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-rw-r--r--drivers/nvmem/layouts.c201
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/nvmem/layouts.c b/drivers/nvmem/layouts.c
new file mode 100644
index 0000000000..6a6aa58369
--- /dev/null
+++ b/drivers/nvmem/layouts.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMEM layout bus handling
+ *
+ * Copyright (C) 2023 Bootlin
+ * Author: Miquel Raynal <miquel.raynal@bootlin.com
+ */
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+
+#include "internals.h"
+
+#define to_nvmem_layout_driver(drv) \
+ (container_of((drv), struct nvmem_layout_driver, driver))
+#define to_nvmem_layout_device(_dev) \
+ container_of((_dev), struct nvmem_layout, dev)
+
+static int nvmem_layout_bus_match(struct device *dev, struct device_driver *drv)
+{
+ return of_driver_match_device(dev, drv);
+}
+
+static int nvmem_layout_bus_probe(struct device *dev)
+{
+ struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);
+ struct nvmem_layout *layout = to_nvmem_layout_device(dev);
+
+ if (!drv->probe || !drv->remove)
+ return -EINVAL;
+
+ return drv->probe(layout);
+}
+
+static void nvmem_layout_bus_remove(struct device *dev)
+{
+ struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);
+ struct nvmem_layout *layout = to_nvmem_layout_device(dev);
+
+ return drv->remove(layout);
+}
+
+static struct bus_type nvmem_layout_bus_type = {
+ .name = "nvmem-layout",
+ .match = nvmem_layout_bus_match,
+ .probe = nvmem_layout_bus_probe,
+ .remove = nvmem_layout_bus_remove,
+};
+
+int nvmem_layout_driver_register(struct nvmem_layout_driver *drv)
+{
+ drv->driver.bus = &nvmem_layout_bus_type;
+
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(nvmem_layout_driver_register);
+
+void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(nvmem_layout_driver_unregister);
+
+static void nvmem_layout_release_device(struct device *dev)
+{
+ struct nvmem_layout *layout = to_nvmem_layout_device(dev);
+
+ of_node_put(layout->dev.of_node);
+ kfree(layout);
+}
+
+static int nvmem_layout_create_device(struct nvmem_device *nvmem,
+ struct device_node *np)
+{
+ struct nvmem_layout *layout;
+ struct device *dev;
+ int ret;
+
+ layout = kzalloc(sizeof(*layout), GFP_KERNEL);
+ if (!layout)
+ return -ENOMEM;
+
+ /* Create a bidirectional link */
+ layout->nvmem = nvmem;
+ nvmem->layout = layout;
+
+ /* Device model registration */
+ dev = &layout->dev;
+ device_initialize(dev);
+ dev->parent = &nvmem->dev;
+ dev->bus = &nvmem_layout_bus_type;
+ dev->release = nvmem_layout_release_device;
+ dev->coherent_dma_mask = DMA_BIT_MASK(32);
+ dev->dma_mask = &dev->coherent_dma_mask;
+ device_set_node(dev, of_fwnode_handle(of_node_get(np)));
+ of_device_make_bus_id(dev);
+ of_msi_configure(dev, dev->of_node);
+
+ ret = device_add(dev);
+ if (ret) {
+ put_device(dev);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id of_nvmem_layout_skip_table[] = {
+ { .compatible = "fixed-layout", },
+ {}
+};
+
+static int nvmem_layout_bus_populate(struct nvmem_device *nvmem,
+ struct device_node *layout_dn)
+{
+ int ret;
+
+ /* Make sure it has a compatible property */
+ if (!of_get_property(layout_dn, "compatible", NULL)) {
+ pr_debug("%s() - skipping %pOF, no compatible prop\n",
+ __func__, layout_dn);
+ return 0;
+ }
+
+ /* Fixed layouts are parsed manually somewhere else for now */
+ if (of_match_node(of_nvmem_layout_skip_table, layout_dn)) {
+ pr_debug("%s() - skipping %pOF node\n", __func__, layout_dn);
+ return 0;
+ }
+
+ if (of_node_check_flag(layout_dn, OF_POPULATED_BUS)) {
+ pr_debug("%s() - skipping %pOF, already populated\n",
+ __func__, layout_dn);
+
+ return 0;
+ }
+
+ /* NVMEM layout buses expect only a single device representing the layout */
+ ret = nvmem_layout_create_device(nvmem, layout_dn);
+ if (ret)
+ return ret;
+
+ of_node_set_flag(layout_dn, OF_POPULATED_BUS);
+
+ return 0;
+}
+
+struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
+{
+ return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
+}
+EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);
+
+/*
+ * Returns the number of devices populated, 0 if the operation was not relevant
+ * for this nvmem device, an error code otherwise.
+ */
+int nvmem_populate_layout(struct nvmem_device *nvmem)
+{
+ struct device_node *layout_dn;
+ int ret;
+
+ layout_dn = of_nvmem_layout_get_container(nvmem);
+ if (!layout_dn)
+ return 0;
+
+ /* Populate the layout device */
+ device_links_supplier_sync_state_pause();
+ ret = nvmem_layout_bus_populate(nvmem, layout_dn);
+ device_links_supplier_sync_state_resume();
+
+ of_node_put(layout_dn);
+ return ret;
+}
+
+void nvmem_destroy_layout(struct nvmem_device *nvmem)
+{
+ struct device *dev;
+
+ if (!nvmem->layout)
+ return;
+
+ dev = &nvmem->layout->dev;
+ of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
+ device_unregister(dev);
+}
+
+int nvmem_layout_bus_register(void)
+{
+ return bus_register(&nvmem_layout_bus_type);
+}
+
+void nvmem_layout_bus_unregister(void)
+{
+ bus_unregister(&nvmem_layout_bus_type);
+}