--- /dev/null
+/*
+ * 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;
+}
+
+/**
+ * socrates_nand_verify_buf - Verify chip data against buffer
+ * @mtd: MTD device structure
+ * @buf: buffer containing the data to compare
+ * @len: number of bytes to compare
+ */
+static int socrates_nand_verify_buf(struct mtd_info *mtd, const u8 *buf,
+ int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++) {
+ if (buf[i] != socrates_nand_read_byte(mtd))
+ return -EFAULT;
+ }
+ return 0;
+}
+
+/*
+ * 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;
+}
+
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *part_probes[] = { "cmdlinepart", NULL };
+#endif
+
+/*
+ * Probe for the NAND device.
+ */
+static int __devinit socrates_nand_probe(struct of_device *ofdev,
+ const struct of_device_id *ofid)
+{
+ struct socrates_nand_host *host;
+ struct mtd_info *mtd;
+ struct nand_chip *nand_chip;
+ int res;
+
+#ifdef CONFIG_MTD_PARTITIONS
+ struct mtd_partition *partitions = NULL;
+ int num_partitions = 0;
+#endif
+
+ /* 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->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;
+
+ /*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->verify_buf = socrates_nand_verify_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)) {
+ res = -ENXIO;
+ goto out;
+ }
+
+ /* second phase scan */
+ if (nand_scan_tail(mtd)) {
+ res = -ENXIO;
+ goto out;
+ }
+
+#ifdef CONFIG_MTD_PARTITIONS
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+ num_partitions = parse_mtd_partitions(mtd, part_probes,
+ &partitions, 0);
+ if (num_partitions < 0) {
+ res = num_partitions;
+ goto release;
+ }
+#endif
+
+#ifdef CONFIG_MTD_OF_PARTS
+ if (num_partitions == 0) {
+ num_partitions = of_mtd_parse_partitions(&ofdev->dev,
+ ofdev->node,
+ &partitions);
+ if (num_partitions < 0) {
+ res = num_partitions;
+ goto release;
+ }
+ }
+#endif
+ if (partitions && (num_partitions > 0))
+ res = add_mtd_partitions(mtd, partitions, num_partitions);
+ else
+#endif
+ res = add_mtd_device(mtd);
+
+ if (!res)
+ return res;
+
+#ifdef CONFIG_MTD_PARTITIONS
+release:
+#endif
+ 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 of_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 struct of_device_id socrates_nand_match[] =
+{
+ {
+ .compatible = "abb,socrates-nand",
+ },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, socrates_nand_match);
+
+static struct of_platform_driver socrates_nand_driver = {
+ .name = "socrates_nand",
+ .match_table = socrates_nand_match,
+ .probe = socrates_nand_probe,
+ .remove = __devexit_p(socrates_nand_remove),
+};
+
+static int __init socrates_nand_init(void)
+{
+ return of_register_platform_driver(&socrates_nand_driver);
+}
+
+static void __exit socrates_nand_exit(void)
+{
+ of_unregister_platform_driver(&socrates_nand_driver);
+}
+
+module_init(socrates_nand_init);
+module_exit(socrates_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ilya Yanok");
+MODULE_DESCRIPTION("NAND driver for Socrates board");
git.openpandora.org / pandora-kernel.git / commitdiff