Hi Matthias,

I am also interested on the answer of Brian comments :). One small comment.

Missatge de Brian Norris [off-list ref] del dia dt., 19 de
juny 2018 a les 1:22:

Hi,

On Thu, Jun 14, 2018 at 12:47:12PM -0700, Matthias Kaehlcke wrote:

quoted

Instantiate the CrOS EC throttler if it is enabled in the kernel
configuration.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
Changes in v3:
- patch added to series

 drivers/mfd/cros_ec.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index 36156a41499c..5f52b6e2c21a 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c

@@ -91,6 +91,10 @@ static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
      return cros_ec_cmd_xfer(ec_dev, &buf.msg);
 }

+static const struct mfd_cell ec_throttler_cell = {
+     { .name = "cros-ec-throttler" }
+};
+

As Brian said I think that this should go in cros_ec_dev?

Even when only there is one cell we tend to use the array format (see
i.e the cros-ec-rtc and the others in cros_ec_dev).

+static const struct mfd_cell ec_throttler_cells[] = {
+     { .name = "cros-ec-throttler" }
+};

quoted

 int cros_ec_register(struct cros_ec_device *ec_dev)
 {
      struct device *dev = ec_dev->dev;

@@ -153,6 +157,18 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
              }
      }

+     if (IS_ENABLED(CONFIG_CROS_EC_THROTTLER)) {
+             err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
+                                   &ec_throttler_cell, 1, NULL, ec_dev->irq,

ARRAY_SIZE(ec_throttler_cells)

quoted

+                                   NULL);

Most of this similar sub-device registration seems to have moved to
cros_ec_dev.c, in ec_device_probe(). Should this do the same?

And on a similar note: is there a way to determine EC support for this
feature (e.g., EC_FEATURE_*)? Or do we just have to listen for
appropriate throttling events that may never come?

Also, is this very useful on non-DT systems? Does this fail gracefully?

Brian

quoted

+             if (err) {
+                     dev_err(dev,
+                             "Failed to register throttler subdevice %d\n",
+                             err);
+                     return err;
+             }
+     }
+
      if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
              err = devm_of_platform_populate(dev);
              if (err) {
--
2.18.0.rc1.242.g61856ae69a-goog

Cheers,
 Enric