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

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Submitter Rafał Miłecki
Date Sept. 9, 2012, 2:32 p.m.
Message ID <1347201121-20590-1-git-send-email-zajec5@gmail.com>
Download mbox | patch
Permalink /patch/182624/
State New
Headers show

Comments

Rafał Miłecki - Sept. 9, 2012, 2:32 p.m.
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.
At this point it doesn't work yet, so it's marked as BROKEN.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
---
 drivers/mtd/nand/Kconfig                       |    8 ++
 drivers/mtd/nand/Makefile                      |    1 +
 drivers/mtd/nand/bcm47xxnflash/Makefile        |    3 +
 drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h |   20 +++++
 drivers/mtd/nand/bcm47xxnflash/main.c          |  106 ++++++++++++++++++++++++
 5 files changed, 138 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/nand/bcm47xxnflash/Makefile
 create mode 100644 drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h
 create mode 100644 drivers/mtd/nand/bcm47xxnflash/main.c
Artem Bityutskiy - Sept. 11, 2012, 10:22 a.m.
On Sun, 2012-09-09 at 16:32 +0200, Rafał Miłecki wrote:
> 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.
> At this point it doesn't work yet, so it's marked as BROKEN.
> 
> Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

Why should it be merged upstream as BROKEN and without
controller-specific drivers?
Rafał Miłecki - Sept. 11, 2012, 10:23 a.m.
2012/9/11 Artem Bityutskiy <dedekind1@gmail.com>:
> On Sun, 2012-09-09 at 16:32 +0200, Rafał Miłecki wrote:
>> 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.
>> At this point it doesn't work yet, so it's marked as BROKEN.
>>
>> Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
>
> Why should it be merged upstream as BROKEN and without
> controller-specific drivers?

I'll resend this in a patchset proving some basic functionality.
Rafał Miłecki - Sept. 11, 2012, 10:45 a.m.
2012/9/11 Artem Bityutskiy <dedekind1@gmail.com>:
> On Sun, 2012-09-09 at 16:32 +0200, Rafał Miłecki wrote:
>> 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.
>> At this point it doesn't work yet, so it's marked as BROKEN.
>>
>> Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
>
> Why should it be merged upstream as BROKEN and without
> controller-specific drivers?

Regarding question about BROKEN: because they will start building
after meeting changes coming from net tree during merge window. Right
now that driver doesn't compile :(
Artem Bityutskiy - Sept. 11, 2012, 11:02 a.m.
On Tue, 2012-09-11 at 12:45 +0200, Rafał Miłecki wrote:
> 2012/9/11 Artem Bityutskiy <dedekind1@gmail.com>:
> > On Sun, 2012-09-09 at 16:32 +0200, Rafał Miłecki wrote:
> >> 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.
> >> At this point it doesn't work yet, so it's marked as BROKEN.
> >>
> >> Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
> >
> > Why should it be merged upstream as BROKEN and without
> > controller-specific drivers?
> 
> Regarding question about BROKEN: because they will start building
> after meeting changes coming from net tree during merge window. Right
> now that driver doesn't compile :(

Usually it is solved by pulling the tree we depend on, but we need a
permanent branch for this, which will not be re-based.

Patch

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 8ca4176..7460ac2 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -489,6 +489,14 @@  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 "Support for NAND flash on BCMA bus"
+	depends on BCMA_NFLASH && BROKEN
+	help
+	  BCMA bus can have various flash memories attached, they are
+	  registered by bcma as platform devices. This enables driver for
+	  NAND flash memories.
+
 config MTD_NAND_PLATFORM
 	tristate "Support for generic platform NAND driver"
 	depends on HAS_IOMEM
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index d4b4d87..8aa55d8 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -51,5 +51,6 @@  obj-$(CONFIG_MTD_NAND_MPC5121_NFC)	+= mpc5121_nfc.o
 obj-$(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_BCM47XXNFLASH)	+= bcm47xxnflash/
 
 nand-objs := nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/bcm47xxnflash/Makefile b/drivers/mtd/nand/bcm47xxnflash/Makefile
new file mode 100644
index 0000000..1d0693a
--- /dev/null
+++ b/drivers/mtd/nand/bcm47xxnflash/Makefile
@@ -0,0 +1,3 @@ 
+bcm47xxnflash-y				+= main.o
+
+obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash.o
diff --git a/drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h b/drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h
new file mode 100644
index 0000000..692ea5f
--- /dev/null
+++ b/drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h
@@ -0,0 +1,20 @@ 
+#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;
+
+	unsigned curr_command;
+	int curr_page_addr;
+	int curr_column;
+};
+
+int bcm47xxnflash_nand_bcm4706_init(struct bcm47xxnflash *bcm47xxnflash);
+
+#endif /* BCM47XXNFLASH */
diff --git a/drivers/mtd/nand/bcm47xxnflash/main.c b/drivers/mtd/nand/bcm47xxnflash/main.c
new file mode 100644
index 0000000..a28feb3
--- /dev/null
+++ b/drivers/mtd/nand/bcm47xxnflash/main.c
@@ -0,0 +1,106 @@ 
+/*
+ * 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;
+	}
+
+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);