arch/arm/mach-pxa/htcapache/htcapache-power.c

   1 /*
   2  * Support for power detection code on the HTC Apache phone.
   3  *
   4  * (c) Copyright 2006 Kevin O'Connor <kevin@koconnor.net>
   5  *
   6  * This file may be distributed under the terms of the GNU GPL license.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/interrupt.h> // request_irq
  11
  12 #include <asm/arch/htcapache-gpio.h>
  13
  14
  15 /****************************************************************
  16  * Plug in/out events
  17  ****************************************************************/
  18
  19 // Interrupt handler called when plugging/unplugging mini-usb port
  20 static irqreturn_t
  21 power_isr(int irq, void *dev_id, struct pt_regs *regs)
  22 {
  23         int haspower = !htcapache_egpio_isset(EGPIO_NR_HTCAPACHE_PWR_IN_PWR);
  24         int hashigh = !htcapache_egpio_isset(EGPIO_NR_HTCAPACHE_PWR_IN_HIGHPWR);
  25         if (haspower && !hashigh) {
  26                 // USB plug - activate usb transceiver.
  27                 htcapache_egpio_set(EGPIO_NR_HTCAPACHE_USB_PWR);
  28         } else {
  29                 htcapache_egpio_clear(EGPIO_NR_HTCAPACHE_USB_PWR);
  30         }
  31         printk("USB mini plug event (pwr=%d ac=%d)\n"
  32                , haspower, hashigh);
  33         return IRQ_HANDLED;
  34 }
  35
  36
  37 /****************************************************************
  38  * Setup
  39  ****************************************************************/
  40
  41 void
  42 htcapache_power_init(void)
  43 {
  44         int result;
  45
  46         // Setup plug interrupt
  47         result = request_irq(IRQ_EGPIO(EGPIO_NR_HTCAPACHE_PWR_IN_PWR)
  48                              , power_isr, SA_SAMPLE_RANDOM,
  49                              "usb_plug", NULL);
  50         if (result)
  51                 printk("unable to claim irq %d for usb plug event. Got %d\n"
  52                        , IRQ_EGPIO(EGPIO_NR_HTCAPACHE_PWR_IN_PWR), result);
  53
  54         // Run the interrupt handler to initialize.
  55         power_isr(0, NULL, NULL);
  56 }