Unverified Commit 46e001c0 authored by Mark Brown's avatar Mark Brown
Browse files

Add `devm_dma_request_chan()` to simplify probe 

Merge series from Bence Csókás <csokas.bence@prolan.hu>:

The probe function of the atmel-quadspi driver got quite convoluted,
especially since the addition of SAMA7G5 support, that was forward-ported
from an older vendor kernel. To alleivate this - and similar problems in
the future - an effort was made to migrate as many functions as possible,
to their devm_ managed counterparts. Patch 1/2 adds the new
`devm_dma_request_chan()` function. Patch 2/2 then uses this APIs to
simplify the probe() function.
parents ac4c064f 25556911

drivers/dma/dmaengine.c

+30 −0
Original line number Diff line number Diff line
@@ -926,6 +926,36 @@ void dma_release_channel(struct dma_chan *chan) 
}

EXPORT_SYMBOL_GPL(dma_release_channel);



static void dmaenginem_release_channel(void *chan)

{

	dma_release_channel(chan);

}



/**

 * devm_dma_request_chan - try to allocate an exclusive slave channel

 * @dev:	pointer to client device structure

 * @name:	slave channel name

 *

 * Returns pointer to appropriate DMA channel on success or an error pointer.

 *

 * The operation is managed and will be undone on driver detach.

 */



struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name)

{

	struct dma_chan *chan = dma_request_chan(dev, name);

	int ret = 0;



	if (!IS_ERR(chan))

		ret = devm_add_action_or_reset(dev, dmaenginem_release_channel, chan);



	if (ret)

		return ERR_PTR(ret);



	return chan;

}

EXPORT_SYMBOL_GPL(devm_dma_request_chan);



/**

 * dmaengine_get - register interest in dma_channels

 */

drivers/spi/atmel-quadspi.c

+13 −35
Original line number Diff line number Diff line
@@ -1285,18 +1285,21 @@ static int atmel_qspi_dma_init(struct spi_controller *ctrl) 
	struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);

	int ret;



	aq->rx_chan = dma_request_chan(&aq->pdev->dev, "rx");

	aq->rx_chan = devm_dma_request_chan(&aq->pdev->dev, "rx");

	if (IS_ERR(aq->rx_chan)) {

		ret = dev_err_probe(&aq->pdev->dev, PTR_ERR(aq->rx_chan),

				    "RX DMA channel is not available\n");

		goto null_rx_chan;

		aq->rx_chan = NULL;

		return ret;

	}



	aq->tx_chan = dma_request_chan(&aq->pdev->dev, "tx");

	aq->tx_chan = devm_dma_request_chan(&aq->pdev->dev, "tx");

	if (IS_ERR(aq->tx_chan)) {

		ret = dev_err_probe(&aq->pdev->dev, PTR_ERR(aq->tx_chan),

				    "TX DMA channel is not available\n");

		goto release_rx_chan;

		aq->rx_chan = NULL;

		aq->tx_chan = NULL;

		return ret;

	}



	ctrl->dma_rx = aq->rx_chan;
@@ -1307,21 +1310,6 @@ static int atmel_qspi_dma_init(struct spi_controller *ctrl) 
		 dma_chan_name(aq->tx_chan), dma_chan_name(aq->rx_chan));



	return 0;



release_rx_chan:

	dma_release_channel(aq->rx_chan);

	aq->tx_chan = NULL;

null_rx_chan:

	aq->rx_chan = NULL;

	return ret;

}



static void atmel_qspi_dma_release(struct atmel_qspi *aq)

{

	if (aq->rx_chan)

		dma_release_channel(aq->rx_chan);

	if (aq->tx_chan)

		dma_release_channel(aq->tx_chan);

}



static const struct atmel_qspi_ops atmel_qspi_ops = {
@@ -1426,14 +1414,13 @@ static int atmel_qspi_probe(struct platform_device *pdev) 


	/* Request the IRQ */

	irq = platform_get_irq(pdev, 0);

	if (irq < 0) {

		err = irq;

		goto dma_release;

	}

	if (irq < 0)

		return irq;



	err = devm_request_irq(&pdev->dev, irq, atmel_qspi_interrupt,

			       0, dev_name(&pdev->dev), aq);

	if (err)

		goto dma_release;

		return err;



	pm_runtime_set_autosuspend_delay(&pdev->dev, 500);

	pm_runtime_use_autosuspend(&pdev->dev);
@@ -1442,22 +1429,16 @@ static int atmel_qspi_probe(struct platform_device *pdev) 


	err = atmel_qspi_init(aq);

	if (err)

		goto dma_release;

		return err;



	err = spi_register_controller(ctrl);

	if (err)

		goto dma_release;

		return err;



	pm_runtime_mark_last_busy(&pdev->dev);

	pm_runtime_put_autosuspend(&pdev->dev);



	return 0;



dma_release:

	if (aq->caps->has_dma)

		atmel_qspi_dma_release(aq);



	return err;

}



static int atmel_qspi_sama7g5_suspend(struct atmel_qspi *aq)
@@ -1507,9 +1488,6 @@ static void atmel_qspi_remove(struct platform_device *pdev) 


	ret = pm_runtime_get_sync(&pdev->dev);

	if (ret >= 0) {

		if (aq->caps->has_dma)

			atmel_qspi_dma_release(aq);



		if (aq->caps->has_gclk) {

			ret = atmel_qspi_sama7g5_suspend(aq);

			if (ret)

include/linux/dmaengine.h

+7 −0
Original line number Diff line number Diff line
@@ -1524,6 +1524,7 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, 


struct dma_chan *dma_request_chan(struct device *dev, const char *name);

struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask);

struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name);



void dma_release_channel(struct dma_chan *chan);

int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps);
@@ -1560,6 +1561,12 @@ static inline struct dma_chan *dma_request_chan_by_mask( 
{

	return ERR_PTR(-ENODEV);

}



static inline struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name)

{

	return ERR_PTR(-ENODEV);

}



static inline void dma_release_channel(struct dma_chan *chan)

{

}