/*
   * Device driver for the PMU on 68K-based Apple PowerBooks
   *
   * The VIA (versatile interface adapter) interfaces to the PMU,
   * a 6805 microprocessor core whose primary function is to control
   * battery charging and system power on the PowerBooks.
   * The PMU also controls the ADB (Apple Desktop Bus) which connects
   * to the keyboard and mouse, as well as the non-volatile RAM
   * and the RTC (real time clock) chip.
   *
   * Adapted for 68K PMU by Joshua M. Thompson
   *
   * Based largely on the PowerMac PMU code by Paul Mackerras and
   * Fabio Riccardi.
   *
   * Also based on the PMU driver from MkLinux by Apple Computer, Inc.
   * and the Open Software Foundation, Inc.
   */
  
  #include <stdarg.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/miscdevice.h>
  #include <linux/blkdev.h>
  #include <linux/pci.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  
  #include <linux/adb.h>
  #include <linux/pmu.h>
  #include <linux/cuda.h>
  
  #include <asm/macintosh.h>
  #include <asm/macints.h>
  #include <asm/mac_via.h>
  
  #include <asm/pgtable.h>
  #include <asm/irq.h>
  #include <asm/uaccess.h>
  
  /* Misc minor number allocated for /dev/pmu */
  #define PMU_MINOR	154
  
  /* VIA registers - spaced 0x200 bytes apart */
  #define RS		0x200		/* skip between registers */
  #define B		0		/* B-side data */
  #define A		RS		/* A-side data */
  #define DIRB		(2*RS)		/* B-side direction (1=output) */
  #define DIRA		(3*RS)		/* A-side direction (1=output) */
  #define T1CL		(4*RS)		/* Timer 1 ctr/latch (low 8 bits) */
  #define T1CH		(5*RS)		/* Timer 1 counter (high 8 bits) */
  #define T1LL		(6*RS)		/* Timer 1 latch (low 8 bits) */
  #define T1LH		(7*RS)		/* Timer 1 latch (high 8 bits) */
  #define T2CL		(8*RS)		/* Timer 2 ctr/latch (low 8 bits) */
  #define T2CH		(9*RS)		/* Timer 2 counter (high 8 bits) */
  #define SR		(10*RS)		/* Shift register */
  #define ACR		(11*RS)		/* Auxiliary control register */
  #define PCR		(12*RS)		/* Peripheral control register */
  #define IFR		(13*RS)		/* Interrupt flag register */
  #define IER		(14*RS)		/* Interrupt enable register */
  #define ANH		(15*RS)		/* A-side data, no handshake */
  
  /* Bits in B data register: both active low */
  #define TACK		0x02		/* Transfer acknowledge (input) */
  #define TREQ		0x04		/* Transfer request (output) */
  
  /* Bits in ACR */
  #define SR_CTRL		0x1c		/* Shift register control bits */
  #define SR_EXT		0x0c		/* Shift on external clock */
  #define SR_OUT		0x10		/* Shift out if 1 */
  
  /* Bits in IFR and IER */
  #define SR_INT		0x04		/* Shift register full/empty */
  #define CB1_INT		0x10		/* transition on CB1 input */
  
  static enum pmu_state {
  	idle,
  	sending,
  	intack,
  	reading,
  	reading_intr,
  } pmu_state;
  
  static struct adb_request *current_req;
  static struct adb_request *last_req;
  static struct adb_request *req_awaiting_reply;
  static unsigned char interrupt_data[32];
  static unsigned char *reply_ptr;
  static int data_index;
  static int data_len;
  static int adb_int_pending;
  static int pmu_adb_flags;
  static int adb_dev_map;
  static struct adb_request bright_req_1, bright_req_2, bright_req_3;
  static int pmu_kind = PMU_UNKNOWN;
  static int pmu_fully_inited;
  
  int asleep;
  
  static int pmu_probe(void);
  static int pmu_init(void);
  static void pmu_start(void);
  static irqreturn_t pmu_interrupt(int irq, void *arg);
  static int pmu_send_request(struct adb_request *req, int sync);
  static int pmu_autopoll(int devs);
  void pmu_poll(void);
  static int pmu_reset_bus(void);
  
  static void pmu_start(void);
  static void send_byte(int x);
  static void recv_byte(void);
  static void pmu_done(struct adb_request *req);
  static void pmu_handle_data(unsigned char *data, int len);
  static void set_volume(int level);
  static void pmu_enable_backlight(int on);
  static void pmu_set_brightness(int level);
  
  struct adb_driver via_pmu_driver = {
  	"68K PMU",
  	pmu_probe,
  	pmu_init,
  	pmu_send_request,
  	pmu_autopoll,
  	pmu_poll,
  	pmu_reset_bus
  };
  
  /*
   * This table indicates for each PMU opcode:
   * - the number of data bytes to be sent with the command, or -1
   *   if a length byte should be sent,
   * - the number of response bytes which the PMU will return, or
   *   -1 if it will send a length byte.
   */
  static s8 pmu_data_len[256][2] = {
  /*	   0	   1	   2	   3	   4	   5	   6	   7  */
  /*00*/	{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*08*/	{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},
  /*10*/	{ 1, 0},{ 1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*18*/	{ 0, 1},{ 0, 1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{ 0, 0},
  /*20*/	{-1, 0},{ 0, 0},{ 2, 0},{ 1, 0},{ 1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*28*/	{ 0,-1},{ 0,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{ 0,-1},
  /*30*/	{ 4, 0},{20, 0},{-1, 0},{ 3, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*38*/	{ 0, 4},{ 0,20},{ 2,-1},{ 2, 1},{ 3,-1},{-1,-1},{-1,-1},{ 4, 0},
  /*40*/	{ 1, 0},{ 1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*48*/	{ 0, 1},{ 0, 1},{-1,-1},{ 1, 0},{ 1, 0},{-1,-1},{-1,-1},{-1,-1},
  /*50*/	{ 1, 0},{ 0, 0},{ 2, 0},{ 2, 0},{-1, 0},{ 1, 0},{ 3, 0},{ 1, 0},
  /*58*/	{ 0, 1},{ 1, 0},{ 0, 2},{ 0, 2},{ 0,-1},{-1,-1},{-1,-1},{-1,-1},
  /*60*/	{ 2, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*68*/	{ 0, 3},{ 0, 3},{ 0, 2},{ 0, 8},{ 0,-1},{ 0,-1},{-1,-1},{-1,-1},
  /*70*/	{ 1, 0},{ 1, 0},{ 1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*78*/	{ 0,-1},{ 0,-1},{-1,-1},{-1,-1},{-1,-1},{ 5, 1},{ 4, 1},{ 4, 1},
  /*80*/	{ 4, 0},{-1, 0},{ 0, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*88*/	{ 0, 5},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},
  /*90*/	{ 1, 0},{ 2, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*98*/	{ 0, 1},{ 0, 1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},
  /*a0*/	{ 2, 0},{ 2, 0},{ 2, 0},{ 4, 0},{-1, 0},{ 0, 0},{-1, 0},{-1, 0},
  /*a8*/	{ 1, 1},{ 1, 0},{ 3, 0},{ 2, 0},{-1,-1},{-1,-1},{-1,-1},{-1,-1},
  /*b0*/	{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*b8*/	{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},
  /*c0*/	{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*c8*/	{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},
  /*d0*/	{ 0, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*d8*/	{ 1, 1},{ 1, 1},{-1,-1},{-1,-1},{ 0, 1},{ 0,-1},{-1,-1},{-1,-1},
  /*e0*/	{-1, 0},{ 4, 0},{ 0, 1},{-1, 0},{-1, 0},{ 4, 0},{-1, 0},{-1, 0},
  /*e8*/	{ 3,-1},{-1,-1},{ 0, 1},{-1,-1},{ 0,-1},{-1,-1},{-1,-1},{ 0, 0},
  /*f0*/	{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},{-1, 0},
  /*f8*/	{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},{-1,-1},
  };
  
  int pmu_probe(void)
  {
  	if (macintosh_config->adb_type == MAC_ADB_PB1) {
  		pmu_kind = PMU_68K_V1;
  	} else if (macintosh_config->adb_type == MAC_ADB_PB2) {
  		pmu_kind = PMU_68K_V2;
  	} else {
  		return -ENODEV;
  	}
  
  	pmu_state = idle;
  
  	return 0;
  }
  
  static int 
  pmu_init(void)
  {
  	int timeout;
  	volatile struct adb_request req;
  
  	via2[B] |= TREQ;				/* negate TREQ */
  	via2[DIRB] = (via2[DIRB] | TREQ) & ~TACK;	/* TACK in, TREQ out */
  
  	pmu_request((struct adb_request *) &req, NULL, 2, PMU_SET_INTR_MASK, PMU_INT_ADB);
  	timeout =  100000;
  	while (!req.complete) {
  		if (--timeout < 0) {
  			printk(KERN_ERR "pmu_init: no response from PMU
  ");
  			return -EAGAIN;
  		}
  		udelay(10);
  		pmu_poll();
  	}
  
  	/* ack all pending interrupts */
  	timeout = 100000;
  	interrupt_data[0] = 1;
  	while (interrupt_data[0] || pmu_state != idle) {
  		if (--timeout < 0) {
  			printk(KERN_ERR "pmu_init: timed out acking intrs
  ");
  			return -EAGAIN;
  		}
  		if (pmu_state == idle) {
  			adb_int_pending = 1;
  			pmu_interrupt(0, NULL);
  		}
  		pmu_poll();
  		udelay(10);
  	}
  
  	pmu_request((struct adb_request *) &req, NULL, 2, PMU_SET_INTR_MASK,
  			PMU_INT_ADB_AUTO|PMU_INT_SNDBRT|PMU_INT_ADB);
  	timeout =  100000;
  	while (!req.complete) {
  		if (--timeout < 0) {
  			printk(KERN_ERR "pmu_init: no response from PMU
  ");
  			return -EAGAIN;
  		}
  		udelay(10);
  		pmu_poll();
  	}
  
  	bright_req_1.complete = 1;
  	bright_req_2.complete = 1;
  	bright_req_3.complete = 1;
  
  	if (request_irq(IRQ_MAC_ADB_SR, pmu_interrupt, 0, "pmu-shift",
  			pmu_interrupt)) {
  		printk(KERN_ERR "pmu_init: can't get irq %d
  ",
  			IRQ_MAC_ADB_SR);
  		return -EAGAIN;
  	}
  	if (request_irq(IRQ_MAC_ADB_CL, pmu_interrupt, 0, "pmu-clock",
  			pmu_interrupt)) {
  		printk(KERN_ERR "pmu_init: can't get irq %d
  ",
  			IRQ_MAC_ADB_CL);
  		free_irq(IRQ_MAC_ADB_SR, pmu_interrupt);
  		return -EAGAIN;
  	}
  
  	pmu_fully_inited = 1;
  	
  	/* Enable backlight */
  	pmu_enable_backlight(1);
  
  	printk("adb: PMU 68K driver v0.5 for Unified ADB.
  ");
  
  	return 0;
  }
  
  int
  pmu_get_model(void)
  {
  	return pmu_kind;
  }
  
  /* Send an ADB command */
  static int 
  pmu_send_request(struct adb_request *req, int sync)
  {
      int i, ret;
  
      if (!pmu_fully_inited)
      {
   	req->complete = 1;
     	return -ENXIO;
     }
  
      ret = -EINVAL;
  	
      switch (req->data[0]) {
      case PMU_PACKET:
  		for (i = 0; i < req->nbytes - 1; ++i)
  			req->data[i] = req->data[i+1];
  		--req->nbytes;
  		if (pmu_data_len[req->data[0]][1] != 0) {
  			req->reply[0] = ADB_RET_OK;
  			req->reply_len = 1;
  		} else
  			req->reply_len = 0;
  		ret = pmu_queue_request(req);
  		break;
      case CUDA_PACKET:
  		switch (req->data[1]) {
  		case CUDA_GET_TIME:
  			if (req->nbytes != 2)
  				break;
  			req->data[0] = PMU_READ_RTC;
  			req->nbytes = 1;
  			req->reply_len = 3;
  			req->reply[0] = CUDA_PACKET;
  			req->reply[1] = 0;
  			req->reply[2] = CUDA_GET_TIME;
  			ret = pmu_queue_request(req);
  			break;
  		case CUDA_SET_TIME:
  			if (req->nbytes != 6)
  				break;
  			req->data[0] = PMU_SET_RTC;
  			req->nbytes = 5;
  			for (i = 1; i <= 4; ++i)
  				req->data[i] = req->data[i+1];
  			req->reply_len = 3;
  			req->reply[0] = CUDA_PACKET;
  			req->reply[1] = 0;
  			req->reply[2] = CUDA_SET_TIME;
  			ret = pmu_queue_request(req);
  			break;
  		case CUDA_GET_PRAM:
  			if (req->nbytes != 4)
  				break;
  			req->data[0] = PMU_READ_NVRAM;
  			req->data[1] = req->data[2];
  			req->data[2] = req->data[3];
  			req->nbytes = 3;
  			req->reply_len = 3;
  			req->reply[0] = CUDA_PACKET;
  			req->reply[1] = 0;
  			req->reply[2] = CUDA_GET_PRAM;
  			ret = pmu_queue_request(req);
  			break;
  		case CUDA_SET_PRAM:
  			if (req->nbytes != 5)
  				break;
  			req->data[0] = PMU_WRITE_NVRAM;
  			req->data[1] = req->data[2];
  			req->data[2] = req->data[3];
  			req->data[3] = req->data[4];
  			req->nbytes = 4;
  			req->reply_len = 3;
  			req->reply[0] = CUDA_PACKET;
  			req->reply[1] = 0;
  			req->reply[2] = CUDA_SET_PRAM;
  			ret = pmu_queue_request(req);
  			break;
  		}
  		break;
      case ADB_PACKET:
  		for (i = req->nbytes - 1; i > 1; --i)
  			req->data[i+2] = req->data[i];
  		req->data[3] = req->nbytes - 2;
  		req->data[2] = pmu_adb_flags;
  		/*req->data[1] = req->data[1];*/
  		req->data[0] = PMU_ADB_CMD;
  		req->nbytes += 2;
  		req->reply_expected = 1;
  		req->reply_len = 0;
  		ret = pmu_queue_request(req);
  		break;
      }
      if (ret)
      {
      	req->complete = 1;
      	return ret;
      }
      	
      if (sync) {
  	while (!req->complete)
  		pmu_poll();
      }
  
      return 0;
  }
  
  /* Enable/disable autopolling */
  static int 
  pmu_autopoll(int devs)
  {
  	struct adb_request req;
  
  	if (!pmu_fully_inited) return -ENXIO;
  
  	if (devs) {
  		adb_dev_map = devs;
  		pmu_request(&req, NULL, 5, PMU_ADB_CMD, 0, 0x86,
  			    adb_dev_map >> 8, adb_dev_map);
  		pmu_adb_flags = 2;
  	} else {
  		pmu_request(&req, NULL, 1, PMU_ADB_POLL_OFF);
  		pmu_adb_flags = 0;
  	}
  	while (!req.complete)
  		pmu_poll();
  	return 0;
  }
  
  /* Reset the ADB bus */
  static int 
  pmu_reset_bus(void)
  {
  	struct adb_request req;
  	long timeout;
  	int save_autopoll = adb_dev_map;
  
  	if (!pmu_fully_inited) return -ENXIO;
  
  	/* anyone got a better idea?? */
  	pmu_autopoll(0);
  
  	req.nbytes = 5;
  	req.done = NULL;
  	req.data[0] = PMU_ADB_CMD;
  	req.data[1] = 0;
  	req.data[2] = 3; /* ADB_BUSRESET ??? */
  	req.data[3] = 0;
  	req.data[4] = 0;
  	req.reply_len = 0;
  	req.reply_expected = 1;
  	if (pmu_queue_request(&req) != 0)
  	{
  		printk(KERN_ERR "pmu_adb_reset_bus: pmu_queue_request failed
  ");
  		return -EIO;
  	}
  	while (!req.complete)
  		pmu_poll();
  	timeout = 100000;
  	while (!req.complete) {
  		if (--timeout < 0) {
  			printk(KERN_ERR "pmu_adb_reset_bus (reset): no response from PMU
  ");
  			return -EIO;
  		}
  		udelay(10);
  		pmu_poll();
  	}
  
  	if (save_autopoll != 0)
  		pmu_autopoll(save_autopoll);
  		
  	return 0;
  }
  
  /* Construct and send a pmu request */
  int 
  pmu_request(struct adb_request *req, void (*done)(struct adb_request *),
  	    int nbytes, ...)
  {
  	va_list list;
  	int i;
  
  	if (nbytes < 0 || nbytes > 32) {
  		printk(KERN_ERR "pmu_request: bad nbytes (%d)
  ", nbytes);
  		req->complete = 1;
  		return -EINVAL;
  	}
  	req->nbytes = nbytes;
  	req->done = done;
  	va_start(list, nbytes);
  	for (i = 0; i < nbytes; ++i)
  		req->data[i] = va_arg(list, int);
  	va_end(list);
  	if (pmu_data_len[req->data[0]][1] != 0) {
  		req->reply[0] = ADB_RET_OK;
  		req->reply_len = 1;
  	} else
  		req->reply_len = 0;
  	req->reply_expected = 0;
  	return pmu_queue_request(req);
  }
  
  int
  pmu_queue_request(struct adb_request *req)
  {
  	unsigned long flags;
  	int nsend;
  
  	if (req->nbytes <= 0) {
  		req->complete = 1;
  		return 0;
  	}
  	nsend = pmu_data_len[req->data[0]][0];
  	if (nsend >= 0 && req->nbytes != nsend + 1) {
  		req->complete = 1;
  		return -EINVAL;
  	}
  
  	req->next = NULL;
  	req->sent = 0;
  	req->complete = 0;
  	local_irq_save(flags);
  
  	if (current_req != 0) {
  		last_req->next = req;
  		last_req = req;
  	} else {
  		current_req = req;
  		last_req = req;
  		if (pmu_state == idle)
  			pmu_start();
  	}
  
  	local_irq_restore(flags);
  	return 0;
  }
  
  static void 
  send_byte(int x)
  {
  	via1[ACR] |= SR_CTRL;
  	via1[SR] = x;
  	via2[B] &= ~TREQ;		/* assert TREQ */
  }
  
  static void 
  recv_byte(void)
  {
  	char c;
  
  	via1[ACR] = (via1[ACR] | SR_EXT) & ~SR_OUT;
  	c = via1[SR];		/* resets SR */
  	via2[B] &= ~TREQ;
  }
  
  static void 
  pmu_start(void)
  {
  	unsigned long flags;
  	struct adb_request *req;
  
  	/* assert pmu_state == idle */
  	/* get the packet to send */
  	local_irq_save(flags);
  	req = current_req;
  	if (req == 0 || pmu_state != idle
  	    || (req->reply_expected && req_awaiting_reply))
  		goto out;
  
  	pmu_state = sending;
  	data_index = 1;
  	data_len = pmu_data_len[req->data[0]][0];
  
  	/* set the shift register to shift out and send a byte */
  	send_byte(req->data[0]);
  
  out:
  	local_irq_restore(flags);
  }
  
  void 
  pmu_poll(void)
  {
  	unsigned long flags;
  
  	local_irq_save(flags);
  	if (via1[IFR] & SR_INT) {
  		via1[IFR] = SR_INT;
  		pmu_interrupt(IRQ_MAC_ADB_SR, NULL);
  	}
  	if (via1[IFR] & CB1_INT) {
  		via1[IFR] = CB1_INT;
  		pmu_interrupt(IRQ_MAC_ADB_CL, NULL);
  	}
  	local_irq_restore(flags);
  }
  
  static irqreturn_t
  pmu_interrupt(int irq, void *dev_id)
  {
  	struct adb_request *req;
  	int timeout, bite = 0;	/* to prevent compiler warning */
  
  #if 0
  	printk("pmu_interrupt: irq %d state %d acr %02X, b %02X data_index %d/%d adb_int_pending %d
  ",
  		irq, pmu_state, (uint) via1[ACR], (uint) via2[B], data_index, data_len, adb_int_pending);
  #endif
  
  	if (irq == IRQ_MAC_ADB_CL) {		/* CB1 interrupt */
  		adb_int_pending = 1;
  	} else if (irq == IRQ_MAC_ADB_SR) {	/* SR interrupt  */
  		if (via2[B] & TACK) {
  			printk(KERN_DEBUG "PMU: SR_INT but ack still high! (%x)
  ", via2[B]);
  		}
  
  		/* if reading grab the byte */
  		if ((via1[ACR] & SR_OUT) == 0) bite = via1[SR];
  
  		/* reset TREQ and wait for TACK to go high */
  		via2[B] |= TREQ;
  		timeout = 3200;
  		while (!(via2[B] & TACK)) {
  			if (--timeout < 0) {
  				printk(KERN_ERR "PMU not responding (!ack)
  ");
  				goto finish;
  			}
  			udelay(10);
  		}
  
  		switch (pmu_state) {
  		case sending:
  			req = current_req;
  			if (data_len < 0) {
  				data_len = req->nbytes - 1;
  				send_byte(data_len);
  				break;
  			}
  			if (data_index <= data_len) {
  				send_byte(req->data[data_index++]);
  				break;
  			}
  			req->sent = 1;
  			data_len = pmu_data_len[req->data[0]][1];
  			if (data_len == 0) {
  				pmu_state = idle;
  				current_req = req->next;
  				if (req->reply_expected)
  					req_awaiting_reply = req;
  				else
  					pmu_done(req);
  			} else {
  				pmu_state = reading;
  				data_index = 0;
  				reply_ptr = req->reply + req->reply_len;
  				recv_byte();
  			}
  			break;
  
  		case intack:
  			data_index = 0;
  			data_len = -1;
  			pmu_state = reading_intr;
  			reply_ptr = interrupt_data;
  			recv_byte();
  			break;
  
  		case reading:
  		case reading_intr:
  			if (data_len == -1) {
  				data_len = bite;
  				if (bite > 32)
  					printk(KERN_ERR "PMU: bad reply len %d
  ",
  					       bite);
  			} else {
  				reply_ptr[data_index++] = bite;
  			}
  			if (data_index < data_len) {
  				recv_byte();
  				break;
  			}
  
  			if (pmu_state == reading_intr) {
  				pmu_handle_data(interrupt_data, data_index);
  			} else {
  				req = current_req;
  				current_req = req->next;
  				req->reply_len += data_index;
  				pmu_done(req);
  			}
  			pmu_state = idle;
  
  			break;
  
  		default:
  			printk(KERN_ERR "pmu_interrupt: unknown state %d?
  ",
  			       pmu_state);
  		}
  	}
  finish:
  	if (pmu_state == idle) {
  		if (adb_int_pending) {
  			pmu_state = intack;
  			send_byte(PMU_INT_ACK);
  			adb_int_pending = 0;
  		} else if (current_req) {
  			pmu_start();
  		}
  	}
  
  #if 0
  	printk("pmu_interrupt: exit state %d acr %02X, b %02X data_index %d/%d adb_int_pending %d
  ",
  		pmu_state, (uint) via1[ACR], (uint) via2[B], data_index, data_len, adb_int_pending);
  #endif
  	return IRQ_HANDLED;
  }
  
  static void 
  pmu_done(struct adb_request *req)
  {
  	req->complete = 1;
  	if (req->done)
  		(*req->done)(req);
  }
  
  /* Interrupt data could be the result data from an ADB cmd */
  static void 
  pmu_handle_data(unsigned char *data, int len)
  {
  	static int show_pmu_ints = 1;
  
  	asleep = 0;
  	if (len < 1) {
  		adb_int_pending = 0;
  		return;
  	}
  	if (data[0] & PMU_INT_ADB) {
  		if ((data[0] & PMU_INT_ADB_AUTO) == 0) {
  			struct adb_request *req = req_awaiting_reply;
  			if (req == 0) {
  				printk(KERN_ERR "PMU: extra ADB reply
  ");
  				return;
  			}
  			req_awaiting_reply = NULL;
  			if (len <= 2)
  				req->reply_len = 0;
  			else {
  				memcpy(req->reply, data + 1, len - 1);
  				req->reply_len = len - 1;
  			}
  			pmu_done(req);
  		} else {
  			adb_input(data+1, len-1, 1);
  		}
  	} else {
  		if (data[0] == 0x08 && len == 3) {
  			/* sound/brightness buttons pressed */
  			pmu_set_brightness(data[1] >> 3);
  			set_volume(data[2]);
  		} else if (show_pmu_ints
  			   && !(data[0] == PMU_INT_TICK && len == 1)) {
  			int i;
  			printk(KERN_DEBUG "pmu intr");
  			for (i = 0; i < len; ++i)
  				printk(" %.2x", data[i]);
  			printk("
  ");
  		}
  	}
  }
  
  static int backlight_level = -1;
  static int backlight_enabled = 0;
  
  #define LEVEL_TO_BRIGHT(lev)	((lev) < 1? 0x7f: 0x4a - ((lev) << 1))
  
  static void 
  pmu_enable_backlight(int on)
  {
  	struct adb_request req;
  
  	if (on) {
  	    /* first call: get current backlight value */
  	    if (backlight_level < 0) {
  		switch(pmu_kind) {
  		    case PMU_68K_V1:
  		    case PMU_68K_V2:
  			pmu_request(&req, NULL, 3, PMU_READ_NVRAM, 0x14, 0xe);
  			while (!req.complete)
  				pmu_poll();
  			printk(KERN_DEBUG "pmu: nvram returned bright: %d
  ", (int)req.reply[1]);
  			backlight_level = req.reply[1];
  			break;
  		    default:
  		        backlight_enabled = 0;
  		        return;
  		}
  	    }
  	    pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT,
  	    	LEVEL_TO_BRIGHT(backlight_level));
  	    while (!req.complete)
  		pmu_poll();
  	}
  	pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
  	    PMU_POW_BACKLIGHT | (on ? PMU_POW_ON : PMU_POW_OFF));
  	while (!req.complete)
  		pmu_poll();
  	backlight_enabled = on;
  }
  
  static void 
  pmu_set_brightness(int level)
  {
  	int bright;
  
  	backlight_level = level;
  	bright = LEVEL_TO_BRIGHT(level);
  	if (!backlight_enabled)
  		return;
  	if (bright_req_1.complete)
  		pmu_request(&bright_req_1, NULL, 2, PMU_BACKLIGHT_BRIGHT,
  		    bright);
  	if (bright_req_2.complete)
  		pmu_request(&bright_req_2, NULL, 2, PMU_POWER_CTRL,
  		    PMU_POW_BACKLIGHT | (bright < 0x7f ? PMU_POW_ON : PMU_POW_OFF));
  }
  
  void 
  pmu_enable_irled(int on)
  {
  	struct adb_request req;
  
  	pmu_request(&req, NULL, 2, PMU_POWER_CTRL, PMU_POW_IRLED |
  	    (on ? PMU_POW_ON : PMU_POW_OFF));
  	while (!req.complete)
  		pmu_poll();
  }
  
  static void 
  set_volume(int level)
  {
  }
  
  int
  pmu_present(void)
  {
  	return (pmu_kind != PMU_UNKNOWN);
  }