/* * HID over I2C protocol implementation * * Copyright (c) 2012 Benjamin Tissoires * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France * Copyright (c) 2012 Red Hat, Inc * * This code is partly based on "USB HID support for Linux": * * Copyright (c) 1999 Andreas Gal * Copyright (c) 2000-2005 Vojtech Pavlik * Copyright (c) 2005 Michael Haboustak for Concept2, Inc * Copyright (c) 2007-2008 Oliver Neukum * Copyright (c) 2006-2010 Jiri Kosina * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of this archive for * more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../hid-ids.h" #include "i2c-hid.h" /* quirks to control the device */ #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0) #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1) #define I2C_HID_QUIRK_BOGUS_IRQ BIT(4) #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(5) #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(6) #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(7) /* Command opcodes */ #define I2C_HID_OPCODE_RESET 0x01 #define I2C_HID_OPCODE_GET_REPORT 0x02 #define I2C_HID_OPCODE_SET_REPORT 0x03 #define I2C_HID_OPCODE_GET_IDLE 0x04 #define I2C_HID_OPCODE_SET_IDLE 0x05 #define I2C_HID_OPCODE_GET_PROTOCOL 0x06 #define I2C_HID_OPCODE_SET_PROTOCOL 0x07 #define I2C_HID_OPCODE_SET_POWER 0x08 /* flags */ #define I2C_HID_STARTED 0 #define I2C_HID_RESET_PENDING 1 #define I2C_HID_READ_PENDING 2 #define I2C_HID_PWR_ON 0x00 #define I2C_HID_PWR_SLEEP 0x01 /* debug option */ static bool debug; module_param(debug, bool, 0444); MODULE_PARM_DESC(debug, "print a lot of debug information"); #define i2c_hid_dbg(ihid, fmt, arg...) \ do { \ if (debug) \ dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \ } while (0) struct i2c_hid_desc { __le16 wHIDDescLength; __le16 bcdVersion; __le16 wReportDescLength; __le16 wReportDescRegister; __le16 wInputRegister; __le16 wMaxInputLength; __le16 wOutputRegister; __le16 wMaxOutputLength; __le16 wCommandRegister; __le16 wDataRegister; __le16 wVendorID; __le16 wProductID; __le16 wVersionID; __le32 reserved; } __packed; struct i2c_hid_cmd { unsigned int registerIndex; __u8 opcode; unsigned int length; }; #define I2C_HID_CMD(opcode_) \ .opcode = opcode_, .length = 4, \ .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister) /* commands */ static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) }; /* * These definitions are not used here, but are defined by the spec. * Keeping them here for documentation purposes. * * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) }; * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) }; * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) }; * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) }; */ /* The main device structure */ struct i2c_hid { struct i2c_client *client; /* i2c client */ struct hid_device *hid; /* pointer to corresponding HID dev */ union { __u8 hdesc_buffer[sizeof(struct i2c_hid_desc)]; struct i2c_hid_desc hdesc; /* the HID Descriptor */ }; __le16 wHIDDescRegister; /* location of the i2c * register of the HID * descriptor. */ unsigned int bufsize; /* i2c buffer size */ u8 *inbuf; /* Input buffer */ u8 *rawbuf; /* Raw Input buffer */ u8 *cmdbuf; /* Command buffer */ unsigned long flags; /* device flags */ unsigned long quirks; /* Various quirks */ wait_queue_head_t wait; /* For waiting the interrupt */ bool irq_wake_enabled; struct mutex reset_lock; struct i2chid_ops *ops; }; static const struct i2c_hid_quirks { __u16 idVendor; __u16 idProduct; __u32 quirks; } i2c_hid_quirks[] = { { USB_VENDOR_ID_WEIDA, HID_ANY_ID, I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15, I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118, I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID, I2C_HID_QUIRK_RESET_ON_RESUME }, { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393, I2C_HID_QUIRK_RESET_ON_RESUME }, { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720, I2C_HID_QUIRK_BAD_INPUT_SIZE }, /* * Sending the wakeup after reset actually break ELAN touchscreen controller */ { USB_VENDOR_ID_ELAN, HID_ANY_ID, I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET | I2C_HID_QUIRK_BOGUS_IRQ }, { 0, 0 } }; /* * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device * @idVendor: the 16-bit vendor ID * @idProduct: the 16-bit product ID * * Returns: a u32 quirks value. */ static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct) { u32 quirks = 0; int n; for (n = 0; i2c_hid_quirks[n].idVendor; n++) if (i2c_hid_quirks[n].idVendor == idVendor && (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID || i2c_hid_quirks[n].idProduct == idProduct)) quirks = i2c_hid_quirks[n].quirks; return quirks; } static int i2c_hid_xfer(struct i2c_hid *ihid, u8 *send_buf, int send_len, u8 *recv_buf, int recv_len) { struct i2c_client *client = ihid->client; struct i2c_msg msgs[2] = { 0 }; int n = 0; int ret; if (send_len) { i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, send_len, send_buf); msgs[n].addr = client->addr; msgs[n].flags = client->flags & I2C_M_TEN; msgs[n].len = send_len; msgs[n].buf = send_buf; n++; } if (recv_len) { msgs[n].addr = client->addr; msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_RD; msgs[n].len = recv_len; msgs[n].buf = recv_buf; n++; set_bit(I2C_HID_READ_PENDING, &ihid->flags); } ret = i2c_transfer(client->adapter, msgs, n); if (recv_len) clear_bit(I2C_HID_READ_PENDING, &ihid->flags); if (ret != n) return ret < 0 ? ret : -EIO; return 0; } static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg, void *buf, size_t len) { *(__le16 *)ihid->cmdbuf = reg; return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len); } static size_t i2c_hid_encode_command(u8 *buf, u8 opcode, int report_type, int report_id) { size_t length = 0; if (report_id < 0x0F) { buf[length++] = report_type << 4 | report_id; buf[length++] = opcode; } else { buf[length++] = report_type << 4 | 0x0F; buf[length++] = opcode; buf[length++] = report_id; } return length; } static int __i2c_hid_command(struct i2c_hid *ihid, const struct i2c_hid_cmd *command, u8 reportID, u8 reportType, u8 *args, int args_len, unsigned char *buf_recv, int data_len) { int length = command->length; unsigned int registerIndex = command->registerIndex; ihid->cmdbuf[0] = ihid->hdesc_buffer[registerIndex]; ihid->cmdbuf[1] = ihid->hdesc_buffer[registerIndex + 1]; if (length > 2) { length = sizeof(__le16) + /* register */ i2c_hid_encode_command(ihid->cmdbuf + sizeof(__le16), command->opcode, reportType, reportID); } memcpy(ihid->cmdbuf + length, args, args_len); length += args_len; return i2c_hid_xfer(ihid, ihid->cmdbuf, length, buf_recv, data_len); } static int i2c_hid_get_report(struct i2c_hid *ihid, u8 reportType, u8 reportID, unsigned char *buf_recv, int data_len) { u8 args[2]; int ret; int args_len = 0; u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister); i2c_hid_dbg(ihid, "%s\n", __func__); args[args_len++] = readRegister & 0xFF; args[args_len++] = readRegister >> 8; ret = __i2c_hid_command(ihid, &hid_get_report_cmd, reportID, reportType, args, args_len, buf_recv, data_len); if (ret) { dev_err(&ihid->client->dev, "failed to retrieve report from device.\n"); return ret; } return 0; } static size_t i2c_hid_format_report(u8 *buf, int report_id, const u8 *data, size_t size) { size_t length = sizeof(__le16); /* reserve space to store size */ if (report_id) buf[length++] = report_id; memcpy(buf + length, data, size); length += size; /* Store overall size in the beginning of the buffer */ put_unaligned_le16(length, buf); return length; } /** * i2c_hid_set_or_send_report: forward an incoming report to the device * @ihid: the i2c hid device * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT * @report_id: the report ID * @buf: the actual data to transfer, without the report ID * @data_len: size of buf * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report */ static int i2c_hid_set_or_send_report(struct i2c_hid *ihid, u8 report_type, u8 report_id, const u8 *buf, size_t data_len, bool do_set) { size_t length = 0; int error; i2c_hid_dbg(ihid, "%s\n", __func__); if (data_len > ihid->bufsize) return -EINVAL; if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0) return -ENOSYS; if (do_set) { /* Command register goes first */ *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; length += sizeof(__le16); /* Next is SET_REPORT command */ length += i2c_hid_encode_command(ihid->cmdbuf + length, I2C_HID_OPCODE_SET_REPORT, report_type, report_id); /* * Report data will go into the data register. Because * command can be either 2 or 3 bytes destination for * the data register may be not aligned. */ put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), ihid->cmdbuf + length); length += sizeof(__le16); } else { /* * With simple "send report" all data goes into the output * register. */ *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;; length += sizeof(__le16); } length += i2c_hid_format_report(ihid->cmdbuf + length, report_id, buf, data_len); error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); if (error) { dev_err(&ihid->client->dev, "failed to set a report to device: %d\n", error); return error; } return data_len; } static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state) { size_t length; /* SET_POWER uses command register */ *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; length = sizeof(__le16); /* Now the command itself */ length += i2c_hid_encode_command(ihid->cmdbuf + length, I2C_HID_OPCODE_SET_POWER, 0, power_state); return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); } static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state) { int ret; i2c_hid_dbg(ihid, "%s\n", __func__); /* * Some devices require to send a command to wakeup before power on. * The call will get a return value (EREMOTEIO) but device will be * triggered and activated. After that, it goes like a normal device. */ if (power_state == I2C_HID_PWR_ON && ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) { ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON); /* Device was already activated */ if (!ret) goto set_pwr_exit; } ret = i2c_hid_set_power_command(ihid, power_state); if (ret) dev_err(&ihid->client->dev, "failed to change power setting.\n"); set_pwr_exit: /* * The HID over I2C specification states that if a DEVICE needs time * after the PWR_ON request, it should utilise CLOCK stretching. * However, it has been observered that the Windows driver provides a * 1ms sleep between the PWR_ON and RESET requests. * According to Goodix Windows even waits 60 ms after (other?) * PWR_ON requests. Testing has confirmed that several devices * will not work properly without a delay after a PWR_ON request. */ if (!ret && power_state == I2C_HID_PWR_ON) msleep(60); return ret; } static int i2c_hid_execute_reset(struct i2c_hid *ihid) { size_t length = 0; int ret; i2c_hid_dbg(ihid, "resetting...\n"); /* Prepare reset command. Command register goes first. */ *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; length += sizeof(__le16); /* Next is RESET command itself */ length += i2c_hid_encode_command(ihid->cmdbuf + length, I2C_HID_OPCODE_RESET, 0, 0); set_bit(I2C_HID_RESET_PENDING, &ihid->flags); ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); if (ret) { dev_err(&ihid->client->dev, "failed to reset device.\n"); goto out; } if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) { msleep(100); goto out; } i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); if (!wait_event_timeout(ihid->wait, !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), msecs_to_jiffies(5000))) { ret = -ENODATA; goto out; } i2c_hid_dbg(ihid, "%s: finished.\n", __func__); out: clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); return ret; } static int i2c_hid_hwreset(struct i2c_hid *ihid) { int ret; i2c_hid_dbg(ihid, "%s\n", __func__); /* * This prevents sending feature reports while the device is * being reset. Otherwise we may lose the reset complete * interrupt. */ mutex_lock(&ihid->reset_lock); ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); if (ret) goto out_unlock; ret = i2c_hid_execute_reset(ihid); if (ret) { dev_err(&ihid->client->dev, "failed to reset device: %d\n", ret); i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); goto out_unlock; } /* At least some SIS devices need this after reset */ if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET)) ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); out_unlock: mutex_unlock(&ihid->reset_lock); return ret; } static void i2c_hid_get_input(struct i2c_hid *ihid) { int ret; u32 ret_size; int size = le16_to_cpu(ihid->hdesc.wMaxInputLength); if (size > ihid->bufsize) size = ihid->bufsize; ret = i2c_master_recv(ihid->client, ihid->inbuf, size); if (ret != size) { if (ret < 0) return; dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", __func__, ret, size); return; } ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8; if (!ret_size) { /* host or device initiated RESET completed */ if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) wake_up(&ihid->wait); return; } if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) { dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but " "there's no data\n", __func__); return; } if ((ret_size > size) || (ret_size < 2)) { if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) { ihid->inbuf[0] = size & 0xff; ihid->inbuf[1] = size >> 8; ret_size = size; } else { dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n", __func__, size, ret_size); return; } } i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); if (test_bit(I2C_HID_STARTED, &ihid->flags)) { pm_wakeup_event(&ihid->client->dev, 0); hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2, ret_size - 2, 1); } return; } static irqreturn_t i2c_hid_irq(int irq, void *dev_id) { struct i2c_hid *ihid = dev_id; if (test_bit(I2C_HID_READ_PENDING, &ihid->flags)) return IRQ_HANDLED; i2c_hid_get_input(ihid); return IRQ_HANDLED; } static int i2c_hid_get_report_length(struct hid_report *report) { return ((report->size - 1) >> 3) + 1 + report->device->report_enum[report->type].numbered + 2; } /* * Traverse the supplied list of reports and find the longest */ static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, unsigned int *max) { struct hid_report *report; unsigned int size; /* We should not rely on wMaxInputLength, as some devices may set it to * a wrong length. */ list_for_each_entry(report, &hid->report_enum[type].report_list, list) { size = i2c_hid_get_report_length(report); if (*max < size) *max = size; } } static void i2c_hid_free_buffers(struct i2c_hid *ihid) { kfree(ihid->inbuf); kfree(ihid->rawbuf); kfree(ihid->cmdbuf); ihid->inbuf = NULL; ihid->rawbuf = NULL; ihid->cmdbuf = NULL; ihid->bufsize = 0; } static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) { /* * The worst case is computed from the set_report command with a * reportID > 15 and the maximum report length. */ int cmd_len = sizeof(__le16) + /* command register */ sizeof(u8) + /* encoded report type/ID */ sizeof(u8) + /* opcode */ sizeof(u8) + /* optional 3rd byte report ID */ sizeof(__le16) + /* data register */ sizeof(__le16) + /* report data size */ sizeof(u8) + /* report ID if numbered report */ report_size; ihid->inbuf = kzalloc(report_size, GFP_KERNEL); ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL); if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) { i2c_hid_free_buffers(ihid); return -ENOMEM; } ihid->bufsize = report_size; return 0; } static int i2c_hid_get_raw_report(struct hid_device *hid, unsigned char report_number, __u8 *buf, size_t count, unsigned char report_type) { struct i2c_client *client = hid->driver_data; struct i2c_hid *ihid = i2c_get_clientdata(client); size_t ret_count, ask_count; int ret; if (report_type == HID_OUTPUT_REPORT) return -EINVAL; /* * In case of unnumbered reports the response from the device will * not have the report ID that the upper layers expect, so we need * to stash it the buffer ourselves and adjust the data size. */ if (!report_number) { buf[0] = 0; buf++; count--; } /* +2 bytes to include the size of the reply in the query buffer */ ask_count = min(count + 2, (size_t)ihid->bufsize); ret = i2c_hid_get_report(ihid, report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, report_number, ihid->rawbuf, ask_count); if (ret < 0) return ret; ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8); if (ret_count <= 2) return 0; ret_count = min(ret_count, ask_count); /* The query buffer contains the size, dropping it in the reply */ count = min(count, ret_count - 2); memcpy(buf, ihid->rawbuf + 2, count); if (!report_number) count++; return count; } static int i2c_hid_output_raw_report(struct hid_device *hid, const u8 *buf, size_t count, u8 report_type, bool do_set) { struct i2c_client *client = hid->driver_data; struct i2c_hid *ihid = i2c_get_clientdata(client); int report_id = buf[0]; int ret; if (report_type == HID_INPUT_REPORT) return -EINVAL; mutex_lock(&ihid->reset_lock); /* * Note that both numbered and unnumbered reports passed here * are supposed to have report ID stored in the 1st byte of the * buffer, so we strip it off unconditionally before passing payload * to i2c_hid_set_or_send_report which takes care of encoding * everything properly. */ ret = i2c_hid_set_or_send_report(ihid, report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, report_id, buf + 1, count - 1, do_set); if (ret >= 0) ret++; /* add report_id to the number of transferred bytes */ mutex_unlock(&ihid->reset_lock); return ret; } static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count) { return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT, false); } static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, __u8 *buf, size_t len, unsigned char rtype, int reqtype) { switch (reqtype) { case HID_REQ_GET_REPORT: return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype); case HID_REQ_SET_REPORT: if (buf[0] != reportnum) return -EINVAL; return i2c_hid_output_raw_report(hid, buf, len, rtype, true); default: return -EIO; } } static int i2c_hid_parse(struct hid_device *hid) { struct i2c_client *client = hid->driver_data; struct i2c_hid *ihid = i2c_get_clientdata(client); struct i2c_hid_desc *hdesc = &ihid->hdesc; unsigned int rsize; char *rdesc; int ret; int tries = 3; char *use_override; i2c_hid_dbg(ihid, "entering %s\n", __func__); rsize = le16_to_cpu(hdesc->wReportDescLength); if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { dbg_hid("weird size of report descriptor (%u)\n", rsize); return -EINVAL; } do { ret = i2c_hid_hwreset(ihid); if (ret) msleep(1000); } while (tries-- > 0 && ret); if (ret) return ret; use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, &rsize); if (use_override) { rdesc = use_override; i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); } else { rdesc = kzalloc(rsize, GFP_KERNEL); if (!rdesc) { dbg_hid("couldn't allocate rdesc memory\n"); return -ENOMEM; } i2c_hid_dbg(ihid, "asking HID report descriptor\n"); ret = i2c_hid_read_register(ihid, ihid->hdesc.wReportDescRegister, rdesc, rsize); if (ret) { hid_err(hid, "reading report descriptor failed\n"); kfree(rdesc); return -EIO; } } i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); ret = hid_parse_report(hid, rdesc, rsize); if (!use_override) kfree(rdesc); if (ret) { dbg_hid("parsing report descriptor failed\n"); return ret; } return 0; } static int i2c_hid_start(struct hid_device *hid) { struct i2c_client *client = hid->driver_data; struct i2c_hid *ihid = i2c_get_clientdata(client); int ret; unsigned int bufsize = HID_MIN_BUFFER_SIZE; i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); if (bufsize > ihid->bufsize) { disable_irq(client->irq); i2c_hid_free_buffers(ihid); ret = i2c_hid_alloc_buffers(ihid, bufsize); enable_irq(client->irq); if (ret) return ret; } return 0; } static void i2c_hid_stop(struct hid_device *hid) { hid->claimed = 0; } static int i2c_hid_open(struct hid_device *hid) { struct i2c_client *client = hid->driver_data; struct i2c_hid *ihid = i2c_get_clientdata(client); set_bit(I2C_HID_STARTED, &ihid->flags); return 0; } static void i2c_hid_close(struct hid_device *hid) { struct i2c_client *client = hid->driver_data; struct i2c_hid *ihid = i2c_get_clientdata(client); clear_bit(I2C_HID_STARTED, &ihid->flags); } struct hid_ll_driver i2c_hid_ll_driver = { .parse = i2c_hid_parse, .start = i2c_hid_start, .stop = i2c_hid_stop, .open = i2c_hid_open, .close = i2c_hid_close, .output_report = i2c_hid_output_report, .raw_request = i2c_hid_raw_request, }; EXPORT_SYMBOL_GPL(i2c_hid_ll_driver); static int i2c_hid_init_irq(struct i2c_client *client) { struct i2c_hid *ihid = i2c_get_clientdata(client); unsigned long irqflags = 0; int ret; dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); if (!irq_get_trigger_type(client->irq)) irqflags = IRQF_TRIGGER_LOW; ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, irqflags | IRQF_ONESHOT, client->name, ihid); if (ret < 0) { dev_warn(&client->dev, "Could not register for %s interrupt, irq = %d," " ret = %d\n", client->name, client->irq, ret); return ret; } return 0; } static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) { struct i2c_client *client = ihid->client; struct i2c_hid_desc *hdesc = &ihid->hdesc; unsigned int dsize; int error; /* i2c hid fetch using a fixed descriptor size (30 bytes) */ if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); ihid->hdesc = *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); } else { i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); error = i2c_hid_read_register(ihid, ihid->wHIDDescRegister, &ihid->hdesc, sizeof(ihid->hdesc)); if (error) { dev_err(&ihid->client->dev, "failed to fetch HID descriptor: %d\n", error); return -ENODEV; } } /* Validate the length of HID descriptor, the 4 first bytes: * bytes 0-1 -> length * bytes 2-3 -> bcdVersion (has to be 1.00) */ /* check bcdVersion == 1.0 */ if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { dev_err(&ihid->client->dev, "unexpected HID descriptor bcdVersion (0x%04hx)\n", le16_to_cpu(hdesc->bcdVersion)); return -ENODEV; } /* Descriptor length should be 30 bytes as per the specification */ dsize = le16_to_cpu(hdesc->wHIDDescLength); if (dsize != sizeof(struct i2c_hid_desc)) { dev_err(&ihid->client->dev, "weird size of HID descriptor (%u)\n", dsize); return -ENODEV; } i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); return 0; } static int i2c_hid_core_power_up(struct i2c_hid *ihid) { if (!ihid->ops->power_up) return 0; return ihid->ops->power_up(ihid->ops); } static void i2c_hid_core_power_down(struct i2c_hid *ihid) { if (!ihid->ops->power_down) return; ihid->ops->power_down(ihid->ops); } static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid) { if (!ihid->ops->shutdown_tail) return; ihid->ops->shutdown_tail(ihid->ops); } int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, u16 hid_descriptor_address, u32 quirks) { int ret; struct i2c_hid *ihid; struct hid_device *hid; dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); if (!client->irq) { dev_err(&client->dev, "HID over i2c has not been provided an Int IRQ\n"); return -EINVAL; } if (client->irq < 0) { if (client->irq != -EPROBE_DEFER) dev_err(&client->dev, "HID over i2c doesn't have a valid IRQ\n"); return client->irq; } ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); if (!ihid) return -ENOMEM; ihid->ops = ops; ret = i2c_hid_core_power_up(ihid); if (ret) return ret; i2c_set_clientdata(client, ihid); ihid->client = client; ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address); init_waitqueue_head(&ihid->wait); mutex_init(&ihid->reset_lock); /* we need to allocate the command buffer without knowing the maximum * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the * real computation later. */ ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); if (ret < 0) goto err_powered; device_enable_async_suspend(&client->dev); /* Make sure there is something at this address */ ret = i2c_smbus_read_byte(client); if (ret < 0) { dev_dbg(&client->dev, "nothing at this address: %d\n", ret); ret = -ENXIO; goto err_powered; } ret = i2c_hid_fetch_hid_descriptor(ihid); if (ret < 0) { dev_err(&client->dev, "Failed to fetch the HID Descriptor\n"); goto err_powered; } ret = i2c_hid_init_irq(client); if (ret < 0) goto err_powered; hid = hid_allocate_device(); if (IS_ERR(hid)) { ret = PTR_ERR(hid); goto err_irq; } ihid->hid = hid; hid->driver_data = client; hid->ll_driver = &i2c_hid_ll_driver; hid->dev.parent = &client->dev; hid->bus = BUS_I2C; hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); hid->product = le16_to_cpu(ihid->hdesc.wProductID); snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X", client->name, (u16)hid->vendor, (u16)hid->product); strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); ret = hid_add_device(hid); if (ret) { if (ret != -ENODEV) hid_err(client, "can't add hid device: %d\n", ret); goto err_mem_free; } hid->quirks |= quirks; return 0; err_mem_free: hid_destroy_device(hid); err_irq: free_irq(client->irq, ihid); err_powered: i2c_hid_core_power_down(ihid); i2c_hid_free_buffers(ihid); return ret; } EXPORT_SYMBOL_GPL(i2c_hid_core_probe); int i2c_hid_core_remove(struct i2c_client *client) { struct i2c_hid *ihid = i2c_get_clientdata(client); struct hid_device *hid; hid = ihid->hid; hid_destroy_device(hid); free_irq(client->irq, ihid); if (ihid->bufsize) i2c_hid_free_buffers(ihid); i2c_hid_core_power_down(ihid); return 0; } EXPORT_SYMBOL_GPL(i2c_hid_core_remove); void i2c_hid_core_shutdown(struct i2c_client *client) { struct i2c_hid *ihid = i2c_get_clientdata(client); i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); free_irq(client->irq, ihid); i2c_hid_core_shutdown_tail(ihid); } EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown); #ifdef CONFIG_PM_SLEEP static int i2c_hid_core_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct i2c_hid *ihid = i2c_get_clientdata(client); struct hid_device *hid = ihid->hid; int ret; int wake_status; ret = hid_driver_suspend(hid, PMSG_SUSPEND); if (ret < 0) return ret; /* Save some power */ i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); disable_irq(client->irq); if (device_may_wakeup(&client->dev)) { wake_status = enable_irq_wake(client->irq); if (!wake_status) ihid->irq_wake_enabled = true; else hid_warn(hid, "Failed to enable irq wake: %d\n", wake_status); } else { i2c_hid_core_power_down(ihid); } return 0; } static int i2c_hid_core_resume(struct device *dev) { int ret; struct i2c_client *client = to_i2c_client(dev); struct i2c_hid *ihid = i2c_get_clientdata(client); struct hid_device *hid = ihid->hid; int wake_status; if (!device_may_wakeup(&client->dev)) { i2c_hid_core_power_up(ihid); } else if (ihid->irq_wake_enabled) { wake_status = disable_irq_wake(client->irq); if (!wake_status) ihid->irq_wake_enabled = false; else hid_warn(hid, "Failed to disable irq wake: %d\n", wake_status); } enable_irq(client->irq); /* Instead of resetting device, simply powers the device on. This * solves "incomplete reports" on Raydium devices 2386:3118 and * 2386:4B33 and fixes various SIS touchscreens no longer sending * data after a suspend/resume. * * However some ALPS touchpads generate IRQ storm without reset, so * let's still reset them here. */ if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) ret = i2c_hid_hwreset(ihid); else ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); if (ret) return ret; return hid_driver_reset_resume(hid); } #endif const struct dev_pm_ops i2c_hid_core_pm = { SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume) }; EXPORT_SYMBOL_GPL(i2c_hid_core_pm); MODULE_DESCRIPTION("HID over I2C core driver"); MODULE_AUTHOR("Benjamin Tissoires "); MODULE_LICENSE("GPL");