diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/hid/hid-cp2112.c | 1486 |
1 files changed, 1486 insertions, 0 deletions
diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c new file mode 100644 index 000000000..6f65f5257 --- /dev/null +++ b/drivers/hid/hid-cp2112.c @@ -0,0 +1,1486 @@ +/* + * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge + * Copyright (c) 2013,2014 Uplogix, Inc. + * David Barksdale <dbarksdale@uplogix.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +/* + * The Silicon Labs CP2112 chip is a USB HID device which provides an + * SMBus controller for talking to slave devices and 8 GPIO pins. The + * host communicates with the CP2112 via raw HID reports. + * + * Data Sheet: + * http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf + * Programming Interface Specification: + * https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf + */ + +#include <linux/gpio.h> +#include <linux/gpio/driver.h> +#include <linux/hid.h> +#include <linux/hidraw.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/nls.h> +#include <linux/usb/ch9.h> +#include "hid-ids.h" + +#define CP2112_REPORT_MAX_LENGTH 64 +#define CP2112_GPIO_CONFIG_LENGTH 5 +#define CP2112_GPIO_GET_LENGTH 2 +#define CP2112_GPIO_SET_LENGTH 3 + +enum { + CP2112_GPIO_CONFIG = 0x02, + CP2112_GPIO_GET = 0x03, + CP2112_GPIO_SET = 0x04, + CP2112_GET_VERSION_INFO = 0x05, + CP2112_SMBUS_CONFIG = 0x06, + CP2112_DATA_READ_REQUEST = 0x10, + CP2112_DATA_WRITE_READ_REQUEST = 0x11, + CP2112_DATA_READ_FORCE_SEND = 0x12, + CP2112_DATA_READ_RESPONSE = 0x13, + CP2112_DATA_WRITE_REQUEST = 0x14, + CP2112_TRANSFER_STATUS_REQUEST = 0x15, + CP2112_TRANSFER_STATUS_RESPONSE = 0x16, + CP2112_CANCEL_TRANSFER = 0x17, + CP2112_LOCK_BYTE = 0x20, + CP2112_USB_CONFIG = 0x21, + CP2112_MANUFACTURER_STRING = 0x22, + CP2112_PRODUCT_STRING = 0x23, + CP2112_SERIAL_STRING = 0x24, +}; + +enum { + STATUS0_IDLE = 0x00, + STATUS0_BUSY = 0x01, + STATUS0_COMPLETE = 0x02, + STATUS0_ERROR = 0x03, +}; + +enum { + STATUS1_TIMEOUT_NACK = 0x00, + STATUS1_TIMEOUT_BUS = 0x01, + STATUS1_ARBITRATION_LOST = 0x02, + STATUS1_READ_INCOMPLETE = 0x03, + STATUS1_WRITE_INCOMPLETE = 0x04, + STATUS1_SUCCESS = 0x05, +}; + +struct cp2112_smbus_config_report { + u8 report; /* CP2112_SMBUS_CONFIG */ + __be32 clock_speed; /* Hz */ + u8 device_address; /* Stored in the upper 7 bits */ + u8 auto_send_read; /* 1 = enabled, 0 = disabled */ + __be16 write_timeout; /* ms, 0 = no timeout */ + __be16 read_timeout; /* ms, 0 = no timeout */ + u8 scl_low_timeout; /* 1 = enabled, 0 = disabled */ + __be16 retry_time; /* # of retries, 0 = no limit */ +} __packed; + +struct cp2112_usb_config_report { + u8 report; /* CP2112_USB_CONFIG */ + __le16 vid; /* Vendor ID */ + __le16 pid; /* Product ID */ + u8 max_power; /* Power requested in 2mA units */ + u8 power_mode; /* 0x00 = bus powered + 0x01 = self powered & regulator off + 0x02 = self powered & regulator on */ + u8 release_major; + u8 release_minor; + u8 mask; /* What fields to program */ +} __packed; + +struct cp2112_read_req_report { + u8 report; /* CP2112_DATA_READ_REQUEST */ + u8 slave_address; + __be16 length; +} __packed; + +struct cp2112_write_read_req_report { + u8 report; /* CP2112_DATA_WRITE_READ_REQUEST */ + u8 slave_address; + __be16 length; + u8 target_address_length; + u8 target_address[16]; +} __packed; + +struct cp2112_write_req_report { + u8 report; /* CP2112_DATA_WRITE_REQUEST */ + u8 slave_address; + u8 length; + u8 data[61]; +} __packed; + +struct cp2112_force_read_report { + u8 report; /* CP2112_DATA_READ_FORCE_SEND */ + __be16 length; +} __packed; + +struct cp2112_xfer_status_report { + u8 report; /* CP2112_TRANSFER_STATUS_RESPONSE */ + u8 status0; /* STATUS0_* */ + u8 status1; /* STATUS1_* */ + __be16 retries; + __be16 length; +} __packed; + +struct cp2112_string_report { + u8 dummy; /* force .string to be aligned */ + u8 report; /* CP2112_*_STRING */ + u8 length; /* length in bytes of everyting after .report */ + u8 type; /* USB_DT_STRING */ + wchar_t string[30]; /* UTF16_LITTLE_ENDIAN string */ +} __packed; + +/* Number of times to request transfer status before giving up waiting for a + transfer to complete. This may need to be changed if SMBUS clock, retries, + or read/write/scl_low timeout settings are changed. */ +static const int XFER_STATUS_RETRIES = 10; + +/* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or + CP2112_TRANSFER_STATUS_RESPONSE. */ +static const int RESPONSE_TIMEOUT = 50; + +static const struct hid_device_id cp2112_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) }, + { } +}; +MODULE_DEVICE_TABLE(hid, cp2112_devices); + +struct cp2112_device { + struct i2c_adapter adap; + struct hid_device *hdev; + wait_queue_head_t wait; + u8 read_data[61]; + u8 read_length; + u8 hwversion; + int xfer_status; + atomic_t read_avail; + atomic_t xfer_avail; + struct gpio_chip gc; + u8 *in_out_buffer; + struct mutex lock; + + struct gpio_desc *desc[8]; + bool gpio_poll; + struct delayed_work gpio_poll_worker; + unsigned long irq_mask; + u8 gpio_prev_state; +}; + +static int gpio_push_pull = 0xFF; +module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask"); + +static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct cp2112_device *dev = gpiochip_get_data(chip); + struct hid_device *hdev = dev->hdev; + u8 *buf = dev->in_out_buffer; + int ret; + + mutex_lock(&dev->lock); + + ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, + CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT, + HID_REQ_GET_REPORT); + if (ret != CP2112_GPIO_CONFIG_LENGTH) { + hid_err(hdev, "error requesting GPIO config: %d\n", ret); + if (ret >= 0) + ret = -EIO; + goto exit; + } + + buf[1] &= ~(1 << offset); + buf[2] = gpio_push_pull; + + ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, + CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT, + HID_REQ_SET_REPORT); + if (ret != CP2112_GPIO_CONFIG_LENGTH) { + hid_err(hdev, "error setting GPIO config: %d\n", ret); + if (ret >= 0) + ret = -EIO; + goto exit; + } + + ret = 0; + +exit: + mutex_unlock(&dev->lock); + return ret; +} + +static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct cp2112_device *dev = gpiochip_get_data(chip); + struct hid_device *hdev = dev->hdev; + u8 *buf = dev->in_out_buffer; + int ret; + + mutex_lock(&dev->lock); + + buf[0] = CP2112_GPIO_SET; + buf[1] = value ? 0xff : 0; + buf[2] = 1 << offset; + + ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, + CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT, + HID_REQ_SET_REPORT); + if (ret < 0) + hid_err(hdev, "error setting GPIO values: %d\n", ret); + + mutex_unlock(&dev->lock); +} + +static int cp2112_gpio_get_all(struct gpio_chip *chip) +{ + struct cp2112_device *dev = gpiochip_get_data(chip); + struct hid_device *hdev = dev->hdev; + u8 *buf = dev->in_out_buffer; + int ret; + + mutex_lock(&dev->lock); + + ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, + CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT, + HID_REQ_GET_REPORT); + if (ret != CP2112_GPIO_GET_LENGTH) { + hid_err(hdev, "error requesting GPIO values: %d\n", ret); + ret = ret < 0 ? ret : -EIO; + goto exit; + } + + ret = buf[1]; + +exit: + mutex_unlock(&dev->lock); + + return ret; +} + +static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + int ret; + + ret = cp2112_gpio_get_all(chip); + if (ret < 0) + return ret; + + return (ret >> offset) & 1; +} + +static int cp2112_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct cp2112_device *dev = gpiochip_get_data(chip); + struct hid_device *hdev = dev->hdev; + u8 *buf = dev->in_out_buffer; + int ret; + + mutex_lock(&dev->lock); + + ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, + CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT, + HID_REQ_GET_REPORT); + if (ret != CP2112_GPIO_CONFIG_LENGTH) { + hid_err(hdev, "error requesting GPIO config: %d\n", ret); + goto fail; + } + + buf[1] |= 1 << offset; + buf[2] = gpio_push_pull; + + ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, + CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT, + HID_REQ_SET_REPORT); + if (ret < 0) { + hid_err(hdev, "error setting GPIO config: %d\n", ret); + goto fail; + } + + mutex_unlock(&dev->lock); + + /* + * Set gpio value when output direction is already set, + * as specified in AN495, Rev. 0.2, cpt. 4.4 + */ + cp2112_gpio_set(chip, offset, value); + + return 0; + +fail: + mutex_unlock(&dev->lock); + return ret < 0 ? ret : -EIO; +} + +static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number, + u8 *data, size_t count, unsigned char report_type) +{ + u8 *buf; + int ret; + + buf = kmalloc(count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + ret = hid_hw_raw_request(hdev, report_number, buf, count, + report_type, HID_REQ_GET_REPORT); + memcpy(data, buf, count); + kfree(buf); + return ret; +} + +static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count, + unsigned char report_type) +{ + u8 *buf; + int ret; + + buf = kmemdup(data, count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (report_type == HID_OUTPUT_REPORT) + ret = hid_hw_output_report(hdev, buf, count); + else + ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type, + HID_REQ_SET_REPORT); + + kfree(buf); + return ret; +} + +static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail) +{ + int ret = 0; + + /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a + * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to + * come in cp2112_raw_event or timeout. There will only be one of these + * in flight at any one time. The timeout is extremely large and is a + * last resort if the CP2112 has died. If we do timeout we don't expect + * to receive the response which would cause data races, it's not like + * we can do anything about it anyway. + */ + ret = wait_event_interruptible_timeout(dev->wait, + atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT)); + if (-ERESTARTSYS == ret) + return ret; + if (!ret) + return -ETIMEDOUT; + + atomic_set(avail, 0); + return 0; +} + +static int cp2112_xfer_status(struct cp2112_device *dev) +{ + struct hid_device *hdev = dev->hdev; + u8 buf[2]; + int ret; + + buf[0] = CP2112_TRANSFER_STATUS_REQUEST; + buf[1] = 0x01; + atomic_set(&dev->xfer_avail, 0); + + ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); + if (ret < 0) { + hid_warn(hdev, "Error requesting status: %d\n", ret); + return ret; + } + + ret = cp2112_wait(dev, &dev->xfer_avail); + if (ret) + return ret; + + return dev->xfer_status; +} + +static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size) +{ + struct hid_device *hdev = dev->hdev; + struct cp2112_force_read_report report; + int ret; + + if (size > sizeof(dev->read_data)) + size = sizeof(dev->read_data); + report.report = CP2112_DATA_READ_FORCE_SEND; + report.length = cpu_to_be16(size); + + atomic_set(&dev->read_avail, 0); + + ret = cp2112_hid_output(hdev, &report.report, sizeof(report), + HID_OUTPUT_REPORT); + if (ret < 0) { + hid_warn(hdev, "Error requesting data: %d\n", ret); + return ret; + } + + ret = cp2112_wait(dev, &dev->read_avail); + if (ret) + return ret; + + hid_dbg(hdev, "read %d of %zd bytes requested\n", + dev->read_length, size); + + if (size > dev->read_length) + size = dev->read_length; + + memcpy(data, dev->read_data, size); + return dev->read_length; +} + +static int cp2112_read_req(void *buf, u8 slave_address, u16 length) +{ + struct cp2112_read_req_report *report = buf; + + if (length < 1 || length > 512) + return -EINVAL; + + report->report = CP2112_DATA_READ_REQUEST; + report->slave_address = slave_address << 1; + report->length = cpu_to_be16(length); + return sizeof(*report); +} + +static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length, + u8 command, u8 *data, u8 data_length) +{ + struct cp2112_write_read_req_report *report = buf; + + if (length < 1 || length > 512 + || data_length > sizeof(report->target_address) - 1) + return -EINVAL; + + report->report = CP2112_DATA_WRITE_READ_REQUEST; + report->slave_address = slave_address << 1; + report->length = cpu_to_be16(length); + report->target_address_length = data_length + 1; + report->target_address[0] = command; + memcpy(&report->target_address[1], data, data_length); + return data_length + 6; +} + +static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data, + u8 data_length) +{ + struct cp2112_write_req_report *report = buf; + + if (data_length > sizeof(report->data) - 1) + return -EINVAL; + + report->report = CP2112_DATA_WRITE_REQUEST; + report->slave_address = slave_address << 1; + report->length = data_length + 1; + report->data[0] = command; + memcpy(&report->data[1], data, data_length); + return data_length + 4; +} + +static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data, + u8 data_length) +{ + struct cp2112_write_req_report *report = buf; + + if (data_length > sizeof(report->data)) + return -EINVAL; + + report->report = CP2112_DATA_WRITE_REQUEST; + report->slave_address = slave_address << 1; + report->length = data_length; + memcpy(report->data, data, data_length); + return data_length + 3; +} + +static int cp2112_i2c_write_read_req(void *buf, u8 slave_address, + u8 *addr, int addr_length, + int read_length) +{ + struct cp2112_write_read_req_report *report = buf; + + if (read_length < 1 || read_length > 512 || + addr_length > sizeof(report->target_address)) + return -EINVAL; + + report->report = CP2112_DATA_WRITE_READ_REQUEST; + report->slave_address = slave_address << 1; + report->length = cpu_to_be16(read_length); + report->target_address_length = addr_length; + memcpy(report->target_address, addr, addr_length); + return addr_length + 5; +} + +static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; + struct hid_device *hdev = dev->hdev; + u8 buf[64]; + ssize_t count; + ssize_t read_length = 0; + u8 *read_buf = NULL; + unsigned int retries; + int ret; + + hid_dbg(hdev, "I2C %d messages\n", num); + + if (num == 1) { + if (msgs->flags & I2C_M_RD) { + hid_dbg(hdev, "I2C read %#04x len %d\n", + msgs->addr, msgs->len); + read_length = msgs->len; + read_buf = msgs->buf; + count = cp2112_read_req(buf, msgs->addr, msgs->len); + } else { + hid_dbg(hdev, "I2C write %#04x len %d\n", + msgs->addr, msgs->len); + count = cp2112_i2c_write_req(buf, msgs->addr, + msgs->buf, msgs->len); + } + if (count < 0) + return count; + } else if (dev->hwversion > 1 && /* no repeated start in rev 1 */ + num == 2 && + msgs[0].addr == msgs[1].addr && + !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) { + hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n", + msgs[0].addr, msgs[0].len, msgs[1].len); + read_length = msgs[1].len; + read_buf = msgs[1].buf; + count = cp2112_i2c_write_read_req(buf, msgs[0].addr, + msgs[0].buf, msgs[0].len, msgs[1].len); + if (count < 0) + return count; + } else { + hid_err(hdev, + "Multi-message I2C transactions not supported\n"); + return -EOPNOTSUPP; + } + + ret = hid_hw_power(hdev, PM_HINT_FULLON); + if (ret < 0) { + hid_err(hdev, "power management error: %d\n", ret); + return ret; + } + + ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); + if (ret < 0) { + hid_warn(hdev, "Error starting transaction: %d\n", ret); + goto power_normal; + } + + for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { + ret = cp2112_xfer_status(dev); + if (-EBUSY == ret) + continue; + if (ret < 0) + goto power_normal; + break; + } + + if (XFER_STATUS_RETRIES <= retries) { + hid_warn(hdev, "Transfer timed out, cancelling.\n"); + buf[0] = CP2112_CANCEL_TRANSFER; + buf[1] = 0x01; + + ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); + if (ret < 0) + hid_warn(hdev, "Error cancelling transaction: %d\n", + ret); + + ret = -ETIMEDOUT; + goto power_normal; + } + + for (count = 0; count < read_length;) { + ret = cp2112_read(dev, read_buf + count, read_length - count); + if (ret < 0) + goto power_normal; + if (ret == 0) { + hid_err(hdev, "read returned 0\n"); + ret = -EIO; + goto power_normal; + } + count += ret; + if (count > read_length) { + /* + * The hardware returned too much data. + * This is mostly harmless because cp2112_read() + * has a limit check so didn't overrun our + * buffer. Nevertheless, we return an error + * because something is seriously wrong and + * it shouldn't go unnoticed. + */ + hid_err(hdev, "long read: %d > %zd\n", + ret, read_length - count + ret); + ret = -EIO; + goto power_normal; + } + } + + /* return the number of transferred messages */ + ret = num; + +power_normal: + hid_hw_power(hdev, PM_HINT_NORMAL); + hid_dbg(hdev, "I2C transfer finished: %d\n", ret); + return ret; +} + +static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, + unsigned short flags, char read_write, u8 command, + int size, union i2c_smbus_data *data) +{ + struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; + struct hid_device *hdev = dev->hdev; + u8 buf[64]; + __le16 word; + ssize_t count; + size_t read_length = 0; + unsigned int retries; + int ret; + + hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n", + read_write == I2C_SMBUS_WRITE ? "write" : "read", + addr, flags, command, size); + + switch (size) { + case I2C_SMBUS_BYTE: + read_length = 1; + + if (I2C_SMBUS_READ == read_write) + count = cp2112_read_req(buf, addr, read_length); + else + count = cp2112_write_req(buf, addr, command, NULL, + 0); + break; + case I2C_SMBUS_BYTE_DATA: + read_length = 1; + + if (I2C_SMBUS_READ == read_write) + count = cp2112_write_read_req(buf, addr, read_length, + command, NULL, 0); + else + count = cp2112_write_req(buf, addr, command, + &data->byte, 1); + break; + case I2C_SMBUS_WORD_DATA: + read_length = 2; + word = cpu_to_le16(data->word); + + if (I2C_SMBUS_READ == read_write) + count = cp2112_write_read_req(buf, addr, read_length, + command, NULL, 0); + else + count = cp2112_write_req(buf, addr, command, + (u8 *)&word, 2); + break; + case I2C_SMBUS_PROC_CALL: + size = I2C_SMBUS_WORD_DATA; + read_write = I2C_SMBUS_READ; + read_length = 2; + word = cpu_to_le16(data->word); + + count = cp2112_write_read_req(buf, addr, read_length, command, + (u8 *)&word, 2); + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + if (read_write == I2C_SMBUS_READ) { + read_length = data->block[0]; + count = cp2112_write_read_req(buf, addr, read_length, + command, NULL, 0); + } else { + count = cp2112_write_req(buf, addr, command, + data->block + 1, + data->block[0]); + } + break; + case I2C_SMBUS_BLOCK_DATA: + if (I2C_SMBUS_READ == read_write) { + count = cp2112_write_read_req(buf, addr, + I2C_SMBUS_BLOCK_MAX, + command, NULL, 0); + } else { + count = cp2112_write_req(buf, addr, command, + data->block, + data->block[0] + 1); + } + break; + case I2C_SMBUS_BLOCK_PROC_CALL: + size = I2C_SMBUS_BLOCK_DATA; + read_write = I2C_SMBUS_READ; + + count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX, + command, data->block, + data->block[0] + 1); + break; + default: + hid_warn(hdev, "Unsupported transaction %d\n", size); + return -EOPNOTSUPP; + } + + if (count < 0) + return count; + + ret = hid_hw_power(hdev, PM_HINT_FULLON); + if (ret < 0) { + hid_err(hdev, "power management error: %d\n", ret); + return ret; + } + + ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); + if (ret < 0) { + hid_warn(hdev, "Error starting transaction: %d\n", ret); + goto power_normal; + } + + for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { + ret = cp2112_xfer_status(dev); + if (-EBUSY == ret) + continue; + if (ret < 0) + goto power_normal; + break; + } + + if (XFER_STATUS_RETRIES <= retries) { + hid_warn(hdev, "Transfer timed out, cancelling.\n"); + buf[0] = CP2112_CANCEL_TRANSFER; + buf[1] = 0x01; + + ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); + if (ret < 0) + hid_warn(hdev, "Error cancelling transaction: %d\n", + ret); + + ret = -ETIMEDOUT; + goto power_normal; + } + + if (I2C_SMBUS_WRITE == read_write) { + ret = 0; + goto power_normal; + } + + if (I2C_SMBUS_BLOCK_DATA == size) + read_length = ret; + + ret = cp2112_read(dev, buf, read_length); + if (ret < 0) + goto power_normal; + if (ret != read_length) { + hid_warn(hdev, "short read: %d < %zd\n", ret, read_length); + ret = -EIO; + goto power_normal; + } + + switch (size) { + case I2C_SMBUS_BYTE: + case I2C_SMBUS_BYTE_DATA: + data->byte = buf[0]; + break; + case I2C_SMBUS_WORD_DATA: + data->word = le16_to_cpup((__le16 *)buf); + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + memcpy(data->block + 1, buf, read_length); + break; + case I2C_SMBUS_BLOCK_DATA: + if (read_length > I2C_SMBUS_BLOCK_MAX) { + ret = -EPROTO; + goto power_normal; + } + + memcpy(data->block, buf, read_length); + break; + } + + ret = 0; +power_normal: + hid_hw_power(hdev, PM_HINT_NORMAL); + hid_dbg(hdev, "transfer finished: %d\n", ret); + return ret; +} + +static u32 cp2112_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | + I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_BLOCK_DATA | + I2C_FUNC_SMBUS_I2C_BLOCK | + I2C_FUNC_SMBUS_PROC_CALL | + I2C_FUNC_SMBUS_BLOCK_PROC_CALL; +} + +static const struct i2c_algorithm smbus_algorithm = { + .master_xfer = cp2112_i2c_xfer, + .smbus_xfer = cp2112_xfer, + .functionality = cp2112_functionality, +}; + +static int cp2112_get_usb_config(struct hid_device *hdev, + struct cp2112_usb_config_report *cfg) +{ + int ret; + + ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg), + HID_FEATURE_REPORT); + if (ret != sizeof(*cfg)) { + hid_err(hdev, "error reading usb config: %d\n", ret); + if (ret < 0) + return ret; + return -EIO; + } + + return 0; +} + +static int cp2112_set_usb_config(struct hid_device *hdev, + struct cp2112_usb_config_report *cfg) +{ + int ret; + + BUG_ON(cfg->report != CP2112_USB_CONFIG); + + ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg), + HID_FEATURE_REPORT); + if (ret != sizeof(*cfg)) { + hid_err(hdev, "error writing usb config: %d\n", ret); + if (ret < 0) + return ret; + return -EIO; + } + + return 0; +} + +static void chmod_sysfs_attrs(struct hid_device *hdev); + +#define CP2112_CONFIG_ATTR(name, store, format, ...) \ +static ssize_t name##_store(struct device *kdev, \ + struct device_attribute *attr, const char *buf, \ + size_t count) \ +{ \ + struct hid_device *hdev = to_hid_device(kdev); \ + struct cp2112_usb_config_report cfg; \ + int ret = cp2112_get_usb_config(hdev, &cfg); \ + if (ret) \ + return ret; \ + store; \ + ret = cp2112_set_usb_config(hdev, &cfg); \ + if (ret) \ + return ret; \ + chmod_sysfs_attrs(hdev); \ + return count; \ +} \ +static ssize_t name##_show(struct device *kdev, \ + struct device_attribute *attr, char *buf) \ +{ \ + struct hid_device *hdev = to_hid_device(kdev); \ + struct cp2112_usb_config_report cfg; \ + int ret = cp2112_get_usb_config(hdev, &cfg); \ + if (ret) \ + return ret; \ + return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \ +} \ +static DEVICE_ATTR_RW(name); + +CP2112_CONFIG_ATTR(vendor_id, ({ + u16 vid; + + if (sscanf(buf, "%hi", &vid) != 1) + return -EINVAL; + + cfg.vid = cpu_to_le16(vid); + cfg.mask = 0x01; +}), "0x%04x\n", le16_to_cpu(cfg.vid)); + +CP2112_CONFIG_ATTR(product_id, ({ + u16 pid; + + if (sscanf(buf, "%hi", &pid) != 1) + return -EINVAL; + + cfg.pid = cpu_to_le16(pid); + cfg.mask = 0x02; +}), "0x%04x\n", le16_to_cpu(cfg.pid)); + +CP2112_CONFIG_ATTR(max_power, ({ + int mA; + + if (sscanf(buf, "%i", &mA) != 1) + return -EINVAL; + + cfg.max_power = (mA + 1) / 2; + cfg.mask = 0x04; +}), "%u mA\n", cfg.max_power * 2); + +CP2112_CONFIG_ATTR(power_mode, ({ + if (sscanf(buf, "%hhi", &cfg.power_mode) != 1) + return -EINVAL; + + cfg.mask = 0x08; +}), "%u\n", cfg.power_mode); + +CP2112_CONFIG_ATTR(release_version, ({ + if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor) + != 2) + return -EINVAL; + + cfg.mask = 0x10; +}), "%u.%u\n", cfg.release_major, cfg.release_minor); + +#undef CP2112_CONFIG_ATTR + +struct cp2112_pstring_attribute { + struct device_attribute attr; + unsigned char report; +}; + +static ssize_t pstr_store(struct device *kdev, + struct device_attribute *kattr, const char *buf, + size_t count) +{ + struct hid_device *hdev = to_hid_device(kdev); + struct cp2112_pstring_attribute *attr = + container_of(kattr, struct cp2112_pstring_attribute, attr); + struct cp2112_string_report report; + int ret; + + memset(&report, 0, sizeof(report)); + + ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN, + report.string, ARRAY_SIZE(report.string)); + report.report = attr->report; + report.length = ret * sizeof(report.string[0]) + 2; + report.type = USB_DT_STRING; + + ret = cp2112_hid_output(hdev, &report.report, report.length + 1, + HID_FEATURE_REPORT); + if (ret != report.length + 1) { + hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name, + ret); + if (ret < 0) + return ret; + return -EIO; + } + + chmod_sysfs_attrs(hdev); + return count; +} + +static ssize_t pstr_show(struct device *kdev, + struct device_attribute *kattr, char *buf) +{ + struct hid_device *hdev = to_hid_device(kdev); + struct cp2112_pstring_attribute *attr = + container_of(kattr, struct cp2112_pstring_attribute, attr); + struct cp2112_string_report report; + u8 length; + int ret; + + ret = cp2112_hid_get(hdev, attr->report, &report.report, + sizeof(report) - 1, HID_FEATURE_REPORT); + if (ret < 3) { + hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name, + ret); + if (ret < 0) + return ret; + return -EIO; + } + + if (report.length < 2) { + hid_err(hdev, "invalid %s string length: %d\n", + kattr->attr.name, report.length); + return -EIO; + } + + length = report.length > ret - 1 ? ret - 1 : report.length; + length = (length - 2) / sizeof(report.string[0]); + ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf, + PAGE_SIZE - 1); + buf[ret++] = '\n'; + return ret; +} + +#define CP2112_PSTR_ATTR(name, _report) \ +static struct cp2112_pstring_attribute dev_attr_##name = { \ + .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \ + .report = _report, \ +}; + +CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING); +CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING); +CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING); + +#undef CP2112_PSTR_ATTR + +static const struct attribute_group cp2112_attr_group = { + .attrs = (struct attribute *[]){ + &dev_attr_vendor_id.attr, + &dev_attr_product_id.attr, + &dev_attr_max_power.attr, + &dev_attr_power_mode.attr, + &dev_attr_release_version.attr, + &dev_attr_manufacturer.attr.attr, + &dev_attr_product.attr.attr, + &dev_attr_serial.attr.attr, + NULL + } +}; + +/* Chmoding our sysfs attributes is simply a way to expose which fields in the + * PROM have already been programmed. We do not depend on this preventing + * writing to these attributes since the CP2112 will simply ignore writes to + * already-programmed fields. This is why there is no sense in fixing this + * racy behaviour. + */ +static void chmod_sysfs_attrs(struct hid_device *hdev) +{ + struct attribute **attr; + u8 buf[2]; + int ret; + + ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf), + HID_FEATURE_REPORT); + if (ret != sizeof(buf)) { + hid_err(hdev, "error reading lock byte: %d\n", ret); + return; + } + + for (attr = cp2112_attr_group.attrs; *attr; ++attr) { + umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO; + ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode); + if (ret < 0) + hid_err(hdev, "error chmoding sysfs file %s\n", + (*attr)->name); + buf[1] >>= 1; + } +} + +static void cp2112_gpio_irq_ack(struct irq_data *d) +{ +} + +static void cp2112_gpio_irq_mask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + __clear_bit(d->hwirq, &dev->irq_mask); +} + +static void cp2112_gpio_irq_unmask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + __set_bit(d->hwirq, &dev->irq_mask); +} + +static void cp2112_gpio_poll_callback(struct work_struct *work) +{ + struct cp2112_device *dev = container_of(work, struct cp2112_device, + gpio_poll_worker.work); + struct irq_data *d; + u8 gpio_mask; + u8 virqs = (u8)dev->irq_mask; + u32 irq_type; + int irq, virq, ret; + + ret = cp2112_gpio_get_all(&dev->gc); + if (ret == -ENODEV) /* the hardware has been disconnected */ + return; + if (ret < 0) + goto exit; + + gpio_mask = ret; + + while (virqs) { + virq = ffs(virqs) - 1; + virqs &= ~BIT(virq); + + if (!dev->gc.to_irq) + break; + + irq = dev->gc.to_irq(&dev->gc, virq); + + d = irq_get_irq_data(irq); + if (!d) + continue; + + irq_type = irqd_get_trigger_type(d); + + if (gpio_mask & BIT(virq)) { + /* Level High */ + + if (irq_type & IRQ_TYPE_LEVEL_HIGH) + handle_nested_irq(irq); + + if ((irq_type & IRQ_TYPE_EDGE_RISING) && + !(dev->gpio_prev_state & BIT(virq))) + handle_nested_irq(irq); + } else { + /* Level Low */ + + if (irq_type & IRQ_TYPE_LEVEL_LOW) + handle_nested_irq(irq); + + if ((irq_type & IRQ_TYPE_EDGE_FALLING) && + (dev->gpio_prev_state & BIT(virq))) + handle_nested_irq(irq); + } + } + + dev->gpio_prev_state = gpio_mask; + +exit: + if (dev->gpio_poll) + schedule_delayed_work(&dev->gpio_poll_worker, 10); +} + + +static unsigned int cp2112_gpio_irq_startup(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback); + + if (!dev->gpio_poll) { + dev->gpio_poll = true; + schedule_delayed_work(&dev->gpio_poll_worker, 0); + } + + cp2112_gpio_irq_unmask(d); + return 0; +} + +static void cp2112_gpio_irq_shutdown(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct cp2112_device *dev = gpiochip_get_data(gc); + + cancel_delayed_work_sync(&dev->gpio_poll_worker); +} + +static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type) +{ + return 0; +} + +static struct irq_chip cp2112_gpio_irqchip = { + .name = "cp2112-gpio", + .irq_startup = cp2112_gpio_irq_startup, + .irq_shutdown = cp2112_gpio_irq_shutdown, + .irq_ack = cp2112_gpio_irq_ack, + .irq_mask = cp2112_gpio_irq_mask, + .irq_unmask = cp2112_gpio_irq_unmask, + .irq_set_type = cp2112_gpio_irq_type, +}; + +static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev, + int pin) +{ + int ret; + + if (dev->desc[pin]) + return -EINVAL; + + dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin, + "HID/I2C:Event"); + if (IS_ERR(dev->desc[pin])) { + dev_err(dev->gc.parent, "Failed to request GPIO\n"); + return PTR_ERR(dev->desc[pin]); + } + + ret = cp2112_gpio_direction_input(&dev->gc, pin); + if (ret < 0) { + dev_err(dev->gc.parent, "Failed to set GPIO to input dir\n"); + goto err_desc; + } + + ret = gpiochip_lock_as_irq(&dev->gc, pin); + if (ret) { + dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n"); + goto err_desc; + } + + ret = gpiod_to_irq(dev->desc[pin]); + if (ret < 0) { + dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n"); + goto err_lock; + } + + return ret; + +err_lock: + gpiochip_unlock_as_irq(&dev->gc, pin); +err_desc: + gpiochip_free_own_desc(dev->desc[pin]); + dev->desc[pin] = NULL; + return ret; +} + +static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) +{ + struct cp2112_device *dev; + u8 buf[3]; + struct cp2112_smbus_config_report config; + int ret; + + dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH, + GFP_KERNEL); + if (!dev->in_out_buffer) + return -ENOMEM; + + mutex_init(&dev->lock); + + ret = hid_parse(hdev); + if (ret) { + hid_err(hdev, "parse failed\n"); + return ret; + } + + ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); + if (ret) { + hid_err(hdev, "hw start failed\n"); + return ret; + } + + ret = hid_hw_open(hdev); + if (ret) { + hid_err(hdev, "hw open failed\n"); + goto err_hid_stop; + } + + ret = hid_hw_power(hdev, PM_HINT_FULLON); + if (ret < 0) { + hid_err(hdev, "power management error: %d\n", ret); + goto err_hid_close; + } + + ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf), + HID_FEATURE_REPORT); + if (ret != sizeof(buf)) { + hid_err(hdev, "error requesting version\n"); + if (ret >= 0) + ret = -EIO; + goto err_power_normal; + } + + hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n", + buf[1], buf[2]); + + ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config, + sizeof(config), HID_FEATURE_REPORT); + if (ret != sizeof(config)) { + hid_err(hdev, "error requesting SMBus config\n"); + if (ret >= 0) + ret = -EIO; + goto err_power_normal; + } + + config.retry_time = cpu_to_be16(1); + + ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config), + HID_FEATURE_REPORT); + if (ret != sizeof(config)) { + hid_err(hdev, "error setting SMBus config\n"); + if (ret >= 0) + ret = -EIO; + goto err_power_normal; + } + + hid_set_drvdata(hdev, (void *)dev); + dev->hdev = hdev; + dev->adap.owner = THIS_MODULE; + dev->adap.class = I2C_CLASS_HWMON; + dev->adap.algo = &smbus_algorithm; + dev->adap.algo_data = dev; + dev->adap.dev.parent = &hdev->dev; + snprintf(dev->adap.name, sizeof(dev->adap.name), + "CP2112 SMBus Bridge on hidraw%d", + ((struct hidraw *)hdev->hidraw)->minor); + dev->hwversion = buf[2]; + init_waitqueue_head(&dev->wait); + + hid_device_io_start(hdev); + ret = i2c_add_adapter(&dev->adap); + hid_device_io_stop(hdev); + + if (ret) { + hid_err(hdev, "error registering i2c adapter\n"); + goto err_power_normal; + } + + hid_dbg(hdev, "adapter registered\n"); + + dev->gc.label = "cp2112_gpio"; + dev->gc.direction_input = cp2112_gpio_direction_input; + dev->gc.direction_output = cp2112_gpio_direction_output; + dev->gc.set = cp2112_gpio_set; + dev->gc.get = cp2112_gpio_get; + dev->gc.base = -1; + dev->gc.ngpio = 8; + dev->gc.can_sleep = 1; + dev->gc.parent = &hdev->dev; + + ret = gpiochip_add_data(&dev->gc, dev); + if (ret < 0) { + hid_err(hdev, "error registering gpio chip\n"); + goto err_free_i2c; + } + + ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group); + if (ret < 0) { + hid_err(hdev, "error creating sysfs attrs\n"); + goto err_gpiochip_remove; + } + + chmod_sysfs_attrs(hdev); + hid_hw_power(hdev, PM_HINT_NORMAL); + + ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0, + handle_simple_irq, IRQ_TYPE_NONE); + if (ret) { + dev_err(dev->gc.parent, "failed to add IRQ chip\n"); + goto err_sysfs_remove; + } + + return ret; + +err_sysfs_remove: + sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group); +err_gpiochip_remove: + gpiochip_remove(&dev->gc); +err_free_i2c: + i2c_del_adapter(&dev->adap); +err_power_normal: + hid_hw_power(hdev, PM_HINT_NORMAL); +err_hid_close: + hid_hw_close(hdev); +err_hid_stop: + hid_hw_stop(hdev); + return ret; +} + +static void cp2112_remove(struct hid_device *hdev) +{ + struct cp2112_device *dev = hid_get_drvdata(hdev); + int i; + + sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group); + i2c_del_adapter(&dev->adap); + + if (dev->gpio_poll) { + dev->gpio_poll = false; + cancel_delayed_work_sync(&dev->gpio_poll_worker); + } + + for (i = 0; i < ARRAY_SIZE(dev->desc); i++) { + gpiochip_unlock_as_irq(&dev->gc, i); + gpiochip_free_own_desc(dev->desc[i]); + } + + gpiochip_remove(&dev->gc); + /* i2c_del_adapter has finished removing all i2c devices from our + * adapter. Well behaved devices should no longer call our cp2112_xfer + * and should have waited for any pending calls to finish. It has also + * waited for device_unregister(&adap->dev) to complete. Therefore we + * can safely free our struct cp2112_device. + */ + hid_hw_close(hdev); + hid_hw_stop(hdev); +} + +static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report, + u8 *data, int size) +{ + struct cp2112_device *dev = hid_get_drvdata(hdev); + struct cp2112_xfer_status_report *xfer = (void *)data; + + switch (data[0]) { + case CP2112_TRANSFER_STATUS_RESPONSE: + hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n", + xfer->status0, xfer->status1, + be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length)); + + switch (xfer->status0) { + case STATUS0_IDLE: + dev->xfer_status = -EAGAIN; + break; + case STATUS0_BUSY: + dev->xfer_status = -EBUSY; + break; + case STATUS0_COMPLETE: + dev->xfer_status = be16_to_cpu(xfer->length); + break; + case STATUS0_ERROR: + switch (xfer->status1) { + case STATUS1_TIMEOUT_NACK: + case STATUS1_TIMEOUT_BUS: + dev->xfer_status = -ETIMEDOUT; + break; + default: + dev->xfer_status = -EIO; + break; + } + break; + default: + dev->xfer_status = -EINVAL; + break; + } + + atomic_set(&dev->xfer_avail, 1); + break; + case CP2112_DATA_READ_RESPONSE: + hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]); + + dev->read_length = data[2]; + if (dev->read_length > sizeof(dev->read_data)) + dev->read_length = sizeof(dev->read_data); + + memcpy(dev->read_data, &data[3], dev->read_length); + atomic_set(&dev->read_avail, 1); + break; + default: + hid_err(hdev, "unknown report\n"); + + return 0; + } + + wake_up_interruptible(&dev->wait); + return 1; +} + +static struct hid_driver cp2112_driver = { + .name = "cp2112", + .id_table = cp2112_devices, + .probe = cp2112_probe, + .remove = cp2112_remove, + .raw_event = cp2112_raw_event, +}; + +module_hid_driver(cp2112_driver); +MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge"); +MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>"); +MODULE_LICENSE("GPL"); + |