xsysace.c

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#define ACE_TASK_WRITE     3
#define ACE_FSM_NUM_TASKS  4

/* FSM state definitions */
#define ACE_FSM_STATE_IDLE               0
#define ACE_FSM_STATE_REQ_LOCK           1
#define ACE_FSM_STATE_WAIT_LOCK          2
#define ACE_FSM_STATE_WAIT_CFREADY       3
#define ACE_FSM_STATE_IDENTIFY_PREPARE   4
#define ACE_FSM_STATE_IDENTIFY_TRANSFER  5
#define ACE_FSM_STATE_IDENTIFY_COMPLETE  6
#define ACE_FSM_STATE_REQ_PREPARE        7
#define ACE_FSM_STATE_REQ_TRANSFER       8
#define ACE_FSM_STATE_REQ_COMPLETE       9
#define ACE_FSM_STATE_ERROR             10
#define ACE_FSM_NUM_STATES              11

/* Set flag to exit FSM loop and reschedule tasklet */
static inline void ace_fsm_yield(struct ace_device *ace)
{
	dev_dbg(ace->dev, "ace_fsm_yield()\n");
	tasklet_schedule(&ace->fsm_tasklet);
	ace->fsm_continue_flag = 0;
}

/* Set flag to exit FSM loop and wait for IRQ to reschedule tasklet */
static inline void ace_fsm_yieldirq(struct ace_device *ace)
{
	dev_dbg(ace->dev, "ace_fsm_yieldirq()\n");

	if (ace->irq == NO_IRQ)
		/* No IRQ assigned, so need to poll */
		tasklet_schedule(&ace->fsm_tasklet);
	ace->fsm_continue_flag = 0;
}

/* Get the next read/write request; ending requests that we don't handle */
struct request *ace_get_next_request(struct request_queue * q)
{
	struct request *req;

	while ((req = elv_next_request(q)) != NULL) {
		if (blk_fs_request(req))
			break;
		end_request(req, 0);
	}
	return req;
}

static void ace_fsm_dostate(struct ace_device *ace)
{
	struct request *req;
	u32 status;
	u16 val;
	int count;
	int i;

#if defined(DEBUG)
	dev_dbg(ace->dev, "fsm_state=%i, id_req_count=%i\n",
		ace->fsm_state, ace->id_req_count);
#endif

	switch (ace->fsm_state) {
	case ACE_FSM_STATE_IDLE:
		/* See if there is anything to do */
		if (ace->id_req_count || ace_get_next_request(ace->queue)) {
			ace->fsm_iter_num++;
			ace->fsm_state = ACE_FSM_STATE_REQ_LOCK;
			mod_timer(&ace->stall_timer, jiffies + HZ);
			if (!timer_pending(&ace->stall_timer))
				add_timer(&ace->stall_timer);
			break;
		}
		del_timer(&ace->stall_timer);
		ace->fsm_continue_flag = 0;
		break;

	case ACE_FSM_STATE_REQ_LOCK:
		if (ace_in(ace, ACE_STATUS) & ACE_STATUS_MPULOCK) {
			/* Already have the lock, jump to next state */
			ace->fsm_state = ACE_FSM_STATE_WAIT_CFREADY;
			break;
		}

		/* Request the lock */
		val = ace_in(ace, ACE_CTRL);
		ace_out(ace, ACE_CTRL, val | ACE_CTRL_LOCKREQ);
		ace->fsm_state = ACE_FSM_STATE_WAIT_LOCK;
		break;

	case ACE_FSM_STATE_WAIT_LOCK:
		if (ace_in(ace, ACE_STATUS) & ACE_STATUS_MPULOCK) {
			/* got the lock; move to next state */
			ace->fsm_state = ACE_FSM_STATE_WAIT_CFREADY;
			break;
		}

		/* wait a bit for the lock */
		ace_fsm_yield(ace);
		break;

	case ACE_FSM_STATE_WAIT_CFREADY:
		status = ace_in32(ace, ACE_STATUS);
		if (!(status & ACE_STATUS_RDYFORCFCMD) ||
		    (status & ACE_STATUS_CFBSY)) {
			/* CF card isn't ready; it needs to be polled */
			ace_fsm_yield(ace);
			break;
		}

		/* Device is ready for command; determine what to do next */
		if (ace->id_req_count)
			ace->fsm_state = ACE_FSM_STATE_IDENTIFY_PREPARE;
		else
			ace->fsm_state = ACE_FSM_STATE_REQ_PREPARE;
		break;

	case ACE_FSM_STATE_IDENTIFY_PREPARE:
		/* Send identify command */
		ace->fsm_task = ACE_TASK_IDENTIFY;
		ace->data_ptr = &ace->cf_id;
		ace->data_count = ACE_BUF_PER_SECTOR;
		ace_out(ace, ACE_SECCNTCMD, ACE_SECCNTCMD_IDENTIFY);

		/* As per datasheet, put config controller in reset */
		val = ace_in(ace, ACE_CTRL);
		ace_out(ace, ACE_CTRL, val | ACE_CTRL_CFGRESET);

		/* irq handler takes over from this point; wait for the
		 * transfer to complete */
		ace->fsm_state = ACE_FSM_STATE_IDENTIFY_TRANSFER;
		ace_fsm_yieldirq(ace);
		break;

	case ACE_FSM_STATE_IDENTIFY_TRANSFER:
		/* Check that the sysace is ready to receive data */
		status = ace_in32(ace, ACE_STATUS);
		if (status & ACE_STATUS_CFBSY) {
			dev_dbg(ace->dev, "CFBSY set; t=%i iter=%i dc=%i\n",
				ace->fsm_task, ace->fsm_iter_num,
				ace->data_count);
			ace_fsm_yield(ace);
			break;
		}
		if (!(status & ACE_STATUS_DATABUFRDY)) {
			ace_fsm_yield(ace);
			break;
		}

		/* Transfer the next buffer */
		ace->reg_ops->datain(ace);
		ace->data_count--;

		/* If there are still buffers to be transfers; jump out here */
		if (ace->data_count != 0) {
			ace_fsm_yieldirq(ace);
			break;
		}

		/* transfer finished; kick state machine */
		dev_dbg(ace->dev, "identify finished\n");
		ace->fsm_state = ACE_FSM_STATE_IDENTIFY_COMPLETE;
		break;

	case ACE_FSM_STATE_IDENTIFY_COMPLETE:
		ace_fix_driveid(&ace->cf_id);
		ace_dump_mem(&ace->cf_id, 512);	/* Debug: Dump out disk ID */

		if (ace->data_result) {
			/* Error occured, disable the disk */
			ace->media_change = 1;
			set_capacity(ace->gd, 0);
			dev_err(ace->dev, "error fetching CF id (%i)\n",
				ace->data_result);
		} else {
			ace->media_change = 0;

			/* Record disk parameters */
			set_capacity(ace->gd, ace->cf_id.lba_capacity);
			dev_info(ace->dev, "capacity: %i sectors\n",
				 ace->cf_id.lba_capacity);
		}

		/* We're done, drop to IDLE state and notify waiters */
		ace->fsm_state = ACE_FSM_STATE_IDLE;
		ace->id_result = ace->data_result;
		while (ace->id_req_count) {
			complete(&ace->id_completion);
			ace->id_req_count--;
		}
		break;

	case ACE_FSM_STATE_REQ_PREPARE:
		req = ace_get_next_request(ace->queue);
		if (!req) {
			ace->fsm_state = ACE_FSM_STATE_IDLE;
			break;
		}

		/* Okay, it's a data request, set it up for transfer */
		dev_dbg(ace->dev,
			"request: sec=%lx hcnt=%lx, ccnt=%x, dir=%i\n",
			req->sector, req->hard_nr_sectors,
			req->current_nr_sectors, rq_data_dir(req));

		ace->req = req;
		ace->data_ptr = req->buffer;
		ace->data_count = req->current_nr_sectors * ACE_BUF_PER_SECTOR;
		ace_out32(ace, ACE_MPULBA, req->sector & 0x0FFFFFFF);

		count = req->hard_nr_sectors;
		if (rq_data_dir(req)) {
			/* Kick off write request */
			dev_dbg(ace->dev, "write data\n");
			ace->fsm_task = ACE_TASK_WRITE;
			ace_out(ace, ACE_SECCNTCMD,
				count | ACE_SECCNTCMD_WRITE_DATA);
		} else {
			/* Kick off read request */
			dev_dbg(ace->dev, "read data\n");
			ace->fsm_task = ACE_TASK_READ;
			ace_out(ace, ACE_SECCNTCMD,
				count | ACE_SECCNTCMD_READ_DATA);
		}

		/* As per datasheet, put config controller in reset */
		val = ace_in(ace, ACE_CTRL);
		ace_out(ace, ACE_CTRL, val | ACE_CTRL_CFGRESET);

		/* Move to the transfer state.  The systemace will raise
		 * an interrupt once there is something to do
		 */
		ace->fsm_state = ACE_FSM_STATE_REQ_TRANSFER;
		if (ace->fsm_task == ACE_TASK_READ)
			ace_fsm_yieldirq(ace);	/* wait for data ready */
		break;

	case ACE_FSM_STATE_REQ_TRANSFER:
		/* Check that the sysace is ready to receive data */
		status = ace_in32(ace, ACE_STATUS);
		if (status & ACE_STATUS_CFBSY) {
			dev_dbg(ace->dev,
				"CFBSY set; t=%i iter=%i c=%i dc=%i irq=%i\n",
				ace->fsm_task, ace->fsm_iter_num,
				ace->req->current_nr_sectors * 16,
				ace->data_count, ace->in_irq);
			ace_fsm_yield(ace);	/* need to poll CFBSY bit */
			break;
		}
		if (!(status & ACE_STATUS_DATABUFRDY)) {
			dev_dbg(ace->dev,
				"DATABUF not set; t=%i iter=%i c=%i dc=%i irq=%i\n",
				ace->fsm_task, ace->fsm_iter_num,
				ace->req->current_nr_sectors * 16,
				ace->data_count, ace->in_irq);
			ace_fsm_yieldirq(ace);
			break;
		}

		/* Transfer the next buffer */
		i = 16;
		if (ace->fsm_task == ACE_TASK_WRITE)
			ace->reg_ops->dataout(ace);
		else
			ace->reg_ops->datain(ace);
		ace->data_count--;

		/* If there are still buffers to be transfers; jump out here */
		if (ace->data_count != 0) {
			ace_fsm_yieldirq(ace);
			break;
		}

		/* bio finished; is there another one? */
		i = ace->req->current_nr_sectors;
		if (end_that_request_first(ace->req, 1, i)) {
			/* dev_dbg(ace->dev, "next block; h=%li c=%i\n",
			 *      ace->req->hard_nr_sectors,
			 *      ace->req->current_nr_sectors);
			 */
			ace->data_ptr = ace->req->buffer;
			ace->data_count = ace->req->current_nr_sectors * 16;
			ace_fsm_yieldirq(ace);
			break;
		}

		ace->fsm_state = ACE_FSM_STATE_REQ_COMPLETE;
		break;

	case ACE_FSM_STATE_REQ_COMPLETE:
		/* Complete the block request */
		blkdev_dequeue_request(ace->req);
		end_that_request_last(ace->req, 1);
		ace->req = NULL;

		/* Finished request; go to idle state */
		ace->fsm_state = ACE_FSM_STATE_IDLE;
		break;

	default:
		ace->fsm_state = ACE_FSM_STATE_IDLE;
		break;
	}
}

static void ace_fsm_tasklet(unsigned long data)
{
	struct ace_device *ace = (void *)data;
	unsigned long flags;

	spin_lock_irqsave(&ace->lock, flags);

	/* Loop over state machine until told to stop */
	ace->fsm_continue_flag = 1;
	while (ace->fsm_continue_flag)
		ace_fsm_dostate(ace);

	spin_unlock_irqrestore(&ace->lock, flags);
}

static void ace_stall_timer(unsigned long data)
{
	struct ace_device *ace = (void *)data;
	unsigned long flags;

	dev_warn(ace->dev,
		 "kicking stalled fsm; state=%i task=%i iter=%i dc=%i\n",
		 ace->fsm_state, ace->fsm_task, ace->fsm_iter_num,
		 ace->data_count);
	spin_lock_irqsave(&ace->lock, flags);

	/* Rearm the stall timer *before* entering FSM (which may then
	 * delete the timer) */
	mod_timer(&ace->stall_timer, jiffies + HZ);

	/* Loop over state machine until told to stop */
	ace->fsm_continue_flag = 1;
	while (ace->fsm_continue_flag)
		ace_fsm_dostate(ace);

	spin_unlock_irqrestore(&ace->lock, flags);
}

/* ---------------------------------------------------------------------
 * Interrupt handling routines
 */
static int ace_interrupt_checkstate(struct ace_device *ace)
{
	u32 sreg = ace_in32(ace, ACE_STATUS);
	u16 creg = ace_in(ace, ACE_CTRL);

	/* Check for error occurance */
	if ((sreg & (ACE_STATUS_CFGERROR | ACE_STATUS_CFCERROR)) &&
	    (creg & ACE_CTRL_ERRORIRQ)) {
		dev_err(ace->dev, "transfer failure\n");
		ace_dump_regs(ace);
		return -EIO;
	}

	return 0;
}

static irqreturn_t ace_interrupt(int irq, void *dev_id)
{
	u16 creg;
	struct ace_device *ace = dev_id;

	/* be safe and get the lock */
	spin_lock(&ace->lock);
	ace->in_irq = 1;

	/* clear the interrupt */
	creg = ace_in(ace, ACE_CTRL);
	ace_out(ace, ACE_CTRL, creg | ACE_CTRL_RESETIRQ);
	ace_out(ace, ACE_CTRL, creg);

	/* check for IO failures */
	if (ace_interrupt_checkstate(ace))
		ace->data_result = -EIO;

	if (ace->fsm_task == 0) {
		dev_err(ace->dev,
			"spurious irq; stat=%.8x ctrl=%.8x cmd=%.4x\n",
			ace_in32(ace, ACE_STATUS), ace_in32(ace, ACE_CTRL),
			ace_in(ace, ACE_SECCNTCMD));
		dev_err(ace->dev, "fsm_task=%i fsm_state=%i data_count=%i\n",
			ace->fsm_task, ace->fsm_state, ace->data_count);
	}

	/* Loop over state machine until told to stop */
	ace->fsm_continue_flag = 1;
	while (ace->fsm_continue_flag)
		ace_fsm_dostate(ace);

	/* done with interrupt; drop the lock */
	ace->in_irq = 0;
	spin_unlock(&ace->lock);

	return IRQ_HANDLED;
}

/* ---------------------------------------------------------------------
 * Block ops
 */
static void ace_request(struct request_queue * q)
{
	struct request *req;
	struct ace_device *ace;

	req = ace_get_next_request(q);

	if (req) {
		ace = req->rq_disk->private_data;
		tasklet_schedule(&ace->fsm_tasklet);
	}
}

static int ace_media_changed(struct gendisk *gd)
{
	struct ace_device *ace = gd->private_data;
	dev_dbg(ace->dev, "ace_media_changed(): %i\n", ace->media_change);

	return ace->media_change;
}

static int ace_revalidate_disk(struct gendisk *gd)
{
	struct ace_device *ace = gd->private_data;
	unsigned long flags;