mtd: prepare place for BCMA NAND flash driver(s)

BCMA bus can contain NAND flash memory, it's registered in system as
platform device. This adds required hooks and place for controler
specific drivers.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

drivers/mtd/nand/Kconfig

@@ -460,6 +460,15 @@ config MTD_NAND_GPMI_NAND
 	 block, such as SD card. So pay attention to it when you enable
 	 the GPMI.
 
+config MTD_NAND_BCM47XXNFLASH
+	tristate "R/O support for NAND flash on BCMA bus"
+	depends on BCMA_NFLASH
+	help
+	  BCMA bus can have various flash memories attached, they are
+	  registered by bcma as platform devices. This enables driver for
+	  NAND flash memories. For now only read mode for BCM4706 is
+	  implemented.
+
 config MTD_NAND_PLATFORM
 	tristate "Support for generic platform NAND driver"
 	depends on HAS_IOMEM

drivers/mtd/nand/Makefile

@@ -54,5 +54,6 @@ obj-$(CONFIG_MTD_NAND_RICOH)		+= r852.o
 obj-$(CONFIG_MTD_NAND_JZ4740)		+= jz4740_nand.o
 obj-$(CONFIG_MTD_NAND_GPMI_NAND)	+= gpmi-nand/
 obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
+obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
 
 nand-objs := nand_base.o nand_bbt.o

drivers/mtd/nand/bcm47xxnflash/Makefile

@@ -0,0 +1,3 @@
+bcm47xxnflash-y				+= main.o
+
+obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash.o

drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h

@@ -0,0 +1,14 @@
+#ifndef __BCM47XXNFLASH_H
+#define __BCM47XXNFLASH_H
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+
+struct bcm47xxnflash {
+	struct bcma_drv_cc *cc;
+
+	struct nand_chip nand_chip;
+	struct mtd_info mtd;
+};
+
+#endif /* BCM47XXNFLASH */

drivers/mtd/nand/bcm47xxnflash/main.c

@@ -0,0 +1,108 @@
+/*
+ * BCM47XX NAND flash driver
+ *
+ * Copyright (C) 2012 Rafał Miłecki <zajec5@gmail.com>
+ *
+ * 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/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/bcma/bcma.h>
+
+#include "bcm47xxnflash.h"
+
+MODULE_DESCRIPTION("NAND flash driver for BCMA bus");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rafał Miłecki");
+
+static const char *probes[] = { "bcm47xxpart", NULL };
+
+static int bcm47xxnflash_probe(struct platform_device *pdev)
+{
+	struct bcma_nflash *nflash = dev_get_platdata(&pdev->dev);
+	struct bcm47xxnflash *b47n;
+	int err = 0;
+
+	b47n = kzalloc(sizeof(*b47n), GFP_KERNEL);
+	if (!b47n) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	b47n->nand_chip.priv = b47n;
+	b47n->mtd.owner = THIS_MODULE;
+	b47n->mtd.priv = &b47n->nand_chip; /* Required */
+	b47n->cc = container_of(nflash, struct bcma_drv_cc, nflash);
+
+	if (0) {
+		/* TODO: init device */
+	} else {
+		pr_err("Device not supported\n");
+		err = -ENOTSUPP;
+	}
+	if (err) {
+		pr_err("Initialization failed: %d\n", err);
+		goto err_init;
+	}
+
+	err = mtd_device_parse_register(&b47n->mtd, probes, NULL, NULL, 0);
+	if (err) {
+		pr_err("Failed to register MTD device: %d\n", err);
+		goto err_dev_reg;
+	}
+
+	return 0;
+
+err_dev_reg:
+err_init:
+	kfree(b47n);
+out:
+	return err;
+}
+
+static int __devexit bcm47xxnflash_remove(struct platform_device *pdev)
+{
+	struct bcma_nflash *nflash = dev_get_platdata(&pdev->dev);
+
+	if (nflash->mtd)
+		mtd_device_unregister(nflash->mtd);
+
+	return 0;
+}
+
+static struct platform_driver bcm47xxnflash_driver = {
+	.remove = __devexit_p(bcm47xxnflash_remove),
+	.driver = {
+		.name = "bcma_nflash",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init bcm47xxnflash_init(void)
+{
+	int err;
+
+	/*
+	 * Platform device "bcma_nflash" exists on SoCs and is registered very
+	 * early, it won't be added during runtime (use platform_driver_probe).
+	 */
+	err = platform_driver_probe(&bcm47xxnflash_driver, bcm47xxnflash_probe);
+	if (err)
+		pr_err("Failed to register serial flash driver: %d\n", err);
+
+	return err;
+}
+
+static void __exit bcm47xxnflash_exit(void)
+{
+	platform_driver_unregister(&bcm47xxnflash_driver);
+}
+
+module_init(bcm47xxnflash_init);
+module_exit(bcm47xxnflash_exit);