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 r; 129 130 pdev = platform_device_alloc(cell->name, id + cell->id); 131 if (!pdev) 132 goto fail_alloc; 133 134 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL); 135 if (!res) 136 goto fail_device; 137 138 pdev->dev.parent = parent; 139 pdev->dev.type = &mfd_dev_type; 140 pdev->dev.dma_mask = parent->dma_mask; 141 pdev->dev.dma_parms = parent->dma_parms; 142 pdev->dev.coherent_dma_mask = parent->coherent_dma_mask; 143 144 ret = regulator_bulk_register_supply_alias( 145 &pdev->dev, cell->parent_supplies, 146 parent, cell->parent_supplies, 147 cell->num_parent_supplies); 148 if (ret < 0) 149 goto fail_res; 150 151 if (parent->of_node && cell->of_compatible) { 152 for_each_child_of_node(parent->of_node, np) { 153 if (of_device_is_compatible(np, cell->of_compatible)) { 154 pdev->dev.of_node = np; 155 break; 156 } 157 } 158 } 159 160 mfd_acpi_add_device(cell, pdev); 161 162 if (cell->pdata_size) { 163 ret = platform_device_add_data(pdev, 164 cell->platform_data, cell->pdata_size); 165 if (ret) 166 goto fail_alias; 167 } 168 169 ret = mfd_platform_add_cell(pdev, cell, usage_count); 170 if (ret) 171 goto fail_alias; 172 173 for (r = 0; r < cell->num_resources; r++) { 174 res[r].name = cell->resources[r].name; 175 res[r].flags = cell->resources[r].flags; 176 177 /* Find out base to use */ 178 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) { 179 res[r].parent = mem_base; 180 res[r].start = mem_base->start + 181 cell->resources[r].start; 182 res[r].end = mem_base->start + 183 cell->resources[r].end; 184 } else if (cell->resources[r].flags & IORESOURCE_IRQ) { 185 if (domain) { 186 /* Unable to create mappings for IRQ ranges. */ 187 WARN_ON(cell->resources[r].start != 188 cell->resources[r].end); 189 res[r].start = res[r].end = irq_create_mapping( 190 domain, cell->resources[r].start); 191 } else { 192 res[r].start = irq_base + 193 cell->resources[r].start; 194 res[r].end = irq_base + 195 cell->resources[r].end; 196 } 197 } else { 198 res[r].parent = cell->resources[r].parent; 199 res[r].start = cell->resources[r].start; 200 res[r].end = cell->resources[r].end; 201 } 202 203 if (!cell->ignore_resource_conflicts) { 204 ret = acpi_check_resource_conflict(&res[r]); 205 if (ret) 206 goto fail_alias; 207 } 208 } 209 210 ret = platform_device_add_resources(pdev, res, cell->num_resources); 211 if (ret) 212 goto fail_alias; 213 214 ret = platform_device_add(pdev); 215 if (ret) 216 goto fail_alias; 217 218 if (cell->pm_runtime_no_callbacks) 219 pm_runtime_no_callbacks(&pdev->dev); 220 221 kfree(res); 222 223 return 0; 224 225 fail_alias: 226 regulator_bulk_unregister_supply_alias(&pdev->dev, 227 cell->parent_supplies, 228 cell->num_parent_supplies); 229 fail_res: 230 kfree(res); 231 fail_device: 232 platform_device_put(pdev); 233 fail_alloc: 234 return ret; 235 } 236 237 int mfd_add_devices(struct device *parent, int id, 238 const struct mfd_cell *cells, int n_devs, 239 struct resource *mem_base, 240 int irq_base, struct irq_domain *domain) 241 { 242 int i; 243 int ret; 244 atomic_t *cnts; 245 246 /* initialize reference counting for all cells */ 247 cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL); 248 if (!cnts) 249 return -ENOMEM; 250 251 for (i = 0; i < n_devs; i++) { 252 atomic_set(&cnts[i], 0); 253 ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base, 254 irq_base, domain); 255 if (ret) 256 goto fail; 257 } 258 259 return 0; 260 261 fail: 262 if (i) 263 mfd_remove_devices(parent); 264 else 265 kfree(cnts); 266 return ret; 267 } 268 EXPORT_SYMBOL(mfd_add_devices); 269 270 static int mfd_remove_devices_fn(struct device *dev, void *c) 271 { 272 struct platform_device *pdev; 273 const struct mfd_cell *cell; 274 atomic_t **usage_count = c; 275 276 if (dev->type != &mfd_dev_type) 277 return 0; 278 279 pdev = to_platform_device(dev); 280 cell = mfd_get_cell(pdev); 281 282 regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies, 283 cell->num_parent_supplies); 284 285 /* find the base address of usage_count pointers (for freeing) */ 286 if (!*usage_count || (cell->usage_count < *usage_count)) 287 *usage_count = cell->usage_count; 288 289 platform_device_unregister(pdev); 290 return 0; 291 } 292 293 void mfd_remove_devices(struct device *parent) 294 { 295 atomic_t *cnts = NULL; 296 297 device_for_each_child(parent, &cnts, mfd_remove_devices_fn); 298 kfree(cnts); 299 } 300 EXPORT_SYMBOL(mfd_remove_devices); 301 302 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones) 303 { 304 struct mfd_cell cell_entry; 305 struct device *dev; 306 struct platform_device *pdev; 307 int i; 308 309 /* fetch the parent cell's device (should already be registered!) */ 310 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell); 311 if (!dev) { 312 printk(KERN_ERR "failed to find device for cell %s\n", cell); 313 return -ENODEV; 314 } 315 pdev = to_platform_device(dev); 316 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry)); 317 318 WARN_ON(!cell_entry.enable); 319 320 for (i = 0; i < n_clones; i++) { 321 cell_entry.name = clones[i]; 322 /* don't give up if a single call fails; just report error */ 323 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, 324 cell_entry.usage_count, NULL, 0, NULL)) 325 dev_err(dev, "failed to create platform device '%s'\n", 326 clones[i]); 327 } 328 329 return 0; 330 } 331 EXPORT_SYMBOL(mfd_clone_cell); 332 333 MODULE_LICENSE("GPL"); 334 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov"); 335