1 /* 2 * ACPI support for Intel Lynxpoint LPSS. 3 * 4 * Copyright (C) 2013, Intel Corporation 5 * Authors: Mika Westerberg <mika.westerberg@linux.intel.com> 6 * Rafael J. Wysocki <rafael.j.wysocki@intel.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/acpi.h> 14 #include <linux/clk.h> 15 #include <linux/clkdev.h> 16 #include <linux/clk-provider.h> 17 #include <linux/err.h> 18 #include <linux/io.h> 19 #include <linux/platform_device.h> 20 #include <linux/platform_data/clk-lpss.h> 21 #include <linux/pm_runtime.h> 22 23 #include "internal.h" 24 25 ACPI_MODULE_NAME("acpi_lpss"); 26 27 #define LPSS_CLK_SIZE 0x04 28 #define LPSS_LTR_SIZE 0x18 29 30 /* Offsets relative to LPSS_PRIVATE_OFFSET */ 31 #define LPSS_GENERAL 0x08 32 #define LPSS_GENERAL_LTR_MODE_SW BIT(2) 33 #define LPSS_SW_LTR 0x10 34 #define LPSS_AUTO_LTR 0x14 35 #define LPSS_TX_INT 0x20 36 #define LPSS_TX_INT_MASK BIT(1) 37 38 struct lpss_shared_clock { 39 const char *name; 40 unsigned long rate; 41 struct clk *clk; 42 }; 43 44 struct lpss_private_data; 45 46 struct lpss_device_desc { 47 bool clk_required; 48 const char *clkdev_name; 49 bool ltr_required; 50 unsigned int prv_offset; 51 size_t prv_size_override; 52 bool clk_gate; 53 struct lpss_shared_clock *shared_clock; 54 void (*setup)(struct lpss_private_data *pdata); 55 }; 56 57 static struct lpss_device_desc lpss_dma_desc = { 58 .clk_required = true, 59 .clkdev_name = "hclk", 60 }; 61 62 struct lpss_private_data { 63 void __iomem *mmio_base; 64 resource_size_t mmio_size; 65 struct clk *clk; 66 const struct lpss_device_desc *dev_desc; 67 }; 68 69 static void lpss_uart_setup(struct lpss_private_data *pdata) 70 { 71 unsigned int tx_int_offset = pdata->dev_desc->prv_offset + LPSS_TX_INT; 72 u32 reg; 73 74 reg = readl(pdata->mmio_base + tx_int_offset); 75 writel(reg | LPSS_TX_INT_MASK, pdata->mmio_base + tx_int_offset); 76 } 77 78 static struct lpss_device_desc lpt_dev_desc = { 79 .clk_required = true, 80 .prv_offset = 0x800, 81 .ltr_required = true, 82 .clk_gate = true, 83 }; 84 85 static struct lpss_device_desc lpt_uart_dev_desc = { 86 .clk_required = true, 87 .prv_offset = 0x800, 88 .ltr_required = true, 89 .clk_gate = true, 90 .setup = lpss_uart_setup, 91 }; 92 93 static struct lpss_device_desc lpt_sdio_dev_desc = { 94 .prv_offset = 0x1000, 95 .prv_size_override = 0x1018, 96 .ltr_required = true, 97 }; 98 99 static struct lpss_shared_clock uart_clock = { 100 .name = "uart_clk", 101 .rate = 44236800, 102 }; 103 104 static struct lpss_device_desc byt_uart_dev_desc = { 105 .clk_required = true, 106 .prv_offset = 0x800, 107 .clk_gate = true, 108 .shared_clock = &uart_clock, 109 .setup = lpss_uart_setup, 110 }; 111 112 static struct lpss_shared_clock spi_clock = { 113 .name = "spi_clk", 114 .rate = 50000000, 115 }; 116 117 static struct lpss_device_desc byt_spi_dev_desc = { 118 .clk_required = true, 119 .prv_offset = 0x400, 120 .clk_gate = true, 121 .shared_clock = &spi_clock, 122 }; 123 124 static struct lpss_device_desc byt_sdio_dev_desc = { 125 .clk_required = true, 126 }; 127 128 static struct lpss_shared_clock i2c_clock = { 129 .name = "i2c_clk", 130 .rate = 100000000, 131 }; 132 133 static struct lpss_device_desc byt_i2c_dev_desc = { 134 .clk_required = true, 135 .prv_offset = 0x800, 136 .shared_clock = &i2c_clock, 137 }; 138 139 static const struct acpi_device_id acpi_lpss_device_ids[] = { 140 /* Generic LPSS devices */ 141 { "INTL9C60", (unsigned long)&lpss_dma_desc }, 142 143 /* Lynxpoint LPSS devices */ 144 { "INT33C0", (unsigned long)&lpt_dev_desc }, 145 { "INT33C1", (unsigned long)&lpt_dev_desc }, 146 { "INT33C2", (unsigned long)&lpt_dev_desc }, 147 { "INT33C3", (unsigned long)&lpt_dev_desc }, 148 { "INT33C4", (unsigned long)&lpt_uart_dev_desc }, 149 { "INT33C5", (unsigned long)&lpt_uart_dev_desc }, 150 { "INT33C6", (unsigned long)&lpt_sdio_dev_desc }, 151 { "INT33C7", }, 152 153 /* BayTrail LPSS devices */ 154 { "80860F0A", (unsigned long)&byt_uart_dev_desc }, 155 { "80860F0E", (unsigned long)&byt_spi_dev_desc }, 156 { "80860F14", (unsigned long)&byt_sdio_dev_desc }, 157 { "80860F41", (unsigned long)&byt_i2c_dev_desc }, 158 { "INT33B2", }, 159 160 { } 161 }; 162 163 static int is_memory(struct acpi_resource *res, void *not_used) 164 { 165 struct resource r; 166 return !acpi_dev_resource_memory(res, &r); 167 } 168 169 /* LPSS main clock device. */ 170 static struct platform_device *lpss_clk_dev; 171 172 static inline void lpt_register_clock_device(void) 173 { 174 lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0); 175 } 176 177 static int register_device_clock(struct acpi_device *adev, 178 struct lpss_private_data *pdata) 179 { 180 const struct lpss_device_desc *dev_desc = pdata->dev_desc; 181 struct lpss_shared_clock *shared_clock = dev_desc->shared_clock; 182 struct clk *clk = ERR_PTR(-ENODEV); 183 struct lpss_clk_data *clk_data; 184 const char *parent; 185 186 if (!lpss_clk_dev) 187 lpt_register_clock_device(); 188 189 clk_data = platform_get_drvdata(lpss_clk_dev); 190 if (!clk_data) 191 return -ENODEV; 192 193 if (dev_desc->clkdev_name) { 194 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name, 195 dev_name(&adev->dev)); 196 return 0; 197 } 198 199 if (!pdata->mmio_base 200 || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE) 201 return -ENODATA; 202 203 parent = clk_data->name; 204 205 if (shared_clock) { 206 clk = shared_clock->clk; 207 if (!clk) { 208 clk = clk_register_fixed_rate(NULL, shared_clock->name, 209 "lpss_clk", 0, 210 shared_clock->rate); 211 shared_clock->clk = clk; 212 } 213 parent = shared_clock->name; 214 } 215 216 if (dev_desc->clk_gate) { 217 clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0, 218 pdata->mmio_base + dev_desc->prv_offset, 219 0, 0, NULL); 220 pdata->clk = clk; 221 } 222 223 if (IS_ERR(clk)) 224 return PTR_ERR(clk); 225 226 clk_register_clkdev(clk, NULL, dev_name(&adev->dev)); 227 return 0; 228 } 229 230 static int acpi_lpss_create_device(struct acpi_device *adev, 231 const struct acpi_device_id *id) 232 { 233 struct lpss_device_desc *dev_desc; 234 struct lpss_private_data *pdata; 235 struct resource_list_entry *rentry; 236 struct list_head resource_list; 237 int ret; 238 239 dev_desc = (struct lpss_device_desc *)id->driver_data; 240 if (!dev_desc) 241 return acpi_create_platform_device(adev, id); 242 243 pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); 244 if (!pdata) 245 return -ENOMEM; 246 247 INIT_LIST_HEAD(&resource_list); 248 ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL); 249 if (ret < 0) 250 goto err_out; 251 252 list_for_each_entry(rentry, &resource_list, node) 253 if (resource_type(&rentry->res) == IORESOURCE_MEM) { 254 if (dev_desc->prv_size_override) 255 pdata->mmio_size = dev_desc->prv_size_override; 256 else 257 pdata->mmio_size = resource_size(&rentry->res); 258 pdata->mmio_base = ioremap(rentry->res.start, 259 pdata->mmio_size); 260 pdata->dev_desc = dev_desc; 261 break; 262 } 263 264 acpi_dev_free_resource_list(&resource_list); 265 266 if (dev_desc->clk_required) { 267 ret = register_device_clock(adev, pdata); 268 if (ret) { 269 /* Skip the device, but continue the namespace scan. */ 270 ret = 0; 271 goto err_out; 272 } 273 } 274 275 /* 276 * This works around a known issue in ACPI tables where LPSS devices 277 * have _PS0 and _PS3 without _PSC (and no power resources), so 278 * acpi_bus_init_power() will assume that the BIOS has put them into D0. 279 */ 280 ret = acpi_device_fix_up_power(adev); 281 if (ret) { 282 /* Skip the device, but continue the namespace scan. */ 283 ret = 0; 284 goto err_out; 285 } 286 287 if (dev_desc->setup) 288 dev_desc->setup(pdata); 289 290 adev->driver_data = pdata; 291 ret = acpi_create_platform_device(adev, id); 292 if (ret > 0) 293 return ret; 294 295 adev->driver_data = NULL; 296 297 err_out: 298 kfree(pdata); 299 return ret; 300 } 301 302 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val) 303 { 304 struct acpi_device *adev; 305 struct lpss_private_data *pdata; 306 unsigned long flags; 307 int ret; 308 309 ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev); 310 if (WARN_ON(ret)) 311 return ret; 312 313 spin_lock_irqsave(&dev->power.lock, flags); 314 if (pm_runtime_suspended(dev)) { 315 ret = -EAGAIN; 316 goto out; 317 } 318 pdata = acpi_driver_data(adev); 319 if (WARN_ON(!pdata || !pdata->mmio_base)) { 320 ret = -ENODEV; 321 goto out; 322 } 323 *val = readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg); 324 325 out: 326 spin_unlock_irqrestore(&dev->power.lock, flags); 327 return ret; 328 } 329 330 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr, 331 char *buf) 332 { 333 u32 ltr_value = 0; 334 unsigned int reg; 335 int ret; 336 337 reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR; 338 ret = lpss_reg_read(dev, reg, <r_value); 339 if (ret) 340 return ret; 341 342 return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value); 343 } 344 345 static ssize_t lpss_ltr_mode_show(struct device *dev, 346 struct device_attribute *attr, char *buf) 347 { 348 u32 ltr_mode = 0; 349 char *outstr; 350 int ret; 351 352 ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode); 353 if (ret) 354 return ret; 355 356 outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto"; 357 return sprintf(buf, "%s\n", outstr); 358 } 359 360 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL); 361 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL); 362 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL); 363 364 static struct attribute *lpss_attrs[] = { 365 &dev_attr_auto_ltr.attr, 366 &dev_attr_sw_ltr.attr, 367 &dev_attr_ltr_mode.attr, 368 NULL, 369 }; 370 371 static struct attribute_group lpss_attr_group = { 372 .attrs = lpss_attrs, 373 .name = "lpss_ltr", 374 }; 375 376 static int acpi_lpss_platform_notify(struct notifier_block *nb, 377 unsigned long action, void *data) 378 { 379 struct platform_device *pdev = to_platform_device(data); 380 struct lpss_private_data *pdata; 381 struct acpi_device *adev; 382 const struct acpi_device_id *id; 383 int ret = 0; 384 385 id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev); 386 if (!id || !id->driver_data) 387 return 0; 388 389 if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev)) 390 return 0; 391 392 pdata = acpi_driver_data(adev); 393 if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required) 394 return 0; 395 396 if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) { 397 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n"); 398 return 0; 399 } 400 401 if (action == BUS_NOTIFY_ADD_DEVICE) 402 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group); 403 else if (action == BUS_NOTIFY_DEL_DEVICE) 404 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group); 405 406 return ret; 407 } 408 409 static struct notifier_block acpi_lpss_nb = { 410 .notifier_call = acpi_lpss_platform_notify, 411 }; 412 413 static struct acpi_scan_handler lpss_handler = { 414 .ids = acpi_lpss_device_ids, 415 .attach = acpi_lpss_create_device, 416 }; 417 418 void __init acpi_lpss_init(void) 419 { 420 if (!lpt_clk_init()) { 421 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb); 422 acpi_scan_add_handler(&lpss_handler); 423 } 424 } 425