diff options
Diffstat (limited to 'drivers/hid/i2c-hid/i2c-hid.c')
| -rw-r--r-- | drivers/hid/i2c-hid/i2c-hid.c | 979 |
1 files changed, 979 insertions, 0 deletions
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c new file mode 100644 index 000000000000..12e4fdc810bf --- /dev/null +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -0,0 +1,979 @@ +/* + * HID over I2C protocol implementation + * + * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com> + * 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 <vojtech@suse.cz> + * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> 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 <linux/module.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/input.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/pm.h> +#include <linux/device.h> +#include <linux/wait.h> +#include <linux/err.h> +#include <linux/string.h> +#include <linux/list.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/hid.h> +#include <linux/mutex.h> + +#include <linux/i2c/i2c-hid.h> + +/* flags */ +#define I2C_HID_STARTED (1 << 0) +#define I2C_HID_RESET_PENDING (1 << 1) +#define I2C_HID_READ_PENDING (1 << 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) }; + +/* + * 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) }; + */ + +static DEFINE_MUTEX(i2c_hid_open_mut); + +/* 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 */ + char *inbuf; /* Input buffer */ + char *cmdbuf; /* Command buffer */ + char *argsbuf; /* Command arguments buffer */ + + unsigned long flags; /* device flags */ + + wait_queue_head_t wait; /* For waiting the interrupt */ +}; + +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) { + 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; +} + +static int i2c_hid_set_report(struct i2c_client *client, u8 reportType, + u8 reportID, unsigned char *buf, size_t data_len) +{ + struct i2c_hid *ihid = i2c_get_clientdata(client); + u8 *args = ihid->argsbuf; + int ret; + u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister); + + /* hidraw already checked that data_len < HID_MAX_BUFFER_SIZE */ + u16 size = 2 /* size */ + + (reportID ? 1 : 0) /* reportID */ + + data_len /* buf */; + int args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ + + 2 /* dataRegister */ + + size /* args */; + int index = 0; + + i2c_hid_dbg(ihid, "%s\n", __func__); + + if (reportID >= 0x0F) { + args[index++] = reportID; + reportID = 0x0F; + } + + args[index++] = dataRegister & 0xFF; + args[index++] = dataRegister >> 8; + + args[index++] = size & 0xFF; + args[index++] = size >> 8; + + if (reportID) + args[index++] = reportID; + + memcpy(&args[index], buf, data_len); + + ret = __i2c_hid_command(client, &hid_set_report_cmd, 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__); + + 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"); + + 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__); + + ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); + if (ret) + return ret; + + 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); + return ret; + } + + return 0; +} + +static void i2c_hid_get_input(struct i2c_hid *ihid) +{ + int ret, ret_size; + int size = le16_to_cpu(ihid->hdesc.wMaxInputLength); + + 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) { + 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; +} + +static void i2c_hid_init_report(struct hid_report *report, u8 *buffer, + size_t bufsize) +{ + struct hid_device *hid = report->device; + struct i2c_client *client = hid->driver_data; + struct i2c_hid *ihid = i2c_get_clientdata(client); + unsigned int size, ret_size; + + size = i2c_hid_get_report_length(report); + if (i2c_hid_get_report(client, + report->type == HID_FEATURE_REPORT ? 0x03 : 0x01, + report->id, buffer, size)) + return; + + i2c_hid_dbg(ihid, "report (len=%d): %*ph\n", size, size, ihid->inbuf); + + ret_size = buffer[0] | (buffer[1] << 8); + + if (ret_size != size) { + dev_err(&client->dev, "error in %s size:%d / ret_size:%d\n", + __func__, size, ret_size); + return; + } + + /* hid->driver_lock is held as we are in probe function, + * we just need to setup the input fields, so using + * hid_report_raw_event is safe. */ + hid_report_raw_event(hid, report->type, buffer + 2, size - 2, 1); +} + +/* + * Initialize all reports + */ +static void i2c_hid_init_reports(struct hid_device *hid) +{ + struct hid_report *report; + struct i2c_client *client = hid->driver_data; + struct i2c_hid *ihid = i2c_get_clientdata(client); + u8 *inbuf = kzalloc(ihid->bufsize, GFP_KERNEL); + + if (!inbuf) { + dev_err(&client->dev, "can not retrieve initial reports\n"); + return; + } + + list_for_each_entry(report, + &hid->report_enum[HID_INPUT_REPORT].report_list, list) + i2c_hid_init_report(report, inbuf, ihid->bufsize); + + list_for_each_entry(report, + &hid->report_enum[HID_FEATURE_REPORT].report_list, list) + i2c_hid_init_report(report, inbuf, ihid->bufsize); + + kfree(inbuf); +} + +/* + * 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->argsbuf); + kfree(ihid->cmdbuf); + ihid->inbuf = 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) + /* optional ReportID byte */ + sizeof(__u16) + /* data register */ + sizeof(__u16) + /* size of the report */ + report_size; /* report */ + + ihid->inbuf = 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->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->inbuf, ask_count); + + if (ret < 0) + return ret; + + ret_count = ihid->inbuf[0] | (ihid->inbuf[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->inbuf + 2, count); + + return count; +} + +static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf, + size_t count, unsigned char report_type) +{ + struct i2c_client *client = hid->driver_data; + int report_id = buf[0]; + + if (report_type == HID_INPUT_REPORT) + return -EINVAL; + + return i2c_hid_set_report(client, + report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, + report_id, buf, count); +} + +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; + + 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; + + 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); + 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) { + i2c_hid_free_buffers(ihid); + + ret = i2c_hid_alloc_buffers(ihid, bufsize); + + if (ret) + return ret; + } + + if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS)) + i2c_hid_init_reports(hid); + + return 0; +} + +static void i2c_hid_stop(struct hid_device *hid) +{ + struct i2c_client *client = hid->driver_data; + struct i2c_hid *ihid = i2c_get_clientdata(client); + + hid->claimed = 0; + + i2c_hid_free_buffers(ihid); +} + +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; + + mutex_lock(&i2c_hid_open_mut); + if (!hid->open++) { + ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); + if (ret) { + hid->open--; + goto done; + } + set_bit(I2C_HID_STARTED, &ihid->flags); + } +done: + mutex_unlock(&i2c_hid_open_mut); + return ret; +} + +static void i2c_hid_close(struct hid_device *hid) +{ + struct i2c_client *client = hid->driver_data; + struct i2c_hid *ihid = i2c_get_clientdata(client); + + /* protecting hid->open to make sure we don't restart + * data acquistion due to a resumption we no longer + * care about + */ + mutex_lock(&i2c_hid_open_mut); + if (!--hid->open) { + clear_bit(I2C_HID_STARTED, &ihid->flags); + + /* Save some power */ + i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); + } + mutex_unlock(&i2c_hid_open_mut); +} + +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); + int ret = 0; + + i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl); + + switch (lvl) { + case PM_HINT_FULLON: + ret = i2c_hid_set_power(client, I2C_HID_PWR_ON); + break; + case PM_HINT_NORMAL: + ret = i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); + break; + } + return ret; +} + +static int i2c_hid_hidinput_input_event(struct input_dev *dev, + unsigned int type, unsigned int code, int value) +{ + struct hid_device *hid = input_get_drvdata(dev); + struct hid_field *field; + int offset; + + if (type == EV_FF) + return input_ff_event(dev, type, code, value); + + if (type != EV_LED) + return -1; + + offset = hidinput_find_field(hid, type, code, &field); + + if (offset == -1) { + hid_warn(dev, "event field not found\n"); + return -1; + } + + return hid_set_field(field, offset, value); +} + +static 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, + .hidinput_input_event = i2c_hid_hidinput_input_event, +}; + +static int i2c_hid_init_irq(struct i2c_client *client) +{ + struct i2c_hid *ihid = i2c_get_clientdata(client); + int ret; + + dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq); + + ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, + IRQF_TRIGGER_FALLING | 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; + + /* Fetch the length of HID description, retrieve the 4 first bytes: + * bytes 0-1 -> length + * bytes 2-3 -> bcdVersion (has to be 1.00) */ + ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4); + + i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %*ph\n", + __func__, 4, ihid->hdesc_buffer); + + if (ret) { + dev_err(&client->dev, + "unable to fetch the size of HID descriptor (ret=%d)\n", + ret); + return -ENODEV; + } + + dsize = le16_to_cpu(hdesc->wHIDDescLength); + /* + * the size of the HID descriptor should at least contain + * its size and the bcdVersion (4 bytes), and should not be greater + * than sizeof(struct i2c_hid_desc) as we directly fill this struct + * through i2c_hid_command. + */ + if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) { + dev_err(&client->dev, "weird size of HID descriptor (%u)\n", + dsize); + return -ENODEV; + } + + /* 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; + } + + i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); + + ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, + dsize); + if (ret) { + dev_err(&client->dev, "hid_descr_cmd Fail\n"); + return -ENODEV; + } + + i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer); + + return 0; +} + +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 (!platform_data) { + dev_err(&client->dev, "HID register address not provided\n"); + return -EINVAL; + } + + if (!client->irq) { + dev_err(&client->dev, + "HID over i2c has not been provided an Int IRQ\n"); + return -EINVAL; + } + + ihid = kzalloc(sizeof(struct i2c_hid), GFP_KERNEL); + if (!ihid) + return -ENOMEM; + + i2c_set_clientdata(client, ihid); + + ihid->client = client; + + hidRegister = platform_data->hid_descriptor_address; + ihid->wHIDDescRegister = cpu_to_le16(hidRegister); + + init_waitqueue_head(&ihid->wait); + + /* 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; + + ret = i2c_hid_fetch_hid_descriptor(ihid); + if (ret < 0) + goto err; + + ret = i2c_hid_init_irq(client); + if (ret < 0) + goto err; + + 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->hid_get_raw_report = i2c_hid_get_raw_report; + hid->hid_output_raw_report = i2c_hid_output_raw_report; + 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); + + 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; + } + + return 0; + +err_mem_free: + hid_destroy_device(hid); + +err_irq: + free_irq(client->irq, ihid); + +err: + i2c_hid_free_buffers(ihid); + kfree(ihid); + return ret; +} + +static int i2c_hid_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); + + kfree(ihid); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int i2c_hid_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + + if (device_may_wakeup(&client->dev)) + enable_irq_wake(client->irq); + + /* Save some power */ + i2c_hid_set_power(client, I2C_HID_PWR_SLEEP); + + return 0; +} + +static int i2c_hid_resume(struct device *dev) +{ + int ret; + struct i2c_client *client = to_i2c_client(dev); + + ret = i2c_hid_hwreset(client); + if (ret) + return ret; + + if (device_may_wakeup(&client->dev)) + disable_irq_wake(client->irq); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(i2c_hid_pm, i2c_hid_suspend, i2c_hid_resume); + +static const struct i2c_device_id i2c_hid_id_table[] = { + { "hid", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table); + + +static struct i2c_driver i2c_hid_driver = { + .driver = { + .name = "i2c_hid", + .owner = THIS_MODULE, + .pm = &i2c_hid_pm, + }, + + .probe = i2c_hid_probe, + .remove = i2c_hid_remove, + + .id_table = i2c_hid_id_table, +}; + +module_i2c_driver(i2c_hid_driver); + +MODULE_DESCRIPTION("HID over I2C core driver"); +MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); +MODULE_LICENSE("GPL"); |