mmc: sh_mmcif: revision-specific Command Completion Signal handling

Some earlier MMCIF IP revisions contained Command Completion Signal
support, which has been dropped again in modern versions. Sopport for
this feature is added in a way to preserve the current behaviour by
default, i.e. when it is not enabled in platform data. Patch is based
on work by Nobuyuki HIRAI.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 21 insertions, 6 deletions

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index 2acfa41d609f..6fa6868d1030 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -134,6 +134,8 @@
                                  INT_BUFWEN | INT_CMD12DRE | INT_BUFRE | \
                                  INT_DTRANE | INT_CMD12RBE | INT_CMD12CRE)
 
+#define INT_CCS                 (INT_CCSTO | INT_CCSRCV | INT_CCSDE)
+
 /* CE_INT_MASK */
 #define MASK_ALL                0x00000000
 #define MASK_MCCSDE             (1 << 29)
@@ -162,7 +164,7 @@
 
 #define MASK_START_CMD          (MASK_MCMDVIO | MASK_MBUFVIO | MASK_MWDATERR | \
                                  MASK_MRDATERR | MASK_MRIDXERR | MASK_MRSPERR | \
-                                 MASK_MCCSTO | MASK_MCRCSTO | MASK_MWDATTO | \
+                                 MASK_MCRCSTO | MASK_MWDATTO | \
                                  MASK_MRDATTO | MASK_MRBSYTO | MASK_MRSPTO)
 
 #define MASK_CLEAN              (INT_ERR_STS | MASK_MRBSYE | MASK_MCRSPE |      \
@@ -244,6 +246,7 @@ struct sh_mmcif_host {
         int sg_blkidx;
         bool power;
         bool card_present;
+        bool ccs_enable;                /* Command Completion Signal support */
         struct mutex thread_lock;
 
         /* DMA support */
@@ -492,8 +495,10 @@ static void sh_mmcif_sync_reset(struct sh_mmcif_host *host)
 
         sh_mmcif_writel(host->addr, MMCIF_CE_VERSION, SOFT_RST_ON);
         sh_mmcif_writel(host->addr, MMCIF_CE_VERSION, SOFT_RST_OFF);
+        if (host->ccs_enable)
+                tmp |= SCCSTO_29;
         sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, tmp |
-                SRSPTO_256 | SRBSYTO_29 | SRWDTO_29 | SCCSTO_29);
+                SRSPTO_256 | SRBSYTO_29 | SRWDTO_29);
         /* byte swap on */
         sh_mmcif_bitset(host, MMCIF_CE_BUF_ACC, BUF_ACC_ATYP);
 }
@@ -873,6 +878,9 @@ static void sh_mmcif_start_cmd(struct sh_mmcif_host *host,
                 break;
         }
 
+        if (host->ccs_enable)
+                mask |= MASK_MCCSTO;
+
         if (mrq->data) {
                 sh_mmcif_writel(host->addr, MMCIF_CE_BLOCK_SET, 0);
                 sh_mmcif_writel(host->addr, MMCIF_CE_BLOCK_SET,
@@ -880,7 +888,10 @@ static void sh_mmcif_start_cmd(struct sh_mmcif_host *host,
         }
         opc = sh_mmcif_set_cmd(host, mrq);
 
-        sh_mmcif_writel(host->addr, MMCIF_CE_INT, 0xD80430C0);
+        if (host->ccs_enable)
+                sh_mmcif_writel(host->addr, MMCIF_CE_INT, 0xD80430C0);
+        else
+                sh_mmcif_writel(host->addr, MMCIF_CE_INT, 0xD80430C0 | INT_CCS);
         sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, mask);
         /* set arg */
         sh_mmcif_writel(host->addr, MMCIF_CE_ARG, cmd->arg);
@@ -1245,11 +1256,14 @@ static irqreturn_t sh_mmcif_irqt(int irq, void *dev_id)
 static irqreturn_t sh_mmcif_intr(int irq, void *dev_id)
 {
         struct sh_mmcif_host *host = dev_id;
-        u32 state;
+        u32 state, mask;
 
         state = sh_mmcif_readl(host->addr, MMCIF_CE_INT);
-        sh_mmcif_writel(host->addr, MMCIF_CE_INT,
-                        ~(state & sh_mmcif_readl(host->addr, MMCIF_CE_INT_MASK)));
+        mask = sh_mmcif_readl(host->addr, MMCIF_CE_INT_MASK);
+        if (host->ccs_enable)
+                sh_mmcif_writel(host->addr, MMCIF_CE_INT, ~(state & mask));
+        else
+                sh_mmcif_writel(host->addr, MMCIF_CE_INT, INT_CCS | ~(state & mask));
         sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, state & MASK_CLEAN);
 
         if (state & ~MASK_CLEAN)
@@ -1383,6 +1397,7 @@ static int sh_mmcif_probe(struct platform_device *pdev)
         host->mmc       = mmc;
         host->addr      = reg;
         host->timeout   = msecs_to_jiffies(1000);
+        host->ccs_enable = !pd || !pd->ccs_unsupported;
 
         host->pd = pdev;