Re: [PATCH 4/9] clk: sunxi-ng: mux: Add support for mux tables

[Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>]

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On Tue, Jul 26, 2016 at 03:04:26PM +0800, Chen-Yu Tsai wrote:
> Some clock muxes have holes, i.e. invalid or unconnected inputs,
> between parent mux values.
> 
> Add support for specifying a mux table to map clock parents to
> mux values.
> 
> Signed-off-by: Chen-Yu Tsai <wens-jdAy2FN1RRM@public.gmane.org>
> ---
>  drivers/clk/sunxi-ng/ccu_mux.c | 12 ++++++++++++
>  drivers/clk/sunxi-ng/ccu_mux.h | 12 ++++++++++--
>  2 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
> index 1329b9ab481e..68b32f168a74 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.c
> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
> @@ -107,6 +107,15 @@ u8 ccu_mux_helper_get_parent(struct ccu_common *common,
>  	parent = reg >> cm->shift;
>  	parent &= (1 << cm->width) - 1;
>  
> +	if (cm->table) {
> +		int num_parents = clk_hw_get_num_parents(&common->hw);
> +		int i;
> +
> +		for (i = 0; i < num_parents; i++)
> +			if (cm->table[i] == parent)
> +				return i;
> +	}
> +
>  	return parent;
>  }
>  
> @@ -117,6 +126,9 @@ int ccu_mux_helper_set_parent(struct ccu_common *common,
>  	unsigned long flags;
>  	u32 reg;
>  
> +	if (cm->table)
> +		index = cm->table[index];
> +
>  	spin_lock_irqsave(common->lock, flags);
>  
>  	reg = readl(common->base + common->reg);
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.h b/drivers/clk/sunxi-ng/ccu_mux.h
> index d35ce5e93840..f0078de78712 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.h
> +++ b/drivers/clk/sunxi-ng/ccu_mux.h
> @@ -6,8 +6,9 @@
>  #include "ccu_common.h"
>  
>  struct ccu_mux_internal {
> -	u8	shift;
> -	u8	width;
> +	u8		shift;
> +	u8		width;
> +	const u8	*table;
>  
>  	struct {
>  		u8	index;
> @@ -21,6 +22,13 @@ struct ccu_mux_internal {
>  	} variable_prediv;
>  };
>  
> +#define SUNXI_CLK_MUX_TABLE(_shift, _width, _table)	\
> +	{						\
> +		.shift	= _shift,			\
> +		.width	= _width,			\
> +		.table	= _table,			\
> +	}
> +

I basically had the exact same patch done a few days ago :)

This is in my A64 serie, together with some cleanup on that macro that
is not consistent with the other internal structures.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com