Re: [RFC PATCH] mtd: maps: Get rid of the latch-addr-flash driver

[Vignesh R <vigneshr@ti.com>]

+ Sekhar, who is DaVinci port maintainer

On 05-Oct-18 4:11 AM, Boris Brezillon wrote:
> Looks like this driver was initially added to support the NOR on the
> DA830-EVM (Davinci) board, but the board file update was never merged.
> 
> Keeping unused drivers just adds to the maintenance burden, so let's
> remove it if nobody uses it.
> 
> Cc: David Griego <dgriego@mvista.com>
> Cc: Aleksey Makarov <amakarov@ru.mvista.com>
> Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
> Cc: Savinay Dharmappa <savinay.dharmappa@ti.com>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> ---
> Hi,
> 
> If anyone cares about this driver, please raise your voice. If I have no
> news before the 4.21 (5.1?) merge window, I'll merge the patch.
> 
> Regards,
> 
> Boris
> ---
>  drivers/mtd/maps/Kconfig            |   9 --
>  drivers/mtd/maps/Makefile           |   1 -
>  drivers/mtd/maps/latch-addr-flash.c | 229 ------------------------------------
>  3 files changed, 239 deletions(-)
>  delete mode 100644 drivers/mtd/maps/latch-addr-flash.c
> 
> diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
> index 4fd13d76b7b5..85ac3d1359aa 100644
> --- a/drivers/mtd/maps/Kconfig
> +++ b/drivers/mtd/maps/Kconfig
> @@ -399,13 +399,4 @@ config MTD_PISMO
>  
>  	  When built as a module, it will be called pismo.ko
>  
> -config MTD_LATCH_ADDR
> -	tristate "Latch-assisted Flash Chip Support"
> -	depends on MTD_COMPLEX_MAPPINGS
> -	help
> -	  Map driver which allows flashes to be partially physically addressed
> -	  and have the upper address lines set by a board specific code.
> -
> -	  If compiled as a module, it will be called latch-addr-flash.
> -
>  endmenu
> diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
> index acec0fbfa18d..f243d2a5edc5 100644
> --- a/drivers/mtd/maps/Makefile
> +++ b/drivers/mtd/maps/Makefile
> @@ -43,5 +43,4 @@ obj-$(CONFIG_MTD_PLATRAM)	+= plat-ram.o
>  obj-$(CONFIG_MTD_INTEL_VR_NOR)	+= intel_vr_nor.o
>  obj-$(CONFIG_MTD_RBTX4939)	+= rbtx4939-flash.o
>  obj-$(CONFIG_MTD_VMU)		+= vmu-flash.o
> -obj-$(CONFIG_MTD_LATCH_ADDR)	+= latch-addr-flash.o
>  obj-$(CONFIG_MTD_LANTIQ)	+= lantiq-flash.o
> diff --git a/drivers/mtd/maps/latch-addr-flash.c b/drivers/mtd/maps/latch-addr-flash.c
> deleted file mode 100644
> index 51db24b7f88d..000000000000
> --- a/drivers/mtd/maps/latch-addr-flash.c
> +++ /dev/null
> @@ -1,229 +0,0 @@
> -/*
> - * Interface for NOR flash driver whose high address lines are latched
> - *
> - * Copyright © 2000 Nicolas Pitre <nico@cam.org>
> - * Copyright © 2005-2008 Analog Devices Inc.
> - * Copyright © 2008 MontaVista Software, Inc. <source@mvista.com>
> - *
> - * This file is licensed under the terms of the GNU General Public License
> - * version 2. This program is licensed "as is" without any warranty of any
> - * kind, whether express or implied.
> - */
> -
> -#include <linux/kernel.h>
> -#include <linux/module.h>
> -#include <linux/mtd/mtd.h>
> -#include <linux/mtd/map.h>
> -#include <linux/mtd/partitions.h>
> -#include <linux/platform_device.h>
> -#include <linux/mtd/latch-addr-flash.h>
> -#include <linux/slab.h>
> -
> -#define DRIVER_NAME "latch-addr-flash"
> -
> -struct latch_addr_flash_info {
> -	struct mtd_info		*mtd;
> -	struct map_info		map;
> -	struct resource		*res;
> -
> -	void			(*set_window)(unsigned long offset, void *data);
> -	void			*data;
> -
> -	/* cache; could be found out of res */
> -	unsigned long		win_mask;
> -
> -	spinlock_t		lock;
> -};
> -
> -static map_word lf_read(struct map_info *map, unsigned long ofs)
> -{
> -	struct latch_addr_flash_info *info;
> -	map_word datum;
> -
> -	info = (struct latch_addr_flash_info *)map->map_priv_1;
> -
> -	spin_lock(&info->lock);
> -
> -	info->set_window(ofs, info->data);
> -	datum = inline_map_read(map, info->win_mask & ofs);
> -
> -	spin_unlock(&info->lock);
> -
> -	return datum;
> -}
> -
> -static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)
> -{
> -	struct latch_addr_flash_info *info;
> -
> -	info = (struct latch_addr_flash_info *)map->map_priv_1;
> -
> -	spin_lock(&info->lock);
> -
> -	info->set_window(ofs, info->data);
> -	inline_map_write(map, datum, info->win_mask & ofs);
> -
> -	spin_unlock(&info->lock);
> -}
> -
> -static void lf_copy_from(struct map_info *map, void *to,
> -		unsigned long from, ssize_t len)
> -{
> -	struct latch_addr_flash_info *info =
> -		(struct latch_addr_flash_info *) map->map_priv_1;
> -	unsigned n;
> -
> -	while (len > 0) {
> -		n = info->win_mask + 1 - (from & info->win_mask);
> -		if (n > len)
> -			n = len;
> -
> -		spin_lock(&info->lock);
> -
> -		info->set_window(from, info->data);
> -		memcpy_fromio(to, map->virt + (from & info->win_mask), n);
> -
> -		spin_unlock(&info->lock);
> -
> -		to += n;
> -		from += n;
> -		len -= n;
> -	}
> -}
> -
> -static char *rom_probe_types[] = { "cfi_probe", NULL };
> -
> -static int latch_addr_flash_remove(struct platform_device *dev)
> -{
> -	struct latch_addr_flash_info *info;
> -	struct latch_addr_flash_data *latch_addr_data;
> -
> -	info = platform_get_drvdata(dev);
> -	if (info == NULL)
> -		return 0;
> -
> -	latch_addr_data = dev_get_platdata(&dev->dev);
> -
> -	if (info->mtd != NULL) {
> -		mtd_device_unregister(info->mtd);
> -		map_destroy(info->mtd);
> -	}
> -
> -	if (info->map.virt != NULL)
> -		iounmap(info->map.virt);
> -
> -	if (info->res != NULL)
> -		release_mem_region(info->res->start, resource_size(info->res));
> -
> -	kfree(info);
> -
> -	if (latch_addr_data->done)
> -		latch_addr_data->done(latch_addr_data->data);
> -
> -	return 0;
> -}
> -
> -static int latch_addr_flash_probe(struct platform_device *dev)
> -{
> -	struct latch_addr_flash_data *latch_addr_data;
> -	struct latch_addr_flash_info *info;
> -	resource_size_t win_base = dev->resource->start;
> -	resource_size_t win_size = resource_size(dev->resource);
> -	char **probe_type;
> -	int chipsel;
> -	int err;
> -
> -	latch_addr_data = dev_get_platdata(&dev->dev);
> -	if (latch_addr_data == NULL)
> -		return -ENODEV;
> -
> -	pr_notice("latch-addr platform flash device: %#llx byte "
> -		  "window at %#.8llx\n",
> -		  (unsigned long long)win_size, (unsigned long long)win_base);
> -
> -	chipsel = dev->id;
> -
> -	if (latch_addr_data->init) {
> -		err = latch_addr_data->init(latch_addr_data->data, chipsel);
> -		if (err != 0)
> -			return err;
> -	}
> -
> -	info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
> -	if (info == NULL) {
> -		err = -ENOMEM;
> -		goto done;
> -	}
> -
> -	platform_set_drvdata(dev, info);
> -
> -	info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
> -	if (info->res == NULL) {
> -		dev_err(&dev->dev, "Could not reserve memory region\n");
> -		err = -EBUSY;
> -		goto free_info;
> -	}
> -
> -	info->map.name		= DRIVER_NAME;
> -	info->map.size		= latch_addr_data->size;
> -	info->map.bankwidth	= latch_addr_data->width;
> -
> -	info->map.phys		= NO_XIP;
> -	info->map.virt		= ioremap(win_base, win_size);
> -	if (!info->map.virt) {
> -		err = -ENOMEM;
> -		goto free_res;
> -	}
> -
> -	info->map.map_priv_1	= (unsigned long)info;
> -
> -	info->map.read		= lf_read;
> -	info->map.copy_from	= lf_copy_from;
> -	info->map.write		= lf_write;
> -	info->set_window	= latch_addr_data->set_window;
> -	info->data		= latch_addr_data->data;
> -	info->win_mask		= win_size - 1;
> -
> -	spin_lock_init(&info->lock);
> -
> -	for (probe_type = rom_probe_types; !info->mtd && *probe_type;
> -		probe_type++)
> -		info->mtd = do_map_probe(*probe_type, &info->map);
> -
> -	if (info->mtd == NULL) {
> -		dev_err(&dev->dev, "map_probe failed\n");
> -		err = -ENODEV;
> -		goto iounmap;
> -	}
> -	info->mtd->dev.parent = &dev->dev;
> -
> -	mtd_device_register(info->mtd, latch_addr_data->parts,
> -			    latch_addr_data->nr_parts);
> -	return 0;
> -
> -iounmap:
> -	iounmap(info->map.virt);
> -free_res:
> -	release_mem_region(info->res->start, resource_size(info->res));
> -free_info:
> -	kfree(info);
> -done:
> -	if (latch_addr_data->done)
> -		latch_addr_data->done(latch_addr_data->data);
> -	return err;
> -}
> -
> -static struct platform_driver latch_addr_flash_driver = {
> -	.probe		= latch_addr_flash_probe,
> -	.remove		= latch_addr_flash_remove,
> -	.driver		= {
> -		.name	= DRIVER_NAME,
> -	},
> -};
> -
> -module_platform_driver(latch_addr_flash_driver);
> -
> -MODULE_AUTHOR("David Griego <dgriego@mvista.com>");
> -MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
> -		"address lines being set board specifically");
> -MODULE_LICENSE("GPL v2");
>