platform/x86: serial-multi-instantiate: Improve autodetection

Instead of calling specific resource counter, let just probe each
of the type and see what it says. Return -ENOENT if no resources
found.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220709211653.18938-1-andriy.shevchenko@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/serial-multi-instantiate.c b/drivers/platform/x86/serial-multi-instantiate.c
index 1e8063b..366087a 100644 (file)
--- a/drivers/platform/x86/serial-multi-instantiate.c
+++ b/drivers/platform/x86/serial-multi-instantiate.c
@@ -100,7 +100,7 @@ static int smi_spi_probe(struct platform_device *pdev, struct acpi_device *adev,
        if (ret < 0)
                return ret;
        else if (!ret)
-               return -ENODEV;
+               return -ENOENT;
 
        count = ret;
 
@@ -184,7 +184,7 @@ static int smi_i2c_probe(struct platform_device *pdev, struct acpi_device *adev,
        if (ret < 0)
                return ret;
        else if (!ret)
-               return -ENODEV;
+               return -ENOENT;
 
        count = ret;
 
@@ -232,6 +232,7 @@ static int smi_probe(struct platform_device *pdev)
        const struct smi_node *node;
        struct acpi_device *adev;
        struct smi *smi;
+       int ret;
 
        adev = ACPI_COMPANION(dev);
        if (!adev)
@@ -255,15 +256,21 @@ static int smi_probe(struct platform_device *pdev)
        case SMI_SPI:
                return smi_spi_probe(pdev, adev, smi, node->instances);
        case SMI_AUTO_DETECT:
-               if (i2c_acpi_client_count(adev) > 0)
-                       return smi_i2c_probe(pdev, adev, smi, node->instances);
-               else
-                       return smi_spi_probe(pdev, adev, smi, node->instances);
+               /*
+                * For backwards-compatibility with the existing nodes I2C
+                * is checked first and if such entries are found ONLY I2C
+                * devices are created. Since some existing nodes that were
+                * already handled by this driver could also contain unrelated
+                * SpiSerialBus nodes that were previously ignored, and this
+                * preserves that behavior.
+                */
+               ret = smi_i2c_probe(pdev, adev, smi, node->instances);
+               if (ret != -ENOENT)
+                       return ret;
+               return smi_spi_probe(pdev, adev, smi, node->instances);
        default:
                return -EINVAL;
        }
-
-       return 0; /* never reached */
 }
 
 static int smi_remove(struct platform_device *pdev)