modes_test_priv *priv = test->priv;
+ struct drm_display_mode *mode;
+
+ mode = drm_analog_tv_mode(priv->drm,
+ DRM_MODE_TV_MODE_NTSC_M,
+ 13500 * 1000, 720, 480,
+ true);
+ KUNIT_ASSERT_NOT_NULL(test, mode);
+
+ KUNIT_EXPECT_EQ(test, drm_mode_vrefresh(mode), 60);
+ KUNIT_EXPECT_EQ(test, mode->hdisplay, 720);
+
+ /* 63.556us * 13.5MHz = 858 pixels */
+ KUNIT_EXPECT_EQ(test, mode->htotal, 858);
+ KUNIT_EXPECT_EQ(test, mode->vdisplay, 480);
+ KUNIT_EXPECT_EQ(test, mode->vtotal, 525);
+}
+
+static void drm_modes_analog_tv_ntsc_480i_inlined(struct kunit *test)
+{
+ struct drm_modes_test_priv *priv = test->priv;
+ struct drm_display_mode *expected, *mode;
+
+ expected = drm_analog_tv_mode(priv->drm,
+ DRM_MODE_TV_MODE_NTSC_M,
+ 13500 * 1000, 720, 480,
+ true);
+ KUNIT_ASSERT_NOT_NULL(test, expected);
+
+ mode = drm_mode_analog_ntsc_480i(priv->drm);
+ KUNIT_ASSERT_NOT_NULL(test, mode);
+
+ KUNIT_EXPECT_TRUE(test, drm_mode_equal(expected, mode));
+}
+
+static void drm_modes_analog_tv_pal_576i(struct kunit *test)
+{
+ struct drm_modes_test_priv *priv = test->priv;
+ struct drm_display_mode *mode;
+
+ mode = drm_analog_tv_mode(priv->drm,
+ DRM_MODE_TV_MODE_PAL_B,
+ 13500 * 1000, 720, 576,
+ true);
+ KUNIT_ASSERT_NOT_NULL(test, mode);
+
+ KUNIT_EXPECT_EQ(test, drm_mode_vrefresh(mode), 50);
+ KUNIT_EXPECT_EQ(test, mode->hdisplay, 720);
+
+ /* 64us * 13.5MHz = 864 pixels */
+ KUNIT_EXPECT_EQ(test, mode->htotal, 864);
+ KUNIT_EXPECT_EQ(test, mode->vdisplay, 576);
+ KUNIT_EXPECT_EQ(test, mode->vtotal, 625);
+}
+
+static void drm_modes_analog_tv_pal_576i_inlined(struct kunit *test)
+{
+ struct drm_modes_test_priv *priv = test->priv;
+ struct drm_display_mode *expected, *mode;
+
+ expected = drm_analog_tv_mode(priv->drm,
+ DRM_MODE_TV_MODE_PAL_B,
+ 13500 * 1000, 720, 576,
+ true);
+ KUNIT_ASSERT_NOT_NULL(test, expected);
+
+ mode = drm_mode_analog_pal_576i(priv->drm);
+ KUNIT_ASSERT_NOT_NULL(test, mode);
+
+ KUNIT_EXPECT_TRUE(test, drm_mode_equal(expected, mode));
+}
+
+static struct kunit_case drm_modes_analog_tv_tests[] = {
+ KUNIT_CASE(drm_modes_analog_tv_ntsc_480i),
+ KUNIT_CASE(drm_modes_analog_tv_ntsc_480i_inlined),
+ KUNIT_CASE(drm_modes_analog_tv_pal_576i),
+ KUNIT_CASE(drm_modes_analog_tv_pal_576i_inlined),
+ { }
+};
+
+static struct kunit_suite drm_modes_analog_tv_test_suite = {
+ .name = "drm_modes_analog_tv",
+ .init = drm_modes_test_init,
+ .exit = drm_modes_test_exit,
+ .test_cases = drm_modes_analog_tv_tests,
+};
+
+kunit_test_suites(
+ &drm_modes_analog_tv_test_suite
+);
+MODULE_LICENSE("GPL v2");
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index a80ae9639e96..5ccf3d51d313 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -443,6 +443,23 @@ bool drm_mode_is_420_also(const struct drm_display_info
*display,
bool drm_mode_is_420(const struct drm_display_info *display,
const struct drm_display_mode *mode);
+struct drm_display_mode *drm_analog_tv_mode(struct drm_device *dev,
+ enum drm_connector_tv_mode mode,
+ unsigned long pixel_clock_hz,
+ unsigned int hdisplay,
+ unsigned int vdisplay,
+ bool interlace);
+
+static inline struct drm_display_mode *drm_mode_analog_ntsc_480i(struct
drm_device *dev)
+{
+ return drm_analog_tv_mode(dev, DRM_MODE_TV_MODE_NTSC_M, 13500000, 720, 480,
true);
+}
+
+static inline struct drm_display_mode *drm_mode_analog_pal_576i(struct
drm_device *dev)
+{
+ return drm_analog_tv_mode(dev, DRM_MODE_TV_MODE_PAL_B, 13500000, 720, 576,
true);
+}
+
struct drm_display_mode *drm_cvt_mode(struct drm_device *dev,
int hdisplay, int vdisplay, int vrefresh,
bool reduced, bool interlaced,
--
b4 0.10.0-dev-65ba7
Mateusz Kwiatkowski
2022-Aug-31 01:44 UTC
[Nouveau] [PATCH v2 10/41] drm/modes: Add a function to generate analog display modes
Hi Maxime, Wow. That's an enormous amount of effort put into this patch. But I'm tempted to say that this is actually overengineered quite a bit :D Considering that there's no way to access all these calculations from user space, and I can't imagine anybody using anything else than those standard 480i/576i (and maybe 240p/288p) modes at 13.5 MHz any time soon... I'm not sure if we actually need all this. But anyway, I'm not the maintainer of this subsystem, so I'm not the one to decide.> +enum drm_mode_analog { > +?? ?DRM_MODE_ANALOG_NTSC, > +?? ?DRM_MODE_ANALOG_PAL, > +};Using "NTSC" and "PAL" to describe the 50Hz and 60Hz analog TV modes is common, but strictly speaking a misnomer. Those are color encoding systems, and your patchset fully supports lesser used, but standard encodings for those (e.g. PAL-M for 60Hz and SECAM for 50Hz). I'd propose switching to some more neutral naming scheme. Some ideas: - DRM_MODE_ANALOG_60_HZ / DRM_MODE_ANALOG_50_HZ (after standard refresh rate) - DRM_MODE_ANALOG_525_LINES / DRM_MODE_ANALOG_625_LINES (after standard line ? count) - DRM_MODE_ANALOG_JM / DRM_MODE_ANALOG_BDGHIKLN (after corresponding ITU System ? Letter Designations)> +#define NTSC_HFP_DURATION_TYP_NS?? ?1500 > +#define NTSC_HFP_DURATION_MIN_NS?? ?1270 > +#define NTSC_HFP_DURATION_MAX_NS?? ?2220You've defined those min/typ/max ranges, but you're not using the "typ" field for anything other than hslen. The actual "typical" value is thus always the midpoint, which isn't necessarily the best choice. In particular, for the standard 720px wide modes at 13.5 MHz, hsync_start ends up being 735 for 480i and 734 for 576i, instead of 736 and 732 requested by BT.601. That's all obviously within tolerances, but the image ends up noticeably off-center (at least on modern TVs), especially in the 576i case.> +?? ?htotal = params->line_duration_ns * pixel_clock_hz / NSEC_PER_SEC;You're multiplying an unsigned int and an unsigned long - both types are only required to be 32 bit, so this is likely to overflow. You need to use a cast to unsigned long long, and then call do_div() for 64-bit division. This actually overflowed on me on my Pi running ARM32 kernel, resulting in negative horizontal porch lengths, and drm_helper_probe_add_cmdline_mode() taking over the mode generation (badly), and a horrible mess on screen.> +?? ?vfp = vfp_min + (porches_rem / 2); > +?? ?vbp = porches - vfp;Relative position of the vertical sync within the VBI effectively moves the image up and down. Adding that (porches_rem / 2) moves the image up off center by that many pixels. I'd keep the VFP always at minimum to keep the image centered. Best regards, Mateusz Kwiatkowski
Geert Uytterhoeven
2022-Aug-31 08:14 UTC
[Nouveau] [PATCH v2 10/41] drm/modes: Add a function to generate analog display modes
Hi Mateusz, On Wed, Aug 31, 2022 at 3:44 AM Mateusz Kwiatkowski <kfyatek at gmail.com> wrote:> Wow. That's an enormous amount of effort put into this patch. > > But I'm tempted to say that this is actually overengineered quite a bit :D > Considering that there's no way to access all these calculations from user > space, and I can't imagine anybody using anything else than those standard > 480i/576i (and maybe 240p/288p) modes at 13.5 MHz any time soon... I'm not > sure if we actually need all this.We'll need it when we get an Amiga DRM driver, which will use 7/14/28 MHz pixel clocks.> But anyway, I'm not the maintainer of this subsystem, so I'm not the one to > decide. > > > +enum drm_mode_analog { > > + DRM_MODE_ANALOG_NTSC, > > + DRM_MODE_ANALOG_PAL, > > +}; > > Using "NTSC" and "PAL" to describe the 50Hz and 60Hz analog TV modes is common, > but strictly speaking a misnomer. Those are color encoding systems, and your > patchset fully supports lesser used, but standard encodings for those (e.g. > PAL-M for 60Hz and SECAM for 50Hz). I'd propose switching to some more neutral > naming scheme. Some ideas: > > - DRM_MODE_ANALOG_60_HZ / DRM_MODE_ANALOG_50_HZ (after standard refresh rate) > - DRM_MODE_ANALOG_525_LINES / DRM_MODE_ANALOG_625_LINES (after standard line > count)IMHO these are bad names, as e.g. VGA640x480 at 60 is also analog, using 60 Hz and 525 lines. Add "TV" to the name?> - DRM_MODE_ANALOG_JM / DRM_MODE_ANALOG_BDGHIKLN (after corresponding ITU System > Letter Designations)Or DRM_MODE_ITU_*? But given the long list of letters, this looks fragile to me. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Maxime Ripard
2022-Sep-05 13:37 UTC
[Nouveau] [PATCH v2 10/41] drm/modes: Add a function to generate analog display modes
Hi, On Wed, Aug 31, 2022 at 03:44:52AM +0200, Mateusz Kwiatkowski wrote:> > +#define NTSC_HFP_DURATION_TYP_NS?? ?1500 > > +#define NTSC_HFP_DURATION_MIN_NS?? ?1270 > > +#define NTSC_HFP_DURATION_MAX_NS?? ?2220 > > You've defined those min/typ/max ranges, but you're not using the "typ" field > for anything other than hslen.Yeah... I've left most of them because it was so hard to find most of them, it's useful at least for documentation purposes. And it's a define so there's pretty much no downside to it as far as the final binary is involved.> The actual "typical" value is thus always the midpoint, which isn't > necessarily the best choice. > > In particular, for the standard 720px wide modes at 13.5 MHz, hsync_start > ends up being 735 for 480i and 734 for 576i, instead of 736 and 732 requested > by BT.601. That's all obviously within tolerances, but the image ends up > noticeably off-center (at least on modern TVs), especially in the 576i case.I'll try to fix that up.> > +?? ?htotal = params->line_duration_ns * pixel_clock_hz / NSEC_PER_SEC; > > You're multiplying an unsigned int and an unsigned long - both types are only > required to be 32 bit, so this is likely to overflow. You need to use a cast to > unsigned long long, and then call do_div() for 64-bit division. > > This actually overflowed on me on my Pi running ARM32 kernel, resulting in > negative horizontal porch lengths, and drm_helper_probe_add_cmdline_mode() > taking over the mode generation (badly), and a horrible mess on screen.Indeed, that's bad.> > +?? ?vfp = vfp_min + (porches_rem / 2); > > +?? ?vbp = porches - vfp; > > Relative position of the vertical sync within the VBI effectively moves the > image up and down. Adding that (porches_rem / 2) moves the image up off center > by that many pixels. I'd keep the VFP always at minimum to keep the image > centered.And you would increase the back porch only then? Maxime -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 228 bytes Desc: not available URL: <https://lists.freedesktop.org/archives/nouveau/attachments/20220905/e9dd4477/attachment.sig>