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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/mtd/nand/socrates_nand.c
Initial import
Diffstat (limited to 'drivers/mtd/nand/socrates_nand.c')
-rw-r--r--drivers/mtd/nand/socrates_nand.c253
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");