diff options
Diffstat (limited to 'drivers/mtd/nand/raw/socrates_nand.c')
| -rw-r--r-- | drivers/mtd/nand/raw/socrates_nand.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/socrates_nand.c b/drivers/mtd/nand/raw/socrates_nand.c new file mode 100644 index 000000000..76d50eb9f --- /dev/null +++ b/drivers/mtd/nand/raw/socrates_nand.c @@ -0,0 +1,241 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright © 2008 Ilya Yanok, Emcraft Systems + */ + +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/rawnand.h> +#include <linux/mtd/partitions.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.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_controller controller; + struct nand_chip nand_chip; + void __iomem *io_base; + struct device *dev; +}; + +/** + * socrates_nand_write_buf - write buffer to chip + * @this: NAND chip object + * @buf: data buffer + * @len: number of bytes to write + */ +static void socrates_nand_write_buf(struct nand_chip *this, const uint8_t *buf, + int len) +{ + int i; + struct socrates_nand_host *host = nand_get_controller_data(this); + + 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 + * @this: NAND chip object + * @buf: buffer to store date + * @len: number of bytes to read + */ +static void socrates_nand_read_buf(struct nand_chip *this, uint8_t *buf, + int len) +{ + int i; + struct socrates_nand_host *host = nand_get_controller_data(this); + 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 nand_chip *this) +{ + uint8_t byte; + socrates_nand_read_buf(this, &byte, sizeof(byte)); + return byte; +} + +/* + * Hardware specific access to control-lines + */ +static void socrates_nand_cmd_ctrl(struct nand_chip *nand_chip, int cmd, + unsigned int ctrl) +{ + struct socrates_nand_host *host = nand_get_controller_data(nand_chip); + 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 nand_chip *nand_chip) +{ + struct socrates_nand_host *host = nand_get_controller_data(nand_chip); + + if (in_be32(host->io_base) & FPGA_NAND_BUSY) + return 0; /* busy */ + return 1; +} + +static int socrates_attach_chip(struct nand_chip *chip) +{ + if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT && + chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN) + chip->ecc.algo = NAND_ECC_ALGO_HAMMING; + + return 0; +} + +static const struct nand_controller_ops socrates_ops = { + .attach_chip = socrates_attach_chip, +}; + +/* + * 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; + + /* 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; + } + + nand_chip = &host->nand_chip; + mtd = nand_to_mtd(nand_chip); + host->dev = &ofdev->dev; + + nand_controller_init(&host->controller); + host->controller.ops = &socrates_ops; + nand_chip->controller = &host->controller; + + /* link the private data structures */ + nand_set_controller_data(nand_chip, host); + nand_set_flash_node(nand_chip, ofdev->dev.of_node); + mtd->name = "socrates_nand"; + mtd->dev.parent = &ofdev->dev; + + nand_chip->legacy.cmd_ctrl = socrates_nand_cmd_ctrl; + nand_chip->legacy.read_byte = socrates_nand_read_byte; + nand_chip->legacy.write_buf = socrates_nand_write_buf; + nand_chip->legacy.read_buf = socrates_nand_read_buf; + nand_chip->legacy.dev_ready = socrates_nand_device_ready; + + /* TODO: I have no idea what real delay is. */ + nand_chip->legacy.chip_delay = 20; /* 20us command delay time */ + + /* + * This driver assumes that the default ECC engine should be TYPE_SOFT. + * Set ->engine_type before registering the NAND devices in order to + * provide a driver specific default value. + */ + nand_chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT; + + dev_set_drvdata(&ofdev->dev, host); + + res = nand_scan(nand_chip, 1); + if (res) + goto out; + + res = mtd_device_register(mtd, NULL, 0); + if (!res) + return res; + + nand_cleanup(nand_chip); + +out: + iounmap(host->io_base); + return res; +} + +/* + * Remove a NAND device. + */ +static void socrates_nand_remove(struct platform_device *ofdev) +{ + struct socrates_nand_host *host = dev_get_drvdata(&ofdev->dev); + struct nand_chip *chip = &host->nand_chip; + int ret; + + ret = mtd_device_unregister(nand_to_mtd(chip)); + WARN_ON(ret); + nand_cleanup(chip); + + iounmap(host->io_base); +} + +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_new = socrates_nand_remove, +}; + +module_platform_driver(socrates_nand_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Ilya Yanok"); +MODULE_DESCRIPTION("NAND driver for Socrates board"); |