| /* |
| * 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 mmp_clk_factor, hw) |
| |
| static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate, |
| unsigned long *prate) |
| { |
| struct mmp_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].den) / |
| (factor->ftbl[i].num * factor->masks->factor)) * 10000; |
| if (rate > drate) |
| break; |
| } |
| if ((i == 0) || (i == factor->ftbl_cnt)) { |
| return rate; |
| } else { |
| if ((drate - prev_rate) > (rate - drate)) |
| return rate; |
| else |
| return prev_rate; |
| } |
| } |
| |
| static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, |
| unsigned long parent_rate) |
| { |
| struct mmp_clk_factor *factor = to_clk_factor(hw); |
| struct mmp_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->den_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 mmp_clk_factor *factor = to_clk_factor(hw); |
| struct mmp_clk_factor_masks *masks = factor->masks; |
| int i; |
| unsigned long val; |
| unsigned long prev_rate, rate = 0; |
| unsigned long flags = 0; |
| |
| for (i = 0; i < factor->ftbl_cnt; i++) { |
| prev_rate = rate; |
| rate = (((prate / 10000) * factor->ftbl[i].den) / |
| (factor->ftbl[i].num * factor->masks->factor)) * 10000; |
| if (rate > drate) |
| break; |
| } |
| if (i > 0) |
| i--; |
| |
| if (factor->lock) |
| spin_lock_irqsave(factor->lock, flags); |
| |
| 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); |
| |
| if (factor->lock) |
| spin_unlock_irqrestore(factor->lock, flags); |
| |
| return 0; |
| } |
| |
| void clk_factor_init(struct clk_hw *hw) |
| { |
| struct mmp_clk_factor *factor = to_clk_factor(hw); |
| struct mmp_clk_factor_masks *masks = factor->masks; |
| u32 val, num, den; |
| int i; |
| unsigned long flags = 0; |
| |
| if (factor->lock) |
| spin_lock_irqsave(factor->lock, flags); |
| |
| val = readl(factor->base); |
| |
| /* calculate numerator */ |
| num = (val >> masks->num_shift) & masks->num_mask; |
| |
| /* calculate denominator */ |
| den = (val >> masks->den_shift) & masks->den_mask; |
| |
| for (i = 0; i < factor->ftbl_cnt; i++) |
| if (den == factor->ftbl[i].den && num == factor->ftbl[i].num) |
| break; |
| |
| if (i >= factor->ftbl_cnt) { |
| val &= ~(masks->num_mask << masks->num_shift); |
| val |= (factor->ftbl[0].num & masks->num_mask) << |
| masks->num_shift; |
| |
| val &= ~(masks->den_mask << masks->den_shift); |
| val |= (factor->ftbl[0].den & masks->den_mask) << |
| masks->den_shift; |
| |
| writel(val, factor->base); |
| } |
| |
| if (factor->lock) |
| spin_unlock_irqrestore(factor->lock, flags); |
| } |
| |
| 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, |
| .init = clk_factor_init, |
| }; |
| |
| struct clk *mmp_clk_register_factor(const char *name, const char *parent_name, |
| unsigned long flags, void __iomem *base, |
| struct mmp_clk_factor_masks *masks, |
| struct mmp_clk_factor_tbl *ftbl, |
| unsigned int ftbl_cnt, spinlock_t *lock) |
| { |
| struct mmp_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; |
| factor->lock = lock; |
| |
| 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; |
| } |