drivers/edac: new i82975x driver

New EDAC driver for the i82975x memory controller chipset Used on ASUS
motherboards

[akpm@linux-foundation.org: fix multiple coding-style bloopers]
Signed-off-by: <arvind@acarlab.com>
Signed-off-by: Ranganathan Desikan <rdesikan@jetzbroadband.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 43570d4..1724c41 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -88,6 +88,13 @@
 	  Support for error detection and correction on the Intel
 	  DP82785P and E7210 server chipsets.
 
+config EDAC_I82975X
+	tristate "Intel 82975x (D82975x)"
+	depends on EDAC_MM_EDAC && PCI && X86
+	help
+	  Support for error detection and correction on the Intel
+	  DP82975x server chipsets.
+
 config EDAC_I3000
 	tristate "Intel 3000/3010"
 	depends on EDAC_MM_EDAC && PCI && X86_32
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index bc437f3..02c09f0 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -23,6 +23,7 @@
 obj-$(CONFIG_EDAC_E752X)		+= e752x_edac.o
 obj-$(CONFIG_EDAC_I82443BXGX)		+= i82443bxgx_edac.o
 obj-$(CONFIG_EDAC_I82875P)		+= i82875p_edac.o
+obj-$(CONFIG_EDAC_I82975X)		+= i82975x_edac.o
 obj-$(CONFIG_EDAC_I3000)		+= i3000_edac.o
 obj-$(CONFIG_EDAC_I82860)		+= i82860_edac.o
 obj-$(CONFIG_EDAC_R82600)		+= r82600_edac.o
diff --git a/drivers/edac/i82975x_edac.c b/drivers/edac/i82975x_edac.c
new file mode 100644
index 0000000..0ee8884
--- /dev/null
+++ b/drivers/edac/i82975x_edac.c
@@ -0,0 +1,666 @@
+/*
+ * Intel 82975X Memory Controller kernel module
+ * (C) 2007 aCarLab (India) Pvt. Ltd. (http://acarlab.com)
+ * (C) 2007 jetzbroadband (http://jetzbroadband.com)
+ * This file may be distributed under the terms of the
+ * GNU General Public License.
+ *
+ * Written by Arvind R.
+ *   Copied from i82875p_edac.c source:
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/slab.h>
+
+#include "edac_core.h"
+
+#define I82975X_REVISION	" Ver: 1.0.0 " __DATE__
+#define EDAC_MOD_STR		"i82975x_edac"
+
+#define i82975x_printk(level, fmt, arg...) \
+	edac_printk(level, "i82975x", fmt, ##arg)
+
+#define i82975x_mc_printk(mci, level, fmt, arg...) \
+	edac_mc_chipset_printk(mci, level, "i82975x", fmt, ##arg)
+
+#ifndef PCI_DEVICE_ID_INTEL_82975_0
+#define PCI_DEVICE_ID_INTEL_82975_0	0x277c
+#endif				/* PCI_DEVICE_ID_INTEL_82975_0 */
+
+#define I82975X_NR_CSROWS(nr_chans)		(8/(nr_chans))
+
+/* Intel 82975X register addresses - device 0 function 0 - DRAM Controller */
+#define I82975X_EAP		0x58	/* Dram Error Address Pointer (32b)
+					 *
+					 * 31:7  128 byte cache-line address
+					 * 6:1   reserved
+					 * 0     0: CH0; 1: CH1
+					 */
+
+#define I82975X_DERRSYN		0x5c	/* Dram Error SYNdrome (8b)
+					 *
+					 *  7:0  DRAM ECC Syndrome
+					 */
+
+#define I82975X_DES		0x5d	/* Dram ERRor DeSTination (8b)
+					 * 0h:    Processor Memory Reads
+					 * 1h:7h  reserved
+					 * More - See Page 65 of Intel DocSheet.
+					 */
+
+#define I82975X_ERRSTS		0xc8	/* Error Status Register (16b)
+					 *
+					 * 15:12 reserved
+					 * 11    Thermal Sensor Event
+					 * 10    reserved
+					 *  9    non-DRAM lock error (ndlock)
+					 *  8    Refresh Timeout
+					 *  7:2  reserved
+					 *  1    ECC UE (multibit DRAM error)
+					 *  0    ECC CE (singlebit DRAM error)
+					 */
+
+/* Error Reporting is supported by 3 mechanisms:
+  1. DMI SERR generation  ( ERRCMD )
+  2. SMI DMI  generation  ( SMICMD )
+  3. SCI DMI  generation  ( SCICMD )
+NOTE: Only ONE of the three must be enabled
+*/
+#define I82975X_ERRCMD		0xca	/* Error Command (16b)
+					 *
+					 * 15:12 reserved
+					 * 11    Thermal Sensor Event
+					 * 10    reserved
+					 *  9    non-DRAM lock error (ndlock)
+					 *  8    Refresh Timeout
+					 *  7:2  reserved
+					 *  1    ECC UE (multibit DRAM error)
+					 *  0    ECC CE (singlebit DRAM error)
+					 */
+
+#define I82975X_SMICMD		0xcc	/* Error Command (16b)
+					 *
+					 * 15:2  reserved
+					 *  1    ECC UE (multibit DRAM error)
+					 *  0    ECC CE (singlebit DRAM error)
+					 */
+
+#define I82975X_SCICMD		0xce	/* Error Command (16b)
+					 *
+					 * 15:2  reserved
+					 *  1    ECC UE (multibit DRAM error)
+					 *  0    ECC CE (singlebit DRAM error)
+					 */
+
+#define I82975X_XEAP	0xfc	/* Extended Dram Error Address Pointer (8b)
+					 *
+					 * 7:1   reserved
+					 * 0     Bit32 of the Dram Error Address
+					 */
+
+#define I82975X_MCHBAR		0x44	/*
+					 *
+					 * 31:14 Base Addr of 16K memory-mapped
+					 *	configuration space
+					 * 13:1  reserverd
+					 *  0    mem-mapped config space enable
+					 */
+
+/* NOTE: Following addresses have to indexed using MCHBAR offset (44h, 32b) */
+/* Intel 82975x memory mapped register space */
+
+#define I82975X_DRB_SHIFT 25	/* fixed 32MiB grain */
+
+#define I82975X_DRB		0x100	/* DRAM Row Boundary (8b x 8)
+					 *
+					 * 7   set to 1 in highest DRB of
+					 *	channel if 4GB in ch.
+					 * 6:2 upper boundary of rank in
+					 *	32MB grains
+					 * 1:0 set to 0
+					 */
+#define I82975X_DRB_CH0R0		0x100
+#define I82975X_DRB_CH0R1		0x101
+#define I82975X_DRB_CH0R2		0x102
+#define I82975X_DRB_CH0R3		0x103
+#define I82975X_DRB_CH1R0		0x180
+#define I82975X_DRB_CH1R1		0x181
+#define I82975X_DRB_CH1R2		0x182
+#define I82975X_DRB_CH1R3		0x183
+
+
+#define I82975X_DRA		0x108	/* DRAM Row Attribute (4b x 8)
+					 *  defines the PAGE SIZE to be used
+					 *	for the rank
+					 *  7    reserved
+					 *  6:4  row attr of odd rank, i.e. 1
+					 *  3    reserved
+					 *  2:0  row attr of even rank, i.e. 0
+					 *
+					 * 000 = unpopulated
+					 * 001 = reserved
+					 * 010 = 4KiB
+					 * 011 = 8KiB
+					 * 100 = 16KiB
+					 * others = reserved
+					 */
+#define I82975X_DRA_CH0R01		0x108
+#define I82975X_DRA_CH0R23		0x109
+#define I82975X_DRA_CH1R01		0x188
+#define I82975X_DRA_CH1R23		0x189
+
+
+#define I82975X_BNKARC	0x10e /* Type of device in each rank - Bank Arch (16b)
+					 *
+					 * 15:8  reserved
+					 * 7:6  Rank 3 architecture
+					 * 5:4  Rank 2 architecture
+					 * 3:2  Rank 1 architecture
+					 * 1:0  Rank 0 architecture
+					 *
+					 * 00 => x16 devices; i.e 4 banks
+					 * 01 => x8  devices; i.e 8 banks
+					 */
+#define I82975X_C0BNKARC	0x10e
+#define I82975X_C1BNKARC	0x18e
+
+
+
+#define I82975X_DRC		0x120 /* DRAM Controller Mode0 (32b)
+					 *
+					 * 31:30 reserved
+					 * 29    init complete
+					 * 28:11 reserved, according to Intel
+					 *    22:21 number of channels
+					 *		00=1 01=2 in 82875
+					 *		seems to be ECC mode
+					 *		bits in 82975 in Asus
+					 *		P5W
+					 *	 19:18 Data Integ Mode
+					 *		00=none 01=ECC in 82875
+					 * 10:8  refresh mode
+					 *  7    reserved
+					 *  6:4  mode select
+					 *  3:2  reserved
+					 *  1:0  DRAM type 10=Second Revision
+					 *		DDR2 SDRAM
+					 *         00, 01, 11 reserved
+					 */
+#define I82975X_DRC_CH0M0		0x120
+#define I82975X_DRC_CH1M0		0x1A0
+
+
+#define I82975X_DRC_M1	0x124 /* DRAM Controller Mode1 (32b)
+					 * 31	0=Standard Address Map
+					 *	1=Enhanced Address Map
+					 * 30:0	reserved
+					 */
+
+#define I82975X_DRC_CH0M1		0x124
+#define I82975X_DRC_CH1M1		0x1A4
+
+enum i82975x_chips {
+	I82975X = 0,
+};
+
+struct i82975x_pvt {
+	void __iomem *mch_window;
+};
+
+struct i82975x_dev_info {
+	const char *ctl_name;
+};
+
+struct i82975x_error_info {
+	u16 errsts;
+	u32 eap;
+	u8 des;
+	u8 derrsyn;
+	u16 errsts2;
+	u8 chan;		/* the channel is bit 0 of EAP */
+	u8 xeap;		/* extended eap bit */
+};
+
+static const struct i82975x_dev_info i82975x_devs[] = {
+	[I82975X] = {
+		.ctl_name = "i82975x"
+	},
+};
+
+static struct pci_dev *mci_pdev;	/* init dev: in case that AGP code has
+					 * already registered driver
+					 */
+
+static int i82975x_registered = 1;
+
+static void i82975x_get_error_info(struct mem_ctl_info *mci,
+		struct i82975x_error_info *info)
+{
+	struct pci_dev *pdev;
+
+	pdev = to_pci_dev(mci->dev);
+
+	/*
+	 * This is a mess because there is no atomic way to read all the
+	 * registers at once and the registers can transition from CE being
+	 * overwritten by UE.
+	 */
+	pci_read_config_word(pdev, I82975X_ERRSTS, &info->errsts);
+	pci_read_config_dword(pdev, I82975X_EAP, &info->eap);
+	pci_read_config_byte(pdev, I82975X_XEAP, &info->xeap);
+	pci_read_config_byte(pdev, I82975X_DES, &info->des);
+	pci_read_config_byte(pdev, I82975X_DERRSYN, &info->derrsyn);
+	pci_read_config_word(pdev, I82975X_ERRSTS, &info->errsts2);
+
+	pci_write_bits16(pdev, I82975X_ERRSTS, 0x0003, 0x0003);
+
+	/*
+	 * If the error is the same then we can for both reads then
+	 * the first set of reads is valid.  If there is a change then
+	 * there is a CE no info and the second set of reads is valid
+	 * and should be UE info.
+	 */
+	if (!(info->errsts2 & 0x0003))
+		return;
+
+	if ((info->errsts ^ info->errsts2) & 0x0003) {
+		pci_read_config_dword(pdev, I82975X_EAP, &info->eap);
+		pci_read_config_byte(pdev, I82975X_XEAP, &info->xeap);
+		pci_read_config_byte(pdev, I82975X_DES, &info->des);
+		pci_read_config_byte(pdev, I82975X_DERRSYN,
+				&info->derrsyn);
+	}
+}
+
+static int i82975x_process_error_info(struct mem_ctl_info *mci,
+		struct i82975x_error_info *info, int handle_errors)
+{
+	int row, multi_chan, chan;
+
+	multi_chan = mci->csrows[0].nr_channels - 1;
+
+	if (!(info->errsts2 & 0x0003))
+		return 0;
+
+	if (!handle_errors)
+		return 1;
+
+	if ((info->errsts ^ info->errsts2) & 0x0003) {
+		edac_mc_handle_ce_no_info(mci, "UE overwrote CE");
+		info->errsts = info->errsts2;
+	}
+
+	chan = info->eap & 1;
+	info->eap >>= 1;
+	if (info->xeap )
+		info->eap |= 0x80000000;
+	info->eap >>= PAGE_SHIFT;
+	row = edac_mc_find_csrow_by_page(mci, info->eap);
+
+	if (info->errsts & 0x0002)
+		edac_mc_handle_ue(mci, info->eap, 0, row, "i82975x UE");
+	else
+		edac_mc_handle_ce(mci, info->eap, 0, info->derrsyn, row,
+				multi_chan ? chan : 0,
+				"i82975x CE");
+
+	return 1;
+}
+
+static void i82975x_check(struct mem_ctl_info *mci)
+{
+	struct i82975x_error_info info;
+
+	debugf1("MC%d: %s()\n", mci->mc_idx, __func__);
+	i82975x_get_error_info(mci, &info);
+	i82975x_process_error_info(mci, &info, 1);
+}
+
+/* Return 1 if dual channel mode is active.  Else return 0. */
+static int dual_channel_active(void __iomem *mch_window)
+{
+	/*
+	 * We treat interleaved-symmetric configuration as dual-channel - EAP's
+	 * bit-0 giving the channel of the error location.
+	 *
+	 * All other configurations are treated as single channel - the EAP's
+	 * bit-0 will resolve ok in symmetric area of mixed
+	 * (symmetric/asymmetric) configurations
+	 */
+	u8	drb[4][2];
+	int	row;
+	int    dualch;
+
+	for (dualch = 1, row = 0; dualch && (row < 4); row++) {
+		drb[row][0] = readb(mch_window + I82975X_DRB + row);
+		drb[row][1] = readb(mch_window + I82975X_DRB + row + 0x80);
+		dualch = dualch && (drb[row][0] == drb[row][1]);
+	}
+	return dualch;
+}
+
+static enum dev_type i82975x_dram_type(void __iomem *mch_window, int rank)
+{
+	/*
+	 * ASUS P5W DH either does not program this register or programs
+	 * it wrong!
+	 * ECC is possible on i92975x ONLY with DEV_X8 which should mean 'val'
+	 * for each rank should be 01b - the LSB of the word should be 0x55;
+	 * but it reads 0!
+	 */
+	return DEV_X8;
+}
+
+static void i82975x_init_csrows(struct mem_ctl_info *mci,
+		struct pci_dev *pdev, void __iomem *mch_window)
+{
+	struct csrow_info *csrow;
+	unsigned long last_cumul_size;
+	u8 value;
+	u32 cumul_size;
+	int index;
+
+	last_cumul_size = 0;
+
+	/*
+	 * 82875 comment:
+	 * The dram row boundary (DRB) reg values are boundary address
+	 * for each DRAM row with a granularity of 32 or 64MB (single/dual
+	 * channel operation).  DRB regs are cumulative; therefore DRB7 will
+	 * contain the total memory contained in all eight rows.
+	 *
+	 * FIXME:
+	 *  EDAC currently works for Dual-channel Interleaved configuration.
+	 *  Other configurations, which the chip supports, need fixing/testing.
+	 *
+	 */
+
+	for (index = 0; index < mci->nr_csrows; index++) {
+		csrow = &mci->csrows[index];
+
+		value = readb(mch_window + I82975X_DRB + index +
+					((index >= 4) ? 0x80 : 0));
+		cumul_size = value;
+		cumul_size <<= (I82975X_DRB_SHIFT - PAGE_SHIFT);
+		debugf3("%s(): (%d) cumul_size 0x%x\n", __func__, index,
+			cumul_size);
+		if (cumul_size == last_cumul_size)
+			continue;	/* not populated */
+
+		csrow->first_page = last_cumul_size;
+		csrow->last_page = cumul_size - 1;
+		csrow->nr_pages = cumul_size - last_cumul_size;
+		last_cumul_size = cumul_size;
+		csrow->grain = 1 << 7;	/* I82975X_EAP has 128B resolution */
+		csrow->mtype = MEM_DDR; /* i82975x supports only DDR2 */
+		csrow->dtype = i82975x_dram_type(mch_window, index);
+		csrow->edac_mode = EDAC_SECDED; /* only supported */
+	}
+}
+
+/* #define  i82975x_DEBUG_IOMEM */
+
+#ifdef i82975x_DEBUG_IOMEM
+static void i82975x_print_dram_timings(void __iomem *mch_window)
+{
+	/*
+	 * The register meanings are from Intel specs;
+	 * (shows 13-5-5-5 for 800-DDR2)
+	 * Asus P5W Bios reports 15-5-4-4
+	 * What's your religion?
+	 */
+	static const int caslats[4] = { 5, 4, 3, 6 };
+	u32	dtreg[2];
+
+	dtreg[0] = readl(mch_window + 0x114);
+	dtreg[1] = readl(mch_window + 0x194);
+	i82975x_printk(KERN_INFO, "DRAM Timings :     Ch0    Ch1\n"
+		"                RAS Active Min = %d     %d\n"
+		"                CAS latency    =  %d      %d\n"
+		"                RAS to CAS     =  %d      %d\n"
+		"                RAS precharge  =  %d      %d\n",
+		(dtreg[0] >> 19 ) & 0x0f,
+			(dtreg[1] >> 19) & 0x0f,
+		caslats[(dtreg[0] >> 8) & 0x03],
+			caslats[(dtreg[1] >> 8) & 0x03],
+		((dtreg[0] >> 4) & 0x07) + 2,
+			((dtreg[1] >> 4) & 0x07) + 2,
+		(dtreg[0] & 0x07) + 2,
+			(dtreg[1] & 0x07) + 2
+	);
+
+}
+#endif
+
+static int i82975x_probe1(struct pci_dev *pdev, int dev_idx)
+{
+	int rc = -ENODEV;
+	struct mem_ctl_info *mci;
+	struct i82975x_pvt *pvt;
+	void __iomem *mch_window;
+	u32 mchbar;
+	u32 drc[2];
+	struct i82975x_error_info discard;
+	int	chans;
+#ifdef i82975x_DEBUG_IOMEM
+	u8 c0drb[4];
+	u8 c1drb[4];
+#endif
+
+	debugf0("%s()\n", __func__);
+
+	pci_read_config_dword(pdev, I82975X_MCHBAR, &mchbar);
+	if (!(mchbar & 1)) {
+		debugf3("%s(): failed, MCHBAR disabled!\n", __func__);
+		goto fail0;
+	}
+	mchbar &= 0xffffc000;	/* bits 31:14 used for 16K window */
+	mch_window = ioremap_nocache(mchbar, 0x1000);
+
+#ifdef i82975x_DEBUG_IOMEM
+	i82975x_printk(KERN_INFO, "MCHBAR real = %0x, remapped = %p\n",
+					mchbar, mch_window);
+
+	c0drb[0] = readb(mch_window + I82975X_DRB_CH0R0);
+	c0drb[1] = readb(mch_window + I82975X_DRB_CH0R1);
+	c0drb[2] = readb(mch_window + I82975X_DRB_CH0R2);
+	c0drb[3] = readb(mch_window + I82975X_DRB_CH0R3);
+	c1drb[0] = readb(mch_window + I82975X_DRB_CH1R0);
+	c1drb[1] = readb(mch_window + I82975X_DRB_CH1R1);
+	c1drb[2] = readb(mch_window + I82975X_DRB_CH1R2);
+	c1drb[3] = readb(mch_window + I82975X_DRB_CH1R3);
+	i82975x_printk(KERN_INFO, "DRBCH0R0 = 0x%02x\n", c0drb[0]);
+	i82975x_printk(KERN_INFO, "DRBCH0R1 = 0x%02x\n", c0drb[1]);
+	i82975x_printk(KERN_INFO, "DRBCH0R2 = 0x%02x\n", c0drb[2]);
+	i82975x_printk(KERN_INFO, "DRBCH0R3 = 0x%02x\n", c0drb[3]);
+	i82975x_printk(KERN_INFO, "DRBCH1R0 = 0x%02x\n", c1drb[0]);
+	i82975x_printk(KERN_INFO, "DRBCH1R1 = 0x%02x\n", c1drb[1]);
+	i82975x_printk(KERN_INFO, "DRBCH1R2 = 0x%02x\n", c1drb[2]);
+	i82975x_printk(KERN_INFO, "DRBCH1R3 = 0x%02x\n", c1drb[3]);
+#endif
+
+	drc[0] = readl(mch_window + I82975X_DRC_CH0M0);
+	drc[1] = readl(mch_window + I82975X_DRC_CH1M0);
+#ifdef i82975x_DEBUG_IOMEM
+	i82975x_printk(KERN_INFO, "DRC_CH0 = %0x, %s\n", drc[0],
+			((drc[0] >> 21) & 3) == 1 ?
+				"ECC enabled" : "ECC disabled");
+	i82975x_printk(KERN_INFO, "DRC_CH1 = %0x, %s\n", drc[1],
+			((drc[1] >> 21) & 3) == 1 ?
+				"ECC enabled" : "ECC disabled");
+
+	i82975x_printk(KERN_INFO, "C0 BNKARC = %0x\n",
+		readw(mch_window + I82975X_C0BNKARC));
+	i82975x_printk(KERN_INFO, "C1 BNKARC = %0x\n",
+		readw(mch_window + I82975X_C1BNKARC));
+	i82975x_print_dram_timings(mch_window);
+	goto fail1;
+#endif
+	if (!(((drc[0] >> 21) & 3) == 1 || ((drc[1] >> 21) & 3) == 1)) {
+		i82975x_printk(KERN_INFO, "ECC disabled on both channels.\n");
+		goto fail1;
+	}
+
+	chans = dual_channel_active(mch_window) + 1;
+
+	/* assuming only one controller, index thus is 0 */
+	mci = edac_mc_alloc(sizeof(*pvt), I82975X_NR_CSROWS(chans),
+					chans, 0);
+	if (!mci) {
+		rc = -ENOMEM;
+		goto fail1;
+	}
+
+	debugf3("%s(): init mci\n", __func__);
+	mci->dev = &pdev->dev;
+	mci->mtype_cap = MEM_FLAG_DDR;
+	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
+	mci->edac_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
+	mci->mod_name = EDAC_MOD_STR;
+	mci->mod_ver = I82975X_REVISION;
+	mci->ctl_name = i82975x_devs[dev_idx].ctl_name;
+	mci->edac_check = i82975x_check;
+	mci->ctl_page_to_phys = NULL;
+	debugf3("%s(): init pvt\n", __func__);
+	pvt = (struct i82975x_pvt *) mci->pvt_info;
+	pvt->mch_window = mch_window;
+	i82975x_init_csrows(mci, pdev, mch_window);
+	i82975x_get_error_info(mci, &discard);  /* clear counters */
+
+	/* finalize this instance of memory controller with edac core */
+	if (edac_mc_add_mc(mci)) {
+		debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
+		goto fail2;
+	}
+
+	/* get this far and it's successful */
+	debugf3("%s(): success\n", __func__);
+	return 0;
+
+fail2:
+	edac_mc_free(mci);
+
+fail1:
+	iounmap(mch_window);
+fail0:
+	return rc;
+}
+
+/* returns count (>= 0), or negative on error */
+static int __devinit i82975x_init_one(struct pci_dev *pdev,
+		const struct pci_device_id *ent)
+{
+	int rc;
+
+	debugf0("%s()\n", __func__);
+
+	if (pci_enable_device(pdev) < 0)
+		return -EIO;
+
+	rc = i82975x_probe1(pdev, ent->driver_data);
+
+	if (mci_pdev == NULL)
+		mci_pdev = pci_dev_get(pdev);
+
+	return rc;
+}
+
+static void __devexit i82975x_remove_one(struct pci_dev *pdev)
+{
+	struct mem_ctl_info *mci;
+	struct i82975x_pvt *pvt;
+
+	debugf0("%s()\n", __func__);
+
+	mci = edac_mc_del_mc(&pdev->dev);
+	if (mci  == NULL)
+		return;
+
+	pvt = mci->pvt_info;
+	if (pvt->mch_window)
+		iounmap( pvt->mch_window );
+
+	edac_mc_free(mci);
+}
+
+static const struct pci_device_id i82975x_pci_tbl[] __devinitdata = {
+	{
+		PCI_VEND_DEV(INTEL, 82975_0), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+		I82975X
+	},
+	{
+		0,
+	}	/* 0 terminated list. */
+};
+
+MODULE_DEVICE_TABLE(pci, i82975x_pci_tbl);
+
+static struct pci_driver i82975x_driver = {
+	.name = EDAC_MOD_STR,
+	.probe = i82975x_init_one,
+	.remove = __devexit_p(i82975x_remove_one),
+	.id_table = i82975x_pci_tbl,
+};
+
+static int __init i82975x_init(void)
+{
+	int pci_rc;
+
+	debugf3("%s()\n", __func__);
+
+	pci_rc = pci_register_driver(&i82975x_driver);
+	if (pci_rc < 0)
+		goto fail0;
+
+	if (mci_pdev == NULL) {
+		mci_pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
+				PCI_DEVICE_ID_INTEL_82975_0, NULL);
+
+		if (!mci_pdev) {
+			debugf0("i82975x pci_get_device fail\n");
+			pci_rc = -ENODEV;
+			goto fail1;
+		}
+
+		pci_rc = i82975x_init_one(mci_pdev, i82975x_pci_tbl);
+
+		if (pci_rc < 0) {
+			debugf0("i82975x init fail\n");
+			pci_rc = -ENODEV;
+			goto fail1;
+		}
+	}
+
+	return 0;
+
+fail1:
+	pci_unregister_driver(&i82975x_driver);
+
+fail0:
+	if (mci_pdev != NULL)
+		pci_dev_put(mci_pdev);
+
+	return pci_rc;
+}
+
+static void __exit i82975x_exit(void)
+{
+	debugf3("%s()\n", __func__);
+
+	pci_unregister_driver(&i82975x_driver);
+
+	if (!i82975x_registered) {
+		i82975x_remove_one(mci_pdev);
+		pci_dev_put(mci_pdev);
+	}
+}
+
+module_init(i82975x_init);
+module_exit(i82975x_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arvind R. <arvind@acarlab.com>");
+MODULE_DESCRIPTION("MC support for Intel 82975 memory hub controllers");