linux-kernel - [PATCH V3 05/11] ACPI: check and enumerate CMOS RTC devices explicitly

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Date:	Mon, 17 Mar 2014 01:03:11 +0800
From:	Zhang Rui <rui.zhang@...el.com>
To:	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	bhelgaas@...gle.com, matthew.garrett@...ula.com,
	rafael.j.wysocki@...el.com, dmitry.torokhov@...il.com,
	Zhang Rui <rui.zhang@...el.com>
Subject: [PATCH V3 05/11] ACPI: check and enumerate CMOS RTC devices explicitly

For CMOS RTC devices, the acpi pnp scan handler does not work because
there is already a cmos rtc scan handler installed, thus we need to
check those devices and enumerate them to PNP bus explicitly.
Plus, the cmos rtc scan handler needs to return 1 so that it will not
be enumerated to platform bus.

Note: the CMOS RTC device id is not removed from ACPI pnp scan handler
      id list, thus, if cmos rtc scan handler is compiled out, the ACPI
      pnp scan handler will be attached to the CMOS RTC devices instead,
      to prevent these devices from being created to platform bus.

Signed-off-by: Zhang Rui <rui.zhang@...el.com>
---
 drivers/acpi/acpi_cmos_rtc.c |    2 +-
 drivers/acpi/acpi_pnp.c      |   22 +++++++++++++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/acpi_cmos_rtc.c b/drivers/acpi/acpi_cmos_rtc.c
index 84190ed..a19b0b3 100644
--- a/drivers/acpi/acpi_cmos_rtc.c
+++ b/drivers/acpi/acpi_cmos_rtc.c
@@ -70,7 +70,7 @@ static int acpi_install_cmos_rtc_space_handler(struct acpi_device *adev,
 		return -ENODEV;
 	}
 
-	return 0;
+	return 1;
 }
 
 static void acpi_remove_cmos_rtc_space_handler(struct acpi_device *adev)
diff --git a/drivers/acpi/acpi_pnp.c b/drivers/acpi/acpi_pnp.c
index 2a7f86f..6fa482a 100644
--- a/drivers/acpi/acpi_pnp.c
+++ b/drivers/acpi/acpi_pnp.c
@@ -349,9 +349,29 @@ static struct acpi_scan_handler acpi_pnp_handler = {
 	.attach = acpi_pnp_scan_handler_attach,
 };
 
+/*
+ * For CMOS RTC devices, the acpi pnp spcan handler does not work because
+ * there is already a cmos rtc scan handler installed, thus we need to
+ * check those devices and enumerate them to PNP bus explicitly.
+ */
+static int is_cmos_rtc_device(struct acpi_device *adev)
+{
+	struct acpi_device_id ids[] = {
+		{ "PNP0B00" },
+		{ "PNP0B01" },
+		{ "PNP0B02" },
+		{""},
+	};
+	return !acpi_match_device_ids(adev, ids);
+}
+
 bool acpi_is_pnp_device(struct acpi_device *device)
 {
-	return !!(device->handler == &acpi_pnp_handler);
+	if (device->handler == &acpi_pnp_handler)
+		return true;
+	if (is_cmos_rtc_device(device))
+		return true;
+	return false;
 }
 EXPORT_SYMBOL_GPL(acpi_is_pnp_device);
 
-- 
1.7.9.5

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