linux-kernel - [PATCH v2] ACPI: LPSS: Use ACPI

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Date:   Sun, 10 Oct 2021 19:23:01 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: [PATCH v2] ACPI: LPSS: Use ACPI_COMPANION() directly

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

The ACPI_HANDLE() macro returns the ACPI handle of the ACPI device
object returned by the ACPI_COMPANION() macro, so it is more
straightforward to call the latter directly instead of passing
the handle produced by the former to acpi_bus_get_device().

Modify the code accordingly (no intentional functional impact).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---

-> v2:
   * Set ret = 0 on successful return from lpss_reg_read().

---
 drivers/acpi/acpi_lpss.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Index: linux-pm/drivers/acpi/acpi_lpss.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpi_lpss.c
+++ linux-pm/drivers/acpi/acpi_lpss.c
@@ -712,14 +712,13 @@ static void __lpss_reg_write(u32 val, st
 
 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 {
-	struct acpi_device *adev;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	struct lpss_private_data *pdata;
 	unsigned long flags;
 	int ret;
 
-	ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
-	if (WARN_ON(ret))
-		return ret;
+	if (WARN_ON(!adev))
+		return -ENODEV;
 
 	spin_lock_irqsave(&dev->power.lock, flags);
 	if (pm_runtime_suspended(dev)) {
@@ -732,6 +731,7 @@ static int lpss_reg_read(struct device *
 		goto out;
 	}
 	*val = __lpss_reg_read(pdata, reg);
+	ret = 0;
 
  out:
 	spin_unlock_irqrestore(&dev->power.lock, flags);
@@ -1266,7 +1266,8 @@ static int acpi_lpss_platform_notify(str
 	if (!id || !id->driver_data)
 		return 0;
 
-	if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
+	adev = ACPI_COMPANION(&pdev->dev);
+	if (!adev)
 		return 0;
 
 	pdata = acpi_driver_data(adev);