[PATCH v3 06/23] ata: libahci_platform: Convert to using platform devm-ioremap methods

Serge Semin
2022-05-11T23:18:41Z

Currently the IOMEM AHCI registers space is mapped by means of the
two functions invocation: platform_get_resource() is used to get the very
first memory resource and devm_ioremap_resource() is called to remap that
resource. Device-managed kernel API provides a handy wrapper to perform
the same in single function call: devm_platform_ioremap_resource().

While at it seeing many AHCI platform drivers rely on having the AHCI CSR
space marked with "ahci" name let's first try to find and remap the CSR
IO-mem with that name and only if it fails fallback to getting the very
first registers space platform resource.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>

---

Changelog v2:
- Check whether there is "ahhi" reg resource before using the
devm_platform_ioremap_resource_byname() method in order to prevent a
false error message printed in the log (@Damien)
- Slightly update the patch title due to the change above and to be more
specific that the platform device managed methods are utilized.
---
drivers/ata/libahci_platform.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index f7f9bfcfc164..8c9fbcc3043b 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -404,8 +404,14 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,

devres_add(dev, hpriv);

- hpriv->mmio = devm_ioremap_resource(dev,
- platform_get_resource(pdev, IORESOURCE_MEM, 0));
+ /*
+ * If the DT provided an "ahci" named resource, use it. Otherwise,
+ * fallback to using the default first resource for the device node.
+ */
+ if (platform_get_resource_byname(pdev, IORESOURCE_MEM, "ahci"))
+ hpriv->mmio = devm_platform_ioremap_resource_byname(pdev, "ahci");
+ else
+ hpriv->mmio = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hpriv->mmio)) {
rc = PTR_ERR(hpriv->mmio);
goto err_out;
--
2.35.1