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path: root/drivers/mtd/nand/raw/xway_nand.c
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Diffstat (limited to 'drivers/mtd/nand/raw/xway_nand.c')
-rw-r--r--drivers/mtd/nand/raw/xway_nand.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/xway_nand.c b/drivers/mtd/nand/raw/xway_nand.c
new file mode 100644
index 000000000000..9926b4e3d69d
--- /dev/null
+++ b/drivers/mtd/nand/raw/xway_nand.c
@@ -0,0 +1,245 @@
+/*
+ * 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.
+ *
+ * Copyright © 2012 John Crispin <john@phrozen.org>
+ * Copyright © 2016 Hauke Mehrtens <hauke@hauke-m.de>
+ */
+
+#include <linux/mtd/rawnand.h>
+#include <linux/of_gpio.h>
+#include <linux/of_platform.h>
+
+#include <lantiq_soc.h>
+
+/* nand registers */
+#define EBU_ADDSEL1 0x24
+#define EBU_NAND_CON 0xB0
+#define EBU_NAND_WAIT 0xB4
+#define NAND_WAIT_RD BIT(0) /* NAND flash status output */
+#define NAND_WAIT_WR_C BIT(3) /* NAND Write/Read complete */
+#define EBU_NAND_ECC0 0xB8
+#define EBU_NAND_ECC_AC 0xBC
+
+/*
+ * nand commands
+ * The pins of the NAND chip are selected based on the address bits of the
+ * "register" read and write. There are no special registers, but an
+ * address range and the lower address bits are used to activate the
+ * correct line. For example when the bit (1 << 2) is set in the address
+ * the ALE pin will be activated.
+ */
+#define NAND_CMD_ALE BIT(2) /* address latch enable */
+#define NAND_CMD_CLE BIT(3) /* command latch enable */
+#define NAND_CMD_CS BIT(4) /* chip select */
+#define NAND_CMD_SE BIT(5) /* spare area access latch */
+#define NAND_CMD_WP BIT(6) /* write protect */
+#define NAND_WRITE_CMD (NAND_CMD_CS | NAND_CMD_CLE)
+#define NAND_WRITE_ADDR (NAND_CMD_CS | NAND_CMD_ALE)
+#define NAND_WRITE_DATA (NAND_CMD_CS)
+#define NAND_READ_DATA (NAND_CMD_CS)
+
+/* we need to tel the ebu which addr we mapped the nand to */
+#define ADDSEL1_MASK(x) (x << 4)
+#define ADDSEL1_REGEN 1
+
+/* we need to tell the EBU that we have nand attached and set it up properly */
+#define BUSCON1_SETUP (1 << 22)
+#define BUSCON1_BCGEN_RES (0x3 << 12)
+#define BUSCON1_WAITWRC2 (2 << 8)
+#define BUSCON1_WAITRDC2 (2 << 6)
+#define BUSCON1_HOLDC1 (1 << 4)
+#define BUSCON1_RECOVC1 (1 << 2)
+#define BUSCON1_CMULT4 1
+
+#define NAND_CON_CE (1 << 20)
+#define NAND_CON_OUT_CS1 (1 << 10)
+#define NAND_CON_IN_CS1 (1 << 8)
+#define NAND_CON_PRE_P (1 << 7)
+#define NAND_CON_WP_P (1 << 6)
+#define NAND_CON_SE_P (1 << 5)
+#define NAND_CON_CS_P (1 << 4)
+#define NAND_CON_CSMUX (1 << 1)
+#define NAND_CON_NANDM 1
+
+struct xway_nand_data {
+ struct nand_chip chip;
+ unsigned long csflags;
+ void __iomem *nandaddr;
+};
+
+static u8 xway_readb(struct mtd_info *mtd, int op)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct xway_nand_data *data = nand_get_controller_data(chip);
+
+ return readb(data->nandaddr + op);
+}
+
+static void xway_writeb(struct mtd_info *mtd, int op, u8 value)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct xway_nand_data *data = nand_get_controller_data(chip);
+
+ writeb(value, data->nandaddr + op);
+}
+
+static void xway_select_chip(struct mtd_info *mtd, int select)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct xway_nand_data *data = nand_get_controller_data(chip);
+
+ switch (select) {
+ case -1:
+ ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON);
+ ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON);
+ spin_unlock_irqrestore(&ebu_lock, data->csflags);
+ break;
+ case 0:
+ spin_lock_irqsave(&ebu_lock, data->csflags);
+ ltq_ebu_w32_mask(0, NAND_CON_NANDM, EBU_NAND_CON);
+ ltq_ebu_w32_mask(0, NAND_CON_CE, EBU_NAND_CON);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static void xway_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+ if (cmd == NAND_CMD_NONE)
+ return;
+
+ if (ctrl & NAND_CLE)
+ xway_writeb(mtd, NAND_WRITE_CMD, cmd);
+ else if (ctrl & NAND_ALE)
+ xway_writeb(mtd, NAND_WRITE_ADDR, cmd);
+
+ while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+ ;
+}
+
+static int xway_dev_ready(struct mtd_info *mtd)
+{
+ return ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_RD;
+}
+
+static unsigned char xway_read_byte(struct mtd_info *mtd)
+{
+ return xway_readb(mtd, NAND_READ_DATA);
+}
+
+static void xway_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ buf[i] = xway_readb(mtd, NAND_WRITE_DATA);
+}
+
+static void xway_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ xway_writeb(mtd, NAND_WRITE_DATA, buf[i]);
+}
+
+/*
+ * Probe for the NAND device.
+ */
+static int xway_nand_probe(struct platform_device *pdev)
+{
+ struct xway_nand_data *data;
+ struct mtd_info *mtd;
+ struct resource *res;
+ int err;
+ u32 cs;
+ u32 cs_flag = 0;
+
+ /* Allocate memory for the device structure (and zero it) */
+ data = devm_kzalloc(&pdev->dev, sizeof(struct xway_nand_data),
+ GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->nandaddr = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(data->nandaddr))
+ return PTR_ERR(data->nandaddr);
+
+ nand_set_flash_node(&data->chip, pdev->dev.of_node);
+ mtd = nand_to_mtd(&data->chip);
+ mtd->dev.parent = &pdev->dev;
+
+ data->chip.cmd_ctrl = xway_cmd_ctrl;
+ data->chip.dev_ready = xway_dev_ready;
+ data->chip.select_chip = xway_select_chip;
+ data->chip.write_buf = xway_write_buf;
+ data->chip.read_buf = xway_read_buf;
+ data->chip.read_byte = xway_read_byte;
+ data->chip.chip_delay = 30;
+
+ data->chip.ecc.mode = NAND_ECC_SOFT;
+ data->chip.ecc.algo = NAND_ECC_HAMMING;
+
+ platform_set_drvdata(pdev, data);
+ nand_set_controller_data(&data->chip, data);
+
+ /* load our CS from the DT. Either we find a valid 1 or default to 0 */
+ err = of_property_read_u32(pdev->dev.of_node, "lantiq,cs", &cs);
+ if (!err && cs == 1)
+ cs_flag = NAND_CON_IN_CS1 | NAND_CON_OUT_CS1;
+
+ /* setup the EBU to run in NAND mode on our base addr */
+ ltq_ebu_w32(CPHYSADDR(data->nandaddr)
+ | ADDSEL1_MASK(3) | ADDSEL1_REGEN, EBU_ADDSEL1);
+
+ ltq_ebu_w32(BUSCON1_SETUP | BUSCON1_BCGEN_RES | BUSCON1_WAITWRC2
+ | BUSCON1_WAITRDC2 | BUSCON1_HOLDC1 | BUSCON1_RECOVC1
+ | BUSCON1_CMULT4, LTQ_EBU_BUSCON1);
+
+ ltq_ebu_w32(NAND_CON_NANDM | NAND_CON_CSMUX | NAND_CON_CS_P
+ | NAND_CON_SE_P | NAND_CON_WP_P | NAND_CON_PRE_P
+ | cs_flag, EBU_NAND_CON);
+
+ /* Scan to find existence of the device */
+ err = nand_scan(mtd, 1);
+ if (err)
+ return err;
+
+ err = mtd_device_register(mtd, NULL, 0);
+ if (err)
+ nand_release(mtd);
+
+ return err;
+}
+
+/*
+ * Remove a NAND device.
+ */
+static int xway_nand_remove(struct platform_device *pdev)
+{
+ struct xway_nand_data *data = platform_get_drvdata(pdev);
+
+ nand_release(nand_to_mtd(&data->chip));
+
+ return 0;
+}
+
+static const struct of_device_id xway_nand_match[] = {
+ { .compatible = "lantiq,nand-xway" },
+ {},
+};
+
+static struct platform_driver xway_nand_driver = {
+ .probe = xway_nand_probe,
+ .remove = xway_nand_remove,
+ .driver = {
+ .name = "lantiq,nand-xway",
+ .of_match_table = xway_nand_match,
+ },
+};
+
+builtin_platform_driver(xway_nand_driver);