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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Linux I2C core ACPI support code4 *5 * Copyright (C) 2014 Intel Corp, Author: Lan Tianyu <tianyu.lan@intel.com>6 */7 8#include <linux/acpi.h>9#include <linux/device.h>10#include <linux/err.h>11#include <linux/i2c.h>12#include <linux/list.h>13#include <linux/module.h>14#include <linux/slab.h>15 16#include "i2c-core.h"17 18struct i2c_acpi_handler_data {19 struct acpi_connection_info info;20 struct i2c_adapter *adapter;21};22 23struct gsb_buffer {24 u8 status;25 u8 len;26 union {27 u16 wdata;28 u8 bdata;29 DECLARE_FLEX_ARRAY(u8, data);30 };31} __packed;32 33struct i2c_acpi_lookup {34 struct i2c_board_info *info;35 acpi_handle adapter_handle;36 acpi_handle device_handle;37 acpi_handle search_handle;38 int n;39 int index;40 u32 speed;41 u32 min_speed;42 u32 force_speed;43};44 45/**46 * i2c_acpi_get_i2c_resource - Gets I2cSerialBus resource if type matches47 * @ares: ACPI resource48 * @i2c: Pointer to I2cSerialBus resource will be returned here49 *50 * Checks if the given ACPI resource is of type I2cSerialBus.51 * In this case, returns a pointer to it to the caller.52 *53 * Returns true if resource type is of I2cSerialBus, otherwise false.54 */55bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,56 struct acpi_resource_i2c_serialbus **i2c)57{58 struct acpi_resource_i2c_serialbus *sb;59 60 if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)61 return false;62 63 sb = &ares->data.i2c_serial_bus;64 if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)65 return false;66 67 *i2c = sb;68 return true;69}70EXPORT_SYMBOL_GPL(i2c_acpi_get_i2c_resource);71 72static int i2c_acpi_resource_count(struct acpi_resource *ares, void *data)73{74 struct acpi_resource_i2c_serialbus *sb;75 int *count = data;76 77 if (i2c_acpi_get_i2c_resource(ares, &sb))78 *count = *count + 1;79 80 return 1;81}82 83/**84 * i2c_acpi_client_count - Count the number of I2cSerialBus resources85 * @adev: ACPI device86 *87 * Returns the number of I2cSerialBus resources in the ACPI-device's88 * resource-list; or a negative error code.89 */90int i2c_acpi_client_count(struct acpi_device *adev)91{92 int ret, count = 0;93 LIST_HEAD(r);94 95 ret = acpi_dev_get_resources(adev, &r, i2c_acpi_resource_count, &count);96 if (ret < 0)97 return ret;98 99 acpi_dev_free_resource_list(&r);100 return count;101}102EXPORT_SYMBOL_GPL(i2c_acpi_client_count);103 104static int i2c_acpi_fill_info(struct acpi_resource *ares, void *data)105{106 struct i2c_acpi_lookup *lookup = data;107 struct i2c_board_info *info = lookup->info;108 struct acpi_resource_i2c_serialbus *sb;109 acpi_status status;110 111 if (info->addr || !i2c_acpi_get_i2c_resource(ares, &sb))112 return 1;113 114 if (lookup->index != -1 && lookup->n++ != lookup->index)115 return 1;116 117 status = acpi_get_handle(lookup->device_handle,118 sb->resource_source.string_ptr,119 &lookup->adapter_handle);120 if (ACPI_FAILURE(status))121 return 1;122 123 info->addr = sb->slave_address;124 lookup->speed = sb->connection_speed;125 if (sb->access_mode == ACPI_I2C_10BIT_MODE)126 info->flags |= I2C_CLIENT_TEN;127 128 return 1;129}130 131static const struct acpi_device_id i2c_acpi_ignored_device_ids[] = {132 /*133 * ACPI video acpi_devices, which are handled by the acpi-video driver134 * sometimes contain a SERIAL_TYPE_I2C ACPI resource, ignore these.135 */136 { ACPI_VIDEO_HID, 0 },137 {}138};139 140struct i2c_acpi_irq_context {141 int irq;142 bool wake_capable;143};144 145static int i2c_acpi_do_lookup(struct acpi_device *adev,146 struct i2c_acpi_lookup *lookup)147{148 struct i2c_board_info *info = lookup->info;149 struct list_head resource_list;150 int ret;151 152 if (acpi_bus_get_status(adev))153 return -EINVAL;154 155 if (!acpi_dev_ready_for_enumeration(adev))156 return -ENODEV;157 158 if (acpi_match_device_ids(adev, i2c_acpi_ignored_device_ids) == 0)159 return -ENODEV;160 161 memset(info, 0, sizeof(*info));162 lookup->device_handle = acpi_device_handle(adev);163 164 /* Look up for I2cSerialBus resource */165 INIT_LIST_HEAD(&resource_list);166 ret = acpi_dev_get_resources(adev, &resource_list,167 i2c_acpi_fill_info, lookup);168 acpi_dev_free_resource_list(&resource_list);169 170 if (ret < 0 || !info->addr)171 return -EINVAL;172 173 return 0;174}175 176static int i2c_acpi_add_irq_resource(struct acpi_resource *ares, void *data)177{178 struct i2c_acpi_irq_context *irq_ctx = data;179 struct resource r;180 181 if (irq_ctx->irq > 0)182 return 1;183 184 if (!acpi_dev_resource_interrupt(ares, 0, &r))185 return 1;186 187 irq_ctx->irq = i2c_dev_irq_from_resources(&r, 1);188 irq_ctx->wake_capable = r.flags & IORESOURCE_IRQ_WAKECAPABLE;189 190 return 1; /* No need to add resource to the list */191}192 193/**194 * i2c_acpi_get_irq - get device IRQ number from ACPI195 * @client: Pointer to the I2C client device196 * @wake_capable: Set to true if the IRQ is wake capable197 *198 * Find the IRQ number used by a specific client device.199 *200 * Return: The IRQ number or an error code.201 */202int i2c_acpi_get_irq(struct i2c_client *client, bool *wake_capable)203{204 struct acpi_device *adev = ACPI_COMPANION(&client->dev);205 struct list_head resource_list;206 struct i2c_acpi_irq_context irq_ctx = {207 .irq = -ENOENT,208 };209 int ret;210 211 INIT_LIST_HEAD(&resource_list);212 213 ret = acpi_dev_get_resources(adev, &resource_list,214 i2c_acpi_add_irq_resource, &irq_ctx);215 if (ret < 0)216 return ret;217 218 acpi_dev_free_resource_list(&resource_list);219 220 if (irq_ctx.irq == -ENOENT)221 irq_ctx.irq = acpi_dev_gpio_irq_wake_get(adev, 0, &irq_ctx.wake_capable);222 223 if (irq_ctx.irq < 0)224 return irq_ctx.irq;225 226 if (wake_capable)227 *wake_capable = irq_ctx.wake_capable;228 229 return irq_ctx.irq;230}231 232static int i2c_acpi_get_info(struct acpi_device *adev,233 struct i2c_board_info *info,234 struct i2c_adapter *adapter,235 acpi_handle *adapter_handle)236{237 struct i2c_acpi_lookup lookup;238 int ret;239 240 memset(&lookup, 0, sizeof(lookup));241 lookup.info = info;242 lookup.index = -1;243 244 if (acpi_device_enumerated(adev))245 return -EINVAL;246 247 ret = i2c_acpi_do_lookup(adev, &lookup);248 if (ret)249 return ret;250 251 if (adapter) {252 /* The adapter must match the one in I2cSerialBus() connector */253 if (ACPI_HANDLE(&adapter->dev) != lookup.adapter_handle)254 return -ENODEV;255 } else {256 struct acpi_device *adapter_adev;257 258 /* The adapter must be present */259 adapter_adev = acpi_fetch_acpi_dev(lookup.adapter_handle);260 if (!adapter_adev)261 return -ENODEV;262 if (acpi_bus_get_status(adapter_adev) ||263 !adapter_adev->status.present)264 return -ENODEV;265 }266 267 info->fwnode = acpi_fwnode_handle(adev);268 if (adapter_handle)269 *adapter_handle = lookup.adapter_handle;270 271 acpi_set_modalias(adev, dev_name(&adev->dev), info->type,272 sizeof(info->type));273 274 return 0;275}276 277static void i2c_acpi_register_device(struct i2c_adapter *adapter,278 struct acpi_device *adev,279 struct i2c_board_info *info)280{281 /*282 * Skip registration on boards where the ACPI tables are283 * known to contain bogus I2C devices.284 */285 if (acpi_quirk_skip_i2c_client_enumeration(adev))286 return;287 288 adev->power.flags.ignore_parent = true;289 acpi_device_set_enumerated(adev);290 291 if (IS_ERR(i2c_new_client_device(adapter, info)))292 adev->power.flags.ignore_parent = false;293}294 295static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,296 void *data, void **return_value)297{298 struct i2c_adapter *adapter = data;299 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);300 struct i2c_board_info info;301 302 if (!adev || i2c_acpi_get_info(adev, &info, adapter, NULL))303 return AE_OK;304 305 i2c_acpi_register_device(adapter, adev, &info);306 307 return AE_OK;308}309 310#define I2C_ACPI_MAX_SCAN_DEPTH 32311 312/**313 * i2c_acpi_register_devices - enumerate I2C slave devices behind adapter314 * @adap: pointer to adapter315 *316 * Enumerate all I2C slave devices behind this adapter by walking the ACPI317 * namespace. When a device is found it will be added to the Linux device318 * model and bound to the corresponding ACPI handle.319 */320void i2c_acpi_register_devices(struct i2c_adapter *adap)321{322 struct acpi_device *adev;323 acpi_status status;324 325 if (!has_acpi_companion(&adap->dev))326 return;327 328 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,329 I2C_ACPI_MAX_SCAN_DEPTH,330 i2c_acpi_add_device, NULL,331 adap, NULL);332 if (ACPI_FAILURE(status))333 dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");334 335 if (!adap->dev.parent)336 return;337 338 adev = ACPI_COMPANION(adap->dev.parent);339 if (!adev)340 return;341 342 acpi_dev_clear_dependencies(adev);343}344 345static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {346 /*347 * These Silead touchscreen controllers only work at 400KHz, for348 * some reason they do not work at 100KHz. On some devices the ACPI349 * tables list another device at their bus as only being capable350 * of 100KHz, testing has shown that these other devices work fine351 * at 400KHz (as can be expected of any recent i2c hw) so we force352 * the speed of the bus to 400 KHz if a Silead device is present.353 */354 { "MSSL1680", 0 },355 {}356};357 358static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,359 void *data, void **return_value)360{361 struct i2c_acpi_lookup *lookup = data;362 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);363 364 if (!adev || i2c_acpi_do_lookup(adev, lookup))365 return AE_OK;366 367 if (lookup->search_handle != lookup->adapter_handle)368 return AE_OK;369 370 if (lookup->speed <= lookup->min_speed)371 lookup->min_speed = lookup->speed;372 373 if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)374 lookup->force_speed = I2C_MAX_FAST_MODE_FREQ;375 376 return AE_OK;377}378 379/**380 * i2c_acpi_find_bus_speed - find I2C bus speed from ACPI381 * @dev: The device owning the bus382 *383 * Find the I2C bus speed by walking the ACPI namespace for all I2C slaves384 * devices connected to this bus and use the speed of slowest device.385 *386 * Returns the speed in Hz or zero387 */388u32 i2c_acpi_find_bus_speed(struct device *dev)389{390 struct i2c_acpi_lookup lookup;391 struct i2c_board_info dummy;392 acpi_status status;393 394 if (!has_acpi_companion(dev))395 return 0;396 397 memset(&lookup, 0, sizeof(lookup));398 lookup.search_handle = ACPI_HANDLE(dev);399 lookup.min_speed = UINT_MAX;400 lookup.info = &dummy;401 lookup.index = -1;402 403 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,404 I2C_ACPI_MAX_SCAN_DEPTH,405 i2c_acpi_lookup_speed, NULL,406 &lookup, NULL);407 408 if (ACPI_FAILURE(status)) {409 dev_warn(dev, "unable to find I2C bus speed from ACPI\n");410 return 0;411 }412 413 if (lookup.force_speed) {414 if (lookup.force_speed != lookup.min_speed)415 dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",416 lookup.min_speed, lookup.force_speed);417 return lookup.force_speed;418 } else if (lookup.min_speed != UINT_MAX) {419 return lookup.min_speed;420 } else {421 return 0;422 }423}424EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);425 426struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)427{428 struct i2c_adapter *adapter;429 struct device *dev;430 431 dev = bus_find_device(&i2c_bus_type, NULL, handle, device_match_acpi_handle);432 if (!dev)433 return NULL;434 435 adapter = i2c_verify_adapter(dev);436 if (!adapter)437 put_device(dev);438 439 return adapter;440}441EXPORT_SYMBOL_GPL(i2c_acpi_find_adapter_by_handle);442 443static struct i2c_client *i2c_acpi_find_client_by_adev(struct acpi_device *adev)444{445 return i2c_find_device_by_fwnode(acpi_fwnode_handle(adev));446}447 448static struct i2c_adapter *i2c_acpi_find_adapter_by_adev(struct acpi_device *adev)449{450 return i2c_find_adapter_by_fwnode(acpi_fwnode_handle(adev));451}452 453static int i2c_acpi_notify(struct notifier_block *nb, unsigned long value,454 void *arg)455{456 struct acpi_device *adev = arg;457 struct i2c_board_info info;458 acpi_handle adapter_handle;459 struct i2c_adapter *adapter;460 struct i2c_client *client;461 462 switch (value) {463 case ACPI_RECONFIG_DEVICE_ADD:464 if (i2c_acpi_get_info(adev, &info, NULL, &adapter_handle))465 break;466 467 adapter = i2c_acpi_find_adapter_by_handle(adapter_handle);468 if (!adapter)469 break;470 471 i2c_acpi_register_device(adapter, adev, &info);472 put_device(&adapter->dev);473 break;474 case ACPI_RECONFIG_DEVICE_REMOVE:475 if (!acpi_device_enumerated(adev))476 break;477 478 client = i2c_acpi_find_client_by_adev(adev);479 if (client) {480 i2c_unregister_device(client);481 put_device(&client->dev);482 }483 484 adapter = i2c_acpi_find_adapter_by_adev(adev);485 if (adapter) {486 acpi_unbind_one(&adapter->dev);487 put_device(&adapter->dev);488 }489 490 break;491 }492 493 return NOTIFY_OK;494}495 496struct notifier_block i2c_acpi_notifier = {497 .notifier_call = i2c_acpi_notify,498};499 500/**501 * i2c_acpi_new_device_by_fwnode - Create i2c-client for the Nth I2cSerialBus resource502 * @fwnode: fwnode with the ACPI resources to get the client from503 * @index: Index of ACPI resource to get504 * @info: describes the I2C device; note this is modified (addr gets set)505 * Context: can sleep506 *507 * By default the i2c subsys creates an i2c-client for the first I2cSerialBus508 * resource of an acpi_device, but some acpi_devices have multiple I2cSerialBus509 * resources, in that case this function can be used to create an i2c-client510 * for other I2cSerialBus resources in the Current Resource Settings table.511 *512 * Also see i2c_new_client_device, which this function calls to create the513 * i2c-client.514 *515 * Returns a pointer to the new i2c-client, or error pointer in case of failure.516 * Specifically, -EPROBE_DEFER is returned if the adapter is not found.517 */518struct i2c_client *i2c_acpi_new_device_by_fwnode(struct fwnode_handle *fwnode,519 int index,520 struct i2c_board_info *info)521{522 struct i2c_acpi_lookup lookup;523 struct i2c_adapter *adapter;524 struct acpi_device *adev;525 LIST_HEAD(resource_list);526 int ret;527 528 adev = to_acpi_device_node(fwnode);529 if (!adev)530 return ERR_PTR(-ENODEV);531 532 memset(&lookup, 0, sizeof(lookup));533 lookup.info = info;534 lookup.device_handle = acpi_device_handle(adev);535 lookup.index = index;536 537 ret = acpi_dev_get_resources(adev, &resource_list,538 i2c_acpi_fill_info, &lookup);539 if (ret < 0)540 return ERR_PTR(ret);541 542 acpi_dev_free_resource_list(&resource_list);543 544 if (!info->addr)545 return ERR_PTR(-EADDRNOTAVAIL);546 547 adapter = i2c_acpi_find_adapter_by_handle(lookup.adapter_handle);548 if (!adapter)549 return ERR_PTR(-EPROBE_DEFER);550 551 return i2c_new_client_device(adapter, info);552}553EXPORT_SYMBOL_GPL(i2c_acpi_new_device_by_fwnode);554 555bool i2c_acpi_waive_d0_probe(struct device *dev)556{557 struct i2c_driver *driver = to_i2c_driver(dev->driver);558 struct acpi_device *adev = ACPI_COMPANION(dev);559 560 return driver->flags & I2C_DRV_ACPI_WAIVE_D0_PROBE &&561 adev && adev->power.state_for_enumeration >= adev->power.state;562}563EXPORT_SYMBOL_GPL(i2c_acpi_waive_d0_probe);564 565#ifdef CONFIG_ACPI_I2C_OPREGION566static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,567 u8 cmd, u8 *data, u8 data_len)568{569 570 struct i2c_msg msgs[2];571 int ret;572 u8 *buffer;573 574 buffer = kzalloc(data_len, GFP_KERNEL);575 if (!buffer)576 return AE_NO_MEMORY;577 578 msgs[0].addr = client->addr;579 msgs[0].flags = client->flags;580 msgs[0].len = 1;581 msgs[0].buf = &cmd;582 583 msgs[1].addr = client->addr;584 msgs[1].flags = client->flags | I2C_M_RD;585 msgs[1].len = data_len;586 msgs[1].buf = buffer;587 588 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));589 if (ret < 0) {590 /* Getting a NACK is unfortunately normal with some DSTDs */591 if (ret == -EREMOTEIO)592 dev_dbg(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",593 data_len, client->addr, cmd, ret);594 else595 dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",596 data_len, client->addr, cmd, ret);597 /* 2 transfers must have completed successfully */598 } else if (ret == 2) {599 memcpy(data, buffer, data_len);600 ret = 0;601 } else {602 ret = -EIO;603 }604 605 kfree(buffer);606 return ret;607}608 609static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,610 u8 cmd, u8 *data, u8 data_len)611{612 613 struct i2c_msg msgs[1];614 u8 *buffer;615 int ret = AE_OK;616 617 buffer = kzalloc(data_len + 1, GFP_KERNEL);618 if (!buffer)619 return AE_NO_MEMORY;620 621 buffer[0] = cmd;622 memcpy(buffer + 1, data, data_len);623 624 msgs[0].addr = client->addr;625 msgs[0].flags = client->flags;626 msgs[0].len = data_len + 1;627 msgs[0].buf = buffer;628 629 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));630 631 kfree(buffer);632 633 if (ret < 0) {634 dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);635 return ret;636 }637 638 /* 1 transfer must have completed successfully */639 return (ret == 1) ? 0 : -EIO;640}641 642static acpi_status643i2c_acpi_space_handler(u32 function, acpi_physical_address command,644 u32 bits, u64 *value64,645 void *handler_context, void *region_context)646{647 struct gsb_buffer *gsb = (struct gsb_buffer *)value64;648 struct i2c_acpi_handler_data *data = handler_context;649 struct acpi_connection_info *info = &data->info;650 struct acpi_resource_i2c_serialbus *sb;651 struct i2c_adapter *adapter = data->adapter;652 struct i2c_client *client;653 struct acpi_resource *ares;654 u32 accessor_type = function >> 16;655 u8 action = function & ACPI_IO_MASK;656 acpi_status ret;657 int status;658 659 ret = acpi_buffer_to_resource(info->connection, info->length, &ares);660 if (ACPI_FAILURE(ret))661 return ret;662 663 client = kzalloc(sizeof(*client), GFP_KERNEL);664 if (!client) {665 ret = AE_NO_MEMORY;666 goto err;667 }668 669 if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {670 ret = AE_BAD_PARAMETER;671 goto err;672 }673 674 client->adapter = adapter;675 client->addr = sb->slave_address;676 677 if (sb->access_mode == ACPI_I2C_10BIT_MODE)678 client->flags |= I2C_CLIENT_TEN;679 680 switch (accessor_type) {681 case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:682 if (action == ACPI_READ) {683 status = i2c_smbus_read_byte(client);684 if (status >= 0) {685 gsb->bdata = status;686 status = 0;687 }688 } else {689 status = i2c_smbus_write_byte(client, gsb->bdata);690 }691 break;692 693 case ACPI_GSB_ACCESS_ATTRIB_BYTE:694 if (action == ACPI_READ) {695 status = i2c_smbus_read_byte_data(client, command);696 if (status >= 0) {697 gsb->bdata = status;698 status = 0;699 }700 } else {701 status = i2c_smbus_write_byte_data(client, command,702 gsb->bdata);703 }704 break;705 706 case ACPI_GSB_ACCESS_ATTRIB_WORD:707 if (action == ACPI_READ) {708 status = i2c_smbus_read_word_data(client, command);709 if (status >= 0) {710 gsb->wdata = status;711 status = 0;712 }713 } else {714 status = i2c_smbus_write_word_data(client, command,715 gsb->wdata);716 }717 break;718 719 case ACPI_GSB_ACCESS_ATTRIB_BLOCK:720 if (action == ACPI_READ) {721 status = i2c_smbus_read_block_data(client, command,722 gsb->data);723 if (status >= 0) {724 gsb->len = status;725 status = 0;726 }727 } else {728 status = i2c_smbus_write_block_data(client, command,729 gsb->len, gsb->data);730 }731 break;732 733 case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:734 if (action == ACPI_READ) {735 status = acpi_gsb_i2c_read_bytes(client, command,736 gsb->data, info->access_length);737 } else {738 status = acpi_gsb_i2c_write_bytes(client, command,739 gsb->data, info->access_length);740 }741 break;742 743 default:744 dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",745 accessor_type, client->addr);746 ret = AE_BAD_PARAMETER;747 goto err;748 }749 750 gsb->status = status;751 752 err:753 kfree(client);754 ACPI_FREE(ares);755 return ret;756}757 758 759int i2c_acpi_install_space_handler(struct i2c_adapter *adapter)760{761 acpi_handle handle;762 struct i2c_acpi_handler_data *data;763 acpi_status status;764 765 if (!adapter->dev.parent)766 return -ENODEV;767 768 handle = ACPI_HANDLE(adapter->dev.parent);769 770 if (!handle)771 return -ENODEV;772 773 data = kzalloc(sizeof(struct i2c_acpi_handler_data),774 GFP_KERNEL);775 if (!data)776 return -ENOMEM;777 778 data->adapter = adapter;779 status = acpi_bus_attach_private_data(handle, (void *)data);780 if (ACPI_FAILURE(status)) {781 kfree(data);782 return -ENOMEM;783 }784 785 status = acpi_install_address_space_handler(handle,786 ACPI_ADR_SPACE_GSBUS,787 &i2c_acpi_space_handler,788 NULL,789 data);790 if (ACPI_FAILURE(status)) {791 dev_err(&adapter->dev, "Error installing i2c space handler\n");792 acpi_bus_detach_private_data(handle);793 kfree(data);794 return -ENOMEM;795 }796 797 return 0;798}799 800void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter)801{802 acpi_handle handle;803 struct i2c_acpi_handler_data *data;804 acpi_status status;805 806 if (!adapter->dev.parent)807 return;808 809 handle = ACPI_HANDLE(adapter->dev.parent);810 811 if (!handle)812 return;813 814 acpi_remove_address_space_handler(handle,815 ACPI_ADR_SPACE_GSBUS,816 &i2c_acpi_space_handler);817 818 status = acpi_bus_get_private_data(handle, (void **)&data);819 if (ACPI_SUCCESS(status))820 kfree(data);821 822 acpi_bus_detach_private_data(handle);823}824#endif /* CONFIG_ACPI_I2C_OPREGION */825