mmc: tmio: move tmio_mmc_set_clock() to platform hook

tmio_mmc_set_clock() is full of quirks because different SoC vendors
extended this in different ways.

The original IP defines the divisor range 1/2 ... 1/512.

 bit 7 is set:    1/512
 bit 6 is set:    1/256
   ...
 bit 0 is set:    1/4
 all bits clear:  1/2

It is platform-dependent how to achieve the 1/1 clock.

I guess the TMIO-MFD variant uses the clock selector outside of this IP,
as far as I see tmio_core_mmc_clk_div() in drivers/mfd/tmio_core.c

I guess bit[7:0]=0xff is Renesas-specific extension.

Socionext (and Panasonic) uses bit 10 (CLKSEL) for 1/1.  Also, newer
versions of UniPhier SoC variants use bit 16 for 1/1024.

host->clk_update() is only used by the Renesas variants, whereas
host->set_clk_div() is only used by the TMIO-MFD variants.

To cope with this mess, promote tmio_mmc_set_clock() to a new
platform hook ->set_clock(), and melt the old two hooks into it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 61 insertions, 1 deletions

diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 68ece2f183cf..c2c0e444cfc9 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -152,6 +152,66 @@ static unsigned int renesas_sdhi_clk_update(struct tmio_mmc_host *host,
 	return ret == 0 ? best_freq : clk_get_rate(priv->clk);
 }
 
+static void renesas_sdhi_clk_start(struct tmio_mmc_host *host)
+{
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, CLK_CTL_SCLKEN |
+		sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
+
+	/* HW engineers overrode docs: no sleep needed on R-Car2+ */
+	if (!(host->pdata->flags & TMIO_MMC_MIN_RCAR2))
+		usleep_range(10000, 11000);
+}
+
+static void renesas_sdhi_clk_stop(struct tmio_mmc_host *host)
+{
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN &
+		sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
+
+	/* HW engineers overrode docs: no sleep needed on R-Car2+ */
+	if (!(host->pdata->flags & TMIO_MMC_MIN_RCAR2))
+		usleep_range(10000, 11000);
+}
+
+static void renesas_sdhi_set_clock(struct tmio_mmc_host *host,
+				   unsigned int new_clock)
+{
+	u32 clk = 0, clock;
+
+	if (new_clock == 0) {
+		renesas_sdhi_clk_stop(host);
+		return;
+	}
+	/*
+	 * Both HS400 and HS200/SD104 set 200MHz, but some devices need to
+	 * set 400MHz to distinguish the CPG settings in HS400.
+	 */
+	if (host->mmc->ios.timing == MMC_TIMING_MMC_HS400 &&
+	    host->pdata->flags & TMIO_MMC_HAVE_4TAP_HS400 &&
+	    new_clock == 200000000)
+		new_clock = 400000000;
+
+	clock = renesas_sdhi_clk_update(host, new_clock) / 512;
+
+	for (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)) {
+		if (!(host->mmc->ios.timing == MMC_TIMING_MMC_HS400))
+			clk |= 0xff;
+		else
+			clk &= ~0xff;
+	}
+
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN &
+			sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, clk & CLK_CTL_DIV_MASK);
+	if (!(host->pdata->flags & TMIO_MMC_MIN_RCAR2))
+		usleep_range(10000, 11000);
+
+	renesas_sdhi_clk_start(host);
+}
+
 static void renesas_sdhi_clk_disable(struct tmio_mmc_host *host)
 {
 	struct renesas_sdhi *priv = host_to_priv(host);
@@ -617,8 +677,8 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 
 	host->write16_hook	= renesas_sdhi_write16_hook;
 	host->clk_enable	= renesas_sdhi_clk_enable;
-	host->clk_update	= renesas_sdhi_clk_update;
 	host->clk_disable	= renesas_sdhi_clk_disable;
+	host->set_clock		= renesas_sdhi_set_clock;
 	host->multi_io_quirk	= renesas_sdhi_multi_io_quirk;
 	host->dma_ops		= dma_ops;