Hi Biju,
On Fri, Jul 2, 2021 at 12:05 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> Add DMA Controller driver for RZ/G2L SoC.
>
> Based on the work done by Chris Brandt for RZ/A DMA driver.
>
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
Thanks for your patch!
> --- /dev/null
> +++ b/drivers/dma/sh/rz-dmac.c
> +static void rz_dmac_set_dmars_register(struct rz_dmac *dmac, int nr,
> + u32 dmars)
> +{
> + u32 dmars_offset = (nr / 2) * 4;
> + u32 dmars32;
> +
> + dmars32 = rz_dmac_ext_readl(dmac, dmars_offset);
> + if (nr % 2) {
> + dmars32 &= 0x0000ffff;
> + dmars32 |= dmars << 16;
> + } else {
> + dmars32 &= 0xffff0000;
> + dmars32 |= dmars;
> + }
An alternative to Vinod's suggestion:
shift = (nr %2) * 16;
dmars32 &= ~(0xffff << shift);
dmars32 |= dmars << shift;
> +
> + rz_dmac_ext_writel(dmac, dmars32, dmars_offset);
> +}
> +static int rz_dmac_chan_probe(struct rz_dmac *dmac,
> + struct rz_dmac_chan *channel,
> + unsigned int index)
> +{
> + struct platform_device *pdev = to_platform_device(dmac->dev);
> + struct rz_lmdesc *lmdesc;
> + char pdev_irqname[5];
> + char *irqname;
> + int ret;
> +
> + channel->index = index;
> + channel->mid_rid = -EINVAL;
> +
> + /* Request the channel interrupt. */
> + sprintf(pdev_irqname, "ch%u", index);
> + channel->irq = platform_get_irq_byname(pdev, pdev_irqname);
> + if (channel->irq < 0)
> + return -ENODEV;
Please propagate the error in channel->irq, which might be
-EPROBE_DEFER.
> +static int rz_dmac_parse_of(struct device *dev, struct rz_dmac *dmac)
> +{
> + struct device_node *np = dev->of_node;
> + int ret;
> +
> + ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels);
> + if (ret < 0) {
> + dev_err(dev, "unable to read dma-channels property\n");
> + return ret;
> + }
> +
> + if (!dmac->n_channels || dmac->n_channels > RZ_DMAC_MAX_CHANNELS) {
> + dev_err(dev, "invalid number of channels %u\n", dmac->n_channels);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int rz_dmac_probe(struct platform_device *pdev)
> +{
> + const char *irqname = "error";
> + struct dma_device *engine;
> + struct rz_dmac *dmac;
> + int channel_num;
> + int ret, i;
unsigned int i;
> + int irq;
> +
> + dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
> + if (!dmac)
> + return -ENOMEM;
> +
> + dmac->dev = &pdev->dev;
> + platform_set_drvdata(pdev, dmac);
> +
> + ret = rz_dmac_parse_of(&pdev->dev, dmac);
> + if (ret < 0)
> + return ret;
> +
> + dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels,
> + sizeof(*dmac->channels), GFP_KERNEL);
> + if (!dmac->channels)
> + return -ENOMEM;
> +
> + /* Request resources */
> + dmac->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(dmac->base))
> + return PTR_ERR(dmac->base);
> +
> + dmac->ext_base = devm_platform_ioremap_resource(pdev, 1);
> + if (IS_ERR(dmac->ext_base))
> + return PTR_ERR(dmac->ext_base);
> +
> + /* Register interrupt handler for error */
> + irq = platform_get_irq_byname(pdev, irqname);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "no error IRQ specified\n");
> + return -ENODEV;
I'd say "return dev_err_probe(&pdev->dev, irq, ..);", but
platform_get_irq_byname() already prints an error message, so
please just use "return irq;" to propagate the error, which could
be -EPROBE_DEFER.
> + }
> +static int rz_dmac_remove(struct platform_device *pdev)
> +{
> + struct rz_dmac *dmac = platform_get_drvdata(pdev);
> + int i;
unsigned int it;
> +
> + for (i = 0; i < dmac->n_channels; i++) {
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
