linux/drivers/hid/hid-cp2112.c
Linus Torvalds 58cf279aca GPIO bulk updates for the v4.5 kernel cycle:
Infrastructural changes:
 
 - In struct gpio_chip, rename the .dev node to .parent to better reflect
   the fact that this is not the GPIO struct device abstraction. We will
   add that soon so this would be totallt confusing.
 
 - It was noted that the driver .get_value() callbacks was
   sometimes reporting negative -ERR values to the gpiolib core, expecting
   them to be propagated to consumer gpiod_get_value() and gpio_get_value()
   calls. This was not happening, so as there was a mess of drivers
   returning negative errors and some returning "anything else than zero"
   to indicate that a line was active. As some would have bit 31 set to
   indicate "line active" it clashed with negative error codes. This is
   fixed by the largeish series clamping values in all drivers with
   !!value to [0,1] and then augmenting the code to propagate error codes
   to consumers. (Includes some ACKed patches in other subsystems.)
 
 - Add a void *data pointer to struct gpio_chip. The container_of() design
   pattern is indeed very nice, but we want to reform the struct gpio_chip
   to be a non-volative, stateless business, and keep states internal to
   the gpiolib to be able to hold on to the state when adding a proper
   userspace ABI (character device) further down the road. To achieve this,
   drivers need a handle at the internal state that is not dependent on
   their struct gpio_chip() so we add gpiochip_add_data() and
   gpiochip_get_data() following the pattern of many other subsystems.
   All the "use gpiochip data pointer" patches transforms drivers to this
   scheme.
 
 - The Generic GPIO chip header has been merged into the general
   <linux/gpio/driver.h> header, and the custom header for that removed.
   Instead of having a separate mm_gpio_chip struct for these generic
   drivers, merge that into struct gpio_chip, simplifying the code and
   removing the need for separate and confusing includes.
 
 Misc improvements:
 
 - Stabilize the way GPIOs are looked up from the ACPI legacy
   specification.
 
 - Incremental driver features for PXA, PCA953X, Lantiq (patches from the
   OpenWRT community), RCAR, Zynq, PL061, 104-idi-48
 
 New drivers:
 
 - Add a GPIO chip to the ALSA SoC AC97 driver.
 
 - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir, but
   the branch is merged here too to account for infrastructural changes).
 
 - The sx150x driver now supports the sx1502.
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Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "Here is the bulk of GPIO changes for v4.5.

  Notably there are big refactorings mostly by myself, aimed at getting
  the gpio_chip into a shape that makes me believe I can proceed to
  preserve state for a proper userspace ABI (character device) that has
  already been proposed once, but resulted in the feedback that I need
  to go back and restructure stuff.  So I've been restructuring stuff.
  On the way I ran into brokenness (return code from the get_value()
  callback) and had to fix it.  Also, refactored generic GPIO to be
  simpler.

  Some of that is still waiting to trickle down from the subsystems all
  over the kernel that provide random gpio_chips, I've touched every
  single GPIO driver in the kernel now, oh man I didn't know I was
  responsible for so much...

  Apart from that we're churning along as usual.

  I took some effort to test and retest so it should merge nicely and we
  shook out a couple of bugs in -next.

  Infrastructural changes:

   - In struct gpio_chip, rename the .dev node to .parent to better
     reflect the fact that this is not the GPIO struct device
     abstraction.  We will add that soon so this would be totallt
     confusing.

   - It was noted that the driver .get_value() callbacks was sometimes
     reporting negative -ERR values to the gpiolib core, expecting them
     to be propagated to consumer gpiod_get_value() and gpio_get_value()
     calls.  This was not happening, so as there was a mess of drivers
     returning negative errors and some returning "anything else than
     zero" to indicate that a line was active.  As some would have bit
     31 set to indicate "line active" it clashed with negative error
     codes.  This is fixed by the largeish series clamping values in all
     drivers with !!value to [0,1] and then augmenting the code to
     propagate error codes to consumers.  (Includes some ACKed patches
     in other subsystems.)

   - Add a void *data pointer to struct gpio_chip.  The container_of()
     design pattern is indeed very nice, but we want to reform the
     struct gpio_chip to be a non-volative, stateless business, and keep
     states internal to the gpiolib to be able to hold on to the state
     when adding a proper userspace ABI (character device) further down
     the road.  To achieve this, drivers need a handle at the internal
     state that is not dependent on their struct gpio_chip() so we add
     gpiochip_add_data() and gpiochip_get_data() following the pattern
     of many other subsystems.  All the "use gpiochip data pointer"
     patches transforms drivers to this scheme.

   - The Generic GPIO chip header has been merged into the general
     <linux/gpio/driver.h> header, and the custom header for that
     removed.  Instead of having a separate mm_gpio_chip struct for
     these generic drivers, merge that into struct gpio_chip,
     simplifying the code and removing the need for separate and
     confusing includes.

  Misc improvements:

   - Stabilize the way GPIOs are looked up from the ACPI legacy
     specification.

   - Incremental driver features for PXA, PCA953X, Lantiq (patches from
     the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48

  New drivers:

   - Add a GPIO chip to the ALSA SoC AC97 driver.

   - Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir,
     but the branch is merged here too to account for infrastructural
     changes).

   - The sx150x driver now supports the sx1502"

* tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits)
  gpio: generic: make bgpio_pdata always visible
  gpiolib: fix chip order in gpio list
  gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()
  gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs()
  gpio: brcmstb: Allow building driver for BMIPS_GENERIC
  gpio: brcmstb: Set endian flags for big-endian MIPS
  gpio: moxart: fix build regression
  gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs()
  leds: pca9532: use gpiochip data pointer
  leds: tca6507: use gpiochip data pointer
  hid: cp2112: use gpiochip data pointer
  bcma: gpio: use gpiochip data pointer
  avr32: gpio: use gpiochip data pointer
  video: fbdev: via: use gpiochip data pointer
  gpio: pch: Optimize pch_gpio_get()
  Revert "pinctrl: lantiq: Implement gpio_chip.to_irq"
  pinctrl: nsp-gpio: use gpiochip data pointer
  pinctrl: vt8500-wmt: use gpiochip data pointer
  pinctrl: exynos5440: use gpiochip data pointer
  pinctrl: at91-pio4: use gpiochip data pointer
  ...
2016-01-17 12:32:01 -08:00

1228 lines
31 KiB
C

/*
* 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:
* http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf
*/
#include <linux/gpio/driver.h>
#include <linux/hid.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/nls.h>
#include <linux/usb/ch9.h>
#include "hid-ids.h"
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;
};
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[5];
int ret;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
sizeof(buf), HID_FEATURE_REPORT,
HID_REQ_GET_REPORT);
if (ret != sizeof(buf)) {
hid_err(hdev, "error requesting GPIO config: %d\n", ret);
return ret;
}
buf[1] &= ~(1 << offset);
buf[2] = gpio_push_pull;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
if (ret < 0) {
hid_err(hdev, "error setting GPIO config: %d\n", ret);
return ret;
}
return 0;
}
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[3];
int ret;
buf[0] = CP2112_GPIO_SET;
buf[1] = value ? 0xff : 0;
buf[2] = 1 << offset;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
if (ret < 0)
hid_err(hdev, "error setting GPIO values: %d\n", ret);
}
static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 buf[2];
int ret;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf),
HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
if (ret != sizeof(buf)) {
hid_err(hdev, "error requesting GPIO values: %d\n", ret);
return ret;
}
return (buf[1] >> 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[5];
int ret;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
sizeof(buf), HID_FEATURE_REPORT,
HID_REQ_GET_REPORT);
if (ret != sizeof(buf)) {
hid_err(hdev, "error requesting GPIO config: %d\n", ret);
return ret;
}
buf[1] |= 1 << offset;
buf[2] = gpio_push_pull;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
if (ret < 0) {
hid_err(hdev, "error setting GPIO config: %d\n", ret);
return ret;
}
/*
* 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;
}
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:
size = I2C_SMBUS_BLOCK_DATA;
/* fallthrough */
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_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 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;
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;
}
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
ret = -ENOMEM;
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 hiddev%d", hdev->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_free_dev;
}
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);
return ret;
err_gpiochip_remove:
gpiochip_remove(&dev->gc);
err_free_i2c:
i2c_del_adapter(&dev->adap);
err_free_dev:
kfree(dev);
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);
sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
gpiochip_remove(&dev->gc);
i2c_del_adapter(&dev->adap);
/* 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);
kfree(dev);
}
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");