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>

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index 2acfa41..6fa6868 100644 (file)
--- 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;
 

diff --git a/include/linux/mmc/sh_mmcif.h b/include/linux/mmc/sh_mmcif.h
index c4880ff..197ed91 100644 (file)
--- a/include/linux/mmc/sh_mmcif.h
+++ b/include/linux/mmc/sh_mmcif.h
@@ -36,6 +36,7 @@ struct sh_mmcif_plat_data {
        unsigned int            slave_id_tx;    /* embedded slave_id_[tr]x */
        unsigned int            slave_id_rx;
        bool                    use_cd_gpio : 1;
+       bool                    ccs_unsupported : 1;
        unsigned int            cd_gpio;
        u8                      sup_pclk;       /* 1 :SH7757, 0: SH7724/SH7372 */
        unsigned long           caps;