1 /* 2 * Copyright 2013 Emilio López 3 * 4 * Emilio López <emilio@elopez.com.ar> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <linux/clk-provider.h> 18 #include <linux/clkdev.h> 19 #include <linux/of_address.h> 20 21 #include "clk-factors.h" 22 23 /** 24 * sun4i_get_mod0_factors() - calculates m, n factors for MOD0-style clocks 25 * MOD0 rate is calculated as follows 26 * rate = (parent_rate >> p) / (m + 1); 27 */ 28 29 static void sun4i_a10_get_mod0_factors(u32 *freq, u32 parent_rate, 30 u8 *n, u8 *k, u8 *m, u8 *p) 31 { 32 u8 div, calcm, calcp; 33 34 /* These clocks can only divide, so we will never be able to achieve 35 * frequencies higher than the parent frequency */ 36 if (*freq > parent_rate) 37 *freq = parent_rate; 38 39 div = DIV_ROUND_UP(parent_rate, *freq); 40 41 if (div < 16) 42 calcp = 0; 43 else if (div / 2 < 16) 44 calcp = 1; 45 else if (div / 4 < 16) 46 calcp = 2; 47 else 48 calcp = 3; 49 50 calcm = DIV_ROUND_UP(div, 1 << calcp); 51 52 *freq = (parent_rate >> calcp) / calcm; 53 54 /* we were called to round the frequency, we can now return */ 55 if (n == NULL) 56 return; 57 58 *m = calcm - 1; 59 *p = calcp; 60 } 61 62 /* user manual says "n" but it's really "p" */ 63 static struct clk_factors_config sun4i_a10_mod0_config = { 64 .mshift = 0, 65 .mwidth = 4, 66 .pshift = 16, 67 .pwidth = 2, 68 }; 69 70 static const struct factors_data sun4i_a10_mod0_data __initconst = { 71 .enable = 31, 72 .mux = 24, 73 .table = &sun4i_a10_mod0_config, 74 .getter = sun4i_a10_get_mod0_factors, 75 }; 76 77 static DEFINE_SPINLOCK(sun4i_a10_mod0_lock); 78 79 static void __init sun4i_a10_mod0_setup(struct device_node *node) 80 { 81 sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun4i_a10_mod0_lock); 82 } 83 CLK_OF_DECLARE(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk", sun4i_a10_mod0_setup); 84 85 static DEFINE_SPINLOCK(sun5i_a13_mbus_lock); 86 87 static void __init sun5i_a13_mbus_setup(struct device_node *node) 88 { 89 struct clk *mbus = sunxi_factors_register(node, &sun4i_a10_mod0_data, &sun5i_a13_mbus_lock); 90 91 /* The MBUS clocks needs to be always enabled */ 92 __clk_get(mbus); 93 clk_prepare_enable(mbus); 94 } 95 CLK_OF_DECLARE(sun5i_a13_mbus, "allwinner,sun5i-a13-mbus-clk", sun5i_a13_mbus_setup); 96 97 struct mmc_phase_data { 98 u8 offset; 99 }; 100 101 struct mmc_phase { 102 struct clk_hw hw; 103 void __iomem *reg; 104 struct mmc_phase_data *data; 105 spinlock_t *lock; 106 }; 107 108 #define to_mmc_phase(_hw) container_of(_hw, struct mmc_phase, hw) 109 110 static int mmc_get_phase(struct clk_hw *hw) 111 { 112 struct clk *mmc, *mmc_parent, *clk = hw->clk; 113 struct mmc_phase *phase = to_mmc_phase(hw); 114 unsigned int mmc_rate, mmc_parent_rate; 115 u16 step, mmc_div; 116 u32 value; 117 u8 delay; 118 119 value = readl(phase->reg); 120 delay = (value >> phase->data->offset) & 0x3; 121 122 if (!delay) 123 return 180; 124 125 /* Get the main MMC clock */ 126 mmc = clk_get_parent(clk); 127 if (!mmc) 128 return -EINVAL; 129 130 /* And its rate */ 131 mmc_rate = clk_get_rate(mmc); 132 if (!mmc_rate) 133 return -EINVAL; 134 135 /* Now, get the MMC parent (most likely some PLL) */ 136 mmc_parent = clk_get_parent(mmc); 137 if (!mmc_parent) 138 return -EINVAL; 139 140 /* And its rate */ 141 mmc_parent_rate = clk_get_rate(mmc_parent); 142 if (!mmc_parent_rate) 143 return -EINVAL; 144 145 /* Get MMC clock divider */ 146 mmc_div = mmc_parent_rate / mmc_rate; 147 148 step = DIV_ROUND_CLOSEST(360, mmc_div); 149 return delay * step; 150 } 151 152 static int mmc_set_phase(struct clk_hw *hw, int degrees) 153 { 154 struct clk *mmc, *mmc_parent, *clk = hw->clk; 155 struct mmc_phase *phase = to_mmc_phase(hw); 156 unsigned int mmc_rate, mmc_parent_rate; 157 unsigned long flags; 158 u32 value; 159 u8 delay; 160 161 /* Get the main MMC clock */ 162 mmc = clk_get_parent(clk); 163 if (!mmc) 164 return -EINVAL; 165 166 /* And its rate */ 167 mmc_rate = clk_get_rate(mmc); 168 if (!mmc_rate) 169 return -EINVAL; 170 171 /* Now, get the MMC parent (most likely some PLL) */ 172 mmc_parent = clk_get_parent(mmc); 173 if (!mmc_parent) 174 return -EINVAL; 175 176 /* And its rate */ 177 mmc_parent_rate = clk_get_rate(mmc_parent); 178 if (!mmc_parent_rate) 179 return -EINVAL; 180 181 if (degrees != 180) { 182 u16 step, mmc_div; 183 184 /* Get MMC clock divider */ 185 mmc_div = mmc_parent_rate / mmc_rate; 186 187 /* 188 * We can only outphase the clocks by multiple of the 189 * PLL's period. 190 * 191 * Since the MMC clock in only a divider, and the 192 * formula to get the outphasing in degrees is deg = 193 * 360 * delta / period 194 * 195 * If we simplify this formula, we can see that the 196 * only thing that we're concerned about is the number 197 * of period we want to outphase our clock from, and 198 * the divider set by the MMC clock. 199 */ 200 step = DIV_ROUND_CLOSEST(360, mmc_div); 201 delay = DIV_ROUND_CLOSEST(degrees, step); 202 } else { 203 delay = 0; 204 } 205 206 spin_lock_irqsave(phase->lock, flags); 207 value = readl(phase->reg); 208 value &= ~GENMASK(phase->data->offset + 3, phase->data->offset); 209 value |= delay << phase->data->offset; 210 writel(value, phase->reg); 211 spin_unlock_irqrestore(phase->lock, flags); 212 213 return 0; 214 } 215 216 static const struct clk_ops mmc_clk_ops = { 217 .get_phase = mmc_get_phase, 218 .set_phase = mmc_set_phase, 219 }; 220 221 static void __init sun4i_a10_mmc_phase_setup(struct device_node *node, 222 struct mmc_phase_data *data) 223 { 224 const char *parent_names[1] = { of_clk_get_parent_name(node, 0) }; 225 struct clk_init_data init = { 226 .num_parents = 1, 227 .parent_names = parent_names, 228 .ops = &mmc_clk_ops, 229 }; 230 231 struct mmc_phase *phase; 232 struct clk *clk; 233 234 phase = kmalloc(sizeof(*phase), GFP_KERNEL); 235 if (!phase) 236 return; 237 238 phase->hw.init = &init; 239 240 phase->reg = of_iomap(node, 0); 241 if (!phase->reg) 242 goto err_free; 243 244 phase->data = data; 245 phase->lock = &sun4i_a10_mod0_lock; 246 247 if (of_property_read_string(node, "clock-output-names", &init.name)) 248 init.name = node->name; 249 250 clk = clk_register(NULL, &phase->hw); 251 if (IS_ERR(clk)) 252 goto err_unmap; 253 254 of_clk_add_provider(node, of_clk_src_simple_get, clk); 255 256 return; 257 258 err_unmap: 259 iounmap(phase->reg); 260 err_free: 261 kfree(phase); 262 } 263 264 265 static struct mmc_phase_data mmc_output_clk = { 266 .offset = 8, 267 }; 268 269 static struct mmc_phase_data mmc_sample_clk = { 270 .offset = 20, 271 }; 272 273 static void __init sun4i_a10_mmc_output_setup(struct device_node *node) 274 { 275 sun4i_a10_mmc_phase_setup(node, &mmc_output_clk); 276 } 277 CLK_OF_DECLARE(sun4i_a10_mmc_output, "allwinner,sun4i-a10-mmc-output-clk", sun4i_a10_mmc_output_setup); 278 279 static void __init sun4i_a10_mmc_sample_setup(struct device_node *node) 280 { 281 sun4i_a10_mmc_phase_setup(node, &mmc_sample_clk); 282 } 283 CLK_OF_DECLARE(sun4i_a10_mmc_sample, "allwinner,sun4i-a10-mmc-sample-clk", sun4i_a10_mmc_sample_setup); 284