Input: cros_ec_keyb - handle x86 detachable/convertible Chromebooks

Some detachable/convertible x86 Chromebooks use EC buttons/switches
interface to signal volume up/down and other buttons. This configuration is
signalled via presence of GOOG0007 ACPI device. The main keyboard on such
Chromebooks is still using the standard 8042/atkbd combo.

Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220526231230.2805147-2-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
index e8338b1..c14136b 100644 (file)
--- a/drivers/input/keyboard/cros_ec_keyb.c
+++ b/drivers/input/keyboard/cros_ec_keyb.c
@@ -12,6 +12,7 @@
 // expensive.
 
 #include <linux/module.h>
+#include <linux/acpi.h>
 #include <linux/bitops.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
@@ -677,14 +678,19 @@ static const struct attribute_group cros_ec_keyb_attr_group = {
 
 static int cros_ec_keyb_probe(struct platform_device *pdev)
 {
-       struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
+       struct cros_ec_device *ec;
        struct device *dev = &pdev->dev;
        struct cros_ec_keyb *ckdev;
        bool buttons_switches_only = device_get_match_data(dev);
        int err;
 
-       if (!dev->of_node)
-               return -ENODEV;
+       /*
+        * If the parent ec device has not been probed yet, defer the probe of
+        * this keyboard/button driver until later.
+        */
+       ec = dev_get_drvdata(pdev->dev.parent);
+       if (!ec)
+               return -EPROBE_DEFER;
 
        ckdev = devm_kzalloc(dev, sizeof(*ckdev), GFP_KERNEL);
        if (!ckdev)
@@ -737,6 +743,14 @@ static int cros_ec_keyb_remove(struct platform_device *pdev)
        return 0;
 }
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id cros_ec_keyb_acpi_match[] = {
+       { "GOOG0007", true },
+       { }
+};
+MODULE_DEVICE_TABLE(acpi, cros_ec_keyb_acpi_match);
+#endif
+
 #ifdef CONFIG_OF
 static const struct of_device_id cros_ec_keyb_of_match[] = {
        { .compatible = "google,cros-ec-keyb" },
@@ -754,6 +768,7 @@ static struct platform_driver cros_ec_keyb_driver = {
        .driver = {
                .name = "cros-ec-keyb",
                .of_match_table = of_match_ptr(cros_ec_keyb_of_match),
+               .acpi_match_table = ACPI_PTR(cros_ec_keyb_acpi_match),
                .pm = &cros_ec_keyb_pm_ops,
        },
 };