diff options
Diffstat (limited to 'drivers/nvmem/layouts.c')
| -rw-r--r-- | drivers/nvmem/layouts.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/nvmem/layouts.c b/drivers/nvmem/layouts.c new file mode 100644 index 000000000000..6a6aa58369ff --- /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); +} |