Commit Graph

5 Commits

Author SHA1 Message Date
Harshit Mogalapalli 62ac247355 HID: mcp2221: prevent a buffer overflow in mcp_smbus_write()
Smatch Warning:
drivers/hid/hid-mcp2221.c:388 mcp_smbus_write() error: __memcpy()
'&mcp->txbuf[5]' too small (59 vs 255)
drivers/hid/hid-mcp2221.c:388 mcp_smbus_write() error: __memcpy() 'buf'
too small (34 vs 255)

The 'len' variable can take a value between 0-255 as it can come from
data->block[0] and it is user data. So add an bound check to prevent a
buffer overflow in memcpy().

Fixes: 67a95c2146 ("HID: mcp2221: add usb to i2c-smbus host bridge")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2022-07-21 11:54:40 +02:00
Lars Povlsen 567b8e9fed HID: mcp2221: Fix GPIO output handling
The mcp2221 driver GPIO output handling has has several issues.

* A wrong value is used for the GPIO direction.

* Wrong offsets are calculated for some GPIO set value/set direction
  operations, when offset is larger than 0.

This has been fixed by introducing proper manifest constants for the
direction encoding, and using 'offsetof' when calculating GPIO
register offsets.

The updated driver has been tested with the Sparx5 pcb134/pcb135
board, which has the mcp2221 device with several (output) GPIO's.

Fixes: 328de1c519 ("HID: mcp2221: add GPIO functionality support")
Reviewed-by: Rishi Gupta <gupt21@gmail.com>
Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2020-11-05 11:16:53 +01:00
Alexander A. Klimov b266eacf5f HID: mcp2221: Replace HTTP links with HTTPS ones
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2020-07-20 12:24:01 +02:00
Rishi Gupta 328de1c519 HID: mcp2221: add GPIO functionality support
MCP2221 has 4 pins that can be used as GPIO or configured
for alternate functionality such as clock generation and
IRQ detection. This patch adds support for GPIO functionality.

To set direction of a pin or to toggle its state after it
has been configured as GPIO, driver sends command to mcp2221
and parses response received from mcp2221. Based on this
response either 0 or appropriate error code is returned to
GPIO framework.

To get the direction or current state of a pin, driver
sends command and read response from the device. Based on
the response received from device direction or value
is sent to the GPIO framework.

Command from driver to mcp2221 device are output report.
Response received from mcp2221 is input report.

Datasheet (page 45-48) contains details about how to decode
the response received from device:
http://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf

Signed-off-by: Rishi Gupta <gupt21@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2020-04-16 22:15:31 +02:00
Rishi Gupta 67a95c2146 HID: mcp2221: add usb to i2c-smbus host bridge
MCP2221 is a USB HID to I2C/SMbus host bridge device. This
commit implements i2c and smbus host adapter support. 7-bit
address and i2c multi-message transaction is also supported.

Signed-off-by: Rishi Gupta <gupt21@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2020-03-10 12:37:42 +01:00