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path: root/drivers/clk/rockchip
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-rw-r--r--drivers/clk/rockchip/clk-mmc-phase.c23
-rw-r--r--drivers/clk/rockchip/clk-rk3228.c2
2 files changed, 24 insertions, 1 deletions
diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c
index 077fcdc7908b..fe7d9ed1d436 100644
--- a/drivers/clk/rockchip/clk-mmc-phase.c
+++ b/drivers/clk/rockchip/clk-mmc-phase.c
@@ -58,6 +58,12 @@ static int rockchip_mmc_get_phase(struct clk_hw *hw)
u16 degrees;
u32 delay_num = 0;
+ /* See the comment for rockchip_mmc_set_phase below */
+ if (!rate) {
+ pr_err("%s: invalid clk rate\n", __func__);
+ return -EINVAL;
+ }
+
raw_value = readl(mmc_clock->reg) >> (mmc_clock->shift);
degrees = (raw_value & ROCKCHIP_MMC_DEGREE_MASK) * 90;
@@ -84,6 +90,23 @@ static int rockchip_mmc_set_phase(struct clk_hw *hw, int degrees)
u32 raw_value;
u32 delay;
+ /*
+ * The below calculation is based on the output clock from
+ * MMC host to the card, which expects the phase clock inherits
+ * the clock rate from its parent, namely the output clock
+ * provider of MMC host. However, things may go wrong if
+ * (1) It is orphan.
+ * (2) It is assigned to the wrong parent.
+ *
+ * This check help debug the case (1), which seems to be the
+ * most likely problem we often face and which makes it difficult
+ * for people to debug unstable mmc tuning results.
+ */
+ if (!rate) {
+ pr_err("%s: invalid clk rate\n", __func__);
+ return -EINVAL;
+ }
+
nineties = degrees / 90;
remainder = (degrees % 90);
diff --git a/drivers/clk/rockchip/clk-rk3228.c b/drivers/clk/rockchip/clk-rk3228.c
index db6e5a9e6de6..53f16efbb8f4 100644
--- a/drivers/clk/rockchip/clk-rk3228.c
+++ b/drivers/clk/rockchip/clk-rk3228.c
@@ -369,7 +369,7 @@ static struct rockchip_clk_branch rk3228_clk_branches[] __initdata = {
RK2928_CLKSEL_CON(23), 5, 2, MFLAGS, 0, 6, DFLAGS,
RK2928_CLKGATE_CON(2), 15, GFLAGS),
- COMPOSITE(SCLK_SDMMC, "sclk_sdmmc0", mux_mmc_src_p, 0,
+ COMPOSITE(SCLK_SDMMC, "sclk_sdmmc", mux_mmc_src_p, 0,
RK2928_CLKSEL_CON(11), 8, 2, MFLAGS, 0, 8, DFLAGS,
RK2928_CLKGATE_CON(2), 11, GFLAGS),