spi_bfin5xx.c

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		drv_data->cur_chip->baud, drv_data->cur_chip->flag,
		drv_data->cur_chip->ctl_reg);

	dev_dbg(&drv_data->pdev->dev,
		"the first transfer len is %d\n",
		drv_data->cur_transfer->len);

	/* Mark as busy and launch transfers */
	tasklet_schedule(&drv_data->pump_transfers);

	drv_data->busy = 1;
	spin_unlock_irqrestore(&drv_data->lock, flags);
}

/*
 * got a msg to transfer, queue it in drv_data->queue.
 * And kick off message pumper
 */
static int transfer(struct spi_device *spi, struct spi_message *msg)
{
	struct driver_data *drv_data = spi_master_get_devdata(spi->master);
	unsigned long flags;

	spin_lock_irqsave(&drv_data->lock, flags);

	if (drv_data->run == QUEUE_STOPPED) {
		spin_unlock_irqrestore(&drv_data->lock, flags);
		return -ESHUTDOWN;
	}

	msg->actual_length = 0;
	msg->status = -EINPROGRESS;
	msg->state = START_STATE;

	dev_dbg(&spi->dev, "adding an msg in transfer() \n");
	list_add_tail(&msg->queue, &drv_data->queue);

	if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
		queue_work(drv_data->workqueue, &drv_data->pump_messages);

	spin_unlock_irqrestore(&drv_data->lock, flags);

	return 0;
}

#define MAX_SPI_SSEL	7

static u16 ssel[3][MAX_SPI_SSEL] = {
	{P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
	P_SPI0_SSEL4, P_SPI0_SSEL5,
	P_SPI0_SSEL6, P_SPI0_SSEL7},

	{P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
	P_SPI1_SSEL4, P_SPI1_SSEL5,
	P_SPI1_SSEL6, P_SPI1_SSEL7},

	{P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
	P_SPI2_SSEL4, P_SPI2_SSEL5,
	P_SPI2_SSEL6, P_SPI2_SSEL7},
};

/* first setup for new devices */
static int setup(struct spi_device *spi)
{
	struct bfin5xx_spi_chip *chip_info = NULL;
	struct chip_data *chip;
	struct driver_data *drv_data = spi_master_get_devdata(spi->master);
	u8 spi_flg;

	/* Abort device setup if requested features are not supported */
	if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
		dev_err(&spi->dev, "requested mode not fully supported\n");
		return -EINVAL;
	}

	/* Zero (the default) here means 8 bits */
	if (!spi->bits_per_word)
		spi->bits_per_word = 8;

	if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
		return -EINVAL;

	/* Only alloc (or use chip_info) on first setup */
	chip = spi_get_ctldata(spi);
	if (chip == NULL) {
		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
		if (!chip)
			return -ENOMEM;

		chip->enable_dma = 0;
		chip_info = spi->controller_data;
	}

	/* chip_info isn't always needed */
	if (chip_info) {
		/* Make sure people stop trying to set fields via ctl_reg
		 * when they should actually be using common SPI framework.
		 * Currently we let through: WOM EMISO PSSE GM SZ TIMOD.
		 * Not sure if a user actually needs/uses any of these,
		 * but let's assume (for now) they do.
		 */
		if (chip_info->ctl_reg & (SPE|MSTR|CPOL|CPHA|LSBF|SIZE)) {
			dev_err(&spi->dev, "do not set bits in ctl_reg "
				"that the SPI framework manages\n");
			return -EINVAL;
		}

		chip->enable_dma = chip_info->enable_dma != 0
		    && drv_data->master_info->enable_dma;
		chip->ctl_reg = chip_info->ctl_reg;
		chip->bits_per_word = chip_info->bits_per_word;
		chip->cs_change_per_word = chip_info->cs_change_per_word;
		chip->cs_chg_udelay = chip_info->cs_chg_udelay;
	}

	/* translate common spi framework into our register */
	if (spi->mode & SPI_CPOL)
		chip->ctl_reg |= CPOL;
	if (spi->mode & SPI_CPHA)
		chip->ctl_reg |= CPHA;
	if (spi->mode & SPI_LSB_FIRST)
		chip->ctl_reg |= LSBF;
	/* we dont support running in slave mode (yet?) */
	chip->ctl_reg |= MSTR;

	/*
	 * if any one SPI chip is registered and wants DMA, request the
	 * DMA channel for it
	 */
	if (chip->enable_dma && !drv_data->dma_requested) {
		/* register dma irq handler */
		if (request_dma(drv_data->dma_channel, "BF53x_SPI_DMA") < 0) {
			dev_dbg(&spi->dev,
				"Unable to request BlackFin SPI DMA channel\n");
			return -ENODEV;
		}
		if (set_dma_callback(drv_data->dma_channel,
			(void *)dma_irq_handler, drv_data) < 0) {
			dev_dbg(&spi->dev, "Unable to set dma callback\n");
			return -EPERM;
		}
		dma_disable_irq(drv_data->dma_channel);
		drv_data->dma_requested = 1;
	}

	/*
	 * Notice: for blackfin, the speed_hz is the value of register
	 * SPI_BAUD, not the real baudrate
	 */
	chip->baud = hz_to_spi_baud(spi->max_speed_hz);
	spi_flg = ~(1 << (spi->chip_select));
	chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select));
	chip->chip_select_num = spi->chip_select;

	switch (chip->bits_per_word) {
	case 8:
		chip->n_bytes = 1;
		chip->width = CFG_SPI_WORDSIZE8;
		chip->read = chip->cs_change_per_word ?
			u8_cs_chg_reader : u8_reader;
		chip->write = chip->cs_change_per_word ?
			u8_cs_chg_writer : u8_writer;
		chip->duplex = chip->cs_change_per_word ?
			u8_cs_chg_duplex : u8_duplex;
		break;

	case 16:
		chip->n_bytes = 2;
		chip->width = CFG_SPI_WORDSIZE16;
		chip->read = chip->cs_change_per_word ?
			u16_cs_chg_reader : u16_reader;
		chip->write = chip->cs_change_per_word ?
			u16_cs_chg_writer : u16_writer;
		chip->duplex = chip->cs_change_per_word ?
			u16_cs_chg_duplex : u16_duplex;
		break;

	default:
		dev_err(&spi->dev, "%d bits_per_word is not supported\n",
				chip->bits_per_word);
		kfree(chip);
		return -ENODEV;
	}

	dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
			spi->modalias, chip->width, chip->enable_dma);
	dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
			chip->ctl_reg, chip->flag);

	spi_set_ctldata(spi, chip);

	dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
	if ((chip->chip_select_num > 0)
		&& (chip->chip_select_num <= spi->master->num_chipselect))
		peripheral_request(ssel[spi->master->bus_num]
			[chip->chip_select_num-1], DRV_NAME);

	cs_deactive(drv_data, chip);

	return 0;
}

/*
 * callback for spi framework.
 * clean driver specific data
 */
static void cleanup(struct spi_device *spi)
{
	struct chip_data *chip = spi_get_ctldata(spi);

	if ((chip->chip_select_num > 0)
		&& (chip->chip_select_num <= spi->master->num_chipselect))
		peripheral_free(ssel[spi->master->bus_num]
					[chip->chip_select_num-1]);

	kfree(chip);
}

static inline int init_queue(struct driver_data *drv_data)
{
	INIT_LIST_HEAD(&drv_data->queue);
	spin_lock_init(&drv_data->lock);

	drv_data->run = QUEUE_STOPPED;
	drv_data->busy = 0;

	/* init transfer tasklet */
	tasklet_init(&drv_data->pump_transfers,
		     pump_transfers, (unsigned long)drv_data);

	/* init messages workqueue */
	INIT_WORK(&drv_data->pump_messages, pump_messages);
	drv_data->workqueue =
	    create_singlethread_workqueue(drv_data->master->dev.parent->bus_id);
	if (drv_data->workqueue == NULL)
		return -EBUSY;

	return 0;
}

static inline int start_queue(struct driver_data *drv_data)
{
	unsigned long flags;

	spin_lock_irqsave(&drv_data->lock, flags);

	if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
		spin_unlock_irqrestore(&drv_data->lock, flags);
		return -EBUSY;
	}

	drv_data->run = QUEUE_RUNNING;
	drv_data->cur_msg = NULL;
	drv_data->cur_transfer = NULL;
	drv_data->cur_chip = NULL;
	spin_unlock_irqrestore(&drv_data->lock, flags);

	queue_work(drv_data->workqueue, &drv_data->pump_messages);

	return 0;
}

static inline int stop_queue(struct driver_data *drv_data)
{
	unsigned long flags;
	unsigned limit = 500;
	int status = 0;

	spin_lock_irqsave(&drv_data->lock, flags);

	/*
	 * This is a bit lame, but is optimized for the common execution path.
	 * A wait_queue on the drv_data->busy could be used, but then the common
	 * execution path (pump_messages) would be required to call wake_up or
	 * friends on every SPI message. Do this instead
	 */
	drv_data->run = QUEUE_STOPPED;
	while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
		spin_unlock_irqrestore(&drv_data->lock, flags);
		msleep(10);
		spin_lock_irqsave(&drv_data->lock, flags);
	}

	if (!list_empty(&drv_data->queue) || drv_data->busy)
		status = -EBUSY;

	spin_unlock_irqrestore(&drv_data->lock, flags);

	return status;
}

static inline int destroy_queue(struct driver_data *drv_data)
{
	int status;

	status = stop_queue(drv_data);
	if (status != 0)
		return status;

	destroy_workqueue(drv_data->workqueue);

	return 0;
}

static int __init bfin5xx_spi_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct bfin5xx_spi_master *platform_info;
	struct spi_master *master;
	struct driver_data *drv_data = 0;
	struct resource *res;
	int status = 0;

	platform_info = dev->platform_data;

	/* Allocate master with space for drv_data */
	master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
	if (!master) {
		dev_err(&pdev->dev, "can not alloc spi_master\n");
		return -ENOMEM;
	}

	drv_data = spi_master_get_devdata(master);
	drv_data->master = master;
	drv_data->master_info = platform_info;
	drv_data->pdev = pdev;
	drv_data->pin_req = platform_info->pin_req;

	master->bus_num = pdev->id;
	master->num_chipselect = platform_info->num_chipselect;
	master->cleanup = cleanup;
	master->setup = setup;
	master->transfer = transfer;

	/* Find and map our resources */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res == NULL) {
		dev_err(dev, "Cannot get IORESOURCE_MEM\n");
		status = -ENOENT;
		goto out_error_get_res;
	}

	drv_data->regs_base = ioremap(res->start, (res->end - res->start + 1));
	if (drv_data->regs_base == NULL) {
		dev_err(dev, "Cannot map IO\n");
		status = -ENXIO;
		goto out_error_ioremap;
	}

	drv_data->dma_channel = platform_get_irq(pdev, 0);
	if (drv_data->dma_channel < 0) {
		dev_err(dev, "No DMA channel specified\n");
		status = -ENOENT;
		goto out_error_no_dma_ch;
	}

	/* Initial and start queue */
	status = init_queue(drv_data);
	if (status != 0) {
		dev_err(dev, "problem initializing queue\n");
		goto out_error_queue_alloc;
	}

	status = start_queue(drv_data);
	if (status != 0) {
		dev_err(dev, "problem starting queue\n");
		goto out_error_queue_alloc;
	}

	/* Register with the SPI framework */
	platform_set_drvdata(pdev, drv_data);
	status = spi_register_master(master);
	if (status != 0) {
		dev_err(dev, "problem registering spi master\n");
		goto out_error_queue_alloc;
	}

	status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
	if (status != 0) {
		dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
		goto out_error;
	}

	dev_info(dev, "%s, Version %s, regs_base@%p, dma channel@%d\n",
		DRV_DESC, DRV_VERSION, drv_data->regs_base,
		drv_data->dma_channel);
	return status;

out_error_queue_alloc:
	destroy_queue(drv_data);
out_error_no_dma_ch:
	iounmap((void *) drv_data->regs_base);
out_error_ioremap:
out_error_get_res:
out_error:
	spi_master_put(master);

	return status;
}

/* stop hardware and remove the driver */
static int __devexit bfin5xx_spi_remove(struct platform_device *pdev)
{
	struct driver_data *drv_data = platform_get_drvdata(pdev);
	int status = 0;

	if (!drv_data)
		return 0;

	/* Remove the queue */
	status = destroy_queue(drv_data);
	if (status != 0)
		return status;

	/* Disable the SSP at the peripheral and SOC level */
	bfin_spi_disable(drv_data);

	/* Release DMA */
	if (drv_data->master_info->enable_dma) {
		if (dma_channel_active(drv_data->dma_channel))
			free_dma(drv_data->dma_channel);
	}

	/* Disconnect from the SPI framework */
	spi_unregister_master(drv_data->master);

	peripheral_free_list(drv_data->pin_req);

	/* Prevent double remove */
	platform_set_drvdata(pdev, NULL);

	return 0;
}

#ifdef CONFIG_PM
static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct driver_data *drv_data = platform_get_drvdata(pdev);
	int status = 0;

	status = stop_queue(drv_data);
	if (status != 0)
		return status;

	/* stop hardware */
	bfin_spi_disable(drv_data);

	return 0;
}

static int bfin5xx_spi_resume(struct platform_device *pdev)
{
	struct driver_data *drv_data = platform_get_drvdata(pdev);
	int status = 0;

	/* Enable the SPI interface */
	bfin_spi_enable(drv_data);

	/* Start the queue running */
	status = start_queue(drv_data);
	if (status != 0) {
		dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
		return status;
	}

	return 0;
}
#else
#define bfin5xx_spi_suspend NULL
#define bfin5xx_spi_resume NULL
#endif				/* CONFIG_PM */

MODULE_ALIAS("bfin-spi-master");	/* for platform bus hotplug */
static struct platform_driver bfin5xx_spi_driver = {
	.driver	= {
		.name	= DRV_NAME,
		.owner	= THIS_MODULE,
	},
	.suspend	= bfin5xx_spi_suspend,
	.resume		= bfin5xx_spi_resume,
	.remove		= __devexit_p(bfin5xx_spi_remove),
};

static int __init bfin5xx_spi_init(void)
{
	return platform_driver_probe(&bfin5xx_spi_driver, bfin5xx_spi_probe);
}
module_init(bfin5xx_spi_init);

static void __exit bfin5xx_spi_exit(void)
{
	platform_driver_unregister(&bfin5xx_spi_driver);
}
module_exit(bfin5xx_spi_exit);