mfd / platform: cros_ec: Add sensor_count and make check_features public

Add a new function to return the number of MEMS sensors available in a
ChromeOS Embedded Controller. It uses MOTIONSENSE_CMD_DUMP if available
or a specific memory map ACPI registers to find out.

Also, make check_features public as it can be useful for other drivers
to know what the Embedded Controller supports.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
This commit is contained in:
Gwendal Grignou 2019-11-19 13:45:45 +01:00 committed by Enric Balletbo i Serra
parent c9b465683a
commit a16b2e2819
3 changed files with 122 additions and 32 deletions

View File

@ -112,38 +112,6 @@ static const struct mfd_cell cros_ec_vbc_cells[] = {
{ .name = "cros-ec-vbc", }
};
static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
{
struct cros_ec_command *msg;
int ret;
if (ec->features[0] == -1U && ec->features[1] == -1U) {
/* features bitmap not read yet */
msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
if (!msg)
return -ENOMEM;
msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
msg->insize = sizeof(ec->features);
ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
if (ret < 0) {
dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
ret, msg->result);
memset(ec->features, 0, sizeof(ec->features));
} else {
memcpy(ec->features, msg->data, sizeof(ec->features));
}
dev_dbg(ec->dev, "EC features %08x %08x\n",
ec->features[0], ec->features[1]);
kfree(msg);
}
return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
}
static void cros_ec_class_release(struct device *dev)
{
kfree(to_cros_ec_dev(dev));

View File

@ -717,3 +717,120 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
return host_event;
}
EXPORT_SYMBOL(cros_ec_get_host_event);
/**
* cros_ec_check_features() - Test for the presence of EC features
*
* @ec: EC device, does not have to be connected directly to the AP,
* can be daisy chained through another device.
* @feature: One of ec_feature_code bit.
*
* Call this function to test whether the ChromeOS EC supports a feature.
*
* Return: 1 if supported, 0 if not
*/
int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
{
struct cros_ec_command *msg;
int ret;
if (ec->features[0] == -1U && ec->features[1] == -1U) {
/* features bitmap not read yet */
msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
if (!msg)
return -ENOMEM;
msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
msg->insize = sizeof(ec->features);
ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
if (ret < 0) {
dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
ret, msg->result);
memset(ec->features, 0, sizeof(ec->features));
} else {
memcpy(ec->features, msg->data, sizeof(ec->features));
}
dev_dbg(ec->dev, "EC features %08x %08x\n",
ec->features[0], ec->features[1]);
kfree(msg);
}
return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
}
EXPORT_SYMBOL_GPL(cros_ec_check_features);
/**
* cros_ec_get_sensor_count() - Return the number of MEMS sensors supported.
*
* @ec: EC device, does not have to be connected directly to the AP,
* can be daisy chained through another device.
* Return: < 0 in case of error.
*/
int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
{
/*
* Issue a command to get the number of sensor reported.
* If not supported, check for legacy mode.
*/
int ret, sensor_count;
struct ec_params_motion_sense *params;
struct ec_response_motion_sense *resp;
struct cros_ec_command *msg;
struct cros_ec_device *ec_dev = ec->ec_dev;
u8 status;
msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
GFP_KERNEL);
if (!msg)
return -ENOMEM;
msg->version = 1;
msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
msg->outsize = sizeof(*params);
msg->insize = sizeof(*resp);
params = (struct ec_params_motion_sense *)msg->data;
params->cmd = MOTIONSENSE_CMD_DUMP;
ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
if (ret < 0) {
sensor_count = ret;
} else if (msg->result != EC_RES_SUCCESS) {
sensor_count = -EPROTO;
} else {
resp = (struct ec_response_motion_sense *)msg->data;
sensor_count = resp->dump.sensor_count;
}
kfree(msg);
/*
* Check legacy mode: Let's find out if sensors are accessible
* via LPC interface.
*/
if (sensor_count == -EPROTO &&
ec->cmd_offset == 0 &&
ec_dev->cmd_readmem) {
ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS,
1, &status);
if (ret >= 0 &&
(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
/*
* We have 2 sensors, one in the lid, one in the base.
*/
sensor_count = 2;
} else {
/*
* EC uses LPC interface and no sensors are presented.
*/
sensor_count = 0;
}
} else if (sensor_count == -EPROTO) {
/* EC responded, but does not understand DUMP command. */
sensor_count = 0;
}
return sensor_count;
}
EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);

View File

@ -12,6 +12,7 @@
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/mfd/cros_ec.h>
#include <linux/platform_data/cros_ec_commands.h>
#define CROS_EC_DEV_NAME "cros_ec"
@ -213,4 +214,8 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
int cros_ec_check_features(struct cros_ec_dev *ec, int feature);
int cros_ec_get_sensor_count(struct cros_ec_dev *ec);
#endif /* __LINUX_CROS_EC_PROTO_H */