Subject: [PATCH v2 1/3] dma: Add Freescale qDMA engine driver support

From: [email-masked] (Vinod Koul)
Date: Wed, 11 Nov 2015 13:44:08 +0530

On Fri, Oct 23, 2015 at 09:59:11AM +0800, Yuan Yao wrote:

> +config FSL_QDMA
> +	tristate "Freescale qDMA engine support"
> +	depends on SOC_LS1021A || ARCH_LAYERSCAPE

Where is this ARCH defined, quick grep revealed none

> +static void fsl_qdma_set_tcd_params(struct fsl_qdma_chan *fsl_chan,
> +					u64 src, u64 dst, u32 nbytes)
> +{
> +	void __iomem *addr = fsl_chan->qdma->membase;
> +	u32 reg;
> +
> +	/*
> +	 * Source address.
> +	 * Represents address bits 31-0 of a 49-bit source address.
> +	 */
> +	qdma_writel(fsl_chan->qdma, (u32)src, addr + FSL_QDMA_DLSAR);
> +	/*
> +	 * Source address.
> +	 * Represents address bits 47-32 of a 49-bit source address.
> +	 */
> +	reg = qdma_readl(fsl_chan->qdma, addr + FSL_QDMA_DLSATR);
> +	reg |= (u16)(src >> 32) & 0xffff;
> +	reg |= FSL_QDMA_SRTTYPE_R_N;
> +	qdma_writel(fsl_chan->qdma, reg, addr + FSL_QDMA_DLSATR);

How does this work on systems with enither endieness ?

Also why not use readq/writeq helpers, registers seem to be contagious

> +static enum dma_status fsl_qdma_tx_status(struct dma_chan *chan,
> +		dma_cookie_t cookie, struct dma_tx_state *txstate)
> +{
> +	return dma_cookie_status(chan, cookie, txstate);

No residue ?

> +static irqreturn_t fsl_qdma_controller_handler_err(int irq, void *dev_id)
> +{
> +	struct fsl_qdma_engine *fsl_qdma = dev_id;
> +	u32 reg;
> +
> +	reg = qdma_readl(fsl_qdma, fsl_qdma->membase + FSL_QDMA_DLSR);
> +
> +	if (reg & FSL_QDMA_DLSR_TE) {
> +		dev_err(fsl_qdma->dma_dev.dev,
> +			"Transfer error. Check your address please!\n");

It would help to print the addresses...

> +		ret = devm_request_irq(&pdev->dev, fsl_qdma->controller_irq,
> +				fsl_qdma_controller_handler, 0,
> +				"qDMA controller", fsl_qdma);
> +		if (ret) {
> +			dev_err(&pdev->dev,
> +				"Can't register qDMA controller IRQ.\n");
> +			return  ret;
> +		}
> +
> +		ret = devm_request_irq(&pdev->dev, fsl_qdma->err_irq,
> +				fsl_qdma_controller_handler_err, 0,
> +				"qDMA err", fsl_qdma);
> +		if (ret) {
> +			dev_err(&pdev->dev, "Can't register qDMA err IRQ.\n");
> +			return  ret;
> +		}

why do you want devm variant here..?

> +	dma_cap_set(DMA_PRIVATE, fsl_qdma->dma_dev.cap_mask);
> +	dma_cap_set(DMA_MEMCPY, fsl_qdma->dma_dev.cap_mask);
> +
> +	fsl_qdma->dma_dev.dev = &pdev->dev;
> +	fsl_qdma->dma_dev.device_free_chan_resources
> +		= fsl_qdma_free_chan_resources;
> +	fsl_qdma->dma_dev.device_tx_status = fsl_qdma_tx_status;
> +	fsl_qdma->dma_dev.device_prep_dma_memcpy = fsl_qdma_prep_memcpy;
> +	fsl_qdma->dma_dev.device_issue_pending = fsl_qdma_issue_pending;

No terminate_all callback?

> +static int fsl_qdma_remove(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct fsl_qdma_engine *fsl_qdma = platform_get_drvdata(pdev);
> +
> +	of_dma_controller_free(np);
> +	dma_async_device_unregister(&fsl_qdma->dma_dev);

And as i said above, the irq is left enabled, pls free that up

> +static int __init fsl_qdma_init(void)
> +{
> +	return platform_driver_register(&fsl_qdma_driver);
> +}
> +subsys_initcall(fsl_qdma_init);
> +
> +static void __exit fsl_qdma_exit(void)
> +{
> +	platform_driver_unregister(&fsl_qdma_driver);
> +}
> +module_exit(fsl_qdma_exit);

module_platform_driver please

-- 
~Vinod