[PATCH 2/3] mfd: cros_ec_dev: Only register PCHG device if present

[Stephen Boyd]

Don't create a device for the peripheral charger (PCHG) if there aren't
any peripheral charger ports. This removes a device on most ChromeOS
systems, because the peripheral charger functionality isn't always
present.

Cc: Lee Jones <lee.jones@xxxxxxxxxx>
Cc: Daisuke Nojiri <dnojiri@xxxxxxxxxxxx>
Cc: Benson Leung <bleung@xxxxxxxxxxxx>
Cc: Guenter Roeck <groeck@xxxxxxxxxxxx>
Cc: <chrome-platform@xxxxxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
---
 drivers/mfd/cros_ec_dev.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 546feef851ab..d2ba6a1fbc1d 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -114,6 +114,9 @@ static const struct mfd_cell cros_ec_platform_cells[] = {
 	{ .name = "cros-ec-chardev", },
 	{ .name = "cros-ec-debugfs", },
 	{ .name = "cros-ec-sysfs", },
+};
+
+static const struct mfd_cell cros_ec_pchg_cells[] = {
 	{ .name = "cros-ec-pchg", },
 };
 
@@ -242,6 +245,19 @@ static int ec_device_probe(struct platform_device *pdev)
 		}
 	}
 
+	/*
+	 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
+	 * it can be detected by querying the number of peripheral chargers.
+	 */
+	if (cros_ec_pchg_port_count(ec)) {
+		retval = mfd_add_hotplug_devices(ec->dev,
+					cros_ec_pchg_cells,
+					ARRAY_SIZE(cros_ec_pchg_cells));
+		if (retval)
+			dev_warn(ec->dev, "failed to add pchg: %d\n",
+				 retval);
+	}
+
 	/*
 	 * The following subdevices cannot be detected by sending the
 	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
-- 
https://chromeos.dev