Input: add option to disable HP SDC driver
[pandora-kernel.git] / drivers / input / serio / hp_sdc.c
index b57370d..7b233a4 100644 (file)
  *
  * Driver theory of operation:
  *
- * hp_sdc_put does all writing to the SDC.  ISR can run on a different 
- * CPU than hp_sdc_put, but only one CPU runs hp_sdc_put at a time 
+ * hp_sdc_put does all writing to the SDC.  ISR can run on a different
+ * CPU than hp_sdc_put, but only one CPU runs hp_sdc_put at a time
  * (it cannot really benefit from SMP anyway.)  A tasket fit this perfectly.
  *
- * All data coming back from the SDC is sent via interrupt and can be read 
- * fully in the ISR, so there are no latency/throughput problems there.  
- * The problem is with output, due to the slow clock speed of the SDC 
- * compared to the CPU.  This should not be too horrible most of the time, 
- * but if used with HIL devices that support the multibyte transfer command, 
- * keeping outbound throughput flowing at the 6500KBps that the HIL is 
+ * All data coming back from the SDC is sent via interrupt and can be read
+ * fully in the ISR, so there are no latency/throughput problems there.
+ * The problem is with output, due to the slow clock speed of the SDC
+ * compared to the CPU.  This should not be too horrible most of the time,
+ * but if used with HIL devices that support the multibyte transfer command,
+ * keeping outbound throughput flowing at the 6500KBps that the HIL is
  * capable of is more than can be done at HZ=100.
  *
- * Busy polling for IBF clear wastes CPU cycles and bus cycles.  hp_sdc.ibf 
- * is set to 0 when the IBF flag in the status register has cleared.  ISR 
- * may do this, and may also access the parts of queued transactions related 
- * to reading data back from the SDC, but otherwise will not touch the 
+ * Busy polling for IBF clear wastes CPU cycles and bus cycles.  hp_sdc.ibf
+ * is set to 0 when the IBF flag in the status register has cleared.  ISR
+ * may do this, and may also access the parts of queued transactions related
+ * to reading data back from the SDC, but otherwise will not touch the
  * hp_sdc state. Whenever a register is written hp_sdc.ibf is set to 1.
  *
  * The i8042 write index and the values in the 4-byte input buffer
  * starting at 0x70 are kept track of in hp_sdc.wi, and .r7[], respectively,
- * to minimize the amount of IO needed to the SDC.  However these values 
+ * to minimize the amount of IO needed to the SDC.  However these values
  * do not need to be locked since they are only ever accessed by hp_sdc_put.
  *
  * A timer task schedules the tasklet once per second just to make
@@ -69,6 +69,7 @@
 #include <linux/time.h>
 #include <linux/slab.h>
 #include <linux/hil.h>
+#include <linux/semaphore.h>
 #include <asm/io.h>
 #include <asm/system.h>
 
@@ -100,39 +101,50 @@ EXPORT_SYMBOL(hp_sdc_release_timer_irq);
 EXPORT_SYMBOL(hp_sdc_release_hil_irq);
 EXPORT_SYMBOL(hp_sdc_release_cooked_irq);
 
+EXPORT_SYMBOL(__hp_sdc_enqueue_transaction);
 EXPORT_SYMBOL(hp_sdc_enqueue_transaction);
 EXPORT_SYMBOL(hp_sdc_dequeue_transaction);
 
+static unsigned int hp_sdc_disabled;
+module_param_named(no_hpsdc, hp_sdc_disabled, bool, 0);
+MODULE_PARM_DESC(no_hpsdc, "Do not enable HP SDC driver.");
+
 static hp_i8042_sdc    hp_sdc; /* All driver state is kept in here. */
 
 /*************** primitives for use in any context *********************/
-static inline uint8_t hp_sdc_status_in8 (void) {
+static inline uint8_t hp_sdc_status_in8(void)
+{
        uint8_t status;
        unsigned long flags;
 
        write_lock_irqsave(&hp_sdc.ibf_lock, flags);
        status = sdc_readb(hp_sdc.status_io);
-       if (!(status & HP_SDC_STATUS_IBF)) hp_sdc.ibf = 0;
+       if (!(status & HP_SDC_STATUS_IBF))
+               hp_sdc.ibf = 0;
        write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 
        return status;
 }
 
-static inline uint8_t hp_sdc_data_in8 (void) {
-       return sdc_readb(hp_sdc.data_io); 
+static inline uint8_t hp_sdc_data_in8(void)
+{
+       return sdc_readb(hp_sdc.data_io);
 }
 
-static inline void hp_sdc_status_out8 (uint8_t val) {
+static inline void hp_sdc_status_out8(uint8_t val)
+{
        unsigned long flags;
 
        write_lock_irqsave(&hp_sdc.ibf_lock, flags);
        hp_sdc.ibf = 1;
-       if ((val & 0xf0) == 0xe0) hp_sdc.wi = 0xff;
+       if ((val & 0xf0) == 0xe0)
+               hp_sdc.wi = 0xff;
        sdc_writeb(val, hp_sdc.status_io);
        write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 }
 
-static inline void hp_sdc_data_out8 (uint8_t val) {
+static inline void hp_sdc_data_out8(uint8_t val)
+{
        unsigned long flags;
 
        write_lock_irqsave(&hp_sdc.ibf_lock, flags);
@@ -141,11 +153,12 @@ static inline void hp_sdc_data_out8 (uint8_t val) {
        write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
 }
 
-/*     Care must be taken to only invoke hp_sdc_spin_ibf when 
- *     absolutely needed, or in rarely invoked subroutines.  
- *     Not only does it waste CPU cycles, it also wastes bus cycles. 
+/*     Care must be taken to only invoke hp_sdc_spin_ibf when
+ *     absolutely needed, or in rarely invoked subroutines.
+ *     Not only does it waste CPU cycles, it also wastes bus cycles.
  */
-static inline void hp_sdc_spin_ibf(void) {
+static inline void hp_sdc_spin_ibf(void)
+{
        unsigned long flags;
        rwlock_t *lock;
 
@@ -158,19 +171,21 @@ static inline void hp_sdc_spin_ibf(void) {
        }
        read_unlock(lock);
        write_lock(lock);
-       while (sdc_readb(hp_sdc.status_io) & HP_SDC_STATUS_IBF) {};
+       while (sdc_readb(hp_sdc.status_io) & HP_SDC_STATUS_IBF)
+               { }
        hp_sdc.ibf = 0;
        write_unlock_irqrestore(lock, flags);
 }
 
 
 /************************ Interrupt context functions ************************/
-static void hp_sdc_take (int irq, void *dev_id, uint8_t status, uint8_t data) {
+static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
+{
        hp_sdc_transaction *curr;
 
        read_lock(&hp_sdc.rtq_lock);
        if (hp_sdc.rcurr < 0) {
-               read_unlock(&hp_sdc.rtq_lock);
+               read_unlock(&hp_sdc.rtq_lock);
                return;
        }
        curr = hp_sdc.tq[hp_sdc.rcurr];
@@ -183,25 +198,27 @@ static void hp_sdc_take (int irq, void *dev_id, uint8_t status, uint8_t data) {
 
        if (hp_sdc.rqty <= 0) {
                /* All data has been gathered. */
-               if(curr->seq[curr->actidx] & HP_SDC_ACT_SEMAPHORE) {
-                       if (curr->act.semaphore) up(curr->act.semaphore);
-               }
-               if(curr->seq[curr->actidx] & HP_SDC_ACT_CALLBACK) {
+               if (curr->seq[curr->actidx] & HP_SDC_ACT_SEMAPHORE)
+                       if (curr->act.semaphore)
+                               up(curr->act.semaphore);
+
+               if (curr->seq[curr->actidx] & HP_SDC_ACT_CALLBACK)
                        if (curr->act.irqhook)
                                curr->act.irqhook(irq, dev_id, status, data);
-               }
+
                curr->actidx = curr->idx;
                curr->idx++;
                /* Return control of this transaction */
                write_lock(&hp_sdc.rtq_lock);
-               hp_sdc.rcurr = -1; 
+               hp_sdc.rcurr = -1;
                hp_sdc.rqty = 0;
                write_unlock(&hp_sdc.rtq_lock);
                tasklet_schedule(&hp_sdc.task);
        }
 }
 
-static irqreturn_t hp_sdc_isr(int irq, void *dev_id) {
+static irqreturn_t hp_sdc_isr(int irq, void *dev_id)
+{
        uint8_t status, data;
 
        status = hp_sdc_status_in8();
@@ -209,67 +226,74 @@ static irqreturn_t hp_sdc_isr(int irq, void *dev_id) {
        data =   hp_sdc_data_in8();
 
        /* For now we are ignoring these until we get the SDC to behave. */
-       if (((status & 0xf1) == 0x51) && data == 0x82) {
-         return IRQ_HANDLED;
-       }
+       if (((status & 0xf1) == 0x51) && data == 0x82)
+               return IRQ_HANDLED;
 
-       switch(status & HP_SDC_STATUS_IRQMASK) {
-             case 0: /* This case is not documented. */
+       switch (status & HP_SDC_STATUS_IRQMASK) {
+       case 0: /* This case is not documented. */
                break;
-             case HP_SDC_STATUS_USERTIMER:
-             case HP_SDC_STATUS_PERIODIC:
-             case HP_SDC_STATUS_TIMER:
+
+       case HP_SDC_STATUS_USERTIMER:
+       case HP_SDC_STATUS_PERIODIC:
+       case HP_SDC_STATUS_TIMER:
                read_lock(&hp_sdc.hook_lock);
-               if (hp_sdc.timer != NULL)
+               if (hp_sdc.timer != NULL)
                        hp_sdc.timer(irq, dev_id, status, data);
                read_unlock(&hp_sdc.hook_lock);
                break;
-             case HP_SDC_STATUS_REG:
+
+       case HP_SDC_STATUS_REG:
                hp_sdc_take(irq, dev_id, status, data);
                break;
-             case HP_SDC_STATUS_HILCMD:
-             case HP_SDC_STATUS_HILDATA:
+
+       case HP_SDC_STATUS_HILCMD:
+       case HP_SDC_STATUS_HILDATA:
                read_lock(&hp_sdc.hook_lock);
                if (hp_sdc.hil != NULL)
                        hp_sdc.hil(irq, dev_id, status, data);
                read_unlock(&hp_sdc.hook_lock);
                break;
-             case HP_SDC_STATUS_PUP:
+
+       case HP_SDC_STATUS_PUP:
                read_lock(&hp_sdc.hook_lock);
                if (hp_sdc.pup != NULL)
                        hp_sdc.pup(irq, dev_id, status, data);
-               else printk(KERN_INFO PREFIX "HP SDC reports successful PUP.\n");
+               else
+                       printk(KERN_INFO PREFIX "HP SDC reports successful PUP.\n");
                read_unlock(&hp_sdc.hook_lock);
                break;
-             default:
+
+       default:
                read_lock(&hp_sdc.hook_lock);
                if (hp_sdc.cooked != NULL)
                        hp_sdc.cooked(irq, dev_id, status, data);
                read_unlock(&hp_sdc.hook_lock);
                break;
        }
+
        return IRQ_HANDLED;
 }
 
 
-static irqreturn_t hp_sdc_nmisr(int irq, void *dev_id) {
+static irqreturn_t hp_sdc_nmisr(int irq, void *dev_id)
+{
        int status;
-       
+
        status = hp_sdc_status_in8();
        printk(KERN_WARNING PREFIX "NMI !\n");
 
-#if 0  
+#if 0
        if (status & HP_SDC_NMISTATUS_FHS) {
                read_lock(&hp_sdc.hook_lock);
-               if (hp_sdc.timer != NULL)
+               if (hp_sdc.timer != NULL)
                        hp_sdc.timer(irq, dev_id, status, 0);
                read_unlock(&hp_sdc.hook_lock);
-       }
-       else {
+       } else {
                /* TODO: pass this on to the HIL handler, or do SAK here? */
                printk(KERN_WARNING PREFIX "HIL NMI\n");
        }
 #endif
+
        return IRQ_HANDLED;
 }
 
@@ -278,13 +302,17 @@ static irqreturn_t hp_sdc_nmisr(int irq, void *dev_id) {
 
 unsigned long hp_sdc_put(void);
 
-static void hp_sdc_tasklet(unsigned long foo) {
-
+static void hp_sdc_tasklet(unsigned long foo)
+{
        write_lock_irq(&hp_sdc.rtq_lock);
+
        if (hp_sdc.rcurr >= 0) {
                struct timeval tv;
+
                do_gettimeofday(&tv);
-               if (tv.tv_sec > hp_sdc.rtv.tv_sec) tv.tv_usec += 1000000;
+               if (tv.tv_sec > hp_sdc.rtv.tv_sec)
+                       tv.tv_usec += USEC_PER_SEC;
+
                if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
                        hp_sdc_transaction *curr;
                        uint8_t tmp;
@@ -300,27 +328,29 @@ static void hp_sdc_tasklet(unsigned long foo) {
                        hp_sdc.rqty = 0;
                        tmp = curr->seq[curr->actidx];
                        curr->seq[curr->actidx] |= HP_SDC_ACT_DEAD;
-                       if(tmp & HP_SDC_ACT_SEMAPHORE) {
-                               if (curr->act.semaphore) 
+                       if (tmp & HP_SDC_ACT_SEMAPHORE)
+                               if (curr->act.semaphore)
                                        up(curr->act.semaphore);
-                       }
-                       if(tmp & HP_SDC_ACT_CALLBACK) {
+
+                       if (tmp & HP_SDC_ACT_CALLBACK) {
                                /* Note this means that irqhooks may be called
                                 * in tasklet/bh context.
                                 */
-                               if (curr->act.irqhook) 
+                               if (curr->act.irqhook)
                                        curr->act.irqhook(0, NULL, 0, 0);
                        }
+
                        curr->actidx = curr->idx;
                        curr->idx++;
-                       hp_sdc.rcurr = -1; 
+                       hp_sdc.rcurr = -1;
                }
        }
        write_unlock_irq(&hp_sdc.rtq_lock);
        hp_sdc_put();
 }
 
-unsigned long hp_sdc_put(void) {
+unsigned long hp_sdc_put(void)
+{
        hp_sdc_transaction *curr;
        uint8_t act;
        int idx, curridx;
@@ -333,19 +363,24 @@ unsigned long hp_sdc_put(void) {
           requires output, so we skip to the administrativa. */
        if (hp_sdc.ibf) {
                hp_sdc_status_in8();
-               if (hp_sdc.ibf) goto finish;
+               if (hp_sdc.ibf)
+                       goto finish;
        }
 
  anew:
        /* See if we are in the middle of a sequence. */
-       if (hp_sdc.wcurr < 0) hp_sdc.wcurr = 0;
+       if (hp_sdc.wcurr < 0)
+               hp_sdc.wcurr = 0;
        read_lock_irq(&hp_sdc.rtq_lock);
-       if (hp_sdc.rcurr == hp_sdc.wcurr) hp_sdc.wcurr++;
+       if (hp_sdc.rcurr == hp_sdc.wcurr)
+               hp_sdc.wcurr++;
        read_unlock_irq(&hp_sdc.rtq_lock);
-       if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
+       if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
+               hp_sdc.wcurr = 0;
        curridx = hp_sdc.wcurr;
 
-       if (hp_sdc.tq[curridx] != NULL) goto start;
+       if (hp_sdc.tq[curridx] != NULL)
+               goto start;
 
        while (++curridx != hp_sdc.wcurr) {
                if (curridx >= HP_SDC_QUEUE_LEN) {
@@ -358,7 +393,8 @@ unsigned long hp_sdc_put(void) {
                        continue;
                }
                read_unlock_irq(&hp_sdc.rtq_lock);
-               if (hp_sdc.tq[curridx] != NULL) break; /* Found one. */
+               if (hp_sdc.tq[curridx] != NULL)
+                       break; /* Found one. */
        }
        if (curridx == hp_sdc.wcurr) { /* There's nothing queued to do. */
                curridx = -1;
@@ -374,7 +410,8 @@ unsigned long hp_sdc_put(void) {
                goto finish;
        }
 
-       if (hp_sdc.wcurr == -1) goto done;
+       if (hp_sdc.wcurr == -1)
+               goto done;
 
        curr = hp_sdc.tq[curridx];
        idx = curr->actidx;
@@ -383,20 +420,23 @@ unsigned long hp_sdc_put(void) {
                hp_sdc.tq[curridx] = NULL;
                /* Interleave outbound data between the transactions. */
                hp_sdc.wcurr++;
-               if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
-               goto finish;    
+               if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
+                       hp_sdc.wcurr = 0;
+               goto finish;
        }
 
        act = curr->seq[idx];
        idx++;
 
        if (curr->idx >= curr->endidx) {
-               if (act & HP_SDC_ACT_DEALLOC) kfree(curr);
+               if (act & HP_SDC_ACT_DEALLOC)
+                       kfree(curr);
                hp_sdc.tq[curridx] = NULL;
                /* Interleave outbound data between the transactions. */
                hp_sdc.wcurr++;
-               if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
-               goto finish;    
+               if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
+                       hp_sdc.wcurr = 0;
+               goto finish;
        }
 
        while (act & HP_SDC_ACT_PRECMD) {
@@ -409,9 +449,10 @@ unsigned long hp_sdc_put(void) {
                curr->idx++;
                /* act finished? */
                if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_PRECMD)
-                 goto actdone;
+                       goto actdone;
                /* skip quantity field if data-out sequence follows. */
-               if (act & HP_SDC_ACT_DATAOUT) curr->idx++;
+               if (act & HP_SDC_ACT_DATAOUT)
+                       curr->idx++;
                goto finish;
        }
        if (act & HP_SDC_ACT_DATAOUT) {
@@ -423,15 +464,15 @@ unsigned long hp_sdc_put(void) {
                        hp_sdc_data_out8(curr->seq[curr->idx]);
                        curr->idx++;
                        /* act finished? */
-                       if ((curr->idx - idx >= qty) && 
-                           ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAOUT))
+                       if (curr->idx - idx >= qty &&
+                           (act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAOUT)
                                goto actdone;
                        goto finish;
                }
                idx += qty;
                act &= ~HP_SDC_ACT_DATAOUT;
-       }
-       else while (act & HP_SDC_ACT_DATAREG) {
+       } else
+           while (act & HP_SDC_ACT_DATAREG) {
                int mask;
                uint8_t w7[4];
 
@@ -445,26 +486,30 @@ unsigned long hp_sdc_put(void) {
                        act &= ~HP_SDC_ACT_DATAREG;
                        break;
                }
-               
+
                w7[0] = (mask & 1) ? curr->seq[++idx] : hp_sdc.r7[0];
                w7[1] = (mask & 2) ? curr->seq[++idx] : hp_sdc.r7[1];
                w7[2] = (mask & 4) ? curr->seq[++idx] : hp_sdc.r7[2];
                w7[3] = (mask & 8) ? curr->seq[++idx] : hp_sdc.r7[3];
-               
+
                if (hp_sdc.wi > 0x73 || hp_sdc.wi < 0x70 ||
-                       w7[hp_sdc.wi-0x70] == hp_sdc.r7[hp_sdc.wi-0x70]) {
+                   w7[hp_sdc.wi - 0x70] == hp_sdc.r7[hp_sdc.wi - 0x70]) {
                        int i = 0;
 
-                       /* Need to point the write index register */    
-                       while ((i < 4) && w7[i] == hp_sdc.r7[i]) i++;
+                       /* Need to point the write index register */
+                       while (i < 4 && w7[i] == hp_sdc.r7[i])
+                               i++;
+
                        if (i < 4) {
                                hp_sdc_status_out8(HP_SDC_CMD_SET_D0 + i);
                                hp_sdc.wi = 0x70 + i;
                                goto finish;
                        }
+
                        idx++;
                        if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAREG)
                                goto actdone;
+
                        curr->idx = idx;
                        act &= ~HP_SDC_ACT_DATAREG;
                        break;
@@ -476,12 +521,13 @@ unsigned long hp_sdc_put(void) {
                {
                        int i = 0;
 
-                       while ((i < 4) && w7[i] == hp_sdc.r7[i]) i++;
+                       while ((i < 4) && w7[i] == hp_sdc.r7[i])
+                               i++;
                        if (i >= 4) {
                                curr->idx = idx + 1;
-                               if ((act & HP_SDC_ACT_DURING) == 
+                               if ((act & HP_SDC_ACT_DURING) ==
                                    HP_SDC_ACT_DATAREG)
-                                       goto actdone;
+                                       goto actdone;
                        }
                }
                goto finish;
@@ -497,7 +543,7 @@ unsigned long hp_sdc_put(void) {
 
 
        if (act & HP_SDC_ACT_POSTCMD) {
-               uint8_t postcmd;
+               uint8_t postcmd;
 
                /* curr->idx should == idx at this point. */
                postcmd = curr->seq[idx];
@@ -505,12 +551,12 @@ unsigned long hp_sdc_put(void) {
                if (act & HP_SDC_ACT_DATAIN) {
 
                        /* Start a new read */
-                       hp_sdc.rqty = curr->seq[curr->idx];
+                       hp_sdc.rqty = curr->seq[curr->idx];
                        do_gettimeofday(&hp_sdc.rtv);
                        curr->idx++;
                        /* Still need to lock here in case of spurious irq. */
                        write_lock_irq(&hp_sdc.rtq_lock);
-                       hp_sdc.rcurr = curridx; 
+                       hp_sdc.rcurr = curridx;
                        write_unlock_irq(&hp_sdc.rtq_lock);
                        hp_sdc_status_out8(postcmd);
                        goto finish;
@@ -519,75 +565,86 @@ unsigned long hp_sdc_put(void) {
                goto actdone;
        }
 
-actdone:
-       if (act & HP_SDC_ACT_SEMAPHORE) {
+ actdone:
+       if (act & HP_SDC_ACT_SEMAPHORE)
                up(curr->act.semaphore);
-       }
-       else if (act & HP_SDC_ACT_CALLBACK) {
+       else if (act & HP_SDC_ACT_CALLBACK)
                curr->act.irqhook(0,NULL,0,0);
-       }
+
        if (curr->idx >= curr->endidx) { /* This transaction is over. */
-               if (act & HP_SDC_ACT_DEALLOC) kfree(curr);
+               if (act & HP_SDC_ACT_DEALLOC)
+                       kfree(curr);
                hp_sdc.tq[curridx] = NULL;
-       }
-       else {
+       } else {
                curr->actidx = idx + 1;
                curr->idx = idx + 2;
        }
        /* Interleave outbound data between the transactions. */
        hp_sdc.wcurr++;
-       if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
+       if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
+               hp_sdc.wcurr = 0;
 
  finish:
-       /* If by some quirk IBF has cleared and our ISR has run to 
+       /* If by some quirk IBF has cleared and our ISR has run to
           see that that has happened, do it all again. */
-       if (!hp_sdc.ibf && limit++ < 20) goto anew;
+       if (!hp_sdc.ibf && limit++ < 20)
+               goto anew;
 
  done:
-       if (hp_sdc.wcurr >= 0) tasklet_schedule(&hp_sdc.task);
+       if (hp_sdc.wcurr >= 0)
+               tasklet_schedule(&hp_sdc.task);
        write_unlock(&hp_sdc.lock);
+
        return 0;
 }
 
 /******* Functions called in either user or kernel context ****/
-int hp_sdc_enqueue_transaction(hp_sdc_transaction *this) {
-       unsigned long flags;
+int __hp_sdc_enqueue_transaction(hp_sdc_transaction *this)
+{
        int i;
 
        if (this == NULL) {
-               tasklet_schedule(&hp_sdc.task);
+               BUG();
                return -EINVAL;
-       };
-
-       write_lock_irqsave(&hp_sdc.lock, flags);
+       }
 
        /* Can't have same transaction on queue twice */
-       for (i=0; i < HP_SDC_QUEUE_LEN; i++)
-               if (hp_sdc.tq[i] == this) goto fail;
+       for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
+               if (hp_sdc.tq[i] == this)
+                       goto fail;
 
        this->actidx = 0;
        this->idx = 1;
 
        /* Search for empty slot */
-       for (i=0; i < HP_SDC_QUEUE_LEN; i++) {
+       for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
                if (hp_sdc.tq[i] == NULL) {
                        hp_sdc.tq[i] = this;
-                       write_unlock_irqrestore(&hp_sdc.lock, flags);
                        tasklet_schedule(&hp_sdc.task);
                        return 0;
                }
-       }
-       write_unlock_irqrestore(&hp_sdc.lock, flags);
+
        printk(KERN_WARNING PREFIX "No free slot to add transaction.\n");
        return -EBUSY;
 
  fail:
-       write_unlock_irqrestore(&hp_sdc.lock,flags);
        printk(KERN_WARNING PREFIX "Transaction add failed: transaction already queued?\n");
        return -EINVAL;
 }
 
-int hp_sdc_dequeue_transaction(hp_sdc_transaction *this) {
+int hp_sdc_enqueue_transaction(hp_sdc_transaction *this) {
+       unsigned long flags;
+       int ret;
+
+       write_lock_irqsave(&hp_sdc.lock, flags);
+       ret = __hp_sdc_enqueue_transaction(this);
+       write_unlock_irqrestore(&hp_sdc.lock,flags);
+
+       return ret;
+}
+
+int hp_sdc_dequeue_transaction(hp_sdc_transaction *this)
+{
        unsigned long flags;
        int i;
 
@@ -595,8 +652,9 @@ int hp_sdc_dequeue_transaction(hp_sdc_transaction *this) {
 
        /* TODO: don't remove it if it's not done. */
 
-       for (i=0; i < HP_SDC_QUEUE_LEN; i++)
-               if (hp_sdc.tq[i] == this) hp_sdc.tq[i] = NULL;
+       for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
+               if (hp_sdc.tq[i] == this)
+                       hp_sdc.tq[i] = NULL;
 
        write_unlock_irqrestore(&hp_sdc.lock, flags);
        return 0;
@@ -605,11 +663,11 @@ int hp_sdc_dequeue_transaction(hp_sdc_transaction *this) {
 
 
 /********************** User context functions **************************/
-int hp_sdc_request_timer_irq(hp_sdc_irqhook *callback) {
-
-       if (callback == NULL || hp_sdc.dev == NULL) {
+int hp_sdc_request_timer_irq(hp_sdc_irqhook *callback)
+{
+       if (callback == NULL || hp_sdc.dev == NULL)
                return -EINVAL;
-       }
+
        write_lock_irq(&hp_sdc.hook_lock);
        if (hp_sdc.timer != NULL) {
                write_unlock_irq(&hp_sdc.hook_lock);
@@ -629,11 +687,11 @@ int hp_sdc_request_timer_irq(hp_sdc_irqhook *callback) {
        return 0;
 }
 
-int hp_sdc_request_hil_irq(hp_sdc_irqhook *callback) {
-
-       if (callback == NULL || hp_sdc.dev == NULL) {
+int hp_sdc_request_hil_irq(hp_sdc_irqhook *callback)
+{
+       if (callback == NULL || hp_sdc.dev == NULL)
                return -EINVAL;
-       }
+
        write_lock_irq(&hp_sdc.hook_lock);
        if (hp_sdc.hil != NULL) {
                write_unlock_irq(&hp_sdc.hook_lock);
@@ -650,11 +708,11 @@ int hp_sdc_request_hil_irq(hp_sdc_irqhook *callback) {
        return 0;
 }
 
-int hp_sdc_request_cooked_irq(hp_sdc_irqhook *callback) {
-
-       if (callback == NULL || hp_sdc.dev == NULL) {
+int hp_sdc_request_cooked_irq(hp_sdc_irqhook *callback)
+{
+       if (callback == NULL || hp_sdc.dev == NULL)
                return -EINVAL;
-       }
+
        write_lock_irq(&hp_sdc.hook_lock);
        if (hp_sdc.cooked != NULL) {
                write_unlock_irq(&hp_sdc.hook_lock);
@@ -672,9 +730,8 @@ int hp_sdc_request_cooked_irq(hp_sdc_irqhook *callback) {
        return 0;
 }
 
-int hp_sdc_release_timer_irq(hp_sdc_irqhook *callback) {
-
-
+int hp_sdc_release_timer_irq(hp_sdc_irqhook *callback)
+{
        write_lock_irq(&hp_sdc.hook_lock);
        if ((callback != hp_sdc.timer) ||
            (hp_sdc.timer == NULL)) {
@@ -694,8 +751,8 @@ int hp_sdc_release_timer_irq(hp_sdc_irqhook *callback) {
        return 0;
 }
 
-int hp_sdc_release_hil_irq(hp_sdc_irqhook *callback) {
-
+int hp_sdc_release_hil_irq(hp_sdc_irqhook *callback)
+{
        write_lock_irq(&hp_sdc.hook_lock);
        if ((callback != hp_sdc.hil) ||
            (hp_sdc.hil == NULL)) {
@@ -715,8 +772,8 @@ int hp_sdc_release_hil_irq(hp_sdc_irqhook *callback) {
        return 0;
 }
 
-int hp_sdc_release_cooked_irq(hp_sdc_irqhook *callback) {
-
+int hp_sdc_release_cooked_irq(hp_sdc_irqhook *callback)
+{
        write_lock_irq(&hp_sdc.hook_lock);
        if ((callback != hp_sdc.cooked) ||
            (hp_sdc.cooked == NULL)) {
@@ -738,7 +795,8 @@ int hp_sdc_release_cooked_irq(hp_sdc_irqhook *callback) {
 
 /************************* Keepalive timer task *********************/
 
-void hp_sdc_kicker (unsigned long data) {
+void hp_sdc_kicker (unsigned long data)
+{
        tasklet_schedule(&hp_sdc.task);
        /* Re-insert the periodic task. */
        mod_timer(&hp_sdc.kicker, jiffies + HZ);
@@ -748,12 +806,12 @@ void hp_sdc_kicker (unsigned long data) {
 
 #if defined(__hppa__)
 
-static struct parisc_device_id hp_sdc_tbl[] = {
+static const struct parisc_device_id hp_sdc_tbl[] = {
        {
-               .hw_type =      HPHW_FIO, 
+               .hw_type =      HPHW_FIO,
                .hversion_rev = HVERSION_REV_ANY_ID,
                .hversion =     HVERSION_ANY_ID,
-               .sversion =     0x73, 
+               .sversion =     0x73,
         },
        { 0, }
 };
@@ -772,16 +830,15 @@ static struct parisc_driver hp_sdc_driver = {
 
 static int __init hp_sdc_init(void)
 {
-       int i;
        char *errstr;
        hp_sdc_transaction t_sync;
        uint8_t ts_sync[6];
        struct semaphore s_sync;
 
-       rwlock_init(&hp_sdc.lock);
-       rwlock_init(&hp_sdc.ibf_lock);
-       rwlock_init(&hp_sdc.rtq_lock);
-       rwlock_init(&hp_sdc.hook_lock);
+       rwlock_init(&hp_sdc.lock);
+       rwlock_init(&hp_sdc.ibf_lock);
+       rwlock_init(&hp_sdc.rtq_lock);
+       rwlock_init(&hp_sdc.hook_lock);
 
        hp_sdc.timer            = NULL;
        hp_sdc.hil              = NULL;
@@ -796,7 +853,8 @@ static int __init hp_sdc_init(void)
        hp_sdc.r7[3]            = 0xff;
        hp_sdc.ibf              = 1;
 
-       for (i = 0; i < HP_SDC_QUEUE_LEN; i++) hp_sdc.tq[i] = NULL;
+       memset(&hp_sdc.tq, 0, sizeof(hp_sdc.tq));
+
        hp_sdc.wcurr            = -1;
         hp_sdc.rcurr           = -1;
        hp_sdc.rqty             = 0;
@@ -804,27 +862,32 @@ static int __init hp_sdc_init(void)
        hp_sdc.dev_err = -ENODEV;
 
        errstr = "IO not found for";
-       if (!hp_sdc.base_io) goto err0;
+       if (!hp_sdc.base_io)
+               goto err0;
 
        errstr = "IRQ not found for";
-       if (!hp_sdc.irq) goto err0;
+       if (!hp_sdc.irq)
+               goto err0;
 
        hp_sdc.dev_err = -EBUSY;
 
 #if defined(__hppa__)
        errstr = "IO not available for";
-        if (request_region(hp_sdc.data_io, 2, hp_sdc_driver.name)) goto err0;
-#endif 
+        if (request_region(hp_sdc.data_io, 2, hp_sdc_driver.name))
+               goto err0;
+#endif
 
        errstr = "IRQ not available for";
-        if(request_irq(hp_sdc.irq, &hp_sdc_isr, 0, "HP SDC",
-                      (void *) hp_sdc.base_io)) goto err1;
+       if (request_irq(hp_sdc.irq, &hp_sdc_isr, IRQF_SHARED|IRQF_SAMPLE_RANDOM,
+                       "HP SDC", &hp_sdc))
+               goto err1;
 
        errstr = "NMI not available for";
-       if (request_irq(hp_sdc.nmi, &hp_sdc_nmisr, 0, "HP SDC NMI", 
-                       (void *) hp_sdc.base_io)) goto err2;
+       if (request_irq(hp_sdc.nmi, &hp_sdc_nmisr, IRQF_SHARED,
+                       "HP SDC NMI", &hp_sdc))
+               goto err2;
 
-       printk(KERN_INFO PREFIX "HP SDC at 0x%p, IRQ %d (NMI IRQ %d)\n", 
+       printk(KERN_INFO PREFIX "HP SDC at 0x%p, IRQ %d (NMI IRQ %d)\n",
               (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
 
        hp_sdc_status_in8();
@@ -854,13 +917,14 @@ static int __init hp_sdc_init(void)
        hp_sdc.dev_err = 0;
        return 0;
  err2:
-       free_irq(hp_sdc.irq, NULL);
+       free_irq(hp_sdc.irq, &hp_sdc);
  err1:
        release_region(hp_sdc.data_io, 2);
  err0:
-       printk(KERN_WARNING PREFIX ": %s SDC IO=0x%p IRQ=0x%x NMI=0x%x\n", 
+       printk(KERN_WARNING PREFIX ": %s SDC IO=0x%p IRQ=0x%x NMI=0x%x\n",
                errstr, (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
        hp_sdc.dev = NULL;
+
        return hp_sdc.dev_err;
 }
 
@@ -868,8 +932,10 @@ static int __init hp_sdc_init(void)
 
 static int __init hp_sdc_init_hppa(struct parisc_device *d)
 {
-       if (!d) return 1;
-       if (hp_sdc.dev != NULL) return 1;       /* We only expect one SDC */
+       if (!d)
+               return 1;
+       if (hp_sdc.dev != NULL)
+               return 1;       /* We only expect one SDC */
 
        hp_sdc.dev              = d;
        hp_sdc.irq              = d->irq;
@@ -883,11 +949,7 @@ static int __init hp_sdc_init_hppa(struct parisc_device *d)
 
 #endif /* __hppa__ */
 
-#if !defined(__mc68000__) /* Link error on m68k! */
-static void __exit hp_sdc_exit(void)
-#else
 static void hp_sdc_exit(void)
-#endif
 {
        write_lock_irq(&hp_sdc.lock);
 
@@ -898,18 +960,16 @@ static void hp_sdc_exit(void)
        /* Wait until we know this has been processed by the i8042 */
        hp_sdc_spin_ibf();
 
-       free_irq(hp_sdc.nmi, NULL);
-       free_irq(hp_sdc.irq, NULL);
+       free_irq(hp_sdc.nmi, &hp_sdc);
+       free_irq(hp_sdc.irq, &hp_sdc);
        write_unlock_irq(&hp_sdc.lock);
 
        del_timer(&hp_sdc.kicker);
 
        tasklet_kill(&hp_sdc.task);
 
-/*        release_region(hp_sdc.data_io, 2); */
-
 #if defined(__hppa__)
-       if (unregister_parisc_driver(&hp_sdc_driver)) 
+       if (unregister_parisc_driver(&hp_sdc_driver))
                printk(KERN_WARNING PREFIX "Error unregistering HP SDC");
 #endif
 }
@@ -923,7 +983,12 @@ static int __init hp_sdc_register(void)
        mm_segment_t fs;
        unsigned char i;
 #endif
-       
+
+       if (hp_sdc_disabled) {
+               printk(KERN_WARNING PREFIX "HP SDC driver disabled by no_hpsdc=1.\n");
+               return -ENODEV;
+       }
+
        hp_sdc.dev = NULL;
        hp_sdc.dev_err = 0;
 #if defined(__hppa__)
@@ -960,8 +1025,8 @@ static int __init hp_sdc_register(void)
        tq_init.seq             = tq_init_seq;
        tq_init.act.semaphore   = &tq_init_sem;
 
-       tq_init_seq[0] = 
-         HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
+       tq_init_seq[0] =
+               HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
        tq_init_seq[1] = HP_SDC_CMD_READ_KCC;
        tq_init_seq[2] = 1;
        tq_init_seq[3] = 0;
@@ -979,13 +1044,13 @@ static int __init hp_sdc_register(void)
        }
        hp_sdc.r11 = tq_init_seq[4];
        if (hp_sdc.r11 & HP_SDC_CFG_NEW) {
-               char *str;
+               const char *str;
                printk(KERN_INFO PREFIX "New style SDC\n");
                tq_init_seq[1] = HP_SDC_CMD_READ_XTD;
                tq_init.actidx          = 0;
                tq_init.idx             = 1;
                down(&tq_init_sem);
-               hp_sdc_enqueue_transaction(&tq_init);           
+               hp_sdc_enqueue_transaction(&tq_init);
                down(&tq_init_sem);
                up(&tq_init_sem);
                if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
@@ -995,15 +1060,13 @@ static int __init hp_sdc_register(void)
                hp_sdc.r7e = tq_init_seq[4];
                HP_SDC_XTD_REV_STRINGS(hp_sdc.r7e & HP_SDC_XTD_REV, str)
                printk(KERN_INFO PREFIX "Revision: %s\n", str);
-               if (hp_sdc.r7e & HP_SDC_XTD_BEEPER) {
+               if (hp_sdc.r7e & HP_SDC_XTD_BEEPER)
                        printk(KERN_INFO PREFIX "TI SN76494 beeper present\n");
-               }
-               if (hp_sdc.r7e & HP_SDC_XTD_BBRTC) {
+               if (hp_sdc.r7e & HP_SDC_XTD_BBRTC)
                        printk(KERN_INFO PREFIX "OKI MSM-58321 BBRTC present\n");
-               }
                printk(KERN_INFO PREFIX "Spunking the self test register to force PUP "
                       "on next firmware reset.\n");
-               tq_init_seq[0] = HP_SDC_ACT_PRECMD | 
+               tq_init_seq[0] = HP_SDC_ACT_PRECMD |
                        HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
                tq_init_seq[1] = HP_SDC_CMD_SET_STR;
                tq_init_seq[2] = 1;
@@ -1012,14 +1075,12 @@ static int __init hp_sdc_register(void)
                tq_init.idx             = 1;
                tq_init.endidx          = 4;
                down(&tq_init_sem);
-               hp_sdc_enqueue_transaction(&tq_init);           
+               hp_sdc_enqueue_transaction(&tq_init);
                down(&tq_init_sem);
                up(&tq_init_sem);
-       }
-       else {
-               printk(KERN_INFO PREFIX "Old style SDC (1820-%s).\n", 
+       } else
+               printk(KERN_INFO PREFIX "Old style SDC (1820-%s).\n",
                       (hp_sdc.r11 & HP_SDC_CFG_REV) ? "3300" : "2564/3087");
-       }
 
         return 0;
 }
@@ -1027,13 +1088,13 @@ static int __init hp_sdc_register(void)
 module_init(hp_sdc_register);
 module_exit(hp_sdc_exit);
 
-/* Timing notes:  These measurements taken on my 64MHz 7100-LC (715/64) 
+/* Timing notes:  These measurements taken on my 64MHz 7100-LC (715/64)
  *                                              cycles cycles-adj    time
  * between two consecutive mfctl(16)'s:              4        n/a    63ns
  * hp_sdc_spin_ibf when idle:                      119        115   1.7us
  * gsc_writeb status register:                      83         79   1.2us
  * IBF to clear after sending SET_IM:             6204       6006    93us
- * IBF to clear after sending LOAD_RT:            4467       4352    68us  
+ * IBF to clear after sending LOAD_RT:            4467       4352    68us
  * IBF to clear after sending two LOAD_RTs:      18974      18859   295us
  * READ_T1, read status/data, IRQ, call handler: 35564        n/a   556us
  * cmd to ~IBF READ_T1 2nd time right after:   5158403        n/a    81ms