linux/drivers/regulator/cros-ec-regulator.c
Axel Lin ce41090057
regulator: cros-ec-regulator: Add NULL test for devm_kmemdup call
Fix possible NULL pointer dereference.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20200802032509.305425-1-axel.lin@ingics.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-08-04 13:24:37 +01:00

256 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright 2020 Google LLC.
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/slab.h>
struct cros_ec_regulator_data {
struct regulator_desc desc;
struct regulator_dev *dev;
struct cros_ec_device *ec_dev;
u32 index;
u16 *voltages_mV;
u16 num_voltages;
};
static int cros_ec_cmd(struct cros_ec_device *ec, u32 version, u32 command,
void *outdata, u32 outsize, void *indata, u32 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 (outdata && outsize > 0)
memcpy(msg->data, outdata, outsize);
ret = cros_ec_cmd_xfer_status(ec, msg);
if (ret < 0)
goto cleanup;
if (insize)
memcpy(indata, msg->data, insize);
cleanup:
kfree(msg);
return ret;
}
static int cros_ec_regulator_enable(struct regulator_dev *dev)
{
struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
struct ec_params_regulator_enable cmd = {
.index = data->index,
.enable = 1,
};
return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
sizeof(cmd), NULL, 0);
}
static int cros_ec_regulator_disable(struct regulator_dev *dev)
{
struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
struct ec_params_regulator_enable cmd = {
.index = data->index,
.enable = 0,
};
return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
sizeof(cmd), NULL, 0);
}
static int cros_ec_regulator_is_enabled(struct regulator_dev *dev)
{
struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
struct ec_params_regulator_is_enabled cmd = {
.index = data->index,
};
struct ec_response_regulator_is_enabled resp;
int ret;
ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_IS_ENABLED, &cmd,
sizeof(cmd), &resp, sizeof(resp));
if (ret < 0)
return ret;
return resp.enabled;
}
static int cros_ec_regulator_list_voltage(struct regulator_dev *dev,
unsigned int selector)
{
struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
if (selector >= data->num_voltages)
return -EINVAL;
return data->voltages_mV[selector] * 1000;
}
static int cros_ec_regulator_get_voltage(struct regulator_dev *dev)
{
struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
struct ec_params_regulator_get_voltage cmd = {
.index = data->index,
};
struct ec_response_regulator_get_voltage resp;
int ret;
ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_VOLTAGE, &cmd,
sizeof(cmd), &resp, sizeof(resp));
if (ret < 0)
return ret;
return resp.voltage_mv * 1000;
}
static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV,
int max_uV, unsigned int *selector)
{
struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
int min_mV = DIV_ROUND_UP(min_uV, 1000);
int max_mV = max_uV / 1000;
struct ec_params_regulator_set_voltage cmd = {
.index = data->index,
.min_mv = min_mV,
.max_mv = max_mV,
};
/*
* This can happen when the given range [min_uV, max_uV] doesn't
* contain any voltage that can be represented exactly in mV.
*/
if (min_mV > max_mV)
return -EINVAL;
return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_SET_VOLTAGE, &cmd,
sizeof(cmd), NULL, 0);
}
static const struct regulator_ops cros_ec_regulator_voltage_ops = {
.enable = cros_ec_regulator_enable,
.disable = cros_ec_regulator_disable,
.is_enabled = cros_ec_regulator_is_enabled,
.list_voltage = cros_ec_regulator_list_voltage,
.get_voltage = cros_ec_regulator_get_voltage,
.set_voltage = cros_ec_regulator_set_voltage,
};
static int cros_ec_regulator_init_info(struct device *dev,
struct cros_ec_regulator_data *data)
{
struct ec_params_regulator_get_info cmd = {
.index = data->index,
};
struct ec_response_regulator_get_info resp;
int ret;
ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_INFO, &cmd,
sizeof(cmd), &resp, sizeof(resp));
if (ret < 0)
return ret;
data->num_voltages =
min_t(u16, ARRAY_SIZE(resp.voltages_mv), resp.num_voltages);
data->voltages_mV =
devm_kmemdup(dev, resp.voltages_mv,
sizeof(u16) * data->num_voltages, GFP_KERNEL);
if (!data->voltages_mV)
return -ENOMEM;
data->desc.n_voltages = data->num_voltages;
/* Make sure the returned name is always a valid string */
resp.name[ARRAY_SIZE(resp.name) - 1] = '\0';
data->desc.name = devm_kstrdup(dev, resp.name, GFP_KERNEL);
if (!data->desc.name)
return -ENOMEM;
return 0;
}
static int cros_ec_regulator_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct cros_ec_regulator_data *drvdata;
struct regulator_init_data *init_data;
struct regulator_config cfg = {};
struct regulator_desc *desc;
int ret;
drvdata = devm_kzalloc(
&pdev->dev, sizeof(struct cros_ec_regulator_data), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
drvdata->ec_dev = dev_get_drvdata(dev->parent);
desc = &drvdata->desc;
init_data = of_get_regulator_init_data(dev, np, desc);
if (!init_data)
return -EINVAL;
ret = of_property_read_u32(np, "reg", &drvdata->index);
if (ret < 0)
return ret;
desc->owner = THIS_MODULE;
desc->type = REGULATOR_VOLTAGE;
desc->ops = &cros_ec_regulator_voltage_ops;
ret = cros_ec_regulator_init_info(dev, drvdata);
if (ret < 0)
return ret;
cfg.dev = &pdev->dev;
cfg.init_data = init_data;
cfg.driver_data = drvdata;
cfg.of_node = np;
drvdata->dev = devm_regulator_register(dev, &drvdata->desc, &cfg);
if (IS_ERR(drvdata->dev)) {
dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
return PTR_ERR(drvdata->dev);
}
platform_set_drvdata(pdev, drvdata);
return 0;
}
static const struct of_device_id regulator_cros_ec_of_match[] = {
{ .compatible = "google,cros-ec-regulator", },
{}
};
MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match);
static struct platform_driver cros_ec_regulator_driver = {
.probe = cros_ec_regulator_probe,
.driver = {
.name = "cros-ec-regulator",
.of_match_table = regulator_cros_ec_of_match,
},
};
module_platform_driver(cros_ec_regulator_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ChromeOS EC controlled regulator");
MODULE_AUTHOR("Pi-Hsun Shih <pihsun@chromium.org>");