Re: [PATCH v2 1/3] ACPI / utils: Introduce acpi_dev_get_dev_name()

Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> · Thu, 4 Jan 2018 18:47:56 -0600

On 01/04/2018 10:47 AM, Andy Shevchenko wrote:
Sometimes the user want to have device name of the match rather than
just checking if device present or not. To make life easier for such
users introduce acpi_dev_get_dev_name() helper based on code for
acpi_dev_present().

To be more consistent with the purpose rename

   struct acpi_dev_present_info  -> struct acpi_dev_match_info
   acpi_dev_present_cb()         -> acpi_dev_match_cb()

in the utils.c file.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
This works fine on a Dell 5585 where the default codec dai name needs to 
be updated based on the actual HID information, so
Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

the next patch does not apply directly however, and needs additional 
changes for the ES8316 machine driver. see the changes here: 
https://github.com/plbossart/sound/tree/topic/bytcht-acpi-fixes

It's probably best to let this patch go through the acpi tree, and the 
next one through Mark's tree once the first is merged and all the other 
Kconfig/acpi stuff is also in -next?

---
  drivers/acpi/utils.c    | 40 +++++++++++++++++++++++++++++++++-------
  include/acpi/acpi_bus.h |  1 +
  include/linux/acpi.h    |  6 ++++++
  3 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 9d49a1acebe3..1da9e986d510 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -737,16 +737,17 @@ bool acpi_dev_found(const char *hid)
  }
  EXPORT_SYMBOL(acpi_dev_found);
  
-struct acpi_dev_present_info {
+struct acpi_dev_match_info {
+	const char *dev_name;
  	struct acpi_device_id hid[2];
  	const char *uid;
  	s64 hrv;
  };
  
-static int acpi_dev_present_cb(struct device *dev, void *data)
+static int acpi_dev_match_cb(struct device *dev, void *data)
  {
  	struct acpi_device *adev = to_acpi_device(dev);
-	struct acpi_dev_present_info *match = data;
+	struct acpi_dev_match_info *match = data;
  	unsigned long long hrv;
  	acpi_status status;
  
@@ -757,6 +758,8 @@ static int acpi_dev_present_cb(struct device *dev, void *data)
  	    strcmp(adev->pnp.unique_id, match->uid)))
  		return 0;
  
+	match->dev_name = acpi_dev_name(adev);
+
  	if (match->hrv == -1)
  		return 1;
  
@@ -789,20 +792,43 @@ static int acpi_dev_present_cb(struct device *dev, void *data)
   */
  bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
  {
-	struct acpi_dev_present_info match = {};
+	struct acpi_dev_match_info match = {};
  	struct device *dev;
  
  	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
  	match.uid = uid;
  	match.hrv = hrv;
  
-	dev = bus_find_device(&acpi_bus_type, NULL, &match,
-			      acpi_dev_present_cb);
-
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
  	return !!dev;
  }
  EXPORT_SYMBOL(acpi_dev_present);
  
+/**
+ * acpi_dev_get_dev_name - Return device name of first match of ACPI device
+ * @hid: Hardware ID of the device.
+ * @uid: Unique ID of the device, pass NULL to not check _UID
+ * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
+ *
+ * Return device name if a matching device was present
+ * at the moment of invocation, or NULL otherwise.
+ *
+ * See additional information in acpi_dev_present() as well.
+ */
+const char *acpi_dev_get_dev_name(const char *hid, const char *uid, s64 hrv)
+{
+	struct acpi_dev_match_info match = {};
+	struct device *dev;
+
+	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	match.uid = uid;
+	match.hrv = hrv;
+
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+	return dev ? match.dev_name : NULL;
+}
+EXPORT_SYMBOL(acpi_dev_get_dev_name);
+
  /*
   * acpi_backlight= handling, this is done here rather then in video_detect.c
   * because __setup cannot be used in modules.
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 79287629c888..8883f5ebb6ce 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -90,6 +90,7 @@ acpi_evaluate_dsm_typed(acpi_handle handle, const guid_t *guid, u64 rev,
  
  bool acpi_dev_found(const char *hid);
  bool acpi_dev_present(const char *hid, const char *uid, s64 hrv);
+const char *acpi_dev_get_dev_name(const char *hid, const char *uid, s64 hrv);
  
  #ifdef CONFIG_ACPI
  
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 1922063f6894..d6576eec45d1 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -644,6 +644,12 @@ static inline bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
  	return false;
  }
  
+static inline
+const char *acpi_dev_get_dev_name(const char *hid, const char *uid, s64 hrv)
+{
+	return NULL;
+}
+
  static inline bool is_acpi_node(struct fwnode_handle *fwnode)
  {
  	return false;

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