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 24 static struct device_type mfd_dev_type = { 25 .name = "mfd_device", 26 }; 27 28 int mfd_cell_enable(struct platform_device *pdev) 29 { 30 const struct mfd_cell *cell = mfd_get_cell(pdev); 31 int err = 0; 32 33 /* only call enable hook if the cell wasn't previously enabled */ 34 if (atomic_inc_return(cell->usage_count) == 1) 35 err = cell->enable(pdev); 36 37 /* if the enable hook failed, decrement counter to allow retries */ 38 if (err) 39 atomic_dec(cell->usage_count); 40 41 return err; 42 } 43 EXPORT_SYMBOL(mfd_cell_enable); 44 45 int mfd_cell_disable(struct platform_device *pdev) 46 { 47 const struct mfd_cell *cell = mfd_get_cell(pdev); 48 int err = 0; 49 50 /* only disable if no other clients are using it */ 51 if (atomic_dec_return(cell->usage_count) == 0) 52 err = cell->disable(pdev); 53 54 /* if the disable hook failed, increment to allow retries */ 55 if (err) 56 atomic_inc(cell->usage_count); 57 58 /* sanity check; did someone call disable too many times? */ 59 WARN_ON(atomic_read(cell->usage_count) < 0); 60 61 return err; 62 } 63 EXPORT_SYMBOL(mfd_cell_disable); 64 65 static int mfd_platform_add_cell(struct platform_device *pdev, 66 const struct mfd_cell *cell) 67 { 68 if (!cell) 69 return 0; 70 71 pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL); 72 if (!pdev->mfd_cell) 73 return -ENOMEM; 74 75 return 0; 76 } 77 78 static int mfd_add_device(struct device *parent, int id, 79 const struct mfd_cell *cell, 80 struct resource *mem_base, 81 int irq_base, struct irq_domain *domain) 82 { 83 struct resource *res; 84 struct platform_device *pdev; 85 struct device_node *np = NULL; 86 int ret = -ENOMEM; 87 int r; 88 89 pdev = platform_device_alloc(cell->name, id + cell->id); 90 if (!pdev) 91 goto fail_alloc; 92 93 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL); 94 if (!res) 95 goto fail_device; 96 97 pdev->dev.parent = parent; 98 pdev->dev.type = &mfd_dev_type; 99 100 if (parent->of_node && cell->of_compatible) { 101 for_each_child_of_node(parent->of_node, np) { 102 if (of_device_is_compatible(np, cell->of_compatible)) { 103 pdev->dev.of_node = np; 104 break; 105 } 106 } 107 } 108 109 if (cell->pdata_size) { 110 ret = platform_device_add_data(pdev, 111 cell->platform_data, cell->pdata_size); 112 if (ret) 113 goto fail_res; 114 } 115 116 ret = mfd_platform_add_cell(pdev, cell); 117 if (ret) 118 goto fail_res; 119 120 for (r = 0; r < cell->num_resources; r++) { 121 res[r].name = cell->resources[r].name; 122 res[r].flags = cell->resources[r].flags; 123 124 /* Find out base to use */ 125 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) { 126 res[r].parent = mem_base; 127 res[r].start = mem_base->start + 128 cell->resources[r].start; 129 res[r].end = mem_base->start + 130 cell->resources[r].end; 131 } else if (cell->resources[r].flags & IORESOURCE_IRQ) { 132 if (domain) { 133 /* Unable to create mappings for IRQ ranges. */ 134 WARN_ON(cell->resources[r].start != 135 cell->resources[r].end); 136 res[r].start = res[r].end = irq_create_mapping( 137 domain, cell->resources[r].start); 138 } else { 139 res[r].start = irq_base + 140 cell->resources[r].start; 141 res[r].end = irq_base + 142 cell->resources[r].end; 143 } 144 } else { 145 res[r].parent = cell->resources[r].parent; 146 res[r].start = cell->resources[r].start; 147 res[r].end = cell->resources[r].end; 148 } 149 150 if (!cell->ignore_resource_conflicts) { 151 ret = acpi_check_resource_conflict(&res[r]); 152 if (ret) 153 goto fail_res; 154 } 155 } 156 157 ret = platform_device_add_resources(pdev, res, cell->num_resources); 158 if (ret) 159 goto fail_res; 160 161 ret = platform_device_add(pdev); 162 if (ret) 163 goto fail_res; 164 165 if (cell->pm_runtime_no_callbacks) 166 pm_runtime_no_callbacks(&pdev->dev); 167 168 kfree(res); 169 170 return 0; 171 172 fail_res: 173 kfree(res); 174 fail_device: 175 platform_device_put(pdev); 176 fail_alloc: 177 return ret; 178 } 179 180 int mfd_add_devices(struct device *parent, int id, 181 struct mfd_cell *cells, int n_devs, 182 struct resource *mem_base, 183 int irq_base, struct irq_domain *domain) 184 { 185 int i; 186 int ret = 0; 187 atomic_t *cnts; 188 189 /* initialize reference counting for all cells */ 190 cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL); 191 if (!cnts) 192 return -ENOMEM; 193 194 for (i = 0; i < n_devs; i++) { 195 atomic_set(&cnts[i], 0); 196 cells[i].usage_count = &cnts[i]; 197 ret = mfd_add_device(parent, id, cells + i, mem_base, 198 irq_base, domain); 199 if (ret) 200 break; 201 } 202 203 if (ret) 204 mfd_remove_devices(parent); 205 206 return ret; 207 } 208 EXPORT_SYMBOL(mfd_add_devices); 209 210 static int mfd_remove_devices_fn(struct device *dev, void *c) 211 { 212 struct platform_device *pdev; 213 const struct mfd_cell *cell; 214 atomic_t **usage_count = c; 215 216 if (dev->type != &mfd_dev_type) 217 return 0; 218 219 pdev = to_platform_device(dev); 220 cell = mfd_get_cell(pdev); 221 222 /* find the base address of usage_count pointers (for freeing) */ 223 if (!*usage_count || (cell->usage_count < *usage_count)) 224 *usage_count = cell->usage_count; 225 226 platform_device_unregister(pdev); 227 return 0; 228 } 229 230 void mfd_remove_devices(struct device *parent) 231 { 232 atomic_t *cnts = NULL; 233 234 device_for_each_child(parent, &cnts, mfd_remove_devices_fn); 235 kfree(cnts); 236 } 237 EXPORT_SYMBOL(mfd_remove_devices); 238 239 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones) 240 { 241 struct mfd_cell cell_entry; 242 struct device *dev; 243 struct platform_device *pdev; 244 int i; 245 246 /* fetch the parent cell's device (should already be registered!) */ 247 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell); 248 if (!dev) { 249 printk(KERN_ERR "failed to find device for cell %s\n", cell); 250 return -ENODEV; 251 } 252 pdev = to_platform_device(dev); 253 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry)); 254 255 WARN_ON(!cell_entry.enable); 256 257 for (i = 0; i < n_clones; i++) { 258 cell_entry.name = clones[i]; 259 /* don't give up if a single call fails; just report error */ 260 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0, 261 NULL)) 262 dev_err(dev, "failed to create platform device '%s'\n", 263 clones[i]); 264 } 265 266 return 0; 267 } 268 EXPORT_SYMBOL(mfd_clone_cell); 269 270 MODULE_LICENSE("GPL"); 271 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov"); 272