[PATCH V11 3/4] mmc: sdhci: Add ADMA3 DMA support for V4 enabled host

Sowjanya Komatineni
2019-01-23T19:30:53Z

Below are the supported DMA types in Host Control1 Register
with Version 4 enable
b'00 - SDMA
b'01 - Not Used
b'10 - ADMA2
b'11 - ADMA2 or ADMA3

ADMA3 uses Command Descriptor to issue an SD command.
A multi-block data transfer is performed by using a pair of CMD
descriptor and ADMA2 descriptor.

ADMA3 performs multiple of multi-block data transfer by using
Integrated Descriptor which is more suitable for Command Queuing
to fetch both Command and Transfer descriptors.

Host Capabilities register indicates the supports of ADMA3 DMA.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
---
[V11]: Fixed typo in commit message of this patch.
[V10]: Changes are same as V9 except this series has SDHCI core changes
into seperate patch

drivers/mmc/host/sdhci.c | 9 ++++++++-
drivers/mmc/host/sdhci.h | 2 ++
2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a22e11a65658..c6afe793399e 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3353,7 +3353,14 @@ void sdhci_cqe_enable(struct mmc_host *mmc)

ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
ctrl &= ~SDHCI_CTRL_DMA_MASK;
- if (host->flags & SDHCI_USE_64_BIT_DMA)
+ /*
+ * Host from V4.10 supports ADMA3 DMA type.
+ * ADMA3 performs integrated descriptor which is more suitable
+ * for cmd queuing to fetch both command and transfer descriptors.
+ */
+ if (host->v4_mode && (host->caps1 & SDHCI_CAN_DO_ADMA3))
+ ctrl |= SDHCI_CTRL_ADMA3;
+ else if (host->flags & SDHCI_USE_64_BIT_DMA)
ctrl |= SDHCI_CTRL_ADMA64;
else
ctrl |= SDHCI_CTRL_ADMA32;
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 6cc9a3c2ac66..4070be49d947 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -88,6 +88,7 @@
#define SDHCI_CTRL_ADMA1 0x08
#define SDHCI_CTRL_ADMA32 0x10
#define SDHCI_CTRL_ADMA64 0x18
+#define SDHCI_CTRL_ADMA3 0x18
#define SDHCI_CTRL_8BITBUS 0x20
#define SDHCI_CTRL_CDTEST_INS 0x40
#define SDHCI_CTRL_CDTEST_EN 0x80
@@ -230,6 +231,7 @@
#define SDHCI_RETUNING_MODE_SHIFT 14
#define SDHCI_CLOCK_MUL_MASK 0x00FF0000
#define SDHCI_CLOCK_MUL_SHIFT 16
+#define SDHCI_CAN_DO_ADMA3 0x08000000
#define SDHCI_SUPPORT_HS400 0x80000000 /* Non-standard */

#define SDHCI_CAPABILITIES_1 0x44
--
2.7.4