[PATCH 1/3] drivers: mtd: spinand: Add generic spinand frameowrk and micron driver.
Florian Fainelli
florian at openwrt.org
Wed Jun 26 10:15:56 EDT 2013
Hello,
2013/6/26 Sourav Poddar <sourav.poddar at ti.com>:
> From: Mona Anonuevo <manonuevo at micron.com>
>
> This patch adds support for a generic spinand framework(spinand_mtd.c).
> This frameowrk can be used for other spi based flash devices also. The idea
> is to have a common model under drivers/mtd, as also present for other no spi
> devices(there is a generic framework and device part simply attaches itself to it.)
>
> The generic frework will be used later by me for a SPI based spansion S25FL256 device.
> The patch also contains a micron driver attaching itself to generic framework.
Some general comments below, I do not have any SPI NAND devices, just
reading through the code.
> +
> +config MTD_SPINAND_ONDIEECC
> + bool "Use SPINAND internal ECC"
> + help
> + Internel ECC
> +
> +config MTD_SPINAND_SWECC
> + bool "Use software ECC"
> + depends on MTD_NAND
> + help
> + software ECC
Cannot both of these be somehow detected by the identification bytes?
Or maybe explicitely specified in an identification table?
> +#define mu_spi_nand_driver_version "Beagle-MTD_01.00_Linux2.6.33_20100507"
You probably want to remove this.
> +#define SPI_NAND_MICRON_DRIVER_KEY 0x1233567
Ditto.
> +
> +/****************************************************************************/
> +
> +/**
> + OOB area specification layout: Total 32 available free bytes.
> +*/
> +static struct nand_ecclayout spinand_oob_64 = {
> + .eccbytes = 24,
> + .eccpos = {
> + 1, 2, 3, 4, 5, 6,
> + 17, 18, 19, 20, 21, 22,
> + 33, 34, 35, 36, 37, 38,
> + 49, 50, 51, 52, 53, 54, },
> + .oobavail = 32,
> + .oobfree = {
> + {.offset = 8,
> + .length = 8},
> + {.offset = 24,
> + .length = 8},
> + {.offset = 40,
> + .length = 8},
> + {.offset = 56,
> + .length = 8}, }
> +};
This should probably be per-device, or at best supplied by platform data?
> +/**
> + * spinand_cmd - to process a command to send to the SPI Nand
> + *
> + * Description:
> + * Set up the command buffer to send to the SPI controller.
> + * The command buffer has to initized to 0
> + */
> +int spinand_cmd(struct spi_device *spi, struct spinand_cmd *cmd)
> +{
> + int ret;
> + struct spi_message message;
> + struct spi_transfer x[4];
> + u8 dummy = 0xff;
> +
> + spi_message_init(&message);
> + memset(x, 0, sizeof(x));
> +
> + x[0].len = 1;
> + x[0].tx_buf = &cmd->cmd;
> + spi_message_add_tail(&x[0], &message);
> +
> + if (cmd->n_addr) {
> + x[1].len = cmd->n_addr;
> + x[1].tx_buf = cmd->addr;
> + spi_message_add_tail(&x[1], &message);
> + }
> +
> + if (cmd->n_dummy) {
> + x[2].len = cmd->n_dummy;
> + x[2].tx_buf = &dummy;
> + spi_message_add_tail(&x[2], &message);
> + }
> +
> + if (cmd->n_tx) {
> + x[3].len = cmd->n_tx;
> + x[3].tx_buf = cmd->tx_buf;
> + spi_message_add_tail(&x[3], &message);
> + }
> +
> + if (cmd->n_rx) {
> + x[3].len = cmd->n_rx;
> + x[3].rx_buf = cmd->rx_buf;
> + spi_message_add_tail(&x[3], &message);
> + }
> +
> + ret = spi_sync(spi, &message);
If any kind of locking is implicitely done by the SPI layer, you might
want to add a comment to specify it.
[snip]
> + retval = spinand_cmd(spi_nand, &cmd);
> +
> + if (retval != 0) {
> + dev_err(&spi_nand->dev, "error %d reading id\n",
> + (int) retval);
> + return retval;
> + }
Just:
if (retval)
dev_err(&spi_nand->dev, "...
return retval
[snip]
> + retval = spinand_cmd(spi_nand, &cmd);
> +
> + if (retval != 0) {
> + dev_err(&spi_nand->dev, "error %d lock block\n",
> + (int) retval);
> + return retval;
> + }
Same here
[snip]
> + if (retval != 0) {
> + dev_err(&spi_nand->dev, "error %d reading status register\n",
> + (int) retval);
> + return retval;
> + }
And here
[snip]
> + if (retval != 0) {
> + dev_err(&spi_nand->dev, "error %d get otp\n",
> + (int) retval);
> + return retval;
> + }
And here
[snip]
> + if (retval != 0) {
> + dev_err(&spi_nand->dev, "error %d set otp\n",
> + (int) retval);
> + return retval;
And here
[snip]
> +*/
> +#ifdef CONFIG_MTD_SPINAND_ONDIEECC
Same comment as above, you could probably do not make this enclosed
within an ifdef, but always compile it and test for a device flag for
instance.
> +static int spinand_enable_ecc(struct spi_device *spi_nand,
> + struct spinand_info *info)
> +{
> + ssize_t retval;
> + u8 otp = 0;
> +
> + retval = spinand_get_otp(spi_nand, info, &otp);
> +
> + if ((otp & OTP_ECC_MASK) == OTP_ECC_MASK) {
> + return 0;
> + } else {
> + otp |= OTP_ECC_MASK;
> + retval = spinand_set_otp(spi_nand, info, &otp);
> + retval = spinand_get_otp(spi_nand, info, &otp);
> + return retval;
> + }
You probably do not need the if() else() because the if branch returns
immediately.
[snip]
> + if ((otp & OTP_ECC_MASK) == OTP_ECC_MASK) {
> + otp &= ~OTP_ECC_MASK;
> + retval = spinand_set_otp(spi_nand, info, &otp);
> + retval = spinand_get_otp(spi_nand, info, &otp);
> + return retval;
> + } else {
> + return 0;
Same here
[snip]
> +static int spinand_read_page(struct spi_device *spi_nand,
> + struct spinand_info *info, u16 page_id, u16 offset,
> + u16 len, u8 *rbuf)
> +{
> + ssize_t retval;
> + u8 status = 0;
> +
> + retval = spinand_read_page_to_cache(spi_nand, info, page_id);
Either you check the value and return or you do not.
> +
> + while (1) {
> + retval = spinand_read_status(spi_nand, info, &status);
> + if (retval < 0) {
> + dev_err(&spi_nand->dev, "error %d reading status register\n",
> + (int) retval);
> + return retval;
> + }
> +
> + if ((status & STATUS_OIP_MASK) == STATUS_READY) {
> + if ((status & STATUS_ECC_MASK) == STATUS_ECC_ERROR) {
> + dev_err(&spi_nand->dev,
> + "ecc error, page=%d\n", page_id);
> + }
> + break;
> + }
Should not we somehow call cpu_relax() or wait for some delay here
before issuing multiple READ_STATUS commands?
[snip]
> + retval = spinand_write_enable(spi_nand, info);
> +
> + retval = spinand_program_data_to_cache(spi_nand, info, offset,
> + len, wbuf);
> +
> + retval = spinand_program_execute(spi_nand, info, page_id);
Same here either check return value and return or do not check the
return value at all.
[snip]
> +static int spinand_get_info(struct spi_device *spi_nand,
> + struct spinand_info *info, u8 *id)
> +{
> + if (id[0] == 0x2C && (id[1] == 0x11 ||
> + id[1] == 0x12 || id[1] == 0x13)) {
> + info->mid = id[0];
> + info->did = id[1];
> + info->name = "MT29F1G01ZAC";
> + info->nand_size = (1024 * 64 * 2112);
> + info->usable_size = (1024 * 64 * 2048);
> + info->block_size = (2112*64);
> + info->block_main_size = (2048*64);
> + info->block_num_per_chip = 1024;
> + info->page_size = 2112;
> + info->page_main_size = 2048;
> + info->page_spare_size = 64;
> + info->page_num_per_block = 64;
> +
> + info->block_shift = 17;
> + info->block_mask = 0x1ffff;
> +
> + info->page_shift = 11;
> + info->page_mask = 0x7ff;
> +
> + info->ecclayout = &spinand_oob_64;
> + }
Even if there is just one device supported by this driver, you
definitively want to use an identification table so that people can
easily add new chips without much pain.
> + return 0;
> +}
> +
> +/**
> + * spinand_probe - [spinand Interface]
> + * @spi_nand: registered device driver.
> + *
> + * Description:
> + * To set up the device driver parameters to make the device available.
> +*/
> +static int spinand_probe(struct spi_device *spi_nand)
> +{
> + ssize_t retval;
> + struct mtd_info *mtd;
> + struct spinand_chip *chip;
> + struct spinand_info *info;
> + struct flash_platform_data *data;
> + struct mtd_part_parser_data ppdata;
> + u8 id[2] = {0};
> +
> + retval = spinand_reset(spi_nand);
> + retval = spinand_reset(spi_nand);
> + retval = spinand_read_id(spi_nand, (u8 *)&id);
> + if (id[0] == 0 && id[1] == 0) {
> + pr_info(KERN_INFO "SPINAND: read id error! 0x%02x, 0x%02x!\n",
> + id[0], id[1]);
> + return 0;
> + }
> +
> + data = spi_nand->dev.platform_data;
> + info = kzalloc(sizeof(struct spinand_info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
You can use devm_kzalloc() to get your chunks of memory freed upon
driver removal.
> +
> + retval = spinand_get_info(spi_nand, info, (u8 *)&id);
> + pr_info(KERN_INFO "SPINAND: 0x%02x, 0x%02x, %s\n",
> + id[0], id[1], info->name);
> + pr_info(KERN_INFO "%s\n", mu_spi_nand_driver_version);
> + retval = spinand_lock_block(spi_nand, info, BL_ALL_UNLOCKED);
> +
> +#ifdef CONFIG_MTD_SPINAND_ONDIEECC
> + retval = spinand_enable_ecc(spi_nand, info);
> +#else
> + retval = spinand_disable_ecc(spi_nand, info);
> +#endif
> +
> + ppdata.of_node = spi_nand->dev.of_node;
You could probably go along and define Device Tree bindings for this
driver at the same time, such that they are directly usable once the
driver is merged.
> diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
> new file mode 100644
> index 0000000..3b8802a
> --- /dev/null
> +++ b/include/linux/mtd/spinand.h
> @@ -0,0 +1,155 @@
> +/*
> + * linux/include/linux/mtd/spinand.h
> + * Copyright (c) 2009-2010 Micron Technology, Inc.
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> +
> + * 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.
> +/bin/bash: 4: command not found
?
> + *
> + * based on nand.h
> + */
> +#ifndef __LINUX_MTD_SPI_NAND_H
> +#define __LINUX_MTD_SPI_NAND_H
> +
> +#include <linux/wait.h>
> +#include <linux/spinlock.h>
> +#include <linux/mtd/mtd.h>
> +
> +/* cmd */
> +#define CMD_READ 0x13
> +#define CMD_READ_RDM 0x03
> +#define CMD_PROG_PAGE_CLRCACHE 0x02
> +#define CMD_PROG_PAGE 0x84
> +#define CMD_PROG_PAGE_EXC 0x10
> +#define CMD_ERASE_BLK 0xd8
> +#define CMD_WR_ENABLE 0x06
> +#define CMD_WR_DISABLE 0x04
> +#define CMD_READ_ID 0x9f
> +#define CMD_RESET 0xff
> +#define CMD_READ_REG 0x0f
> +#define CMD_WRITE_REG 0x1f
Please prefix all of them with SPI_NAND_CMD just to be consistent with
what is defined in include/linux/mtd/nand.h?
> +
> +/* feature/ status reg */
> +#define REG_BLOCK_LOCK 0xa0
> +#define REG_OTP 0xb0
> +#define REG_STATUS 0xc0/* timing */
> +
> +/* status */
> +#define STATUS_OIP_MASK 0x01
> +#define STATUS_READY (0 << 0)
> +#define STATUS_BUSY (1 << 0)
> +
> +#define STATUS_E_FAIL_MASK 0x04
> +#define STATUS_E_FAIL (1 << 2)
> +
> +#define STATUS_P_FAIL_MASK 0x08
> +#define STATUS_P_FAIL (1 << 3)
> +
> +#define STATUS_ECC_MASK 0x30
> +#define STATUS_ECC_1BIT_CORRECTED (1 << 4)
> +#define STATUS_ECC_ERROR (2 << 4)
> +#define STATUS_ECC_RESERVED (3 << 4)
> +
> +
> +/*ECC enable defines*/
> +#define OTP_ECC_MASK 0x10
> +#define OTP_ECC_OFF 0
> +#define OTP_ECC_ON 1
> +
> +#define ECC_DISABLED
> +#define ECC_IN_NAND
> +#define ECC_SOFT
> +
> +/* block lock */
> +#define BL_ALL_LOCKED 0x38
> +#define BL_1_2_LOCKED 0x30
> +#define BL_1_4_LOCKED 0x28
> +#define BL_1_8_LOCKED 0x20
> +#define BL_1_16_LOCKED 0x18
> +#define BL_1_32_LOCKED 0x10
> +#define BL_1_64_LOCKED 0x08
> +#define BL_ALL_UNLOCKED 0
> +
> +struct spinand_info {
> + u8 mid;
> + u8 did;
> + char *name;
> + u64 nand_size;
> + u64 usable_size;
> +
> + u32 block_size;
> + u32 block_main_size;
> + /*u32 block_spare_size; */
> + u16 block_num_per_chip;
> + u16 page_size;
> + u16 page_main_size;
> + u16 page_spare_size;
> + u16 page_num_per_block;
> + u8 block_shift;
> + u32 block_mask;
> + u8 page_shift;
> + u16 page_mask;
> +
> + struct nand_ecclayout *ecclayout;
> +};
> +
> +typedef enum {
> + FL_READY,
> + FL_READING,
> + FL_WRITING,
> + FL_ERASING,
> + FL_SYNCING,
> + FL_LOCKING,
> + FL_RESETING,
> + FL_OTPING,
> + FL_PM_SUSPENDED,
> +} spinand_state_t;
Maybe flstate_t from include/linux/mtd/flashchip.h should be made
move/made nore generic such that you can use these defines too?
--
Florian
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