System Companion Processor (SCP) is Cortex M4 co-processor on some MediaTek platform that can run EC-style firmware. Since a SCP and EC would both exist on a system, and use the cros_ec_dev driver, we need to differentiate between them for the userspace, or they would both be registered at /dev/cros_ec, causing a conflict.
Signed-off-by: Pi-Hsun Shih <pih...@chromium.org> --- Changes from v8: - No change. Changes from v7: - Address comments in v7. - Rebase the series onto https://lore.kernel.org/patchwork/patch/1059196/. Changes from v6, v5, v4, v3, v2: - No change. Changes from v1: - New patch extracted from Patch 5. --- drivers/mfd/cros_ec_dev.c | 10 ++++++++++ include/linux/mfd/cros_ec.h | 1 + include/linux/mfd/cros_ec_commands.h | 2 +- 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c index a5391f96eafd..66107de3dbce 100644 --- a/drivers/mfd/cros_ec_dev.c +++ b/drivers/mfd/cros_ec_dev.c @@ -440,6 +440,16 @@ static int ec_device_probe(struct platform_device *pdev) ec_platform->ec_name = CROS_EC_DEV_TP_NAME; } + /* Check whether this is actually a SCP rather than an EC. */ + if (cros_ec_check_features(ec, EC_FEATURE_SCP)) { + dev_info(dev, "CrOS SCP MCU detected.\n"); + /* + * Help userspace differentiating ECs from SCP, + * regardless of the probing order. + */ + ec_platform->ec_name = CROS_EC_DEV_SCP_NAME; + } + /* * Add the class device * Link to the character device for creating the /dev entry diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h index cfa78bb4990f..751cb3756d49 100644 --- a/include/linux/mfd/cros_ec.h +++ b/include/linux/mfd/cros_ec.h @@ -27,6 +27,7 @@ #define CROS_EC_DEV_PD_NAME "cros_pd" #define CROS_EC_DEV_TP_NAME "cros_tp" #define CROS_EC_DEV_ISH_NAME "cros_ish" +#define CROS_EC_DEV_SCP_NAME "cros_scp" /* * The EC is unresponsive for a time after a reboot command. Add a diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h index dcec96f01879..8b578b4c1ec7 100644 --- a/include/linux/mfd/cros_ec_commands.h +++ b/include/linux/mfd/cros_ec_commands.h @@ -884,7 +884,7 @@ enum ec_feature_code { EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS = 37, /* EC supports audio codec. */ EC_FEATURE_AUDIO_CODEC = 38, - /* EC Supports SCP. */ + /* The MCU is a System Companion Processor (SCP). */ EC_FEATURE_SCP = 39, /* The MCU is an Integrated Sensor Hub */ EC_FEATURE_ISH = 40, -- 2.22.0.rc1.257.g3120a18244-goog
