mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Cyril Bur](/assets/img/avatar_default.png)
Powerpc powernv platforms allow access to certain system flash devices through a firmwarwe interface. This change adds an mtd driver for these flash devices. Minor updates from Jeremy Kerr and Joel Stanley. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Reviewed-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
285 lines
6.6 KiB
C
285 lines
6.6 KiB
C
/*
|
|
* OPAL PNOR flash MTD abstraction
|
|
*
|
|
* Copyright IBM 2015
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#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,
|
|
};
|
|
|
|
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");
|
|
|
|
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:
|
|
BUG_ON(1);
|
|
}
|
|
|
|
if (rc != OPAL_ASYNC_COMPLETION) {
|
|
dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n",
|
|
op, rc);
|
|
opal_async_release_token(token);
|
|
return -EIO;
|
|
}
|
|
|
|
rc = opal_async_wait_response(token, &msg);
|
|
opal_async_release_token(token);
|
|
if (rc) {
|
|
dev_err(dev, "opal async wait failed (rc %d)\n", rc);
|
|
return -EIO;
|
|
}
|
|
|
|
rc = be64_to_cpu(msg.params[1]);
|
|
if (rc == OPAL_SUCCESS) {
|
|
rc = 0;
|
|
if (retlen)
|
|
*retlen = len;
|
|
} else {
|
|
rc = -EIO;
|
|
}
|
|
|
|
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;
|
|
|
|
erase->state = MTD_ERASING;
|
|
|
|
/* todo: register our own notifier to do a true async implementation */
|
|
rc = powernv_flash_async_op(mtd, FLASH_OP_ERASE, erase->addr,
|
|
erase->len, NULL, NULL);
|
|
|
|
if (rc) {
|
|
erase->fail_addr = erase->addr;
|
|
erase->state = MTD_ERASE_FAILED;
|
|
} else {
|
|
erase->state = MTD_ERASE_DONE;
|
|
}
|
|
mtd_erase_callback(erase);
|
|
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 = of_get_property(dev->of_node, "name", NULL);
|
|
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;
|
|
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) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
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");
|
|
goto out;
|
|
}
|
|
|
|
ret = powernv_flash_set_driver_info(dev, &data->mtd);
|
|
if (ret)
|
|
goto out;
|
|
|
|
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
|
|
*/
|
|
ret = mtd_device_register(&data->mtd, NULL, 0);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* 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");
|