mmc: tmio: add actual clock support as option

Some controller is supporting actual clock on SD_CLK_CTRL :: DIV[7:0].
Renesas SH-Mobile SDHI doesn't support,
but, Renesas R-Car SDHI supports it.
This patch adds new TMIO_MMC_CLK_ACTUAL flag for it.

[Kuninori Morimoto: tidyuped for upstreaming]

Tested-by: Nguyen Xuan Nui <nx-nui@jinso.co.jp>
Tested-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Shinobu Uehara <shinobu.uehara.xc@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: Shinobu Uehara

drivers/mmc/host/sh_mobile_sdhi.c

@@ -49,12 +49,14 @@ static const struct sh_mobile_sdhi_of_data sh_mobile_sdhi_of_cfg[] = {
 };
 
 static const struct sh_mobile_sdhi_of_data of_rcar_gen1_compatible = {
-	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE,
+	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
+			  TMIO_MMC_CLK_ACTUAL,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
 };
 
 static const struct sh_mobile_sdhi_of_data of_rcar_gen2_compatible = {
-	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE,
+	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
+			  TMIO_MMC_CLK_ACTUAL,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
 	.capabilities2	= MMC_CAP2_NO_MULTI_READ,
 	.dma_rx_offset	= 0x2000,

drivers/mmc/host/tmio_mmc_pio.c

@@ -159,6 +159,11 @@ static void tmio_mmc_set_clock(struct tmio_mmc_host *host,
 		for (clock = host->mmc->f_min, clk = 0x80000080;
 			new_clock >= (clock<<1); clk >>= 1)
 			clock <<= 1;
+
+		/* 1/1 clock is option */
+		if ((host->pdata->flags & TMIO_MMC_CLK_ACTUAL) &&
+		    ((clk >> 22) & 0x1))
+			clk |= 0xff;
 	}
 
 	if (host->set_clk_div)

include/linux/mfd/tmio.h

@@ -99,6 +99,11 @@
  */
 #define TMIO_MMC_HAVE_CTL_DMA_REG	(1 << 9)
 
+/*
+ * Some controllers allows to set SDx actual clock
+ */
+#define TMIO_MMC_CLK_ACTUAL		(1 << 10)
+
 int tmio_core_mmc_enable(void __iomem *cnf, int shift, unsigned long base);
 int tmio_core_mmc_resume(void __iomem *cnf, int shift, unsigned long base);
 void tmio_core_mmc_pwr(void __iomem *cnf, int shift, int state);