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clk: sprd: check its parent status before reading gate clock

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Some clocks only can be accessed if their parent is enabled. mipi_csi_xx
clocks on SC9863A are an examples. We have to ensure the parent clock is
enabled when reading those clocks.

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lkml.kernel.org/r/20200527053638.31439-2-zhang.lyra@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Chunyan Zhang 2020-05-27 13:36:35 +08:00 committed by Stephen Boyd
parent c2f30986d4
commit 8b4f6b8d59
2 changed files with 16 additions and 0 deletions
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7
drivers/clk/sprd/gate.c
View File

@ -94,8 +94,15 @@ static int sprd_gate_is_enabled(struct clk_hw *hw)
{
struct sprd_gate *sg = hw_to_sprd_gate(hw);
struct sprd_clk_common *common = &sg->common;
struct clk_hw *parent;
unsigned int reg;
if (sg->flags & SPRD_GATE_NON_AON) {
parent = clk_hw_get_parent(hw);
if (!parent || !clk_hw_is_enabled(parent))
return 0;
}
regmap_read(common->regmap, common->reg, &reg);
if (sg->flags & CLK_GATE_SET_TO_DISABLE)

9
drivers/clk/sprd/gate.h
View File

@ -19,6 +19,15 @@ struct sprd_gate {
struct sprd_clk_common common;
};
/*
* sprd_gate->flags is used for:
* CLK_GATE_SET_TO_DISABLE BIT(0)
* CLK_GATE_HIWORD_MASK BIT(1)
* CLK_GATE_BIG_ENDIAN BIT(2)
* so we define new flags from BIT(3)
*/
#define SPRD_GATE_NON_AON BIT(3) /* not alway powered on, check before read */
#define SPRD_SC_GATE_CLK_HW_INIT_FN(_struct, _name, _parent, _reg, \
_sc_offset, _enable_mask, _flags, \
_gate_flags, _udelay, _ops, _fn) \