linux/drivers/mtd/devices/powernv_flash.c
Thomas Gleixner c942fddf87 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

293 lines
7.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* OPAL PNOR flash MTD abstraction
*
* Copyright IBM 2015
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <asm/opal.h>
/*
* This driver creates the a Linux MTD abstraction for platform PNOR flash
* backed by OPAL calls
*/
struct powernv_flash {
struct mtd_info mtd;
u32 id;
};
enum flash_op {
FLASH_OP_READ,
FLASH_OP_WRITE,
FLASH_OP_ERASE,
};
/*
* Don't return -ERESTARTSYS if we can't get a token, the MTD core
* might have split up the call from userspace and called into the
* driver more than once, we'll already have done some amount of work.
*/
static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
loff_t offset, size_t len, size_t *retlen, u_char *buf)
{
struct powernv_flash *info = (struct powernv_flash *)mtd->priv;
struct device *dev = &mtd->dev;
int token;
struct opal_msg msg;
int rc;
dev_dbg(dev, "%s(op=%d, offset=0x%llx, len=%zu)\n",
__func__, op, offset, len);
token = opal_async_get_token_interruptible();
if (token < 0) {
if (token != -ERESTARTSYS)
dev_err(dev, "Failed to get an async token\n");
else
token = -EINTR;
return token;
}
switch (op) {
case FLASH_OP_READ:
rc = opal_flash_read(info->id, offset, __pa(buf), len, token);
break;
case FLASH_OP_WRITE:
rc = opal_flash_write(info->id, offset, __pa(buf), len, token);
break;
case FLASH_OP_ERASE:
rc = opal_flash_erase(info->id, offset, len, token);
break;
default:
WARN_ON_ONCE(1);
opal_async_release_token(token);
return -EIO;
}
if (rc == OPAL_ASYNC_COMPLETION) {
rc = opal_async_wait_response_interruptible(token, &msg);
if (rc) {
/*
* If we return the mtd core will free the
* buffer we've just passed to OPAL but OPAL
* will continue to read or write from that
* memory.
* It may be tempting to ultimately return 0
* if we're doing a read or a write since we
* are going to end up waiting until OPAL is
* done. However, because the MTD core sends
* us the userspace request in chunks, we need
* it to know we've been interrupted.
*/
rc = -EINTR;
if (opal_async_wait_response(token, &msg))
dev_err(dev, "opal_async_wait_response() failed\n");
goto out;
}
rc = opal_get_async_rc(msg);
}
/*
* OPAL does mutual exclusion on the flash, it will return
* OPAL_BUSY.
* During firmware updates by the service processor OPAL may
* be (temporarily) prevented from accessing the flash, in
* this case OPAL will also return OPAL_BUSY.
* Both cases aren't errors exactly but the flash could have
* changed, userspace should be informed.
*/
if (rc != OPAL_SUCCESS && rc != OPAL_BUSY)
dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n",
op, rc);
if (rc == OPAL_SUCCESS && retlen)
*retlen = len;
rc = opal_error_code(rc);
out:
opal_async_release_token(token);
return rc;
}
/**
* @mtd: the device
* @from: the offset to read from
* @len: the number of bytes to read
* @retlen: the number of bytes actually read
* @buf: the filled in buffer
*
* Returns 0 if read successful, or -ERRNO if an error occurred
*/
static int powernv_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
return powernv_flash_async_op(mtd, FLASH_OP_READ, from,
len, retlen, buf);
}
/**
* @mtd: the device
* @to: the offset to write to
* @len: the number of bytes to write
* @retlen: the number of bytes actually written
* @buf: the buffer to get bytes from
*
* Returns 0 if write successful, -ERRNO if error occurred
*/
static int powernv_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
return powernv_flash_async_op(mtd, FLASH_OP_WRITE, to,
len, retlen, (u_char *)buf);
}
/**
* @mtd: the device
* @erase: the erase info
* Returns 0 if erase successful or -ERRNO if an error occurred
*/
static int powernv_flash_erase(struct mtd_info *mtd, struct erase_info *erase)
{
int rc;
rc = powernv_flash_async_op(mtd, FLASH_OP_ERASE, erase->addr,
erase->len, NULL, NULL);
if (rc)
erase->fail_addr = erase->addr;
return rc;
}
/**
* powernv_flash_set_driver_info - Fill the mtd_info structure and docg3
* structure @pdev: The platform device
* @mtd: The structure to fill
*/
static int powernv_flash_set_driver_info(struct device *dev,
struct mtd_info *mtd)
{
u64 size;
u32 erase_size;
int rc;
rc = of_property_read_u32(dev->of_node, "ibm,flash-block-size",
&erase_size);
if (rc) {
dev_err(dev, "couldn't get resource block size information\n");
return rc;
}
rc = of_property_read_u64(dev->of_node, "reg", &size);
if (rc) {
dev_err(dev, "couldn't get resource size information\n");
return rc;
}
/*
* Going to have to check what details I need to set and how to
* get them
*/
mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
mtd->type = MTD_NORFLASH;
mtd->flags = MTD_WRITEABLE;
mtd->size = size;
mtd->erasesize = erase_size;
mtd->writebufsize = mtd->writesize = 1;
mtd->owner = THIS_MODULE;
mtd->_erase = powernv_flash_erase;
mtd->_read = powernv_flash_read;
mtd->_write = powernv_flash_write;
mtd->dev.parent = dev;
mtd_set_of_node(mtd, dev->of_node);
return 0;
}
/**
* powernv_flash_probe
* @pdev: platform device
*
* Returns 0 on success, -ENOMEM, -ENXIO on error
*/
static int powernv_flash_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct powernv_flash *data;
int ret;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->mtd.priv = data;
ret = of_property_read_u32(dev->of_node, "ibm,opal-id", &(data->id));
if (ret) {
dev_err(dev, "no device property 'ibm,opal-id'\n");
return ret;
}
ret = powernv_flash_set_driver_info(dev, &data->mtd);
if (ret)
return ret;
dev_set_drvdata(dev, data);
/*
* The current flash that skiboot exposes is one contiguous flash chip
* with an ffs partition at the start, it should prove easier for users
* to deal with partitions or not as they see fit
*/
return mtd_device_register(&data->mtd, NULL, 0);
}
/**
* op_release - Release the driver
* @pdev: the platform device
*
* Returns 0
*/
static int powernv_flash_release(struct platform_device *pdev)
{
struct powernv_flash *data = dev_get_drvdata(&(pdev->dev));
/* All resources should be freed automatically */
return mtd_device_unregister(&(data->mtd));
}
static const struct of_device_id powernv_flash_match[] = {
{ .compatible = "ibm,opal-flash" },
{}
};
static struct platform_driver powernv_flash_driver = {
.driver = {
.name = "powernv_flash",
.of_match_table = powernv_flash_match,
},
.remove = powernv_flash_release,
.probe = powernv_flash_probe,
};
module_platform_driver(powernv_flash_driver);
MODULE_DEVICE_TABLE(of, powernv_flash_match);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Cyril Bur <cyril.bur@au1.ibm.com>");
MODULE_DESCRIPTION("MTD abstraction for OPAL flash");