arch/mips/pmc-sierra/msp71xx/msp_hwbutton.c

   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 #ifdef CONFIG_PMCTWILED
  36 #include <msp_led_macros.h>
  37 #endif
  38
  39 /* For hwbutton_interrupt->initial_state */
  40 #define HWBUTTON_HI     0x1
  41 #define HWBUTTON_LO     0x2
  42
  43 /*
  44  * This struct describes a hardware button
  45  */
  46 struct hwbutton_interrupt {
  47         char *name;                     /* Name of button */
  48         int irq;                        /* Actual LINUX IRQ */
  49         int eirq;                       /* Extended IRQ number (0-7) */
  50         int initial_state;              /* The "normal" state of the switch */
  51         void (*handle_hi)(void *);      /* Handler: switch input has gone HI */
  52         void (*handle_lo)(void *);      /* Handler: switch input has gone LO */
  53         void *data;                     /* Optional data to pass to handler */
  54 };
  55
  56 #ifdef CONFIG_PMC_MSP7120_GW
  57 extern void msp_restart(char *);
  58
  59 static void softreset_push(void *data)
  60 {
  61         printk(KERN_WARNING "SOFTRESET switch was pushed\n");
  62
  63         /*
  64          * In the future you could move this to the release handler,
  65          * timing the difference between the 'push' and 'release', and only
  66          * doing this ungraceful restart if the button has been down for
  67          * a certain amount of time; otherwise doing a graceful restart.
  68          */
  69
  70         msp_restart(NULL);
  71 }
  72
  73 static void softreset_release(void *data)
  74 {
  75         printk(KERN_WARNING "SOFTRESET switch was released\n");
  76
  77         /* Do nothing */
  78 }
  79
  80 static void standby_on(void *data)
  81 {
  82         printk(KERN_WARNING "STANDBY switch was set to ON (not implemented)\n");
  83
  84         /* TODO: Put board in standby mode */
  85 #ifdef CONFIG_PMCTWILED
  86         msp_led_turn_off(MSP_LED_PWRSTANDBY_GREEN);
  87         msp_led_turn_on(MSP_LED_PWRSTANDBY_RED);
  88 #endif
  89 }
  90
  91 static void standby_off(void *data)
  92 {
  93         printk(KERN_WARNING
  94                 "STANDBY switch was set to OFF (not implemented)\n");
  95
  96         /* TODO: Take out of standby mode */
  97 #ifdef CONFIG_PMCTWILED
  98         msp_led_turn_on(MSP_LED_PWRSTANDBY_GREEN);
  99         msp_led_turn_off(MSP_LED_PWRSTANDBY_RED);
 100 #endif
 101 }
 102
 103 static struct hwbutton_interrupt softreset_sw = {
 104         .name = "Softreset button",
 105         .irq = MSP_INT_EXT0,
 106         .eirq = 0,
 107         .initial_state = HWBUTTON_HI,
 108         .handle_hi = softreset_release,
 109         .handle_lo = softreset_push,
 110         .data = NULL,
 111 };
 112
 113 static struct hwbutton_interrupt standby_sw = {
 114         .name = "Standby switch",
 115         .irq = MSP_INT_EXT1,
 116         .eirq = 1,
 117         .initial_state = HWBUTTON_HI,
 118         .handle_hi = standby_off,
 119         .handle_lo = standby_on,
 120         .data = NULL,
 121 };
 122 #endif /* CONFIG_PMC_MSP7120_GW */
 123
 124 static irqreturn_t hwbutton_handler(int irq, void *data)
 125 {
 126         struct hwbutton_interrupt *hirq = data;
 127         unsigned long cic_ext = *CIC_EXT_CFG_REG;
 128
 129         if (irq != hirq->irq)
 130                 return IRQ_NONE;
 131
 132         if (CIC_EXT_IS_ACTIVE_HI(cic_ext, hirq->eirq)) {
 133                 /* Interrupt: pin is now HI */
 134                 CIC_EXT_SET_ACTIVE_LO(cic_ext, hirq->eirq);
 135                 hirq->handle_hi(hirq->data);
 136         } else {
 137                 /* Interrupt: pin is now LO */
 138                 CIC_EXT_SET_ACTIVE_HI(cic_ext, hirq->eirq);
 139                 hirq->handle_lo(hirq->data);
 140         }
 141
 142         /*
 143          * Invert the POLARITY of this level interrupt to ack the interrupt
 144          * Thus next state change will invoke the opposite message
 145          */
 146         *CIC_EXT_CFG_REG = cic_ext;
 147
 148         return IRQ_HANDLED;
 149 }
 150
 151 static int msp_hwbutton_register(struct hwbutton_interrupt *hirq)
 152 {
 153         unsigned long cic_ext;
 154
 155         if (hirq->handle_hi == NULL || hirq->handle_lo == NULL)
 156                 return -EINVAL;
 157
 158         cic_ext = *CIC_EXT_CFG_REG;
 159         CIC_EXT_SET_TRIGGER_LEVEL(cic_ext, hirq->eirq);
 160         if (hirq->initial_state == HWBUTTON_HI)
 161                 CIC_EXT_SET_ACTIVE_LO(cic_ext, hirq->eirq);
 162         else
 163                 CIC_EXT_SET_ACTIVE_HI(cic_ext, hirq->eirq);
 164         *CIC_EXT_CFG_REG = cic_ext;
 165
 166         return request_irq(hirq->irq, hwbutton_handler, IRQF_DISABLED,
 167                                 hirq->name, (void *)hirq);
 168 }
 169
 170 static int __init msp_hwbutton_setup(void)
 171 {
 172 #ifdef CONFIG_PMC_MSP7120_GW
 173         msp_hwbutton_register(&softreset_sw);
 174         msp_hwbutton_register(&standby_sw);
 175 #endif
 176         return 0;
 177 }
 178
 179 subsys_initcall(msp_hwbutton_setup);