Re: [PATCH v2 11/15] clk: sunxi-ng: Add N-M-factor clock support
From: Jean-Francois Moine <hidden>
Date: 2016-06-09 07:41:20
Also in:
linux-arm-kernel, linux-clk, lkml
On Tue, 7 Jun 2016 22:41:50 +0200 Maxime Ripard [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Introduce support for clocks that multiply and divide using linear factors. Signed-off-by: Maxime Ripard <redacted> --- Changes from v1: - Fixed the maximums for both factors passed to the rational factor computation. --- drivers/clk/sunxi-ng/Makefile | 1 + drivers/clk/sunxi-ng/ccu_nm.c | 114 ++++++++++++++++++++++++++++++++++++++++++ drivers/clk/sunxi-ng/ccu_nm.h | 95 +++++++++++++++++++++++++++++++++++ 3 files changed, 210 insertions(+) create mode 100644 drivers/clk/sunxi-ng/ccu_nm.c create mode 100644 drivers/clk/sunxi-ng/ccu_nm.hdiff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile index a201fad6b11d..5c7ae1ad1082 100644 --- a/drivers/clk/sunxi-ng/Makefile +++ b/drivers/clk/sunxi-ng/Makefile@@ -9,4 +9,5 @@ obj-y += ccu_gate.o obj-y += ccu_mp.o obj-y += ccu_mux.o obj-y += ccu_nk.o +obj-y += ccu_nm.o obj-y += ccu_phase.odiff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c new file mode 100644 index 000000000000..e35ddd8eec8b --- /dev/null +++ b/drivers/clk/sunxi-ng/ccu_nm.c@@ -0,0 +1,114 @@ +/* + * 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_frac.h" +#include "ccu_gate.h" +#include "ccu_nm.h"
[snip]
+static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ unsigned long n, m;
+ u32 reg;
+
+ if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac))
+ return ccu_frac_helper_read_rate(&nm->common, &nm->frac);
+
+ reg = readl(nm->common.base + nm->common.reg);
+
+ n = reg >> nm->n.shift;
+ n &= (1 << nm->n.width) - 1;
+
+ m = reg >> nm->m.shift;
+ m &= (1 << nm->m.width) - 1;
+
+ return parent_rate * (n + 1) / (m + 1);In the H3, 'm' is a pre-divider (audio and video PLLs): return parent_rate / (m + 1) * (n + 1);
+}
+
+static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct ccu_nm *nm = hw_to_ccu_nm(hw);
+ unsigned long n, m;
+
+ rational_best_approximation(rate, *parent_rate,
+ 1 << nm->n.width, 1 << nm->m.width,
+ &n, &m);
+
+ return *parent_rate * n / m;Same here.
+}
+
+static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{[snip] -- Ken ar c'hentañ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/