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1// SPDX-License-Identifier: GPL-2.02/*3 * NVMEM layout bus handling4 *5 * Copyright (C) 2023 Bootlin6 * Author: Miquel Raynal <miquel.raynal@bootlin.com7 */8 9#include <linux/device.h>10#include <linux/dma-mapping.h>11#include <linux/nvmem-consumer.h>12#include <linux/nvmem-provider.h>13#include <linux/of.h>14#include <linux/of_device.h>15#include <linux/of_irq.h>16 17#include "internals.h"18 19#define to_nvmem_layout_driver(drv) \20 (container_of_const((drv), struct nvmem_layout_driver, driver))21#define to_nvmem_layout_device(_dev) \22 container_of((_dev), struct nvmem_layout, dev)23 24static int nvmem_layout_bus_match(struct device *dev, const struct device_driver *drv)25{26 return of_driver_match_device(dev, drv);27}28 29static int nvmem_layout_bus_probe(struct device *dev)30{31 struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);32 struct nvmem_layout *layout = to_nvmem_layout_device(dev);33 34 if (!drv->probe || !drv->remove)35 return -EINVAL;36 37 return drv->probe(layout);38}39 40static void nvmem_layout_bus_remove(struct device *dev)41{42 struct nvmem_layout_driver *drv = to_nvmem_layout_driver(dev->driver);43 struct nvmem_layout *layout = to_nvmem_layout_device(dev);44 45 return drv->remove(layout);46}47 48static const struct bus_type nvmem_layout_bus_type = {49 .name = "nvmem-layout",50 .match = nvmem_layout_bus_match,51 .probe = nvmem_layout_bus_probe,52 .remove = nvmem_layout_bus_remove,53};54 55int __nvmem_layout_driver_register(struct nvmem_layout_driver *drv,56 struct module *owner)57{58 drv->driver.bus = &nvmem_layout_bus_type;59 drv->driver.owner = owner;60 61 return driver_register(&drv->driver);62}63EXPORT_SYMBOL_GPL(__nvmem_layout_driver_register);64 65void nvmem_layout_driver_unregister(struct nvmem_layout_driver *drv)66{67 driver_unregister(&drv->driver);68}69EXPORT_SYMBOL_GPL(nvmem_layout_driver_unregister);70 71static void nvmem_layout_release_device(struct device *dev)72{73 struct nvmem_layout *layout = to_nvmem_layout_device(dev);74 75 of_node_put(layout->dev.of_node);76 kfree(layout);77}78 79static int nvmem_layout_create_device(struct nvmem_device *nvmem,80 struct device_node *np)81{82 struct nvmem_layout *layout;83 struct device *dev;84 int ret;85 86 layout = kzalloc(sizeof(*layout), GFP_KERNEL);87 if (!layout)88 return -ENOMEM;89 90 /* Create a bidirectional link */91 layout->nvmem = nvmem;92 nvmem->layout = layout;93 94 /* Device model registration */95 dev = &layout->dev;96 device_initialize(dev);97 dev->parent = &nvmem->dev;98 dev->bus = &nvmem_layout_bus_type;99 dev->release = nvmem_layout_release_device;100 dev->coherent_dma_mask = DMA_BIT_MASK(32);101 dev->dma_mask = &dev->coherent_dma_mask;102 device_set_node(dev, of_fwnode_handle(of_node_get(np)));103 of_device_make_bus_id(dev);104 of_msi_configure(dev, dev->of_node);105 106 ret = device_add(dev);107 if (ret) {108 put_device(dev);109 return ret;110 }111 112 return 0;113}114 115static const struct of_device_id of_nvmem_layout_skip_table[] = {116 { .compatible = "fixed-layout", },117 {}118};119 120static int nvmem_layout_bus_populate(struct nvmem_device *nvmem,121 struct device_node *layout_dn)122{123 int ret;124 125 /* Make sure it has a compatible property */126 if (!of_property_present(layout_dn, "compatible")) {127 pr_debug("%s() - skipping %pOF, no compatible prop\n",128 __func__, layout_dn);129 return 0;130 }131 132 /* Fixed layouts are parsed manually somewhere else for now */133 if (of_match_node(of_nvmem_layout_skip_table, layout_dn)) {134 pr_debug("%s() - skipping %pOF node\n", __func__, layout_dn);135 return 0;136 }137 138 if (of_node_check_flag(layout_dn, OF_POPULATED_BUS)) {139 pr_debug("%s() - skipping %pOF, already populated\n",140 __func__, layout_dn);141 142 return 0;143 }144 145 /* NVMEM layout buses expect only a single device representing the layout */146 ret = nvmem_layout_create_device(nvmem, layout_dn);147 if (ret)148 return ret;149 150 of_node_set_flag(layout_dn, OF_POPULATED_BUS);151 152 return 0;153}154 155struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)156{157 return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");158}159EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);160 161/*162 * Returns the number of devices populated, 0 if the operation was not relevant163 * for this nvmem device, an error code otherwise.164 */165int nvmem_populate_layout(struct nvmem_device *nvmem)166{167 struct device_node *layout_dn;168 int ret;169 170 layout_dn = of_nvmem_layout_get_container(nvmem);171 if (!layout_dn)172 return 0;173 174 /* Populate the layout device */175 device_links_supplier_sync_state_pause();176 ret = nvmem_layout_bus_populate(nvmem, layout_dn);177 device_links_supplier_sync_state_resume();178 179 of_node_put(layout_dn);180 return ret;181}182 183void nvmem_destroy_layout(struct nvmem_device *nvmem)184{185 struct device *dev;186 187 if (!nvmem->layout)188 return;189 190 dev = &nvmem->layout->dev;191 of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);192 device_unregister(dev);193}194 195int nvmem_layout_bus_register(void)196{197 return bus_register(&nvmem_layout_bus_type);198}199 200void nvmem_layout_bus_unregister(void)201{202 bus_unregister(&nvmem_layout_bus_type);203}204