[RFC PATCH 05/13] drivers: mmc: host: sdhci_am654: Fix ITAPDLY for HS400 timing

From: Judith Mendez
Date: Tue Jan 30 2024 - 19:37:39 EST


While STRB is currently used for DATA and CRC responses, the CMD
responses from the device to the host still require ITAPDLY for
HS400 timing.

Currently what is stored for HS400 is the ITAPDLY from High Speed
mode which is incorrect. The ITAPDLY for HS400 speed mode should
be the same as ITAPDLY as HS200 timing after tuning is executed.
Add the functionality to save ITAPDLY from HS200 tuning and save
as HS400 ITAPDLY.

Signed-off-by: Judith Mendez <jm@xxxxxx>
---
drivers/mmc/host/sdhci_am654.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index 61f95aad3f80..0f0178936a6d 100644
--- a/drivers/mmc/host/sdhci_am654.c
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -151,6 +151,7 @@ struct sdhci_am654_data {
u32 flags;
u32 quirks;
bool dll_enable;
+ bool hs200_tunning;

#define SDHCI_AM654_QUIRK_FORCE_CDTEST BIT(0)
};
@@ -252,6 +253,10 @@ static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned int clock,
return;
}

+ /* HS400 ITAPDLY should be the same as HS200 ITAPDLY*/
+ if (timing == MMC_TIMING_MMC_HS400)
+ sdhci_am654->itap_del_sel[timing] = sdhci_am654->itap_del_sel[timing - 1];
+
sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
sdhci_am654->itap_del_ena[timing]);
}
@@ -311,6 +316,9 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)

regmap_update_bits(sdhci_am654->base, PHY_CTRL5, CLKBUFSEL_MASK,
sdhci_am654->clkbuf_sel);
+
+ if (timing == MMC_TIMING_MMC_HS200 && sdhci_am654->dll_enable)
+ sdhci_am654->hs200_tunning = true;
}

static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
@@ -543,6 +551,10 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,

sdhci_am654_write_itapdly(sdhci_am654, itap, 1);

+ /* Save ITAPDLY for HS200 */
+ if (sdhci_am654->hs200_tunning)
+ sdhci_am654->itap_del_sel[MMC_TIMING_MMC_HS200] = itap;
+
return 0;
}

--
2.34.1