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 22 int mfd_cell_enable(struct platform_device *pdev) 23 { 24 const struct mfd_cell *cell = mfd_get_cell(pdev); 25 int err = 0; 26 27 /* only call enable hook if the cell wasn't previously enabled */ 28 if (atomic_inc_return(cell->usage_count) == 1) 29 err = cell->enable(pdev); 30 31 /* if the enable hook failed, decrement counter to allow retries */ 32 if (err) 33 atomic_dec(cell->usage_count); 34 35 return err; 36 } 37 EXPORT_SYMBOL(mfd_cell_enable); 38 39 int mfd_cell_disable(struct platform_device *pdev) 40 { 41 const struct mfd_cell *cell = mfd_get_cell(pdev); 42 int err = 0; 43 44 /* only disable if no other clients are using it */ 45 if (atomic_dec_return(cell->usage_count) == 0) 46 err = cell->disable(pdev); 47 48 /* if the disable hook failed, increment to allow retries */ 49 if (err) 50 atomic_inc(cell->usage_count); 51 52 /* sanity check; did someone call disable too many times? */ 53 WARN_ON(atomic_read(cell->usage_count) < 0); 54 55 return err; 56 } 57 EXPORT_SYMBOL(mfd_cell_disable); 58 59 static int mfd_platform_add_cell(struct platform_device *pdev, 60 const struct mfd_cell *cell) 61 { 62 if (!cell) 63 return 0; 64 65 pdev->mfd_cell = kmemdup(cell, sizeof(*cell), GFP_KERNEL); 66 if (!pdev->mfd_cell) 67 return -ENOMEM; 68 69 return 0; 70 } 71 72 static int mfd_add_device(struct device *parent, int id, 73 const struct mfd_cell *cell, 74 struct resource *mem_base, 75 int irq_base) 76 { 77 struct resource *res; 78 struct platform_device *pdev; 79 int ret = -ENOMEM; 80 int r; 81 82 pdev = platform_device_alloc(cell->name, id + cell->id); 83 if (!pdev) 84 goto fail_alloc; 85 86 res = kzalloc(sizeof(*res) * cell->num_resources, GFP_KERNEL); 87 if (!res) 88 goto fail_device; 89 90 pdev->dev.parent = parent; 91 92 if (cell->pdata_size) { 93 ret = platform_device_add_data(pdev, 94 cell->platform_data, cell->pdata_size); 95 if (ret) 96 goto fail_res; 97 } 98 99 ret = mfd_platform_add_cell(pdev, cell); 100 if (ret) 101 goto fail_res; 102 103 for (r = 0; r < cell->num_resources; r++) { 104 res[r].name = cell->resources[r].name; 105 res[r].flags = cell->resources[r].flags; 106 107 /* Find out base to use */ 108 if ((cell->resources[r].flags & IORESOURCE_MEM) && mem_base) { 109 res[r].parent = mem_base; 110 res[r].start = mem_base->start + 111 cell->resources[r].start; 112 res[r].end = mem_base->start + 113 cell->resources[r].end; 114 } else if (cell->resources[r].flags & IORESOURCE_IRQ) { 115 res[r].start = irq_base + 116 cell->resources[r].start; 117 res[r].end = irq_base + 118 cell->resources[r].end; 119 } else { 120 res[r].parent = cell->resources[r].parent; 121 res[r].start = cell->resources[r].start; 122 res[r].end = cell->resources[r].end; 123 } 124 125 if (!cell->ignore_resource_conflicts) { 126 ret = acpi_check_resource_conflict(res); 127 if (ret) 128 goto fail_res; 129 } 130 } 131 132 ret = platform_device_add_resources(pdev, res, cell->num_resources); 133 if (ret) 134 goto fail_res; 135 136 ret = platform_device_add(pdev); 137 if (ret) 138 goto fail_res; 139 140 if (cell->pm_runtime_no_callbacks) 141 pm_runtime_no_callbacks(&pdev->dev); 142 143 kfree(res); 144 145 return 0; 146 147 fail_res: 148 kfree(res); 149 fail_device: 150 platform_device_put(pdev); 151 fail_alloc: 152 return ret; 153 } 154 155 int mfd_add_devices(struct device *parent, int id, 156 struct mfd_cell *cells, int n_devs, 157 struct resource *mem_base, 158 int irq_base) 159 { 160 int i; 161 int ret = 0; 162 atomic_t *cnts; 163 164 /* initialize reference counting for all cells */ 165 cnts = kcalloc(sizeof(*cnts), n_devs, GFP_KERNEL); 166 if (!cnts) 167 return -ENOMEM; 168 169 for (i = 0; i < n_devs; i++) { 170 atomic_set(&cnts[i], 0); 171 cells[i].usage_count = &cnts[i]; 172 ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base); 173 if (ret) 174 break; 175 } 176 177 if (ret) 178 mfd_remove_devices(parent); 179 180 return ret; 181 } 182 EXPORT_SYMBOL(mfd_add_devices); 183 184 static int mfd_remove_devices_fn(struct device *dev, void *c) 185 { 186 struct platform_device *pdev = to_platform_device(dev); 187 const struct mfd_cell *cell = mfd_get_cell(pdev); 188 atomic_t **usage_count = c; 189 190 /* find the base address of usage_count pointers (for freeing) */ 191 if (!*usage_count || (cell->usage_count < *usage_count)) 192 *usage_count = cell->usage_count; 193 194 platform_device_unregister(pdev); 195 return 0; 196 } 197 198 void mfd_remove_devices(struct device *parent) 199 { 200 atomic_t *cnts = NULL; 201 202 device_for_each_child(parent, &cnts, mfd_remove_devices_fn); 203 kfree(cnts); 204 } 205 EXPORT_SYMBOL(mfd_remove_devices); 206 207 int mfd_clone_cell(const char *cell, const char **clones, size_t n_clones) 208 { 209 struct mfd_cell cell_entry; 210 struct device *dev; 211 struct platform_device *pdev; 212 int i; 213 214 /* fetch the parent cell's device (should already be registered!) */ 215 dev = bus_find_device_by_name(&platform_bus_type, NULL, cell); 216 if (!dev) { 217 printk(KERN_ERR "failed to find device for cell %s\n", cell); 218 return -ENODEV; 219 } 220 pdev = to_platform_device(dev); 221 memcpy(&cell_entry, mfd_get_cell(pdev), sizeof(cell_entry)); 222 223 WARN_ON(!cell_entry.enable); 224 225 for (i = 0; i < n_clones; i++) { 226 cell_entry.name = clones[i]; 227 /* don't give up if a single call fails; just report error */ 228 if (mfd_add_device(pdev->dev.parent, -1, &cell_entry, NULL, 0)) 229 dev_err(dev, "failed to create platform device '%s'\n", 230 clones[i]); 231 } 232 233 return 0; 234 } 235 EXPORT_SYMBOL(mfd_clone_cell); 236 237 MODULE_LICENSE("GPL"); 238 MODULE_AUTHOR("Ian Molton, Dmitry Baryshkov"); 239