diff options
Diffstat (limited to 'drivers/mtd/nand/gpio.c')
| -rw-r--r-- | drivers/mtd/nand/gpio.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/drivers/mtd/nand/gpio.c b/drivers/mtd/nand/gpio.c new file mode 100644 index 000000000000..8f902e75aa85 --- /dev/null +++ b/drivers/mtd/nand/gpio.c @@ -0,0 +1,375 @@ +/* + * drivers/mtd/nand/gpio.c + * + * Updated, and converted to generic GPIO based driver by Russell King. + * + * Written by Ben Dooks <ben@simtec.co.uk> + * Based on 2.4 version by Mark Whittaker + * + * © 2004 Simtec Electronics + * + * Device driver for NAND connected via GPIO + * + * 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. + * + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/io.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/nand.h> +#include <linux/mtd/partitions.h> +#include <linux/mtd/nand-gpio.h> + +struct gpiomtd { + void __iomem *io_sync; + struct mtd_info mtd_info; + struct nand_chip nand_chip; + struct gpio_nand_platdata plat; +}; + +#define gpio_nand_getpriv(x) container_of(x, struct gpiomtd, mtd_info) + + +#ifdef CONFIG_ARM +/* gpio_nand_dosync() + * + * Make sure the GPIO state changes occur in-order with writes to NAND + * memory region. + * Needed on PXA due to bus-reordering within the SoC itself (see section on + * I/O ordering in PXA manual (section 2.3, p35) + */ +static void gpio_nand_dosync(struct gpiomtd *gpiomtd) +{ + unsigned long tmp; + + if (gpiomtd->io_sync) { + /* + * Linux memory barriers don't cater for what's required here. + * What's required is what's here - a read from a separate + * region with a dependency on that read. + */ + tmp = readl(gpiomtd->io_sync); + asm volatile("mov %1, %0\n" : "=r" (tmp) : "r" (tmp)); + } +} +#else +static inline void gpio_nand_dosync(struct gpiomtd *gpiomtd) {} +#endif + +static void gpio_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl) +{ + struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd); + + gpio_nand_dosync(gpiomtd); + + if (ctrl & NAND_CTRL_CHANGE) { + gpio_set_value(gpiomtd->plat.gpio_nce, !(ctrl & NAND_NCE)); + gpio_set_value(gpiomtd->plat.gpio_cle, !!(ctrl & NAND_CLE)); + gpio_set_value(gpiomtd->plat.gpio_ale, !!(ctrl & NAND_ALE)); + gpio_nand_dosync(gpiomtd); + } + if (cmd == NAND_CMD_NONE) + return; + + writeb(cmd, gpiomtd->nand_chip.IO_ADDR_W); + gpio_nand_dosync(gpiomtd); +} + +static void gpio_nand_writebuf(struct mtd_info *mtd, const u_char *buf, int len) +{ + struct nand_chip *this = mtd->priv; + + writesb(this->IO_ADDR_W, buf, len); +} + +static void gpio_nand_readbuf(struct mtd_info *mtd, u_char *buf, int len) +{ + struct nand_chip *this = mtd->priv; + + readsb(this->IO_ADDR_R, buf, len); +} + +static int gpio_nand_verifybuf(struct mtd_info *mtd, const u_char *buf, int len) +{ + struct nand_chip *this = mtd->priv; + unsigned char read, *p = (unsigned char *) buf; + int i, err = 0; + + for (i = 0; i < len; i++) { + read = readb(this->IO_ADDR_R); + if (read != p[i]) { + pr_debug("%s: err at %d (read %04x vs %04x)\n", + __func__, i, read, p[i]); + err = -EFAULT; + } + } + return err; +} + +static void gpio_nand_writebuf16(struct mtd_info *mtd, const u_char *buf, + int len) +{ + struct nand_chip *this = mtd->priv; + + if (IS_ALIGNED((unsigned long)buf, 2)) { + writesw(this->IO_ADDR_W, buf, len>>1); + } else { + int i; + unsigned short *ptr = (unsigned short *)buf; + + for (i = 0; i < len; i += 2, ptr++) + writew(*ptr, this->IO_ADDR_W); + } +} + +static void gpio_nand_readbuf16(struct mtd_info *mtd, u_char *buf, int len) +{ + struct nand_chip *this = mtd->priv; + + if (IS_ALIGNED((unsigned long)buf, 2)) { + readsw(this->IO_ADDR_R, buf, len>>1); + } else { + int i; + unsigned short *ptr = (unsigned short *)buf; + + for (i = 0; i < len; i += 2, ptr++) + *ptr = readw(this->IO_ADDR_R); + } +} + +static int gpio_nand_verifybuf16(struct mtd_info *mtd, const u_char *buf, + int len) +{ + struct nand_chip *this = mtd->priv; + unsigned short read, *p = (unsigned short *) buf; + int i, err = 0; + len >>= 1; + + for (i = 0; i < len; i++) { + read = readw(this->IO_ADDR_R); + if (read != p[i]) { + pr_debug("%s: err at %d (read %04x vs %04x)\n", + __func__, i, read, p[i]); + err = -EFAULT; + } + } + return err; +} + + +static int gpio_nand_devready(struct mtd_info *mtd) +{ + struct gpiomtd *gpiomtd = gpio_nand_getpriv(mtd); + return gpio_get_value(gpiomtd->plat.gpio_rdy); +} + +static int __devexit gpio_nand_remove(struct platform_device *dev) +{ + struct gpiomtd *gpiomtd = platform_get_drvdata(dev); + struct resource *res; + + nand_release(&gpiomtd->mtd_info); + + res = platform_get_resource(dev, IORESOURCE_MEM, 1); + iounmap(gpiomtd->io_sync); + if (res) + release_mem_region(res->start, res->end - res->start + 1); + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + iounmap(gpiomtd->nand_chip.IO_ADDR_R); + release_mem_region(res->start, res->end - res->start + 1); + + if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) + gpio_set_value(gpiomtd->plat.gpio_nwp, 0); + gpio_set_value(gpiomtd->plat.gpio_nce, 1); + + gpio_free(gpiomtd->plat.gpio_cle); + gpio_free(gpiomtd->plat.gpio_ale); + gpio_free(gpiomtd->plat.gpio_nce); + if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) + gpio_free(gpiomtd->plat.gpio_nwp); + gpio_free(gpiomtd->plat.gpio_rdy); + + kfree(gpiomtd); + + return 0; +} + +static void __iomem *request_and_remap(struct resource *res, size_t size, + const char *name, int *err) +{ + void __iomem *ptr; + + if (!request_mem_region(res->start, res->end - res->start + 1, name)) { + *err = -EBUSY; + return NULL; + } + + ptr = ioremap(res->start, size); + if (!ptr) { + release_mem_region(res->start, res->end - res->start + 1); + *err = -ENOMEM; + } + return ptr; +} + +static int __devinit gpio_nand_probe(struct platform_device *dev) +{ + struct gpiomtd *gpiomtd; + struct nand_chip *this; + struct resource *res0, *res1; + int ret; + + if (!dev->dev.platform_data) + return -EINVAL; + + res0 = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res0) + return -EINVAL; + + gpiomtd = kzalloc(sizeof(*gpiomtd), GFP_KERNEL); + if (gpiomtd == NULL) { + dev_err(&dev->dev, "failed to create NAND MTD\n"); + return -ENOMEM; + } + + this = &gpiomtd->nand_chip; + this->IO_ADDR_R = request_and_remap(res0, 2, "NAND", &ret); + if (!this->IO_ADDR_R) { + dev_err(&dev->dev, "unable to map NAND\n"); + goto err_map; + } + + res1 = platform_get_resource(dev, IORESOURCE_MEM, 1); + if (res1) { + gpiomtd->io_sync = request_and_remap(res1, 4, "NAND sync", &ret); + if (!gpiomtd->io_sync) { + dev_err(&dev->dev, "unable to map sync NAND\n"); + goto err_sync; + } + } + + memcpy(&gpiomtd->plat, dev->dev.platform_data, sizeof(gpiomtd->plat)); + + ret = gpio_request(gpiomtd->plat.gpio_nce, "NAND NCE"); + if (ret) + goto err_nce; + gpio_direction_output(gpiomtd->plat.gpio_nce, 1); + if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) { + ret = gpio_request(gpiomtd->plat.gpio_nwp, "NAND NWP"); + if (ret) + goto err_nwp; + gpio_direction_output(gpiomtd->plat.gpio_nwp, 1); + } + ret = gpio_request(gpiomtd->plat.gpio_ale, "NAND ALE"); + if (ret) + goto err_ale; + gpio_direction_output(gpiomtd->plat.gpio_ale, 0); + ret = gpio_request(gpiomtd->plat.gpio_cle, "NAND CLE"); + if (ret) + goto err_cle; + gpio_direction_output(gpiomtd->plat.gpio_cle, 0); + ret = gpio_request(gpiomtd->plat.gpio_rdy, "NAND RDY"); + if (ret) + goto err_rdy; + gpio_direction_input(gpiomtd->plat.gpio_rdy); + + + this->IO_ADDR_W = this->IO_ADDR_R; + this->ecc.mode = NAND_ECC_SOFT; + this->options = gpiomtd->plat.options; + this->chip_delay = gpiomtd->plat.chip_delay; + + /* install our routines */ + this->cmd_ctrl = gpio_nand_cmd_ctrl; + this->dev_ready = gpio_nand_devready; + + if (this->options & NAND_BUSWIDTH_16) { + this->read_buf = gpio_nand_readbuf16; + this->write_buf = gpio_nand_writebuf16; + this->verify_buf = gpio_nand_verifybuf16; + } else { + this->read_buf = gpio_nand_readbuf; + this->write_buf = gpio_nand_writebuf; + this->verify_buf = gpio_nand_verifybuf; + } + + /* set the mtd private data for the nand driver */ + gpiomtd->mtd_info.priv = this; + gpiomtd->mtd_info.owner = THIS_MODULE; + + if (nand_scan(&gpiomtd->mtd_info, 1)) { + dev_err(&dev->dev, "no nand chips found?\n"); + ret = -ENXIO; + goto err_wp; + } + + if (gpiomtd->plat.adjust_parts) + gpiomtd->plat.adjust_parts(&gpiomtd->plat, + gpiomtd->mtd_info.size); + + add_mtd_partitions(&gpiomtd->mtd_info, gpiomtd->plat.parts, + gpiomtd->plat.num_parts); + platform_set_drvdata(dev, gpiomtd); + + return 0; + +err_wp: + if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) + gpio_set_value(gpiomtd->plat.gpio_nwp, 0); + gpio_free(gpiomtd->plat.gpio_rdy); +err_rdy: + gpio_free(gpiomtd->plat.gpio_cle); +err_cle: + gpio_free(gpiomtd->plat.gpio_ale); +err_ale: + if (gpio_is_valid(gpiomtd->plat.gpio_nwp)) + gpio_free(gpiomtd->plat.gpio_nwp); +err_nwp: + gpio_free(gpiomtd->plat.gpio_nce); +err_nce: + iounmap(gpiomtd->io_sync); + if (res1) + release_mem_region(res1->start, res1->end - res1->start + 1); +err_sync: + iounmap(gpiomtd->nand_chip.IO_ADDR_R); + release_mem_region(res0->start, res0->end - res0->start + 1); +err_map: + kfree(gpiomtd); + return ret; +} + +static struct platform_driver gpio_nand_driver = { + .probe = gpio_nand_probe, + .remove = gpio_nand_remove, + .driver = { + .name = "gpio-nand", + }, +}; + +static int __init gpio_nand_init(void) +{ + printk(KERN_INFO "GPIO NAND driver, © 2004 Simtec Electronics\n"); + + return platform_driver_register(&gpio_nand_driver); +} + +static void __exit gpio_nand_exit(void) +{ + platform_driver_unregister(&gpio_nand_driver); +} + +module_init(gpio_nand_init); +module_exit(gpio_nand_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); +MODULE_DESCRIPTION("GPIO NAND Driver"); |