[MTD] Basic NAND driver for AMD/NatSemi CS5535/CS5536 Geode companion chip

This lacks hardware ECC support and a few optimisations we're going to
want fairly soon, but it works well enough to mount and use JFFS2.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

drivers/mtd/nand/Kconfig

@@ -189,6 +189,10 @@ config MTD_NAND_SHARPSL
 	tristate "Support for NAND Flash on Sharp SL Series (C7xx + others)"
 	depends on MTD_NAND && ARCH_PXA
 
+config MTD_NAND_CS553X
+	tristate "NAND support for CS5535/CS5536 (AMD Geode companion chip)"
+	depends on MTD_NAND && X86_PC && PCI
+	
 config MTD_NAND_NANDSIM
 	tristate "Support for NAND Flash Simulator"
 	depends on MTD_NAND && MTD_PARTITIONS

drivers/mtd/nand/Makefile

@@ -19,5 +19,6 @@ obj-$(CONFIG_MTD_NAND_RTC_FROM4)	+= rtc_from4.o
 obj-$(CONFIG_MTD_NAND_SHARPSL)		+= sharpsl.o
 obj-$(CONFIG_MTD_NAND_TS7250)		+= ts7250.o
 obj-$(CONFIG_MTD_NAND_NANDSIM)		+= nandsim.o
+obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x_nand.o
 
 nand-objs = nand_base.o nand_bbt.o

drivers/mtd/nand/cs553x_nand.c

@@ -0,0 +1,293 @@
+/*
+ * drivers/mtd/nand/cs553x_nand.c
+ *
+ * (C) 2005, 2006 Red Hat Inc.
+ *
+ * Author: David Woodhouse <dwmw2@infradead.org>
+ *
+ * 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 controller found on 
+ *   the AMD CS5535/CS5536 companion chipsets for the Geode processor.
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/msr.h>
+#include <asm/io.h>
+
+#define NR_CS553X_CONTROLLERS	4
+
+/* NAND Timing MSRs */
+#define MSR_NANDF_DATA		0x5140001b	/* NAND Flash Data Timing MSR */
+#define MSR_NANDF_CTL		0x5140001c	/* NAND Flash Control Timing */
+#define MSR_NANDF_RSVD		0x5140001d	/* Reserved */
+
+/* NAND BAR MSRs */
+#define MSR_DIVIL_LBAR_FLSH0	0x51400010	/* Flash Chip Select 0 */
+#define MSR_DIVIL_LBAR_FLSH1	0x51400011	/* Flash Chip Select 1 */
+#define MSR_DIVIL_LBAR_FLSH2	0x51400012	/* Flash Chip Select 2 */
+#define MSR_DIVIL_LBAR_FLSH3	0x51400013	/* Flash Chip Select 3 */
+	/* Each made up of... */
+#define FLSH_LBAR_EN		(1ULL<<32)
+#define FLSH_NOR_NAND		(1ULL<<33)	/* 1 for NAND */
+#define FLSH_MEM_IO		(1ULL<<34)	/* 1 for MMIO */
+	/* I/O BARs have BASE_ADDR in bits 15:4, IO_MASK in 47:36 */
+	/* MMIO BARs have BASE_ADDR in bits 31:12, MEM_MASK in 63:44 */
+
+/* Pin function selection MSR (IDE vs. flash on the IDE pins) */
+#define MSR_DIVIL_BALL_OPTS	0x51400015
+#define PIN_OPT_IDE		(1<<0)		/* 0 for flash, 1 for IDE */
+
+/* Registers within the NAND flash controller BAR -- memory mapped */
+#define MM_NAND_DATA		0x00	/* 0 to 0x7ff, in fact */
+#define MM_NAND_CTL		0x800	/* Any even address 0x800-0x80e */
+#define MM_NAND_IO		0x801	/* Any odd address 0x801-0x80f */
+#define MM_NAND_STS		0x810
+#define MM_NAND_ECC_LSB		0x811
+#define MM_NAND_ECC_MSB		0x812
+#define MM_NAND_ECC_COL		0x813
+#define MM_NAND_LAC		0x814
+#define MM_NAND_ECC_CTL		0x815
+
+/* Registers within the NAND flash controller BAR -- I/O mapped */
+#define IO_NAND_DATA		0x00	/* 0 to 3, in fact */
+#define IO_NAND_CTL		0x04
+#define IO_NAND_IO		0x05
+#define IO_NAND_STS		0x06
+#define IO_NAND_ECC_CTL		0x08
+#define IO_NAND_ECC_LSB		0x09
+#define IO_NAND_ECC_MSB		0x0a
+#define IO_NAND_ECC_COL		0x0b
+#define IO_NAND_LAC		0x0c
+
+#define CS_NAND_CTL_DIST_EN	(1<<4)	/* Enable NAND Distract interrupt */
+#define CS_NAND_CTL_RDY_INT_MASK	(1<<3)	/* Enable RDY/BUSY# interrupt */
+#define CS_NAND_CTL_ALE		(1<<2)
+#define CS_NAND_CTL_CLE		(1<<1)
+#define CS_NAND_CTL_CE		(1<<0)	/* Keep low; 1 to reset */
+
+#define CS_NAND_STS_FLASH_RDY	(1<<3)
+#define CS_NAND_CTLR_BUSY	(1<<2)
+#define CS_NAND_CMD_COMP	(1<<1)
+#define CS_NAND_DIST_ST		(1<<0)
+
+#define CS_NAND_ECC_PARITY	(1<<2)
+#define CS_NAND_ECC_CLRECC	(1<<1)
+#define CS_NAND_ECC_ENECC	(1<<0)
+
+static unsigned char cs553x_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	unsigned char foo = readb(this->IO_ADDR_R);
+	return foo;
+}
+
+static void cs553x_write_byte(struct mtd_info *mtd, u_char byte)
+{
+	struct nand_chip *this = mtd->priv;
+	int i = 100000;
+
+	while (i && readb(this->IO_ADDR_R + MM_NAND_STS) & CS_NAND_CTLR_BUSY) {
+		udelay(1);
+		i--;
+	}
+	writeb(byte, this->IO_ADDR_W+0x801);
+}
+
+static void cs553x_hwcontrol(struct mtd_info *mtd, int cmd)
+{
+	struct nand_chip *this = mtd->priv;
+	void __iomem *mmio_base = this->IO_ADDR_R;
+
+	uint8_t old = readb(mmio_base + MM_NAND_CTL);
+
+	switch(cmd) {
+	case NAND_CTL_SETCLE:
+		old |= CS_NAND_CTL_CLE;
+		break;
+
+	case NAND_CTL_CLRCLE:
+		old &= ~CS_NAND_CTL_CLE;
+		break;
+
+	case NAND_CTL_SETALE:
+		old |= CS_NAND_CTL_ALE;
+		break;
+
+	case NAND_CTL_CLRALE:
+		old &= ~CS_NAND_CTL_ALE;
+		break;
+
+	case NAND_CTL_SETNCE:
+		old &= ~CS_NAND_CTL_CE;
+		break;
+
+	case NAND_CTL_CLRNCE:
+		old |= CS_NAND_CTL_CE;
+		break;
+	}
+	writeb(old, mmio_base + MM_NAND_CTL);
+}
+
+
+static int cs553x_device_ready(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+	void __iomem *mmio_base = this->IO_ADDR_R;
+	unsigned char foo = readb(mmio_base + MM_NAND_STS);
+
+	return (foo & CS_NAND_STS_FLASH_RDY) && !(foo & CS_NAND_CTLR_BUSY); 
+}
+
+static struct mtd_info *cs553x_mtd[4];
+
+static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
+{
+	int err = 0;
+	struct nand_chip *this;
+	struct mtd_info *new_mtd;
+
+	printk(KERN_NOTICE "Probing CS553x NAND controller CS#%d at %sIO 0x%08lx\n", cs, mmio?"MM":"P", adr);
+
+	if (!mmio) {
+		printk(KERN_NOTICE "PIO mode not yet implemented for CS553X NAND controller\n");
+		return -ENXIO;
+	}
+
+	/* Allocate memory for MTD device structure and private data */
+	new_mtd = kmalloc (sizeof(struct mtd_info) + sizeof (struct nand_chip), GFP_KERNEL);
+	if (!new_mtd) {
+		printk(KERN_WARNING "Unable to allocate CS553X NAND MTD device structure.\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* Get pointer to private data */
+	this = (struct nand_chip *) (&new_mtd[1]);
+
+	/* Initialize structures */
+	memset((char *) new_mtd, 0, sizeof(struct mtd_info));
+	memset((char *) this, 0, sizeof(struct nand_chip));
+
+	/* Link the private data with the MTD structure */
+	new_mtd->priv = this;
+
+	/* map physical address */
+	this->IO_ADDR_R = this->IO_ADDR_W = ioremap(adr, 4096);
+	if (!this->IO_ADDR_R) {
+		printk(KERN_WARNING "ioremap cs553x NAND @0x%08lx failed\n", adr);
+		err = -EIO;
+		goto out_mtd;
+	}
+
+	this->hwcontrol = cs553x_hwcontrol;
+	this->dev_ready = cs553x_device_ready;
+	this->read_byte = cs553x_read_byte;
+	this->write_byte = cs553x_write_byte;
+
+	/* 20 us command delay time */
+	this->chip_delay = 20;
+	this->eccmode = NAND_ECC_SOFT;
+
+	/* Enable the following for a flash based bad block table */
+	//	this->options = NAND_USE_FLASH_BBT;
+
+	/* Scan to find existance of the device */
+	if (nand_scan (new_mtd, 1)) {
+		err = -ENXIO;
+		goto out_ior;
+	}
+
+	cs553x_mtd[cs] = new_mtd;
+	goto out;
+
+out_ior:
+	iounmap((void *)this->IO_ADDR_R);
+out_mtd:
+	kfree (new_mtd);
+out:
+	return err;
+}
+
+int __init cs553x_init(void)
+{
+	int err = -ENXIO;
+	int i;
+	uint64_t val;
+
+	/* Check whether we actually have a CS5535 or CS5536 */
+	if (!pci_find_device(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, NULL) &&
+	    !pci_find_device(PCI_VENDOR_ID_NS,  PCI_DEVICE_ID_NS_CS5535_ISA, NULL))
+		return -ENXIO;
+
+	rdmsrl(MSR_DIVIL_BALL_OPTS, val);
+	if (val & 1) {
+		printk(KERN_INFO "CS553x NAND controller: Flash I/O not enabled in MSR_DIVIL_BALL_OPTS.\n");
+		return -ENXIO;
+	}
+
+	for (i=0; i<NR_CS553X_CONTROLLERS; i++) {
+		rdmsrl(MSR_DIVIL_LBAR_FLSH0+i, val);
+
+		if ((val & (FLSH_LBAR_EN|FLSH_NOR_NAND)) == (FLSH_LBAR_EN|FLSH_NOR_NAND))
+			err = cs553x_init_one(i, !!(val & FLSH_MEM_IO), val & 0xFFFFFFFF);
+	}
+	
+	/* Register all devices together here. This means we can easily hack it to 
+	   do mtdconcat etc. if we want to. */
+	for (i=0; i<NR_CS553X_CONTROLLERS; i++) {
+		if (cs553x_mtd[i]) {
+			add_mtd_device(cs553x_mtd[i]);
+
+			/* If any devices registered, return success. Else the last error. */
+			err = 0;
+		}
+	}
+
+	return err;
+}
+module_init(cs553x_init);
+
+static void __exit cs553x_cleanup (void)
+{
+	int i;
+
+	for (i=0; i<NR_CS553X_CONTROLLERS; i++) {
+		struct mtd_info *mtd = cs553x_mtd[i];
+		struct nand_chip *this;
+		void __iomem *mmio_base;
+
+		if (!mtd)
+			break;
+
+		this = cs553x_mtd[i]->priv;
+		mmio_base = this->IO_ADDR_R;
+
+		/* Release resources, unregister device */
+		nand_release (cs553x_mtd[i]);
+		cs553x_mtd[i] = NULL;
+
+		/* unmap physical adress */
+		iounmap(mmio_base);
+
+		/* Free the MTD device structure */
+		kfree (mtd);
+	}
+}
+module_exit(cs553x_cleanup);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("NAND controller driver for AMD CS5535/CS5536 companion chip");