spi.c (2841a5fc375e9c573d10b82db30fa8a4cc25301c) spi.c (b158935f70b9c156903338053216dd0adf7ce31c)
1/*
2 * SPI init/core code
3 *
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by

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521 mutex_unlock(&board_lock);
522 }
523
524 return 0;
525}
526
527/*-------------------------------------------------------------------------*/
528
1/*
2 * SPI init/core code
3 *
4 * Copyright (C) 2005 David Brownell
5 * Copyright (C) 2008 Secret Lab Technologies Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by

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521 mutex_unlock(&board_lock);
522 }
523
524 return 0;
525}
526
527/*-------------------------------------------------------------------------*/
528
529static void spi_set_cs(struct spi_device *spi, bool enable)
530{
531 if (spi->mode & SPI_CS_HIGH)
532 enable = !enable;
533
534 if (spi->cs_gpio >= 0)
535 gpio_set_value(spi->cs_gpio, !enable);
536 else if (spi->master->set_cs)
537 spi->master->set_cs(spi, !enable);
538}
539
540/*
541 * spi_transfer_one_message - Default implementation of transfer_one_message()
542 *
543 * This is a standard implementation of transfer_one_message() for
544 * drivers which impelment a transfer_one() operation. It provides
545 * standard handling of delays and chip select management.
546 */
547static int spi_transfer_one_message(struct spi_master *master,
548 struct spi_message *msg)
549{
550 struct spi_transfer *xfer;
551 bool cur_cs = true;
552 bool keep_cs = false;
553 int ret = 0;
554
555 spi_set_cs(msg->spi, true);
556
557 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
558 trace_spi_transfer_start(msg, xfer);
559
560 INIT_COMPLETION(master->xfer_completion);
561
562 ret = master->transfer_one(master, msg->spi, xfer);
563 if (ret < 0) {
564 dev_err(&msg->spi->dev,
565 "SPI transfer failed: %d\n", ret);
566 goto out;
567 }
568
569 if (ret > 0)
570 wait_for_completion(&master->xfer_completion);
571
572 trace_spi_transfer_stop(msg, xfer);
573
574 if (msg->status != -EINPROGRESS)
575 goto out;
576
577 if (xfer->delay_usecs)
578 udelay(xfer->delay_usecs);
579
580 if (xfer->cs_change) {
581 if (list_is_last(&xfer->transfer_list,
582 &msg->transfers)) {
583 keep_cs = true;
584 } else {
585 cur_cs = !cur_cs;
586 spi_set_cs(msg->spi, cur_cs);
587 }
588 }
589
590 msg->actual_length += xfer->len;
591 }
592
593out:
594 if (ret != 0 || !keep_cs)
595 spi_set_cs(msg->spi, false);
596
597 if (msg->status == -EINPROGRESS)
598 msg->status = ret;
599
600 spi_finalize_current_message(master);
601
602 return ret;
603}
604
529/**
605/**
606 * spi_finalize_current_transfer - report completion of a transfer
607 *
608 * Called by SPI drivers using the core transfer_one_message()
609 * implementation to notify it that the current interrupt driven
610 * transfer has finised and the next one may be scheduled.
611 */
612void spi_finalize_current_transfer(struct spi_master *master)
613{
614 complete(&master->xfer_completion);
615}
616EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
617
618/**
530 * spi_pump_messages - kthread work function which processes spi message queue
531 * @work: pointer to kthread work struct contained in the master struct
532 *
533 * This function checks if there is any spi message in the queue that
534 * needs processing and if so call out to the driver to initialize hardware
535 * and transfer each message.
536 *
537 */

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831}
832
833static int spi_master_initialize_queue(struct spi_master *master)
834{
835 int ret;
836
837 master->queued = true;
838 master->transfer = spi_queued_transfer;
619 * spi_pump_messages - kthread work function which processes spi message queue
620 * @work: pointer to kthread work struct contained in the master struct
621 *
622 * This function checks if there is any spi message in the queue that
623 * needs processing and if so call out to the driver to initialize hardware
624 * and transfer each message.
625 *
626 */

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920}
921
922static int spi_master_initialize_queue(struct spi_master *master)
923{
924 int ret;
925
926 master->queued = true;
927 master->transfer = spi_queued_transfer;
928 if (!master->transfer_one_message)
929 master->transfer_one_message = spi_transfer_one_message;
839
840 /* Initialize and start queue */
841 ret = spi_init_queue(master);
842 if (ret) {
843 dev_err(&master->dev, "problem initializing queue\n");
844 goto err_init_queue;
845 }
846 ret = spi_start_queue(master);

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1237 */
1238 master->bus_num = atomic_dec_return(&dyn_bus_id);
1239 dynamic = 1;
1240 }
1241
1242 spin_lock_init(&master->bus_lock_spinlock);
1243 mutex_init(&master->bus_lock_mutex);
1244 master->bus_lock_flag = 0;
930
931 /* Initialize and start queue */
932 ret = spi_init_queue(master);
933 if (ret) {
934 dev_err(&master->dev, "problem initializing queue\n");
935 goto err_init_queue;
936 }
937 ret = spi_start_queue(master);

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1328 */
1329 master->bus_num = atomic_dec_return(&dyn_bus_id);
1330 dynamic = 1;
1331 }
1332
1333 spin_lock_init(&master->bus_lock_spinlock);
1334 mutex_init(&master->bus_lock_mutex);
1335 master->bus_lock_flag = 0;
1336 init_completion(&master->xfer_completion);
1245
1246 /* register the device, then userspace will see it.
1247 * registration fails if the bus ID is in use.
1248 */
1249 dev_set_name(&master->dev, "spi%u", master->bus_num);
1250 status = device_add(&master->dev);
1251 if (status < 0)
1252 goto done;

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1338 /* register the device, then userspace will see it.
1339 * registration fails if the bus ID is in use.
1340 */
1341 dev_set_name(&master->dev, "spi%u", master->bus_num);
1342 status = device_add(&master->dev);
1343 if (status < 0)
1344 goto done;

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