diff options
Diffstat (limited to 'drivers/mtd/maps/plat-ram.c')
| -rw-r--r-- | drivers/mtd/maps/plat-ram.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/mtd/maps/plat-ram.c b/drivers/mtd/maps/plat-ram.c new file mode 100644 index 000000000..4c921dce7 --- /dev/null +++ b/drivers/mtd/maps/plat-ram.c @@ -0,0 +1,220 @@ +// 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"); |