lkml.org 
[lkml]   [2017]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [linux-sunxi] [PATCH 1/2] clk: sunxi-ng: Support fixed post-dividers on MP style clocks
From
Date
Hi Chen-Yu,

On 04/12/17 05:19, Chen-Yu Tsai wrote:
> On the A64, the MMC module clocks are fixed in the new timing mode,
> i.e. they do not have a bit to select the mode. These clocks have
> a 2x divider somewhere between the clock and the MMC module.
>
> To be consistent with other SoCs supporting the new timing mode,
> we model the 2x divider as a fixed post-divider on the MMC module
> clocks.
>
> To do this, we first add fixed post-divider to the MP style clocks,
> which the MMC module clocks are.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
> drivers/clk/sunxi-ng/ccu_mp.c | 20 ++++++++++++++++++--
> drivers/clk/sunxi-ng/ccu_mp.h | 24 ++++++++++++++++++++++++
> 2 files changed, 42 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
> index 688855e7dc8c..5d0af4051737 100644
> --- a/drivers/clk/sunxi-ng/ccu_mp.c
> +++ b/drivers/clk/sunxi-ng/ccu_mp.c
> @@ -50,12 +50,19 @@ static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux,
> unsigned int max_m, max_p;
> unsigned int m, p;
>
> + if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
> + rate *= cmp->fixed_post_div;

Can't you just initialise fixed_post_div to 1 normally and save the
CCU_FEATURE_FIXED_POSTDIV?

> +
> max_m = cmp->m.max ?: 1 << cmp->m.width;
> max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
>
> ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p);
> + rate = *parent_rate / p / m;
> +
> + if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
> + rate /= cmp->fixed_post_div;
>
> - return *parent_rate / p / m;
> + return rate;
> }
>
> static void ccu_mp_disable(struct clk_hw *hw)
> @@ -83,6 +90,7 @@ static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
> unsigned long parent_rate)
> {
> struct ccu_mp *cmp = hw_to_ccu_mp(hw);
> + unsigned long rate;
> unsigned int m, p;
> u32 reg;
>
> @@ -101,7 +109,11 @@ static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
> p = reg >> cmp->p.shift;
> p &= (1 << cmp->p.width) - 1;
>
> - return (parent_rate >> p) / m;
> + rate = (parent_rate >> p) / m;
> + if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
> + rate /= cmp->fixed_post_div;
> +
> + return rate;
> }
>
> static int ccu_mp_determine_rate(struct clk_hw *hw,
> @@ -129,6 +141,10 @@ static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate,
> max_m = cmp->m.max ?: 1 << cmp->m.width;
> max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
>
> + /* Adjust target rate according to post-dividers */
> + if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
> + rate = rate * cmp->fixed_post_div;
> +
> ccu_mp_find_best(parent_rate, rate, max_m, max_p, &m, &p);
>
> spin_lock_irqsave(cmp->common.lock, flags);
> diff --git a/drivers/clk/sunxi-ng/ccu_mp.h b/drivers/clk/sunxi-ng/ccu_mp.h
> index aaef11d747ea..5107635e61de 100644
> --- a/drivers/clk/sunxi-ng/ccu_mp.h
> +++ b/drivers/clk/sunxi-ng/ccu_mp.h
> @@ -33,9 +33,33 @@ struct ccu_mp {
> struct ccu_div_internal m;
> struct ccu_div_internal p;
> struct ccu_mux_internal mux;
> +
> + unsigned int fixed_post_div;
> +
> struct ccu_common common;
> };
>
> +#define SUNXI_CCU_MP_WITH_MUX_GATE_POSTDIV(_struct, _name, _parents, _reg, \
> + _mshift, _mwidth, \
> + _pshift, _pwidth, \
> + _muxshift, _muxwidth, \
> + _gate, _postdiv, _flags) \
> + struct ccu_mp _struct = { \
> + .enable = _gate, \
> + .m = _SUNXI_CCU_DIV(_mshift, _mwidth), \
> + .p = _SUNXI_CCU_DIV(_pshift, _pwidth), \
> + .mux = _SUNXI_CCU_MUX(_muxshift, _muxwidth), \
> + .fixed_post_div = _postdiv, \
> + .common = { \
> + .reg = _reg, \
> + .features = CCU_FEATURE_FIXED_POSTDIV, \
> + .hw.init = CLK_HW_INIT_PARENTS(_name, \
> + _parents, \
> + &ccu_mp_ops, \
> + _flags), \
> + } \
> + }
> +

This looks suspiciously like a copy of the macro below. What about you
define the one below as a special case of this new one above?
Should be even more straightforward with defaulting postdiv to 1 and
loosing the feature flags.

Cheers,
Andre.

> #define SUNXI_CCU_MP_WITH_MUX_GATE(_struct, _name, _parents, _reg, \
> _mshift, _mwidth, \
> _pshift, _pwidth, \
>

\
 
 \ /
  Last update: 2017-12-05 00:19    [W:0.087 / U:3.580 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site