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209 lines
4.8 KiB
209 lines
4.8 KiB
/* |
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* mmp factor clock operation source file |
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* |
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* Copyright (C) 2012 Marvell |
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* Chao Xie <[email protected]> |
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* |
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* This file is licensed under the terms of the GNU General Public |
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* License version 2. This program is licensed "as is" without any |
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* warranty of any kind, whether express or implied. |
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*/ |
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#include <linux/clk-provider.h> |
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#include <linux/slab.h> |
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#include <linux/io.h> |
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#include <linux/err.h> |
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#include "clk.h" |
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/* |
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* It is M/N clock |
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* |
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* Fout from synthesizer can be given from two equations: |
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* numerator/denominator = Fin / (Fout * factor) |
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*/ |
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#define to_clk_factor(hw) container_of(hw, struct mmp_clk_factor, hw) |
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static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate, |
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unsigned long *prate) |
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{ |
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struct mmp_clk_factor *factor = to_clk_factor(hw); |
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u64 rate = 0, prev_rate; |
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int i; |
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for (i = 0; i < factor->ftbl_cnt; i++) { |
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prev_rate = rate; |
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rate = *prate; |
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rate *= factor->ftbl[i].den; |
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do_div(rate, factor->ftbl[i].num * factor->masks->factor); |
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if (rate > drate) |
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break; |
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} |
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if ((i == 0) || (i == factor->ftbl_cnt)) { |
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return rate; |
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} else { |
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if ((drate - prev_rate) > (rate - drate)) |
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return rate; |
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else |
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return prev_rate; |
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} |
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} |
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static unsigned long clk_factor_recalc_rate(struct clk_hw *hw, |
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unsigned long parent_rate) |
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{ |
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struct mmp_clk_factor *factor = to_clk_factor(hw); |
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struct mmp_clk_factor_masks *masks = factor->masks; |
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unsigned int val, num, den; |
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u64 rate; |
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val = readl_relaxed(factor->base); |
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/* calculate numerator */ |
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num = (val >> masks->num_shift) & masks->num_mask; |
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/* calculate denominator */ |
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den = (val >> masks->den_shift) & masks->den_mask; |
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if (!den) |
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return 0; |
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rate = parent_rate; |
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rate *= den; |
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do_div(rate, num * factor->masks->factor); |
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return rate; |
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} |
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/* Configures new clock rate*/ |
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static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate, |
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unsigned long prate) |
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{ |
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struct mmp_clk_factor *factor = to_clk_factor(hw); |
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struct mmp_clk_factor_masks *masks = factor->masks; |
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int i; |
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unsigned long val; |
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unsigned long flags = 0; |
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u64 rate = 0; |
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for (i = 0; i < factor->ftbl_cnt; i++) { |
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rate = prate; |
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rate *= factor->ftbl[i].den; |
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do_div(rate, factor->ftbl[i].num * factor->masks->factor); |
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if (rate > drate) |
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break; |
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} |
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if (i > 0) |
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i--; |
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if (factor->lock) |
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spin_lock_irqsave(factor->lock, flags); |
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val = readl_relaxed(factor->base); |
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val &= ~(masks->num_mask << masks->num_shift); |
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val |= (factor->ftbl[i].num & masks->num_mask) << masks->num_shift; |
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val &= ~(masks->den_mask << masks->den_shift); |
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val |= (factor->ftbl[i].den & masks->den_mask) << masks->den_shift; |
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writel_relaxed(val, factor->base); |
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if (factor->lock) |
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spin_unlock_irqrestore(factor->lock, flags); |
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return 0; |
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} |
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static int clk_factor_init(struct clk_hw *hw) |
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{ |
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struct mmp_clk_factor *factor = to_clk_factor(hw); |
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struct mmp_clk_factor_masks *masks = factor->masks; |
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u32 val, num, den; |
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int i; |
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unsigned long flags = 0; |
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if (factor->lock) |
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spin_lock_irqsave(factor->lock, flags); |
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val = readl(factor->base); |
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/* calculate numerator */ |
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num = (val >> masks->num_shift) & masks->num_mask; |
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/* calculate denominator */ |
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den = (val >> masks->den_shift) & masks->den_mask; |
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for (i = 0; i < factor->ftbl_cnt; i++) |
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if (den == factor->ftbl[i].den && num == factor->ftbl[i].num) |
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break; |
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if (i >= factor->ftbl_cnt) { |
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val &= ~(masks->num_mask << masks->num_shift); |
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val |= (factor->ftbl[0].num & masks->num_mask) << |
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masks->num_shift; |
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val &= ~(masks->den_mask << masks->den_shift); |
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val |= (factor->ftbl[0].den & masks->den_mask) << |
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masks->den_shift; |
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} |
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if (!(val & masks->enable_mask) || i >= factor->ftbl_cnt) { |
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val |= masks->enable_mask; |
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writel(val, factor->base); |
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} |
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if (factor->lock) |
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spin_unlock_irqrestore(factor->lock, flags); |
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return 0; |
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} |
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static const struct clk_ops clk_factor_ops = { |
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.recalc_rate = clk_factor_recalc_rate, |
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.round_rate = clk_factor_round_rate, |
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.set_rate = clk_factor_set_rate, |
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.init = clk_factor_init, |
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}; |
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struct clk *mmp_clk_register_factor(const char *name, const char *parent_name, |
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unsigned long flags, void __iomem *base, |
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struct mmp_clk_factor_masks *masks, |
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struct mmp_clk_factor_tbl *ftbl, |
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unsigned int ftbl_cnt, spinlock_t *lock) |
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{ |
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struct mmp_clk_factor *factor; |
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struct clk_init_data init; |
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struct clk *clk; |
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if (!masks) { |
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pr_err("%s: must pass a clk_factor_mask\n", __func__); |
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return ERR_PTR(-EINVAL); |
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} |
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factor = kzalloc(sizeof(*factor), GFP_KERNEL); |
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if (!factor) |
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return ERR_PTR(-ENOMEM); |
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/* struct clk_aux assignments */ |
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factor->base = base; |
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factor->masks = masks; |
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factor->ftbl = ftbl; |
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factor->ftbl_cnt = ftbl_cnt; |
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factor->hw.init = &init; |
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factor->lock = lock; |
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init.name = name; |
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init.ops = &clk_factor_ops; |
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init.flags = flags; |
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init.parent_names = &parent_name; |
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init.num_parents = 1; |
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clk = clk_register(NULL, &factor->hw); |
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if (IS_ERR_OR_NULL(clk)) |
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kfree(factor); |
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return clk; |
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}
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