Esempio n. 1
0
static int __devinit s3c24xx_spi_probe(struct platform_device *pdev)
{
	struct s3c2410_spi_info *pdata;
	struct s3c24xx_spi *hw;
	struct spi_master *master;
	struct resource *res;
	int err = 0;

	master = spi_alloc_master(&pdev->dev, sizeof(struct s3c24xx_spi));
	if (master == NULL) {
		dev_err(&pdev->dev, "No memory for spi_master\n");
		err = -ENOMEM;
		goto err_nomem;
	}

	hw = spi_master_get_devdata(master);
	memset(hw, 0, sizeof(struct s3c24xx_spi));

	hw->master = spi_master_get(master);
	hw->pdata = pdata = pdev->dev.platform_data;
	hw->dev = &pdev->dev;

	if (pdata == NULL) {
		dev_err(&pdev->dev, "No platform data supplied\n");
		err = -ENOENT;
		goto err_no_pdata;
	}

	platform_set_drvdata(pdev, hw);
	init_completion(&hw->done);

	/* initialise fiq handler */

	s3c24xx_spi_initfiq(hw);

	/* setup the master state. */

	/* the spi->mode bits understood by this driver: */
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;

	master->num_chipselect = hw->pdata->num_cs;
	master->bus_num = pdata->bus_num;

	/* setup the state for the bitbang driver */

	hw->bitbang.master         = hw->master;
	hw->bitbang.setup_transfer = s3c24xx_spi_setupxfer;
	hw->bitbang.chipselect     = s3c24xx_spi_chipsel;
	hw->bitbang.txrx_bufs      = s3c24xx_spi_txrx;

	hw->master->setup  = s3c24xx_spi_setup;
	hw->master->cleanup = s3c24xx_spi_cleanup;

	dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang);

	/* find and map our resources */

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res == NULL) {
		dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
		err = -ENOENT;
		goto err_no_iores;
	}

	hw->ioarea = request_mem_region(res->start, resource_size(res),
					pdev->name);

	if (hw->ioarea == NULL) {
		dev_err(&pdev->dev, "Cannot reserve region\n");
		err = -ENXIO;
		goto err_no_iores;
	}

	hw->regs = ioremap(res->start, resource_size(res));
	if (hw->regs == NULL) {
		dev_err(&pdev->dev, "Cannot map IO\n");
		err = -ENXIO;
		goto err_no_iomap;
	}

	hw->irq = platform_get_irq(pdev, 0);
	if (hw->irq < 0) {
		dev_err(&pdev->dev, "No IRQ specified\n");
		err = -ENOENT;
		goto err_no_irq;
	}

	err = request_irq(hw->irq, s3c24xx_spi_irq, 0, pdev->name, hw);
	if (err) {
		dev_err(&pdev->dev, "Cannot claim IRQ\n");
		goto err_no_irq;
	}

	hw->clk = clk_get(&pdev->dev, "spi");
	if (IS_ERR(hw->clk)) {
		dev_err(&pdev->dev, "No clock for device\n");
		err = PTR_ERR(hw->clk);
		goto err_no_clk;
	}

	/* setup any gpio we can */

	if (!pdata->set_cs) {
		if (pdata->pin_cs < 0) {
			dev_err(&pdev->dev, "No chipselect pin\n");
			err = -EINVAL;
			goto err_register;
		}

		err = gpio_request(pdata->pin_cs, dev_name(&pdev->dev));
		if (err) {
			dev_err(&pdev->dev, "Failed to get gpio for cs\n");
			goto err_register;
		}

		hw->set_cs = s3c24xx_spi_gpiocs;
		gpio_direction_output(pdata->pin_cs, 1);
	} else
		hw->set_cs = pdata->set_cs;

	s3c24xx_spi_initialsetup(hw);

	/* register our spi controller */

	err = spi_bitbang_start(&hw->bitbang);
	if (err) {
		dev_err(&pdev->dev, "Failed to register SPI master\n");
		goto err_register;
	}

	return 0;

 err_register:
	if (hw->set_cs == s3c24xx_spi_gpiocs)
		gpio_free(pdata->pin_cs);

	clk_disable(hw->clk);
	clk_put(hw->clk);

 err_no_clk:
	free_irq(hw->irq, hw);

 err_no_irq:
	iounmap(hw->regs);

 err_no_iomap:
	release_resource(hw->ioarea);
	kfree(hw->ioarea);

 err_no_iores:
 err_no_pdata:
	spi_master_put(hw->master);

 err_nomem:
	return err;
}
Esempio n. 2
0
static int spi_imx_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	const struct of_device_id *of_id =
			of_match_device(spi_imx_dt_ids, &pdev->dev);
	struct spi_imx_master *mxc_platform_info =
			dev_get_platdata(&pdev->dev);
	struct spi_master *master;
	struct spi_imx_data *spi_imx;
	struct resource *res;
	int i, ret, irq;

	if (!np && !mxc_platform_info) {
		dev_err(&pdev->dev, "can't get the platform data\n");
		return -EINVAL;
	}

	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
	if (!master)
		return -ENOMEM;

	platform_set_drvdata(pdev, master);

	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
	master->bus_num = np ? -1 : pdev->id;

	spi_imx = spi_master_get_devdata(master);
	spi_imx->bitbang.master = master;
	spi_imx->dev = &pdev->dev;

	spi_imx->devtype_data = of_id ? of_id->data :
		(struct spi_imx_devtype_data *)pdev->id_entry->driver_data;

	if (mxc_platform_info) {
		master->num_chipselect = mxc_platform_info->num_chipselect;
		master->cs_gpios = devm_kzalloc(&master->dev,
			sizeof(int) * master->num_chipselect, GFP_KERNEL);
		if (!master->cs_gpios)
			return -ENOMEM;

		for (i = 0; i < master->num_chipselect; i++)
			master->cs_gpios[i] = mxc_platform_info->chipselect[i];
 	}

	spi_imx->bitbang.chipselect = spi_imx_chipselect;
	spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
	spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
	spi_imx->bitbang.master->setup = spi_imx_setup;
	spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
	spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
	spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
	spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
	if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx))
		spi_imx->bitbang.master->mode_bits |= SPI_LOOP;

	init_completion(&spi_imx->xfer_done);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(spi_imx->base)) {
		ret = PTR_ERR(spi_imx->base);
		goto out_master_put;
	}
	spi_imx->base_phys = res->start;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		ret = irq;
		goto out_master_put;
	}

	ret = devm_request_irq(&pdev->dev, irq, spi_imx_isr, 0,
			       dev_name(&pdev->dev), spi_imx);
	if (ret) {
		dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
		goto out_master_put;
	}

	spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
	if (IS_ERR(spi_imx->clk_ipg)) {
		ret = PTR_ERR(spi_imx->clk_ipg);
		goto out_master_put;
	}

	spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
	if (IS_ERR(spi_imx->clk_per)) {
		ret = PTR_ERR(spi_imx->clk_per);
		goto out_master_put;
	}

	ret = clk_prepare_enable(spi_imx->clk_per);
	if (ret)
		goto out_master_put;

	ret = clk_prepare_enable(spi_imx->clk_ipg);
	if (ret)
		goto out_put_per;

	spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
	/*
	 * Only validated on i.mx6 now, can remove the constrain if validated on
	 * other chips.
	 */
	if (is_imx51_ecspi(spi_imx)) {
		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master);
		if (ret == -EPROBE_DEFER)
			goto out_clk_put;

		if (ret < 0)
			dev_err(&pdev->dev, "dma setup error %d, use pio\n",
				ret);
	}

	spi_imx->devtype_data->reset(spi_imx);

	spi_imx->devtype_data->intctrl(spi_imx, 0);

	master->dev.of_node = pdev->dev.of_node;
	ret = spi_bitbang_start(&spi_imx->bitbang);
	if (ret) {
		dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
		goto out_clk_put;
	}

	if (!master->cs_gpios) {
		dev_err(&pdev->dev, "No CS GPIOs available\n");
		ret = -EINVAL;
		goto out_clk_put;
	}

	for (i = 0; i < master->num_chipselect; i++) {
		if (!gpio_is_valid(master->cs_gpios[i]))
			continue;

		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
					DRIVER_NAME);
		if (ret) {
			dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
				master->cs_gpios[i]);
			goto out_clk_put;
		}
	}

	dev_info(&pdev->dev, "probed\n");

	clk_disable(spi_imx->clk_ipg);
	clk_disable(spi_imx->clk_per);
	return ret;

out_clk_put:
	clk_disable_unprepare(spi_imx->clk_ipg);
out_put_per:
	clk_disable_unprepare(spi_imx->clk_per);
out_master_put:
	spi_master_put(master);

	return ret;
}
Esempio n. 3
0
static int s3c64xx_spigpio_probe(struct platform_device *dev)
{
	struct s3c2410_spigpio_info *info;
	struct spi_master	*master;
	struct s3c64xx_spigpio 	*spi;

	int ret;
	int i;

	master = spi_alloc_master(&dev->dev, sizeof(struct s3c64xx_spigpio));
	if (master == NULL) {
		dev_err(&dev->dev, "failed to allocate spi master\n");
		ret = -ENOMEM;
		goto err;
	}

	spi = spi_master_get_devdata(master);

	/* copy in the platform data */
	info = spi->info = dev->dev.platform_data;

	/* setup spi bitbang adaptor */
	spi->bitbang.master = spi_master_get(master);
	spi->bitbang.master->bus_num = info->bus_num;
	spi->bitbang.master->num_chipselect=0xFFFF;

	spi->bitbang.chipselect = s3c64xx_spigpio_chipselect;


	spi->bitbang.txrx_word[SPI_MODE_0] = s3c64xx_spigpio_txrx_mode0;
	spi->bitbang.txrx_word[SPI_MODE_1] = s3c64xx_spigpio_txrx_mode1;
	spi->bitbang.txrx_word[SPI_MODE_2] = s3c64xx_spigpio_txrx_mode2;
	spi->bitbang.txrx_word[SPI_MODE_3] = s3c64xx_spigpio_txrx_mode3;

	/* set state of spi pins. */
	gpio_direction_output(info->pin_clk, 0);
	s3c_gpio_cfgpin(info->pin_clk, S3C_GPIO_OUTPUT);

	ret = spi_bitbang_start(&spi->bitbang);
	if (ret)
		goto err_no_bitbang;

	/* register the chips to go with the board */
	for (i = 0; i < spi->info->board_size; i++) {
		struct spi_device *spidev;

		dev_info(&dev->dev, "registering %p: %s\n",
			 &spi->info->board_info[i],
			 spi->info->board_info[i].modalias);

		spi->info->board_info[i].controller_data = spi;
		spidev = spi_new_device(master, spi->info->board_info + i);
		if (spidev)
			spidev->max_speed_hz =
					  spi->info->board_info[i].max_speed_hz;
	}

	return 0;

 err_no_bitbang:
	spi_master_put(spi->bitbang.master);
 err:
	return ret;
}
Esempio n. 4
0
/*
 * ubicom32_spi_gpio_probe
 */
static int ubicom32_spi_gpio_probe(struct platform_device *dev)
{
	struct ubicom32_spi_gpio_platform_data *pdata;
	struct spi_master *master;
	struct ubicom32_spi_gpio *usg;
	int ret;

	master = spi_alloc_master(&dev->dev, sizeof(struct ubicom32_spi_gpio));
	if (master == NULL) {
		dev_err(&dev->dev, "failed to allocate spi master\n");
		ret = -ENOMEM;
		goto err;
	}

	usg = (struct ubicom32_spi_gpio *)spi_master_get_devdata(master);

	platform_set_drvdata(dev, usg);

	/*
	 * Copy in the platform data
	 */
	pdata = dev->dev.platform_data;
	usg->pdata = dev->dev.platform_data;

	/*
	 * Request the GPIO lines
	 */
	ret = gpio_request(pdata->pin_mosi, "spi-mosi");
	if (ret) {
		dev_err(&dev->dev, "Failed to allocate spi-mosi GPIO\n");
		goto err;
	}

	ret = gpio_request(pdata->pin_miso, "spi-miso");
	if (ret) {
		dev_err(&dev->dev, "Failed to allocate spi-miso GPIO\n");
		goto err_nomiso;
	}

	ret = gpio_request(pdata->pin_clk, "spi-clk");
	if (ret) {
		dev_err(&dev->dev, "Failed to allocate spi-clk GPIO\n");
		goto err_noclk;
	}

	/*
	 * Setup spi-bitbang adaptor
	 */
	usg->bitbang.flags |= SPI_CS_HIGH;
	usg->bitbang.master = spi_master_get(master);
	usg->bitbang.master->bus_num = pdata->bus_num;
	usg->bitbang.master->num_chipselect = pdata->num_chipselect;
	usg->bitbang.chipselect = ubicom32_spi_gpio_chipselect;

	usg->bitbang.txrx_word[SPI_MODE_0] = ubicom32_spi_gpio_txrx_mode0;
	usg->bitbang.txrx_word[SPI_MODE_1] = ubicom32_spi_gpio_txrx_mode1;
	usg->bitbang.txrx_word[SPI_MODE_2] = ubicom32_spi_gpio_txrx_mode2;
	usg->bitbang.txrx_word[SPI_MODE_3] = ubicom32_spi_gpio_txrx_mode3;

	/*
	 * Setup the GPIO pins
	 */
	gpio_direction_output(pdata->pin_clk, pdata->clk_default);
	gpio_direction_output(pdata->pin_mosi, 0);
	gpio_direction_input(pdata->pin_miso);

	/*
	 * Ready to go
	 */
	ret = spi_bitbang_start(&usg->bitbang);
	if (ret) {
		goto err_no_bitbang;
	}

	return 0;

err_no_bitbang:
	spi_master_put(usg->bitbang.master);

	gpio_free(pdata->pin_clk);

err_noclk:
	gpio_free(pdata->pin_miso);

err_nomiso:
	gpio_free(pdata->pin_mosi);

err:
	return ret;
}
Esempio n. 5
0
static int __init xilinx_spi_of_probe(struct of_device *ofdev,
					const struct of_device_id *match)
{
	struct spi_master *master;
	struct xilinx_spi *xspi;
	struct resource r_irq_struct;
	struct resource r_mem_struct;

	struct resource *r_irq = &r_irq_struct;
	struct resource *r_mem = &r_mem_struct;
	int rc = 0;
	const u32 *prop;
	int len;

	/* Get resources(memory, IRQ) associated with the device */
	master = spi_alloc_master(&ofdev->dev, sizeof(struct xilinx_spi));

	if (master == NULL) {
		return -ENOMEM;
	}

	dev_set_drvdata(&ofdev->dev, master);

	rc = of_address_to_resource(ofdev->node, 0, r_mem);
	if (rc) {
		dev_warn(&ofdev->dev, "invalid address\n");
		goto put_master;
	}

	rc = of_irq_to_resource(ofdev->node, 0, r_irq);
	if (rc == NO_IRQ) {
		dev_warn(&ofdev->dev, "no IRQ found\n");
		goto put_master;
	}

	xspi = spi_master_get_devdata(master);
	xspi->bitbang.master = spi_master_get(master);
	xspi->bitbang.chipselect = xilinx_spi_chipselect;
	xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer;
	xspi->bitbang.txrx_bufs = xilinx_spi_txrx_bufs;
	xspi->bitbang.master->setup = xilinx_spi_setup;
	xspi->bitbang.flags |= SPI_SLAVE;
	init_completion(&xspi->done);
	xspi->rx_ptr = xspi->slave_rx_buf;

	xspi->irq = r_irq->start;

	if (!request_mem_region(r_mem->start,
			r_mem->end - r_mem->start + 1, XILINX_SPI_NAME)) {
		rc = -ENXIO;
		dev_warn(&ofdev->dev, "memory request failure\n");
		goto put_master;
	}

	xspi->regs = ioremap(r_mem->start, r_mem->end - r_mem->start + 1);
	if (xspi->regs == NULL) {
		rc = -ENOMEM;
		dev_warn(&ofdev->dev, "ioremap failure\n");
		goto release_mem;
	}
	xspi->irq = r_irq->start;

	/* dynamic bus assignment */
	master->bus_num = -1;

	/* number of slave select bits is required */
	prop = of_get_property(ofdev->node, "xlnx,num-ss-bits", &len);
	if (!prop || len < sizeof(*prop)) {
		dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n");
		goto unmap_io;
	}
	master->num_chipselect = *prop;

	/* SPI controller initializations */
	xspi_init_hw(xspi);

	/* Register for SPI Interrupt */
	rc = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi);
	if (rc != 0) {
		dev_warn(&ofdev->dev, "irq request failure: %d\n", xspi->irq);
		goto unmap_io;
	}

	rc = spi_bitbang_start(&xspi->bitbang);
	if (rc != 0) {
		dev_err(&ofdev->dev, "spi_bitbang_start FAILED\n");
		goto free_irq;
	}

	dev_info(&ofdev->dev, "at 0x%08X mapped to 0x%08X, irq=%d\n",
			(unsigned int)r_mem->start, (u32)xspi->regs, xspi->irq);

	/* Add any subnodes on the SPI bus */
	of_register_spi_devices(master, ofdev->node);

	return rc;

free_irq:
	free_irq(xspi->irq, xspi);
unmap_io:
	iounmap(xspi->regs);
release_mem:
	release_mem_region(r_mem->start, resource_size(r_mem));
put_master:
	spi_master_put(master);
	return rc;
}
Esempio n. 6
0
/*
 * OF Platform Bus Binding
 */
static int mpc52xx_spi_probe(struct platform_device *op)
{
	struct spi_master *master;
	struct mpc52xx_spi *ms;
	void __iomem *regs;
	u8 ctrl1;
	int rc, i = 0;
	int gpio_cs;

	/* MMIO registers */
	dev_dbg(&op->dev, "probing mpc5200 SPI device\n");
	regs = of_iomap(op->dev.of_node, 0);
	if (!regs)
		return -ENODEV;

	/* initialize the device */
	ctrl1 = SPI_CTRL1_SPIE | SPI_CTRL1_SPE | SPI_CTRL1_MSTR;
	out_8(regs + SPI_CTRL1, ctrl1);
	out_8(regs + SPI_CTRL2, 0x0);
	out_8(regs + SPI_DATADIR, 0xe);	/* Set output pins */
	out_8(regs + SPI_PORTDATA, 0x8);	/* Deassert /SS signal */

	/* Clear the status register and re-read it to check for a MODF
	 * failure.  This driver cannot currently handle multiple masters
	 * on the SPI bus.  This fault will also occur if the SPI signals
	 * are not connected to any pins (port_config setting) */
	in_8(regs + SPI_STATUS);
	out_8(regs + SPI_CTRL1, ctrl1);

	in_8(regs + SPI_DATA);
	if (in_8(regs + SPI_STATUS) & SPI_STATUS_MODF) {
		dev_err(&op->dev, "mode fault; is port_config correct?\n");
		rc = -EIO;
		goto err_init;
	}

	dev_dbg(&op->dev, "allocating spi_master struct\n");
	master = spi_alloc_master(&op->dev, sizeof *ms);
	if (!master) {
		rc = -ENOMEM;
		goto err_alloc;
	}

	master->transfer = mpc52xx_spi_transfer;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
	master->bits_per_word_mask = SPI_BPW_MASK(8);
	master->dev.of_node = op->dev.of_node;

	platform_set_drvdata(op, master);

	ms = spi_master_get_devdata(master);
	ms->master = master;
	ms->regs = regs;
	ms->irq0 = irq_of_parse_and_map(op->dev.of_node, 0);
	ms->irq1 = irq_of_parse_and_map(op->dev.of_node, 1);
	ms->state = mpc52xx_spi_fsmstate_idle;
	ms->ipb_freq = mpc5xxx_get_bus_frequency(op->dev.of_node);
	ms->gpio_cs_count = of_gpio_count(op->dev.of_node);
	if (ms->gpio_cs_count > 0) {
		master->num_chipselect = ms->gpio_cs_count;
		ms->gpio_cs = kmalloc_array(ms->gpio_cs_count,
					    sizeof(*ms->gpio_cs),
					    GFP_KERNEL);
		if (!ms->gpio_cs) {
			rc = -ENOMEM;
			goto err_alloc_gpio;
		}

		for (i = 0; i < ms->gpio_cs_count; i++) {
			gpio_cs = of_get_gpio(op->dev.of_node, i);
			if (!gpio_is_valid(gpio_cs)) {
				dev_err(&op->dev,
					"could not parse the gpio field in oftree\n");
				rc = -ENODEV;
				goto err_gpio;
			}

			rc = gpio_request(gpio_cs, dev_name(&op->dev));
			if (rc) {
				dev_err(&op->dev,
					"can't request spi cs gpio #%d on gpio line %d\n",
					i, gpio_cs);
				goto err_gpio;
			}

			gpio_direction_output(gpio_cs, 1);
			ms->gpio_cs[i] = gpio_cs;
		}
	}

	spin_lock_init(&ms->lock);
	INIT_LIST_HEAD(&ms->queue);
	INIT_WORK(&ms->work, mpc52xx_spi_wq);

	/* Decide if interrupts can be used */
	if (ms->irq0 && ms->irq1) {
		rc = request_irq(ms->irq0, mpc52xx_spi_irq, 0,
				  "mpc5200-spi-modf", ms);
		rc |= request_irq(ms->irq1, mpc52xx_spi_irq, 0,
				  "mpc5200-spi-spif", ms);
		if (rc) {
			free_irq(ms->irq0, ms);
			free_irq(ms->irq1, ms);
			ms->irq0 = ms->irq1 = 0;
		}
	} else {
		/* operate in polled mode */
		ms->irq0 = ms->irq1 = 0;
	}

	if (!ms->irq0)
		dev_info(&op->dev, "using polled mode\n");

	dev_dbg(&op->dev, "registering spi_master struct\n");
	rc = spi_register_master(master);
	if (rc)
		goto err_register;

	dev_info(&ms->master->dev, "registered MPC5200 SPI bus\n");

	return rc;

 err_register:
	dev_err(&ms->master->dev, "initialization failed\n");
 err_gpio:
	while (i-- > 0)
		gpio_free(ms->gpio_cs[i]);

	kfree(ms->gpio_cs);
 err_alloc_gpio:
	spi_master_put(master);
 err_alloc:
 err_init:
	iounmap(regs);
	return rc;
}
Esempio n. 7
0
static int spi_gpio_probe(struct platform_device *pdev)
{
	struct spi_master *master;
	struct spi_gpio_platform_data *pdata;
	struct spi_gpio *sp;
	struct spi_device *spidev;
	int err;

	pdata = pdev->dev.platform_data;
	if (!pdata)
		return -ENXIO;

	err = -ENOMEM;
	master = spi_alloc_master(&pdev->dev, sizeof(struct spi_gpio));
	if (!master)
		goto err_alloc_master;

	sp = spi_master_get_devdata(master);
	platform_set_drvdata(pdev, sp);
	sp->info = pdata;


	sp->bitbang.master = spi_master_get(master);
	sp->bitbang.master->bus_num = -1;
	sp->bitbang.master->num_chipselect = 1;
	sp->bitbang.chipselect = spi_gpio_chipselect;
	sp->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_mode0;
	sp->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_mode1;
	sp->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_mode2;
	sp->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_mode3;

//	gpio_direction_output(pdata->pin_cs, pdata->cs_activelow ? 1 : 0);
	gpio_line_config(pdata->pin_cs, IXP4XX_GPIO_OUT);
	gpio_line_config(pdata->pin_clk, IXP4XX_GPIO_OUT);
	gpio_line_config(pdata->pin_mosi, IXP4XX_GPIO_OUT);
	gpio_line_config(pdata->pin_miso, IXP4XX_GPIO_IN);
	gpio_line_set(pdata->pin_clk, 0);
	gpio_line_set(pdata->pin_mosi, 0);
	gpio_line_set(pdata->pin_cs, pdata->cs_activelow ? 1 : 0);

	err = spi_bitbang_start(&sp->bitbang);
	if (err)
		goto err_no_bitbang;
	err = pdata->boardinfo_setup(&sp->bi, master,
				     pdata->boardinfo_setup_data);
	if (err)
		goto err_bi_setup;
	sp->bi.controller_data = sp;
	spidev = spi_new_device(master, &sp->bi);
	if (!spidev)
		goto err_new_dev;

	return 0;

err_new_dev:
err_bi_setup:
	spi_bitbang_stop(&sp->bitbang);
err_no_bitbang:
	spi_master_put(sp->bitbang.master);
err_request_cs:
err_request_miso:
err_request_mosi:
err_request_clk:
	kfree(master);

err_alloc_master:
	return err;
}
Esempio n. 8
0
/**
 * cdns_spi_probe - Probe method for the SPI driver
 * @pdev:	Pointer to the platform_device structure
 *
 * This function initializes the driver data structures and the hardware.
 *
 * Return:	0 on success and error value on error
 */
static int cdns_spi_probe(struct platform_device *pdev)
{
	int ret = 0, irq;
	struct spi_master *master;
	struct cdns_spi *xspi;
	struct resource *res;
	u32 num_cs;

	master = spi_alloc_master(&pdev->dev, sizeof(*xspi));
	if (master == NULL)
		return -ENOMEM;

	xspi = spi_master_get_devdata(master);
	master->dev.of_node = pdev->dev.of_node;
	platform_set_drvdata(pdev, master);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	xspi->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(xspi->regs)) {
		ret = PTR_ERR(xspi->regs);
		goto remove_master;
	}

	xspi->pclk = devm_clk_get(&pdev->dev, "pclk");
	if (IS_ERR(xspi->pclk)) {
		dev_err(&pdev->dev, "pclk clock not found.\n");
		ret = PTR_ERR(xspi->pclk);
		goto remove_master;
	}

	xspi->ref_clk = devm_clk_get(&pdev->dev, "ref_clk");
	if (IS_ERR(xspi->ref_clk)) {
		dev_err(&pdev->dev, "ref_clk clock not found.\n");
		ret = PTR_ERR(xspi->ref_clk);
		goto remove_master;
	}

	ret = clk_prepare_enable(xspi->pclk);
	if (ret) {
		dev_err(&pdev->dev, "Unable to enable APB clock.\n");
		goto remove_master;
	}

	ret = clk_prepare_enable(xspi->ref_clk);
	if (ret) {
		dev_err(&pdev->dev, "Unable to enable device clock.\n");
		goto clk_dis_apb;
	}

	/* SPI controller initializations */
	cdns_spi_init_hw(xspi);

	irq = platform_get_irq(pdev, 0);
	if (irq <= 0) {
		ret = -ENXIO;
		dev_err(&pdev->dev, "irq number is invalid\n");
		goto remove_master;
	}

	ret = devm_request_irq(&pdev->dev, irq, cdns_spi_irq,
			       0, pdev->name, master);
	if (ret != 0) {
		ret = -ENXIO;
		dev_err(&pdev->dev, "request_irq failed\n");
		goto remove_master;
	}

	ret = of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs);

	if (ret < 0)
		master->num_chipselect = CDNS_SPI_DEFAULT_NUM_CS;
	else
		master->num_chipselect = num_cs;

	ret = of_property_read_u32(pdev->dev.of_node, "is-decoded-cs",
				   &xspi->is_decoded_cs);

	if (ret < 0)
		xspi->is_decoded_cs = 0;

	master->prepare_transfer_hardware = cdns_prepare_transfer_hardware;
	master->prepare_message = cdns_prepare_message;
	master->transfer_one = cdns_transfer_one;
	master->unprepare_transfer_hardware = cdns_unprepare_transfer_hardware;
	master->set_cs = cdns_spi_chipselect;
	master->mode_bits = SPI_CPOL | SPI_CPHA;

	/* Set to default valid value */
	master->max_speed_hz = clk_get_rate(xspi->ref_clk) / 4;
	xspi->speed_hz = master->max_speed_hz;

	master->bits_per_word_mask = SPI_BPW_MASK(8);

	ret = spi_register_master(master);
	if (ret) {
		dev_err(&pdev->dev, "spi_register_master failed\n");
		goto clk_dis_all;
	}

	return ret;

clk_dis_all:
	clk_disable_unprepare(xspi->ref_clk);
clk_dis_apb:
	clk_disable_unprepare(xspi->pclk);
remove_master:
	spi_master_put(master);
	return ret;
}
Esempio n. 9
0
static int spi_clps711x_probe(struct platform_device *pdev)
{
	struct spi_clps711x_data *hw;
	struct spi_master *master;
	struct resource *res;
	int irq, ret;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	master = spi_alloc_master(&pdev->dev, sizeof(*hw));
	if (!master)
		return -ENOMEM;

	master->bus_num = -1;
	master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
	master->bits_per_word_mask =  SPI_BPW_RANGE_MASK(1, 8);
	master->dev.of_node = pdev->dev.of_node;
	master->setup = spi_clps711x_setup;
	master->prepare_message = spi_clps711x_prepare_message;
	master->transfer_one = spi_clps711x_transfer_one;

	hw = spi_master_get_devdata(master);

	hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(hw->spi_clk)) {
		ret = PTR_ERR(hw->spi_clk);
		goto err_out;
	}

	hw->syscon =
		syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon3");
	if (IS_ERR(hw->syscon)) {
		ret = PTR_ERR(hw->syscon);
		goto err_out;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	hw->syncio = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(hw->syncio)) {
		ret = PTR_ERR(hw->syncio);
		goto err_out;
	}

	/* Disable extended mode due hardware problems */
	regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);

	/* Clear possible pending interrupt */
	readl(hw->syncio);

	ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
			       dev_name(&pdev->dev), master);
	if (ret)
		goto err_out;

	ret = devm_spi_register_master(&pdev->dev, master);
	if (!ret)
		return 0;

err_out:
	spi_master_put(master);

	return ret;
}
Esempio n. 10
0
static void spi_lm70llp_attach(struct parport *p)
{
    struct pardevice	*pd;
    struct spi_lm70llp	*pp;
    struct spi_master	*master;
    int			status;

    if (lm70llp) {
        printk(KERN_WARNING
               "%s: spi_lm70llp instance already loaded. Aborting.\n",
               DRVNAME);
        return;
    }

    /* TODO:  this just _assumes_ a lm70 is there ... no probe;
     * the lm70 driver could verify it, reading the manf ID.
     */

    master = spi_alloc_master(p->physport->dev, sizeof *pp);
    if (!master) {
        status = -ENOMEM;
        goto out_fail;
    }
    pp = spi_master_get_devdata(master);

    master->bus_num = -1;	/* dynamic alloc of a bus number */
    master->num_chipselect = 1;

    /*
     * SPI and bitbang hookup.
     */
    pp->bitbang.master = spi_master_get(master);
    pp->bitbang.chipselect = lm70_chipselect;
    pp->bitbang.txrx_word[SPI_MODE_0] = lm70_txrx;
    pp->bitbang.flags = SPI_3WIRE;

    /*
     * Parport hookup
     */
    pp->port = p;
    pd = parport_register_device(p, DRVNAME,
                                 NULL, NULL, NULL,
                                 PARPORT_FLAG_EXCL, pp);
    if (!pd) {
        status = -ENOMEM;
        goto out_free_master;
    }
    pp->pd = pd;

    status = parport_claim(pd);
    if (status < 0)
        goto out_parport_unreg;

    /*
     * Start SPI ...
     */
    status = spi_bitbang_start(&pp->bitbang);
    if (status < 0) {
        printk(KERN_WARNING
               "%s: spi_bitbang_start failed with status %d\n",
               DRVNAME, status);
        goto out_off_and_release;
    }

    /*
     * The modalias name MUST match the device_driver name
     * for the bus glue code to match and subsequently bind them.
     * We are binding to the generic drivers/hwmon/lm70.c device
     * driver.
     */
    strcpy(pp->info.modalias, "lm70");
    pp->info.max_speed_hz = 6 * 1000 * 1000;
    pp->info.chip_select = 0;
    pp->info.mode = SPI_3WIRE | SPI_MODE_0;

    /* power up the chip, and let the LM70 control SI/SO */
    parport_write_data(pp->port, lm70_INIT);

    /* Enable access to our primary data structure via
     * the board info's (void *)controller_data.
     */
    pp->info.controller_data = pp;
    pp->spidev_lm70 = spi_new_device(pp->bitbang.master, &pp->info);
    if (pp->spidev_lm70)
        dev_dbg(&pp->spidev_lm70->dev, "spidev_lm70 at %s\n",
                dev_name(&pp->spidev_lm70->dev));
    else {
        printk(KERN_WARNING "%s: spi_new_device failed\n", DRVNAME);
        status = -ENODEV;
        goto out_bitbang_stop;
    }
    pp->spidev_lm70->bits_per_word = 8;

    lm70llp = pp;
    return;

out_bitbang_stop:
    spi_bitbang_stop(&pp->bitbang);
out_off_and_release:
    /* power down */
    parport_write_data(pp->port, 0);
    mdelay(10);
    parport_release(pp->pd);
out_parport_unreg:
    parport_unregister_device(pd);
out_free_master:
    (void) spi_master_put(master);
out_fail:
    pr_info("%s: spi_lm70llp probe fail, status %d\n", DRVNAME, status);
}
Esempio n. 11
0
static int dspi_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct spi_master *master;
	struct fsl_dspi *dspi;
	struct resource *res;
	void __iomem *base;
	int ret = 0, cs_num, bus_num;

	master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
	if (!master)
		return -ENOMEM;

	dspi = spi_master_get_devdata(master);
	dspi->pdev = pdev;
	dspi->bitbang.master = master;
	dspi->bitbang.chipselect = dspi_chipselect;
	dspi->bitbang.setup_transfer = dspi_setup_transfer;
	dspi->bitbang.txrx_bufs = dspi_txrx_transfer;
	dspi->bitbang.master->setup = dspi_setup;
	dspi->bitbang.master->dev.of_node = pdev->dev.of_node;

	master->mode_bits = SPI_CPOL | SPI_CPHA;
	master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) |
					SPI_BPW_MASK(16);

	ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
	if (ret < 0) {
		dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
		goto out_master_put;
	}
	master->num_chipselect = cs_num;

	ret = of_property_read_u32(np, "bus-num", &bus_num);
	if (ret < 0) {
		dev_err(&pdev->dev, "can't get bus-num\n");
		goto out_master_put;
	}
	master->bus_num = bus_num;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(base)) {
		ret = PTR_ERR(base);
		goto out_master_put;
	}

	dspi_regmap_config.lock_arg = dspi;
	dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dspi", base,
						&dspi_regmap_config);
	if (IS_ERR(dspi->regmap)) {
		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
				PTR_ERR(dspi->regmap));
		return PTR_ERR(dspi->regmap);
	}

	dspi->irq = platform_get_irq(pdev, 0);
	if (dspi->irq < 0) {
		dev_err(&pdev->dev, "can't get platform irq\n");
		ret = dspi->irq;
		goto out_master_put;
	}

	ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0,
			pdev->name, dspi);
	if (ret < 0) {
		dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
		goto out_master_put;
	}

	dspi->clk = devm_clk_get(&pdev->dev, "dspi");
	if (IS_ERR(dspi->clk)) {
		ret = PTR_ERR(dspi->clk);
		dev_err(&pdev->dev, "unable to get clock\n");
		goto out_master_put;
	}
	clk_prepare_enable(dspi->clk);

	init_waitqueue_head(&dspi->waitq);
	platform_set_drvdata(pdev, master);

	ret = spi_bitbang_start(&dspi->bitbang);
	if (ret != 0) {
		dev_err(&pdev->dev, "Problem registering DSPI master\n");
		goto out_clk_put;
	}

	return ret;

out_clk_put:
	clk_disable_unprepare(dspi->clk);
out_master_put:
	spi_master_put(master);

	return ret;
}
Esempio n. 12
0
static int rockchip_spi_probe(struct platform_device *pdev)
{
	int ret = 0;
	struct rockchip_spi *rs;
	struct spi_master *master;
	struct resource *mem;

	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
	if (!master)
		return -ENOMEM;

	platform_set_drvdata(pdev, master);

	rs = spi_master_get_devdata(master);
	memset(rs, 0, sizeof(struct rockchip_spi));

	/* Get basic io resource and map it */
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(rs->regs)) {
		ret =  PTR_ERR(rs->regs);
		goto err_ioremap_resource;
	}

	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
	if (IS_ERR(rs->apb_pclk)) {
		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
		ret = PTR_ERR(rs->apb_pclk);
		goto err_ioremap_resource;
	}

	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
	if (IS_ERR(rs->spiclk)) {
		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
		ret = PTR_ERR(rs->spiclk);
		goto err_ioremap_resource;
	}

	ret = clk_prepare_enable(rs->apb_pclk);
	if (ret) {
		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
		goto err_ioremap_resource;
	}

	ret = clk_prepare_enable(rs->spiclk);
	if (ret) {
		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
		goto err_spiclk_enable;
	}

	spi_enable_chip(rs, 0);

	rs->type = SSI_MOTO_SPI;
	rs->master = master;
	rs->dev = &pdev->dev;
	rs->max_freq = clk_get_rate(rs->spiclk);

	rs->fifo_len = get_fifo_len(rs);
	if (!rs->fifo_len) {
		dev_err(&pdev->dev, "Failed to get fifo length\n");
		ret = -EINVAL;
		goto err_get_fifo_len;
	}

	spin_lock_init(&rs->lock);

	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	master->auto_runtime_pm = true;
	master->bus_num = pdev->id;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
	master->num_chipselect = 2;
	master->dev.of_node = pdev->dev.of_node;
	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);

	master->set_cs = rockchip_spi_set_cs;
	master->prepare_message = rockchip_spi_prepare_message;
	master->unprepare_message = rockchip_spi_unprepare_message;
	master->transfer_one = rockchip_spi_transfer_one;

	rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx");
	if (!rs->dma_tx.ch)
		dev_warn(rs->dev, "Failed to request TX DMA channel\n");

	rs->dma_rx.ch = dma_request_slave_channel(rs->dev, "rx");
	if (!rs->dma_rx.ch) {
		if (rs->dma_tx.ch) {
			dma_release_channel(rs->dma_tx.ch);
			rs->dma_tx.ch = NULL;
		}
		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
	}

	if (rs->dma_tx.ch && rs->dma_rx.ch) {
		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
		rs->dma_tx.direction = DMA_MEM_TO_DEV;
		rs->dma_tx.direction = DMA_DEV_TO_MEM;

		master->can_dma = rockchip_spi_can_dma;
		master->dma_tx = rs->dma_tx.ch;
		master->dma_rx = rs->dma_rx.ch;
	}

	ret = devm_spi_register_master(&pdev->dev, master);
	if (ret) {
		dev_err(&pdev->dev, "Failed to register master\n");
		goto err_register_master;
	}

	return 0;

err_register_master:
	if (rs->dma_tx.ch)
		dma_release_channel(rs->dma_tx.ch);
	if (rs->dma_rx.ch)
		dma_release_channel(rs->dma_rx.ch);
err_get_fifo_len:
	clk_disable_unprepare(rs->spiclk);
err_spiclk_enable:
	clk_disable_unprepare(rs->apb_pclk);
err_ioremap_resource:
	spi_master_put(master);

	return ret;
}
static int __devinit tiny_spi_probe(struct platform_device *pdev)
{
	struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
	struct tiny_spi *hw;
	struct spi_master *master;
	struct resource *res;
	unsigned int i;
	int err = -ENODEV;

	master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
	if (!master)
		return err;

	
	master->bus_num = pdev->id;
	master->num_chipselect = 255;
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
	master->setup = tiny_spi_setup;

	hw = spi_master_get_devdata(master);
	platform_set_drvdata(pdev, hw);

	
	hw->bitbang.master = spi_master_get(master);
	if (!hw->bitbang.master)
		return err;
	hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
	hw->bitbang.chipselect = tiny_spi_chipselect;
	hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;

	
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		goto exit_busy;
	if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
				     pdev->name))
		goto exit_busy;
	hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
					resource_size(res));
	if (!hw->base)
		goto exit_busy;
	
	hw->irq = platform_get_irq(pdev, 0);
	if (hw->irq >= 0) {
		init_completion(&hw->done);
		err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
				       pdev->name, hw);
		if (err)
			goto exit;
	}
	
	if (platp) {
		hw->gpio_cs_count = platp->gpio_cs_count;
		hw->gpio_cs = platp->gpio_cs;
		if (platp->gpio_cs_count && !platp->gpio_cs)
			goto exit_busy;
		hw->freq = platp->freq;
		hw->baudwidth = platp->baudwidth;
	} else {
		err = tiny_spi_of_probe(pdev);
		if (err)
			goto exit;
	}
	for (i = 0; i < hw->gpio_cs_count; i++) {
		err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
		if (err)
			goto exit_gpio;
		gpio_direction_output(hw->gpio_cs[i], 1);
	}
	hw->bitbang.master->num_chipselect = max(1U, hw->gpio_cs_count);

	
	err = spi_bitbang_start(&hw->bitbang);
	if (err)
		goto exit;
	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);

	return 0;

exit_gpio:
	while (i-- > 0)
		gpio_free(hw->gpio_cs[i]);
exit_busy:
	err = -EBUSY;
exit:
	platform_set_drvdata(pdev, NULL);
	spi_master_put(master);
	return err;
}
Esempio n. 14
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static int ath79_spi_probe(struct platform_device *pdev)
{
	struct spi_master *master;
	struct ath79_spi *sp;
	struct ath79_spi_platform_data *pdata;
	struct resource	*r;
	unsigned long rate;
	int ret;

	master = spi_alloc_master(&pdev->dev, sizeof(*sp));
	if (master == NULL) {
		dev_err(&pdev->dev, "failed to allocate spi master\n");
		return -ENOMEM;
	}

	sp = spi_master_get_devdata(master);
	master->dev.of_node = pdev->dev.of_node;
	platform_set_drvdata(pdev, sp);

	pdata = dev_get_platdata(&pdev->dev);

	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
	master->setup = ath79_spi_setup;
	master->cleanup = ath79_spi_cleanup;
	if (pdata) {
		master->bus_num = pdata->bus_num;
		master->num_chipselect = pdata->num_chipselect;
	}

	sp->bitbang.master = master;
	sp->bitbang.chipselect = ath79_spi_chipselect;
	sp->bitbang.txrx_word[SPI_MODE_0] = ath79_spi_txrx_mode0;
	sp->bitbang.setup_transfer = spi_bitbang_setup_transfer;
	sp->bitbang.flags = SPI_CS_HIGH;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (r == NULL) {
		ret = -ENOENT;
		goto err_put_master;
	}

	sp->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
	if (!sp->base) {
		ret = -ENXIO;
		goto err_put_master;
	}

	sp->clk = devm_clk_get(&pdev->dev, "ahb");
	if (IS_ERR(sp->clk)) {
		ret = PTR_ERR(sp->clk);
		goto err_put_master;
	}

	ret = clk_prepare_enable(sp->clk);
	if (ret)
		goto err_put_master;

	rate = DIV_ROUND_UP(clk_get_rate(sp->clk), MHZ);
	if (!rate) {
		ret = -EINVAL;
		goto err_clk_disable;
	}

	sp->rrw_delay = ATH79_SPI_RRW_DELAY_FACTOR / rate;
	dev_dbg(&pdev->dev, "register read/write delay is %u nsecs\n",
		sp->rrw_delay);

	ath79_spi_enable(sp);
	ret = spi_bitbang_start(&sp->bitbang);
	if (ret)
		goto err_disable;

	return 0;

err_disable:
	ath79_spi_disable(sp);
err_clk_disable:
	clk_disable_unprepare(sp->clk);
err_put_master:
	spi_master_put(sp->bitbang.master);

	return ret;
}