All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Stefan Mätje" <stefan.maetje@esd.eu>
To: Jagan Teki <jagan@amarulasolutions.com>, u-boot@lists.denx.de
Cc: "Tom Rini" <trini@konsulko.com>, "Stefan Mätje" <stefan.maetje@esd.eu>
Subject: [PATCH 1/1] Fix wrong QSPI clock calculation for AM4372
Date: Tue, 30 Nov 2021 01:06:56 +0100	[thread overview]
Message-ID: <20211130000656.1837826-2-stefan.maetje@esd.eu> (raw)
In-Reply-To: <20211130000656.1837826-1-stefan.maetje@esd.eu>

On AM4372 the SPI_GCLK input gets its clock from the PRCM module which
divides the PER_CLKOUTM2 frequency (192MHz) by a fixed factor of 4.
See AM437x Reference Manual in section 27 QSPI >> 27.2 Integration.

The QSPI_FCLK therefore needs to take this factor into account and
becomes (192000000 / 4).

Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
---
 drivers/spi/ti_qspi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/ti_qspi.c b/drivers/spi/ti_qspi.c
index 664b9cad79..bccdeeaf82 100644
--- a/drivers/spi/ti_qspi.c
+++ b/drivers/spi/ti_qspi.c
@@ -25,7 +25,8 @@ DECLARE_GLOBAL_DATA_PTR;
 
 /* ti qpsi register bit masks */
 #define QSPI_TIMEOUT                    2000000
-#define QSPI_FCLK			192000000
+/* AM4372: QSPI gets SPI_GCLK from PRCM unit as PER_CLKOUTM2 divided by 4. */
+#define QSPI_FCLK                       (192000000 / 4)
 #define QSPI_DRA7XX_FCLK                76800000
 #define QSPI_WLEN_MAX_BITS		128
 #define QSPI_WLEN_MAX_BYTES		(QSPI_WLEN_MAX_BITS >> 3)
-- 
2.25.1


  reply	other threads:[~2021-11-30 13:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-30  0:06 [PATCH 0/1] Provide a fix for wrong QSPI clock calculation on AM4372 Stefan Mätje
2021-11-30  0:06 ` Stefan Mätje [this message]
2021-11-30  3:58   ` [PATCH 1/1] Fix wrong QSPI clock calculation for AM4372 Tom Rini
2021-11-30 12:14     ` Stefan Mätje
2021-11-30 12:51       ` Tom Rini
2022-01-17 18:36   ` Tom Rini

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=20211130000656.1837826-2-stefan.maetje@esd.eu \
    --to=stefan.maetje@esd.eu \
    --cc=jagan@amarulasolutions.com \
    --cc=trini@konsulko.com \
    --cc=u-boot@lists.denx.de \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.