NAND driver for AT91RM9200
Andrew Victor
andrew at sanpeople.com
Tue Feb 21 03:06:34 EST 2006
hi,
Here is an updated driver which fixes Ben and Thomas' comments:
* Don't need to re-cast 'host->io_base' to 'void __iomem'
* Don't override the cmdfunc from nand_base.c
* Fixed error handling in probe function
Hopefully the driver is now acceptable for addition to the MTD CVS /
mainline kernels. Thanks.
Regards,
Andrew Victor
diff -urN linux-2.6.16-rc4.orig/drivers/mtd/nand/Kconfig linux-2.6.16-rc4/drivers/mtd/nand/Kconfig
--- linux-2.6.16-rc4.orig/drivers/mtd/nand/Kconfig Mon Feb 20 14:40:22 2006
+++ linux-2.6.16-rc4/drivers/mtd/nand/Kconfig Mon Feb 20 16:41:51 2006
@@ -190,5 +190,11 @@
help
The simulator may simulate verious NAND flash chips for the
MTD nand layer.
-
+
+config MTD_NAND_AT91
+ bool "AT91 NAND Access (Smart Media)"
+ depends on MTD_NAND && ARCH_AT91RM9200 && EXPERIMENTAL
+ help
+ Enables access to the Smart Media Card interface on the AT91RM9200
+
endmenu
diff -urN linux-2.6.16-rc4.orig/drivers/mtd/nand/Makefile linux-2.6.16-rc4/drivers/mtd/nand/Makefile
--- linux-2.6.16-rc4.orig/drivers/mtd/nand/Makefile Mon Feb 20 14:35:48 2006
+++ linux-2.6.16-rc4/drivers/mtd/nand/Makefile Mon Feb 20 14:47:11 2006
@@ -18,5 +18,6 @@
obj-$(CONFIG_MTD_NAND_RTC_FROM4) += rtc_from4.o
obj-$(CONFIG_MTD_NAND_SHARPSL) += sharpsl.o
obj-$(CONFIG_MTD_NAND_NANDSIM) += nandsim.o
+obj-$(CONFIG_MTD_NAND_AT91) += at91_nand.o
nand-objs = nand_base.o nand_bbt.o
diff -urN linux-2.6.16-rc4.orig/drivers/mtd/nand/at91_nand.c linux-2.6.16-rc4/drivers/mtd/nand/at91_nand.c
--- linux-2.6.16-rc4.orig/drivers/mtd/nand/at91_nand.c Thu Jan 1 02:00:00 1970
+++ linux-2.6.16-rc4/drivers/mtd/nand/at91_nand.c Tue Feb 21 09:33:26 2006
@@ -0,0 +1,244 @@
+/*
+ * drivers/mtd/nand/at91_nand.c
+ *
+ * Copyright (C) 2003 Rick Bronson
+ *
+ * Derived from drivers/mtd/nand/autcpu12.c
+ * Copyright (c) 2001 Thomas Gleixner (gleixner at autronix.de)
+ *
+ * Derived from drivers/mtd/spia.c
+ * Copyright (C) 2000 Steven J. Hill (sjhill at cotw.com)
+ *
+ * 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/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/io.h>
+#include <asm/sizes.h>
+
+#include <asm/arch/hardware.h>
+#include <asm/arch/board.h>
+#include <asm/arch/gpio.h>
+
+struct at91_nand_host {
+ struct nand_chip nand_chip;
+ struct mtd_info mtd;
+ void __iomem *io_base;
+ struct at91_nand_data *board;
+};
+
+/*
+ * Hardware specific access to control-lines
+ */
+static void at91_nand_hwcontrol(struct mtd_info *mtd, int cmd)
+{
+ struct nand_chip *nand_chip = mtd->priv;
+ struct at91_nand_host *host = nand_chip->priv;
+
+ switch(cmd) {
+ case NAND_CTL_SETCLE:
+ nand_chip->IO_ADDR_W = host->io_base + (1 << host->board->cle);
+ break;
+ case NAND_CTL_CLRCLE:
+ nand_chip->IO_ADDR_W = host->io_base;
+ break;
+ case NAND_CTL_SETALE:
+ nand_chip->IO_ADDR_W = host->io_base + (1 << host->board->ale);
+ break;
+ case NAND_CTL_CLRALE:
+ nand_chip->IO_ADDR_W = host->io_base;
+ break;
+ case NAND_CTL_SETNCE:
+ break;
+ case NAND_CTL_CLRNCE:
+ break;
+ }
+}
+
+/*
+ * Read the Device Ready pin.
+ */
+static int at91_nand_device_ready(struct mtd_info *mtd)
+{
+ struct nand_chip *nand_chip = mtd->priv;
+ struct at91_nand_host *host = nand_chip->priv;
+
+ return at91_get_gpio_value(host->board->rdy_pin);
+}
+
+/*
+ * Enable NAND and detect card.
+ */
+static void at91_nand_enable(struct at91_nand_host *host)
+{
+ unsigned int csa;
+
+ /* Setup Smart Media, first enable the address range of CS3 */
+ csa = at91_sys_read(AT91_EBI_CSA);
+ at91_sys_write(AT91_EBI_CSA, csa | AT91_EBI_CS3A_SMC_SMARTMEDIA);
+
+ /* set the bus interface characteristics */
+ at91_sys_write(AT91_SMC_CSR(3), AT91_SMC_ACSS_STD | AT91_SMC_DBW_8 | AT91_SMC_WSEN
+ | AT91_SMC_NWS_(5)
+ | AT91_SMC_TDF_(1)
+ | AT91_SMC_RWSETUP_(0) /* tDS Data Set up Time 30 - ns */
+ | AT91_SMC_RWHOLD_(1) /* tDH Data Hold Time 20 - ns */
+ );
+
+ if (host->board->enable_pin)
+ at91_set_gpio_value(host->board->enable_pin, 0);
+}
+
+/*
+ * Disable NAND.
+ */
+static void at91_nand_disable(struct at91_nand_host *host)
+{
+ if (host->board->enable_pin)
+ at91_set_gpio_value(host->board->enable_pin, 1);
+}
+
+/*
+ * Probe for the NAND device.
+ */
+static int __init at91_nand_probe(struct platform_device *pdev)
+{
+ struct at91_nand_host *host;
+ struct mtd_info *mtd;
+ struct nand_chip *nand_chip;
+ int res;
+
+#ifdef CONFIG_MTD_PARTITIONS
+ struct mtd_partition *partitions = NULL;
+ int num_partitions = 0;
+#endif
+
+ /* Allocate memory for the device structure */
+ host = kmalloc(sizeof(struct at91_nand_host), GFP_KERNEL);
+ if (!host) {
+ printk(KERN_ERR "at91_nand: failed to allocate device structure.\n");
+ return -ENOMEM;
+ }
+ memset(host, 0, sizeof(struct at91_nand_host));
+
+ host->io_base = ioremap(pdev->resource[0].start,
+ pdev->resource[0].end - pdev->resource[0].start + 1);
+ if (host->io_base == NULL) {
+ printk(KERN_ERR "at91_nand: ioremap failed\n");
+ kfree(host);
+ return -EIO;
+ }
+
+ mtd = &host->mtd;
+ nand_chip = &host->nand_chip;
+ host->board = pdev->dev.platform_data;
+
+ nand_chip->priv = host; /* link the private data structures */
+ mtd->priv = nand_chip;
+
+ /* Set address of NAND IO lines */
+ nand_chip->IO_ADDR_R = host->io_base;
+ nand_chip->IO_ADDR_W = host->io_base;
+ nand_chip->hwcontrol = at91_nand_hwcontrol;
+ nand_chip->dev_ready = at91_nand_device_ready;
+ nand_chip->eccmode = NAND_ECC_SOFT; /* enable ECC */
+ nand_chip->chip_delay = 20; /* 20us command delay time */
+
+ platform_set_drvdata(pdev, host);
+ at91_nand_enable(host);
+
+ if (host->board->det_pin) {
+ if (at91_get_gpio_value(host->board->det_pin)) {
+ printk ("No SmartMedia card inserted.\n");
+ res = ENXIO;
+ goto out;
+ }
+ }
+
+ /* Scan to find existance of the device */
+ if (nand_scan(mtd, 1)) {
+ res = -ENXIO;
+ goto out;
+ }
+
+#ifdef CONFIG_MTD_PARTITIONS
+ if (host->board->partition_info)
+ partitions = host->board->partition_info(mtd->size, &num_partitions);
+
+ if ((!partitions) || (num_partitions == 0)) {
+ printk(KERN_ERR "at91_nand: No parititions defined, or unsupported device.\n");
+ res = ENXIO;
+ goto out;
+ }
+
+ res = add_mtd_partitions(mtd, partitions, num_partitions);
+#else
+ res = add_mtd_device(mtd);
+#endif
+
+out:
+ if (res) {
+ at91_nand_disable(host);
+ platform_set_drvdata(pdev, NULL);
+
+ iounmap(host->io_base);
+ kfree(host);
+ }
+
+ return res;
+}
+
+/*
+ * Remove a NAND device.
+ */
+static int __devexit at91_nand_remove(struct platform_device *pdev)
+{
+ struct at91_nand_host *host = platform_get_drvdata(pdev);
+ struct mtd_info *mtd = &host->mtd;
+
+ del_mtd_partitions(mtd);
+ del_mtd_device(mtd);
+
+ at91_nand_disable(host);
+
+ iounmap(host->io_base);
+ kfree(host);
+
+ return 0;
+}
+
+static struct platform_driver at91_nand_driver = {
+ .probe = at91_nand_probe,
+ .remove = at91_nand_remove,
+ .driver = {
+ .name = "at91_nand",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init at91_nand_init(void)
+{
+ return platform_driver_register(&at91_nand_driver);
+}
+
+static void __exit at91_nand_exit(void)
+{
+ platform_driver_unregister(&at91_nand_driver);
+}
+
+
+module_init(at91_nand_init);
+module_exit(at91_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rick Bronson");
+MODULE_DESCRIPTION("Glue layer for SmartMediaCard on ATMEL AT91RM9200");
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