According to SD host spec (Capabilities Register, offset 0x40<43:40>),
if timer count for retuning return 0xF, it means get information from other source.
Signed-off-by: Kevin Liu <kliu5@xxxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 8 ++++++++
drivers/mmc/host/sdhci.h | 1 +
2 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 3db5f10..20a3c53 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2970,6 +2970,14 @@ int sdhci_add_host(struct sdhci_host *host)
/* Initial value for re-tuning timer count */
host->tuning_count = (caps[1] & SDHCI_RETUNING_TIMER_COUNT_MASK) >>
SDHCI_RETUNING_TIMER_COUNT_SHIFT;
+ if (host->tuning_count == 0xF) {
+ if (host->ops->get_tuning_count)
+ host->tuning_count =
+ host->ops->get_tuning_count(host) & 0xF;
+ else
+ pr_err("%s: Hardware doesn't specify tuning count.\n",
+ mmc_hostname(mmc));
+ }
/*
* In case Re-tuning Timer is not disabled, the actual value of
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 7fe0462..8596f11 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -291,6 +291,7 @@ struct sdhci_ops {
void (*platform_resume)(struct sdhci_host *host);
void (*platform_init)(struct sdhci_host *host);
void (*signal_voltage_switch)(struct sdhci_host *host, u8 vol);
+ unsigned int (*get_tuning_count)(struct sdhci_host *host);
};
#ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
--
1.7.0.4
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