Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1096 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/ibmphp_hpc.c b/drivers/pci/hotplug/ibmphp_hpc.c
new file mode 100644
index 000000000..508a62a6b
--- /dev/null
+++ b/drivers/pci/hotplug/ibmphp_hpc.c
@@ -0,0 +1,1096 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IBM Hot Plug Controller Driver
+ *
+ * Written By: Jyoti Shah, IBM Corporation
+ *
+ * Copyright (C) 2001-2003 IBM Corp.
+ *
+ * All rights reserved.
+ *
+ * Send feedback to <gregkh@us.ibm.com>
+ *                  <jshah@us.ibm.com>
+ *
+ */
+
+#include <linux/wait.h>
+#include <linux/time.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/kthread.h>
+#include "ibmphp.h"
+
+static int to_debug = 0;
+#define debug_polling(fmt, arg...)	do { if (to_debug) debug(fmt, arg); } while (0)
+
+//----------------------------------------------------------------------------
+// timeout values
+//----------------------------------------------------------------------------
+#define CMD_COMPLETE_TOUT_SEC	60	// give HPC 60 sec to finish cmd
+#define HPC_CTLR_WORKING_TOUT	60	// give HPC 60 sec to finish cmd
+#define HPC_GETACCESS_TIMEOUT	60	// seconds
+#define POLL_INTERVAL_SEC	2	// poll HPC every 2 seconds
+#define POLL_LATCH_CNT		5	// poll latch 5 times, then poll slots
+
+//----------------------------------------------------------------------------
+// Winnipeg Architected Register Offsets
+//----------------------------------------------------------------------------
+#define WPG_I2CMBUFL_OFFSET	0x08	// I2C Message Buffer Low
+#define WPG_I2CMOSUP_OFFSET	0x10	// I2C Master Operation Setup Reg
+#define WPG_I2CMCNTL_OFFSET	0x20	// I2C Master Control Register
+#define WPG_I2CPARM_OFFSET	0x40	// I2C Parameter Register
+#define WPG_I2CSTAT_OFFSET	0x70	// I2C Status Register
+
+//----------------------------------------------------------------------------
+// Winnipeg Store Type commands (Add this commands to the register offset)
+//----------------------------------------------------------------------------
+#define WPG_I2C_AND		0x1000	// I2C AND operation
+#define WPG_I2C_OR		0x2000	// I2C OR operation
+
+//----------------------------------------------------------------------------
+// Command set for I2C Master Operation Setup Register
+//----------------------------------------------------------------------------
+#define WPG_READATADDR_MASK	0x00010000	// read,bytes,I2C shifted,index
+#define WPG_WRITEATADDR_MASK	0x40010000	// write,bytes,I2C shifted,index
+#define WPG_READDIRECT_MASK	0x10010000
+#define WPG_WRITEDIRECT_MASK	0x60010000
+
+
+//----------------------------------------------------------------------------
+// bit masks for I2C Master Control Register
+//----------------------------------------------------------------------------
+#define WPG_I2CMCNTL_STARTOP_MASK	0x00000002	// Start the Operation
+
+//----------------------------------------------------------------------------
+//
+//----------------------------------------------------------------------------
+#define WPG_I2C_IOREMAP_SIZE	0x2044	// size of linear address interval
+
+//----------------------------------------------------------------------------
+// command index
+//----------------------------------------------------------------------------
+#define WPG_1ST_SLOT_INDEX	0x01	// index - 1st slot for ctlr
+#define WPG_CTLR_INDEX		0x0F	// index - ctlr
+#define WPG_1ST_EXTSLOT_INDEX	0x10	// index - 1st ext slot for ctlr
+#define WPG_1ST_BUS_INDEX	0x1F	// index - 1st bus for ctlr
+
+//----------------------------------------------------------------------------
+// macro utilities
+//----------------------------------------------------------------------------
+// if bits 20,22,25,26,27,29,30 are OFF return 1
+#define HPC_I2CSTATUS_CHECK(s)	((u8)((s & 0x00000A76) ? 0 : 1))
+
+//----------------------------------------------------------------------------
+// global variables
+//----------------------------------------------------------------------------
+static DEFINE_MUTEX(sem_hpcaccess);	// lock access to HPC
+static DEFINE_MUTEX(operations_mutex);	// lock all operations and
+					// access to data structures
+static DECLARE_COMPLETION(exit_complete); // make sure polling thread goes away
+static struct task_struct *ibmphp_poll_thread;
+//----------------------------------------------------------------------------
+// local function prototypes
+//----------------------------------------------------------------------------
+static u8 i2c_ctrl_read(struct controller *, void __iomem *, u8);
+static u8 i2c_ctrl_write(struct controller *, void __iomem *, u8, u8);
+static u8 hpc_writecmdtoindex(u8, u8);
+static u8 hpc_readcmdtoindex(u8, u8);
+static void get_hpc_access(void);
+static void free_hpc_access(void);
+static int poll_hpc(void *data);
+static int process_changeinstatus(struct slot *, struct slot *);
+static int process_changeinlatch(u8, u8, struct controller *);
+static int hpc_wait_ctlr_notworking(int, struct controller *, void __iomem *, u8 *);
+//----------------------------------------------------------------------------
+
+
+/*----------------------------------------------------------------------
+* Name:    i2c_ctrl_read
+*
+* Action:  read from HPC over I2C
+*
+*---------------------------------------------------------------------*/
+static u8 i2c_ctrl_read(struct controller *ctlr_ptr, void __iomem *WPGBbar, u8 index)
+{
+	u8 status;
+	int i;
+	void __iomem *wpg_addr;	// base addr + offset
+	unsigned long wpg_data;	// data to/from WPG LOHI format
+	unsigned long ultemp;
+	unsigned long data;	// actual data HILO format
+
+	debug_polling("%s - Entry WPGBbar[%p] index[%x] \n", __func__, WPGBbar, index);
+
+	//--------------------------------------------------------------------
+	// READ - step 1
+	// read at address, byte length, I2C address (shifted), index
+	// or read direct, byte length, index
+	if (ctlr_ptr->ctlr_type == 0x02) {
+		data = WPG_READATADDR_MASK;
+		// fill in I2C address
+		ultemp = (unsigned long)ctlr_ptr->u.wpeg_ctlr.i2c_addr;
+		ultemp = ultemp >> 1;
+		data |= (ultemp << 8);
+
+		// fill in index
+		data |= (unsigned long)index;
+	} else if (ctlr_ptr->ctlr_type == 0x04) {
+		data = WPG_READDIRECT_MASK;
+
+		// fill in index
+		ultemp = (unsigned long)index;
+		ultemp = ultemp << 8;
+		data |= ultemp;
+	} else {
+		err("this controller type is not supported \n");
+		return HPC_ERROR;
+	}
+
+	wpg_data = swab32(data);	// swap data before writing
+	wpg_addr = WPGBbar + WPG_I2CMOSUP_OFFSET;
+	writel(wpg_data, wpg_addr);
+
+	//--------------------------------------------------------------------
+	// READ - step 2 : clear the message buffer
+	data = 0x00000000;
+	wpg_data = swab32(data);
+	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
+	writel(wpg_data, wpg_addr);
+
+	//--------------------------------------------------------------------
+	// READ - step 3 : issue start operation, I2C master control bit 30:ON
+	//                 2020 : [20] OR operation at [20] offset 0x20
+	data = WPG_I2CMCNTL_STARTOP_MASK;
+	wpg_data = swab32(data);
+	wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET + WPG_I2C_OR;
+	writel(wpg_data, wpg_addr);
+
+	//--------------------------------------------------------------------
+	// READ - step 4 : wait until start operation bit clears
+	i = CMD_COMPLETE_TOUT_SEC;
+	while (i) {
+		msleep(10);
+		wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET;
+		wpg_data = readl(wpg_addr);
+		data = swab32(wpg_data);
+		if (!(data & WPG_I2CMCNTL_STARTOP_MASK))
+			break;
+		i--;
+	}
+	if (i == 0) {
+		debug("%s - Error : WPG timeout\n", __func__);
+		return HPC_ERROR;
+	}
+	//--------------------------------------------------------------------
+	// READ - step 5 : read I2C status register
+	i = CMD_COMPLETE_TOUT_SEC;
+	while (i) {
+		msleep(10);
+		wpg_addr = WPGBbar + WPG_I2CSTAT_OFFSET;
+		wpg_data = readl(wpg_addr);
+		data = swab32(wpg_data);
+		if (HPC_I2CSTATUS_CHECK(data))
+			break;
+		i--;
+	}
+	if (i == 0) {
+		debug("ctrl_read - Exit Error:I2C timeout\n");
+		return HPC_ERROR;
+	}
+
+	//--------------------------------------------------------------------
+	// READ - step 6 : get DATA
+	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
+	wpg_data = readl(wpg_addr);
+	data = swab32(wpg_data);
+
+	status = (u8) data;
+
+	debug_polling("%s - Exit index[%x] status[%x]\n", __func__, index, status);
+
+	return (status);
+}
+
+/*----------------------------------------------------------------------
+* Name:    i2c_ctrl_write
+*
+* Action:  write to HPC over I2C
+*
+* Return   0 or error codes
+*---------------------------------------------------------------------*/
+static u8 i2c_ctrl_write(struct controller *ctlr_ptr, void __iomem *WPGBbar, u8 index, u8 cmd)
+{
+	u8 rc;
+	void __iomem *wpg_addr;	// base addr + offset
+	unsigned long wpg_data;	// data to/from WPG LOHI format
+	unsigned long ultemp;
+	unsigned long data;	// actual data HILO format
+	int i;
+
+	debug_polling("%s - Entry WPGBbar[%p] index[%x] cmd[%x]\n", __func__, WPGBbar, index, cmd);
+
+	rc = 0;
+	//--------------------------------------------------------------------
+	// WRITE - step 1
+	// write at address, byte length, I2C address (shifted), index
+	// or write direct, byte length, index
+	data = 0x00000000;
+
+	if (ctlr_ptr->ctlr_type == 0x02) {
+		data = WPG_WRITEATADDR_MASK;
+		// fill in I2C address
+		ultemp = (unsigned long)ctlr_ptr->u.wpeg_ctlr.i2c_addr;
+		ultemp = ultemp >> 1;
+		data |= (ultemp << 8);
+
+		// fill in index
+		data |= (unsigned long)index;
+	} else if (ctlr_ptr->ctlr_type == 0x04) {
+		data = WPG_WRITEDIRECT_MASK;
+
+		// fill in index
+		ultemp = (unsigned long)index;
+		ultemp = ultemp << 8;
+		data |= ultemp;
+	} else {
+		err("this controller type is not supported \n");
+		return HPC_ERROR;
+	}
+
+	wpg_data = swab32(data);	// swap data before writing
+	wpg_addr = WPGBbar + WPG_I2CMOSUP_OFFSET;
+	writel(wpg_data, wpg_addr);
+
+	//--------------------------------------------------------------------
+	// WRITE - step 2 : clear the message buffer
+	data = 0x00000000 | (unsigned long)cmd;
+	wpg_data = swab32(data);
+	wpg_addr = WPGBbar + WPG_I2CMBUFL_OFFSET;
+	writel(wpg_data, wpg_addr);
+
+	//--------------------------------------------------------------------
+	// WRITE - step 3 : issue start operation,I2C master control bit 30:ON
+	//                 2020 : [20] OR operation at [20] offset 0x20
+	data = WPG_I2CMCNTL_STARTOP_MASK;
+	wpg_data = swab32(data);
+	wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET + WPG_I2C_OR;
+	writel(wpg_data, wpg_addr);
+
+	//--------------------------------------------------------------------
+	// WRITE - step 4 : wait until start operation bit clears
+	i = CMD_COMPLETE_TOUT_SEC;
+	while (i) {
+		msleep(10);
+		wpg_addr = WPGBbar + WPG_I2CMCNTL_OFFSET;
+		wpg_data = readl(wpg_addr);
+		data = swab32(wpg_data);
+		if (!(data & WPG_I2CMCNTL_STARTOP_MASK))
+			break;
+		i--;
+	}
+	if (i == 0) {
+		debug("%s - Exit Error:WPG timeout\n", __func__);
+		rc = HPC_ERROR;
+	}
+
+	//--------------------------------------------------------------------
+	// WRITE - step 5 : read I2C status register
+	i = CMD_COMPLETE_TOUT_SEC;
+	while (i) {
+		msleep(10);
+		wpg_addr = WPGBbar + WPG_I2CSTAT_OFFSET;
+		wpg_data = readl(wpg_addr);
+		data = swab32(wpg_data);
+		if (HPC_I2CSTATUS_CHECK(data))
+			break;
+		i--;
+	}
+	if (i == 0) {
+		debug("ctrl_read - Error : I2C timeout\n");
+		rc = HPC_ERROR;
+	}
+
+	debug_polling("%s Exit rc[%x]\n", __func__, rc);
+	return (rc);
+}
+
+//------------------------------------------------------------
+//  Read from ISA type HPC
+//------------------------------------------------------------
+static u8 isa_ctrl_read(struct controller *ctlr_ptr, u8 offset)
+{
+	u16 start_address;
+	u16 end_address;
+	u8 data;
+
+	start_address = ctlr_ptr->u.isa_ctlr.io_start;
+	end_address = ctlr_ptr->u.isa_ctlr.io_end;
+	data = inb(start_address + offset);
+	return data;
+}
+
+//--------------------------------------------------------------
+// Write to ISA type HPC
+//--------------------------------------------------------------
+static void isa_ctrl_write(struct controller *ctlr_ptr, u8 offset, u8 data)
+{
+	u16 start_address;
+	u16 port_address;
+
+	start_address = ctlr_ptr->u.isa_ctlr.io_start;
+	port_address = start_address + (u16) offset;
+	outb(data, port_address);
+}
+
+static u8 pci_ctrl_read(struct controller *ctrl, u8 offset)
+{
+	u8 data = 0x00;
+	debug("inside pci_ctrl_read\n");
+	if (ctrl->ctrl_dev)
+		pci_read_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, &data);
+	return data;
+}
+
+static u8 pci_ctrl_write(struct controller *ctrl, u8 offset, u8 data)
+{
+	u8 rc = -ENODEV;
+	debug("inside pci_ctrl_write\n");
+	if (ctrl->ctrl_dev) {
+		pci_write_config_byte(ctrl->ctrl_dev, HPC_PCI_OFFSET + offset, data);
+		rc = 0;
+	}
+	return rc;
+}
+
+static u8 ctrl_read(struct controller *ctlr, void __iomem *base, u8 offset)
+{
+	u8 rc;
+	switch (ctlr->ctlr_type) {
+	case 0:
+		rc = isa_ctrl_read(ctlr, offset);
+		break;
+	case 1:
+		rc = pci_ctrl_read(ctlr, offset);
+		break;
+	case 2:
+	case 4:
+		rc = i2c_ctrl_read(ctlr, base, offset);
+		break;
+	default:
+		return -ENODEV;
+	}
+	return rc;
+}
+
+static u8 ctrl_write(struct controller *ctlr, void __iomem *base, u8 offset, u8 data)
+{
+	u8 rc = 0;
+	switch (ctlr->ctlr_type) {
+	case 0:
+		isa_ctrl_write(ctlr, offset, data);
+		break;
+	case 1:
+		rc = pci_ctrl_write(ctlr, offset, data);
+		break;
+	case 2:
+	case 4:
+		rc = i2c_ctrl_write(ctlr, base, offset, data);
+		break;
+	default:
+		return -ENODEV;
+	}
+	return rc;
+}
+/*----------------------------------------------------------------------
+* Name:    hpc_writecmdtoindex()
+*
+* Action:  convert a write command to proper index within a controller
+*
+* Return   index, HPC_ERROR
+*---------------------------------------------------------------------*/
+static u8 hpc_writecmdtoindex(u8 cmd, u8 index)
+{
+	u8 rc;
+
+	switch (cmd) {
+	case HPC_CTLR_ENABLEIRQ:	// 0x00.N.15
+	case HPC_CTLR_CLEARIRQ:	// 0x06.N.15
+	case HPC_CTLR_RESET:	// 0x07.N.15
+	case HPC_CTLR_IRQSTEER:	// 0x08.N.15
+	case HPC_CTLR_DISABLEIRQ:	// 0x01.N.15
+	case HPC_ALLSLOT_ON:	// 0x11.N.15
+	case HPC_ALLSLOT_OFF:	// 0x12.N.15
+		rc = 0x0F;
+		break;
+
+	case HPC_SLOT_OFF:	// 0x02.Y.0-14
+	case HPC_SLOT_ON:	// 0x03.Y.0-14
+	case HPC_SLOT_ATTNOFF:	// 0x04.N.0-14
+	case HPC_SLOT_ATTNON:	// 0x05.N.0-14
+	case HPC_SLOT_BLINKLED:	// 0x13.N.0-14
+		rc = index;
+		break;
+
+	case HPC_BUS_33CONVMODE:
+	case HPC_BUS_66CONVMODE:
+	case HPC_BUS_66PCIXMODE:
+	case HPC_BUS_100PCIXMODE:
+	case HPC_BUS_133PCIXMODE:
+		rc = index + WPG_1ST_BUS_INDEX - 1;
+		break;
+
+	default:
+		err("hpc_writecmdtoindex - Error invalid cmd[%x]\n", cmd);
+		rc = HPC_ERROR;
+	}
+
+	return rc;
+}
+
+/*----------------------------------------------------------------------
+* Name:    hpc_readcmdtoindex()
+*
+* Action:  convert a read command to proper index within a controller
+*
+* Return   index, HPC_ERROR
+*---------------------------------------------------------------------*/
+static u8 hpc_readcmdtoindex(u8 cmd, u8 index)
+{
+	u8 rc;
+
+	switch (cmd) {
+	case READ_CTLRSTATUS:
+		rc = 0x0F;
+		break;
+	case READ_SLOTSTATUS:
+	case READ_ALLSTAT:
+		rc = index;
+		break;
+	case READ_EXTSLOTSTATUS:
+		rc = index + WPG_1ST_EXTSLOT_INDEX;
+		break;
+	case READ_BUSSTATUS:
+		rc = index + WPG_1ST_BUS_INDEX - 1;
+		break;
+	case READ_SLOTLATCHLOWREG:
+		rc = 0x28;
+		break;
+	case READ_REVLEVEL:
+		rc = 0x25;
+		break;
+	case READ_HPCOPTIONS:
+		rc = 0x27;
+		break;
+	default:
+		rc = HPC_ERROR;
+	}
+	return rc;
+}
+
+/*----------------------------------------------------------------------
+* Name:    HPCreadslot()
+*
+* Action:  issue a READ command to HPC
+*
+* Input:   pslot   - cannot be NULL for READ_ALLSTAT
+*          pstatus - can be NULL for READ_ALLSTAT
+*
+* Return   0 or error codes
+*---------------------------------------------------------------------*/
+int ibmphp_hpc_readslot(struct slot *pslot, u8 cmd, u8 *pstatus)
+{
+	void __iomem *wpg_bbar = NULL;
+	struct controller *ctlr_ptr;
+	u8 index, status;
+	int rc = 0;
+	int busindex;
+
+	debug_polling("%s - Entry pslot[%p] cmd[%x] pstatus[%p]\n", __func__, pslot, cmd, pstatus);
+
+	if ((pslot == NULL)
+	    || ((pstatus == NULL) && (cmd != READ_ALLSTAT) && (cmd != READ_BUSSTATUS))) {
+		rc = -EINVAL;
+		err("%s - Error invalid pointer, rc[%d]\n", __func__, rc);
+		return rc;
+	}
+
+	if (cmd == READ_BUSSTATUS) {
+		busindex = ibmphp_get_bus_index(pslot->bus);
+		if (busindex < 0) {
+			rc = -EINVAL;
+			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
+			return rc;
+		} else
+			index = (u8) busindex;
+	} else
+		index = pslot->ctlr_index;
+
+	index = hpc_readcmdtoindex(cmd, index);
+
+	if (index == HPC_ERROR) {
+		rc = -EINVAL;
+		err("%s - Exit Error:invalid index, rc[%d]\n", __func__, rc);
+		return rc;
+	}
+
+	ctlr_ptr = pslot->ctrl;
+
+	get_hpc_access();
+
+	//--------------------------------------------------------------------
+	// map physical address to logical address
+	//--------------------------------------------------------------------
+	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
+		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
+
+	//--------------------------------------------------------------------
+	// check controller status before reading
+	//--------------------------------------------------------------------
+	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
+	if (!rc) {
+		switch (cmd) {
+		case READ_ALLSTAT:
+			// update the slot structure
+			pslot->ctrl->status = status;
+			pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
+			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
+						       &status);
+			if (!rc)
+				pslot->ext_status = ctrl_read(ctlr_ptr, wpg_bbar, index + WPG_1ST_EXTSLOT_INDEX);
+
+			break;
+
+		case READ_SLOTSTATUS:
+			// DO NOT update the slot structure
+			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
+			break;
+
+		case READ_EXTSLOTSTATUS:
+			// DO NOT update the slot structure
+			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
+			break;
+
+		case READ_CTLRSTATUS:
+			// DO NOT update the slot structure
+			*pstatus = status;
+			break;
+
+		case READ_BUSSTATUS:
+			pslot->busstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
+			break;
+		case READ_REVLEVEL:
+			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
+			break;
+		case READ_HPCOPTIONS:
+			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
+			break;
+		case READ_SLOTLATCHLOWREG:
+			// DO NOT update the slot structure
+			*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, index);
+			break;
+
+			// Not used
+		case READ_ALLSLOT:
+			list_for_each_entry(pslot, &ibmphp_slot_head,
+					    ibm_slot_list) {
+				index = pslot->ctlr_index;
+				rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr,
+								wpg_bbar, &status);
+				if (!rc) {
+					pslot->status = ctrl_read(ctlr_ptr, wpg_bbar, index);
+					rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT,
+									ctlr_ptr, wpg_bbar, &status);
+					if (!rc)
+						pslot->ext_status =
+						    ctrl_read(ctlr_ptr, wpg_bbar,
+								index + WPG_1ST_EXTSLOT_INDEX);
+				} else {
+					err("%s - Error ctrl_read failed\n", __func__);
+					rc = -EINVAL;
+					break;
+				}
+			}
+			break;
+		default:
+			rc = -EINVAL;
+			break;
+		}
+	}
+	//--------------------------------------------------------------------
+	// cleanup
+	//--------------------------------------------------------------------
+
+	// remove physical to logical address mapping
+	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
+		iounmap(wpg_bbar);
+
+	free_hpc_access();
+
+	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
+	return rc;
+}
+
+/*----------------------------------------------------------------------
+* Name:    ibmphp_hpc_writeslot()
+*
+* Action: issue a WRITE command to HPC
+*---------------------------------------------------------------------*/
+int ibmphp_hpc_writeslot(struct slot *pslot, u8 cmd)
+{
+	void __iomem *wpg_bbar = NULL;
+	struct controller *ctlr_ptr;
+	u8 index, status;
+	int busindex;
+	u8 done;
+	int rc = 0;
+	int timeout;
+
+	debug_polling("%s - Entry pslot[%p] cmd[%x]\n", __func__, pslot, cmd);
+	if (pslot == NULL) {
+		rc = -EINVAL;
+		err("%s - Error Exit rc[%d]\n", __func__, rc);
+		return rc;
+	}
+
+	if ((cmd == HPC_BUS_33CONVMODE) || (cmd == HPC_BUS_66CONVMODE) ||
+		(cmd == HPC_BUS_66PCIXMODE) || (cmd == HPC_BUS_100PCIXMODE) ||
+		(cmd == HPC_BUS_133PCIXMODE)) {
+		busindex = ibmphp_get_bus_index(pslot->bus);
+		if (busindex < 0) {
+			rc = -EINVAL;
+			err("%s - Exit Error:invalid bus, rc[%d]\n", __func__, rc);
+			return rc;
+		} else
+			index = (u8) busindex;
+	} else
+		index = pslot->ctlr_index;
+
+	index = hpc_writecmdtoindex(cmd, index);
+
+	if (index == HPC_ERROR) {
+		rc = -EINVAL;
+		err("%s - Error Exit rc[%d]\n", __func__, rc);
+		return rc;
+	}
+
+	ctlr_ptr = pslot->ctrl;
+
+	get_hpc_access();
+
+	//--------------------------------------------------------------------
+	// map physical address to logical address
+	//--------------------------------------------------------------------
+	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4)) {
+		wpg_bbar = ioremap(ctlr_ptr->u.wpeg_ctlr.wpegbbar, WPG_I2C_IOREMAP_SIZE);
+
+		debug("%s - ctlr id[%x] physical[%lx] logical[%lx] i2c[%x]\n", __func__,
+		ctlr_ptr->ctlr_id, (ulong) (ctlr_ptr->u.wpeg_ctlr.wpegbbar), (ulong) wpg_bbar,
+		ctlr_ptr->u.wpeg_ctlr.i2c_addr);
+	}
+	//--------------------------------------------------------------------
+	// check controller status before writing
+	//--------------------------------------------------------------------
+	rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar, &status);
+	if (!rc) {
+
+		ctrl_write(ctlr_ptr, wpg_bbar, index, cmd);
+
+		//--------------------------------------------------------------------
+		// check controller is still not working on the command
+		//--------------------------------------------------------------------
+		timeout = CMD_COMPLETE_TOUT_SEC;
+		done = 0;
+		while (!done) {
+			rc = hpc_wait_ctlr_notworking(HPC_CTLR_WORKING_TOUT, ctlr_ptr, wpg_bbar,
+							&status);
+			if (!rc) {
+				if (NEEDTOCHECK_CMDSTATUS(cmd)) {
+					if (CTLR_FINISHED(status) == HPC_CTLR_FINISHED_YES)
+						done = 1;
+				} else
+					done = 1;
+			}
+			if (!done) {
+				msleep(1000);
+				if (timeout < 1) {
+					done = 1;
+					err("%s - Error command complete timeout\n", __func__);
+					rc = -EFAULT;
+				} else
+					timeout--;
+			}
+		}
+		ctlr_ptr->status = status;
+	}
+	// cleanup
+
+	// remove physical to logical address mapping
+	if ((ctlr_ptr->ctlr_type == 2) || (ctlr_ptr->ctlr_type == 4))
+		iounmap(wpg_bbar);
+	free_hpc_access();
+
+	debug_polling("%s - Exit rc[%d]\n", __func__, rc);
+	return rc;
+}
+
+/*----------------------------------------------------------------------
+* Name:    get_hpc_access()
+*
+* Action: make sure only one process can access HPC at one time
+*---------------------------------------------------------------------*/
+static void get_hpc_access(void)
+{
+	mutex_lock(&sem_hpcaccess);
+}
+
+/*----------------------------------------------------------------------
+* Name:    free_hpc_access()
+*---------------------------------------------------------------------*/
+void free_hpc_access(void)
+{
+	mutex_unlock(&sem_hpcaccess);
+}
+
+/*----------------------------------------------------------------------
+* Name:    ibmphp_lock_operations()
+*
+* Action: make sure only one process can change the data structure
+*---------------------------------------------------------------------*/
+void ibmphp_lock_operations(void)
+{
+	mutex_lock(&operations_mutex);
+	to_debug = 1;
+}
+
+/*----------------------------------------------------------------------
+* Name:    ibmphp_unlock_operations()
+*---------------------------------------------------------------------*/
+void ibmphp_unlock_operations(void)
+{
+	debug("%s - Entry\n", __func__);
+	mutex_unlock(&operations_mutex);
+	to_debug = 0;
+	debug("%s - Exit\n", __func__);
+}
+
+/*----------------------------------------------------------------------
+* Name:    poll_hpc()
+*---------------------------------------------------------------------*/
+#define POLL_LATCH_REGISTER	0
+#define POLL_SLOTS		1
+#define POLL_SLEEP		2
+static int poll_hpc(void *data)
+{
+	struct slot myslot;
+	struct slot *pslot = NULL;
+	int rc;
+	int poll_state = POLL_LATCH_REGISTER;
+	u8 oldlatchlow = 0x00;
+	u8 curlatchlow = 0x00;
+	int poll_count = 0;
+	u8 ctrl_count = 0x00;
+
+	debug("%s - Entry\n", __func__);
+
+	while (!kthread_should_stop()) {
+		/* try to get the lock to do some kind of hardware access */
+		mutex_lock(&operations_mutex);
+
+		switch (poll_state) {
+		case POLL_LATCH_REGISTER:
+			oldlatchlow = curlatchlow;
+			ctrl_count = 0x00;
+			list_for_each_entry(pslot, &ibmphp_slot_head,
+					    ibm_slot_list) {
+				if (ctrl_count >= ibmphp_get_total_controllers())
+					break;
+				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
+					ctrl_count++;
+					if (READ_SLOT_LATCH(pslot->ctrl)) {
+						rc = ibmphp_hpc_readslot(pslot,
+									  READ_SLOTLATCHLOWREG,
+									  &curlatchlow);
+						if (oldlatchlow != curlatchlow)
+							process_changeinlatch(oldlatchlow,
+									       curlatchlow,
+									       pslot->ctrl);
+					}
+				}
+			}
+			++poll_count;
+			poll_state = POLL_SLEEP;
+			break;
+		case POLL_SLOTS:
+			list_for_each_entry(pslot, &ibmphp_slot_head,
+					    ibm_slot_list) {
+				// make a copy of the old status
+				memcpy((void *) &myslot, (void *) pslot,
+					sizeof(struct slot));
+				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
+				if ((myslot.status != pslot->status)
+				    || (myslot.ext_status != pslot->ext_status))
+					process_changeinstatus(pslot, &myslot);
+			}
+			ctrl_count = 0x00;
+			list_for_each_entry(pslot, &ibmphp_slot_head,
+					    ibm_slot_list) {
+				if (ctrl_count >= ibmphp_get_total_controllers())
+					break;
+				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
+					ctrl_count++;
+					if (READ_SLOT_LATCH(pslot->ctrl))
+						rc = ibmphp_hpc_readslot(pslot,
+									  READ_SLOTLATCHLOWREG,
+									  &curlatchlow);
+				}
+			}
+			++poll_count;
+			poll_state = POLL_SLEEP;
+			break;
+		case POLL_SLEEP:
+			/* don't sleep with a lock on the hardware */
+			mutex_unlock(&operations_mutex);
+			msleep(POLL_INTERVAL_SEC * 1000);
+
+			if (kthread_should_stop())
+				goto out_sleep;
+
+			mutex_lock(&operations_mutex);
+
+			if (poll_count >= POLL_LATCH_CNT) {
+				poll_count = 0;
+				poll_state = POLL_SLOTS;
+			} else
+				poll_state = POLL_LATCH_REGISTER;
+			break;
+		}
+		/* give up the hardware semaphore */
+		mutex_unlock(&operations_mutex);
+		/* sleep for a short time just for good measure */
+out_sleep:
+		msleep(100);
+	}
+	complete(&exit_complete);
+	debug("%s - Exit\n", __func__);
+	return 0;
+}
+
+
+/*----------------------------------------------------------------------
+* Name:    process_changeinstatus
+*
+* Action:  compare old and new slot status, process the change in status
+*
+* Input:   pointer to slot struct, old slot struct
+*
+* Return   0 or error codes
+* Value:
+*
+* Side
+* Effects: None.
+*
+* Notes:
+*---------------------------------------------------------------------*/
+static int process_changeinstatus(struct slot *pslot, struct slot *poldslot)
+{
+	u8 status;
+	int rc = 0;
+	u8 disable = 0;
+	u8 update = 0;
+
+	debug("process_changeinstatus - Entry pslot[%p], poldslot[%p]\n", pslot, poldslot);
+
+	// bit 0 - HPC_SLOT_POWER
+	if ((pslot->status & 0x01) != (poldslot->status & 0x01))
+		update = 1;
+
+	// bit 1 - HPC_SLOT_CONNECT
+	// ignore
+
+	// bit 2 - HPC_SLOT_ATTN
+	if ((pslot->status & 0x04) != (poldslot->status & 0x04))
+		update = 1;
+
+	// bit 3 - HPC_SLOT_PRSNT2
+	// bit 4 - HPC_SLOT_PRSNT1
+	if (((pslot->status & 0x08) != (poldslot->status & 0x08))
+		|| ((pslot->status & 0x10) != (poldslot->status & 0x10)))
+		update = 1;
+
+	// bit 5 - HPC_SLOT_PWRGD
+	if ((pslot->status & 0x20) != (poldslot->status & 0x20))
+		// OFF -> ON: ignore, ON -> OFF: disable slot
+		if ((poldslot->status & 0x20) && (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status)))
+			disable = 1;
+
+	// bit 6 - HPC_SLOT_BUS_SPEED
+	// ignore
+
+	// bit 7 - HPC_SLOT_LATCH
+	if ((pslot->status & 0x80) != (poldslot->status & 0x80)) {
+		update = 1;
+		// OPEN -> CLOSE
+		if (pslot->status & 0x80) {
+			if (SLOT_PWRGD(pslot->status)) {
+				// power goes on and off after closing latch
+				// check again to make sure power is still ON
+				msleep(1000);
+				rc = ibmphp_hpc_readslot(pslot, READ_SLOTSTATUS, &status);
+				if (SLOT_PWRGD(status))
+					update = 1;
+				else	// overwrite power in pslot to OFF
+					pslot->status &= ~HPC_SLOT_POWER;
+			}
+		}
+		// CLOSE -> OPEN
+		else if ((SLOT_PWRGD(poldslot->status) == HPC_SLOT_PWRGD_GOOD)
+			&& (SLOT_CONNECT(poldslot->status) == HPC_SLOT_CONNECTED) && (SLOT_PRESENT(poldslot->status))) {
+			disable = 1;
+		}
+		// else - ignore
+	}
+	// bit 4 - HPC_SLOT_BLINK_ATTN
+	if ((pslot->ext_status & 0x08) != (poldslot->ext_status & 0x08))
+		update = 1;
+
+	if (disable) {
+		debug("process_changeinstatus - disable slot\n");
+		pslot->flag = 0;
+		rc = ibmphp_do_disable_slot(pslot);
+	}
+
+	if (update || disable)
+		ibmphp_update_slot_info(pslot);
+
+	debug("%s - Exit rc[%d] disable[%x] update[%x]\n", __func__, rc, disable, update);
+
+	return rc;
+}
+
+/*----------------------------------------------------------------------
+* Name:    process_changeinlatch
+*
+* Action:  compare old and new latch reg status, process the change
+*
+* Input:   old and current latch register status
+*
+* Return   0 or error codes
+* Value:
+*---------------------------------------------------------------------*/
+static int process_changeinlatch(u8 old, u8 new, struct controller *ctrl)
+{
+	struct slot myslot, *pslot;
+	u8 i;
+	u8 mask;
+	int rc = 0;
+
+	debug("%s - Entry old[%x], new[%x]\n", __func__, old, new);
+	// bit 0 reserved, 0 is LSB, check bit 1-6 for 6 slots
+
+	for (i = ctrl->starting_slot_num; i <= ctrl->ending_slot_num; i++) {
+		mask = 0x01 << i;
+		if ((mask & old) != (mask & new)) {
+			pslot = ibmphp_get_slot_from_physical_num(i);
+			if (pslot) {
+				memcpy((void *) &myslot, (void *) pslot, sizeof(struct slot));
+				rc = ibmphp_hpc_readslot(pslot, READ_ALLSTAT, NULL);
+				debug("%s - call process_changeinstatus for slot[%d]\n", __func__, i);
+				process_changeinstatus(pslot, &myslot);
+			} else {
+				rc = -EINVAL;
+				err("%s - Error bad pointer for slot[%d]\n", __func__, i);
+			}
+		}
+	}
+	debug("%s - Exit rc[%d]\n", __func__, rc);
+	return rc;
+}
+
+/*----------------------------------------------------------------------
+* Name:    ibmphp_hpc_start_poll_thread
+*
+* Action:  start polling thread
+*---------------------------------------------------------------------*/
+int __init ibmphp_hpc_start_poll_thread(void)
+{
+	debug("%s - Entry\n", __func__);
+
+	ibmphp_poll_thread = kthread_run(poll_hpc, NULL, "hpc_poll");
+	if (IS_ERR(ibmphp_poll_thread)) {
+		err("%s - Error, thread not started\n", __func__);
+		return PTR_ERR(ibmphp_poll_thread);
+	}
+	return 0;
+}
+
+/*----------------------------------------------------------------------
+* Name:    ibmphp_hpc_stop_poll_thread
+*
+* Action:  stop polling thread and cleanup
+*---------------------------------------------------------------------*/
+void __exit ibmphp_hpc_stop_poll_thread(void)
+{
+	debug("%s - Entry\n", __func__);
+
+	kthread_stop(ibmphp_poll_thread);
+	debug("before locking operations\n");
+	ibmphp_lock_operations();
+	debug("after locking operations\n");
+
+	// wait for poll thread to exit
+	debug("before exit_complete down\n");
+	wait_for_completion(&exit_complete);
+	debug("after exit_completion down\n");
+
+	// cleanup
+	debug("before free_hpc_access\n");
+	free_hpc_access();
+	debug("after free_hpc_access\n");
+	ibmphp_unlock_operations();
+	debug("after unlock operations\n");
+
+	debug("%s - Exit\n", __func__);
+}
+
+/*----------------------------------------------------------------------
+* Name:    hpc_wait_ctlr_notworking
+*
+* Action:  wait until the controller is in a not working state
+*
+* Return   0, HPC_ERROR
+* Value:
+*---------------------------------------------------------------------*/
+static int hpc_wait_ctlr_notworking(int timeout, struct controller *ctlr_ptr, void __iomem *wpg_bbar,
+				    u8 *pstatus)
+{
+	int rc = 0;
+	u8 done = 0;
+
+	debug_polling("hpc_wait_ctlr_notworking - Entry timeout[%d]\n", timeout);
+
+	while (!done) {
+		*pstatus = ctrl_read(ctlr_ptr, wpg_bbar, WPG_CTLR_INDEX);
+		if (*pstatus == HPC_ERROR) {
+			rc = HPC_ERROR;
+			done = 1;
+		}
+		if (CTLR_WORKING(*pstatus) == HPC_CTLR_WORKING_NO)
+			done = 1;
+		if (!done) {
+			msleep(1000);
+			if (timeout < 1) {
+				done = 1;
+				err("HPCreadslot - Error ctlr timeout\n");
+				rc = HPC_ERROR;
+			} else
+				timeout--;
+		}
+	}
+	debug_polling("hpc_wait_ctlr_notworking - Exit rc[%x] status[%x]\n", rc, *pstatus);
+	return rc;
+}