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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge4 * Copyright (c) 2013,2014 Uplogix, Inc.5 * David Barksdale <dbarksdale@uplogix.com>6 */7 8/*9 * The Silicon Labs CP2112 chip is a USB HID device which provides an10 * SMBus controller for talking to slave devices and 8 GPIO pins. The11 * host communicates with the CP2112 via raw HID reports.12 *13 * Data Sheet:14 *   https://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf15 * Programming Interface Specification:16 *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf17 */18 19#include <linux/bitops.h>20#include <linux/gpio/driver.h>21#include <linux/hid.h>22#include <linux/hidraw.h>23#include <linux/i2c.h>24#include <linux/module.h>25#include <linux/nls.h>26#include <linux/string_choices.h>27#include <linux/usb/ch9.h>28#include "hid-ids.h"29 30#define CP2112_REPORT_MAX_LENGTH		6431#define CP2112_GPIO_CONFIG_LENGTH		532#define CP2112_GPIO_GET_LENGTH			233#define CP2112_GPIO_SET_LENGTH			334#define CP2112_GPIO_MAX_GPIO			835#define CP2112_GPIO_ALL_GPIO_MASK		GENMASK(7, 0)36 37enum {38	CP2112_GPIO_CONFIG		= 0x02,39	CP2112_GPIO_GET			= 0x03,40	CP2112_GPIO_SET			= 0x04,41	CP2112_GET_VERSION_INFO		= 0x05,42	CP2112_SMBUS_CONFIG		= 0x06,43	CP2112_DATA_READ_REQUEST	= 0x10,44	CP2112_DATA_WRITE_READ_REQUEST	= 0x11,45	CP2112_DATA_READ_FORCE_SEND	= 0x12,46	CP2112_DATA_READ_RESPONSE	= 0x13,47	CP2112_DATA_WRITE_REQUEST	= 0x14,48	CP2112_TRANSFER_STATUS_REQUEST	= 0x15,49	CP2112_TRANSFER_STATUS_RESPONSE	= 0x16,50	CP2112_CANCEL_TRANSFER		= 0x17,51	CP2112_LOCK_BYTE		= 0x20,52	CP2112_USB_CONFIG		= 0x21,53	CP2112_MANUFACTURER_STRING	= 0x22,54	CP2112_PRODUCT_STRING		= 0x23,55	CP2112_SERIAL_STRING		= 0x24,56};57 58enum {59	STATUS0_IDLE		= 0x00,60	STATUS0_BUSY		= 0x01,61	STATUS0_COMPLETE	= 0x02,62	STATUS0_ERROR		= 0x03,63};64 65enum {66	STATUS1_TIMEOUT_NACK		= 0x00,67	STATUS1_TIMEOUT_BUS		= 0x01,68	STATUS1_ARBITRATION_LOST	= 0x02,69	STATUS1_READ_INCOMPLETE		= 0x03,70	STATUS1_WRITE_INCOMPLETE	= 0x04,71	STATUS1_SUCCESS			= 0x05,72};73 74struct cp2112_smbus_config_report {75	u8 report;		/* CP2112_SMBUS_CONFIG */76	__be32 clock_speed;	/* Hz */77	u8 device_address;	/* Stored in the upper 7 bits */78	u8 auto_send_read;	/* 1 = enabled, 0 = disabled */79	__be16 write_timeout;	/* ms, 0 = no timeout */80	__be16 read_timeout;	/* ms, 0 = no timeout */81	u8 scl_low_timeout;	/* 1 = enabled, 0 = disabled */82	__be16 retry_time;	/* # of retries, 0 = no limit */83} __packed;84 85struct cp2112_usb_config_report {86	u8 report;	/* CP2112_USB_CONFIG */87	__le16 vid;	/* Vendor ID */88	__le16 pid;	/* Product ID */89	u8 max_power;	/* Power requested in 2mA units */90	u8 power_mode;	/* 0x00 = bus powered91			   0x01 = self powered & regulator off92			   0x02 = self powered & regulator on */93	u8 release_major;94	u8 release_minor;95	u8 mask;	/* What fields to program */96} __packed;97 98struct cp2112_read_req_report {99	u8 report;	/* CP2112_DATA_READ_REQUEST */100	u8 slave_address;101	__be16 length;102} __packed;103 104struct cp2112_write_read_req_report {105	u8 report;	/* CP2112_DATA_WRITE_READ_REQUEST */106	u8 slave_address;107	__be16 length;108	u8 target_address_length;109	u8 target_address[16];110} __packed;111 112struct cp2112_write_req_report {113	u8 report;	/* CP2112_DATA_WRITE_REQUEST */114	u8 slave_address;115	u8 length;116	u8 data[61];117} __packed;118 119struct cp2112_force_read_report {120	u8 report;	/* CP2112_DATA_READ_FORCE_SEND */121	__be16 length;122} __packed;123 124struct cp2112_xfer_status_report {125	u8 report;	/* CP2112_TRANSFER_STATUS_RESPONSE */126	u8 status0;	/* STATUS0_* */127	u8 status1;	/* STATUS1_* */128	__be16 retries;129	__be16 length;130} __packed;131 132struct cp2112_string_report {133	u8 dummy;		/* force .string to be aligned */134	struct_group_attr(contents, __packed,135		u8 report;		/* CP2112_*_STRING */136		u8 length;		/* length in bytes of everything after .report */137		u8 type;		/* USB_DT_STRING */138		wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */139	);140} __packed;141 142/* Number of times to request transfer status before giving up waiting for a143   transfer to complete. This may need to be changed if SMBUS clock, retries,144   or read/write/scl_low timeout settings are changed. */145static const int XFER_STATUS_RETRIES = 10;146 147/* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or148   CP2112_TRANSFER_STATUS_RESPONSE. */149static const int RESPONSE_TIMEOUT = 50;150 151static const struct hid_device_id cp2112_devices[] = {152	{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },153	{ }154};155MODULE_DEVICE_TABLE(hid, cp2112_devices);156 157struct cp2112_device {158	struct i2c_adapter adap;159	struct hid_device *hdev;160	wait_queue_head_t wait;161	u8 read_data[61];162	u8 read_length;163	u8 hwversion;164	int xfer_status;165	atomic_t read_avail;166	atomic_t xfer_avail;167	struct gpio_chip gc;168	u8 *in_out_buffer;169	struct mutex lock;170 171	bool gpio_poll;172	struct delayed_work gpio_poll_worker;173	unsigned long irq_mask;174	u8 gpio_prev_state;175};176 177static int gpio_push_pull = CP2112_GPIO_ALL_GPIO_MASK;178module_param(gpio_push_pull, int, 0644);179MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");180 181static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)182{183	struct cp2112_device *dev = gpiochip_get_data(chip);184	struct hid_device *hdev = dev->hdev;185	u8 *buf = dev->in_out_buffer;186	int ret;187 188	mutex_lock(&dev->lock);189 190	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,191				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,192				 HID_REQ_GET_REPORT);193	if (ret != CP2112_GPIO_CONFIG_LENGTH) {194		hid_err(hdev, "error requesting GPIO config: %d\n", ret);195		if (ret >= 0)196			ret = -EIO;197		goto exit;198	}199 200	buf[1] &= ~BIT(offset);201	buf[2] = gpio_push_pull;202 203	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,204				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,205				 HID_REQ_SET_REPORT);206	if (ret != CP2112_GPIO_CONFIG_LENGTH) {207		hid_err(hdev, "error setting GPIO config: %d\n", ret);208		if (ret >= 0)209			ret = -EIO;210		goto exit;211	}212 213	ret = 0;214 215exit:216	mutex_unlock(&dev->lock);217	return ret;218}219 220static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)221{222	struct cp2112_device *dev = gpiochip_get_data(chip);223	struct hid_device *hdev = dev->hdev;224	u8 *buf = dev->in_out_buffer;225	int ret;226 227	mutex_lock(&dev->lock);228 229	buf[0] = CP2112_GPIO_SET;230	buf[1] = value ? CP2112_GPIO_ALL_GPIO_MASK : 0;231	buf[2] = BIT(offset);232 233	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,234				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,235				 HID_REQ_SET_REPORT);236	if (ret < 0)237		hid_err(hdev, "error setting GPIO values: %d\n", ret);238 239	mutex_unlock(&dev->lock);240}241 242static int cp2112_gpio_get_all(struct gpio_chip *chip)243{244	struct cp2112_device *dev = gpiochip_get_data(chip);245	struct hid_device *hdev = dev->hdev;246	u8 *buf = dev->in_out_buffer;247	int ret;248 249	mutex_lock(&dev->lock);250 251	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,252				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,253				 HID_REQ_GET_REPORT);254	if (ret != CP2112_GPIO_GET_LENGTH) {255		hid_err(hdev, "error requesting GPIO values: %d\n", ret);256		ret = ret < 0 ? ret : -EIO;257		goto exit;258	}259 260	ret = buf[1];261 262exit:263	mutex_unlock(&dev->lock);264 265	return ret;266}267 268static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)269{270	int ret;271 272	ret = cp2112_gpio_get_all(chip);273	if (ret < 0)274		return ret;275 276	return (ret >> offset) & 1;277}278 279static int cp2112_gpio_direction_output(struct gpio_chip *chip,280					unsigned offset, int value)281{282	struct cp2112_device *dev = gpiochip_get_data(chip);283	struct hid_device *hdev = dev->hdev;284	u8 *buf = dev->in_out_buffer;285	int ret;286 287	mutex_lock(&dev->lock);288 289	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,290				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,291				 HID_REQ_GET_REPORT);292	if (ret != CP2112_GPIO_CONFIG_LENGTH) {293		hid_err(hdev, "error requesting GPIO config: %d\n", ret);294		goto fail;295	}296 297	buf[1] |= 1 << offset;298	buf[2] = gpio_push_pull;299 300	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,301				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,302				 HID_REQ_SET_REPORT);303	if (ret < 0) {304		hid_err(hdev, "error setting GPIO config: %d\n", ret);305		goto fail;306	}307 308	mutex_unlock(&dev->lock);309 310	/*311	 * Set gpio value when output direction is already set,312	 * as specified in AN495, Rev. 0.2, cpt. 4.4313	 */314	cp2112_gpio_set(chip, offset, value);315 316	return 0;317 318fail:319	mutex_unlock(&dev->lock);320	return ret < 0 ? ret : -EIO;321}322 323static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,324			  u8 *data, size_t count, unsigned char report_type)325{326	u8 *buf;327	int ret;328 329	buf = kmalloc(count, GFP_KERNEL);330	if (!buf)331		return -ENOMEM;332 333	ret = hid_hw_raw_request(hdev, report_number, buf, count,334				       report_type, HID_REQ_GET_REPORT);335	memcpy(data, buf, count);336	kfree(buf);337	return ret;338}339 340static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,341			     unsigned char report_type)342{343	u8 *buf;344	int ret;345 346	buf = kmemdup(data, count, GFP_KERNEL);347	if (!buf)348		return -ENOMEM;349 350	if (report_type == HID_OUTPUT_REPORT)351		ret = hid_hw_output_report(hdev, buf, count);352	else353		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,354				HID_REQ_SET_REPORT);355 356	kfree(buf);357	return ret;358}359 360static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)361{362	int ret = 0;363 364	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a365	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to366	 * come in cp2112_raw_event or timeout. There will only be one of these367	 * in flight at any one time. The timeout is extremely large and is a368	 * last resort if the CP2112 has died. If we do timeout we don't expect369	 * to receive the response which would cause data races, it's not like370	 * we can do anything about it anyway.371	 */372	ret = wait_event_interruptible_timeout(dev->wait,373		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));374	if (-ERESTARTSYS == ret)375		return ret;376	if (!ret)377		return -ETIMEDOUT;378 379	atomic_set(avail, 0);380	return 0;381}382 383static int cp2112_xfer_status(struct cp2112_device *dev)384{385	struct hid_device *hdev = dev->hdev;386	u8 buf[2];387	int ret;388 389	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;390	buf[1] = 0x01;391	atomic_set(&dev->xfer_avail, 0);392 393	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);394	if (ret < 0) {395		hid_warn(hdev, "Error requesting status: %d\n", ret);396		return ret;397	}398 399	ret = cp2112_wait(dev, &dev->xfer_avail);400	if (ret)401		return ret;402 403	return dev->xfer_status;404}405 406static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)407{408	struct hid_device *hdev = dev->hdev;409	struct cp2112_force_read_report report;410	int ret;411 412	if (size > sizeof(dev->read_data))413		size = sizeof(dev->read_data);414	report.report = CP2112_DATA_READ_FORCE_SEND;415	report.length = cpu_to_be16(size);416 417	atomic_set(&dev->read_avail, 0);418 419	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),420				HID_OUTPUT_REPORT);421	if (ret < 0) {422		hid_warn(hdev, "Error requesting data: %d\n", ret);423		return ret;424	}425 426	ret = cp2112_wait(dev, &dev->read_avail);427	if (ret)428		return ret;429 430	hid_dbg(hdev, "read %d of %zd bytes requested\n",431		dev->read_length, size);432 433	if (size > dev->read_length)434		size = dev->read_length;435 436	memcpy(data, dev->read_data, size);437	return dev->read_length;438}439 440static int cp2112_read_req(void *buf, u8 slave_address, u16 length)441{442	struct cp2112_read_req_report *report = buf;443 444	if (length < 1 || length > 512)445		return -EINVAL;446 447	report->report = CP2112_DATA_READ_REQUEST;448	report->slave_address = slave_address << 1;449	report->length = cpu_to_be16(length);450	return sizeof(*report);451}452 453static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,454				 u8 command, u8 *data, u8 data_length)455{456	struct cp2112_write_read_req_report *report = buf;457 458	if (length < 1 || length > 512459	    || data_length > sizeof(report->target_address) - 1)460		return -EINVAL;461 462	report->report = CP2112_DATA_WRITE_READ_REQUEST;463	report->slave_address = slave_address << 1;464	report->length = cpu_to_be16(length);465	report->target_address_length = data_length + 1;466	report->target_address[0] = command;467	memcpy(&report->target_address[1], data, data_length);468	return data_length + 6;469}470 471static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,472			    u8 data_length)473{474	struct cp2112_write_req_report *report = buf;475 476	if (data_length > sizeof(report->data) - 1)477		return -EINVAL;478 479	report->report = CP2112_DATA_WRITE_REQUEST;480	report->slave_address = slave_address << 1;481	report->length = data_length + 1;482	report->data[0] = command;483	memcpy(&report->data[1], data, data_length);484	return data_length + 4;485}486 487static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,488				u8 data_length)489{490	struct cp2112_write_req_report *report = buf;491 492	if (data_length > sizeof(report->data))493		return -EINVAL;494 495	report->report = CP2112_DATA_WRITE_REQUEST;496	report->slave_address = slave_address << 1;497	report->length = data_length;498	memcpy(report->data, data, data_length);499	return data_length + 3;500}501 502static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,503				     u8 *addr, int addr_length,504				     int read_length)505{506	struct cp2112_write_read_req_report *report = buf;507 508	if (read_length < 1 || read_length > 512 ||509	    addr_length > sizeof(report->target_address))510		return -EINVAL;511 512	report->report = CP2112_DATA_WRITE_READ_REQUEST;513	report->slave_address = slave_address << 1;514	report->length = cpu_to_be16(read_length);515	report->target_address_length = addr_length;516	memcpy(report->target_address, addr, addr_length);517	return addr_length + 5;518}519 520static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,521			   int num)522{523	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;524	struct hid_device *hdev = dev->hdev;525	u8 buf[64];526	ssize_t count;527	ssize_t read_length = 0;528	u8 *read_buf = NULL;529	unsigned int retries;530	int ret;531 532	hid_dbg(hdev, "I2C %d messages\n", num);533 534	if (num == 1) {535		hid_dbg(hdev, "I2C %s %#04x len %d\n",536			str_read_write(msgs->flags & I2C_M_RD), msgs->addr, msgs->len);537		if (msgs->flags & I2C_M_RD) {538			read_length = msgs->len;539			read_buf = msgs->buf;540			count = cp2112_read_req(buf, msgs->addr, msgs->len);541		} else {542			count = cp2112_i2c_write_req(buf, msgs->addr,543						     msgs->buf, msgs->len);544		}545		if (count < 0)546			return count;547	} else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */548		   num == 2 &&549		   msgs[0].addr == msgs[1].addr &&550		   !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {551		hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",552			msgs[0].addr, msgs[0].len, msgs[1].len);553		read_length = msgs[1].len;554		read_buf = msgs[1].buf;555		count = cp2112_i2c_write_read_req(buf, msgs[0].addr,556				msgs[0].buf, msgs[0].len, msgs[1].len);557		if (count < 0)558			return count;559	} else {560		hid_err(hdev,561			"Multi-message I2C transactions not supported\n");562		return -EOPNOTSUPP;563	}564 565	ret = hid_hw_power(hdev, PM_HINT_FULLON);566	if (ret < 0) {567		hid_err(hdev, "power management error: %d\n", ret);568		return ret;569	}570 571	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);572	if (ret < 0) {573		hid_warn(hdev, "Error starting transaction: %d\n", ret);574		goto power_normal;575	}576 577	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {578		ret = cp2112_xfer_status(dev);579		if (-EBUSY == ret)580			continue;581		if (ret < 0)582			goto power_normal;583		break;584	}585 586	if (XFER_STATUS_RETRIES <= retries) {587		hid_warn(hdev, "Transfer timed out, cancelling.\n");588		buf[0] = CP2112_CANCEL_TRANSFER;589		buf[1] = 0x01;590 591		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);592		if (ret < 0)593			hid_warn(hdev, "Error cancelling transaction: %d\n",594				 ret);595 596		ret = -ETIMEDOUT;597		goto power_normal;598	}599 600	for (count = 0; count < read_length;) {601		ret = cp2112_read(dev, read_buf + count, read_length - count);602		if (ret < 0)603			goto power_normal;604		if (ret == 0) {605			hid_err(hdev, "read returned 0\n");606			ret = -EIO;607			goto power_normal;608		}609		count += ret;610		if (count > read_length) {611			/*612			 * The hardware returned too much data.613			 * This is mostly harmless because cp2112_read()614			 * has a limit check so didn't overrun our615			 * buffer.  Nevertheless, we return an error616			 * because something is seriously wrong and617			 * it shouldn't go unnoticed.618			 */619			hid_err(hdev, "long read: %d > %zd\n",620				ret, read_length - count + ret);621			ret = -EIO;622			goto power_normal;623		}624	}625 626	/* return the number of transferred messages */627	ret = num;628 629power_normal:630	hid_hw_power(hdev, PM_HINT_NORMAL);631	hid_dbg(hdev, "I2C transfer finished: %d\n", ret);632	return ret;633}634 635static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,636		       unsigned short flags, char read_write, u8 command,637		       int size, union i2c_smbus_data *data)638{639	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;640	struct hid_device *hdev = dev->hdev;641	u8 buf[64];642	__le16 word;643	ssize_t count;644	size_t read_length = 0;645	unsigned int retries;646	int ret;647 648	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",649		str_write_read(read_write == I2C_SMBUS_WRITE),650		addr, flags, command, size);651 652	switch (size) {653	case I2C_SMBUS_BYTE:654		read_length = 1;655 656		if (I2C_SMBUS_READ == read_write)657			count = cp2112_read_req(buf, addr, read_length);658		else659			count = cp2112_write_req(buf, addr, command, NULL,660						 0);661		break;662	case I2C_SMBUS_BYTE_DATA:663		read_length = 1;664 665		if (I2C_SMBUS_READ == read_write)666			count = cp2112_write_read_req(buf, addr, read_length,667						      command, NULL, 0);668		else669			count = cp2112_write_req(buf, addr, command,670						 &data->byte, 1);671		break;672	case I2C_SMBUS_WORD_DATA:673		read_length = 2;674		word = cpu_to_le16(data->word);675 676		if (I2C_SMBUS_READ == read_write)677			count = cp2112_write_read_req(buf, addr, read_length,678						      command, NULL, 0);679		else680			count = cp2112_write_req(buf, addr, command,681						 (u8 *)&word, 2);682		break;683	case I2C_SMBUS_PROC_CALL:684		size = I2C_SMBUS_WORD_DATA;685		read_write = I2C_SMBUS_READ;686		read_length = 2;687		word = cpu_to_le16(data->word);688 689		count = cp2112_write_read_req(buf, addr, read_length, command,690					      (u8 *)&word, 2);691		break;692	case I2C_SMBUS_I2C_BLOCK_DATA:693		if (read_write == I2C_SMBUS_READ) {694			read_length = data->block[0];695			count = cp2112_write_read_req(buf, addr, read_length,696						      command, NULL, 0);697		} else {698			count = cp2112_write_req(buf, addr, command,699						 data->block + 1,700						 data->block[0]);701		}702		break;703	case I2C_SMBUS_BLOCK_DATA:704		if (I2C_SMBUS_READ == read_write) {705			count = cp2112_write_read_req(buf, addr,706						      I2C_SMBUS_BLOCK_MAX,707						      command, NULL, 0);708		} else {709			count = cp2112_write_req(buf, addr, command,710						 data->block,711						 data->block[0] + 1);712		}713		break;714	case I2C_SMBUS_BLOCK_PROC_CALL:715		size = I2C_SMBUS_BLOCK_DATA;716		read_write = I2C_SMBUS_READ;717 718		count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,719					      command, data->block,720					      data->block[0] + 1);721		break;722	default:723		hid_warn(hdev, "Unsupported transaction %d\n", size);724		return -EOPNOTSUPP;725	}726 727	if (count < 0)728		return count;729 730	ret = hid_hw_power(hdev, PM_HINT_FULLON);731	if (ret < 0) {732		hid_err(hdev, "power management error: %d\n", ret);733		return ret;734	}735 736	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);737	if (ret < 0) {738		hid_warn(hdev, "Error starting transaction: %d\n", ret);739		goto power_normal;740	}741 742	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {743		ret = cp2112_xfer_status(dev);744		if (-EBUSY == ret)745			continue;746		if (ret < 0)747			goto power_normal;748		break;749	}750 751	if (XFER_STATUS_RETRIES <= retries) {752		hid_warn(hdev, "Transfer timed out, cancelling.\n");753		buf[0] = CP2112_CANCEL_TRANSFER;754		buf[1] = 0x01;755 756		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);757		if (ret < 0)758			hid_warn(hdev, "Error cancelling transaction: %d\n",759				 ret);760 761		ret = -ETIMEDOUT;762		goto power_normal;763	}764 765	if (I2C_SMBUS_WRITE == read_write) {766		ret = 0;767		goto power_normal;768	}769 770	if (I2C_SMBUS_BLOCK_DATA == size)771		read_length = ret;772 773	ret = cp2112_read(dev, buf, read_length);774	if (ret < 0)775		goto power_normal;776	if (ret != read_length) {777		hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);778		ret = -EIO;779		goto power_normal;780	}781 782	switch (size) {783	case I2C_SMBUS_BYTE:784	case I2C_SMBUS_BYTE_DATA:785		data->byte = buf[0];786		break;787	case I2C_SMBUS_WORD_DATA:788		data->word = le16_to_cpup((__le16 *)buf);789		break;790	case I2C_SMBUS_I2C_BLOCK_DATA:791		if (read_length > I2C_SMBUS_BLOCK_MAX) {792			ret = -EINVAL;793			goto power_normal;794		}795 796		memcpy(data->block + 1, buf, read_length);797		break;798	case I2C_SMBUS_BLOCK_DATA:799		if (read_length > I2C_SMBUS_BLOCK_MAX) {800			ret = -EPROTO;801			goto power_normal;802		}803 804		memcpy(data->block, buf, read_length);805		break;806	}807 808	ret = 0;809power_normal:810	hid_hw_power(hdev, PM_HINT_NORMAL);811	hid_dbg(hdev, "transfer finished: %d\n", ret);812	return ret;813}814 815static u32 cp2112_functionality(struct i2c_adapter *adap)816{817	return I2C_FUNC_I2C |818		I2C_FUNC_SMBUS_BYTE |819		I2C_FUNC_SMBUS_BYTE_DATA |820		I2C_FUNC_SMBUS_WORD_DATA |821		I2C_FUNC_SMBUS_BLOCK_DATA |822		I2C_FUNC_SMBUS_I2C_BLOCK |823		I2C_FUNC_SMBUS_PROC_CALL |824		I2C_FUNC_SMBUS_BLOCK_PROC_CALL;825}826 827static const struct i2c_algorithm smbus_algorithm = {828	.master_xfer	= cp2112_i2c_xfer,829	.smbus_xfer	= cp2112_xfer,830	.functionality	= cp2112_functionality,831};832 833static int cp2112_get_usb_config(struct hid_device *hdev,834				 struct cp2112_usb_config_report *cfg)835{836	int ret;837 838	ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),839			     HID_FEATURE_REPORT);840	if (ret != sizeof(*cfg)) {841		hid_err(hdev, "error reading usb config: %d\n", ret);842		if (ret < 0)843			return ret;844		return -EIO;845	}846 847	return 0;848}849 850static int cp2112_set_usb_config(struct hid_device *hdev,851				 struct cp2112_usb_config_report *cfg)852{853	int ret;854 855	BUG_ON(cfg->report != CP2112_USB_CONFIG);856 857	ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),858				HID_FEATURE_REPORT);859	if (ret != sizeof(*cfg)) {860		hid_err(hdev, "error writing usb config: %d\n", ret);861		if (ret < 0)862			return ret;863		return -EIO;864	}865 866	return 0;867}868 869static void chmod_sysfs_attrs(struct hid_device *hdev);870 871#define CP2112_CONFIG_ATTR(name, store, format, ...) \872static ssize_t name##_store(struct device *kdev, \873			    struct device_attribute *attr, const char *buf, \874			    size_t count) \875{ \876	struct hid_device *hdev = to_hid_device(kdev); \877	struct cp2112_usb_config_report cfg; \878	int ret = cp2112_get_usb_config(hdev, &cfg); \879	if (ret) \880		return ret; \881	store; \882	ret = cp2112_set_usb_config(hdev, &cfg); \883	if (ret) \884		return ret; \885	chmod_sysfs_attrs(hdev); \886	return count; \887} \888static ssize_t name##_show(struct device *kdev, \889			   struct device_attribute *attr, char *buf) \890{ \891	struct hid_device *hdev = to_hid_device(kdev); \892	struct cp2112_usb_config_report cfg; \893	int ret = cp2112_get_usb_config(hdev, &cfg); \894	if (ret) \895		return ret; \896	return sysfs_emit(buf, format, ##__VA_ARGS__); \897} \898static DEVICE_ATTR_RW(name);899 900CP2112_CONFIG_ATTR(vendor_id, ({901	u16 vid;902 903	if (sscanf(buf, "%hi", &vid) != 1)904		return -EINVAL;905 906	cfg.vid = cpu_to_le16(vid);907	cfg.mask = 0x01;908}), "0x%04x\n", le16_to_cpu(cfg.vid));909 910CP2112_CONFIG_ATTR(product_id, ({911	u16 pid;912 913	if (sscanf(buf, "%hi", &pid) != 1)914		return -EINVAL;915 916	cfg.pid = cpu_to_le16(pid);917	cfg.mask = 0x02;918}), "0x%04x\n", le16_to_cpu(cfg.pid));919 920CP2112_CONFIG_ATTR(max_power, ({921	int mA;922 923	if (sscanf(buf, "%i", &mA) != 1)924		return -EINVAL;925 926	cfg.max_power = (mA + 1) / 2;927	cfg.mask = 0x04;928}), "%u mA\n", cfg.max_power * 2);929 930CP2112_CONFIG_ATTR(power_mode, ({931	if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)932		return -EINVAL;933 934	cfg.mask = 0x08;935}), "%u\n", cfg.power_mode);936 937CP2112_CONFIG_ATTR(release_version, ({938	if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)939	    != 2)940		return -EINVAL;941 942	cfg.mask = 0x10;943}), "%u.%u\n", cfg.release_major, cfg.release_minor);944 945#undef CP2112_CONFIG_ATTR946 947static ssize_t pstr_store(struct device *kdev, struct device_attribute *kattr,948			  const char *buf, size_t count, int number)949{950	struct hid_device *hdev = to_hid_device(kdev);951	struct cp2112_string_report report;952	int ret;953 954	memset(&report, 0, sizeof(report));955 956	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,957			      report.string, ARRAY_SIZE(report.string));958	report.report = number;959	report.length = ret * sizeof(report.string[0]) + 2;960	report.type = USB_DT_STRING;961 962	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,963				HID_FEATURE_REPORT);964	if (ret != report.length + 1) {965		hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,966			ret);967		if (ret < 0)968			return ret;969		return -EIO;970	}971 972	chmod_sysfs_attrs(hdev);973	return count;974}975 976static ssize_t pstr_show(struct device *kdev, struct device_attribute *kattr,977			 char *buf, int number)978{979	struct hid_device *hdev = to_hid_device(kdev);980	struct cp2112_string_report report;981	u8 length;982	int ret;983 984	ret = cp2112_hid_get(hdev, number, (u8 *)&report.contents,985			     sizeof(report.contents), HID_FEATURE_REPORT);986	if (ret < 3) {987		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,988			ret);989		if (ret < 0)990			return ret;991		return -EIO;992	}993 994	if (report.length < 2) {995		hid_err(hdev, "invalid %s string length: %d\n",996			kattr->attr.name, report.length);997		return -EIO;998	}999 1000	length = report.length > ret - 1 ? ret - 1 : report.length;1001	length = (length - 2) / sizeof(report.string[0]);1002	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,1003			      PAGE_SIZE - 1);1004	buf[ret++] = '\n';1005	return ret;1006}1007 1008#define CP2112_PSTR_ATTR(name, _report) \1009static ssize_t name##_store(struct device *kdev, struct device_attribute *kattr, \1010			    const char *buf, size_t count) \1011{ \1012	return pstr_store(kdev, kattr, buf, count, _report); \1013} \1014static ssize_t name##_show(struct device *kdev, struct device_attribute *kattr, char *buf) \1015{ \1016	return pstr_show(kdev, kattr, buf, _report); \1017} \1018static DEVICE_ATTR_RW(name);1019 1020CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);1021CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);1022CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);1023 1024#undef CP2112_PSTR_ATTR1025 1026static const struct attribute_group cp2112_attr_group = {1027	.attrs = (struct attribute *[]){1028		&dev_attr_vendor_id.attr,1029		&dev_attr_product_id.attr,1030		&dev_attr_max_power.attr,1031		&dev_attr_power_mode.attr,1032		&dev_attr_release_version.attr,1033		&dev_attr_manufacturer.attr,1034		&dev_attr_product.attr,1035		&dev_attr_serial.attr,1036		NULL1037	}1038};1039 1040/* Chmoding our sysfs attributes is simply a way to expose which fields in the1041 * PROM have already been programmed. We do not depend on this preventing1042 * writing to these attributes since the CP2112 will simply ignore writes to1043 * already-programmed fields. This is why there is no sense in fixing this1044 * racy behaviour.1045 */1046static void chmod_sysfs_attrs(struct hid_device *hdev)1047{1048	struct attribute **attr;1049	u8 buf[2];1050	int ret;1051 1052	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),1053			     HID_FEATURE_REPORT);1054	if (ret != sizeof(buf)) {1055		hid_err(hdev, "error reading lock byte: %d\n", ret);1056		return;1057	}1058 1059	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {1060		umode_t mode = (buf[1] & 1) ? 0644 : 0444;1061		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);1062		if (ret < 0)1063			hid_err(hdev, "error chmoding sysfs file %s\n",1064				(*attr)->name);1065		buf[1] >>= 1;1066	}1067}1068 1069static void cp2112_gpio_irq_ack(struct irq_data *d)1070{1071}1072 1073static void cp2112_gpio_irq_mask(struct irq_data *d)1074{1075	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1076	struct cp2112_device *dev = gpiochip_get_data(gc);1077	irq_hw_number_t hwirq = irqd_to_hwirq(d);1078 1079	__clear_bit(hwirq, &dev->irq_mask);1080	gpiochip_disable_irq(gc, hwirq);1081}1082 1083static void cp2112_gpio_irq_unmask(struct irq_data *d)1084{1085	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1086	struct cp2112_device *dev = gpiochip_get_data(gc);1087	irq_hw_number_t hwirq = irqd_to_hwirq(d);1088 1089	gpiochip_enable_irq(gc, hwirq);1090	__set_bit(hwirq, &dev->irq_mask);1091}1092 1093static void cp2112_gpio_poll_callback(struct work_struct *work)1094{1095	struct cp2112_device *dev = container_of(work, struct cp2112_device,1096						 gpio_poll_worker.work);1097	u8 gpio_mask;1098	u32 irq_type;1099	int irq, virq, ret;1100 1101	ret = cp2112_gpio_get_all(&dev->gc);1102	if (ret == -ENODEV) /* the hardware has been disconnected */1103		return;1104	if (ret < 0)1105		goto exit;1106 1107	gpio_mask = ret;1108	for_each_set_bit(virq, &dev->irq_mask, CP2112_GPIO_MAX_GPIO) {1109		irq = irq_find_mapping(dev->gc.irq.domain, virq);1110		if (!irq)1111			continue;1112 1113		irq_type = irq_get_trigger_type(irq);1114		if (!irq_type)1115			continue;1116 1117		if (gpio_mask & BIT(virq)) {1118			/* Level High */1119 1120			if (irq_type & IRQ_TYPE_LEVEL_HIGH)1121				handle_nested_irq(irq);1122 1123			if ((irq_type & IRQ_TYPE_EDGE_RISING) &&1124			    !(dev->gpio_prev_state & BIT(virq)))1125				handle_nested_irq(irq);1126		} else {1127			/* Level Low */1128 1129			if (irq_type & IRQ_TYPE_LEVEL_LOW)1130				handle_nested_irq(irq);1131 1132			if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&1133			    (dev->gpio_prev_state & BIT(virq)))1134				handle_nested_irq(irq);1135		}1136	}1137 1138	dev->gpio_prev_state = gpio_mask;1139 1140exit:1141	if (dev->gpio_poll)1142		schedule_delayed_work(&dev->gpio_poll_worker, 10);1143}1144 1145 1146static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)1147{1148	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1149	struct cp2112_device *dev = gpiochip_get_data(gc);1150 1151	if (!dev->gpio_poll) {1152		dev->gpio_poll = true;1153		schedule_delayed_work(&dev->gpio_poll_worker, 0);1154	}1155 1156	cp2112_gpio_irq_unmask(d);1157	return 0;1158}1159 1160static void cp2112_gpio_irq_shutdown(struct irq_data *d)1161{1162	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);1163	struct cp2112_device *dev = gpiochip_get_data(gc);1164 1165	cp2112_gpio_irq_mask(d);1166 1167	if (!dev->irq_mask) {1168		dev->gpio_poll = false;1169		cancel_delayed_work_sync(&dev->gpio_poll_worker);1170	}1171}1172 1173static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)1174{1175	return 0;1176}1177 1178static const struct irq_chip cp2112_gpio_irqchip = {1179	.name = "cp2112-gpio",1180	.irq_startup = cp2112_gpio_irq_startup,1181	.irq_shutdown = cp2112_gpio_irq_shutdown,1182	.irq_ack = cp2112_gpio_irq_ack,1183	.irq_mask = cp2112_gpio_irq_mask,1184	.irq_unmask = cp2112_gpio_irq_unmask,1185	.irq_set_type = cp2112_gpio_irq_type,1186	.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,1187	GPIOCHIP_IRQ_RESOURCE_HELPERS,1188};1189 1190static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)1191{1192	struct cp2112_device *dev;1193	u8 buf[3];1194	struct cp2112_smbus_config_report config;1195	struct gpio_irq_chip *girq;1196	int ret;1197 1198	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);1199	if (!dev)1200		return -ENOMEM;1201 1202	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,1203					  GFP_KERNEL);1204	if (!dev->in_out_buffer)1205		return -ENOMEM;1206 1207	mutex_init(&dev->lock);1208 1209	ret = hid_parse(hdev);1210	if (ret) {1211		hid_err(hdev, "parse failed\n");1212		return ret;1213	}1214 1215	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);1216	if (ret) {1217		hid_err(hdev, "hw start failed\n");1218		return ret;1219	}1220 1221	ret = hid_hw_open(hdev);1222	if (ret) {1223		hid_err(hdev, "hw open failed\n");1224		goto err_hid_stop;1225	}1226 1227	ret = hid_hw_power(hdev, PM_HINT_FULLON);1228	if (ret < 0) {1229		hid_err(hdev, "power management error: %d\n", ret);1230		goto err_hid_close;1231	}1232 1233	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),1234			     HID_FEATURE_REPORT);1235	if (ret != sizeof(buf)) {1236		hid_err(hdev, "error requesting version\n");1237		if (ret >= 0)1238			ret = -EIO;1239		goto err_power_normal;1240	}1241 1242	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",1243		 buf[1], buf[2]);1244 1245	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,1246			     sizeof(config), HID_FEATURE_REPORT);1247	if (ret != sizeof(config)) {1248		hid_err(hdev, "error requesting SMBus config\n");1249		if (ret >= 0)1250			ret = -EIO;1251		goto err_power_normal;1252	}1253 1254	config.retry_time = cpu_to_be16(1);1255 1256	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),1257				HID_FEATURE_REPORT);1258	if (ret != sizeof(config)) {1259		hid_err(hdev, "error setting SMBus config\n");1260		if (ret >= 0)1261			ret = -EIO;1262		goto err_power_normal;1263	}1264 1265	hid_set_drvdata(hdev, (void *)dev);1266	dev->hdev		= hdev;1267	dev->adap.owner		= THIS_MODULE;1268	dev->adap.class		= I2C_CLASS_HWMON;1269	dev->adap.algo		= &smbus_algorithm;1270	dev->adap.algo_data	= dev;1271	dev->adap.dev.parent	= &hdev->dev;1272	snprintf(dev->adap.name, sizeof(dev->adap.name),1273		 "CP2112 SMBus Bridge on hidraw%d",1274		 ((struct hidraw *)hdev->hidraw)->minor);1275	dev->hwversion = buf[2];1276	init_waitqueue_head(&dev->wait);1277 1278	hid_device_io_start(hdev);1279	ret = i2c_add_adapter(&dev->adap);1280	hid_device_io_stop(hdev);1281 1282	if (ret) {1283		hid_err(hdev, "error registering i2c adapter\n");1284		goto err_power_normal;1285	}1286 1287	hid_dbg(hdev, "adapter registered\n");1288 1289	dev->gc.label			= "cp2112_gpio";1290	dev->gc.direction_input		= cp2112_gpio_direction_input;1291	dev->gc.direction_output	= cp2112_gpio_direction_output;1292	dev->gc.set			= cp2112_gpio_set;1293	dev->gc.get			= cp2112_gpio_get;1294	dev->gc.base			= -1;1295	dev->gc.ngpio			= CP2112_GPIO_MAX_GPIO;1296	dev->gc.can_sleep		= 1;1297	dev->gc.parent			= &hdev->dev;1298 1299	girq = &dev->gc.irq;1300	gpio_irq_chip_set_chip(girq, &cp2112_gpio_irqchip);1301	/* The event comes from the outside so no parent handler */1302	girq->parent_handler = NULL;1303	girq->num_parents = 0;1304	girq->parents = NULL;1305	girq->default_type = IRQ_TYPE_NONE;1306	girq->handler = handle_simple_irq;1307	girq->threaded = true;1308 1309	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);1310 1311	ret = gpiochip_add_data(&dev->gc, dev);1312	if (ret < 0) {1313		hid_err(hdev, "error registering gpio chip\n");1314		goto err_free_i2c;1315	}1316 1317	ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);1318	if (ret < 0) {1319		hid_err(hdev, "error creating sysfs attrs\n");1320		goto err_gpiochip_remove;1321	}1322 1323	chmod_sysfs_attrs(hdev);1324	hid_hw_power(hdev, PM_HINT_NORMAL);1325 1326	return ret;1327 1328err_gpiochip_remove:1329	gpiochip_remove(&dev->gc);1330err_free_i2c:1331	i2c_del_adapter(&dev->adap);1332err_power_normal:1333	hid_hw_power(hdev, PM_HINT_NORMAL);1334err_hid_close:1335	hid_hw_close(hdev);1336err_hid_stop:1337	hid_hw_stop(hdev);1338	return ret;1339}1340 1341static void cp2112_remove(struct hid_device *hdev)1342{1343	struct cp2112_device *dev = hid_get_drvdata(hdev);1344 1345	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);1346	i2c_del_adapter(&dev->adap);1347 1348	if (dev->gpio_poll) {1349		dev->gpio_poll = false;1350		cancel_delayed_work_sync(&dev->gpio_poll_worker);1351	}1352 1353	gpiochip_remove(&dev->gc);1354	/* i2c_del_adapter has finished removing all i2c devices from our1355	 * adapter. Well behaved devices should no longer call our cp2112_xfer1356	 * and should have waited for any pending calls to finish. It has also1357	 * waited for device_unregister(&adap->dev) to complete. Therefore we1358	 * can safely free our struct cp2112_device.1359	 */1360	hid_hw_close(hdev);1361	hid_hw_stop(hdev);1362}1363 1364static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,1365			    u8 *data, int size)1366{1367	struct cp2112_device *dev = hid_get_drvdata(hdev);1368	struct cp2112_xfer_status_report *xfer = (void *)data;1369 1370	switch (data[0]) {1371	case CP2112_TRANSFER_STATUS_RESPONSE:1372		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",1373			xfer->status0, xfer->status1,1374			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));1375 1376		switch (xfer->status0) {1377		case STATUS0_IDLE:1378			dev->xfer_status = -EAGAIN;1379			break;1380		case STATUS0_BUSY:1381			dev->xfer_status = -EBUSY;1382			break;1383		case STATUS0_COMPLETE:1384			dev->xfer_status = be16_to_cpu(xfer->length);1385			break;1386		case STATUS0_ERROR:1387			switch (xfer->status1) {1388			case STATUS1_TIMEOUT_NACK:1389			case STATUS1_TIMEOUT_BUS:1390				dev->xfer_status = -ETIMEDOUT;1391				break;1392			default:1393				dev->xfer_status = -EIO;1394				break;1395			}1396			break;1397		default:1398			dev->xfer_status = -EINVAL;1399			break;1400		}1401 1402		atomic_set(&dev->xfer_avail, 1);1403		break;1404	case CP2112_DATA_READ_RESPONSE:1405		hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);1406 1407		dev->read_length = data[2];1408		if (dev->read_length > sizeof(dev->read_data))1409			dev->read_length = sizeof(dev->read_data);1410 1411		memcpy(dev->read_data, &data[3], dev->read_length);1412		atomic_set(&dev->read_avail, 1);1413		break;1414	default:1415		hid_err(hdev, "unknown report\n");1416 1417		return 0;1418	}1419 1420	wake_up_interruptible(&dev->wait);1421	return 1;1422}1423 1424static struct hid_driver cp2112_driver = {1425	.name		= "cp2112",1426	.id_table	= cp2112_devices,1427	.probe		= cp2112_probe,1428	.remove		= cp2112_remove,1429	.raw_event	= cp2112_raw_event,1430};1431 1432module_hid_driver(cp2112_driver);1433MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");1434MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");1435MODULE_LICENSE("GPL");1436 1437