[PATCH 2/2] maps/mtd-ram: add an of-platform driver

Wolfram Sang
2009-02-20T16:15:19Z

Create an of-aware driver using the now exported generic functions from
plat-ram.c. A typical oftree snipplet for it looks like this:

sram@04e00000 {
compatible = "mtd-ram";
reg = <0x04e00000 0x00200000>;
bank-width = <2>;
};

Partitions on this device are not yet supported. Tested on a
phyCORE-MPC5200B-IO.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
---
drivers/mtd/maps/Kconfig | 6 ++
drivers/mtd/maps/Makefile | 1 +
drivers/mtd/maps/of-ram.c | 120 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 127 insertions(+), 0 deletions(-)
create mode 100644 drivers/mtd/maps/of-ram.c

diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index 0225cbb..b238b6d 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -551,5 +551,11 @@ config MTD_PLATRAM

This selection automatically selects the map_ram driver.

+config MTD_OFRAM
+ tristate "Map driver for of-device RAM (mtd-ram)"
+ depends on MTD_PLATRAM && OF
+ help
+ Map driver for RAM areas described via the of-device
+ system.
endmenu

diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
index 6d9ba35..f8e3908 100644
--- a/drivers/mtd/maps/Makefile
+++ b/drivers/mtd/maps/Makefile
@@ -58,6 +58,7 @@ 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
+obj-$(CONFIG_MTD_OFRAM) += of-ram.o
obj-$(CONFIG_MTD_OMAP_NOR) += omap_nor.o
obj-$(CONFIG_MTD_INTEL_VR_NOR) += intel_vr_nor.o
obj-$(CONFIG_MTD_BFIN_ASYNC) += bfin-async-flash.o
diff --git a/drivers/mtd/maps/of-ram.c b/drivers/mtd/maps/of-ram.c
new file mode 100644
index 0000000..4d334a9
--- /dev/null
+++ b/drivers/mtd/maps/of-ram.c
@@ -0,0 +1,120 @@
+/*
+ * drivers/mtd/maps/of-ram.c
+ *
+ * Generic of device based RAM map
+ *
+ * Copyright (C) 2009 Wolfram Sang, Pengutronix
+ *
+ * Using plat-ram.c by Ben Dooks
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/mtd/plat-ram.h>
+
+static int of_ram_probe(struct of_device *op, const struct of_device_id *match)
+{
+ struct platdata_mtd_ram *pdata;
+ struct resource *resource;
+ const char *name;
+ const u32 *bankwidth;
+ int ret = -ENOMEM;
+
+ pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ goto bad0;
+ op->dev.platform_data = pdata;
+
+ name = of_get_property(op->node, "name", NULL);
+ if (!name) {
+ ret = -ENOENT;
+ dev_dbg(&op->dev, "could not get node name\n");
+ goto bad1;
+ }
+
+ resource = kzalloc(sizeof(struct resource), GFP_KERNEL);
+ if (!resource)
+ goto bad1;
+
+ if (of_address_to_resource(op->node, 0, resource)) {
+ ret = -ENXIO;
+ dev_dbg(&op->dev, "could not create resource\n");
+ goto bad2;
+ }
+
+ bankwidth = of_get_property(op->node, "bank-width", NULL);
+ if (*bankwidth == 0) {
+ ret = -ENOENT;
+ dev_dbg(&op->dev, "bank width not set\n");
+ goto bad2;
+ }
+ pdata->bankwidth = *bankwidth;
+
+ ret = __platram_probe(&op->dev, name, resource, pdata);
+ kfree(resource);
+
+ if (ret)
+ goto bad1;
+
+ return 0;
+
+ bad2:
+ kfree(resource);
+ bad1:
+ op->dev.platform_data = NULL;
+ kfree(pdata);
+ bad0:
+ return ret;
+}
+
+static int of_ram_remove(struct of_device *op)
+{
+ int ret;
+ struct platdata_mtd_ram *pdata = op->dev.platform_data;
+
+ ret = __platram_remove(&op->dev);
+ op->dev.platform_data = NULL;
+ kfree(pdata);
+ return ret;
+}
+
+static struct of_device_id of_ram_match[] = {
+ { .compatible = "mtd-ram", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_ram_match);
+
+static struct of_platform_driver of_ram_driver = {
+ .owner = THIS_MODULE,
+ .name = "of-ram",
+ .match_table = of_ram_match,
+ .probe = of_ram_probe,
+ .remove = of_ram_remove,
+};
+
+static int __init of_ram_init(void)
+{
+ return of_register_platform_driver(&of_ram_driver);
+}
+
+static void __exit of_ram_exit(void)
+{
+ of_unregister_platform_driver(&of_ram_driver);
+}
+
+module_init(of_ram_init);
+module_exit(of_ram_exit);
+
+MODULE_AUTHOR("Wolfram Sang");
+MODULE_DESCRIPTION("MTD OF RAM map driver");
+MODULE_LICENSE("GPL v2");
--
1.5.6.5