This patch adds supports for SPI device enumeration and removal via
ACPI reconfiguration notifications that are send as a result of an
ACPI table load or unload operation.

Signed-off-by: Octavian Purdila <octavian.purd...@intel.com>
---
 drivers/spi/spi.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 87 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index de2f2f9..d6c5a9c 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1644,18 +1644,15 @@ static int acpi_spi_add_resource(struct acpi_resource 
*ares, void *data)
        return 1;
 }
 
-static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
-                                      void *data, void **return_value)
+static acpi_status acpi_register_spi_device(struct spi_master *master,
+                                           struct acpi_device *adev)
 {
-       struct spi_master *master = data;
        struct list_head resource_list;
-       struct acpi_device *adev;
        struct spi_device *spi;
        int ret;
 
-       if (acpi_bus_get_device(handle, &adev))
-               return AE_OK;
-       if (acpi_bus_get_status(adev) || !adev->status.present)
+       if (acpi_bus_get_status(adev) || !adev->status.present ||
+           acpi_device_enumerated(adev))
                return AE_OK;
 
        spi = spi_alloc_device(master);
@@ -1681,6 +1678,8 @@ static acpi_status acpi_spi_add_device(acpi_handle 
handle, u32 level,
        if (spi->irq < 0)
                spi->irq = acpi_dev_gpio_irq_get(adev, 0);
 
+       adev->flags.visited = true;
+
        adev->power.flags.ignore_parent = true;
        strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias));
        if (spi_add_device(spi)) {
@@ -1693,6 +1692,18 @@ static acpi_status acpi_spi_add_device(acpi_handle 
handle, u32 level,
        return AE_OK;
 }
 
+static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
+                                      void *data, void **return_value)
+{
+       struct spi_master *master = data;
+       struct acpi_device *adev;
+
+       if (acpi_bus_get_device(handle, &adev))
+               return AE_OK;
+
+       return acpi_register_spi_device(master, adev);
+}
+
 static void acpi_register_spi_devices(struct spi_master *master)
 {
        acpi_status status;
@@ -3104,6 +3115,73 @@ static struct notifier_block spi_of_notifier = {
 extern struct notifier_block spi_of_notifier;
 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
 
+#if IS_ENABLED(CONFIG_ACPI)
+static int spi_acpi_master_match(struct device *dev, const void *data)
+{
+       return ACPI_COMPANION(dev->parent) == data;
+}
+
+static int spi_acpi_device_match(struct device *dev, void *data)
+{
+       return ACPI_COMPANION(dev) == data;
+}
+
+static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device 
*adev)
+{
+       struct device *dev;
+
+       dev = class_find_device(&spi_master_class, NULL, adev,
+                               spi_acpi_master_match);
+       if (!dev)
+               return NULL;
+
+       return container_of(dev, struct spi_master, dev);
+}
+
+static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device 
*adev)
+{
+       struct device *dev;
+
+       dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match);
+
+       return dev ? to_spi_device(dev) : NULL;
+}
+
+static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
+                          void *arg)
+{
+       struct acpi_device *adev = arg;
+       struct spi_master *master;
+       struct spi_device *spi;
+
+       switch (value) {
+       case ACPI_RECONFIG_DEVICE_ADD:
+               master = acpi_spi_find_master_by_adev(adev->parent);
+               if (!master)
+                       break;
+
+               acpi_register_spi_device(master, adev);
+               put_device(&master->dev);
+               break;
+       case ACPI_RECONFIG_DEVICE_REMOVE:
+               spi = acpi_spi_find_device_by_adev(adev);
+               if (!spi)
+                       break;
+
+               spi_unregister_device(spi);
+               put_device(&spi->dev);
+       }
+
+       return NOTIFY_OK;
+}
+
+static struct notifier_block spi_acpi_notifier = {
+       .notifier_call = acpi_spi_notify,
+};
+#else
+extern struct notifier_block spi_acpi_notifier;
+#endif
+
 static int __init spi_init(void)
 {
        int     status;
@@ -3124,6 +3202,8 @@ static int __init spi_init(void)
 
        if (IS_ENABLED(CONFIG_OF_DYNAMIC))
                WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
+       if (IS_ENABLED(CONFIG_ACPI))
+               WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
 
        return 0;
 
-- 
1.9.1

Reply via email to