1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * R-Car Gen3 Clock Pulse Generator Library 4 * 5 * Copyright (C) 2015-2018 Glider bvba 6 * Copyright (C) 2019 Renesas Electronics Corp. 7 * 8 * Based on clk-rcar-gen3.c 9 * 10 * Copyright (C) 2015 Renesas Electronics Corp. 11 */ 12 13 #include <linux/clk.h> 14 #include <linux/clk-provider.h> 15 #include <linux/device.h> 16 #include <linux/err.h> 17 #include <linux/init.h> 18 #include <linux/io.h> 19 #include <linux/pm.h> 20 #include <linux/slab.h> 21 #include <linux/sys_soc.h> 22 23 #include "rcar-cpg-lib.h" 24 25 spinlock_t cpg_lock; 26 27 void cpg_reg_modify(void __iomem *reg, u32 clear, u32 set) 28 { 29 unsigned long flags; 30 u32 val; 31 32 spin_lock_irqsave(&cpg_lock, flags); 33 val = readl(reg); 34 val &= ~clear; 35 val |= set; 36 writel(val, reg); 37 spin_unlock_irqrestore(&cpg_lock, flags); 38 }; 39 40 static int cpg_simple_notifier_call(struct notifier_block *nb, 41 unsigned long action, void *data) 42 { 43 struct cpg_simple_notifier *csn = 44 container_of(nb, struct cpg_simple_notifier, nb); 45 46 switch (action) { 47 case PM_EVENT_SUSPEND: 48 csn->saved = readl(csn->reg); 49 return NOTIFY_OK; 50 51 case PM_EVENT_RESUME: 52 writel(csn->saved, csn->reg); 53 return NOTIFY_OK; 54 } 55 return NOTIFY_DONE; 56 } 57 58 void cpg_simple_notifier_register(struct raw_notifier_head *notifiers, 59 struct cpg_simple_notifier *csn) 60 { 61 csn->nb.notifier_call = cpg_simple_notifier_call; 62 raw_notifier_chain_register(notifiers, &csn->nb); 63 } 64 65 /* 66 * SDn Clock 67 */ 68 #define CPG_SD_STP_HCK BIT(9) 69 #define CPG_SD_STP_CK BIT(8) 70 71 #define CPG_SD_STP_MASK (CPG_SD_STP_HCK | CPG_SD_STP_CK) 72 #define CPG_SD_FC_MASK (0x7 << 2 | 0x3 << 0) 73 74 #define CPG_SD_DIV_TABLE_DATA(stp_hck, sd_srcfc, sd_fc, sd_div) \ 75 { \ 76 .val = ((stp_hck) ? CPG_SD_STP_HCK : 0) | \ 77 ((sd_srcfc) << 2) | \ 78 ((sd_fc) << 0), \ 79 .div = (sd_div), \ 80 } 81 82 struct sd_div_table { 83 u32 val; 84 unsigned int div; 85 }; 86 87 struct sd_clock { 88 struct clk_hw hw; 89 const struct sd_div_table *div_table; 90 struct cpg_simple_notifier csn; 91 unsigned int div_num; 92 unsigned int cur_div_idx; 93 }; 94 95 /* SDn divider 96 * sd_srcfc sd_fc div 97 * stp_hck (div) (div) = sd_srcfc x sd_fc 98 *--------------------------------------------------------- 99 * 0 0 (1) 1 (4) 4 : SDR104 / HS200 / HS400 (8 TAP) 100 * 0 1 (2) 1 (4) 8 : SDR50 101 * 1 2 (4) 1 (4) 16 : HS / SDR25 102 * 1 3 (8) 1 (4) 32 : NS / SDR12 103 * 1 4 (16) 1 (4) 64 104 * 0 0 (1) 0 (2) 2 105 * 0 1 (2) 0 (2) 4 : SDR104 / HS200 / HS400 (4 TAP) 106 * 1 2 (4) 0 (2) 8 107 * 1 3 (8) 0 (2) 16 108 * 1 4 (16) 0 (2) 32 109 * 110 * NOTE: There is a quirk option to ignore the first row of the dividers 111 * table when searching for suitable settings. This is because HS400 on 112 * early ES versions of H3 and M3-W requires a specific setting to work. 113 */ 114 static const struct sd_div_table cpg_sd_div_table[] = { 115 /* CPG_SD_DIV_TABLE_DATA(stp_hck, sd_srcfc, sd_fc, sd_div) */ 116 CPG_SD_DIV_TABLE_DATA(0, 0, 1, 4), 117 CPG_SD_DIV_TABLE_DATA(0, 1, 1, 8), 118 CPG_SD_DIV_TABLE_DATA(1, 2, 1, 16), 119 CPG_SD_DIV_TABLE_DATA(1, 3, 1, 32), 120 CPG_SD_DIV_TABLE_DATA(1, 4, 1, 64), 121 CPG_SD_DIV_TABLE_DATA(0, 0, 0, 2), 122 CPG_SD_DIV_TABLE_DATA(0, 1, 0, 4), 123 CPG_SD_DIV_TABLE_DATA(1, 2, 0, 8), 124 CPG_SD_DIV_TABLE_DATA(1, 3, 0, 16), 125 CPG_SD_DIV_TABLE_DATA(1, 4, 0, 32), 126 }; 127 128 #define to_sd_clock(_hw) container_of(_hw, struct sd_clock, hw) 129 130 static int cpg_sd_clock_enable(struct clk_hw *hw) 131 { 132 struct sd_clock *clock = to_sd_clock(hw); 133 134 cpg_reg_modify(clock->csn.reg, CPG_SD_STP_MASK, 135 clock->div_table[clock->cur_div_idx].val & 136 CPG_SD_STP_MASK); 137 138 return 0; 139 } 140 141 static void cpg_sd_clock_disable(struct clk_hw *hw) 142 { 143 struct sd_clock *clock = to_sd_clock(hw); 144 145 cpg_reg_modify(clock->csn.reg, 0, CPG_SD_STP_MASK); 146 } 147 148 static int cpg_sd_clock_is_enabled(struct clk_hw *hw) 149 { 150 struct sd_clock *clock = to_sd_clock(hw); 151 152 return !(readl(clock->csn.reg) & CPG_SD_STP_MASK); 153 } 154 155 static unsigned long cpg_sd_clock_recalc_rate(struct clk_hw *hw, 156 unsigned long parent_rate) 157 { 158 struct sd_clock *clock = to_sd_clock(hw); 159 160 return DIV_ROUND_CLOSEST(parent_rate, 161 clock->div_table[clock->cur_div_idx].div); 162 } 163 164 static int cpg_sd_clock_determine_rate(struct clk_hw *hw, 165 struct clk_rate_request *req) 166 { 167 unsigned long best_rate = ULONG_MAX, diff_min = ULONG_MAX; 168 struct sd_clock *clock = to_sd_clock(hw); 169 unsigned long calc_rate, diff; 170 unsigned int i; 171 172 for (i = 0; i < clock->div_num; i++) { 173 calc_rate = DIV_ROUND_CLOSEST(req->best_parent_rate, 174 clock->div_table[i].div); 175 if (calc_rate < req->min_rate || calc_rate > req->max_rate) 176 continue; 177 178 diff = calc_rate > req->rate ? calc_rate - req->rate 179 : req->rate - calc_rate; 180 if (diff < diff_min) { 181 best_rate = calc_rate; 182 diff_min = diff; 183 } 184 } 185 186 if (best_rate == ULONG_MAX) 187 return -EINVAL; 188 189 req->rate = best_rate; 190 return 0; 191 } 192 193 static int cpg_sd_clock_set_rate(struct clk_hw *hw, unsigned long rate, 194 unsigned long parent_rate) 195 { 196 struct sd_clock *clock = to_sd_clock(hw); 197 unsigned int i; 198 199 for (i = 0; i < clock->div_num; i++) 200 if (rate == DIV_ROUND_CLOSEST(parent_rate, 201 clock->div_table[i].div)) 202 break; 203 204 if (i >= clock->div_num) 205 return -EINVAL; 206 207 clock->cur_div_idx = i; 208 209 cpg_reg_modify(clock->csn.reg, CPG_SD_STP_MASK | CPG_SD_FC_MASK, 210 clock->div_table[i].val & 211 (CPG_SD_STP_MASK | CPG_SD_FC_MASK)); 212 213 return 0; 214 } 215 216 static const struct clk_ops cpg_sd_clock_ops = { 217 .enable = cpg_sd_clock_enable, 218 .disable = cpg_sd_clock_disable, 219 .is_enabled = cpg_sd_clock_is_enabled, 220 .recalc_rate = cpg_sd_clock_recalc_rate, 221 .determine_rate = cpg_sd_clock_determine_rate, 222 .set_rate = cpg_sd_clock_set_rate, 223 }; 224 225 struct clk * __init cpg_sd_clk_register(const char *name, 226 void __iomem *base, unsigned int offset, const char *parent_name, 227 struct raw_notifier_head *notifiers, bool skip_first) 228 { 229 struct clk_init_data init; 230 struct sd_clock *clock; 231 struct clk *clk; 232 u32 val; 233 234 clock = kzalloc(sizeof(*clock), GFP_KERNEL); 235 if (!clock) 236 return ERR_PTR(-ENOMEM); 237 238 init.name = name; 239 init.ops = &cpg_sd_clock_ops; 240 init.flags = CLK_SET_RATE_PARENT; 241 init.parent_names = &parent_name; 242 init.num_parents = 1; 243 244 clock->csn.reg = base + offset; 245 clock->hw.init = &init; 246 clock->div_table = cpg_sd_div_table; 247 clock->div_num = ARRAY_SIZE(cpg_sd_div_table); 248 249 if (skip_first) { 250 clock->div_table++; 251 clock->div_num--; 252 } 253 254 val = readl(clock->csn.reg) & ~CPG_SD_FC_MASK; 255 val |= CPG_SD_STP_MASK | (clock->div_table[0].val & CPG_SD_FC_MASK); 256 writel(val, clock->csn.reg); 257 258 clk = clk_register(NULL, &clock->hw); 259 if (IS_ERR(clk)) 260 goto free_clock; 261 262 cpg_simple_notifier_register(notifiers, &clock->csn); 263 return clk; 264 265 free_clock: 266 kfree(clock); 267 return clk; 268 } 269 270 271