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From: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
To: <u-boot@lists.denx.de>
Cc: <peng.fan@nxp.com>, <jh80.chung@samsung.com>, <git@amd.com>
Subject: [PATCH] mmc: Change the frequency to MMC_HS_52 when selecting hs400
Date: Tue, 23 Apr 2024 11:00:57 +0530	[thread overview]
Message-ID: <20240423053057.15863-1-venkatesh.abbarapu@amd.com> (raw)

Per JESD84-B51 P47, host need to change frequency to <=52MHz
after setting HS_TIMING to 0x1, and host need to set the
8-bit DDR buswidth. Currently setting the frequency to 26MHz
and trying to switch 8-bit DDR buswidth resulting timeouts.

mmc dev 1 0
Select HS400 failed -110
switch to partitions #0, OK
mmc1(part 0) is current device

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
---
 drivers/mmc/mmc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 7b068c71ff..a2ed99aefe 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -962,8 +962,8 @@ static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode,
 	 * Extended CSD. Reconfigure the controller to run at HS mode.
 	 */
 	if (hsdowngrade) {
-		mmc_select_mode(mmc, MMC_HS);
-		mmc_set_clock(mmc, mmc_mode2freq(mmc, MMC_HS), false);
+		mmc_select_mode(mmc, MMC_HS_52);
+		mmc_set_clock(mmc, mmc_mode2freq(mmc, MMC_HS_52), false);
 	}
 #endif
 
@@ -2043,7 +2043,7 @@ static int mmc_select_hs400(struct mmc *mmc)
 	}
 
 	/* Set back to HS */
-	mmc_set_card_speed(mmc, MMC_HS, true);
+	mmc_set_card_speed(mmc, MMC_HS_52, true);
 
 	err = mmc_hs400_prepare_ddr(mmc);
 	if (err)
-- 
2.17.1


             reply	other threads:[~2024-04-23  5:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-23  5:30 Venkatesh Yadav Abbarapu [this message]
2024-05-07  4:16 ` [PATCH] mmc: Change the frequency to MMC_HS_52 when selecting hs400 Abbarapu, Venkatesh

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