1 /* 2 * drivers/mfd/mfd-core.c 3 * 4 * core MFD support 5 * Copyright (c) 2006 Ian Molton 6 * Copyright (c) 2007,2008 Dmitry Baryshkov 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 14 #include <linux/kernel.h> 15 #include <linux/platform_device.h> 16 #include <linux/acpi.h> 17 #include <linux/mfd/core.h> 18 #include <linux/pm_runtime.h> 19 #include <linux/slab.h> 20 #include <linux/module.h> 21 #include <linux/irqdomain.h> 22 #include <linux/of.h> 23 #include <linux/regulator/consumer.h> 24 25 static struct device_type mfd_dev_type = { 26 .name = "mfd_device", 27 }; 28 29 int mfd_cell_enable(struct platform_device *pdev) 30 { 31 const struct mfd_cell *cell = mfd_get_cell(pdev); 32 int err = 0; 33 34 /* only call enable hook if the cell wasn't previously enabled */ 35 if (atomic_inc_return(cell->usage_count) == 1) 36 err = cell->enable(pdev); 37 38 /* if the enable hook failed, decrement counter to allow retries */ 39 if (err) 40 atomic_dec(cell->usage_count); 41 42 return err; 43 } 44 EXPORT_SYMBOL(mfd_cell_enable); 45 46 int mfd_cell_disable(struct platform_device *pdev) 47 { 48 const struct mfd_cell *cell = mfd_get_cell(pdev); 49 int err = 0; 50 51 /* only disable if no other clients are using it */ 52 if (atomic_dec_return(cell->usage_count) == 0) 53 err = cell->disable(pdev); 54 55 /* if the disable hook failed, increment to allow retries */ 56 if (err) 57 atomic_inc(cell->usage_count); 58 59 /* sanity check; did someone call disable too many times? */ 60 WARN_ON(atomic_read(cell->usage_count) < 0); 61 62 return err; 63 } 64 EXPORT_SYMBOL(mfd_cell_disable); 65 66 static int mfd_platform_add_cell(struct platform_device *pdev, 67 const struct mfd_cell *cell, 68 atomic_t *usage_count) 69 { 70 if (!cell) 71 return 0; 72 73 pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL); 74 if (!pdev->mfd_cell) 75 return -ENOMEM; 76 77 pdev->mfd_cell->usage_count = usage_count; 78 return 0; 79 } 80 81 #if IS_ENABLED(CONFIG_ACPI) 82 static void mfd_acpi_add_device(const struct mfd_cell *cell, 83 struct platform_device *pdev) 84 { 85 const struct mfd_cell_acpi_match *match = cell->acpi_match; 86 struct acpi_device *parent, *child; 87 struct acpi_device *adev; 88 89 parent = ACPI_COMPANION(pdev->dev.parent); 90 if (!parent) 91 return; 92 93 /* 94 * MFD child device gets its ACPI handle either from the ACPI device 95 * directly under the parent that matches the either _HID or _CID, or 96 * _ADR or it will use the parent handle if is no ID is given. 97 * 98 * Note that use of _ADR is a grey area in the ACPI specification, 99 * though Intel Galileo Gen2 is using it to distinguish the children 100 * devices. 101 */ 102 adev = parent; 103 if (match) { 104 if (match->pnpid) { 105 struct acpi_device_id ids[2] = {}; 106 107 strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id)); 108 list_for_each_entry(child, &parent->children, node) { 109 if (acpi_match_device_ids(child, ids)) { 110 adev = child; 111 break; 112 } 113 } 114 } else { 115 unsigned long long adr; 116 acpi_status status; 117 118 list_for_each_entry(child, &parent->children, node) { 119 status = acpi_evaluate_integer(child->handle, 120 "_ADR", NULL, 121 &adr); 122 if (ACPI_SUCCESS(status) && match->adr == adr) { 123 adev = child; 124 break; 125 } 126 } 127 } 128 } 129 130 ACPI_COMPANION_SET(&pdev->dev, adev); 131 } 132 #else 133 static inline void mfd_acpi_add_device(const struct mfd_cell *cell, 134 struct platform_device *pdev) 135 { 136 } 137 #endif 138 139 static int mfd_add_device(struct device *parent, int id, 140 const struct mfd_cell *cell, atomic_t *usage_count, 141 struct resource *mem_base, 142 int irq_base, struct irq_domain *domain) 143 { 144 struct resource *res; 145 struct platform_device *pdev; 146 struct device_node *np = NULL; 147 int ret = -ENOMEM; 148 int platform_id; 149 int r; 150 151 if (id == PLATFORM_DEVID_AUTO) 152 platform_id = id; 153 else 154 platform_id = id + cell->id; 155 156 pdev = platform_device_alloc(cell->name, platform_id); 157 if (!pdev) 158 goto fail_alloc; 159 160 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL); 161 if (!res) 162 goto fail_device; 163 164 pdev->dev.parent = parent; 165 pdev->dev.type = &mfd_dev_type; 166 pdev->dev.dma_mask = parent->dma_mask; 167 pdev->dev.dma_parms = parent->dma_parms; 168 pdev->dev.coherent_dma_mask = parent->coherent_dma_mask; 169 170 ret = regulator_bulk_register_supply_alias( 171 &pdev->dev, cell->parent_supplies, 172 parent, cell->parent_supplies, 173 cell->num_parent_supplies); 174 if (ret < 0) 175 goto fail_res; 176 177 if (parent->of_node && cell->of_compatible) { 178 for_each_child_of_node(parent->of_node, np) { 179 if (of_device_is_compatible(np, cell->of_compatible)) { 180 pdev->dev.of_node = np; 181 break; 182 } 183 } 184 } 185 186 mfd_acpi_add_device(cell, pdev); 187 188 if (cell->pdata_size) { 189 ret = platform_device_add_data(pdev, 190 cell->platform_data, cell->pdata_size); 191 if (ret) 192 goto fail_alias; 193 } 194 195 ret = mfd_platform_add_cell(pdev, cell, usage_count); 196 if (ret) 197 goto fail_alias; 198 199 for (r = 0; r < cell->num_resources; r++) { 200 res[r].name = cell->resources[r].name; 201 res[r].flags = cell->resources[r].flags; 202 203 /* Find out base to use */ 204 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) { 205 res[r].parent = mem_base; 206 res[r].start = mem_base->start + 207 cell->resources[r].start; 208 res[r].end = mem_base->start + 209 cell->resources[r].end; 210 } else if (cell->resources[r].flags & IORESOURCE_IRQ) { 211 if (domain) { 212 /* Unable to create mappings for IRQ ranges. */ 213 WARN_ON(cell->resources[r].start != 214 cell->resources[r].end); 215 res[r].start = res[r].end = irq_create_mapping( 216 domain, cell->resources[r].start); 217 } else { 218 res[r].start = irq_base + 219 cell->resources[r].start; 220 res[r].end = irq_base + 221 cell->resources[r].end; 222 } 223 } else { 224 res[r].parent = cell->resources[r].parent; 225 res[r].start = cell->resources[r].start; 226 res[r].end = cell->resources[r].end; 227 } 228 229 if (!cell->ignore_resource_conflicts) { 230 if (has_acpi_companion(&pdev->dev)) { 231 ret = acpi_check_resource_conflict(&res[r]); 232 if (ret) 233 goto fail_alias; 234 } 235 } 236 } 237 238 ret = platform_device_add_resources(pdev, res, cell->num_resources); 239 if (ret) 240 goto fail_alias; 241 242 ret = platform_device_add(pdev); 243 if (ret) 244 goto fail_alias; 245 246 if (cell->pm_runtime_no_callbacks) 247 pm_runtime_no_callbacks(&pdev->dev); 248 249 kfree(res); 250 251 return 0; 252 253 fail_alias: 254 regulator_bulk_unregister_supply_alias(&pdev->dev, 255 cell->parent_supplies, 256 cell->num_parent_supplies); 257 fail_res: 258 kfree(res); 259 fail_device: 260 platform_device_put(pdev); 261 fail_alloc: 262 return ret; 263 } 264 265 int mfd_add_devices(struct device *parent, int id, 266 const struct mfd_cell *cells, int n_devs, 267 struct resource *mem_base, 268 int irq_base, struct irq_domain *domain) 269 { 270 int i; 271 int ret; 272 atomic_t *cnts; 273 274 /* initialize reference counting for all cells */ 275 cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL); 276 if (!cnts) 277 return -ENOMEM; 278 279 for (i = 0; i < n_devs; i++) { 280 atomic_set(&cnts[i], 0); 281 ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base, 282 irq_base, domain); 283 if (ret) 284 goto fail; 285 } 286 287 return 0; 288 289 fail: 290 if (i) 291 mfd_remove_devices(parent); 292 else 293 kfree(cnts); 294 return ret; 295 } 296 EXPORT_SYMBOL(mfd_add_devices); 297 298 static int mfd_remove_devices_fn(struct device *dev, void *c) 299 { 300 struct platform_device *pdev; 301 const struct mfd_cell *cell; 302 atomic_t **usage_count = c; 303 304 if (dev->type != &mfd_dev_type) 305 return 0; 306 307 pdev = to_platform_device(dev); 308 cell = mfd_get_cell(pdev); 309 310 regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies, 311 cell->num_parent_supplies); 312 313 /* find the base address of usage_count pointers (for freeing) */ 314 if (!*usage_count || (cell->usage_count < *usage_count)) 315 *usage_count = cell->usage_count; 316 317 platform_device_unregister(pdev); 318 return 0; 319 } 320 321 void mfd_remove_devices(struct device *parent) 322 { 323 atomic_t *cnts = NULL; 324 325 device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn); 326 kfree(cnts); 327 } 328 EXPORT_SYMBOL(mfd_remove_devices); 329 330 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones) 331 { 332 struct mfd_cell cell_entry; 333 struct device *dev; 334 struct platform_device *pdev; 335 int i; 336 337 /* fetch the parent cell's device (should already be registered!) */ 338 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell); 339 if (!dev) { 340 printk(KERN_ERR "failed to find device for cell %s\n", cell); 341 return -ENODEV; 342 } 343 pdev = to_platform_device(dev); 344 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry)); 345 346 WARN_ON(!cell_entry.enable); 347 348 for (i = 0; i < n_clones; i++) { 349 cell_entry.name = clones[i]; 350 /* don't give up if a single call fails; just report error */ 351 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, 352 cell_entry.usage_count, NULL, 0, NULL)) 353 dev_err(dev, "failed to create platform device '%s'\n", 354 clones[i]); 355 } 356 357 return 0; 358 } 359 EXPORT_SYMBOL(mfd_clone_cell); 360 361 MODULE_LICENSE("GPL"); 362 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov"); 363