/* * 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 #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_NO_RUNTIME_PM BIT(2) /* 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; bool wait; }; union command { u8 data[0]; struct cmd { __le16 reg; __u8 reportTypeID; __u8 opcode; } __packed c; }; #define I2C_HID_CMD(opcode_) \ .opcode = opcode_, .length = 4, \ .registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister) /* fetch HID descriptor */ static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 }; /* fetch report descriptors */ static const struct i2c_hid_cmd hid_report_descr_cmd = { .registerIndex = offsetof(struct i2c_hid_desc, wReportDescRegister), .opcode = 0x00, .length = 2 }; /* commands */ static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01), .wait = true }; static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) }; static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) }; static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) }; static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 }; /* * 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 */ u8 *argsbuf; /* Command arguments buffer */ unsigned long flags; /* device flags */ unsigned long quirks; /* Various quirks */ wait_queue_head_t wait; /* For waiting the interrupt */ struct i2c_hid_platform_data pdata; bool irq_wake_enabled; struct mutex reset_lock; }; static const struct i2c_hid_quirks { __u16 idVendor; __u16 idProduct; __u32 quirks; } i2c_hid_quirks[] = { { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752, I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, { USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755, I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV }, { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, I2C_HID_QUIRK_NO_IRQ_AFTER_RESET | I2C_HID_QUIRK_NO_RUNTIME_PM }, { 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_command(struct i2c_client *client, const struct i2c_hid_cmd *command, u8 reportID, u8 reportType, u8 *args, int args_len, unsigned char *buf_recv, int data_len) { struct i2c_hid *ihid = i2c_get_clientdata(client); union command *cmd = (union command *)ihid->cmdbuf; int ret; struct i2c_msg msg[2]; int msg_num = 1; int length = command->length; bool wait = command->wait; unsigned int registerIndex = command->registerIndex; /* special case for hid_descr_cmd */ if (command == &hid_descr_cmd) { cmd->c.reg = ihid->wHIDDescRegister; } else { cmd->data[0] = ihid->hdesc_buffer[registerIndex]; cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1]; } if (length > 2) { cmd->c.opcode = command->opcode; cmd->c.reportTypeID = reportID | reportType << 4; } memcpy(cmd->data + length, args, args_len); length += args_len; i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data); msg[0].addr = client->addr; msg[0].flags = client->flags & I2C_M_TEN; msg[0].len = length; msg[0].buf = cmd->data; if (data_len > 0) { msg[1].addr = client->addr; msg[1].flags = client->flags & I2C_M_TEN; msg[1].flags |= I2C_M_RD; msg[1].len = data_len; msg[1].buf = buf_recv; msg_num = 2; set_bit(I2C_HID_READ_PENDING, &ihid->flags); } if (wait) set_bit(I2C_HID_RESET_PENDING, &ihid->flags); ret = i2c_transfer(client->adapter, msg, msg_num); if (data_len > 0) clear_bit(I2C_HID_READ_PENDING, &ihid->flags); if (ret != msg_num) return ret < 0 ? ret : -EIO; ret = 0; if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) { msleep(100); } else if (wait) { 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; i2c_hid_dbg(ihid, "%s: finished.\n", __func__); } return ret; } static int i2c_hid_command(struct i2c_client *client, const struct i2c_hid_cmd *command, unsigned char *buf_recv, int data_len) { return __i2c_hid_command(client, command, 0, 0, NULL, 0, buf_recv, data_len); } static int i2c_hid_get_report(struct i2c_client *client, u8 reportType, u8 reportID, unsigned char *buf_recv, int data_len) { struct i2c_hid *ihid = i2c_get_clientdata(client); u8 args[3]; int ret; int args_len = 0; u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister); i2c_hid_dbg(ihid, "%s\n", __func__); if (reportID >= 0x0F) { args[args_len++] = reportID; reportID = 0x0F; } args[args_len++] = readRegister & 0xFF; args[args_len++] = readRegister >> 8; ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID, reportType, args, args_len, buf_recv, data_len); if (ret) { dev_err(&client->dev, "failed to retrieve report from device.\n"); return ret; } return 0; } /** * i2c_hid_set_or_send_report: forward an incoming report to the device * @client: the i2c_client of the device * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT * @reportID: the report ID * @buf: the actual data to transfer, without the report ID * @len: size of buf * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report */ static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType, u8 reportID, unsigned char *buf, size_t data_len, bool use_data) { struct i2c_hid *ihid = i2c_get_clientdata(client); u8 *args = ihid->argsbuf; const struct i2c_hid_cmd *hidcmd; int ret; u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister); u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister); u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength); u16 size; int args_len; int index = 0; i2c_hid_dbg(ihid, "%s\n", __func__); if (data_len > ihid->bufsize) return -EINVAL; size = 2 /* size */ + (reportID ? 1 : 0) /* reportID */ + data_len /* buf */; args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ + 2 /* dataRegister */ + size /* args */; if (!use_data && maxOutputLength == 0) return -ENOSYS; if (reportID >= 0x0F) { args[index++] = reportID; reportID = 0x0F; } /* * use the data register for feature reports or if the device does not * support the output register */ if (use_data) { args[index++] = dataRegister & 0xFF; args[index++] = dataRegister >> 8; hidcmd = &hid_set_report_cmd; } else { args[index++] = outputRegister & 0xFF; args[index++] = outputRegister >> 8; hidcmd = &hid_no_cmd; } args[index++] = size & 0xFF; args[index++] = size >> 8; if (reportID) args[index++] = reportID; memcpy(&args[index], buf, data_len); ret = __i2c_hid_command(client, hidcmd, reportID, reportType, args, args_len, NULL, 0); if (ret) { dev_err(&client->dev, "failed to set a report to device.\n"); return ret; } return data_len; } static int i2c_hid_set_power(struct i2c_client *client, int power_state) { struct i2c_hid *ihid = i2c_get_clientdata(client); 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_command(client, &hid_set_power_cmd, NULL, 0); /* Device was already activated */ if (!ret) goto set_pwr_exit; } ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state, 0, NULL, 0, NULL, 0); if (ret) dev_err(&client->dev, "failed to change power setting.\n"); set_pwr_exit: return ret; } static int i2c_hid_hwreset(struct i2c_client *client) { struct i2c_hid *ihid = i2c_get_clientdata(client); 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(client, I2C_HID_PWR_ON); if (ret) goto out_unlock; /* * 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 and that some devices * rely on this. */ usleep_range(1000, 5000); i2c_hid_dbg(ihid, "resetting...\n"); ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0); if (ret) { dev_err(&client->dev, "failed to reset device.\n"); i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); } 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 ((ret_size > size) || (ret_size < 2)) { 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)) 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->argsbuf); kfree(ihid->cmdbuf); ihid->inbuf = NULL; ihid->rawbuf = NULL; ihid->cmdbuf = NULL; ihid->argsbuf = 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 args_len = sizeof(__u8) + /* ReportID */ sizeof(__u8) + /* optional ReportID byte */ sizeof(__u16) + /* data register */ sizeof(__u16) + /* size of the report */ report_size; /* report */ ihid->inbuf = kzalloc(report_size, GFP_KERNEL); ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); ihid->argsbuf = kzalloc(args_len, GFP_KERNEL); ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL); if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !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; /* +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(client, 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); return count; } static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, size_t count, unsigned char report_type, bool use_data) { 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); if (report_id) { buf++; count--; } ret = i2c_hid_set_or_send_report(client, report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, report_id, buf, count, use_data); if (report_id && ret >= 0) ret++; /* add report_id to the number of transfered 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(client); 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_command(client, &hid_report_descr_cmd, 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); int ret = 0; ret = pm_runtime_get_sync(&client->dev); if (ret < 0) return ret; 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); /* Save some power */ pm_runtime_put(&client->dev); } static int i2c_hid_power(struct hid_device *hid, int lvl) { struct i2c_client *client = hid->driver_data; struct i2c_hid *ihid = i2c_get_clientdata(client); i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl); switch (lvl) { case PM_HINT_FULLON: pm_runtime_get_sync(&client->dev); break; case PM_HINT_NORMAL: pm_runtime_put(&client->dev); break; } return 0; } 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, .power = i2c_hid_power, .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 ret; /* 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"); ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, sizeof(struct i2c_hid_desc)); if (ret) { dev_err(&client->dev, "hid_descr_cmd failed\n"); 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(&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(&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; } #ifdef CONFIG_ACPI static const struct acpi_device_id i2c_hid_acpi_blacklist[] = { /* * The CHPN0001 ACPI device, which is used to describe the Chipone * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible. */ {"CHPN0001", 0 }, { }, }; static int i2c_hid_acpi_pdata(struct i2c_client *client, struct i2c_hid_platform_data *pdata) { static guid_t i2c_hid_guid = GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); union acpi_object *obj; struct acpi_device *adev; acpi_handle handle; handle = ACPI_HANDLE(&client->dev); if (!handle || acpi_bus_get_device(handle, &adev)) { dev_err(&client->dev, "Error could not get ACPI device\n"); return -ENODEV; } if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0) return -ENODEV; obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, ACPI_TYPE_INTEGER); if (!obj) { dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n"); return -ENODEV; } pdata->hid_descriptor_address = obj->integer.value; ACPI_FREE(obj); return 0; } static void i2c_hid_acpi_fix_up_power(struct device *dev) { struct acpi_device *adev; adev = ACPI_COMPANION(dev); if (adev) acpi_device_fix_up_power(adev); } static const struct acpi_device_id i2c_hid_acpi_match[] = { {"ACPI0C50", 0 }, {"PNP0C50", 0 }, { }, }; MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match); #else static inline int i2c_hid_acpi_pdata(struct i2c_client *client, struct i2c_hid_platform_data *pdata) { return -ENODEV; } static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {} #endif #ifdef CONFIG_OF static int i2c_hid_of_probe(struct i2c_client *client, struct i2c_hid_platform_data *pdata) { struct device *dev = &client->dev; u32 val; int ret; ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val); if (ret) { dev_err(&client->dev, "HID register address not provided\n"); return -ENODEV; } if (val >> 16) { dev_err(&client->dev, "Bad HID register address: 0x%08x\n", val); return -EINVAL; } pdata->hid_descriptor_address = val; return 0; } static const struct of_device_id i2c_hid_of_match[] = { { .compatible = "hid-over-i2c" }, {}, }; MODULE_DEVICE_TABLE(of, i2c_hid_of_match); #else static inline int i2c_hid_of_probe(struct i2c_client *client, struct i2c_hid_platform_data *pdata) { return -ENODEV; } #endif static void i2c_hid_fwnode_probe(struct i2c_client *client, struct i2c_hid_platform_data *pdata) { u32 val; if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms", &val)) pdata->post_power_delay_ms = val; } static int i2c_hid_probe(struct i2c_client *client, const struct i2c_device_id *dev_id) { int ret; struct i2c_hid *ihid; struct hid_device *hid; __u16 hidRegister; struct i2c_hid_platform_data *platform_data = client->dev.platform_data; 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; if (client->dev.of_node) { ret = i2c_hid_of_probe(client, &ihid->pdata); if (ret) return ret; } else if (!platform_data) { ret = i2c_hid_acpi_pdata(client, &ihid->pdata); if (ret) return ret; } else { ihid->pdata = *platform_data; } /* Parse platform agnostic common properties from ACPI / device tree */ i2c_hid_fwnode_probe(client, &ihid->pdata); ihid->pdata.supplies[0].supply = "vdd"; ihid->pdata.supplies[1].supply = "vddl"; ret = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(ihid->pdata.supplies), ihid->pdata.supplies); if (ret) return ret; ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), ihid->pdata.supplies); if (ret < 0) return ret; if (ihid->pdata.post_power_delay_ms) msleep(ihid->pdata.post_power_delay_ms); i2c_set_clientdata(client, ihid); ihid->client = client; hidRegister = ihid->pdata.hid_descriptor_address; ihid->wHIDDescRegister = cpu_to_le16(hidRegister); 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_regulator; i2c_hid_acpi_fix_up_power(&client->dev); pm_runtime_get_noresume(&client->dev); pm_runtime_set_active(&client->dev); pm_runtime_enable(&client->dev); 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_pm; } ret = i2c_hid_fetch_hid_descriptor(ihid); if (ret < 0) goto err_pm; ret = i2c_hid_init_irq(client); if (ret < 0) goto err_pm; 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 %04hX:%04hX", client->name, hid->vendor, 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; } if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM)) pm_runtime_put(&client->dev); return 0; err_mem_free: hid_destroy_device(hid); err_irq: free_irq(client->irq, ihid); err_pm: pm_runtime_put_noidle(&client->dev); pm_runtime_disable(&client->dev); err_regulator: regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), ihid->pdata.supplies); i2c_hid_free_buffers(ihid); return ret; } static int i2c_hid_remove(struct i2c_client *client) { struct i2c_hid *ihid = i2c_get_clientdata(client); struct hid_device *hid; if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM)) pm_runtime_get_sync(&client->dev); pm_runtime_disable(&client->dev); pm_runtime_set_suspended(&client->dev); pm_runtime_put_noidle(&client->dev); hid = ihid->hid; hid_destroy_device(hid); free_irq(client->irq, ihid); if (ihid->bufsize) i2c_hid_free_buffers(ihid); regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), ihid->pdata.supplies); return 0; } static void i2c_hid_shutdown(struct i2c_client *client) { struct i2c_hid *ihid = i2c_get_clientdata(client); i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); free_irq(client->irq, ihid); } #ifdef CONFIG_PM_SLEEP static int i2c_hid_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; if (hid->driver && hid->driver->suspend) { /* * Wake up the device so that IO issues in * HID driver's suspend code can succeed. */ ret = pm_runtime_resume(dev); if (ret < 0) return ret; ret = hid->driver->suspend(hid, PMSG_SUSPEND); if (ret < 0) return ret; } if (!pm_runtime_suspended(dev)) { /* Save some power */ i2c_hid_set_power(client, 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 { regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies), ihid->pdata.supplies); } return 0; } static int i2c_hid_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)) { ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies), ihid->pdata.supplies); if (ret) hid_warn(hid, "Failed to enable supplies: %d\n", ret); if (ihid->pdata.post_power_delay_ms) msleep(ihid->pdata.post_power_delay_ms); } 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); } /* We'll resume to full power */ pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); 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. */ ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); if (ret) return ret; if (hid->driver && hid->driver->reset_resume) { ret = hid->driver->reset_resume(hid); return ret; } return 0; } #endif #ifdef CONFIG_PM static int i2c_hid_runtime_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); disable_irq(client->irq); return 0; } static int i2c_hid_runtime_resume(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); enable_irq(client->irq); i2c_hid_set_power(client, I2C_HID_PWR_ON); return 0; } #endif static const struct dev_pm_ops i2c_hid_pm = { SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume) SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume, NULL) }; static const struct i2c_device_id i2c_hid_id_table[] = { { "hid", 0 }, { "hid-over-i2c", 0 }, { }, }; MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table); static struct i2c_driver i2c_hid_driver = { .driver = { .name = "i2c_hid", .pm = &i2c_hid_pm, .acpi_match_table = ACPI_PTR(i2c_hid_acpi_match), .of_match_table = of_match_ptr(i2c_hid_of_match), }, .probe = i2c_hid_probe, .remove = i2c_hid_remove, .shutdown = i2c_hid_shutdown, .id_table = i2c_hid_id_table, }; module_i2c_driver(i2c_hid_driver); MODULE_DESCRIPTION("HID over I2C core driver"); MODULE_AUTHOR("Benjamin Tissoires "); MODULE_LICENSE("GPL");