From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/drivers/clk/clk-multiplier.c | 130 ++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 kernel/drivers/clk/clk-multiplier.c (limited to 'kernel/drivers/clk/clk-multiplier.c') diff --git a/kernel/drivers/clk/clk-multiplier.c b/kernel/drivers/clk/clk-multiplier.c new file mode 100644 index 000000000..fe7806506 --- /dev/null +++ b/kernel/drivers/clk/clk-multiplier.c @@ -0,0 +1,130 @@ +/* + * Copyright (C) 2015 Maxime Ripard + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define to_clk_multiplier(_hw) container_of(_hw, struct clk_multiplier, hw) + +static unsigned long __get_mult(struct clk_multiplier *mult, + unsigned long rate, + unsigned long parent_rate) +{ + if (mult->flags & CLK_MULTIPLIER_ROUND_CLOSEST) + return DIV_ROUND_CLOSEST(rate, parent_rate); + + return rate / parent_rate; +} + +static unsigned long clk_multiplier_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_multiplier *mult = to_clk_multiplier(hw); + unsigned long val; + + val = clk_readl(mult->reg) >> mult->shift; + val &= GENMASK(mult->width - 1, 0); + + if (!val && mult->flags & CLK_MULTIPLIER_ZERO_BYPASS) + val = 1; + + return parent_rate * val; +} + +static bool __is_best_rate(unsigned long rate, unsigned long new, + unsigned long best, unsigned long flags) +{ + if (flags & CLK_MULTIPLIER_ROUND_CLOSEST) + return abs(rate - new) < abs(rate - best); + + return new >= rate && new < best; +} + +static unsigned long __bestmult(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + u8 width, unsigned long flags) +{ + unsigned long orig_parent_rate = *best_parent_rate; + unsigned long parent_rate, current_rate, best_rate = ~0; + unsigned int i, bestmult = 0; + + if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) + return rate / *best_parent_rate; + + for (i = 1; i < ((1 << width) - 1); i++) { + if (rate == orig_parent_rate * i) { + /* + * This is the best case for us if we have a + * perfect match without changing the parent + * rate. + */ + *best_parent_rate = orig_parent_rate; + return i; + } + + parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), + rate / i); + current_rate = parent_rate * i; + + if (__is_best_rate(rate, current_rate, best_rate, flags)) { + bestmult = i; + best_rate = current_rate; + *best_parent_rate = parent_rate; + } + } + + return bestmult; +} + +static long clk_multiplier_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct clk_multiplier *mult = to_clk_multiplier(hw); + unsigned long factor = __bestmult(hw, rate, parent_rate, + mult->width, mult->flags); + + return *parent_rate * factor; +} + +static int clk_multiplier_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_multiplier *mult = to_clk_multiplier(hw); + unsigned long factor = __get_mult(mult, rate, parent_rate); + unsigned long flags = 0; + unsigned long val; + + if (mult->lock) + spin_lock_irqsave(mult->lock, flags); + else + __acquire(mult->lock); + + val = clk_readl(mult->reg); + val &= ~GENMASK(mult->width + mult->shift - 1, mult->shift); + val |= factor << mult->shift; + clk_writel(val, mult->reg); + + if (mult->lock) + spin_unlock_irqrestore(mult->lock, flags); + else + __release(mult->lock); + + return 0; +} + +const struct clk_ops clk_multiplier_ops = { + .recalc_rate = clk_multiplier_recalc_rate, + .round_rate = clk_multiplier_round_rate, + .set_rate = clk_multiplier_set_rate, +}; +EXPORT_SYMBOL_GPL(clk_multiplier_ops); -- cgit 1.2.3-korg