[PATCH v4 01/17] mfd: cros_ec: Add sensor_count and make check_features public

Gwendal Grignou
2019-11-05T22:27:04Z

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>
---
Changes in v4:
Check patch with --strict option
Use sizeof(*obj) instead of sizeof(struct ...obj)
Alignement
Remove useless ().
Changes in v3:
Fix doxygen comments.
Changes in v2:
Fix spelling in commit message.
Cleanup the case where DUMP command is not supported.
Move code from mfd to platform/chrome/

drivers/mfd/cros_ec_dev.c | 32 ------
drivers/platform/chrome/cros_ec_proto.c | 117 ++++++++++++++++++++
include/linux/platform_data/cros_ec_proto.h | 5 +
3 files changed, 122 insertions(+), 32 deletions(-)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 6e6dfd6c1871..a35104e35cb4 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -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));
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 7db58771ec77..b502933e911b 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -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);
diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
index 0d4e4aaed37a..f3de0662135d 100644
--- a/include/linux/platform_data/cros_ec_proto.h
+++ b/include/linux/platform_data/cros_ec_proto.h
@@ -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 */
--
2.24.0.rc1.363.gb1bccd3e3d-goog