Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 | /* * Copyright (c) 2014 Lucas Stach <l.stach@pengutronix.de>, Pengutronix * * 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. * * http://www.opensource.org/licenses/gpl-license.html * http://www.gnu.org/copyleft/gpl.html */ #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/slab.h> #include "clk.h" struct clk_cpu { struct clk_hw hw; struct clk *div; struct clk *mux; struct clk *pll; struct clk *step; }; static inline struct clk_cpu *to_clk_cpu(struct clk_hw *hw) { return container_of(hw, struct clk_cpu, hw); } static unsigned long clk_cpu_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_cpu *cpu = to_clk_cpu(hw); return clk_get_rate(cpu->div); } static long clk_cpu_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { struct clk_cpu *cpu = to_clk_cpu(hw); return clk_round_rate(cpu->pll, rate); } static int clk_cpu_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct clk_cpu *cpu = to_clk_cpu(hw); int ret; /* switch to PLL bypass clock */ ret = clk_set_parent(cpu->mux, cpu->step); if (ret) return ret; /* reprogram PLL */ ret = clk_set_rate(cpu->pll, rate); if (ret) { clk_set_parent(cpu->mux, cpu->pll); return ret; } /* switch back to PLL clock */ clk_set_parent(cpu->mux, cpu->pll); /* Ensure the divider is what we expect */ clk_set_rate(cpu->div, rate); return 0; } static const struct clk_ops clk_cpu_ops = { .recalc_rate = clk_cpu_recalc_rate, .round_rate = clk_cpu_round_rate, .set_rate = clk_cpu_set_rate, }; struct clk *imx_clk_cpu(const char *name, const char *parent_name, struct clk *div, struct clk *mux, struct clk *pll, struct clk *step) { struct clk_cpu *cpu; struct clk *clk; struct clk_init_data init; cpu = kzalloc(sizeof(*cpu), GFP_KERNEL); if (!cpu) return ERR_PTR(-ENOMEM); cpu->div = div; cpu->mux = mux; cpu->pll = pll; cpu->step = step; init.name = name; init.ops = &clk_cpu_ops; init.flags = 0; init.parent_names = &parent_name; init.num_parents = 1; cpu->hw.init = &init; clk = clk_register(NULL, &cpu->hw); if (IS_ERR(clk)) kfree(cpu); return clk; } |