/* * 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_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 __devinit 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 = kzalloc(sizeof(struct socrates_nand_host), GFP_KERNEL); if (!host) { printk(KERN_ERR "socrates_nand: failed to allocate device structure.\n"); return -ENOMEM; } host->io_base = of_iomap(ofdev->dev.of_node, 0); if (host->io_base == NULL) { printk(KERN_ERR "socrates_nand: ioremap failed\n"); kfree(host); 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: dev_set_drvdata(&ofdev->dev, NULL); iounmap(host->io_base); kfree(host); return res; } /* * Remove a NAND device. */ static int __devexit 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); dev_set_drvdata(&ofdev->dev, NULL); iounmap(host->io_base); kfree(host); 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", .owner = THIS_MODULE, .of_match_table = socrates_nand_match, }, .probe = socrates_nand_probe, .remove = __devexit_p(socrates_nand_remove), }; module_platform_driver(socrates_nand_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Ilya Yanok"); MODULE_DESCRIPTION("NAND driver for Socrates board");