linux/drivers/extcon/extcon-usbc-cros-ec.c
Christophe JAILLET 1cf76c4eeb extcon: cros-ec: Fix a potential NULL pointer dereference
Return -ENOMEM in case of memory allocation failure. This avoids a NULL
pointer dereference.

Fixes: c698316661 ("extcon: cros-ec: Add extcon-cros-ec driver to support display out")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2017-08-07 15:34:20 +09:00

418 lines
10 KiB
C

/**
* drivers/extcon/extcon-usbc-cros-ec - ChromeOS Embedded Controller extcon
*
* Copyright (C) 2017 Google, Inc
* Author: Benson Leung <bleung@chromium.org>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that 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.
*/
#include <linux/extcon.h>
#include <linux/kernel.h>
#include <linux/mfd/cros_ec.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/sched.h>
struct cros_ec_extcon_info {
struct device *dev;
struct extcon_dev *edev;
int port_id;
struct cros_ec_device *ec;
struct notifier_block notifier;
bool dp; /* DisplayPort enabled */
bool mux; /* SuperSpeed (usb3) enabled */
unsigned int power_type;
};
static const unsigned int usb_type_c_cable[] = {
EXTCON_DISP_DP,
EXTCON_NONE,
};
/**
* cros_ec_pd_command() - Send a command to the EC.
* @info: pointer to struct cros_ec_extcon_info
* @command: EC command
* @version: EC command version
* @outdata: EC command output data
* @outsize: Size of outdata
* @indata: EC command input data
* @insize: Size of indata
*
* Return: 0 on success, <0 on failure.
*/
static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
unsigned int command,
unsigned int version,
void *outdata,
unsigned int outsize,
void *indata,
unsigned int insize)
{
struct cros_ec_command *msg;
int ret;
msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
if (!msg)
return -ENOMEM;
msg->version = version;
msg->command = command;
msg->outsize = outsize;
msg->insize = insize;
if (outsize)
memcpy(msg->data, outdata, outsize);
ret = cros_ec_cmd_xfer_status(info->ec, msg);
if (ret >= 0 && insize)
memcpy(indata, msg->data, insize);
kfree(msg);
return ret;
}
/**
* cros_ec_usb_get_power_type() - Get power type info about PD device attached
* to given port.
* @info: pointer to struct cros_ec_extcon_info
*
* Return: power type on success, <0 on failure.
*/
static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
{
struct ec_params_usb_pd_power_info req;
struct ec_response_usb_pd_power_info resp;
int ret;
req.port = info->port_id;
ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
&req, sizeof(req), &resp, sizeof(resp));
if (ret < 0)
return ret;
return resp.type;
}
/**
* cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
* @info: pointer to struct cros_ec_extcon_info
*
* Return: PD mux state on success, <0 on failure.
*/
static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
{
struct ec_params_usb_pd_mux_info req;
struct ec_response_usb_pd_mux_info resp;
int ret;
req.port = info->port_id;
ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
&req, sizeof(req),
&resp, sizeof(resp));
if (ret < 0)
return ret;
return resp.flags;
}
/**
* cros_ec_usb_get_role() - Get role info about possible PD device attached to a
* given port.
* @info: pointer to struct cros_ec_extcon_info
* @polarity: pointer to cable polarity (return value)
*
* Return: role info on success, -ENOTCONN if no cable is connected, <0 on
* failure.
*/
static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
bool *polarity)
{
struct ec_params_usb_pd_control pd_control;
struct ec_response_usb_pd_control_v1 resp;
int ret;
pd_control.port = info->port_id;
pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
&pd_control, sizeof(pd_control),
&resp, sizeof(resp));
if (ret < 0)
return ret;
if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
return -ENOTCONN;
*polarity = resp.polarity;
return resp.role;
}
/**
* cros_ec_pd_get_num_ports() - Get number of EC charge ports.
* @info: pointer to struct cros_ec_extcon_info
*
* Return: number of ports on success, <0 on failure.
*/
static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
{
struct ec_response_usb_pd_ports resp;
int ret;
ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
0, NULL, 0, &resp, sizeof(resp));
if (ret < 0)
return ret;
return resp.num_ports;
}
static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
bool force)
{
struct device *dev = info->dev;
int role, power_type;
bool polarity = false;
bool dp = false;
bool mux = false;
bool hpd = false;
power_type = cros_ec_usb_get_power_type(info);
if (power_type < 0) {
dev_err(dev, "failed getting power type err = %d\n",
power_type);
return power_type;
}
role = cros_ec_usb_get_role(info, &polarity);
if (role < 0) {
if (role != -ENOTCONN) {
dev_err(dev, "failed getting role err = %d\n", role);
return role;
}
} else {
int pd_mux_state;
pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
if (pd_mux_state < 0)
pd_mux_state = USB_PD_MUX_USB_ENABLED;
dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
}
if (force || info->dp != dp || info->mux != mux ||
info->power_type != power_type) {
info->dp = dp;
info->mux = mux;
info->power_type = power_type;
extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
extcon_set_property(info->edev, EXTCON_DISP_DP,
EXTCON_PROP_USB_TYPEC_POLARITY,
(union extcon_property_value)(int)polarity);
extcon_set_property(info->edev, EXTCON_DISP_DP,
EXTCON_PROP_USB_SS,
(union extcon_property_value)(int)mux);
extcon_set_property(info->edev, EXTCON_DISP_DP,
EXTCON_PROP_DISP_HPD,
(union extcon_property_value)(int)hpd);
extcon_sync(info->edev, EXTCON_DISP_DP);
} else if (hpd) {
extcon_set_property(info->edev, EXTCON_DISP_DP,
EXTCON_PROP_DISP_HPD,
(union extcon_property_value)(int)hpd);
extcon_sync(info->edev, EXTCON_DISP_DP);
}
return 0;
}
static int extcon_cros_ec_event(struct notifier_block *nb,
unsigned long queued_during_suspend,
void *_notify)
{
struct cros_ec_extcon_info *info;
struct cros_ec_device *ec;
u32 host_event;
info = container_of(nb, struct cros_ec_extcon_info, notifier);
ec = info->ec;
host_event = cros_ec_get_host_event(ec);
if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
extcon_cros_ec_detect_cable(info, false);
return NOTIFY_OK;
}
return NOTIFY_DONE;
}
static int extcon_cros_ec_probe(struct platform_device *pdev)
{
struct cros_ec_extcon_info *info;
struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
int numports, ret;
info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->dev = dev;
info->ec = ec;
if (np) {
u32 port;
ret = of_property_read_u32(np, "google,usb-port-id", &port);
if (ret < 0) {
dev_err(dev, "Missing google,usb-port-id property\n");
return ret;
}
info->port_id = port;
} else {
info->port_id = pdev->id;
}
numports = cros_ec_pd_get_num_ports(info);
if (numports < 0) {
dev_err(dev, "failed getting number of ports! ret = %d\n",
numports);
return numports;
}
if (info->port_id >= numports) {
dev_err(dev, "This system only supports %d ports\n", numports);
return -ENODEV;
}
info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
if (IS_ERR(info->edev)) {
dev_err(dev, "failed to allocate extcon device\n");
return -ENOMEM;
}
ret = devm_extcon_dev_register(dev, info->edev);
if (ret < 0) {
dev_err(dev, "failed to register extcon device\n");
return ret;
}
extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
EXTCON_PROP_USB_TYPEC_POLARITY);
extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
EXTCON_PROP_USB_SS);
extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
EXTCON_PROP_DISP_HPD);
platform_set_drvdata(pdev, info);
/* Get PD events from the EC */
info->notifier.notifier_call = extcon_cros_ec_event;
ret = blocking_notifier_chain_register(&info->ec->event_notifier,
&info->notifier);
if (ret < 0) {
dev_err(dev, "failed to register notifier\n");
return ret;
}
/* Perform initial detection */
ret = extcon_cros_ec_detect_cable(info, true);
if (ret < 0) {
dev_err(dev, "failed to detect initial cable state\n");
goto unregister_notifier;
}
return 0;
unregister_notifier:
blocking_notifier_chain_unregister(&info->ec->event_notifier,
&info->notifier);
return ret;
}
static int extcon_cros_ec_remove(struct platform_device *pdev)
{
struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
blocking_notifier_chain_unregister(&info->ec->event_notifier,
&info->notifier);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int extcon_cros_ec_suspend(struct device *dev)
{
return 0;
}
static int extcon_cros_ec_resume(struct device *dev)
{
int ret;
struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
ret = extcon_cros_ec_detect_cable(info, true);
if (ret < 0)
dev_err(dev, "failed to detect cable state on resume\n");
return 0;
}
static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
};
#define DEV_PM_OPS (&extcon_cros_ec_dev_pm_ops)
#else
#define DEV_PM_OPS NULL
#endif /* CONFIG_PM_SLEEP */
#ifdef CONFIG_OF
static const struct of_device_id extcon_cros_ec_of_match[] = {
{ .compatible = "google,extcon-usbc-cros-ec" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
#endif /* CONFIG_OF */
static struct platform_driver extcon_cros_ec_driver = {
.driver = {
.name = "extcon-usbc-cros-ec",
.of_match_table = of_match_ptr(extcon_cros_ec_of_match),
.pm = DEV_PM_OPS,
},
.remove = extcon_cros_ec_remove,
.probe = extcon_cros_ec_probe,
};
module_platform_driver(extcon_cros_ec_driver);
MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
MODULE_LICENSE("GPL");