sunxi: mmc: Properly setup mod-clk and clock sampling phases

The sunxi mmc controller has both an internal clock divider, as well as
the divider in the mod0-clk for the mmc controller.

The internal divider cannot be used, as it conflicts with the setting of
clock sampling phases which is done in the mod0-clk, so it must be set to
0 (divide by 1).

For some reason while the kernel has had this correct from day one, the
u-boot sunxi mmc code has been using a fixed mod0-clk and setting its
internal divider depending on the desired speed. This is something which
we've inherited from the original Allwinner u-boot sources, but while this
has been fixed in Allwinner's own u-boot code at least for the A23 and later
upstream u-boot was still doing this wrong.

This commit fixes this, thereby also fixing mmc support not working reliable
on the A23 (which seems more sensitive to this) and possible also fixes some
other sunxi mmc issues.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/arm/include/asm/arch-sunxi/clock_sun6i.h b/arch/arm/include/asm/arch-sunxi/clock_sun6i.h
index 4bdc0de795..3d4fcd143f 100644
--- a/arch/arm/include/asm/arch-sunxi/clock_sun6i.h
+++ b/arch/arm/include/asm/arch-sunxi/clock_sun6i.h
@@ -219,10 +219,13 @@ struct sunxi_ccm_reg {
 #define AHB_GATE_OFFSET_LCD1		5
 #define AHB_GATE_OFFSET_LCD0		4
 
-#define CCM_MMC_CTRL_OSCM24 (0x0 << 24)
-#define CCM_MMC_CTRL_PLL6   (0x1 << 24)
-
-#define CCM_MMC_CTRL_ENABLE (0x1 << 31)
+#define CCM_MMC_CTRL_M(x)		((x) - 1)
+#define CCM_MMC_CTRL_OCLK_DLY(x)	((x) << 8)
+#define CCM_MMC_CTRL_N(x)		((x) << 16)
+#define CCM_MMC_CTRL_SCLK_DLY(x)	((x) << 20)
+#define CCM_MMC_CTRL_OSCM24		(0x0 << 24)
+#define CCM_MMC_CTRL_PLL6		(0x1 << 24)
+#define CCM_MMC_CTRL_ENABLE		(0x1 << 31)
 
 #define CCM_USB_CTRL_PHY1_RST (0x1 << 1)
 #define CCM_USB_CTRL_PHY2_RST (0x1 << 2)