[v2,2/5] mmc: sdhci: add function to get retunig timer count

Commit Message

Kevin Liu Jan. 29, 2013, 9:41 a.m. UTC

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. If driver didn't provide the function in case timer count
return 0xF, just disable retuning.

Signed-off-by: Kevin Liu <[e-mail]>
Reviewed-by: Aaron Lu <[e-mail]>
---
 drivers/mmc/host/sdhci.c |   10 ++++++++++
 drivers/mmc/host/sdhci.h |    1 +
 2 files changed, 11 insertions(+)

Patch

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 8a14927..46753a3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2945,6 +2945,16 @@  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));
+			host->tuning_count = 0;
+		}
+	}
 
 	/*
 	 * 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 c8d11b9..4a65dbe 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -282,6 +282,7 @@  struct sdhci_ops {
 	void	(*platform_resume)(struct sdhci_host *host);
 	void    (*adma_workaround)(struct sdhci_host *host, u32 intmask);
 	void	(*platform_init)(struct sdhci_host *host);
+	unsigned int    (*get_tuning_count)(struct sdhci_host *host);
 };
 
 #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS