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// SPDX-License-Identifier: GPL-2.0-or-later
/* drivers/mtd/maps/plat-ram.c
*
* (c) 2004-2005 Simtec Electronics
* http://www.simtec.co.uk/products/SWLINUX/
* Ben Dooks <ben@simtec.co.uk>
*
* Generic platform device based RAM map
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/plat-ram.h>
#include <asm/io.h>
/* private structure for each mtd platform ram device created */
struct platram_info {
struct device *dev;
struct mtd_info *mtd;
struct map_info map;
struct platdata_mtd_ram *pdata;
};
/* to_platram_info()
*
* device private data to struct platram_info conversion
*/
static inline struct platram_info *to_platram_info(struct platform_device *dev)
{
return platform_get_drvdata(dev);
}
/* platram_setrw
*
* call the platform device's set rw/ro control
*
* to = 0 => read-only
* = 1 => read-write
*/
static inline void platram_setrw(struct platram_info *info, int to)
{
if (info->pdata == NULL)
return;
if (info->pdata->set_rw != NULL)
(info->pdata->set_rw)(info->dev, to);
}
/* platram_remove
*
* called to remove the device from the driver's control
*/
static int platram_remove(struct platform_device *pdev)
{
struct platram_info *info = to_platram_info(pdev);
dev_dbg(&pdev->dev, "removing device\n");
if (info == NULL)
return 0;
if (info->mtd) {
mtd_device_unregister(info->mtd);
map_destroy(info->mtd);
}
/* ensure ram is left read-only */
platram_setrw(info, PLATRAM_RO);
kfree(info);
return 0;
}
/* platram_probe
*
* called from device drive system when a device matching our
* driver is found.
*/
static int platram_probe(struct platform_device *pdev)
{
struct platdata_mtd_ram *pdata;
struct platram_info *info;
struct resource *res;
int err = 0;
dev_dbg(&pdev->dev, "probe entered\n");
if (dev_get_platdata(&pdev->dev) == NULL) {
dev_err(&pdev->dev, "no platform data supplied\n");
err = -ENOENT;
goto exit_error;
}
pdata = dev_get_platdata(&pdev->dev);
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (info == NULL) {
err = -ENOMEM;
goto exit_error;
}
platform_set_drvdata(pdev, info);
info->dev = &pdev->dev;
info->pdata = pdata;
/* get the resource for the memory mapping */
info->map.virt = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(info->map.virt)) {
err = PTR_ERR(info->map.virt);
goto exit_free;
}
dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,
(unsigned long long)res->start);
/* setup map parameters */
info->map.phys = res->start;
info->map.size = resource_size(res);
info->map.name = pdata->mapname != NULL ?
(char *)pdata->mapname : (char *)pdev->name;
info->map.bankwidth = pdata->bankwidth;
dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
simple_map_init(&info->map);
dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");
/* probe for the right mtd map driver
* supplied by the platform_data struct */
if (pdata->map_probes) {
const char * const *map_probes = pdata->map_probes;
for ( ; !info->mtd && *map_probes; map_probes++)
info->mtd = do_map_probe(*map_probes , &info->map);
}
/* fallback to map_ram */
else
info->mtd = do_map_probe("map_ram", &info->map);
if (info->mtd == NULL) {
dev_err(&pdev->dev, "failed to probe for map_ram\n");
err = -ENOMEM;
goto exit_free;
}
info->mtd->dev.parent = &pdev->dev;
platram_setrw(info, PLATRAM_RW);
/* check to see if there are any available partitions, or whether
* to add this device whole */
err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,
pdata->partitions,
pdata->nr_partitions);
if (err) {
dev_err(&pdev->dev, "failed to register mtd device\n");
goto exit_free;
}
dev_info(&pdev->dev, "registered mtd device\n");
if (pdata->nr_partitions) {
/* add the whole device. */
err = mtd_device_register(info->mtd, NULL, 0);
if (err) {
dev_err(&pdev->dev,
"failed to register the entire device\n");
goto exit_free;
}
}
return 0;
exit_free:
platram_remove(pdev);
exit_error:
return err;
}
/* device driver info */
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:mtd-ram");
static struct platform_driver platram_driver = {
.probe = platram_probe,
.remove = platram_remove,
.driver = {
.name = "mtd-ram",
},
};
module_platform_driver(platram_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("MTD platform RAM map driver");
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