1 /* 2 * Copyright (C) 2012 ST Microelectronics 3 * Viresh Kumar <vireshk@kernel.org> 4 * 5 * This file is licensed under the terms of the GNU General Public 6 * License version 2. This program is licensed "as is" without any 7 * warranty of any kind, whether express or implied. 8 * 9 * Auxiliary Synthesizer clock implementation 10 */ 11 12 #define pr_fmt(fmt) "clk-aux-synth: " fmt 13 14 #include <linux/clk-provider.h> 15 #include <linux/slab.h> 16 #include <linux/io.h> 17 #include <linux/err.h> 18 #include "clk.h" 19 20 /* 21 * DOC: Auxiliary Synthesizer clock 22 * 23 * Aux synth gives rate for different values of eq, x and y 24 * 25 * Fout from synthesizer can be given from two equations: 26 * Fout1 = (Fin * X/Y)/2 EQ1 27 * Fout2 = Fin * X/Y EQ2 28 */ 29 30 #define to_clk_aux(_hw) container_of(_hw, struct clk_aux, hw) 31 32 static struct aux_clk_masks default_aux_masks = { 33 .eq_sel_mask = AUX_EQ_SEL_MASK, 34 .eq_sel_shift = AUX_EQ_SEL_SHIFT, 35 .eq1_mask = AUX_EQ1_SEL, 36 .eq2_mask = AUX_EQ2_SEL, 37 .xscale_sel_mask = AUX_XSCALE_MASK, 38 .xscale_sel_shift = AUX_XSCALE_SHIFT, 39 .yscale_sel_mask = AUX_YSCALE_MASK, 40 .yscale_sel_shift = AUX_YSCALE_SHIFT, 41 .enable_bit = AUX_SYNT_ENB, 42 }; 43 44 static unsigned long aux_calc_rate(struct clk_hw *hw, unsigned long prate, 45 int index) 46 { 47 struct clk_aux *aux = to_clk_aux(hw); 48 struct aux_rate_tbl *rtbl = aux->rtbl; 49 u8 eq = rtbl[index].eq ? 1 : 2; 50 51 return (((prate / 10000) * rtbl[index].xscale) / 52 (rtbl[index].yscale * eq)) * 10000; 53 } 54 55 static long clk_aux_round_rate(struct clk_hw *hw, unsigned long drate, 56 unsigned long *prate) 57 { 58 struct clk_aux *aux = to_clk_aux(hw); 59 int unused; 60 61 return clk_round_rate_index(hw, drate, *prate, aux_calc_rate, 62 aux->rtbl_cnt, &unused); 63 } 64 65 static unsigned long clk_aux_recalc_rate(struct clk_hw *hw, 66 unsigned long parent_rate) 67 { 68 struct clk_aux *aux = to_clk_aux(hw); 69 unsigned int num = 1, den = 1, val, eqn; 70 unsigned long flags = 0; 71 72 if (aux->lock) 73 spin_lock_irqsave(aux->lock, flags); 74 75 val = readl_relaxed(aux->reg); 76 77 if (aux->lock) 78 spin_unlock_irqrestore(aux->lock, flags); 79 80 eqn = (val >> aux->masks->eq_sel_shift) & aux->masks->eq_sel_mask; 81 if (eqn == aux->masks->eq1_mask) 82 den = 2; 83 84 /* calculate numerator */ 85 num = (val >> aux->masks->xscale_sel_shift) & 86 aux->masks->xscale_sel_mask; 87 88 /* calculate denominator */ 89 den *= (val >> aux->masks->yscale_sel_shift) & 90 aux->masks->yscale_sel_mask; 91 92 if (!den) 93 return 0; 94 95 return (((parent_rate / 10000) * num) / den) * 10000; 96 } 97 98 /* Configures new clock rate of aux */ 99 static int clk_aux_set_rate(struct clk_hw *hw, unsigned long drate, 100 unsigned long prate) 101 { 102 struct clk_aux *aux = to_clk_aux(hw); 103 struct aux_rate_tbl *rtbl = aux->rtbl; 104 unsigned long val, flags = 0; 105 int i; 106 107 clk_round_rate_index(hw, drate, prate, aux_calc_rate, aux->rtbl_cnt, 108 &i); 109 110 if (aux->lock) 111 spin_lock_irqsave(aux->lock, flags); 112 113 val = readl_relaxed(aux->reg) & 114 ~(aux->masks->eq_sel_mask << aux->masks->eq_sel_shift); 115 val |= (rtbl[i].eq & aux->masks->eq_sel_mask) << 116 aux->masks->eq_sel_shift; 117 val &= ~(aux->masks->xscale_sel_mask << aux->masks->xscale_sel_shift); 118 val |= (rtbl[i].xscale & aux->masks->xscale_sel_mask) << 119 aux->masks->xscale_sel_shift; 120 val &= ~(aux->masks->yscale_sel_mask << aux->masks->yscale_sel_shift); 121 val |= (rtbl[i].yscale & aux->masks->yscale_sel_mask) << 122 aux->masks->yscale_sel_shift; 123 writel_relaxed(val, aux->reg); 124 125 if (aux->lock) 126 spin_unlock_irqrestore(aux->lock, flags); 127 128 return 0; 129 } 130 131 static struct clk_ops clk_aux_ops = { 132 .recalc_rate = clk_aux_recalc_rate, 133 .round_rate = clk_aux_round_rate, 134 .set_rate = clk_aux_set_rate, 135 }; 136 137 struct clk *clk_register_aux(const char *aux_name, const char *gate_name, 138 const char *parent_name, unsigned long flags, void __iomem *reg, 139 struct aux_clk_masks *masks, struct aux_rate_tbl *rtbl, 140 u8 rtbl_cnt, spinlock_t *lock, struct clk **gate_clk) 141 { 142 struct clk_aux *aux; 143 struct clk_init_data init; 144 struct clk *clk; 145 146 if (!aux_name || !parent_name || !reg || !rtbl || !rtbl_cnt) { 147 pr_err("Invalid arguments passed"); 148 return ERR_PTR(-EINVAL); 149 } 150 151 aux = kzalloc(sizeof(*aux), GFP_KERNEL); 152 if (!aux) { 153 pr_err("could not allocate aux clk\n"); 154 return ERR_PTR(-ENOMEM); 155 } 156 157 /* struct clk_aux assignments */ 158 if (!masks) 159 aux->masks = &default_aux_masks; 160 else 161 aux->masks = masks; 162 163 aux->reg = reg; 164 aux->rtbl = rtbl; 165 aux->rtbl_cnt = rtbl_cnt; 166 aux->lock = lock; 167 aux->hw.init = &init; 168 169 init.name = aux_name; 170 init.ops = &clk_aux_ops; 171 init.flags = flags; 172 init.parent_names = &parent_name; 173 init.num_parents = 1; 174 175 clk = clk_register(NULL, &aux->hw); 176 if (IS_ERR_OR_NULL(clk)) 177 goto free_aux; 178 179 if (gate_name) { 180 struct clk *tgate_clk; 181 182 tgate_clk = clk_register_gate(NULL, gate_name, aux_name, 183 CLK_SET_RATE_PARENT, reg, 184 aux->masks->enable_bit, 0, lock); 185 if (IS_ERR_OR_NULL(tgate_clk)) 186 goto free_aux; 187 188 if (gate_clk) 189 *gate_clk = tgate_clk; 190 } 191 192 return clk; 193 194 free_aux: 195 kfree(aux); 196 pr_err("clk register failed\n"); 197 198 return NULL; 199 } 200