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 struct acpi_device *parent_adev; 86 struct acpi_device *adev; 87 88 parent_adev = ACPI_COMPANION(pdev->dev.parent); 89 if (!parent_adev) 90 return; 91 92 /* 93 * MFD child device gets its ACPI handle either from the ACPI 94 * device directly under the parent that matches the acpi_pnpid or 95 * it will use the parent handle if is no acpi_pnpid is given. 96 */ 97 adev = parent_adev; 98 if (cell->acpi_pnpid) { 99 struct acpi_device_id ids[2] = {}; 100 struct acpi_device *child_adev; 101 102 strlcpy(ids[0].id, cell->acpi_pnpid, sizeof(ids[0].id)); 103 list_for_each_entry(child_adev, &parent_adev->children, node) 104 if (acpi_match_device_ids(child_adev, ids)) { 105 adev = child_adev; 106 break; 107 } 108 } 109 110 ACPI_COMPANION_SET(&pdev->dev, adev); 111 } 112 #else 113 static inline void mfd_acpi_add_device(const struct mfd_cell *cell, 114 struct platform_device *pdev) 115 { 116 } 117 #endif 118 119 static int mfd_add_device(struct device *parent, int id, 120 const struct mfd_cell *cell, atomic_t *usage_count, 121 struct resource *mem_base, 122 int irq_base, struct irq_domain *domain) 123 { 124 struct resource *res; 125 struct platform_device *pdev; 126 struct device_node *np = NULL; 127 int ret = -ENOMEM; 128 int platform_id; 129 int r; 130 131 if (id == PLATFORM_DEVID_AUTO) 132 platform_id = id; 133 else 134 platform_id = id + cell->id; 135 136 pdev = platform_device_alloc(cell->name, platform_id); 137 if (!pdev) 138 goto fail_alloc; 139 140 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL); 141 if (!res) 142 goto fail_device; 143 144 pdev->dev.parent = parent; 145 pdev->dev.type = &mfd_dev_type; 146 pdev->dev.dma_mask = parent->dma_mask; 147 pdev->dev.dma_parms = parent->dma_parms; 148 pdev->dev.coherent_dma_mask = parent->coherent_dma_mask; 149 150 ret = regulator_bulk_register_supply_alias( 151 &pdev->dev, cell->parent_supplies, 152 parent, cell->parent_supplies, 153 cell->num_parent_supplies); 154 if (ret < 0) 155 goto fail_res; 156 157 if (parent->of_node && cell->of_compatible) { 158 for_each_child_of_node(parent->of_node, np) { 159 if (of_device_is_compatible(np, cell->of_compatible)) { 160 pdev->dev.of_node = np; 161 break; 162 } 163 } 164 } 165 166 mfd_acpi_add_device(cell, pdev); 167 168 if (cell->pdata_size) { 169 ret = platform_device_add_data(pdev, 170 cell->platform_data, cell->pdata_size); 171 if (ret) 172 goto fail_alias; 173 } 174 175 ret = mfd_platform_add_cell(pdev, cell, usage_count); 176 if (ret) 177 goto fail_alias; 178 179 for (r = 0; r < cell->num_resources; r++) { 180 res[r].name = cell->resources[r].name; 181 res[r].flags = cell->resources[r].flags; 182 183 /* Find out base to use */ 184 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) { 185 res[r].parent = mem_base; 186 res[r].start = mem_base->start + 187 cell->resources[r].start; 188 res[r].end = mem_base->start + 189 cell->resources[r].end; 190 } else if (cell->resources[r].flags & IORESOURCE_IRQ) { 191 if (domain) { 192 /* Unable to create mappings for IRQ ranges. */ 193 WARN_ON(cell->resources[r].start != 194 cell->resources[r].end); 195 res[r].start = res[r].end = irq_create_mapping( 196 domain, cell->resources[r].start); 197 } else { 198 res[r].start = irq_base + 199 cell->resources[r].start; 200 res[r].end = irq_base + 201 cell->resources[r].end; 202 } 203 } else { 204 res[r].parent = cell->resources[r].parent; 205 res[r].start = cell->resources[r].start; 206 res[r].end = cell->resources[r].end; 207 } 208 209 if (!cell->ignore_resource_conflicts) { 210 if (has_acpi_companion(&pdev->dev)) { 211 ret = acpi_check_resource_conflict(&res[r]); 212 if (ret) 213 goto fail_alias; 214 } 215 } 216 } 217 218 ret = platform_device_add_resources(pdev, res, cell->num_resources); 219 if (ret) 220 goto fail_alias; 221 222 ret = platform_device_add(pdev); 223 if (ret) 224 goto fail_alias; 225 226 if (cell->pm_runtime_no_callbacks) 227 pm_runtime_no_callbacks(&pdev->dev); 228 229 kfree(res); 230 231 return 0; 232 233 fail_alias: 234 regulator_bulk_unregister_supply_alias(&pdev->dev, 235 cell->parent_supplies, 236 cell->num_parent_supplies); 237 fail_res: 238 kfree(res); 239 fail_device: 240 platform_device_put(pdev); 241 fail_alloc: 242 return ret; 243 } 244 245 int mfd_add_devices(struct device *parent, int id, 246 const struct mfd_cell *cells, int n_devs, 247 struct resource *mem_base, 248 int irq_base, struct irq_domain *domain) 249 { 250 int i; 251 int ret; 252 atomic_t *cnts; 253 254 /* initialize reference counting for all cells */ 255 cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL); 256 if (!cnts) 257 return -ENOMEM; 258 259 for (i = 0; i < n_devs; i++) { 260 atomic_set(&cnts[i], 0); 261 ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base, 262 irq_base, domain); 263 if (ret) 264 goto fail; 265 } 266 267 return 0; 268 269 fail: 270 if (i) 271 mfd_remove_devices(parent); 272 else 273 kfree(cnts); 274 return ret; 275 } 276 EXPORT_SYMBOL(mfd_add_devices); 277 278 static int mfd_remove_devices_fn(struct device *dev, void *c) 279 { 280 struct platform_device *pdev; 281 const struct mfd_cell *cell; 282 atomic_t **usage_count = c; 283 284 if (dev->type != &mfd_dev_type) 285 return 0; 286 287 pdev = to_platform_device(dev); 288 cell = mfd_get_cell(pdev); 289 290 regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies, 291 cell->num_parent_supplies); 292 293 /* find the base address of usage_count pointers (for freeing) */ 294 if (!*usage_count || (cell->usage_count < *usage_count)) 295 *usage_count = cell->usage_count; 296 297 platform_device_unregister(pdev); 298 return 0; 299 } 300 301 void mfd_remove_devices(struct device *parent) 302 { 303 atomic_t *cnts = NULL; 304 305 device_for_each_child(parent, &cnts, mfd_remove_devices_fn); 306 kfree(cnts); 307 } 308 EXPORT_SYMBOL(mfd_remove_devices); 309 310 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones) 311 { 312 struct mfd_cell cell_entry; 313 struct device *dev; 314 struct platform_device *pdev; 315 int i; 316 317 /* fetch the parent cell's device (should already be registered!) */ 318 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell); 319 if (!dev) { 320 printk(KERN_ERR "failed to find device for cell %s\n", cell); 321 return -ENODEV; 322 } 323 pdev = to_platform_device(dev); 324 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry)); 325 326 WARN_ON(!cell_entry.enable); 327 328 for (i = 0; i < n_clones; i++) { 329 cell_entry.name = clones[i]; 330 /* don't give up if a single call fails; just report error */ 331 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, 332 cell_entry.usage_count, NULL, 0, NULL)) 333 dev_err(dev, "failed to create platform device '%s'\n", 334 clones[i]); 335 } 336 337 return 0; 338 } 339 EXPORT_SYMBOL(mfd_clone_cell); 340 341 MODULE_LICENSE("GPL"); 342 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov"); 343