diff options
Diffstat (limited to 'drivers/mtd/nand/xway_nand.c')
| -rw-r--r-- | drivers/mtd/nand/xway_nand.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/mtd/nand/xway_nand.c b/drivers/mtd/nand/xway_nand.c new file mode 100644 index 00000000000..3f81dc8f214 --- /dev/null +++ b/drivers/mtd/nand/xway_nand.c @@ -0,0 +1,201 @@ +/* + * 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 <blogic@openwrt.org> + */ + +#include <linux/mtd/nand.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 EBU_NAND_ECC0 0xB8 +#define EBU_NAND_ECC_AC 0xBC + +/* nand commands */ +#define NAND_CMD_ALE (1 << 2) +#define NAND_CMD_CLE (1 << 3) +#define NAND_CMD_CS (1 << 4) +#define NAND_WRITE_CMD_RESET 0xff +#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) +#define NAND_WAIT_WR_C (1 << 3) +#define NAND_WAIT_RD (0x1) + +/* 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 + +static void xway_reset_chip(struct nand_chip *chip) +{ + unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W; + unsigned long flags; + + nandaddr &= ~NAND_WRITE_ADDR; + nandaddr |= NAND_WRITE_CMD; + + /* finish with a reset */ + spin_lock_irqsave(&ebu_lock, flags); + writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr); + while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0) + ; + spin_unlock_irqrestore(&ebu_lock, flags); +} + +static void xway_select_chip(struct mtd_info *mtd, int chip) +{ + + switch (chip) { + case -1: + ltq_ebu_w32_mask(NAND_CON_CE, 0, EBU_NAND_CON); + ltq_ebu_w32_mask(NAND_CON_NANDM, 0, EBU_NAND_CON); + break; + case 0: + 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) +{ + struct nand_chip *this = mtd->priv; + unsigned long nandaddr = (unsigned long) this->IO_ADDR_W; + unsigned long flags; + + if (ctrl & NAND_CTRL_CHANGE) { + nandaddr &= ~(NAND_WRITE_CMD | NAND_WRITE_ADDR); + if (ctrl & NAND_CLE) + nandaddr |= NAND_WRITE_CMD; + else + nandaddr |= NAND_WRITE_ADDR; + this->IO_ADDR_W = (void __iomem *) nandaddr; + } + + if (cmd != NAND_CMD_NONE) { + spin_lock_irqsave(&ebu_lock, flags); + writeb(cmd, this->IO_ADDR_W); + while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0) + ; + spin_unlock_irqrestore(&ebu_lock, flags); + } +} + +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) +{ + struct nand_chip *this = mtd->priv; + unsigned long nandaddr = (unsigned long) this->IO_ADDR_R; + unsigned long flags; + int ret; + + spin_lock_irqsave(&ebu_lock, flags); + ret = ltq_r8((void __iomem *)(nandaddr + NAND_READ_DATA)); + spin_unlock_irqrestore(&ebu_lock, flags); + + return ret; +} + +static int xway_nand_probe(struct platform_device *pdev) +{ + struct nand_chip *this = platform_get_drvdata(pdev); + unsigned long nandaddr = (unsigned long) this->IO_ADDR_W; + const __be32 *cs = of_get_property(pdev->dev.of_node, + "lantiq,cs", NULL); + u32 cs_flag = 0; + + /* load our CS from the DT. Either we find a valid 1 or default to 0 */ + if (cs && (*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(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); + + /* finish with a reset */ + xway_reset_chip(this); + + return 0; +} + +/* allow users to override the partition in DT using the cmdline */ +static const char *part_probes[] = { "cmdlinepart", "ofpart", NULL }; + +static struct platform_nand_data xway_nand_data = { + .chip = { + .nr_chips = 1, + .chip_delay = 30, + .part_probe_types = part_probes, + }, + .ctrl = { + .probe = xway_nand_probe, + .cmd_ctrl = xway_cmd_ctrl, + .dev_ready = xway_dev_ready, + .select_chip = xway_select_chip, + .read_byte = xway_read_byte, + } +}; + +/* + * Try to find the node inside the DT. If it is available attach out + * platform_nand_data + */ +static int __init xway_register_nand(void) +{ + struct device_node *node; + struct platform_device *pdev; + + node = of_find_compatible_node(NULL, NULL, "lantiq,nand-xway"); + if (!node) + return -ENOENT; + pdev = of_find_device_by_node(node); + if (!pdev) + return -EINVAL; + pdev->dev.platform_data = &xway_nand_data; + of_node_put(node); + return 0; +} + +subsys_initcall(xway_register_nand); |