LXR linux/arch/mips/pmcs-msp71xx/msp

   1/*
   2 * Sets up interrupt handlers for various hardware switches which are
   3 * connected to interrupt lines.
   4 *
   5 * Copyright 2005-2207 PMC-Sierra, Inc.
   6 *
   7 *  This program is free software; you can redistribute  it and/or modify it
   8 *  under  the terms of  the GNU General  Public License as published by the
   9 *  Free Software Foundation;  either version 2 of the  License, or (at your
  10 *  option) any later version.
  11 *
  12 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  13 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  14 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  15 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  16 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  17 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  18 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  19 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  20 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  21 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  22 *
  23 *  You should have received a copy of the  GNU General Public License along
  24 *  with this program; if not, write  to the Free Software Foundation, Inc.,
  25 *  675 Mass Ave, Cambridge, MA 02139, USA.
  26 */
  27
  28#include <linux/kernel.h>
  29#include <linux/init.h>
  30#include <linux/interrupt.h>
  31
  32#include <msp_int.h>
  33#include <msp_regs.h>
  34#include <msp_regops.h>
  35
  36/* For hwbutton_interrupt->initial_state */
  37#define HWBUTTON_HI     0x1
  38#define HWBUTTON_LO     0x2
  39
  40/*
  41 * This struct describes a hardware button
  42 */
  43struct hwbutton_interrupt {
  44        char *name;                     /* Name of button */
  45        int irq;                        /* Actual LINUX IRQ */
  46        int eirq;                       /* Extended IRQ number (0-7) */
  47        int initial_state;              /* The "normal" state of the switch */
  48        void (*handle_hi)(void *);      /* Handler: switch input has gone HI */
  49        void (*handle_lo)(void *);      /* Handler: switch input has gone LO */
  50        void *data;                     /* Optional data to pass to handler */
  51};
  52
  53#ifdef CONFIG_PMC_MSP7120_GW
  54extern void msp_restart(char *);
  55
  56static void softreset_push(void *data)
  57{
  58        printk(KERN_WARNING "SOFTRESET switch was pushed\n");
  59
  60        /*
  61         * In the future you could move this to the release handler,
  62         * timing the difference between the 'push' and 'release', and only
  63         * doing this ungraceful restart if the button has been down for
  64         * a certain amount of time; otherwise doing a graceful restart.
  65         */
  66
  67        msp_restart(NULL);
  68}
  69
  70static void softreset_release(void *data)
  71{
  72        printk(KERN_WARNING "SOFTRESET switch was released\n");
  73
  74        /* Do nothing */
  75}
  76
  77static void standby_on(void *data)
  78{
  79        printk(KERN_WARNING "STANDBY switch was set to ON (not implemented)\n");
  80
  81        /* TODO: Put board in standby mode */
  82}
  83
  84static void standby_off(void *data)
  85{
  86        printk(KERN_WARNING
  87                "STANDBY switch was set to OFF (not implemented)\n");
  88
  89        /* TODO: Take out of standby mode */
  90}
  91
  92static struct hwbutton_interrupt softreset_sw = {
  93        .name = "Softreset button",
  94        .irq = MSP_INT_EXT0,
  95        .eirq = 0,
  96        .initial_state = HWBUTTON_HI,
  97        .handle_hi = softreset_release,
  98        .handle_lo = softreset_push,
  99        .data = NULL,
 100};
 101
 102static struct hwbutton_interrupt standby_sw = {
 103        .name = "Standby switch",
 104        .irq = MSP_INT_EXT1,
 105        .eirq = 1,
 106        .initial_state = HWBUTTON_HI,
 107        .handle_hi = standby_off,
 108        .handle_lo = standby_on,
 109        .data = NULL,
 110};
 111#endif /* CONFIG_PMC_MSP7120_GW */
 112
 113static irqreturn_t hwbutton_handler(int irq, void *data)
 114{
 115        struct hwbutton_interrupt *hirq = data;
 116        unsigned long cic_ext = *CIC_EXT_CFG_REG;
 117
 118        if (CIC_EXT_IS_ACTIVE_HI(cic_ext, hirq->eirq)) {
 119                /* Interrupt: pin is now HI */
 120                CIC_EXT_SET_ACTIVE_LO(cic_ext, hirq->eirq);
 121                hirq->handle_hi(hirq->data);
 122        } else {
 123                /* Interrupt: pin is now LO */
 124                CIC_EXT_SET_ACTIVE_HI(cic_ext, hirq->eirq);
 125                hirq->handle_lo(hirq->data);
 126        }
 127
 128        /*
 129         * Invert the POLARITY of this level interrupt to ack the interrupt
 130         * Thus next state change will invoke the opposite message
 131         */
 132        *CIC_EXT_CFG_REG = cic_ext;
 133
 134        return IRQ_HANDLED;
 135}
 136
 137static int msp_hwbutton_register(struct hwbutton_interrupt *hirq)
 138{
 139        unsigned long cic_ext;
 140
 141        if (hirq->handle_hi == NULL || hirq->handle_lo == NULL)
 142                return -EINVAL;
 143
 144        cic_ext = *CIC_EXT_CFG_REG;
 145        CIC_EXT_SET_TRIGGER_LEVEL(cic_ext, hirq->eirq);
 146        if (hirq->initial_state == HWBUTTON_HI)
 147                CIC_EXT_SET_ACTIVE_LO(cic_ext, hirq->eirq);
 148        else
 149                CIC_EXT_SET_ACTIVE_HI(cic_ext, hirq->eirq);
 150        *CIC_EXT_CFG_REG = cic_ext;
 151
 152        return request_irq(hirq->irq, hwbutton_handler, 0,
 153                           hirq->name, hirq);
 154}
 155
 156static int __init msp_hwbutton_setup(void)
 157{
 158#ifdef CONFIG_PMC_MSP7120_GW
 159        msp_hwbutton_register(&softreset_sw);
 160        msp_hwbutton_register(&standby_sw);
 161#endif
 162        return 0;
 163}
 164
 165subsys_initcall(msp_hwbutton_setup);
 166