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 21 int mfd_cell_enable(struct platform_device *pdev) 22 { 23 const struct mfd_cell *cell = mfd_get_cell(pdev); 24 int err = 0; 25 26 /* only call enable hook if the cell wasn't previously enabled */ 27 if (atomic_inc_return(cell->usage_count) == 1) 28 err = cell->enable(pdev); 29 30 /* if the enable hook failed, decrement counter to allow retries */ 31 if (err) 32 atomic_dec(cell->usage_count); 33 34 return err; 35 } 36 EXPORT_SYMBOL(mfd_cell_enable); 37 38 int mfd_cell_disable(struct platform_device *pdev) 39 { 40 const struct mfd_cell *cell = mfd_get_cell(pdev); 41 int err = 0; 42 43 /* only disable if no other clients are using it */ 44 if (atomic_dec_return(cell->usage_count) == 0) 45 err = cell->disable(pdev); 46 47 /* if the disable hook failed, increment to allow retries */ 48 if (err) 49 atomic_inc(cell->usage_count); 50 51 /* sanity check; did someone call disable too many times? */ 52 WARN_ON(atomic_read(cell->usage_count) < 0); 53 54 return err; 55 } 56 EXPORT_SYMBOL(mfd_cell_disable); 57 58 static int mfd_platform_add_cell(struct platform_device *pdev, 59 const struct mfd_cell *cell) 60 { 61 if (!cell) 62 return 0; 63 64 pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL); 65 if (!pdev->mfd_cell) 66 return -ENOMEM; 67 68 return 0; 69 } 70 71 static int mfd_add_device(struct device *parent, int id, 72 const struct mfd_cell *cell, 73 struct resource *mem_base, 74 int irq_base) 75 { 76 struct resource *res; 77 struct platform_device *pdev; 78 int ret = -ENOMEM; 79 int r; 80 81 pdev = platform_device_alloc(cell->name, id + cell->id); 82 if (!pdev) 83 goto fail_alloc; 84 85 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL); 86 if (!res) 87 goto fail_device; 88 89 pdev->dev.parent = parent; 90 91 if (cell->pdata_size) { 92 ret = platform_device_add_data(pdev, 93 cell->platform_data, cell->pdata_size); 94 if (ret) 95 goto fail_res; 96 } 97 98 ret = mfd_platform_add_cell(pdev, cell); 99 if (ret) 100 goto fail_res; 101 102 for (r = 0; r < cell->num_resources; r++) { 103 res[r].name = cell->resources[r].name; 104 res[r].flags = cell->resources[r].flags; 105 106 /* Find out base to use */ 107 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) { 108 res[r].parent = mem_base; 109 res[r].start = mem_base->start + 110 cell->resources[r].start; 111 res[r].end = mem_base->start + 112 cell->resources[r].end; 113 } else if (cell->resources[r].flags & IORESOURCE_IRQ) { 114 res[r].start = irq_base + 115 cell->resources[r].start; 116 res[r].end = irq_base + 117 cell->resources[r].end; 118 } else { 119 res[r].parent = cell->resources[r].parent; 120 res[r].start = cell->resources[r].start; 121 res[r].end = cell->resources[r].end; 122 } 123 124 if (!cell->ignore_resource_conflicts) { 125 ret = acpi_check_resource_conflict(res); 126 if (ret) 127 goto fail_res; 128 } 129 } 130 131 ret = platform_device_add_resources(pdev, res, cell->num_resources); 132 if (ret) 133 goto fail_res; 134 135 ret = platform_device_add(pdev); 136 if (ret) 137 goto fail_res; 138 139 if (cell->pm_runtime_no_callbacks) 140 pm_runtime_no_callbacks(&pdev->dev); 141 142 kfree(res); 143 144 return 0; 145 146 fail_res: 147 kfree(res); 148 fail_device: 149 platform_device_put(pdev); 150 fail_alloc: 151 return ret; 152 } 153 154 int mfd_add_devices(struct device *parent, int id, 155 struct mfd_cell *cells, int n_devs, 156 struct resource *mem_base, 157 int irq_base) 158 { 159 int i; 160 int ret = 0; 161 atomic_t *cnts; 162 163 /* initialize reference counting for all cells */ 164 cnts = kcalloc(sizeof(*cnts), n_devs, GFP_KERNEL); 165 if (!cnts) 166 return -ENOMEM; 167 168 for (i = 0; i < n_devs; i++) { 169 atomic_set(&cnts[i], 0); 170 cells[i].usage_count = &cnts[i]; 171 ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base); 172 if (ret) 173 break; 174 } 175 176 if (ret) 177 mfd_remove_devices(parent); 178 179 return ret; 180 } 181 EXPORT_SYMBOL(mfd_add_devices); 182 183 static int mfd_remove_devices_fn(struct device *dev, void *c) 184 { 185 struct platform_device *pdev = to_platform_device(dev); 186 const struct mfd_cell *cell = mfd_get_cell(pdev); 187 atomic_t **usage_count = c; 188 189 /* find the base address of usage_count pointers (for freeing) */ 190 if (!*usage_count || (cell->usage_count < *usage_count)) 191 *usage_count = cell->usage_count; 192 193 platform_device_unregister(pdev); 194 return 0; 195 } 196 197 void mfd_remove_devices(struct device *parent) 198 { 199 atomic_t *cnts = NULL; 200 201 device_for_each_child(parent, &cnts, mfd_remove_devices_fn); 202 kfree(cnts); 203 } 204 EXPORT_SYMBOL(mfd_remove_devices); 205 206 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones) 207 { 208 struct mfd_cell cell_entry; 209 struct device *dev; 210 struct platform_device *pdev; 211 int i; 212 213 /* fetch the parent cell's device (should already be registered!) */ 214 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell); 215 if (!dev) { 216 printk(KERN_ERR "failed to find device for cell %s\n", cell); 217 return -ENODEV; 218 } 219 pdev = to_platform_device(dev); 220 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry)); 221 222 WARN_ON(!cell_entry.enable); 223 224 for (i = 0; i < n_clones; i++) { 225 cell_entry.name = clones[i]; 226 /* don't give up if a single call fails; just report error */ 227 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0)) 228 dev_err(dev, "failed to create platform device '%s'\n", 229 clones[i]); 230 } 231 232 return 0; 233 } 234 EXPORT_SYMBOL(mfd_clone_cell); 235 236 MODULE_LICENSE("GPL"); 237 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov"); 238