[PATCH 6/8] mci: sdhci: Add 64-bit DMA addressing suport for V4 mode

[Jules Maselbas <jmaselbas@kalray.eu>]

Adapted from Linux commit:
8<----------------------------------------------------------------------
commit 685e444bbaa0a5ed959f39dbb2f219eb44c30421
Author: Chunyan Zhang <zhang.chunyan@linaro.org>
Date:   Thu Aug 30 16:21:40 2018 +0800

    mmc: sdhci: Add ADMA2 64-bit addressing support for V4 mode

    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>
    Acked-by: Adrian Hunter <adrian.hunter@intel.com>
    [Ulf: Fixed conflict while applying]
    Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
8<----------------------------------------------------------------------

Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
---
 drivers/mci/sdhci.c | 64 +++++++++++++++++++++++++++++++++++++++++++--
 drivers/mci/sdhci.h | 15 +++++++++++
 2 files changed, 77 insertions(+), 2 deletions(-)

diff --git a/drivers/mci/sdhci.c b/drivers/mci/sdhci.c
index bce4ff2a14..4aca3af5aa 100644
--- a/drivers/mci/sdhci.c
+++ b/drivers/mci/sdhci.c
@@ -111,6 +111,35 @@ void sdhci_set_bus_width(struct sdhci *host, int width)
 	sdhci_write8(host, SDHCI_HOST_CONTROL, ctrl);
 }
 
+static inline bool sdhci_can_64bit_dma(struct sdhci *host)
+{
+	/*
+	 * 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.
+	 */
+	if (host->version >= SDHCI_SPEC_410 && host->v4_mode)
+		return host->caps & SDHCI_CAN_64BIT_V4;
+
+	return host->caps & SDHCI_CAN_64BIT;
+}
+
+
+static void sdhci_set_adma_addr(struct sdhci *host, dma_addr_t addr)
+{
+	sdhci_write32(host, SDHCI_ADMA_ADDRESS, lower_32_bits(addr));
+	if (host->flags & SDHCI_USE_64_BIT_DMA)
+		sdhci_write32(host, SDHCI_ADMA_ADDRESS_HI, upper_32_bits(addr));
+}
+
+static void sdhci_set_sdma_addr(struct sdhci *host, dma_addr_t addr)
+{
+	if (host->v4_mode)
+		sdhci_set_adma_addr(host, addr);
+	else
+		sdhci_write32(host, SDHCI_DMA_ADDRESS, addr);
+}
+
 #ifdef __PBL__
 /*
  * Stubs to make timeout logic below work in PBL
@@ -160,6 +189,33 @@ void sdhci_setup_data_pio(struct sdhci *sdhci, struct mci_data *data)
 		      SDHCI_TRANSFER_BLOCK_SIZE(data->blocksize) | data->blocks << 16);
 }
 
+static void sdhci_config_dma(struct sdhci *host)
+{
+	u8 ctrl;
+	u16 ctrl2;
+
+	if (host->version < SDHCI_SPEC_200)
+		return;
+
+	ctrl = sdhci_read8(host, SDHCI_HOST_CONTROL);
+	/* Note if DMA Select is zero then SDMA is selected */
+	ctrl &= ~SDHCI_CTRL_DMA_MASK;
+	sdhci_write8(host, SDHCI_HOST_CONTROL, ctrl);
+
+	if (host->flags & SDHCI_USE_64_BIT_DMA) {
+		/*
+		 * If v4 mode, all supported DMA can be 64-bit addressing if
+		 * controller supports 64-bit system address, otherwise only
+		 * ADMA can support 64-bit addressing.
+		 */
+		if (host->v4_mode) {
+			ctrl2 = sdhci_read16(host, SDHCI_HOST_CONTROL2);
+			ctrl2 |= SDHCI_CTRL_64BIT_ADDR;
+			sdhci_write16(host, SDHCI_HOST_CONTROL2, ctrl2);
+		}
+	}
+}
+
 void sdhci_setup_data_dma(struct sdhci *sdhci, struct mci_data *data,
 			  dma_addr_t *dma)
 {
@@ -188,7 +244,8 @@ void sdhci_setup_data_dma(struct sdhci *sdhci, struct mci_data *data,
 		return;
 	}
 
-	sdhci_write32(sdhci, SDHCI_DMA_ADDRESS, *dma);
+	sdhci_config_dma(sdhci);
+	sdhci_set_sdma_addr(sdhci, *dma);
 }
 
 int sdhci_transfer_data_dma(struct sdhci *sdhci, struct mci_data *data,
@@ -230,7 +287,7 @@ int sdhci_transfer_data_dma(struct sdhci *sdhci, struct mci_data *data,
 			 * the interrupt and kick the DMA engine again.
 			 */
 			sdhci_write32(sdhci, SDHCI_INT_STATUS, SDHCI_INT_DMA);
-			sdhci_write32(sdhci, SDHCI_DMA_ADDRESS, addr);
+			sdhci_set_sdma_addr(sdhci, dma);
 		}
 
 		if (irqstat & SDHCI_INT_XFER_COMPLETE)
@@ -594,5 +651,8 @@ int sdhci_setup_host(struct sdhci *host)
 
 	host->sdma_boundary = SDHCI_DMA_BOUNDARY_512K;
 
+	if (sdhci_can_64bit_dma(host))
+		host->flags |= SDHCI_USE_64_BIT_DMA;
+
 	return 0;
 }
diff --git a/drivers/mci/sdhci.h b/drivers/mci/sdhci.h
index 1f5d0564fc..f3ffd62dff 100644
--- a/drivers/mci/sdhci.h
+++ b/drivers/mci/sdhci.h
@@ -197,6 +197,21 @@ struct sdhci {
 	int max_clk; /* Max possible freq (Hz) */
 	int clk_mul; /* Clock Muliplier value */
 
+	int flags;		/* Host attributes */
+#define SDHCI_USE_SDMA		(1<<0)	/* Host is SDMA capable */
+#define SDHCI_USE_ADMA		(1<<1)	/* Host is ADMA capable */
+#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_AUTO_CMD12	(1<<6)	/* Auto CMD12 support */
+#define SDHCI_AUTO_CMD23	(1<<7)	/* Auto CMD23 support */
+#define SDHCI_PV_ENABLED	(1<<8)	/* Preset value enabled */
+#define SDHCI_USE_64_BIT_DMA	(1<<12)	/* Use 64-bit DMA */
+#define SDHCI_HS400_TUNING	(1<<13)	/* Tuning for HS400 */
+#define SDHCI_SIGNALING_330	(1<<14)	/* Host is capable of 3.3V signaling */
+#define SDHCI_SIGNALING_180	(1<<15)	/* Host is capable of 1.8V signaling */
+#define SDHCI_SIGNALING_120	(1<<16)	/* Host is capable of 1.2V signaling */
+
 	unsigned int version; /* SDHCI spec. version */
 
 	enum mci_timing timing;
-- 
2.17.1