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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> */ #include <linux/clk-provider.h> #include <linux/clkdev.h> #include <linux/clk/at91_pmc.h> #include <linux/of.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> #include <soc/at91/atmel-sfr.h> #include "pmc.h" /* * The purpose of this clock is to generate a 480 MHz signal. A different * rate can't be configured. */ #define UTMI_RATE 480000000 struct clk_utmi { struct clk_hw hw; struct regmap *regmap_pmc; struct regmap *regmap_sfr; }; #define to_clk_utmi(hw) container_of(hw, struct clk_utmi, hw) static inline bool clk_utmi_ready(struct regmap *regmap) { unsigned int status; regmap_read(regmap, AT91_PMC_SR, &status); return status & AT91_PMC_LOCKU; } static int clk_utmi_prepare(struct clk_hw *hw) { struct clk_hw *hw_parent; struct clk_utmi *utmi = to_clk_utmi(hw); unsigned int uckr = AT91_PMC_UPLLEN | AT91_PMC_UPLLCOUNT | AT91_PMC_BIASEN; unsigned int utmi_ref_clk_freq; unsigned long parent_rate; /* * If mainck rate is different from 12 MHz, we have to configure the * FREQ field of the SFR_UTMICKTRIM register to generate properly * the utmi clock. */ hw_parent = clk_hw_get_parent(hw); parent_rate = clk_hw_get_rate(hw_parent); switch (parent_rate) { case 12000000: utmi_ref_clk_freq = 0; break; case 16000000: utmi_ref_clk_freq = 1; break; case 24000000: utmi_ref_clk_freq = 2; break; /* * Not supported on SAMA5D2 but it's not an issue since MAINCK * maximum value is 24 MHz. */ case 48000000: utmi_ref_clk_freq = 3; break; default: pr_err("UTMICK: unsupported mainck rate\n"); return -EINVAL; } if (utmi->regmap_sfr) { regmap_update_bits(utmi->regmap_sfr, AT91_SFR_UTMICKTRIM, AT91_UTMICKTRIM_FREQ, utmi_ref_clk_freq); } else if (utmi_ref_clk_freq) { pr_err("UTMICK: sfr node required\n"); return -EINVAL; } regmap_update_bits(utmi->regmap_pmc, AT91_CKGR_UCKR, uckr, uckr); while (!clk_utmi_ready(utmi->regmap_pmc)) cpu_relax(); return 0; } static int clk_utmi_is_prepared(struct clk_hw *hw) { struct clk_utmi *utmi = to_clk_utmi(hw); return clk_utmi_ready(utmi->regmap_pmc); } static void clk_utmi_unprepare(struct clk_hw *hw) { struct clk_utmi *utmi = to_clk_utmi(hw); regmap_update_bits(utmi->regmap_pmc, AT91_CKGR_UCKR, AT91_PMC_UPLLEN, 0); } static unsigned long clk_utmi_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { /* UTMI clk rate is fixed. */ return UTMI_RATE; } static const struct clk_ops utmi_ops = { .prepare = clk_utmi_prepare, .unprepare = clk_utmi_unprepare, .is_prepared = clk_utmi_is_prepared, .recalc_rate = clk_utmi_recalc_rate, }; struct clk_hw * __init at91_clk_register_utmi(struct regmap *regmap_pmc, struct regmap *regmap_sfr, const char *name, const char *parent_name) { struct clk_utmi *utmi; struct clk_hw *hw; struct clk_init_data init; int ret; utmi = kzalloc(sizeof(*utmi), GFP_KERNEL); if (!utmi) return ERR_PTR(-ENOMEM); init.name = name; init.ops = &utmi_ops; init.parent_names = parent_name ? &parent_name : NULL; init.num_parents = parent_name ? 1 : 0; init.flags = CLK_SET_RATE_GATE; utmi->hw.init = &init; utmi->regmap_pmc = regmap_pmc; utmi->regmap_sfr = regmap_sfr; hw = &utmi->hw; ret = clk_hw_register(NULL, &utmi->hw); if (ret) { kfree(utmi); hw = ERR_PTR(ret); } return hw; } |