clk: renesas: rcar-gen3: Set state when registering SD clocks
authorNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Thu, 29 Nov 2018 00:15:38 +0000 (01:15 +0100)
committerGeert Uytterhoeven <geert+renesas@glider.be>
Fri, 7 Dec 2018 10:45:00 +0000 (11:45 +0100)
The driver tries to figure out which state a SD clock is in when the
clock is registered, instead of setting a known state. This can be
problematic for two reasons.

1. If the clock driver can't figure out the state of the clock,
   registration of the clock fails, and setting of a known state by a
   clock user is not possible.

2. The state of the clock depends on if and how the bootloader
   configured it. The driver only checks that the rate is known, not if
   the clock is stopped or not for example.

Fix this by setting a known state and making sure the clock is stopped.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
drivers/clk/renesas/rcar-gen3-cpg.c

index 4ba38f98cc7bab8296631c04e1d3901870e4891e..6033bacd25f6f7b9b5fa50ae63a6898da0d11a9b 100644 (file)
@@ -360,7 +360,7 @@ static struct clk * __init cpg_sd_clk_register(const struct cpg_core_clk *core,
        struct sd_clock *clock;
        struct clk *clk;
        unsigned int i;
-       u32 sd_fc;
+       u32 val;
 
        clock = kzalloc(sizeof(*clock), GFP_KERNEL);
        if (!clock)
@@ -377,17 +377,9 @@ static struct clk * __init cpg_sd_clk_register(const struct cpg_core_clk *core,
        clock->div_table = cpg_sd_div_table;
        clock->div_num = ARRAY_SIZE(cpg_sd_div_table);
 
-       sd_fc = readl(clock->csn.reg) & CPG_SD_FC_MASK;
-       for (i = 0; i < clock->div_num; i++)
-               if (sd_fc == (clock->div_table[i].val & CPG_SD_FC_MASK))
-                       break;
-
-       if (WARN_ON(i >= clock->div_num)) {
-               kfree(clock);
-               return ERR_PTR(-EINVAL);
-       }
-
-       clock->cur_div_idx = i;
+       val = readl(clock->csn.reg) & ~CPG_SD_FC_MASK;
+       val |= CPG_SD_STP_MASK | (clock->div_table[0].val & CPG_SD_FC_MASK);
+       writel(val, clock->csn.reg);
 
        clock->div_max = clock->div_table[0].div;
        clock->div_min = clock->div_max;