acpi: amba: convert to using _PRP and fix _HID

Convert from the old _DSM indicated clocks to the newer _PRP method as
a staging point for final conversion to _DSD

Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>

1 files changed, 31 insertions, 129 deletions

diff --git a/drivers/amba/acpi.c b/drivers/amba/acpi.c
index 9a97cd8ad433..ae180757f335 100644
--- a/drivers/amba/acpi.c
+++ b/drivers/amba/acpi.c
@@ -25,102 +25,6 @@ struct acpi_amba_bus_info {
 	char *clk_name;
 };
 
-/* UUID: a706b112-bf0b-48d2-9fa3-95591a3c4c06 (randomly generated) */
-static const char acpi_amba_dsm_uuid[] = {
-	0xa7, 0x06, 0xb1, 0x12, 0xbf, 0x0b, 0x48, 0xd2,
-	0x9f, 0xa3, 0x95, 0x59, 0x1a, 0x3c, 0x4c, 0x06
-};
-
-/* acpi_amba_dsm_lookup()
- *
- * Helper to parse through ACPI _DSM object for a device. Each entry
- * has three fields.
- */
-int acpi_amba_dsm_lookup(acpi_handle handle,
-		const char *tag, int index,
-		struct acpi_amba_dsm_entry *entry)
-{
-	acpi_status status;
-	struct acpi_object_list input;
-	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object params[4];
-	union acpi_object *obj;
-	int len, match_count, i;
-
-	/* invalidate output in case there's no entry to supply */
-	entry->key = NULL;
-	entry->value = NULL;
-
-	if (!acpi_has_method(handle, "_DSM"))
-		return -ENOENT;
-
-	input.count = 4;
-	params[0].type = ACPI_TYPE_BUFFER;		/* UUID */
-	params[0].buffer.length = sizeof(acpi_amba_dsm_uuid);
-	params[0].buffer.pointer = (char *)acpi_amba_dsm_uuid;
-	params[1].type = ACPI_TYPE_INTEGER;		/* Revision */
-	params[1].integer.value = 1;
-	params[2].type = ACPI_TYPE_INTEGER;		/* Function # */
-	params[2].integer.value = 1;
-	params[3].type = ACPI_TYPE_PACKAGE;		/* Arguments */
-	params[3].package.count = 0;
-	params[3].package.elements = NULL;
-	input.pointer = params;
-
-	status = acpi_evaluate_object_typed(handle, "_DSM",
-			&input, &output, ACPI_TYPE_PACKAGE);
-	if (ACPI_FAILURE(status)) {
-		pr_err("failed to get _DSM package for this device\n");
-		return -ENOENT;
-	}
-
-	obj = (union acpi_object *)output.pointer;
-
-	/* parse 2 objects per entry */
-	match_count = 0;
-	for (i = 0; (i + 2) <= obj->package.count; i += 2) {
-		/* key must be a string */
-		len = obj->package.elements[i].string.length;
-		if (len <= 0)
-			continue;
-
-		/* check to see if this is the entry to return */
-		if (strncmp(tag, obj->package.elements[i].string.pointer,
-				len) != 0 ||
-				match_count < index) {
-			match_count++;
-			continue;
-		}
-
-		/* copy the key */
-		entry->key = kmalloc(len + 1, GFP_KERNEL);
-		strncpy(entry->key,
-				obj->package.elements[i].string.pointer,
-				len);
-		entry->key[len] = '\0';
-
-		/* value is a string with space-delimited fields if necessary */
-		len = obj->package.elements[i + 1].string.length;
-		if (len > 0) {
-			entry->value = kmalloc(len + 1, GFP_KERNEL);
-			strncpy(entry->value,
-				obj->package.elements[i+1].string.pointer,
-				len);
-			entry->value[len] = '\0';
-		}
-
-		break;
-	}
-
-	kfree(output.pointer);
-
-	if (entry->key == NULL)
-		return -ENOENT;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(acpi_amba_dsm_lookup);
-
 static int acpi_amba_add_resource(struct acpi_resource *ares, void *data)
 {
 	struct amba_device *dev = data;
@@ -157,43 +61,41 @@ static int acpi_amba_add_resource(struct acpi_resource *ares, void *data)
 static struct clk *acpi_amba_get_clk(acpi_handle handle, int index,
 		char **clk_name)
 {
-	struct acpi_amba_dsm_entry entry;
 	acpi_handle clk_handle;
 	struct acpi_device *adev, *clk_adev;
-	char *clk_path;
+	const char **clk_paths;
 	struct clk *clk = NULL;
-	int len;
+	int ret;
 
 	if (acpi_bus_get_device(handle, &adev)) {
 		pr_err("cannot get device from handle\n");
 		return NULL;
 	}
 
-	/* key=value format for clocks is:
-	 *	"clock-name"="apb_pclk \\_SB.CLK0"
-	 */
-	if (acpi_amba_dsm_lookup(handle, "clock-name", index, &entry) != 0)
+	/* Get number of entries */
+	ret = acpi_dev_get_property_array_string(adev, "clocks", NULL, 0);
+
+	if ((ret < 0) || (index >= ret))
 		return NULL;
 
+	clk_paths = kzalloc(sizeof(*clk_paths) * ret, GFP_KERNEL);
+
 	/* look under the clock device for the clock that matches the entry */
-	*clk_name = NULL;
-	len = strcspn(entry.value, " ");
-	if (len > 0 && (len + 1) < strlen(entry.value)) {
-		clk_path = entry.value + len + 1;
-		*clk_name = kmalloc(len + 1, GFP_KERNEL);
-		strncpy(*clk_name, entry.value, len);
-		(*clk_name)[len] = '\0';
-		if (ACPI_FAILURE(
-			acpi_get_handle(NULL, clk_path, &clk_handle)) == 0 &&
-			acpi_bus_get_device(clk_handle, &clk_adev) == 0)
-			clk = clk_get_sys(dev_name(&clk_adev->dev), *clk_name);
-	} else
-		pr_err("Invalid clock-name value format '%s' for %s\n",
-				entry.value, dev_name(&adev->dev));
-
-	kfree(entry.key);
-	kfree(entry.value);
+	ret = acpi_dev_get_property_array_string(adev, "clocks", clk_paths,
+			ret);
+
+	/* Locate the acpi_device from the device name */
+	acpi_get_handle(NULL, (acpi_string)clk_paths[index], &clk_handle);
+	if (!clk_handle)
+		goto error;
+	acpi_bus_get_device(clk_handle, &clk_adev);
+	if (!clk_adev)
+		goto error;
 
+	clk = clk_get_sys(dev_name(&clk_adev->dev), NULL);
+
+error:
+	kfree(clk_paths);
 	return clk;
 }
 
@@ -204,14 +106,6 @@ static void acpi_amba_register_clocks(struct acpi_device *adev,
 	int i;
 	char *clk_name;
 
-	if (default_clk) {
-		/* for amba_get_enable_pclk() ... */
-		clk_register_clkdev(default_clk, default_clk_name,
-				dev_name(&adev->dev));
-		/* for devm_clk_get() ... */
-		clk_register_clkdev(default_clk, NULL, dev_name(&adev->dev));
-	}
-
 	for (i = 0;; i++) {
 		clk_name = NULL;
 		clk = acpi_amba_get_clk(ACPI_HANDLE(&adev->dev), i, &clk_name);
@@ -222,6 +116,14 @@ static void acpi_amba_register_clocks(struct acpi_device *adev,
 
 		kfree(clk_name);
 	}
+
+	if (default_clk) {
+		/* for amba_get_enable_pclk() ... */
+		clk_register_clkdev(default_clk, default_clk_name,
+				dev_name(&adev->dev));
+		/* for devm_clk_get() ... */
+		clk_register_clkdev(default_clk, NULL, dev_name(&adev->dev));
+	}
 }
 
 /* acpi_amba_add_device()
@@ -309,7 +211,7 @@ static int acpi_amba_bus_probe(struct platform_device *pdev)
 }
 
 static const struct acpi_device_id amba_bus_acpi_match[] = {
-	{ "AMBA0000", 0 },
+	{ "LNRO001A", 0 },
 	{ },
 };