For dividers with zero indicating clock is disabled, instead of giving a warning each time like "clkx: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set" in exist code, we'd consider it as a normal case and just return 0 in divider_recalc_rate function. For such clocks users should be aware of setting a correct rate before using.
e.g. 000b - Clock disabled 001b - Divide by 1 010b - Divide by 2 ... Cc: Stephen Boyd <[email protected]> Cc: Michael Turquette <[email protected]> Cc: Shawn Guo <[email protected]> Signed-off-by: Dong Aisheng <[email protected]> --- drivers/clk/clk-divider.c | 2 ++ include/linux/clk-provider.h | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 96386ff..f78ba7a 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -125,6 +125,8 @@ unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate, div = _get_div(table, val, flags, divider->width); if (!div) { + if (flags & CLK_DIVIDER_ZERO_GATE) + return 0; WARN(!(flags & CLK_DIVIDER_ALLOW_ZERO), "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n", clk_hw_get_name(hw)); diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index a428aec..a6efbb9 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -385,6 +385,9 @@ struct clk_div_table { * CLK_DIVIDER_MAX_AT_ZERO - For dividers which are like CLK_DIVIDER_ONE_BASED * except when the value read from the register is zero, the divisor is * 2^width of the field. + * CLK_DIVIDER_ZERO_GATE - For dividers which are like CLK_DIVIDER_ONE_BASED + * when the value read from the register is zero, it means the divisor + * output is disabled and the rate calculated will be 0. */ struct clk_divider { struct clk_hw hw; @@ -405,6 +408,7 @@ struct clk_divider { #define CLK_DIVIDER_ROUND_CLOSEST BIT(4) #define CLK_DIVIDER_READ_ONLY BIT(5) #define CLK_DIVIDER_MAX_AT_ZERO BIT(6) +#define CLK_DIVIDER_ZERO_GATE BIT(7) extern const struct clk_ops clk_divider_ops; extern const struct clk_ops clk_divider_ro_ops; -- 2.7.4
