]> nv-tegra.nvidia Code Review - linux-2.6.git/commitdiff
[MTD] Platform RAM Driver
authorBen Dooks <ben@simtec.co.uk>
Mon, 24 Jan 2005 00:37:04 +0000 (00:37 +0000)
committerThomas Gleixner <tglx@mtd.linutronix.de>
Mon, 23 May 2005 09:33:47 +0000 (11:33 +0200)
Driver for generic RAM blocks which are exported by an platform_device
from the device driver system.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
drivers/mtd/maps/Kconfig
drivers/mtd/maps/Makefile
drivers/mtd/maps/plat-ram.c [new file with mode: 0644]
include/linux/mtd/plat-ram.h [new file with mode: 0644]

index 8480057eadb494da50bc1c1f428c80b3c6bfc795..7d21d432f38009ed0f399b9029dad7373ac62fb3 100644 (file)
@@ -1,5 +1,5 @@
 # drivers/mtd/maps/Kconfig
 # drivers/mtd/maps/Kconfig
-# $Id: Kconfig,v 1.42 2005/01/05 16:59:50 dwmw2 Exp $
+# $Id: Kconfig,v 1.43 2005/01/24 00:35:21 bjd Exp $
 
 menu "Mapping drivers for chip access"
        depends on MTD!=n
 
 menu "Mapping drivers for chip access"
        depends on MTD!=n
@@ -659,5 +659,15 @@ config MTD_SHARP_SL
        help
          This enables access to the flash chip on the Sharp SL Series of PDAs.
 
        help
          This enables access to the flash chip on the Sharp SL Series of PDAs.
 
+config MTD_PLATRAM
+       tristate "Map driver for platfrom device RAM (mtd-ram)"
+       depends on MTD
+       select MTD_RAM
+       help
+         Map driver for RAM areas described via the platform device
+         system.
+
+         This selection automatically selects the map_ram driver.
+
 endmenu
 
 endmenu
 
index 7ffe02b85301657650be057ab40949ce1fdec675..d2e6dcc870595c2256e26776a41e01064b9de3d5 100644 (file)
@@ -1,7 +1,7 @@
 #
 # linux/drivers/maps/Makefile
 #
 #
 # linux/drivers/maps/Makefile
 #
-# $Id: Makefile.common,v 1.23 2005/01/05 17:06:36 dwmw2 Exp $
+# $Id: Makefile.common,v 1.24 2005/01/24 00:35:21 bjd Exp $
 
 ifeq ($(CONFIG_MTD_COMPLEX_MAPPINGS),y)
 obj-$(CONFIG_MTD)              += map_funcs.o
 
 ifeq ($(CONFIG_MTD_COMPLEX_MAPPINGS),y)
 obj-$(CONFIG_MTD)              += map_funcs.o
@@ -71,3 +71,4 @@ obj-$(CONFIG_MTD_IXP2000)     += ixp2000.o
 obj-$(CONFIG_MTD_WRSBC8260)    += wr_sbc82xx_flash.o
 obj-$(CONFIG_MTD_DMV182)       += dmv182.o
 obj-$(CONFIG_MTD_SHARP_SL)     += sharpsl-flash.o
 obj-$(CONFIG_MTD_WRSBC8260)    += wr_sbc82xx_flash.o
 obj-$(CONFIG_MTD_DMV182)       += dmv182.o
 obj-$(CONFIG_MTD_SHARP_SL)     += sharpsl-flash.o
+obj-$(CONFIG_MTD_PLATRAM)      += plat-ram.o
diff --git a/drivers/mtd/maps/plat-ram.c b/drivers/mtd/maps/plat-ram.c
new file mode 100644 (file)
index 0000000..808f943
--- /dev/null
@@ -0,0 +1,286 @@
+/* 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 platfrom device based RAM map
+ *
+ * $Id: plat-ram.c,v 1.1 2005/01/24 00:37:02 bjd Exp $
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#define DEBUG
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/ioport.h>
+#include <linux/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 mtd_partition    *partitions;
+       struct resource         *area;
+       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 device *dev)
+{
+       return (struct platram_info *)dev_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 device *dev)
+{
+       struct platram_info *info = to_platram_info(dev);
+
+       dev_set_drvdata(dev, NULL);
+
+       dev_dbg(dev, "removing device\n");
+
+       if (info == NULL) 
+               return 0;
+
+       if (info->mtd) {
+#ifdef CONFIG_MTD_PARTITIONS
+               if (info->partitions) {
+                       del_mtd_partitions(info->mtd);
+                       kfree(info->partitions);
+               }
+#endif
+               del_mtd_device(info->mtd);
+               map_destroy(info->mtd);
+       }
+
+       /* ensure ram is left read-only */
+
+       platram_setrw(info, PLATRAM_RO);
+
+       /* release resources */
+
+       if (info->area) {
+               release_resource(info->area);
+               kfree(info->area);
+       }
+
+       if (info->map.virt != NULL)
+               iounmap(info->map.virt);
+       
+       kfree(info);
+
+       return 0;
+}
+
+/* platram_probe
+ *
+ * called from device drive system when a device matching our
+ * driver is found.
+*/
+
+static int platram_probe(struct device *dev)
+{
+       struct platform_device *pd = to_platform_device(dev);
+       struct platdata_mtd_ram *pdata;
+       struct platram_info *info;
+       struct resource *res;
+       int err = 0;
+
+       dev_dbg(dev, "probe entered\n");
+       
+       if (dev->platform_data == NULL) {
+               dev_err(dev, "no platform data supplied\n");
+               err = -ENOENT;
+               goto exit_error;
+       }
+
+       pdata = dev->platform_data;
+
+       info = kmalloc(sizeof(*info), GFP_KERNEL);
+       if (info == NULL) {
+               dev_err(dev, "no memory for flash info\n");
+               err = -ENOMEM;
+               goto exit_error;
+       }
+
+       memzero(info, sizeof(*info));
+       dev_set_drvdata(dev, info);
+
+       info->dev = dev;
+       info->pdata = pdata;
+
+       /* get the resource for the memory mapping */
+
+       res = platform_get_resource(pd, IORESOURCE_MEM, 0);
+
+       if (res == NULL) {
+               dev_err(dev, "no memory resource specified\n");
+               err = -ENOENT;
+               goto exit_free;
+       }
+
+       dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start);
+
+       /* setup map parameters */
+
+       info->map.phys = res->start;
+       info->map.size = (res->end - res->start) + 1;
+       info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->name;
+       info->map.bankwidth = pdata->bankwidth;
+
+       /* register our usage of the memory area */
+
+       info->area = request_mem_region(res->start, info->map.size, pd->name);
+       if (info->area == NULL) {
+               dev_err(dev, "failed to request memory region\n");
+               err = -EIO;
+               goto exit_free;
+       }
+
+       /* remap the memory area */
+
+       info->map.virt = ioremap(res->start, info->map.size);
+       dev_dbg(dev, "virt %p, %d bytes\n", info->map.virt, info->map.size);
+
+       if (info->map.virt == NULL) {
+               dev_err(dev, "failed to ioremap() region\n");
+               err = -EIO;
+               goto exit_free;
+       }
+
+       {
+               unsigned int *p = (unsigned int *)info->map.virt;
+               printk("%08x %08x %08x %08x\n",
+                      readl(p), readl(p+1), readl(p+2), readl(p+3));
+       }
+
+       simple_map_init(&info->map);
+
+       dev_dbg(dev, "initialised map, probing for mtd\n");
+
+       /* probe for the right mtd map driver */
+
+       info->mtd = do_map_probe("map_ram" , &info->map);
+       if (info->mtd == NULL) {
+               dev_err(dev, "failed to probe for map_ram\n");
+               err = -ENOMEM;
+               goto exit_free;
+       }
+
+       info->mtd->owner = THIS_MODULE;
+
+       platram_setrw(info, PLATRAM_RW);
+
+       /* check to see if there are any available partitions, or wether
+        * to add this device whole */
+
+#ifdef CONFIG_MTD_PARTITIONS
+       if (pdata->nr_partitions > 0) {
+               const char **probes = { NULL };
+
+               if (pdata->probes)
+                       probes = (const char **)pdata->probes;
+
+               err = parse_mtd_partitions(info->mtd, probes,
+                                          &info->partitions, 0);
+               if (err > 0) {
+                       err = add_mtd_partitions(info->mtd, info->partitions,
+                                                err);
+               }
+       }
+#endif /* CONFIG_MTD_PARTITIONS */
+
+       if (add_mtd_device(info->mtd)) {
+               dev_err(dev, "add_mtd_device() failed\n");
+               err = -ENOMEM;
+       }
+       
+       dev_info(dev, "registered mtd device\n");
+       return err;
+
+ exit_free:
+       platram_remove(dev);
+ exit_error:
+       return err;
+}
+
+/* device driver info */
+
+static struct device_driver platram_driver = {
+       .name           = "mtd-ram",
+       .bus            = &platform_bus_type,
+       .probe          = platram_probe,
+       .remove         = platram_remove,
+};
+
+/* module init/exit */
+
+static int __init platram_init(void)
+{
+       printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
+       return driver_register(&platram_driver);
+}
+
+static void __exit platram_exit(void)
+{
+       driver_unregister(&platram_driver);
+}
+
+module_init(platram_init);
+module_exit(platram_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_DESCRIPTION("MTD platform RAM map driver");
diff --git a/include/linux/mtd/plat-ram.h b/include/linux/mtd/plat-ram.h
new file mode 100644 (file)
index 0000000..2332eda
--- /dev/null
@@ -0,0 +1,35 @@
+/* linux/include/mtd/plat-ram.h
+ *
+ * (c) 2004 Simtec Electronics
+ *     http://www.simtec.co.uk/products/SWLINUX/
+ *     Ben Dooks <ben@simtec.co.uk>
+ *
+ * Generic platform device based RAM map
+ *
+ * $Id: plat-ram.h,v 1.2 2005/01/24 00:37:40 bjd Exp $
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __LINUX_MTD_PLATRAM_H
+#define __LINUX_MTD_PLATRAM_H __FILE__
+
+#define PLATRAM_RO (0)
+#define PLATRAM_RW (1)
+
+struct platdata_mtd_ram {
+       char                    *mapname;
+       char                   **probes;
+       struct mtd_partition    *partitions;
+       int                      nr_partitions;
+       int                      bankwidth;
+
+       /* control callbacks */
+
+       void    (*set_rw)(struct device *dev, int to);
+};
+
+#endif /* __LINUX_MTD_PLATRAM_H */