[PATCH V8 5/9] mmc: sdhci: Add 32-bit block count support for v4 mode

From: Chunyan Zhang
Date: Thu Aug 30 2018 - 04:22:23 EST


Host Controller Version 4.10 re-defines SDMA System Address register
as 32-bit Block Count for v4 mode, and SDMA uses ADMA System
Address register (05Fh-058h) instead if v4 mode is enabled. Also
when using 32-bit block count, 16-bit block count register need
to be set to zero.

Since using 32-bit Block Count would cause problems for auto-cmd23,
it can be chosen via host->quirk2.

Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 14 +++++++++++++-
drivers/mmc/host/sdhci.h | 8 ++++++++
2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 17345b6..604bf4c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1073,7 +1073,19 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
/* Set the DMA boundary value and block size */
sdhci_writew(host, SDHCI_MAKE_BLKSZ(host->sdma_boundary, data->blksz),
SDHCI_BLOCK_SIZE);
- sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
+
+ /*
+ * For Version 4.10 onwards, if v4 mode is enabled, 32-bit Block Count
+ * can be supported, in that case 16-bit block count register must be 0.
+ */
+ if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
+ (host->quirks2 & SDHCI_QUIRK2_USE_32BIT_BLK_CNT)) {
+ if (sdhci_readw(host, SDHCI_BLOCK_COUNT))
+ sdhci_writew(host, 0, SDHCI_BLOCK_COUNT);
+ sdhci_writew(host, data->blocks, SDHCI_32BIT_BLK_CNT);
+ } else {
+ sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
+ }
}

static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index c5cc513..f7a1079 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -28,6 +28,7 @@

#define SDHCI_DMA_ADDRESS 0x00
#define SDHCI_ARGUMENT2 SDHCI_DMA_ADDRESS
+#define SDHCI_32BIT_BLK_CNT SDHCI_DMA_ADDRESS

#define SDHCI_BLOCK_SIZE 0x04
#define SDHCI_MAKE_BLKSZ(dma, blksz) (((dma & 0x7) << 12) | (blksz & 0xFFF))
@@ -462,6 +463,13 @@ struct sdhci_host {
* obtainable timeout.
*/
#define SDHCI_QUIRK2_DISABLE_HW_TIMEOUT (1<<17)
+/*
+ * 32-bit block count may not support eMMC where upper bits of CMD23 are used
+ * for other purposes. Consequently we support 16-bit block count by default.
+ * Otherwise, SDHCI_QUIRK2_USE_32BIT_BLK_CNT can be selected to use 32-bit
+ * block count.
+ */
+#define SDHCI_QUIRK2_USE_32BIT_BLK_CNT (1<<18)

int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */
--
2.7.4