pciehp_hpc.c

audio driver for hotplug pci on linux 2.6.27

/*
 * PCI Express PCI Hot Plug Driver
 *
 * Copyright (C) 1995,2001 Compaq Computer Corporation
 * Copyright (C) 2001 Greg Kroah-Hartman ([e-mail])
 * Copyright (C) 2001 IBM Corp.
 * Copyright (C) 2003-2004 Intel Corporation
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <[e-mail]>,<[e-mail]>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/signal.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/time.h>

#include "../pci.h"
#include "pciehp.h"

static atomic_t pciehp_num_controllers = ATOMIC_INIT(0);

struct ctrl_reg {
	u8 cap_id;
	u8 nxt_ptr;
	u16 cap_reg;
	u32 dev_cap;
	u16 dev_ctrl;
	u16 dev_status;
	u32 lnk_cap;
	u16 lnk_ctrl;
	u16 lnk_status;
	u32 slot_cap;
	u16 slot_ctrl;
	u16 slot_status;
	u16 root_ctrl;
	u16 rsvp;
	u32 root_status;
} __attribute__ ((packed));

/* offsets to the controller registers based on the above structure layout */
enum ctrl_offsets {
	PCIECAPID	=	offsetof(struct ctrl_reg, cap_id),
	NXTCAPPTR	=	offsetof(struct ctrl_reg, nxt_ptr),
	CAPREG		=	offsetof(struct ctrl_reg, cap_reg),
	DEVCAP		=	offsetof(struct ctrl_reg, dev_cap),
	DEVCTRL		=	offsetof(struct ctrl_reg, dev_ctrl),
	DEVSTATUS	=	offsetof(struct ctrl_reg, dev_status),
	LNKCAP		=	offsetof(struct ctrl_reg, lnk_cap),
	LNKCTRL		=	offsetof(struct ctrl_reg, lnk_ctrl),
	LNKSTATUS	=	offsetof(struct ctrl_reg, lnk_status),
	SLOTCAP		=	offsetof(struct ctrl_reg, slot_cap),
	SLOTCTRL	=	offsetof(struct ctrl_reg, slot_ctrl),
	SLOTSTATUS	=	offsetof(struct ctrl_reg, slot_status),
	ROOTCTRL	=	offsetof(struct ctrl_reg, root_ctrl),
	ROOTSTATUS	=	offsetof(struct ctrl_reg, root_status),
};

static inline int pciehp_readw(struct controller *ctrl, int reg, u16 *value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_read_config_word(dev, ctrl->cap_base + reg, value);
}

static inline int pciehp_readl(struct controller *ctrl, int reg, u32 *value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_read_config_dword(dev, ctrl->cap_base + reg, value);
}

static inline int pciehp_writew(struct controller *ctrl, int reg, u16 value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_write_config_word(dev, ctrl->cap_base + reg, value);
}

static inline int pciehp_writel(struct controller *ctrl, int reg, u32 value)
{
	struct pci_dev *dev = ctrl->pci_dev;
	return pci_write_config_dword(dev, ctrl->cap_base + reg, value);
}

/* Field definitions in PCI Express Capabilities Register */
#define CAP_VER			0x000F
#define DEV_PORT_TYPE		0x00F0
#define SLOT_IMPL		0x0100
#define MSG_NUM			0x3E00

/* Device or Port Type */
#define NAT_ENDPT		0x00
#define LEG_ENDPT		0x01
#define ROOT_PORT		0x04
#define UP_STREAM		0x05
#define	DN_STREAM		0x06
#define PCIE_PCI_BRDG		0x07
#define PCI_PCIE_BRDG		0x10

/* Field definitions in Device Capabilities Register */
#define DATTN_BUTTN_PRSN	0x1000
#define DATTN_LED_PRSN		0x2000
#define DPWR_LED_PRSN		0x4000

/* Field definitions in Link Capabilities Register */
#define MAX_LNK_SPEED		0x000F
#define MAX_LNK_WIDTH		0x03F0

/* Link Width Encoding */
#define LNK_X1		0x01
#define LNK_X2		0x02
#define LNK_X4		0x04
#define LNK_X8		0x08
#define LNK_X12		0x0C
#define LNK_X16		0x10
#define LNK_X32		0x20

/*Field definitions of Link Status Register */
#define LNK_SPEED	0x000F
#define NEG_LINK_WD	0x03F0
#define LNK_TRN_ERR	0x0400
#define	LNK_TRN		0x0800
#define SLOT_CLK_CONF	0x1000

/* Field definitions in Slot Capabilities Register */
#define ATTN_BUTTN_PRSN	0x00000001
#define	PWR_CTRL_PRSN	0x00000002
#define MRL_SENS_PRSN	0x00000004
#define ATTN_LED_PRSN	0x00000008
#define PWR_LED_PRSN	0x00000010
#define HP_SUPR_RM_SUP	0x00000020
#define HP_CAP		0x00000040
#define SLOT_PWR_VALUE	0x000003F8
#define SLOT_PWR_LIMIT	0x00000C00
#define PSN		0xFFF80000	/* PSN: Physical Slot Number */

/* Field definitions in Slot Control Register */
#define ATTN_BUTTN_ENABLE		0x0001
#define PWR_FAULT_DETECT_ENABLE		0x0002
#define MRL_DETECT_ENABLE		0x0004
#define PRSN_DETECT_ENABLE		0x0008
#define CMD_CMPL_INTR_ENABLE		0x0010
#define HP_INTR_ENABLE			0x0020
#define ATTN_LED_CTRL			0x00C0
#define PWR_LED_CTRL			0x0300
#define PWR_CTRL			0x0400
#define EMI_CTRL			0x0800

/* Attention indicator and Power indicator states */
#define LED_ON		0x01
#define LED_BLINK	0x10
#define LED_OFF		0x11

/* Power Control Command */
#define POWER_ON	0
#define POWER_OFF	0x0400

/* EMI Status defines */
#define EMI_DISENGAGED	0
#define EMI_ENGAGED	1

/* Field definitions in Slot Status Register */
#define ATTN_BUTTN_PRESSED	0x0001
#define PWR_FAULT_DETECTED	0x0002
#define MRL_SENS_CHANGED	0x0004
#define PRSN_DETECT_CHANGED	0x0008
#define CMD_COMPLETED		0x0010
#define MRL_STATE		0x0020
#define PRSN_STATE		0x0040
#define EMI_STATE		0x0080
#define EMI_STATUS_BIT		7

static irqreturn_t pcie_isr(int irq, void *dev_id);
static void start_int_poll_timer(struct controller *ctrl, int sec);

/* This is the interrupt polling timeout function. */
static void int_poll_timeout(unsigned long data)
{
	struct controller *ctrl = (struct controller *)data;

	/* Poll for interrupt events.  regs == NULL => polling */
	pcie_isr(0, ctrl);

	init_timer(&ctrl->poll_timer);
	if (!pciehp_poll_time)
		pciehp_poll_time = 2; /* default polling interval is 2 sec */

	start_int_poll_timer(ctrl, pciehp_poll_time);
}

/* This function starts the interrupt polling timer. */
static void start_int_poll_timer(struct controller *ctrl, int sec)
{
	/* Clamp to sane value */
	if ((sec <= 0) || (sec > 60))
        	sec = 2;

	ctrl->poll_timer.function = &int_poll_timeout;
	ctrl->poll_timer.data = (unsigned long)ctrl;
	ctrl->poll_timer.expires = jiffies + sec * HZ;
	add_timer(&ctrl->poll_timer);
}

static inline int pciehp_request_irq(struct controller *ctrl)
{
	int retval, irq = ctrl->pci_dev->irq;

	/* Install interrupt polling timer. Start with 10 sec delay */
	if (pciehp_poll_mode) {
		init_timer(&ctrl->poll_timer);
		start_int_poll_timer(ctrl, 10);
		return 0;
	}

	/* Installs the interrupt handler */
	retval = request_irq(irq, pcie_isr, IRQF_SHARED, MY_NAME, ctrl);
	if (retval)
		err("Cannot get irq %d for the hotplug controller\n", irq);
	return retval;
}

static inline void pciehp_free_irq(struct controller *ctrl)
{
	if (pciehp_poll_mode)
		del_timer_sync(&ctrl->poll_timer);
	else
		free_irq(ctrl->pci_dev->irq, ctrl);
}

static int pcie_poll_cmd(struct controller *ctrl)
{
	u16 slot_status;
	int timeout = 1000;

	if (!pciehp_readw(ctrl, SLOTSTATUS, &slot_status)) {
		if (slot_status & CMD_COMPLETED) {
			pciehp_writew(ctrl, SLOTSTATUS, CMD_COMPLETED);
			return 1;
		}
	}
	while (timeout > 0) {
		msleep(10);
		timeout -= 10;
		if (!pciehp_readw(ctrl, SLOTSTATUS, &slot_status)) {
			if (slot_status & CMD_COMPLETED) {
				pciehp_writew(ctrl, SLOTSTATUS, CMD_COMPLETED);
				return 1;
			}
		}
	}
	return 0;	/* timeout */
}

static void pcie_wait_cmd(struct controller *ctrl, int poll)
{
	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
	unsigned long timeout = msecs_to_jiffies(msecs);
	int rc;

	if (poll)
		rc = pcie_poll_cmd(ctrl);
	else
		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
	if (!rc)
		dbg("Command not completed in 1000 msec\n");
}

/**
 * pcie_write_cmd - Issue controller command
 * @ctrl: controller to which the command is issued
 * @cmd:  command value written to slot control register
 * @mask: bitmask of slot control register to be modified
 */
static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
{
	int retval = 0;
	u16 slot_status;
	u16 slot_ctrl;

	mutex_lock(&ctrl->ctrl_lock);

	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
	if (retval) {
		err("%s: Cannot read SLOTSTATUS register\n", __func__);
		goto out;
	}

	if (slot_status & CMD_COMPLETED) {
		if (!ctrl->no_cmd_complete) {
			/*
			 * After 1 sec and CMD_COMPLETED still not set, just
			 * proceed forward to issue the next command according
			 * to spec. Just print out the error message.
			 */
			dbg("%s: CMD_COMPLETED not clear after 1 sec.\n",
			    __func__);
		} else if (!NO_CMD_CMPL(ctrl)) {
			/*
			 * This controller semms to notify of command completed
			 * event even though it supports none of power
			 * controller, attention led, power led and EMI.
			 */
			dbg("%s: Unexpected CMD_COMPLETED. Need to wait for "
			    "command completed event.\n", __func__);
			ctrl->no_cmd_complete = 0;
		} else {
			dbg("%s: Unexpected CMD_COMPLETED. Maybe the "
			    "controller is broken.\n", __func__);
		}
	}

	retval = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);
	if (retval) {
		err("%s: Cannot read SLOTCTRL register\n", __func__);
		goto out;
	}

	slot_ctrl &= ~mask;
	slot_ctrl |= (cmd & mask);
	ctrl->cmd_busy = 1;
	smp_mb();
	retval = pciehp_writew(ctrl, SLOTCTRL, slot_ctrl);
	if (retval)
		err("%s: Cannot write to SLOTCTRL register\n", __func__);

	/*
	 * Wait for command completion.
	 */
	if (!retval && !ctrl->no_cmd_complete) {
		int poll = 0;
		/*
		 * if hotplug interrupt is not enabled or command
		 * completed interrupt is not enabled, we need to poll
		 * command completed event.
		 */
		if (!(slot_ctrl & HP_INTR_ENABLE) ||
		    !(slot_ctrl & CMD_CMPL_INTR_ENABLE))
			poll = 1;
                pcie_wait_cmd(ctrl, poll);
	}
 out:
	mutex_unlock(&ctrl->ctrl_lock);
	return retval;
}

static int hpc_check_lnk_status(struct controller *ctrl)
{
	u16 lnk_status;
	int retval = 0;

	retval = pciehp_readw(ctrl, LNKSTATUS, &lnk_status);
	if (retval) {
		err("%s: Cannot read LNKSTATUS register\n", __func__);
		return retval;
	}

	dbg("%s: lnk_status = %x\n", __func__, lnk_status);
	if ( (lnk_status & LNK_TRN) || (lnk_status & LNK_TRN_ERR) ||
		!(lnk_status & NEG_LINK_WD)) {
		err("%s : Link Training Error occurs \n", __func__);
		retval = -1;
		return retval;
	}

	return retval;
}

static int hpc_get_attention_status(struct slot *slot, u8 *status)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_ctrl;
	u8 atten_led_state;
	int retval = 0;

	retval = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);
	if (retval) {
		err("%s: Cannot read SLOTCTRL register\n", __func__);
		return retval;
	}

	dbg("%s: SLOTCTRL %x, value read %x\n",
	    __func__, ctrl->cap_base + SLOTCTRL, slot_ctrl);

	atten_led_state = (slot_ctrl & ATTN_LED_CTRL) >> 6;

	switch (atten_led_state) {
	case 0:
		*status = 0xFF;	/* Reserved */
		break;
	case 1:
		*status = 1;	/* On */
		break;
	case 2:
		*status = 2;	/* Blink */
		break;
	case 3:
		*status = 0;	/* Off */
		break;
	default:
		*status = 0xFF;
		break;
	}

	return 0;
}

static int hpc_get_power_status(struct slot *slot, u8 *status)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_ctrl;
	u8 pwr_state;
	int	retval = 0;

	retval = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl);
	if (retval) {
		err("%s: Cannot read SLOTCTRL register\n", __func__);
		return retval;
	}
	dbg("%s: SLOTCTRL %x value read %x\n",
	    __func__, ctrl->cap_base + SLOTCTRL, slot_ctrl);

	pwr_state = (slot_ctrl & PWR_CTRL) >> 10;

	switch (pwr_state) {
	case 0:
		*status = 1;
		break;
	case 1:
		*status = 0;
		break;
	default:
		*status = 0xFF;
		break;
	}

	return retval;
}

static int hpc_get_latch_status(struct slot *slot, u8 *status)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_status;
	int retval = 0;

	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
	if (retval) {
		err("%s: Cannot read SLOTSTATUS register\n", __func__);
		return retval;
	}

	*status = (((slot_status & MRL_STATE) >> 5) == 0) ? 0 : 1;

	return 0;
}

static int hpc_get_adapter_status(struct slot *slot, u8 *status)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_status;
	u8 card_state;
	int retval = 0;

	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
	if (retval) {
		err("%s: Cannot read SLOTSTATUS register\n", __func__);
		return retval;
	}
	card_state = (u8)((slot_status & PRSN_STATE) >> 6);
	*status = (card_state == 1) ? 1 : 0;

	return 0;
}

static int hpc_query_power_fault(struct slot *slot)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_status;
	u8 pwr_fault;
	int retval = 0;

	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
	if (retval) {
		err("%s: Cannot check for power fault\n", __func__);
		return retval;
	}
	pwr_fault = (u8)((slot_status & PWR_FAULT_DETECTED) >> 1);

	return pwr_fault;
}

static int hpc_get_emi_status(struct slot *slot, u8 *status)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_status;
	int retval = 0;

	retval = pciehp_readw(ctrl, SLOTSTATUS, &slot_status);
	if (retval) {
		err("%s : Cannot check EMI status\n", __func__);
		return retval;
	}
	*status = (slot_status & EMI_STATE) >> EMI_STATUS_BIT;

	return retval;
}

static int hpc_toggle_emi(struct slot *slot)
{
	u16 slot_cmd;
	u16 cmd_mask;
	int rc;

	slot_cmd = EMI_CTRL;
	cmd_mask = EMI_CTRL;
	rc = pcie_write_cmd(slot->ctrl, slot_cmd, cmd_mask);
	slot->last_emi_toggle = get_seconds();

	return rc;
}

static int hpc_set_attention_status(struct slot *slot, u8 value)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_cmd;
	u16 cmd_mask;
	int rc;

	cmd_mask = ATTN_LED_CTRL;
	switch (value) {
		case 0 :	/* turn off */
			slot_cmd = 0x00C0;
			break;
		case 1:		/* turn on */
			slot_cmd = 0x0040;
			break;
		case 2:		/* turn blink */
			slot_cmd = 0x0080;
			break;
		default:
			return -1;
	}
	rc = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
	dbg("%s: SLOTCTRL %x write cmd %x\n",
	    __func__, ctrl->cap_base + SLOTCTRL, slot_cmd);

	return rc;
}

static void hpc_set_green_led_on(struct slot *slot)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_cmd;
	u16 cmd_mask;

	slot_cmd = 0x0100;
	cmd_mask = PWR_LED_CTRL;
	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
	dbg("%s: SLOTCTRL %x write cmd %x\n",
	    __func__, ctrl->cap_base + SLOTCTRL, slot_cmd);
}

static void hpc_set_green_led_off(struct slot *slot)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_cmd;
	u16 cmd_mask;

	slot_cmd = 0x0300;
	cmd_mask = PWR_LED_CTRL;
	pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
	dbg("%s: SLOTCTRL %x write cmd %x\n",
	    __func__, ctrl->cap_base + SLOTCTRL, slot_cmd);
}

static void hpc_set_green_led_blink(struct slot *slot)
{
	struct controller *ctrl = slot->ctrl;
	u16 slot_cmd;