mmc: sdhci: add support for retuning mode 1

Host Controller v3.00 can support retuning modes 1,2 or 3 depending on
the bits 46-47 of the Capabilities register. Also, the timer count for
retuning is indicated by bits 40-43 of the same register. We initialize
timer_list for retuning the first time we execute tuning procedure. This
condition is indicated by SDHCI_NEEDS_RETUNING not being set. Since
retuning mode 1 sets a limit of 4MB on the maximum data length, we set
max_blk_count appropriately. Once the tuning timer expires, we set
SDHCI_NEEDS_RETUNING flag, and if the flag is set, we execute tuning
procedure before sending the next command. We need to restore mmc_request
structure after executing retuning procedure since host->mrq is used
inside the procedure to send CMD19. We also disable and re-enable this
flag during suspend and resume respectively, as per the spec v3.00.

Tested by Zhangfei Gao with a Toshiba uhs card and general hs card,
on mmp2 in SDMA mode.

Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Reviewed-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
Acked-by: Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index a88a799ed7c3..e902618d68f4 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -112,6 +112,7 @@ struct sdhci_host {
 #define SDHCI_REQ_USE_DMA       (1<<2)  /* Use DMA for this req. */
 #define SDHCI_DEVICE_DEAD       (1<<3)  /* Device unresponsive */
 #define SDHCI_SDR50_NEEDS_TUNING (1<<4) /* SDR50 needs tuning */
+#define SDHCI_NEEDS_RETUNING    (1<<5)  /* Host needs retuning */
 
         unsigned int version;   /* SDHCI spec. version */
 
@@ -152,6 +153,11 @@ struct sdhci_host {
         wait_queue_head_t       buf_ready_int;  /* Waitqueue for Buffer Read Ready interrupt */
         unsigned int            tuning_done;    /* Condition flag set when CMD19 succeeds */
 
+        unsigned int            tuning_count;   /* Timer count for re-tuning */
+        unsigned int            tuning_mode;    /* Re-tuning mode supported by host */
+#define SDHCI_TUNING_MODE_1     0
+        struct timer_list       tuning_timer;   /* Timer for tuning */
+
         unsigned long private[0] ____cacheline_aligned;
 };
 #endif /* __SDHCI_H */