[PATCH] physmap-concat map platform driver

[PATCH] physmap-concat map platform driver

[Anton Vorontsov]

This is physmap-concat driver, which is plain sa1100-flash.c
with factored out arch-specific code. This driver is essential for
boards using multiple nonindentical chips on the board.

Signed-off-by: Anton Vorontsov <cbou@mail.ru>
---
 drivers/mtd/maps/Kconfig      |   13 ++
 drivers/mtd/maps/Makefile     |    1 +
 drivers/mtd/maps/physmapcc.c  |  385 +++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/physmapcc.h |   39 ++++
 4 files changed, 438 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/maps/physmapcc.c
 create mode 100644 include/linux/mtd/physmapcc.h

diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index b665e4a..9ed9eb5 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -101,6 +101,19 @@ config MTD_PMC_MSP_RAMROOT
 	  This provides support for the embedded root file system
           on PMC MSP devices.  This memory is mapped as a MTD block device.
 
+config MTD_PHYSMAP_CONCAT
+	tristate "Multiple flash devices in physical memory map"
+	depends on MTD
+	help
+	  This provides a 'mapping' driver which allows the NOR Flash and
+	  ROM driver code to communicate with chips which are mapped
+	  physically into the CPU's memory. You will need to configure
+	  the physical address and size of the flash chips on your
+	  particular board as well as the bus width.
+
+	  Note, this driver differs from standard PHYSMAP driver in
+	  sense that it supports multiple nonidentical flash chips.
+
 config MTD_SUN_UFLASH
 	tristate "Sun Microsystems userflash support"
 	depends on SPARC && MTD_CFI
diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
index 3acbb5d..cba3d33 100644
--- a/drivers/mtd/maps/Makefile
+++ b/drivers/mtd/maps/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_MTD_CEIVA)		+= ceiva.o
 obj-$(CONFIG_MTD_OCTAGON)	+= octagon-5066.o
 obj-$(CONFIG_MTD_PHYSMAP)	+= physmap.o
 obj-$(CONFIG_MTD_PHYSMAP_OF)	+= physmap_of.o
+obj-$(CONFIG_MTD_PHYSMAP_CONCAT)+= physmapcc.o
 obj-$(CONFIG_MTD_PMC_MSP_EVM)   += pmcmsp-flash.o
 obj-$(CONFIG_MTD_PMC_MSP_RAMROOT)+= pmcmsp-ramroot.o
 obj-$(CONFIG_MTD_PNC2000)	+= pnc2000.o
diff --git a/drivers/mtd/maps/physmapcc.c b/drivers/mtd/maps/physmapcc.c
new file mode 100644
index 0000000..0009f0d
--- /dev/null
+++ b/drivers/mtd/maps/physmapcc.c
@@ -0,0 +1,385 @@
+/*
+ * Generic configurable MTD map driver with concat support
+ *
+ * Based on sa1100-flash driver.
+ *
+ * Copyright (c) 2007 Anton Vorontsov <cbou@mail.ru>
+ * Copyright (c) 2000 Nicolas Pitre <nico@cam.org>
+ *
+ * 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/ioport.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/concat.h>
+#include <linux/mtd/physmapcc.h>
+
+struct physmapcc_subdev {
+	char name[16];
+	struct map_info map;
+	struct mtd_info *mtd;
+	struct platform_device *pdev;
+};
+
+struct physmapcc_drvdata {
+	struct mtd_partition *parts;
+	struct mtd_info *mtd;
+	int num_subdev;
+	unsigned int nr_parts;
+	struct physmapcc_subdev subdev[0];
+};
+
+static void physmapcc_set_vpp(struct map_info *map, int on)
+{
+	struct physmapcc_subdev *subdev = container_of(map,
+	                                         struct physmapcc_subdev, map);
+	struct physmapcc_platform_data *pdata = subdev->pdev->dev.platform_data;
+
+	pdata->set_vpp(on);
+
+	return;
+}
+
+static void physmapcc_destroy_subdev(struct physmapcc_subdev *subdev)
+{
+	if (subdev->mtd)
+		map_destroy(subdev->mtd);
+	if (subdev->map.virt)
+		iounmap(subdev->map.virt);
+	release_mem_region(subdev->map.phys, subdev->map.size);
+
+	return;
+}
+
+static int physmapcc_probe_subdev(struct physmapcc_subdev *subdev,
+                                  struct resource *res)
+{
+	struct physmapcc_platform_data *pdata = subdev->pdev->dev.platform_data;
+	unsigned long phys;
+	unsigned int size;
+	int ret;
+
+	phys = res->start;
+	size = res->end - phys + 1;
+
+	/*
+	 * Retrieve the bankwidth from the resource flags.
+	 */
+	subdev->map.bankwidth = res->flags & IORESOURCE_MEM_32BIT ? 4 : 2;
+
+	if (!request_mem_region(phys, size, subdev->name)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	if (pdata->set_vpp)
+		subdev->map.set_vpp = physmapcc_set_vpp;
+
+	subdev->map.phys = phys;
+	subdev->map.size = size;
+	subdev->map.virt = ioremap(phys, size);
+	if (!subdev->map.virt) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	simple_map_init(&subdev->map);
+
+	/*
+	 * Now let's probe for the actual flash.  Do it here since
+	 * specific machine settings might have been set above.
+	 */
+	subdev->mtd = do_map_probe(pdata->map_name, &subdev->map);
+	if (subdev->mtd == NULL) {
+		ret = -ENXIO;
+		goto err;
+	}
+	subdev->mtd->owner = THIS_MODULE;
+
+	dev_info(&subdev->pdev->dev, "CFI device at 0x%08lx, %dMiB, "
+	         "%d-bit\n", phys, subdev->mtd->size >> 20,
+	         subdev->map.bankwidth * 8);
+
+	return 0;
+
+err:
+	physmapcc_destroy_subdev(subdev);
+out:
+	return ret;
+}
+
+static void physmapcc_destroy(struct physmapcc_drvdata *drvdata,
+                              struct physmapcc_platform_data *pdata)
+{
+	int i;
+
+	if (drvdata->mtd) {
+		if (drvdata->nr_parts == 0)
+			del_mtd_device(drvdata->mtd);
+#ifdef CONFIG_MTD_PARTITIONS
+		else
+			del_mtd_partitions(drvdata->mtd);
+#endif
+#ifdef CONFIG_MTD_CONCAT
+		if (drvdata->mtd != drvdata->subdev[0].mtd)
+			mtd_concat_destroy(drvdata->mtd);
+#endif
+	}
+
+	kfree(drvdata->parts);
+
+	for (i = drvdata->num_subdev - 1; i >= 0; i--)
+		physmapcc_destroy_subdev(&drvdata->subdev[i]);
+	kfree(drvdata);
+
+	if (pdata->exit)
+		pdata->exit();
+
+	return;
+}
+
+static struct physmapcc_drvdata *__init physmapcc_setup_mtd(
+           struct platform_device *pdev, struct physmapcc_platform_data *pdata)
+{
+	struct physmapcc_drvdata *drvdata;
+	int nr, size, i, ret = 0;
+
+	/*
+	 * Count number of devices.
+	 */
+	for (nr = 0; ; nr++)
+		if (!platform_get_resource(pdev, IORESOURCE_MEM, nr))
+			break;
+
+	if (nr == 0) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	size = sizeof(*drvdata) + sizeof(struct physmapcc_subdev) * nr;
+
+	/*
+	 * Allocate the map_info structs in one go.
+	 */
+	drvdata = kzalloc(size, GFP_KERNEL);
+	if (!drvdata) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	if (pdata->init) {
+		ret = pdata->init();
+		if (ret)
+			goto err;
+	}
+
+	/*
+	 * Claim and then map the memory regions.
+	 */
+	for (i = 0; i < nr; i++) {
+		struct physmapcc_subdev *subdev = &drvdata->subdev[i];
+		struct resource *res;
+
+		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+		if (!res)
+			break;
+
+		subdev->map.name = subdev->name;
+		sprintf(subdev->name, "%s-%d", pdata->name, i);
+		subdev->pdev = pdev;
+
+		ret = physmapcc_probe_subdev(subdev, res);
+		if (ret)
+			break;
+	}
+
+	drvdata->num_subdev = i;
+
+	/*
+	 * ENXIO is special.  It means we didn't find a chip when we probed.
+	 */
+	if (ret != 0 && !(ret == -ENXIO && drvdata->num_subdev > 0))
+		goto err;
+
+	/*
+	 * If we found one device, don't bother with concat support.  If
+	 * we found multiple devices, use concat if we have it available,
+	 * otherwise fail.  Either way, it'll be called "physmapcc".
+	 */
+	if (drvdata->num_subdev == 1) {
+		strcpy(drvdata->subdev[0].name, pdata->name);
+		drvdata->mtd = drvdata->subdev[0].mtd;
+		ret = 0;
+	} else if (drvdata->num_subdev > 1) {
+#ifdef CONFIG_MTD_CONCAT
+		struct mtd_info *cdev[nr];
+		/*
+		 * We detected multiple devices.  Concatenate them together.
+		 */
+		for (i = 0; i < drvdata->num_subdev; i++)
+			cdev[i] = drvdata->subdev[i].mtd;
+
+		drvdata->mtd = mtd_concat_create(cdev, drvdata->num_subdev,
+		                                 pdata->name);
+		if (drvdata->mtd == NULL)
+			ret = -ENXIO;
+#else
+		dev_err(&pdev->dev, "multiple devices found but MTD concat "
+		        "support disabled.\n");
+		ret = -ENXIO;
+#endif
+	}
+
+	if (ret == 0)
+		return drvdata;
+
+err:
+	physmapcc_destroy(drvdata, pdata);
+out:
+	return ERR_PTR(ret);
+}
+
+static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
+
+static int __init physmapcc_probe(struct platform_device *pdev)
+{
+	struct physmapcc_platform_data *pdata = pdev->dev.platform_data;
+	struct mtd_partition *parts;
+	const char *part_type = NULL;
+	struct physmapcc_drvdata *drvdata;
+	int err, nr_parts = 0;
+
+	if (!pdata)
+		return -ENODEV;
+
+	drvdata = physmapcc_setup_mtd(pdev, pdata);
+	if (IS_ERR(drvdata)) {
+		err = PTR_ERR(drvdata);
+		goto out;
+	}
+
+	/*
+	 * Partition selection stuff.
+	 */
+#ifdef CONFIG_MTD_PARTITIONS
+	nr_parts = parse_mtd_partitions(drvdata->mtd, part_probes, &parts, 0);
+	if (nr_parts > 0) {
+		drvdata->parts = parts;
+		part_type = "dynamic";
+	} else
+#endif
+	{
+		parts = pdata->parts;
+		nr_parts = pdata->nr_parts;
+		part_type = "static";
+	}
+
+	if (nr_parts == 0) {
+		dev_notice(&pdev->dev, "no partition info available, "
+		           "registering whole flash\n");
+		add_mtd_device(drvdata->mtd);
+	} else {
+		dev_notice(&pdev->dev, "using %s partition definition\n",
+		           part_type);
+		add_mtd_partitions(drvdata->mtd, parts, nr_parts);
+	}
+
+	drvdata->nr_parts = nr_parts;
+
+	platform_set_drvdata(pdev, drvdata);
+	err = 0;
+
+out:
+	return err;
+}
+
+static int __exit physmapcc_remove(struct platform_device *pdev)
+{
+	struct physmapcc_drvdata *drvdata = platform_get_drvdata(pdev);
+	struct physmapcc_platform_data *pdata = pdev->dev.platform_data;
+
+	physmapcc_destroy(drvdata, pdata);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int physmapcc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct physmapcc_drvdata *drvdata = platform_get_drvdata(pdev);
+	int ret = 0;
+
+	if (drvdata)
+		ret = drvdata->mtd->suspend(drvdata->mtd);
+
+	return ret;
+}
+
+static int physmapcc_resume(struct platform_device *pdev)
+{
+	struct physmapcc_drvdata *drvdata = platform_get_drvdata(pdev);
+
+	if (drvdata)
+		drvdata->mtd->resume(drvdata->mtd);
+
+	return 0;
+}
+
+static void physmapcc_shutdown(struct platform_device *pdev)
+{
+	struct physmapcc_drvdata *drvdata = platform_get_drvdata(pdev);
+
+	if (drvdata && drvdata->mtd->suspend(drvdata->mtd) == 0)
+		drvdata->mtd->resume(drvdata->mtd);
+
+	return;
+}
+#else
+#define physmapcc_suspend NULL
+#define physmapcc_resume NULL
+#define physmapcc_shutdown NULL
+#endif
+
+static struct platform_driver physmapcc_driver = {
+	.driver = {
+		.name = "physmap-concat",
+	},
+	.probe = physmapcc_probe,
+	.remove = __exit_p(physmapcc_remove),
+	.suspend = physmapcc_suspend,
+	.resume = physmapcc_resume,
+	.shutdown = physmapcc_shutdown,
+};
+
+static int __init physmapcc_init(void)
+{
+	return platform_driver_register(&physmapcc_driver);
+}
+
+static void __exit physmapcc_exit(void)
+{
+	platform_driver_unregister(&physmapcc_driver);
+
+	return;
+}
+
+module_init(physmapcc_init);
+module_exit(physmapcc_exit);
+
+MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>, Anton Vorontsov <cbou@mail.ru>");
+MODULE_DESCRIPTION("Generic configurable MTD map driver with concat support");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mtd/physmapcc.h b/include/linux/mtd/physmapcc.h
new file mode 100644
index 0000000..66e8f09
--- /dev/null
+++ b/include/linux/mtd/physmapcc.h
@@ -0,0 +1,39 @@
+/*
+ * Generic configurable MTD map driver with concat support
+ *
+ * Based on sa1100-flash driver
+ *
+ * Copyright (c) 2007 Anton Vorontsov <cbou@mail.ru>
+ * Copyright (c) 2003 Russell King, All Rights Reserved.
+ * Copyright (c) 2000 Nicolas Pitre <nico@cam.org>
+ *
+ * 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 MTD_PHYSMAPCC_H
+#define MTD_PHYSMAPCC_H
+
+struct mtd_partition;
+
+/*
+ * map_name:  the map probe function name
+ * name:      flash device name (eg, as used with mtdparts=)
+ * init:      method called at driver/device initialisation
+ * exit:      method called at driver/device removal
+ * set_vpp:   method called to enable or disable VPP
+ * parts:     optional array of mtd_partitions for static partitioning
+ * nr_parts:  number of mtd_partitions for static partitoning
+ */
+struct physmapcc_platform_data {
+	const char *map_name;
+	const char *name;
+	int (*init)(void);
+	void (*exit)(void);
+	void (*set_vpp)(int on);
+	struct mtd_partition *parts;
+	unsigned int nr_parts;
+};
+
+#endif /* MTD_PHYSMAPCC_H */
-- 
1.5.1.1-dirty

Re: [PATCH] physmap-concat map platform driver

[Lennert Buytenhek]

On Sat, May 26, 2007 at 04:29:25AM +0400, Anton Vorontsov wrote:

> This is physmap-concat driver, which is plain sa1100-flash.c
> with factored out arch-specific code. This driver is essential for
> boards using multiple nonindentical chips on the board.

Doesn't physmap also support multiple nonidentical chips?

What physmap doesn't support is multiple discontiguous memory
regions.  Maybe it makes more sense to add that support to physmap
instead?

Re: [PATCH] physmap-concat map platform driver

[Anton Vorontsov]

On Thu, May 31, 2007 at 11:27:49PM +0200, Lennert Buytenhek wrote:
> On Sat, May 26, 2007 at 04:29:25AM +0400, Anton Vorontsov wrote:
> 
> > This is physmap-concat driver, which is plain sa1100-flash.c
> > with factored out arch-specific code. This driver is essential for
> > boards using multiple nonindentical chips on the board.
> 
> Doesn't physmap also support multiple nonidentical chips?

Nope. E.g. if I have two chips, 32M + 16M, second chip will be visible
as 32M, which is wrong. As "workaround" I can register two physmap
devices for each chip. But then I can't concat them, i.e. use two
chips for one partition.

> What physmap doesn't support is multiple discontiguous memory
> regions.

Yes, this is another disadvantage of current physmap.

> Maybe it makes more sense to add that support to physmap
> instead?

Well.. more easier solution would be merging physmap-concat to physmap,
trying make physmap-concat platform_data-compatible.

I can try implement that.

Thanks,

-- 
Anton Vorontsov
email: cbou@mail.ru
backup email: ya-cbou@yandex.ru
irc://irc.freenode.org/bd2

Re: [PATCH] physmap-concat map platform driver

[Lennert Buytenhek]

On Fri, Jun 01, 2007 at 01:58:38AM +0400, Anton Vorontsov wrote:

> > > This is physmap-concat driver, which is plain sa1100-flash.c
> > > with factored out arch-specific code. This driver is essential for
> > > boards using multiple nonindentical chips on the board.
> > 
> > Doesn't physmap also support multiple nonidentical chips?
> 
> Nope. E.g. if I have two chips, 32M + 16M, second chip will be visible
> as 32M, which is wrong.

OK, why is that?  Is that easily fixable?


> > What physmap doesn't support is multiple discontiguous memory
> > regions.
> 
> Yes, this is another disadvantage of current physmap.
> 
> > Maybe it makes more sense to add that support to physmap
> > instead?
> 
> Well.. more easier solution would be merging physmap-concat to physmap,
> trying make physmap-concat platform_data-compatible.

Hmmm, isn't that more or less what I said?  What's the difference?


thanks,
Lennert

Re: [PATCH] physmap-concat map platform driver

[Anton Vorontsov]

On Thu, Jun 07, 2007 at 02:07:51PM +0200, Lennert Buytenhek wrote:
> On Fri, Jun 01, 2007 at 01:58:38AM +0400, Anton Vorontsov wrote:
> 
> > > > This is physmap-concat driver, which is plain sa1100-flash.c
> > > > with factored out arch-specific code. This driver is essential for
> > > > boards using multiple nonindentical chips on the board.
> > > 
> > > Doesn't physmap also support multiple nonidentical chips?
> > 
> > Nope. E.g. if I have two chips, 32M + 16M, second chip will be visible
> > as 32M, which is wrong.
> 
> OK, why is that?  Is that easily fixable?

Don't know why, David said it's what expected in such setup, and that's
indeed what I'm observing. I'm unsure that it needs any fixups though.
For now I'm just registering two physmap devices, per each chip.

> > > What physmap doesn't support is multiple discontiguous memory
> > > regions.
> > 
> > Yes, this is another disadvantage of current physmap.
> > 
> > > Maybe it makes more sense to add that support to physmap
> > > instead?
> > 
> > Well.. more easier solution would be merging physmap-concat to physmap,
> > trying make physmap-concat platform_data-compatible.
> 
> Hmmm, isn't that more or less what I said?  What's the difference?

That's exactly what you've said. I was in hurry and misread your
initial message. Sorry.

> thanks,
> Lennert

Thanks,

-- 
Anton Vorontsov
email: cbou@mail.ru
backup email: ya-cbou@yandex.ru
irc://irc.freenode.org/bd2

Re: [PATCH] physmap-concat map platform driver

[Stefan Roese]

Hi Anton,

On Thursday 31 May 2007, Anton Vorontsov wrote:
> > Maybe it makes more sense to add that support to physmap
> > instead?
>
> Well.. more easier solution would be merging physmap-concat to physmap,
> trying make physmap-concat platform_data-compatible.
>
> I can try implement that.

Did you make any progress here? Just checking, since I have the same problem 
supporting the Intel 48F4400 which consists of two non-identical NOR chips 
with different geometries. If you don't have anything yet, I'll come up with 
a patch to extend the physmap driver to support multiple regions.

Thanks.

Best regards,
Stefan

Re: [PATCH] physmap-concat map platform driver

[Anton Vorontsov]

On Fri, Feb 01, 2008 at 02:05:05PM +0100, Stefan Roese wrote:
> Hi Anton,
> 
> On Thursday 31 May 2007, Anton Vorontsov wrote:
> > > Maybe it makes more sense to add that support to physmap
> > > instead?
> >
> > Well.. more easier solution would be merging physmap-concat to physmap,
> > trying make physmap-concat platform_data-compatible.
> >
> > I can try implement that.
> 
> Did you make any progress here?

Nope, sorry. I needed this for some ARM machine, but recently had no
time to work on it.

> Just checking, since I have the same problem 
> supporting the Intel 48F4400 which consists of two non-identical NOR chips 
> with different geometries. If you don't have anything yet, I'll come up with 
> a patch to extend the physmap driver to support multiple regions.

That would be great.


Thanks,

p.s. removing kernel-disscuss@handhelds.org from Cc: since it's dead
for months for unknown reason.

-- 
Anton Vorontsov
email: cbou@mail.ru
backup email: ya-cbou@yandex.ru
irc://irc.freenode.net/bd2