From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 2CA801A072A for ; Wed, 1 Apr 2015 17:05:36 +1100 (AEDT) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Subject: [PATCH 2/2] drivers/mtd: add powernv flash MTD abstraction driver Message-Id: <1427868330.742447.571120567721.2.gpush@pablo> In-Reply-To: <1427868330.741478.119647151764.0.gpush@pablo> To: linux-mtd@lists.infradead.org, linuxppc-dev@lists.ozlabs.org From: Jeremy Kerr Date: Wed, 01 Apr 2015 14:05:30 +0800 Cc: Cyril Bur , Joel Stanley List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Cyril Bur 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 Signed-off-by: Joel Stanley Signed-off-by: Jeremy Kerr --- drivers/mtd/devices/Kconfig | 6 drivers/mtd/devices/Makefile | 1 drivers/mtd/devices/powernv_flash.c | 288 ++++++++++++++++++++++++++++ 3 files changed, 295 insertions(+) diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig index c49d0b1..5065e7c 100644 --- a/drivers/mtd/devices/Kconfig +++ b/drivers/mtd/devices/Kconfig @@ -195,6 +195,12 @@ config MTD_BLOCK2MTD Testing MTD users (eg JFFS2) on large media and media that might be removed during a write (using the floppy drive). +config MTD_POWERNV_FLASH + tristate "powernv flash MTD driver" + depends on PPC_POWERNV + help + This provides an MTD device for flash on powernv OPAL platforms + comment "Disk-On-Chip Device Drivers" config MTD_DOCG3 diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile index f0b0e61..7912d3a 100644 --- a/drivers/mtd/devices/Makefile +++ b/drivers/mtd/devices/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_MTD_SPEAR_SMI) += spear_smi.o obj-$(CONFIG_MTD_SST25L) += sst25l.o obj-$(CONFIG_MTD_BCM47XXSFLASH) += bcm47xxsflash.o obj-$(CONFIG_MTD_ST_SPI_FSM) += st_spi_fsm.o +obj-$(CONFIG_MTD_POWERNV_FLASH) += powernv_flash.o CFLAGS_docg3.o += -I$(src) diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c new file mode 100644 index 0000000..18f8a19 --- /dev/null +++ b/drivers/mtd/devices/powernv_flash.c @@ -0,0 +1,288 @@ +/* + * OPAL PNOR flash MTD abstraction + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include + + +/* + * This driver creates the a Linux MTD abstraction for platform PNOR flash + * backed by OPAL calls + */ + +struct powernv_flash { + struct mtd_info mtd; + uint64_t 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) { + dev_err(dev, "Failed to get an async token\n"); + return -ENOMEM; + } + + 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); + 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 0; +} + +/** + * @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 occured + */ +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 occured + */ +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 0; +} + +/** + * powernv_flash_set_driver_info - Fill the mtd_info structure and docg3 + * structure @pdev: The platform device + * @mtd: The structure to fill + */ +static int __init powernv_flash_set_driver_info(struct device *dev, + struct mtd_info *mtd) +{ + const __be32 *reg, *erase_size; + int count; + + erase_size = of_get_property(dev->of_node, + "ibm,flash-block-size", NULL); + if (!erase_size) { + dev_err(dev, "no device property 'ibm,flash-block-size'\n"); + return 1; + } + + reg = of_get_property(dev->of_node, "reg", &count); + if (count / sizeof(__be32) != 2) { + dev_err(dev, "couldn't get resource information count=%d\n", + count); + return 1; + } + + /* 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_NANDFLASH; + mtd->flags = MTD_CAP_NANDFLASH; + mtd->size = of_read_number(reg, 2); + mtd->erasesize = of_read_number(erase_size, 1); + 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 __init powernv_flash_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct powernv_flash *data; + const __be32 *prop; + int ret; + + ret = -ENOMEM; + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) { + dev_err(dev, "couldn't allocate memory\n"); + goto out; + } + data->mtd.priv = data; + + ret = -EIO; + prop = of_get_property(dev->of_node, "ibm,opal-id", NULL); + if (!prop) { + dev_err(dev, "no device property 'ibm,opal-id\n"); + goto out; + } + data->id = of_read_number(prop, 1); + + if (powernv_flash_set_driver_info(dev, &data->mtd)) + goto out; + + /* + * Skiboot does expose the partitioning information via OF and the + * ofpart parser could partition it all nicely. + * + * 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_parse_register(&data->mtd, NULL , NULL, NULL, 0); + +out: + return ret; +} + +/** + * op_release - Release the driver + * @pdev: the platform device + * + * Returns 0 + */ +static int __exit powernv_flash_release(struct platform_device *pdev) +{ + /* All resources should be freed automatically */ + return 0; +} + +static struct of_device_id powernv_flash_match[] = { + { .compatible = "ibm,opal-flash" }, + {} +}; + +static struct platform_driver powernv_flash_driver = { + .driver = { + .name = "powernv_flash", + .owner = THIS_MODULE, + .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 "); +MODULE_DESCRIPTION("MTD abstraction for OPAL flash");