From a16b2e28190255a0729c27902fa88fb8fff39bb0 Mon Sep 17 00:00:00 2001 From: Gwendal Grignou Date: Tue, 19 Nov 2019 13:45:45 +0100 Subject: 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 Acked-by: Lee Jones Signed-off-by: Enric Balletbo i Serra --- drivers/platform/chrome/cros_ec_proto.c | 117 ++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) (limited to 'drivers/platform') diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index 7db58771ec77..12bdd1f3aee9 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); -- cgit