diff options
Diffstat (limited to 'drivers/mtd/nand/socrates_nand.c')
| -rw-r--r-- | drivers/mtd/nand/socrates_nand.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/drivers/mtd/nand/socrates_nand.c b/drivers/mtd/nand/socrates_nand.c new file mode 100644 index 000000000..d71062273 --- /dev/null +++ b/drivers/mtd/nand/socrates_nand.c @@ -0,0 +1,253 @@ +/* + * drivers/mtd/nand/socrates_nand.c + * + * Copyright © 2008 Ilya Yanok, Emcraft Systems + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/nand.h> +#include <linux/mtd/partitions.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/io.h> + +#define FPGA_NAND_CMD_MASK (0x7 << 28) +#define FPGA_NAND_CMD_COMMAND (0x0 << 28) +#define FPGA_NAND_CMD_ADDR (0x1 << 28) +#define FPGA_NAND_CMD_READ (0x2 << 28) +#define FPGA_NAND_CMD_WRITE (0x3 << 28) +#define FPGA_NAND_BUSY (0x1 << 15) +#define FPGA_NAND_ENABLE (0x1 << 31) +#define FPGA_NAND_DATA_SHIFT 16 + +struct socrates_nand_host { + struct nand_chip nand_chip; + struct mtd_info mtd; + void __iomem *io_base; + struct device *dev; +}; + +/** + * socrates_nand_write_buf - write buffer to chip + * @mtd: MTD device structure + * @buf: data buffer + * @len: number of bytes to write + */ +static void socrates_nand_write_buf(struct mtd_info *mtd, + const uint8_t *buf, int len) +{ + int i; + struct nand_chip *this = mtd->priv; + struct socrates_nand_host *host = this->priv; + + for (i = 0; i < len; i++) { + out_be32(host->io_base, FPGA_NAND_ENABLE | + FPGA_NAND_CMD_WRITE | + (buf[i] << FPGA_NAND_DATA_SHIFT)); + } +} + +/** + * socrates_nand_read_buf - read chip data into buffer + * @mtd: MTD device structure + * @buf: buffer to store date + * @len: number of bytes to read + */ +static void socrates_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len) +{ + int i; + struct nand_chip *this = mtd->priv; + struct socrates_nand_host *host = this->priv; + uint32_t val; + + val = FPGA_NAND_ENABLE | FPGA_NAND_CMD_READ; + + out_be32(host->io_base, val); + for (i = 0; i < len; i++) { + buf[i] = (in_be32(host->io_base) >> + FPGA_NAND_DATA_SHIFT) & 0xff; + } +} + +/** + * socrates_nand_read_byte - read one byte from the chip + * @mtd: MTD device structure + */ +static uint8_t socrates_nand_read_byte(struct mtd_info *mtd) +{ + uint8_t byte; + socrates_nand_read_buf(mtd, &byte, sizeof(byte)); + return byte; +} + +/** + * socrates_nand_read_word - read one word from the chip + * @mtd: MTD device structure + */ +static uint16_t socrates_nand_read_word(struct mtd_info *mtd) +{ + uint16_t word; + socrates_nand_read_buf(mtd, (uint8_t *)&word, sizeof(word)); + return word; +} + +/* + * Hardware specific access to control-lines + */ +static void socrates_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, + unsigned int ctrl) +{ + struct nand_chip *nand_chip = mtd->priv; + struct socrates_nand_host *host = nand_chip->priv; + uint32_t val; + + if (cmd == NAND_CMD_NONE) + return; + + if (ctrl & NAND_CLE) + val = FPGA_NAND_CMD_COMMAND; + else + val = FPGA_NAND_CMD_ADDR; + + if (ctrl & NAND_NCE) + val |= FPGA_NAND_ENABLE; + + val |= (cmd & 0xff) << FPGA_NAND_DATA_SHIFT; + + out_be32(host->io_base, val); +} + +/* + * Read the Device Ready pin. + */ +static int socrates_nand_device_ready(struct mtd_info *mtd) +{ + struct nand_chip *nand_chip = mtd->priv; + struct socrates_nand_host *host = nand_chip->priv; + + if (in_be32(host->io_base) & FPGA_NAND_BUSY) + return 0; /* busy */ + return 1; +} + +/* + * Probe for the NAND device. + */ +static int socrates_nand_probe(struct platform_device *ofdev) +{ + struct socrates_nand_host *host; + struct mtd_info *mtd; + struct nand_chip *nand_chip; + int res; + struct mtd_part_parser_data ppdata; + + /* Allocate memory for the device structure (and zero it) */ + host = devm_kzalloc(&ofdev->dev, sizeof(*host), GFP_KERNEL); + if (!host) + return -ENOMEM; + + host->io_base = of_iomap(ofdev->dev.of_node, 0); + if (host->io_base == NULL) { + dev_err(&ofdev->dev, "ioremap failed\n"); + return -EIO; + } + + mtd = &host->mtd; + nand_chip = &host->nand_chip; + host->dev = &ofdev->dev; + + nand_chip->priv = host; /* link the private data structures */ + mtd->priv = nand_chip; + mtd->name = "socrates_nand"; + mtd->owner = THIS_MODULE; + mtd->dev.parent = &ofdev->dev; + ppdata.of_node = ofdev->dev.of_node; + + /*should never be accessed directly */ + nand_chip->IO_ADDR_R = (void *)0xdeadbeef; + nand_chip->IO_ADDR_W = (void *)0xdeadbeef; + + nand_chip->cmd_ctrl = socrates_nand_cmd_ctrl; + nand_chip->read_byte = socrates_nand_read_byte; + nand_chip->read_word = socrates_nand_read_word; + nand_chip->write_buf = socrates_nand_write_buf; + nand_chip->read_buf = socrates_nand_read_buf; + nand_chip->dev_ready = socrates_nand_device_ready; + + nand_chip->ecc.mode = NAND_ECC_SOFT; /* enable ECC */ + + /* TODO: I have no idea what real delay is. */ + nand_chip->chip_delay = 20; /* 20us command delay time */ + + dev_set_drvdata(&ofdev->dev, host); + + /* first scan to find the device and get the page size */ + if (nand_scan_ident(mtd, 1, NULL)) { + res = -ENXIO; + goto out; + } + + /* second phase scan */ + if (nand_scan_tail(mtd)) { + res = -ENXIO; + goto out; + } + + res = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0); + if (!res) + return res; + + nand_release(mtd); + +out: + iounmap(host->io_base); + return res; +} + +/* + * Remove a NAND device. + */ +static int socrates_nand_remove(struct platform_device *ofdev) +{ + struct socrates_nand_host *host = dev_get_drvdata(&ofdev->dev); + struct mtd_info *mtd = &host->mtd; + + nand_release(mtd); + + iounmap(host->io_base); + + return 0; +} + +static const struct of_device_id socrates_nand_match[] = +{ + { + .compatible = "abb,socrates-nand", + }, + {}, +}; + +MODULE_DEVICE_TABLE(of, socrates_nand_match); + +static struct platform_driver socrates_nand_driver = { + .driver = { + .name = "socrates_nand", + .of_match_table = socrates_nand_match, + }, + .probe = socrates_nand_probe, + .remove = socrates_nand_remove, +}; + +module_platform_driver(socrates_nand_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Ilya Yanok"); +MODULE_DESCRIPTION("NAND driver for Socrates board"); |