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Subject[PATCH V3 3/7] mmc: sdhci: add ADMA2 64-bit addressing support for V4 mode
Date
ADMA2 64-bit addressing support is divided into V3 mode and V4 mode.
So there are two kinds of descriptors for ADMA2 64-bit addressing
i.e. 96-bit Descriptor for V3 mode, and 128-bit Descriptor for V4
mode. 128-bit Descriptor is aligned to 8-byte.

For V4 mode, ADMA2 64-bit addressing is enabled via Host Control 2
register.

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
---
drivers/mmc/host/sdhci.c | 28 ++++++++++++++++++++++++----
drivers/mmc/host/sdhci.h | 14 ++++++++++++--
2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c7de6a5..7871ae2 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3486,6 +3486,26 @@ static int sdhci_allocate_bounce_buffer(struct sdhci_host *host)
return 0;
}

+static inline bool sdhci_use_64bit_dma(struct sdhci_host *host)
+{
+ u32 addr64bit_en;
+
+ /*
+ * According to SD Host Controller spec v4.10, bit[27] added from
+ * version 4.10 in Capabilities Register is used as 64-bit System
+ * Address support for V4 mode, 64-bit DMA Addressing for V4 mode
+ * is enabled only if 64-bit Addressing =1 in the Host Control 2
+ * register.
+ */
+ if (host->version == SDHCI_SPEC_410 && host->v4_mode) {
+ addr64bit_en = (sdhci_readw(host, SDHCI_HOST_CONTROL2) &
+ SDHCI_CTRL_64BIT_ADDR);
+ return addr64bit_en && (host->caps & SDHCI_CAN_64BIT_V4);
+ }
+
+ return host->caps & SDHCI_CAN_64BIT;
+}
+
int sdhci_setup_host(struct sdhci_host *host)
{
struct mmc_host *mmc;
@@ -3557,7 +3577,7 @@ int sdhci_setup_host(struct sdhci_host *host)
* SDHCI_QUIRK2_BROKEN_64_BIT_DMA must be left to the drivers to
* implement.
*/
- if (host->caps & SDHCI_CAN_64BIT)
+ if (sdhci_use_64bit_dma(host))
host->flags |= SDHCI_USE_64_BIT_DMA;

if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
@@ -3591,8 +3611,8 @@ int sdhci_setup_host(struct sdhci_host *host)
*/
if (host->flags & SDHCI_USE_64_BIT_DMA) {
host->adma_table_sz = (SDHCI_MAX_SEGS * 2 + 1) *
- SDHCI_ADMA2_64_DESC_SZ;
- host->desc_sz = SDHCI_ADMA2_64_DESC_SZ;
+ SDHCI_ADMA2_64_DESC_SZ(host);
+ host->desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
} else {
host->adma_table_sz = (SDHCI_MAX_SEGS * 2 + 1) *
SDHCI_ADMA2_32_DESC_SZ;
@@ -3600,7 +3620,7 @@ int sdhci_setup_host(struct sdhci_host *host)
}

host->align_buffer_sz = SDHCI_MAX_SEGS * SDHCI_ADMA2_ALIGN;
- buf = dma_alloc_coherent(mmc_dev(mmc), host->align_buffer_sz +
+ buf = dma_zalloc_coherent(mmc_dev(mmc), host->align_buffer_sz +
host->adma_table_sz, &dma, GFP_KERNEL);
if (!buf) {
pr_warn("%s: Unable to allocate ADMA buffers - falling back to standard DMA\n",
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index e98249b..24fa58a 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -185,6 +185,7 @@
#define SDHCI_CTRL_EXEC_TUNING 0x0040
#define SDHCI_CTRL_TUNED_CLK 0x0080
#define SDHCI_CTRL_V4_MODE 0x1000
+#define SDHCI_CTRL_64BIT_ADDR 0x2000
#define SDHCI_CTRL_PRESET_VAL_ENABLE 0x8000

#define SDHCI_CAPABILITIES 0x40
@@ -205,6 +206,7 @@
#define SDHCI_CAN_VDD_330 0x01000000
#define SDHCI_CAN_VDD_300 0x02000000
#define SDHCI_CAN_VDD_180 0x04000000
+#define SDHCI_CAN_64BIT_V4 0x08000000
#define SDHCI_CAN_64BIT 0x10000000

#define SDHCI_SUPPORT_SDR50 0x00000001
@@ -271,6 +273,8 @@
#define SDHCI_SPEC_100 0
#define SDHCI_SPEC_200 1
#define SDHCI_SPEC_300 2
+#define SDHCI_SPEC_400 3
+#define SDHCI_SPEC_410 4

/*
* End of controller registers.
@@ -306,8 +310,14 @@ struct sdhci_adma2_32_desc {
*/
#define SDHCI_ADMA2_DESC_ALIGN 8

-/* ADMA2 64-bit DMA descriptor size */
-#define SDHCI_ADMA2_64_DESC_SZ 12
+/*
+ * ADMA2 64-bit DMA descriptor size
+ * According to SD Host Controller spec v4.10, there are two kinds of
+ * descriptors for 64-bit addressing mode: 96-bit Descriptor and 128-bit
+ * Descriptor, if Host Version 4 Enable is set in the Host Control 2
+ * register, 128-bit Descriptor will be selected.
+ */
+#define SDHCI_ADMA2_64_DESC_SZ(host) ((host)->v4_mode ? 16 : 12)

/*
* ADMA2 64-bit descriptor. Note 12-byte descriptor can't always be 8-byte
--
2.7.4
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