mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Johannes Schneider <johannes.schneider@leica-geosystems.com>
To: barebox@lists.infradead.org
Cc: thomas.haemmerle@leica-geosystems.com
Subject: [PATCH 1/6] clk: imx8mp: add 700 MHz rate entry for VIDEO_PLL1
Date: Tue,  2 Jun 2026 04:09:47 +0000	[thread overview]
Message-ID: <20260602040953.1060278-2-johannes.schneider@leica-geosystems.com> (raw)
In-Reply-To: <20260602040953.1060278-1-johannes.schneider@leica-geosystems.com>

From: Thomas Haemmerle <thomas.haemmerle@leica-geosystems.com>

The LVDS serializer requires link_freq = pixel_clock × 7.  For a 25 MHz
pixel clock the link frequency is 175 MHz.  VIDEO_PLL1 must be set to
700 MHz so the divider chain (VIDEO_PLL1 / 4 = 175 MHz) produces an
exact match; without it clk_set_rate() rounds down to 650 MHz, yielding
only 162.5 MHz and causing the LVDS transmitter to output ~743 pixels
per line instead of 800 — visible as a black strip on the right edge.

PLL parameters: Fin=24 MHz, P=3, S=2, K=0 → 24 × 350 / (3 × 4) = 700 MHz.

Assisted-by: Claude:claude-sonnet-4-6
Signed-of-by: Thomas Haemmerle <thomas.haemmerle@leica-geosystems.com>
---
 drivers/clk/imx/clk-pll14xx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clk/imx/clk-pll14xx.c b/drivers/clk/imx/clk-pll14xx.c
index 6716a6f555..db7e744e87 100644
--- a/drivers/clk/imx/clk-pll14xx.c
+++ b/drivers/clk/imx/clk-pll14xx.c
@@ -61,6 +61,7 @@ static const struct imx_pll14xx_rate_table imx_pll1416x_tbl[] = {
 };
 
 static const struct imx_pll14xx_rate_table imx_pll1443x_tbl[] = {
+	PLL_1443X_RATE(700000000U, 350, 3, 2, 0),
 	PLL_1443X_RATE(650000000U, 325, 3, 2, 0),
 	PLL_1443X_RATE(594000000U, 198, 2, 2, 0),
 	PLL_1443X_RATE(393216000U, 262, 2, 3, 9437),

base-commit: 81fbe2e8d0d445032498a0bfecf9fd270f00985a
-- 
2.43.0




  reply	other threads:[~2026-06-02  4:11 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-02  4:09 [PATCH 0/7] video: enable boot splash on i.MX8MP with LVDS panel Johannes Schneider
2026-06-02  4:09 ` Johannes Schneider [this message]
2026-06-02  7:04   ` [PATCH 1/6] clk: imx8mp: add 700 MHz rate entry for VIDEO_PLL1 Ahmad Fatoum
2026-06-02  4:09 ` [PATCH 2/6] pmdomain: imx8mp-blk-ctrl: add media blk-ctrl power domain support Johannes Schneider
2026-06-02  7:34   ` Ahmad Fatoum
2026-06-02  4:09 ` [PATCH 3/6] video: backlight-pwm: make power-supply and enable-gpio optional Johannes Schneider
2026-06-02  7:22   ` Ahmad Fatoum
2026-06-02  4:09 ` [PATCH 4/6] video: add i.MX8MP LCDIF2 V8 framebuffer driver Johannes Schneider
2026-06-02  7:16   ` Ahmad Fatoum
2026-06-04  3:34     ` SCHNEIDER Johannes
2026-06-02  4:09 ` [PATCH 5/6] video: add generic panel-lvds driver Johannes Schneider
2026-06-02  7:12   ` Ahmad Fatoum
2026-06-02  4:09 ` [PATCH 6/6] video: imx-lcdif: drain write-combine buffer before LCDIF DMA reads pixels Johannes Schneider
2026-06-02  8:12   ` Lucas Stach
2026-06-02  9:37     ` Ahmad Fatoum
2026-06-02 12:12       ` Lucas Stach
2026-06-02 15:17         ` Michael Grzeschik
2026-06-02 17:10         ` Michael Grzeschik
2026-06-04  3:42           ` SCHNEIDER Johannes

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260602040953.1060278-2-johannes.schneider@leica-geosystems.com \
    --to=johannes.schneider@leica-geosystems.com \
    --cc=barebox@lists.infradead.org \
    --cc=thomas.haemmerle@leica-geosystems.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox