From c8d4a56082eebabbf96ddb86238808c30124f06b Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 17 Dec 2019 16:09:59 +0100 Subject: drm/mcde: Some fixes to handling video mode The video DSI mode had not really been tested. These fixes makes it more likely to work on real hardware: - Put the active width (x width) in the right bits and the VSA (vertical sync active) in the right bits (those were swapped). - Calculate the packet sizes in bytes as in the vendor driver, rather than in bits. Test the calculations agains a spreadsheet and confirmed by debug prints to be reasonable. - Also verified the register values with relative confidence to register dumps from the Samsung GT-I8190 boot loader graphics. We are not identical but not off by far either. - Error out if the current mode and refresh frequency doesn't work out. (In the future we may simply want to scale down the vrefresh.) - Handle negative result in front/back/sync packages and fall back to zero like in the vendor driver. - Put in lots of clarifying comments and references to the documentation where the code is hard to understand. - Set the DSI_VID_VCA_SETTING2 field DSI_VID_VCA_SETTING2_MAX_LINE_LIMIT to blkline_pck - 6 as in the vendor driver and mask the field properly. - Set the DSI_VID_VCA_SETTING1 field DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT to blkeol_pck - 6 to blkeol_duration - 6 as in the vendor driver. Cc: Stephan Gerhold Fixes: 5fc537bfd000 ("drm/mcde: Add new driver for ST-Ericsson MCDE") Link: https://patchwork.freedesktop.org/patch/msgid/20191217150959.17215-1-linus.walleij@linaro.org Reviewed-by: Stephan Gerhold Signed-off-by: Linus Walleij --- drivers/gpu/drm/mcde/mcde_dsi.c | 239 ++++++++++++++++++++++++++++------- drivers/gpu/drm/mcde/mcde_dsi_regs.h | 1 + 2 files changed, 192 insertions(+), 48 deletions(-) (limited to 'drivers/gpu/drm/mcde') diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c index 42fff811653e..32e94bcb4a69 100644 --- a/drivers/gpu/drm/mcde/mcde_dsi.c +++ b/drivers/gpu/drm/mcde/mcde_dsi.c @@ -388,13 +388,14 @@ void mcde_dsi_te_request(struct mipi_dsi_device *mdsi) static void mcde_dsi_setup_video_mode(struct mcde_dsi *d, const struct drm_display_mode *mode) { - u8 bpp = mipi_dsi_pixel_format_to_bpp(d->mdsi->format); + /* cpp, characters per pixel, number of bytes per pixel */ + u8 cpp = mipi_dsi_pixel_format_to_bpp(d->mdsi->format) / 8; + u64 pclk; u64 bpl; - u32 hfp; - u32 hbp; - u32 hsa; + int hfp; + int hbp; + int hsa; u32 blkline_pck, line_duration; - u32 blkeol_pck, blkeol_duration; u32 val; val = 0; @@ -431,11 +432,21 @@ static void mcde_dsi_setup_video_mode(struct mcde_dsi *d, return; } - /* TODO: TVG could be enabled here */ + /* TODO: TVG (test video generator) could be enabled here */ - /* Send blanking packet */ + /* + * During vertical blanking: go to LP mode + * Like with the EOL setting, if this is not set, the EOL area will be + * filled with NULL or blanking packets in the vblank area. + * FIXME: some Samsung phones and display panels such as s6e63m0 use + * DSI_VID_MAIN_CTL_REG_BLKLINE_MODE_BLANKING here instead, + * figure out how to properly configure that from the panel. + */ val |= DSI_VID_MAIN_CTL_REG_BLKLINE_MODE_LP_0; - /* Send EOL packet */ + /* + * During EOL: go to LP mode. If this is not set, the EOL area will be + * filled with NULL or blanking packets. + */ val |= DSI_VID_MAIN_CTL_REG_BLKEOL_MODE_LP_0; /* Recovery mode 1 */ val |= 1 << DSI_VID_MAIN_CTL_RECOVERY_MODE_SHIFT; @@ -443,13 +454,13 @@ static void mcde_dsi_setup_video_mode(struct mcde_dsi *d, writel(val, d->regs + DSI_VID_MAIN_CTL); /* Vertical frame parameters are pretty straight-forward */ - val = mode->vdisplay << DSI_VID_VSIZE_VSA_LENGTH_SHIFT; + val = mode->vdisplay << DSI_VID_VSIZE_VACT_LENGTH_SHIFT; /* vertical front porch */ val |= (mode->vsync_start - mode->vdisplay) << DSI_VID_VSIZE_VFP_LENGTH_SHIFT; /* vertical sync active */ val |= (mode->vsync_end - mode->vsync_start) - << DSI_VID_VSIZE_VACT_LENGTH_SHIFT; + << DSI_VID_VSIZE_VSA_LENGTH_SHIFT; /* vertical back porch */ val |= (mode->vtotal - mode->vsync_end) << DSI_VID_VSIZE_VBP_LENGTH_SHIFT; @@ -457,36 +468,54 @@ static void mcde_dsi_setup_video_mode(struct mcde_dsi *d, /* * Horizontal frame parameters: - * horizontal resolution is given in pixels and must be re-calculated - * into bytes since this is what the hardware expects. + * horizontal resolution is given in pixels but must be re-calculated + * into bytes since this is what the hardware expects, these registers + * define the payload size of the packet. + * + * hfp = horizontal front porch in bytes + * hbp = horizontal back porch in bytes + * hsa = horizontal sync active in bytes * * 6 + 2 is HFP header + checksum */ - hfp = (mode->hsync_start - mode->hdisplay) * bpp - 6 - 2; + hfp = (mode->hsync_start - mode->hdisplay) * cpp - 6 - 2; if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) { /* + * Use sync pulse for sync: explicit HSA time * 6 is HBP header + checksum * 4 is RGB header + checksum */ - hbp = (mode->htotal - mode->hsync_end) * bpp - 4 - 6; + hbp = (mode->htotal - mode->hsync_end) * cpp - 4 - 6; /* * 6 is HBP header + checksum * 4 is HSW packet bytes * 4 is RGB header + checksum */ - hsa = (mode->hsync_end - mode->hsync_start) * bpp - 4 - 4 - 6; + hsa = (mode->hsync_end - mode->hsync_start) * cpp - 4 - 4 - 6; } else { /* - * HBP includes both back porch and sync + * Use event for sync: HBP includes both back porch and sync * 6 is HBP header + checksum * 4 is HSW packet bytes * 4 is RGB header + checksum */ - hbp = (mode->htotal - mode->hsync_start) * bpp - 4 - 4 - 6; - /* HSA is not considered in this mode and set to 0 */ + hbp = (mode->htotal - mode->hsync_start) * cpp - 4 - 4 - 6; + /* HSA is not present in this mode and set to 0 */ + hsa = 0; + } + if (hfp < 0) { + dev_info(d->dev, "hfp negative, set to 0\n"); + hfp = 0; + } + if (hbp < 0) { + dev_info(d->dev, "hbp negative, set to 0\n"); + hbp = 0; + } + if (hsa < 0) { + dev_info(d->dev, "hsa negative, set to 0\n"); hsa = 0; } - dev_dbg(d->dev, "hfp: %u, hbp: %u, hsa: %u\n", + dev_dbg(d->dev, "hfp: %u, hbp: %u, hsa: %u bytes\n", hfp, hbp, hsa); /* Frame parameters: horizontal sync active */ @@ -497,71 +526,185 @@ static void mcde_dsi_setup_video_mode(struct mcde_dsi *d, val |= hfp << DSI_VID_HSIZE1_HFP_LENGTH_SHIFT; writel(val, d->regs + DSI_VID_HSIZE1); - /* RGB data length (bytes on one scanline) */ - val = mode->hdisplay * (bpp / 8); + /* RGB data length (visible bytes on one scanline) */ + val = mode->hdisplay * cpp; writel(val, d->regs + DSI_VID_HSIZE2); + dev_dbg(d->dev, "RGB length, visible area on a line: %u bytes\n", val); - /* TODO: further adjustments for TVG mode here */ + /* + * Calculate the time between two pixels in picoseconds using + * the supplied refresh rate and total resolution including + * porches and sync. + */ + /* (ps/s) / (pixels/s) = ps/pixels */ + pclk = DIV_ROUND_UP_ULL(1000000000000, + (mode->vrefresh * mode->htotal * mode->vtotal)); + dev_dbg(d->dev, "picoseconds between two pixels: %llu\n", + pclk); /* - * EOL packet length from bits per line calculations: pixel clock - * is given in kHz, calculate the time between two pixels in - * picoseconds. + * How many bytes per line will this update frequency yield? + * + * Calculate the number of picoseconds for one scanline (1), then + * divide by 1000000000000 (2) to get in pixels per second we + * want to output. + * + * Multiply with number of bytes per second at this video display + * frequency (3) to get number of bytes transferred during this + * time. Notice that we use the frequency the display wants, + * not what we actually get from the DSI PLL, which is hs_freq. + * + * These arithmetics are done in a different order to avoid + * overflow. */ - bpl = mode->clock * mode->htotal; - bpl *= (d->hs_freq / 8); - do_div(bpl, 1000000); /* microseconds */ - do_div(bpl, 1000000); /* seconds */ + bpl = pclk * mode->htotal; /* (1) picoseconds per line */ + dev_dbg(d->dev, "picoseconds per line: %llu\n", bpl); + /* Multiply with bytes per second (3) */ + bpl *= (d->mdsi->hs_rate / 8); + /* Pixels per second (2) */ + bpl = DIV_ROUND_DOWN_ULL(bpl, 1000000); /* microseconds */ + bpl = DIV_ROUND_DOWN_ULL(bpl, 1000000); /* seconds */ + /* parallel transactions in all lanes */ bpl *= d->mdsi->lanes; - dev_dbg(d->dev, "calculated bytes per line: %llu\n", bpl); + dev_dbg(d->dev, + "calculated bytes per line: %llu @ %d Hz with HS %lu Hz\n", + bpl, mode->vrefresh, d->mdsi->hs_rate); + /* * 6 is header + checksum, header = 4 bytes, checksum = 2 bytes * 4 is short packet for vsync/hsync */ if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) { - /* Fixme: isn't the hsync width in pixels? */ + /* Set the event packet size to 0 (not used) */ + writel(0, d->regs + DSI_VID_BLKSIZE1); + /* + * FIXME: isn't the hsync width in pixels? The porch and + * sync area size is in pixels here, but this -6 + * seems to be for bytes. It looks like this in the vendor + * code though. Is it completely untested? + */ blkline_pck = bpl - (mode->hsync_end - mode->hsync_start) - 6; val = blkline_pck << DSI_VID_BLKSIZE2_BLKLINE_PULSE_PCK_SHIFT; writel(val, d->regs + DSI_VID_BLKSIZE2); } else { + /* Set the sync pulse packet size to 0 (not used) */ + writel(0, d->regs + DSI_VID_BLKSIZE2); + /* Specifying payload size in bytes (-4-6 from manual) */ blkline_pck = bpl - 4 - 6; + if (blkline_pck > 0x1FFF) + dev_err(d->dev, "blkline_pck too big %d bytes\n", + blkline_pck); val = blkline_pck << DSI_VID_BLKSIZE1_BLKLINE_EVENT_PCK_SHIFT; + val &= DSI_VID_BLKSIZE1_BLKLINE_EVENT_PCK_MASK; writel(val, d->regs + DSI_VID_BLKSIZE1); } - line_duration = (blkline_pck + 6) / d->mdsi->lanes; - dev_dbg(d->dev, "line duration %u\n", line_duration); + /* + * The line duration is used to scale back the frequency from + * the max frequency supported by the HS clock to the desired + * update frequency in vrefresh. + */ + line_duration = blkline_pck + 6; + /* + * The datasheet contains this complex condition to decreasing + * the line duration by 1 under very specific circumstances. + * Here we also imply that LP is used during burst EOL. + */ + if (d->mdsi->lanes == 2 && (hsa & 0x01) && (hfp & 0x01) + && (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)) + line_duration--; + line_duration = DIV_ROUND_CLOSEST(line_duration, d->mdsi->lanes); + dev_dbg(d->dev, "line duration %u bytes\n", line_duration); val = line_duration << DSI_VID_DPHY_TIME_REG_LINE_DURATION_SHIFT; /* * This is the time to perform LP->HS on D-PHY * FIXME: nowhere to get this from: DT property on the DSI? + * The manual says this is "system dependent". + * values like 48 and 72 seen in the vendor code. */ - val |= 0 << DSI_VID_DPHY_TIME_REG_WAKEUP_TIME_SHIFT; + val |= 48 << DSI_VID_DPHY_TIME_REG_WAKEUP_TIME_SHIFT; writel(val, d->regs + DSI_VID_DPHY_TIME); - /* Calculate block end of line */ - blkeol_pck = bpl - mode->hdisplay * bpp - 6; - blkeol_duration = (blkeol_pck + 6) / d->mdsi->lanes; - dev_dbg(d->dev, "blkeol pck: %u, duration: %u\n", - blkeol_pck, blkeol_duration); - + /* + * See the manual figure 657 page 2203 for understanding the impact + * of the different burst mode settings. + */ if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) { - /* Set up EOL clock for burst mode */ + int blkeol_pck, blkeol_duration; + /* + * Packet size at EOL for burst mode, this is only used + * if DSI_VID_MAIN_CTL_REG_BLKEOL_MODE_LP_0 is NOT set, + * but we instead send NULL or blanking packets at EOL. + * This is given in number of bytes. + * + * See the manual page 2198 for the 13 reg_blkeol_pck bits. + */ + blkeol_pck = bpl - (mode->htotal * cpp) - 6; + if (blkeol_pck < 0) { + dev_err(d->dev, "video block does not fit on line!\n"); + dev_err(d->dev, + "calculated bytes per line: %llu @ %d Hz\n", + bpl, mode->vrefresh); + dev_err(d->dev, + "bytes per line (blkline_pck) %u bytes\n", + blkline_pck); + dev_err(d->dev, + "blkeol_pck becomes %d bytes\n", blkeol_pck); + return; + } + dev_dbg(d->dev, "BLKEOL packet: %d bytes\n", blkeol_pck); + val = readl(d->regs + DSI_VID_BLKSIZE1); + val &= ~DSI_VID_BLKSIZE1_BLKEOL_PCK_MASK; val |= blkeol_pck << DSI_VID_BLKSIZE1_BLKEOL_PCK_SHIFT; writel(val, d->regs + DSI_VID_BLKSIZE1); - writel(blkeol_pck, d->regs + DSI_VID_VCA_SETTING2); - - writel(blkeol_duration, d->regs + DSI_VID_PCK_TIME); - writel(blkeol_duration - 6, d->regs + DSI_VID_VCA_SETTING1); + /* Use the same value for exact burst limit */ + val = blkeol_pck << + DSI_VID_VCA_SETTING2_EXACT_BURST_LIMIT_SHIFT; + val &= DSI_VID_VCA_SETTING2_EXACT_BURST_LIMIT_MASK; + writel(val, d->regs + DSI_VID_VCA_SETTING2); + /* + * This BLKEOL duration is claimed to be the duration in clock + * cycles of the BLLP end-of-line (EOL) period for each line if + * DSI_VID_MAIN_CTL_REG_BLKEOL_MODE_LP_0 is set. + * + * It is hard to trust the manuals' claim that this is in clock + * cycles as we mimic the behaviour of the vendor code, which + * appears to write a number of bytes that would have been + * transferred on a single lane. + * + * See the manual figure 657 page 2203 and page 2198 for the 13 + * reg_blkeol_duration bits. + * + * FIXME: should this also be set up also for non-burst mode + * according to figure 565 page 2202? + */ + blkeol_duration = DIV_ROUND_CLOSEST(blkeol_pck + 6, + d->mdsi->lanes); + dev_dbg(d->dev, "BLKEOL duration: %d clock cycles\n", + blkeol_duration); + + val = readl(d->regs + DSI_VID_PCK_TIME); + val &= ~DSI_VID_PCK_TIME_BLKEOL_DURATION_MASK; + val |= blkeol_duration << + DSI_VID_PCK_TIME_BLKEOL_DURATION_SHIFT; + writel(val, d->regs + DSI_VID_PCK_TIME); + + /* Max burst limit, this is given in bytes */ + val = readl(d->regs + DSI_VID_VCA_SETTING1); + val &= ~DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT_MASK; + val |= (blkeol_pck - 6) << + DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT_SHIFT; + writel(val, d->regs + DSI_VID_VCA_SETTING1); } /* Maximum line limit */ val = readl(d->regs + DSI_VID_VCA_SETTING2); - val |= blkline_pck << - DSI_VID_VCA_SETTING2_EXACT_BURST_LIMIT_SHIFT; + val &= ~DSI_VID_VCA_SETTING2_MAX_LINE_LIMIT_MASK; + val |= (blkline_pck - 6) << + DSI_VID_VCA_SETTING2_MAX_LINE_LIMIT_SHIFT; writel(val, d->regs + DSI_VID_VCA_SETTING2); - + dev_dbg(d->dev, "blkline pck: %d bytes\n", blkline_pck - 6); } static void mcde_dsi_start(struct mcde_dsi *d) diff --git a/drivers/gpu/drm/mcde/mcde_dsi_regs.h b/drivers/gpu/drm/mcde/mcde_dsi_regs.h index 8089db805c57..16551af1089e 100644 --- a/drivers/gpu/drm/mcde/mcde_dsi_regs.h +++ b/drivers/gpu/drm/mcde/mcde_dsi_regs.h @@ -228,6 +228,7 @@ #define DSI_VID_PCK_TIME 0x000000A8 #define DSI_VID_PCK_TIME_BLKEOL_DURATION_SHIFT 0 +#define DSI_VID_PCK_TIME_BLKEOL_DURATION_MASK 0x00000FFF #define DSI_VID_DPHY_TIME 0x000000AC #define DSI_VID_DPHY_TIME_REG_LINE_DURATION_SHIFT 0 -- cgit v1.2.3