diff options
Diffstat (limited to 'drivers/mtd/nand/cmx270_nand.c')
| -rw-r--r-- | drivers/mtd/nand/cmx270_nand.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/drivers/mtd/nand/cmx270_nand.c b/drivers/mtd/nand/cmx270_nand.c new file mode 100644 index 0000000..cb663ef --- /dev/null +++ b/drivers/mtd/nand/cmx270_nand.c @@ -0,0 +1,267 @@ +/* + * linux/drivers/mtd/nand/cmx270-nand.c + * + * Copyright (C) 2006 Compulab, Ltd. + * Mike Rapoport <mike@compulab.co.il> + * + * Derived from drivers/mtd/nand/h1910.c + * Copyright (C) 2002 Marius Gröger (mag@sysgo.de) + * Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de) + * + * + * 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. + * + * Overview: + * This is a device driver for the NAND flash device found on the + * CM-X270 board. + */ + +#include <linux/mtd/nand.h> +#include <linux/mtd/partitions.h> + +#include <asm/io.h> +#include <asm/irq.h> + +#include <asm/arch/hardware.h> +#include <asm/arch/pxa-regs.h> + +#define GPIO_NAND_CS (11) +#define GPIO_NAND_RB (89) + +/* This macro needed to ensure in-order operation of GPIO and local + * bus. Without both asm command and dummy uncached read there're + * states when NAND access is broken. I've looked for such macro(s) in + * include/asm-arm but found nothing approptiate. + * dmac_clean_range is close, but is makes cache invalidation + * unnecessary here and it cannot be used in module + */ +#define DRAIN_WB() \ + do { \ + unsigned char dummy; \ + asm volatile ("mcr p15, 0, r0, c7, c10, 4":::"r0"); \ + dummy=*((unsigned char*)UNCACHED_ADDR); \ + } while(0) + +/* MTD structure for CM-X270 board */ +static struct mtd_info *cmx270_nand_mtd; + +/* remaped IO address of the device */ +static void __iomem *cmx270_nand_io; + +/* + * Define static partitions for flash device + */ +static struct mtd_partition partition_info[] = { + [0] = { + .name = "cmx270-0", + .offset = 0, + .size = MTDPART_SIZ_FULL + } +}; +#define NUM_PARTITIONS (ARRAY_SIZE(partition_info)) + +const char *part_probes[] = { "cmdlinepart", NULL }; + +static u_char cmx270_read_byte(struct mtd_info *mtd) +{ + struct nand_chip *this = mtd->priv; + + return (readl(this->IO_ADDR_R) >> 16); +} + +static void cmx270_write_buf(struct mtd_info *mtd, const u_char *buf, int len) +{ + int i; + struct nand_chip *this = mtd->priv; + + for (i=0; i<len; i++) + writel((*buf++ << 16), this->IO_ADDR_W); +} + +static void cmx270_read_buf(struct mtd_info *mtd, u_char *buf, int len) +{ + int i; + struct nand_chip *this = mtd->priv; + + for (i=0; i<len; i++) + *buf++ = readl(this->IO_ADDR_R) >> 16; +} + +static int cmx270_verify_buf(struct mtd_info *mtd, const u_char *buf, int len) +{ + int i; + struct nand_chip *this = mtd->priv; + + for (i=0; i<len; i++) + if (buf[i] != (u_char)(readl(this->IO_ADDR_R) >> 16)) + return -EFAULT; + + return 0; +} + +static inline void nand_cs_on(void) +{ + GPCR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS); +} + +static void nand_cs_off(void) +{ + DRAIN_WB(); + + GPSR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS); +} + +/* + * hardware specific access to control-lines + */ +static void cmx270_hwcontrol(struct mtd_info *mtd, int dat, + unsigned int ctrl) +{ + struct nand_chip* this = mtd->priv; + unsigned int nandaddr = (unsigned int)this->IO_ADDR_W; + + DRAIN_WB(); + + if (ctrl & NAND_CTRL_CHANGE) { + if ( ctrl & NAND_ALE ) + nandaddr |= (1 << 3); + else + nandaddr &= ~(1 << 3); + if ( ctrl & NAND_CLE ) + nandaddr |= (1 << 2); + else + nandaddr &= ~(1 << 2); + if ( ctrl & NAND_NCE ) + nand_cs_on(); + else + nand_cs_off(); + } + + DRAIN_WB(); + this->IO_ADDR_W = (void __iomem*)nandaddr; + if (dat != NAND_CMD_NONE) + writel((dat << 16), this->IO_ADDR_W); + + DRAIN_WB(); +} + +/* + * read device ready pin + */ +static int cmx270_device_ready(struct mtd_info *mtd) +{ + DRAIN_WB(); + + return (GPLR(GPIO_NAND_RB) & GPIO_bit(GPIO_NAND_RB)); +} + +/* + * Main initialization routine + */ +static int cmx270_init(void) +{ + struct nand_chip *this; + const char *part_type; + struct mtd_partition *mtd_parts; + int mtd_parts_nb = 0; + int ret; + + /* Allocate memory for MTD device structure and private data */ + cmx270_nand_mtd = kzalloc(sizeof(struct mtd_info) + + sizeof(struct nand_chip), + GFP_KERNEL); + if (!cmx270_nand_mtd) { + printk("Unable to allocate CM-X270 NAND MTD device structure.\n"); + return -ENOMEM; + } + + cmx270_nand_io = ioremap(PXA_CS1_PHYS, 12); + if (!cmx270_nand_io) { + printk("Unable to ioremap NAND device\n"); + ret = -EINVAL; + goto err1; + } + + /* Get pointer to private data */ + this = (struct nand_chip *)(&cmx270_nand_mtd[1]); + + /* Link the private data with the MTD structure */ + cmx270_nand_mtd->owner = THIS_MODULE; + cmx270_nand_mtd->priv = this; + + /* insert callbacks */ + this->IO_ADDR_R = cmx270_nand_io; + this->IO_ADDR_W = cmx270_nand_io; + this->cmd_ctrl = cmx270_hwcontrol; + this->dev_ready = cmx270_device_ready; + + /* 15 us command delay time */ + this->chip_delay = 20; + this->ecc.mode = NAND_ECC_SOFT; + + /* read/write functions */ + this->read_byte = cmx270_read_byte; + this->read_buf = cmx270_read_buf; + this->write_buf = cmx270_write_buf; + this->verify_buf = cmx270_verify_buf; + + /* Scan to find existence of the device */ + if (nand_scan (cmx270_nand_mtd, 1)) { + printk(KERN_NOTICE "No NAND device\n"); + ret = -ENXIO; + goto err2; + } + +#ifdef CONFIG_MTD_CMDLINE_PARTS + mtd_parts_nb = parse_mtd_partitions(cmx270_nand_mtd, part_probes, + &mtd_parts, 0); + if (mtd_parts_nb > 0) + part_type = "command line"; + else + mtd_parts_nb = 0; +#endif + if (!mtd_parts_nb) { + mtd_parts = partition_info; + mtd_parts_nb = NUM_PARTITIONS; + part_type = "static"; + } + + /* Register the partitions */ + printk(KERN_NOTICE "Using %s partition definition\n", part_type); + ret = add_mtd_partitions(cmx270_nand_mtd, mtd_parts, mtd_parts_nb); + if (ret) + goto err2; + + /* Return happy */ + return 0; + +err2: + iounmap(cmx270_nand_io); +err1: + kfree(cmx270_nand_mtd); + + return ret; + +} +module_init(cmx270_init); + +/* + * Clean up routine + */ +static void cmx270_cleanup(void) +{ + /* Release resources, unregister device */ + nand_release(cmx270_nand_mtd); + + iounmap(cmx270_nand_io); + + /* Free the MTD device structure */ + kfree (cmx270_nand_mtd); +} +module_exit(cmx270_cleanup); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); +MODULE_DESCRIPTION("NAND flash driver for Compulab CM-X270 Module"); |