diff options
author | Chao Xie <chao.xie@marvell.com> | 2012-08-20 02:55:11 (GMT) |
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committer | Mike Turquette <mturquette@linaro.org> | 2012-08-28 21:14:14 (GMT) |
commit | 6b63f023184e34b404b96bb9a8c4ac6692ff3fbd (patch) | |
tree | 1ad367ccdd9dcf6a87d2e30a32b910865ac14f52 /drivers/clk/mmp/clk-frac.c | |
parent | f9a6aa4303bd15bbdb24d9fe374e4e6850298460 (diff) | |
download | linux-fsl-qoriq-6b63f023184e34b404b96bb9a8c4ac6692ff3fbd.tar.xz |
clk: mmp: add mmp specific clocks
add mmp specific clocks including apbc cloks, apmu clocks,
and pll2, fraction clocks
Signed-off-by: Chao Xie <xiechao.mail@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/mmp/clk-frac.c')
-rw-r--r-- | drivers/clk/mmp/clk-frac.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/clk/mmp/clk-frac.c b/drivers/clk/mmp/clk-frac.c new file mode 100644 index 0000000..80c1dd1 --- /dev/null +++ b/drivers/clk/mmp/clk-frac.c @@ -0,0 +1,153 @@ +/* + * mmp factor clock operation source file + * + * Copyright (C) 2012 Marvell + * Chao Xie <xiechao.mail@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> + +#include "clk.h" +/* + * It is M/N clock + * + * Fout from synthesizer can be given from two equations: + * numerator/denominator = Fin / (Fout * factor) + */ + +#define to_clk_factor(hw) container_of(hw, struct clk_factor, hw) +struct clk_factor { + struct clk_hw hw; + void __iomem *base; + struct clk_factor_masks *masks; + struct clk_factor_tbl *ftbl; + unsigned int ftbl_cnt; +}; + +static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate, + unsigned long *prate) +{ + struct clk_factor *factor = to_clk_factor(hw); + unsigned long rate = 0, prev_rate; + int i; + + for (i = 0; i < factor->ftbl_cnt; i++) { + prev_rate = rate; + rate = (((*prate / 10000) * factor->ftbl[i].num) / + (factor->ftbl[i].den * factor->masks->factor)) * 10000; + if (rate > drate) + break; + } + if (i == 0) + return rate; + else + return prev_rate; +} + +static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_factor *factor = to_clk_factor(hw); + struct clk_factor_masks *masks = factor->masks; + unsigned int val, num, den; + + val = readl_relaxed(factor->base); + + /* calculate numerator */ + num = (val >> masks->num_shift) & masks->num_mask; + + /* calculate denominator */ + den = (val >> masks->den_shift) & masks->num_mask; + + if (!den) + return 0; + + return (((parent_rate / 10000) * den) / + (num * factor->masks->factor)) * 10000; +} + +/* Configures new clock rate*/ +static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate, + unsigned long prate) +{ + struct clk_factor *factor = to_clk_factor(hw); + struct clk_factor_masks *masks = factor->masks; + int i; + unsigned long val; + unsigned long prev_rate, rate = 0; + + for (i = 0; i < factor->ftbl_cnt; i++) { + prev_rate = rate; + rate = (((prate / 10000) * factor->ftbl[i].num) / + (factor->ftbl[i].den * factor->masks->factor)) * 10000; + if (rate > drate) + break; + } + if (i > 0) + i--; + + val = readl_relaxed(factor->base); + + val &= ~(masks->num_mask << masks->num_shift); + val |= (factor->ftbl[i].num & masks->num_mask) << masks->num_shift; + + val &= ~(masks->den_mask << masks->den_shift); + val |= (factor->ftbl[i].den & masks->den_mask) << masks->den_shift; + + writel_relaxed(val, factor->base); + + return 0; +} + +static struct clk_ops clk_factor_ops = { + .recalc_rate = clk_factor_recalc_rate, + .round_rate = clk_factor_round_rate, + .set_rate = clk_factor_set_rate, +}; + +struct clk *mmp_clk_register_factor(const char *name, const char *parent_name, + unsigned long flags, void __iomem *base, + struct clk_factor_masks *masks, struct clk_factor_tbl *ftbl, + unsigned int ftbl_cnt) +{ + struct clk_factor *factor; + struct clk_init_data init; + struct clk *clk; + + if (!masks) { + pr_err("%s: must pass a clk_factor_mask\n", __func__); + return ERR_PTR(-EINVAL); + } + + factor = kzalloc(sizeof(*factor), GFP_KERNEL); + if (!factor) { + pr_err("%s: could not allocate factor clk\n", __func__); + return ERR_PTR(-ENOMEM); + } + + /* struct clk_aux assignments */ + factor->base = base; + factor->masks = masks; + factor->ftbl = ftbl; + factor->ftbl_cnt = ftbl_cnt; + factor->hw.init = &init; + + init.name = name; + init.ops = &clk_factor_ops; + init.flags = flags; + init.parent_names = &parent_name; + init.num_parents = 1; + + clk = clk_register(NULL, &factor->hw); + if (IS_ERR_OR_NULL(clk)) + kfree(factor); + + return clk; +} |