/* * 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; } static struct platform_nand_data xway_nand_data = { .chip = { .nr_chips = 1, .chip_delay = 30, }, .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);