sunxi: mmc: Fix phase delays

U-boot driver for sunxi-mmc uses PLL6, unlike linux kernel where
PLL5 is used, with clock rates respectively 600MHz and 768MHz.
Thus there are different phase degree steps - 24 for the kernel and
30 for u-boot.

In the kernel driver the phase is set 90 deg for output and 120 for
sample. Dividing by 30 will result values 3 and 4. Those are the
values set in the u-boot driver.

However, the condition defining delays is wrong. MMC core driver
requests clock of 52MHz, sunxi-driver sets clock of 50MHz, but
phase is set 30 deg for output and 120 deg for sample.

Apparently this works for most cards.
On A20-SOM204-EVB-eMMC there is eMMC card (KLMAG2GEND) which complains
about it. Maybe there is other boards with similar problem?
So the fix is to match delays for both u-boot and kernel.

Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>

diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
index df6f32850e28e2c210caba5088e816176b12cd56..f4c245c5ebaeff1b977f6b3e75dd33e694505d2f 100644 (file)
--- a/drivers/mmc/sunxi_mmc.c
+++ b/drivers/mmc/sunxi_mmc.c
@@ -147,19 +147,19 @@ static int mmc_set_mod_clk(struct sunxi_mmc_priv *priv, unsigned int hz)
                oclk_dly = 0;
                sclk_dly = 5;
 #ifdef CONFIG_MACH_SUN9I
-       } else if (hz <= 50000000) {
+       } else if (hz <= 52000000) {
                oclk_dly = 5;
                sclk_dly = 4;
        } else {
-               /* hz > 50000000 */
+               /* hz > 52000000 */
                oclk_dly = 2;
                sclk_dly = 4;
 #else
-       } else if (hz <= 50000000) {
+       } else if (hz <= 52000000) {
                oclk_dly = 3;
                sclk_dly = 4;
        } else {
-               /* hz > 50000000 */
+               /* hz > 52000000 */
                oclk_dly = 1;
                sclk_dly = 4;
 #endif