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path: root/drivers/mtd/maps/plat-ram.c
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Diffstat (limited to 'drivers/mtd/maps/plat-ram.c')
-rw-r--r--drivers/mtd/maps/plat-ram.c220
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 0000000000..4c921dce73
--- /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");