2019-06-03 03:50:23

by Pi-Hsun Shih

Subject: [PATCH v10 6/7] mfd: cros_ec: differentiate SCP from EC by feature bit.

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 <[email protected]>
Acked-by: Enric Balletbo i Serra <[email protected]>
---
Changes from v9:
- Remove changes in cros_ec_commands.h (which is sync in
https://lore.kernel.org/lkml/20190518063949.GY4319@dell/T/).

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 +
2 files changed, 11 insertions(+)

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
--
2.22.0.rc1.257.g3120a18244-goog

2019-06-12 08:58:28

by Lee Jones

Subject: Re: [PATCH v10 6/7] mfd: cros_ec: differentiate SCP from EC by feature bit.

On Mon, 03 Jun 2019, Pi-Hsun Shih wrote:

> 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 <[email protected]>
> Acked-by: Enric Balletbo i Serra <[email protected]>
> ---
> Changes from v9:
> - Remove changes in cros_ec_commands.h (which is sync in
> https://lore.kernel.org/lkml/20190518063949.GY4319@dell/T/).
>
> 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 +
> 2 files changed, 11 insertions(+)

Applied, thanks.

--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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