[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>

3 files changed, 298 insertions, 0 deletions

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index b735ab61c1e7..4a1db31aef6a 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/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
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 073705bc8c2d..0741d739cb87 100644
--- a/drivers/mtd/nand/Makefile
+++ b/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
diff --git a/drivers/mtd/nand/cs553x_nand.c b/drivers/mtd/nand/cs553x_nand.c
new file mode 100644
index 000000000000..91207a45ad55
--- /dev/null
+++ b/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");