1 /* 2 * WM831x clock control 3 * 4 * Copyright 2011-2 Wolfson Microelectronics PLC. 5 * 6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 * 13 */ 14 15 #include <linux/clk.h> 16 #include <linux/clk-provider.h> 17 #include <linux/delay.h> 18 #include <linux/module.h> 19 #include <linux/slab.h> 20 #include <linux/platform_device.h> 21 #include <linux/mfd/wm831x/core.h> 22 23 struct wm831x_clk { 24 struct wm831x *wm831x; 25 struct clk_hw xtal_hw; 26 struct clk_hw fll_hw; 27 struct clk_hw clkout_hw; 28 struct clk *xtal; 29 struct clk *fll; 30 struct clk *clkout; 31 bool xtal_ena; 32 }; 33 34 static int wm831x_xtal_is_prepared(struct clk_hw *hw) 35 { 36 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 37 xtal_hw); 38 39 return clkdata->xtal_ena; 40 } 41 42 static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw, 43 unsigned long parent_rate) 44 { 45 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 46 xtal_hw); 47 48 if (clkdata->xtal_ena) 49 return 32768; 50 else 51 return 0; 52 } 53 54 static const struct clk_ops wm831x_xtal_ops = { 55 .is_prepared = wm831x_xtal_is_prepared, 56 .recalc_rate = wm831x_xtal_recalc_rate, 57 }; 58 59 static struct clk_init_data wm831x_xtal_init = { 60 .name = "xtal", 61 .ops = &wm831x_xtal_ops, 62 .flags = CLK_IS_ROOT, 63 }; 64 65 static const unsigned long wm831x_fll_auto_rates[] = { 66 2048000, 67 11289600, 68 12000000, 69 12288000, 70 19200000, 71 22579600, 72 24000000, 73 24576000, 74 }; 75 76 static int wm831x_fll_is_prepared(struct clk_hw *hw) 77 { 78 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 79 fll_hw); 80 struct wm831x *wm831x = clkdata->wm831x; 81 int ret; 82 83 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1); 84 if (ret < 0) { 85 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n", 86 ret); 87 return true; 88 } 89 90 return (ret & WM831X_FLL_ENA) != 0; 91 } 92 93 static int wm831x_fll_prepare(struct clk_hw *hw) 94 { 95 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 96 fll_hw); 97 struct wm831x *wm831x = clkdata->wm831x; 98 int ret; 99 100 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1, 101 WM831X_FLL_ENA, WM831X_FLL_ENA); 102 if (ret != 0) 103 dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret); 104 105 usleep_range(2000, 2000); 106 107 return ret; 108 } 109 110 static void wm831x_fll_unprepare(struct clk_hw *hw) 111 { 112 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 113 fll_hw); 114 struct wm831x *wm831x = clkdata->wm831x; 115 int ret; 116 117 ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1, WM831X_FLL_ENA, 0); 118 if (ret != 0) 119 dev_crit(wm831x->dev, "Failed to disable FLL: %d\n", ret); 120 } 121 122 static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw, 123 unsigned long parent_rate) 124 { 125 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 126 fll_hw); 127 struct wm831x *wm831x = clkdata->wm831x; 128 int ret; 129 130 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2); 131 if (ret < 0) { 132 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n", 133 ret); 134 return 0; 135 } 136 137 if (ret & WM831X_FLL_AUTO) 138 return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK]; 139 140 dev_err(wm831x->dev, "FLL only supported in AUTO mode\n"); 141 142 return 0; 143 } 144 145 static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate, 146 unsigned long *unused) 147 { 148 int best = 0; 149 int i; 150 151 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++) 152 if (abs(wm831x_fll_auto_rates[i] - rate) < 153 abs(wm831x_fll_auto_rates[best] - rate)) 154 best = i; 155 156 return wm831x_fll_auto_rates[best]; 157 } 158 159 static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate, 160 unsigned long parent_rate) 161 { 162 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 163 fll_hw); 164 struct wm831x *wm831x = clkdata->wm831x; 165 int i; 166 167 for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++) 168 if (wm831x_fll_auto_rates[i] == rate) 169 break; 170 if (i == ARRAY_SIZE(wm831x_fll_auto_rates)) 171 return -EINVAL; 172 173 if (wm831x_fll_is_prepared(hw)) 174 return -EPERM; 175 176 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2, 177 WM831X_FLL_AUTO_FREQ_MASK, i); 178 } 179 180 static const char *wm831x_fll_parents[] = { 181 "xtal", 182 "clkin", 183 }; 184 185 static u8 wm831x_fll_get_parent(struct clk_hw *hw) 186 { 187 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 188 fll_hw); 189 struct wm831x *wm831x = clkdata->wm831x; 190 int ret; 191 192 /* AUTO mode is always clocked from the crystal */ 193 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2); 194 if (ret < 0) { 195 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n", 196 ret); 197 return 0; 198 } 199 200 if (ret & WM831X_FLL_AUTO) 201 return 0; 202 203 ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5); 204 if (ret < 0) { 205 dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n", 206 ret); 207 return 0; 208 } 209 210 switch (ret & WM831X_FLL_CLK_SRC_MASK) { 211 case 0: 212 return 0; 213 case 1: 214 return 1; 215 default: 216 dev_err(wm831x->dev, "Unsupported FLL clock source %d\n", 217 ret & WM831X_FLL_CLK_SRC_MASK); 218 return 0; 219 } 220 } 221 222 static const struct clk_ops wm831x_fll_ops = { 223 .is_prepared = wm831x_fll_is_prepared, 224 .prepare = wm831x_fll_prepare, 225 .unprepare = wm831x_fll_unprepare, 226 .round_rate = wm831x_fll_round_rate, 227 .recalc_rate = wm831x_fll_recalc_rate, 228 .set_rate = wm831x_fll_set_rate, 229 .get_parent = wm831x_fll_get_parent, 230 }; 231 232 static struct clk_init_data wm831x_fll_init = { 233 .name = "fll", 234 .ops = &wm831x_fll_ops, 235 .parent_names = wm831x_fll_parents, 236 .num_parents = ARRAY_SIZE(wm831x_fll_parents), 237 .flags = CLK_SET_RATE_GATE, 238 }; 239 240 static int wm831x_clkout_is_prepared(struct clk_hw *hw) 241 { 242 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 243 clkout_hw); 244 struct wm831x *wm831x = clkdata->wm831x; 245 int ret; 246 247 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1); 248 if (ret < 0) { 249 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n", 250 ret); 251 return true; 252 } 253 254 return (ret & WM831X_CLKOUT_ENA) != 0; 255 } 256 257 static int wm831x_clkout_prepare(struct clk_hw *hw) 258 { 259 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 260 clkout_hw); 261 struct wm831x *wm831x = clkdata->wm831x; 262 int ret; 263 264 ret = wm831x_reg_unlock(wm831x); 265 if (ret != 0) { 266 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret); 267 return ret; 268 } 269 270 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1, 271 WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA); 272 if (ret != 0) 273 dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret); 274 275 wm831x_reg_lock(wm831x); 276 277 return ret; 278 } 279 280 static void wm831x_clkout_unprepare(struct clk_hw *hw) 281 { 282 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 283 clkout_hw); 284 struct wm831x *wm831x = clkdata->wm831x; 285 int ret; 286 287 ret = wm831x_reg_unlock(wm831x); 288 if (ret != 0) { 289 dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret); 290 return; 291 } 292 293 ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1, 294 WM831X_CLKOUT_ENA, 0); 295 if (ret != 0) 296 dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret); 297 298 wm831x_reg_lock(wm831x); 299 } 300 301 static const char *wm831x_clkout_parents[] = { 302 "fll", 303 "xtal", 304 }; 305 306 static u8 wm831x_clkout_get_parent(struct clk_hw *hw) 307 { 308 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 309 clkout_hw); 310 struct wm831x *wm831x = clkdata->wm831x; 311 int ret; 312 313 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1); 314 if (ret < 0) { 315 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n", 316 ret); 317 return 0; 318 } 319 320 if (ret & WM831X_CLKOUT_SRC) 321 return 1; 322 else 323 return 0; 324 } 325 326 static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent) 327 { 328 struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, 329 clkout_hw); 330 struct wm831x *wm831x = clkdata->wm831x; 331 332 return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1, 333 WM831X_CLKOUT_SRC, 334 parent << WM831X_CLKOUT_SRC_SHIFT); 335 } 336 337 static const struct clk_ops wm831x_clkout_ops = { 338 .is_prepared = wm831x_clkout_is_prepared, 339 .prepare = wm831x_clkout_prepare, 340 .unprepare = wm831x_clkout_unprepare, 341 .get_parent = wm831x_clkout_get_parent, 342 .set_parent = wm831x_clkout_set_parent, 343 }; 344 345 static struct clk_init_data wm831x_clkout_init = { 346 .name = "clkout", 347 .ops = &wm831x_clkout_ops, 348 .parent_names = wm831x_clkout_parents, 349 .num_parents = ARRAY_SIZE(wm831x_clkout_parents), 350 .flags = CLK_SET_RATE_PARENT, 351 }; 352 353 static int wm831x_clk_probe(struct platform_device *pdev) 354 { 355 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 356 struct wm831x_clk *clkdata; 357 int ret; 358 359 clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL); 360 if (!clkdata) 361 return -ENOMEM; 362 363 clkdata->wm831x = wm831x; 364 365 /* XTAL_ENA can only be set via OTP/InstantConfig so just read once */ 366 ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2); 367 if (ret < 0) { 368 dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n", 369 ret); 370 return ret; 371 } 372 clkdata->xtal_ena = ret & WM831X_XTAL_ENA; 373 374 clkdata->xtal_hw.init = &wm831x_xtal_init; 375 clkdata->xtal = devm_clk_register(&pdev->dev, &clkdata->xtal_hw); 376 if (IS_ERR(clkdata->xtal)) 377 return PTR_ERR(clkdata->xtal); 378 379 clkdata->fll_hw.init = &wm831x_fll_init; 380 clkdata->fll = devm_clk_register(&pdev->dev, &clkdata->fll_hw); 381 if (IS_ERR(clkdata->fll)) 382 return PTR_ERR(clkdata->fll); 383 384 clkdata->clkout_hw.init = &wm831x_clkout_init; 385 clkdata->clkout = devm_clk_register(&pdev->dev, &clkdata->clkout_hw); 386 if (IS_ERR(clkdata->clkout)) 387 return PTR_ERR(clkdata->clkout); 388 389 platform_set_drvdata(pdev, clkdata); 390 391 return 0; 392 } 393 394 static struct platform_driver wm831x_clk_driver = { 395 .probe = wm831x_clk_probe, 396 .driver = { 397 .name = "wm831x-clk", 398 }, 399 }; 400 401 module_platform_driver(wm831x_clk_driver); 402 403 /* Module information */ 404 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 405 MODULE_DESCRIPTION("WM831x clock driver"); 406 MODULE_LICENSE("GPL"); 407 MODULE_ALIAS("platform:wm831x-clk"); 408