.. | .. |
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11 | 11 | #include <linux/device.h> |
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12 | 12 | #include <linux/kref.h> |
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13 | 13 | #include <linux/list.h> |
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14 | | -#include <linux/module.h> |
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15 | 14 | #include <linux/mutex.h> |
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16 | 15 | #include <linux/slab.h> |
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17 | 16 | #include <linux/debugfs.h> |
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| 17 | + |
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| 18 | +/** |
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| 19 | + * DOC: overview |
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| 20 | + * |
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| 21 | + * The component helper allows drivers to collect a pile of sub-devices, |
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| 22 | + * including their bound drivers, into an aggregate driver. Various subsystems |
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| 23 | + * already provide functions to get hold of such components, e.g. |
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| 24 | + * of_clk_get_by_name(). The component helper can be used when such a |
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| 25 | + * subsystem-specific way to find a device is not available: The component |
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| 26 | + * helper fills the niche of aggregate drivers for specific hardware, where |
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| 27 | + * further standardization into a subsystem would not be practical. The common |
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| 28 | + * example is when a logical device (e.g. a DRM display driver) is spread around |
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| 29 | + * the SoC on various components (scanout engines, blending blocks, transcoders |
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| 30 | + * for various outputs and so on). |
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| 31 | + * |
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| 32 | + * The component helper also doesn't solve runtime dependencies, e.g. for system |
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| 33 | + * suspend and resume operations. See also :ref:`device links<device_link>`. |
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| 34 | + * |
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| 35 | + * Components are registered using component_add() and unregistered with |
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| 36 | + * component_del(), usually from the driver's probe and disconnect functions. |
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| 37 | + * |
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| 38 | + * Aggregate drivers first assemble a component match list of what they need |
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| 39 | + * using component_match_add(). This is then registered as an aggregate driver |
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| 40 | + * using component_master_add_with_match(), and unregistered using |
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| 41 | + * component_master_del(). |
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| 42 | + */ |
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18 | 43 | |
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19 | 44 | struct component; |
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20 | 45 | |
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21 | 46 | struct component_match_array { |
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22 | 47 | void *data; |
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23 | 48 | int (*compare)(struct device *, void *); |
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| 49 | + int (*compare_typed)(struct device *, int, void *); |
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24 | 50 | void (*release)(struct device *, void *); |
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25 | 51 | struct component *component; |
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26 | 52 | bool duplicate; |
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.. | .. |
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48 | 74 | bool bound; |
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49 | 75 | |
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50 | 76 | const struct component_ops *ops; |
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| 77 | + int subcomponent; |
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51 | 78 | struct device *dev; |
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52 | 79 | }; |
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53 | 80 | |
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.. | .. |
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85 | 112 | return 0; |
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86 | 113 | } |
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87 | 114 | |
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88 | | -static int component_devices_open(struct inode *inode, struct file *file) |
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89 | | -{ |
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90 | | - return single_open(file, component_devices_show, inode->i_private); |
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91 | | -} |
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92 | | - |
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93 | | -static const struct file_operations component_devices_fops = { |
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94 | | - .open = component_devices_open, |
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95 | | - .read = seq_read, |
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96 | | - .llseek = seq_lseek, |
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97 | | - .release = single_release, |
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98 | | -}; |
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| 115 | +DEFINE_SHOW_ATTRIBUTE(component_devices); |
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99 | 116 | |
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100 | 117 | static int __init component_debug_init(void) |
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101 | 118 | { |
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.. | .. |
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142 | 159 | } |
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143 | 160 | |
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144 | 161 | static struct component *find_component(struct master *master, |
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145 | | - int (*compare)(struct device *, void *), void *compare_data) |
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| 162 | + struct component_match_array *mc) |
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146 | 163 | { |
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147 | 164 | struct component *c; |
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148 | 165 | |
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.. | .. |
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150 | 167 | if (c->master && c->master != master) |
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151 | 168 | continue; |
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152 | 169 | |
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153 | | - if (compare(c->dev, compare_data)) |
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| 170 | + if (mc->compare && mc->compare(c->dev, mc->data)) |
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| 171 | + return c; |
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| 172 | + |
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| 173 | + if (mc->compare_typed && |
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| 174 | + mc->compare_typed(c->dev, c->subcomponent, mc->data)) |
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154 | 175 | return c; |
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155 | 176 | } |
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156 | 177 | |
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.. | .. |
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176 | 197 | if (match->compare[i].component) |
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177 | 198 | continue; |
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178 | 199 | |
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179 | | - c = find_component(master, mc->compare, mc->data); |
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| 200 | + c = find_component(master, mc); |
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180 | 201 | if (!c) { |
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181 | 202 | ret = -ENXIO; |
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182 | 203 | break; |
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.. | .. |
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312 | 333 | return 0; |
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313 | 334 | } |
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314 | 335 | |
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315 | | -/* |
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316 | | - * Add a component to be matched, with a release function. |
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317 | | - * |
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318 | | - * The match array is first created or extended if necessary. |
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319 | | - */ |
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320 | | -void component_match_add_release(struct device *master, |
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| 336 | +static void __component_match_add(struct device *master, |
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321 | 337 | struct component_match **matchptr, |
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322 | 338 | void (*release)(struct device *, void *), |
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323 | | - int (*compare)(struct device *, void *), void *compare_data) |
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| 339 | + int (*compare)(struct device *, void *), |
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| 340 | + int (*compare_typed)(struct device *, int, void *), |
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| 341 | + void *compare_data) |
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324 | 342 | { |
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325 | 343 | struct component_match *match = *matchptr; |
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326 | 344 | |
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.. | .. |
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352 | 370 | } |
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353 | 371 | |
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354 | 372 | match->compare[match->num].compare = compare; |
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| 373 | + match->compare[match->num].compare_typed = compare_typed; |
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355 | 374 | match->compare[match->num].release = release; |
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356 | 375 | match->compare[match->num].data = compare_data; |
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357 | 376 | match->compare[match->num].component = NULL; |
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358 | 377 | match->num++; |
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359 | 378 | } |
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| 379 | + |
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| 380 | +/** |
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| 381 | + * component_match_add_release - add a component match entry with release callback |
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| 382 | + * @master: device with the aggregate driver |
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| 383 | + * @matchptr: pointer to the list of component matches |
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| 384 | + * @release: release function for @compare_data |
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| 385 | + * @compare: compare function to match against all components |
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| 386 | + * @compare_data: opaque pointer passed to the @compare function |
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| 387 | + * |
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| 388 | + * Adds a new component match to the list stored in @matchptr, which the @master |
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| 389 | + * aggregate driver needs to function. The list of component matches pointed to |
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| 390 | + * by @matchptr must be initialized to NULL before adding the first match. This |
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| 391 | + * only matches against components added with component_add(). |
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| 392 | + * |
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| 393 | + * The allocated match list in @matchptr is automatically released using devm |
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| 394 | + * actions, where upon @release will be called to free any references held by |
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| 395 | + * @compare_data, e.g. when @compare_data is a &device_node that must be |
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| 396 | + * released with of_node_put(). |
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| 397 | + * |
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| 398 | + * See also component_match_add() and component_match_add_typed(). |
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| 399 | + */ |
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| 400 | +void component_match_add_release(struct device *master, |
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| 401 | + struct component_match **matchptr, |
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| 402 | + void (*release)(struct device *, void *), |
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| 403 | + int (*compare)(struct device *, void *), void *compare_data) |
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| 404 | +{ |
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| 405 | + __component_match_add(master, matchptr, release, compare, NULL, |
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| 406 | + compare_data); |
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| 407 | +} |
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360 | 408 | EXPORT_SYMBOL(component_match_add_release); |
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| 409 | + |
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| 410 | +/** |
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| 411 | + * component_match_add_typed - add a component match entry for a typed component |
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| 412 | + * @master: device with the aggregate driver |
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| 413 | + * @matchptr: pointer to the list of component matches |
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| 414 | + * @compare_typed: compare function to match against all typed components |
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| 415 | + * @compare_data: opaque pointer passed to the @compare function |
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| 416 | + * |
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| 417 | + * Adds a new component match to the list stored in @matchptr, which the @master |
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| 418 | + * aggregate driver needs to function. The list of component matches pointed to |
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| 419 | + * by @matchptr must be initialized to NULL before adding the first match. This |
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| 420 | + * only matches against components added with component_add_typed(). |
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| 421 | + * |
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| 422 | + * The allocated match list in @matchptr is automatically released using devm |
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| 423 | + * actions. |
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| 424 | + * |
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| 425 | + * See also component_match_add_release() and component_match_add_typed(). |
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| 426 | + */ |
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| 427 | +void component_match_add_typed(struct device *master, |
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| 428 | + struct component_match **matchptr, |
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| 429 | + int (*compare_typed)(struct device *, int, void *), void *compare_data) |
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| 430 | +{ |
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| 431 | + __component_match_add(master, matchptr, NULL, NULL, compare_typed, |
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| 432 | + compare_data); |
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| 433 | +} |
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| 434 | +EXPORT_SYMBOL(component_match_add_typed); |
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361 | 435 | |
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362 | 436 | static void free_master(struct master *master) |
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363 | 437 | { |
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.. | .. |
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378 | 452 | kfree(master); |
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379 | 453 | } |
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380 | 454 | |
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| 455 | +/** |
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| 456 | + * component_master_add_with_match - register an aggregate driver |
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| 457 | + * @dev: device with the aggregate driver |
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| 458 | + * @ops: callbacks for the aggregate driver |
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| 459 | + * @match: component match list for the aggregate driver |
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| 460 | + * |
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| 461 | + * Registers a new aggregate driver consisting of the components added to @match |
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| 462 | + * by calling one of the component_match_add() functions. Once all components in |
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| 463 | + * @match are available, it will be assembled by calling |
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| 464 | + * &component_master_ops.bind from @ops. Must be unregistered by calling |
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| 465 | + * component_master_del(). |
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| 466 | + */ |
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381 | 467 | int component_master_add_with_match(struct device *dev, |
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382 | 468 | const struct component_master_ops *ops, |
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383 | 469 | struct component_match *match) |
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.. | .. |
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414 | 500 | } |
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415 | 501 | EXPORT_SYMBOL_GPL(component_master_add_with_match); |
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416 | 502 | |
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| 503 | +/** |
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| 504 | + * component_master_del - unregister an aggregate driver |
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| 505 | + * @dev: device with the aggregate driver |
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| 506 | + * @ops: callbacks for the aggregate driver |
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| 507 | + * |
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| 508 | + * Unregisters an aggregate driver registered with |
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| 509 | + * component_master_add_with_match(). If necessary the aggregate driver is first |
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| 510 | + * disassembled by calling &component_master_ops.unbind from @ops. |
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| 511 | + */ |
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417 | 512 | void component_master_del(struct device *dev, |
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418 | 513 | const struct component_master_ops *ops) |
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419 | 514 | { |
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.. | .. |
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434 | 529 | { |
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435 | 530 | WARN_ON(!component->bound); |
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436 | 531 | |
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437 | | - component->ops->unbind(component->dev, master->dev, data); |
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| 532 | + if (component->ops && component->ops->unbind) |
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| 533 | + component->ops->unbind(component->dev, master->dev, data); |
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438 | 534 | component->bound = false; |
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439 | 535 | |
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440 | 536 | /* Release all resources claimed in the binding of this component */ |
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441 | 537 | devres_release_group(component->dev, component); |
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442 | 538 | } |
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443 | 539 | |
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| 540 | +/** |
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| 541 | + * component_unbind_all - unbind all components of an aggregate driver |
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| 542 | + * @master_dev: device with the aggregate driver |
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| 543 | + * @data: opaque pointer, passed to all components |
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| 544 | + * |
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| 545 | + * Unbinds all components of the aggregate @dev by passing @data to their |
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| 546 | + * &component_ops.unbind functions. Should be called from |
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| 547 | + * &component_master_ops.unbind. |
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| 548 | + */ |
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444 | 549 | void component_unbind_all(struct device *master_dev, void *data) |
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445 | 550 | { |
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446 | 551 | struct master *master; |
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.. | .. |
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515 | 620 | return ret; |
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516 | 621 | } |
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517 | 622 | |
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| 623 | +/** |
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| 624 | + * component_bind_all - bind all components of an aggregate driver |
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| 625 | + * @master_dev: device with the aggregate driver |
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| 626 | + * @data: opaque pointer, passed to all components |
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| 627 | + * |
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| 628 | + * Binds all components of the aggregate @dev by passing @data to their |
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| 629 | + * &component_ops.bind functions. Should be called from |
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| 630 | + * &component_master_ops.bind. |
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| 631 | + */ |
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518 | 632 | int component_bind_all(struct device *master_dev, void *data) |
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519 | 633 | { |
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520 | 634 | struct master *master; |
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.. | .. |
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549 | 663 | } |
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550 | 664 | EXPORT_SYMBOL_GPL(component_bind_all); |
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551 | 665 | |
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552 | | -int component_add(struct device *dev, const struct component_ops *ops) |
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| 666 | +static int __component_add(struct device *dev, const struct component_ops *ops, |
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| 667 | + int subcomponent) |
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553 | 668 | { |
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554 | 669 | struct component *component; |
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555 | 670 | int ret; |
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.. | .. |
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560 | 675 | |
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561 | 676 | component->ops = ops; |
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562 | 677 | component->dev = dev; |
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| 678 | + component->subcomponent = subcomponent; |
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563 | 679 | |
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564 | 680 | dev_dbg(dev, "adding component (ops %ps)\n", ops); |
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565 | 681 | |
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.. | .. |
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578 | 694 | |
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579 | 695 | return ret < 0 ? ret : 0; |
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580 | 696 | } |
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| 697 | + |
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| 698 | +/** |
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| 699 | + * component_add_typed - register a component |
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| 700 | + * @dev: component device |
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| 701 | + * @ops: component callbacks |
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| 702 | + * @subcomponent: nonzero identifier for subcomponents |
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| 703 | + * |
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| 704 | + * Register a new component for @dev. Functions in @ops will be call when the |
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| 705 | + * aggregate driver is ready to bind the overall driver by calling |
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| 706 | + * component_bind_all(). See also &struct component_ops. |
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| 707 | + * |
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| 708 | + * @subcomponent must be nonzero and is used to differentiate between multiple |
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| 709 | + * components registerd on the same device @dev. These components are match |
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| 710 | + * using component_match_add_typed(). |
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| 711 | + * |
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| 712 | + * The component needs to be unregistered at driver unload/disconnect by |
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| 713 | + * calling component_del(). |
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| 714 | + * |
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| 715 | + * See also component_add(). |
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| 716 | + */ |
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| 717 | +int component_add_typed(struct device *dev, const struct component_ops *ops, |
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| 718 | + int subcomponent) |
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| 719 | +{ |
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| 720 | + if (WARN_ON(subcomponent == 0)) |
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| 721 | + return -EINVAL; |
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| 722 | + |
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| 723 | + return __component_add(dev, ops, subcomponent); |
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| 724 | +} |
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| 725 | +EXPORT_SYMBOL_GPL(component_add_typed); |
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| 726 | + |
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| 727 | +/** |
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| 728 | + * component_add - register a component |
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| 729 | + * @dev: component device |
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| 730 | + * @ops: component callbacks |
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| 731 | + * |
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| 732 | + * Register a new component for @dev. Functions in @ops will be called when the |
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| 733 | + * aggregate driver is ready to bind the overall driver by calling |
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| 734 | + * component_bind_all(). See also &struct component_ops. |
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| 735 | + * |
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| 736 | + * The component needs to be unregistered at driver unload/disconnect by |
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| 737 | + * calling component_del(). |
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| 738 | + * |
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| 739 | + * See also component_add_typed() for a variant that allows multipled different |
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| 740 | + * components on the same device. |
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| 741 | + */ |
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| 742 | +int component_add(struct device *dev, const struct component_ops *ops) |
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| 743 | +{ |
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| 744 | + return __component_add(dev, ops, 0); |
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| 745 | +} |
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581 | 746 | EXPORT_SYMBOL_GPL(component_add); |
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582 | 747 | |
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| 748 | +/** |
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| 749 | + * component_del - unregister a component |
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| 750 | + * @dev: component device |
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| 751 | + * @ops: component callbacks |
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| 752 | + * |
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| 753 | + * Unregister a component added with component_add(). If the component is bound |
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| 754 | + * into an aggregate driver, this will force the entire aggregate driver, including |
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| 755 | + * all its components, to be unbound. |
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| 756 | + */ |
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583 | 757 | void component_del(struct device *dev, const struct component_ops *ops) |
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584 | 758 | { |
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585 | 759 | struct component *c, *component = NULL; |
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.. | .. |
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603 | 777 | kfree(component); |
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604 | 778 | } |
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605 | 779 | EXPORT_SYMBOL_GPL(component_del); |
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606 | | - |
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607 | | -MODULE_LICENSE("GPL v2"); |
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