2 * Copyright 2012 Freescale Semiconductor, Inc.
4 * The code contained herein is licensed under the GNU General Public
5 * License. You may obtain a copy of the GNU General Public License
6 * Version 2 or later at the following locations:
8 * http://www.opensource.org/licenses/gpl-license.html
9 * http://www.gnu.org/copyleft/gpl.html
12 #include <linux/clk-provider.h>
13 #include <linux/err.h>
15 #include <linux/slab.h>
19 * struct clk_frac - mxs fractional divider clock
20 * @hw: clk_hw for the fractional divider clock
21 * @reg: register address
22 * @shift: the divider bit shift
23 * @width: the divider bit width
24 * @busy: busy bit shift
26 * The clock is an adjustable fractional divider with a busy bit to wait
27 * when the divider is adjusted.
37 #define to_clk_frac(_hw) container_of(_hw, struct clk_frac, hw)
39 static unsigned long clk_frac_recalc_rate(struct clk_hw *hw,
40 unsigned long parent_rate)
42 struct clk_frac *frac = to_clk_frac(hw);
45 div = readl_relaxed(frac->reg) >> frac->shift;
46 div &= (1 << frac->width) - 1;
48 return (parent_rate >> frac->width) * div;
51 static long clk_frac_round_rate(struct clk_hw *hw, unsigned long rate,
54 struct clk_frac *frac = to_clk_frac(hw);
55 unsigned long parent_rate = *prate;
59 if (rate > parent_rate)
64 do_div(tmp, parent_rate);
70 return (parent_rate >> frac->width) * div;
73 static int clk_frac_set_rate(struct clk_hw *hw, unsigned long rate,
74 unsigned long parent_rate)
76 struct clk_frac *frac = to_clk_frac(hw);
81 if (rate > parent_rate)
86 do_div(tmp, parent_rate);
92 spin_lock_irqsave(&mxs_lock, flags);
94 val = readl_relaxed(frac->reg);
95 val &= ~(((1 << frac->width) - 1) << frac->shift);
96 val |= div << frac->shift;
97 writel_relaxed(val, frac->reg);
99 spin_unlock_irqrestore(&mxs_lock, flags);
101 return mxs_clk_wait(frac->reg, frac->busy);
104 static struct clk_ops clk_frac_ops = {
105 .recalc_rate = clk_frac_recalc_rate,
106 .round_rate = clk_frac_round_rate,
107 .set_rate = clk_frac_set_rate,
110 struct clk *mxs_clk_frac(const char *name, const char *parent_name,
111 void __iomem *reg, u8 shift, u8 width, u8 busy)
113 struct clk_frac *frac;
115 struct clk_init_data init;
117 frac = kzalloc(sizeof(*frac), GFP_KERNEL);
119 return ERR_PTR(-ENOMEM);
122 init.ops = &clk_frac_ops;
123 init.flags = CLK_SET_RATE_PARENT;
124 init.parent_names = (parent_name ? &parent_name: NULL);
125 init.num_parents = (parent_name ? 1 : 0);
131 frac->hw.init = &init;
133 clk = clk_register(NULL, &frac->hw);