Re: [PATCH 13/16] clk: sunxi-ng: Add N-K-M Factor clock

Maxime Ripard
2016-05-15T19:08:18Z

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On Wed, May 11, 2016 at 10:45:56AM +0200, Jean-Francois Moine wrote:
> On Sun, 8 May 2016 22:01:48 +0200
> Maxime Ripard <maxime.ripard@free-electrons.com> wrote:
>
> > Introduce support for clocks that multiply and divide using two linear
> > multipliers and one linear divider.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> > drivers/clk/sunxi-ng/Makefile | 1 +
> > drivers/clk/sunxi-ng/ccu_nkm.c | 144 +++++++++++++++++++++++++++++++++++++++++
> > drivers/clk/sunxi-ng/ccu_nkm.h | 42 ++++++++++++
> > 3 files changed, 187 insertions(+)
> > create mode 100644 drivers/clk/sunxi-ng/ccu_nkm.c
> > create mode 100644 drivers/clk/sunxi-ng/ccu_nkm.h
> >
> > diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile
> > index fba64c7f4fcd..2bb8bc22e907 100644
> > --- a/drivers/clk/sunxi-ng/Makefile
> > +++ b/drivers/clk/sunxi-ng/Makefile
> > @@ -8,6 +8,7 @@ obj-y += ccu_m.o
> > obj-y += ccu_mp.o
> > obj-y += ccu_mux.o
> > obj-y += ccu_nk.o
> > +obj-y += ccu_nkm.o
> > obj-y += ccu_nm.o
> > obj-y += ccu_p.o
> > obj-y += ccu_phase.o
> > diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> > new file mode 100644
> > index 000000000000..9019c7f6988c
> > --- /dev/null
> > +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> [snip]
> > @@ -0,0 +1,144 @@
> > +/*
> > + * Copyright (C) 2016 Maxime Ripard
> > + * Maxime Ripard <maxime.ripard@free-electrons.com>
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License as
> > + * published by the Free Software Foundation; either version 2 of
> > + * the License, or (at your option) any later version.
> > + */
> > +
> > +#include <linux/clk-provider.h>
> > +#include <linux/rational.h>
> > +
> > +#include "ccu_gate.h"
> > +#include "ccu_nkm.h"
> > +
> > +void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
> > + unsigned long max_n, unsigned long max_k, unsigned long max_m,
> > + unsigned long *n, unsigned long *k, unsigned long *m)
>
> Should be static
>
> [snip]
>
> > +static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
> > + unsigned long parent_rate)
> > +{
> > + struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
> > + unsigned long n, k, m;
> > + unsigned long flags;
> > + u32 reg;
> > +
> > + ccu_nkm_find_best(parent_rate, rate, 1 << nkm->n.width,
> > + 1 << nkm->k.width, 1 << nkm->m.width,
> > + &n, &k, &m);
> > +
> > + spin_lock_irqsave(nkm->common.lock, flags);
> > +
> > + reg = readl(nkm->common.base + nkm->common.reg);
> > + reg &= ~GENMASK(nkm->n.width + nkm->n.shift, nkm->n.shift);
> > + reg &= ~GENMASK(nkm->k.width + nkm->k.shift, nkm->k.shift);
> > + reg &= ~GENMASK(nkm->m.width + nkm->m.shift, nkm->m.shift);
> > +
> > + reg |= (n - 1) << nkm->m.shift;
> > + reg |= (k - 1) << nkm->m.shift;
> > + reg |= (m - 1) << nkm->m.shift;
>
> reg |= (n - 1) << nkm->n.shift;
> reg |= (k - 1) << nkm->k.shift;

Good catches, thanks!
Maxime

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

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