platform/chrome: cros_ec_lpc: Add MKBP events support over ACPI

This patch installs a notify handler to process MKBP events for EC
firmware directing them over ACPI.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index 89afad7..eeb187e 100644 (file)
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -227,9 +227,20 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
        return cnt;
 }
 
+static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
+{
+       struct cros_ec_device *ec_dev = data;
+
+       if (ec_dev->mkbp_event_supported && cros_ec_get_next_event(ec_dev) > 0)
+               blocking_notifier_call_chain(&ec_dev->event_notifier, 0,
+                                            ec_dev);
+}
+
 static int cros_ec_lpc_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
+       struct acpi_device *adev;
+       acpi_status status;
        struct cros_ec_device *ec_dev;
        u8 buf[2];
        int ret;
@@ -277,12 +288,33 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
                return ret;
        }
 
+       /*
+        * Connect a notify handler to process MKBP messages if we have a
+        * companion ACPI device.
+        */
+       adev = ACPI_COMPANION(dev);
+       if (adev) {
+               status = acpi_install_notify_handler(adev->handle,
+                                                    ACPI_ALL_NOTIFY,
+                                                    cros_ec_lpc_acpi_notify,
+                                                    ec_dev);
+               if (ACPI_FAILURE(status))
+                       dev_warn(dev, "Failed to register notifier %08x\n",
+                                status);
+       }
+
        return 0;
 }
 
 static int cros_ec_lpc_remove(struct platform_device *pdev)
 {
        struct cros_ec_device *ec_dev;
+       struct acpi_device *adev;
+
+       adev = ACPI_COMPANION(&pdev->dev);
+       if (adev)
+               acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
+                                          cros_ec_lpc_acpi_notify);
 
        ec_dev = platform_get_drvdata(pdev);
        cros_ec_remove(ec_dev);