[PATCH 1/3] clk: mux: Add regmap support for simple mux
Matthias Brugger
matthias.bgg at gmail.com
Fri May 29 08:24:58 PDT 2015
2015-05-29 8:40 GMT+02:00 Sascha Hauer <s.hauer at pengutronix.de>:
> On Thu, May 28, 2015 at 08:41:46PM +0200, Matthias Brugger wrote:
>> Some devices like SoCs from Mediatek need to use the clock muxes
>> through a regmap interface.
>> This patch adds regmap support for simple the simple multiplexer
>> clock code.
>>
>> Signed-off-by: Matthias Brugger <matthias.bgg at gmail.com>
>> ---
>> drivers/clk/clk-mux.c | 103 ++++++++++++++++++++++++++++++++++++++-----
>> include/linux/clk-provider.h | 40 +++++++++++++++++
>> 2 files changed, 132 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
>> index 1fa2a8d..c7c692a 100644
>> --- a/drivers/clk/clk-mux.c
>> +++ b/drivers/clk/clk-mux.c
>> @@ -29,6 +29,26 @@
>>
>> #define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)
>>
>> +static void clk_mux_writel(struct clk_mux *mux, u32 val)
>> +{
>> + if (mux->flags && CLK_MUX_USE_REGMAP)
>> + regmap_write(mux->regmap, mux->offset, val);
>> + else
>> + clk_writel(val, mux->reg);
>> +}
>> +
>> +static u32 clk_mux_readl(struct clk_mux *mux)
>> +{
>> + u32 val;
>> +
>> + if (mux->flags && CLK_MUX_USE_REGMAP)
>> + regmap_read(mux->regmap, mux->offset, &val);
>> + else
>> + val = clk_readl(mux->reg);
>> +
>> + return val;
>> +}
>> +
>> static u8 clk_mux_get_parent(struct clk_hw *hw)
>> {
>> struct clk_mux *mux = to_clk_mux(hw);
>> @@ -42,7 +62,10 @@ static u8 clk_mux_get_parent(struct clk_hw *hw)
>> * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
>> * val = 0x4 really means "bit 2, index starts at bit 0"
>> */
>> - val = clk_readl(mux->reg) >> mux->shift;
>> +
>> + val = clk_mux_readl(mux);
>> +
>> + val >>= mux->shift;
>> val &= mux->mask;
>>
>> if (mux->table) {
>> @@ -89,11 +112,11 @@ static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
>> if (mux->flags & CLK_MUX_HIWORD_MASK) {
>> val = mux->mask << (mux->shift + 16);
>> } else {
>> - val = clk_readl(mux->reg);
>> + val = clk_mux_readl(mux);
>> val &= ~(mux->mask << mux->shift);
>> }
>> val |= index << mux->shift;
>> - clk_writel(val, mux->reg);
>> + clk_mux_writel(mux, val);
>
> With regmap the register lock is inside the regmap, you must hold it
> during read/modify/write operations which means you have to use
> regmap_update_bits rather than regmap_read followed by regmap_write.
Fixed in next version.
Thanks for reviewing.
--
motzblog.wordpress.com
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