mmc: sh_mmcif: revision-specific CLK_CTRL2 handling

Some newer MMCIF IP revisions contain a CE_CLK_CTRL2 register, that has to
be set for proper operation. Support 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>

2 files changed, 6 insertions, 0 deletions

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index 6fa6868d1030..36629a024aa1 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -247,6 +247,7 @@ struct sh_mmcif_host {
         bool power;
         bool card_present;
         bool ccs_enable;                /* Command Completion Signal support */
+        bool clk_ctrl2_enable;
         struct mutex thread_lock;
 
         /* DMA support */
@@ -497,6 +498,8 @@ static void sh_mmcif_sync_reset(struct sh_mmcif_host *host)
         sh_mmcif_writel(host->addr, MMCIF_CE_VERSION, SOFT_RST_OFF);
         if (host->ccs_enable)
                 tmp |= SCCSTO_29;
+        if (host->clk_ctrl2_enable)
+                sh_mmcif_writel(host->addr, MMCIF_CE_CLK_CTRL2, 0x0F0F0000);
         sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, tmp |
                 SRSPTO_256 | SRBSYTO_29 | SRWDTO_29);
         /* byte swap on */
@@ -1398,6 +1401,7 @@ static int sh_mmcif_probe(struct platform_device *pdev)
         host->addr      = reg;
         host->timeout   = msecs_to_jiffies(1000);
         host->ccs_enable = !pd || !pd->ccs_unsupported;
+        host->clk_ctrl2_enable = pd && pd->clk_ctrl2_present;
 
         host->pd = pdev;
 
diff --git a/include/linux/mmc/sh_mmcif.h b/include/linux/mmc/sh_mmcif.h
index 197ed91f6a0c..ccd8fb2cad52 100644
--- a/include/linux/mmc/sh_mmcif.h
+++ b/include/linux/mmc/sh_mmcif.h
@@ -37,6 +37,7 @@ struct sh_mmcif_plat_data {
         unsigned int            slave_id_rx;
         bool                    use_cd_gpio : 1;
         bool                    ccs_unsupported : 1;
+        bool                    clk_ctrl2_present : 1;
         unsigned int            cd_gpio;
         u8                      sup_pclk;       /* 1 :SH7757, 0: SH7724/SH7372 */
         unsigned long           caps;
@@ -60,6 +61,7 @@ struct sh_mmcif_plat_data {
 #define MMCIF_CE_INT_MASK       0x00000044
 #define MMCIF_CE_HOST_STS1      0x00000048
 #define MMCIF_CE_HOST_STS2      0x0000004C
+#define MMCIF_CE_CLK_CTRL2      0x00000070
 #define MMCIF_CE_VERSION        0x0000007C
 
 /* CE_BUF_ACC */