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>

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;
 

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 */