diff options
Diffstat (limited to 'drivers/mtd/nand/raw/xway_nand.c')
| -rw-r--r-- | drivers/mtd/nand/raw/xway_nand.c | 245 |
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 000000000..bfa43fdc3 --- /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(&data->chip, 1); + if (err) + return err; + + err = mtd_device_register(mtd, NULL, 0); + if (err) + nand_cleanup(&data->chip); + + 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(&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); |