Re: [PATCH 2/3] crypto: brcm: Add Broadcom SPU driver

From: Mark Rutland
Date: Tue Dec 06 2016 - 09:19:26 EST


On Wed, Nov 30, 2016 at 03:07:32PM -0500, Rob Rice wrote:
> +static const struct of_device_id bcm_spu_dt_ids[] = {
> + {
> + .compatible = "brcm,spum-crypto",
> + .data = &spum_ns2_types,
> + },
> + {
> + .compatible = "brcm,spum-nsp-crypto",
> + .data = &spum_nsp_types,
> + },
> + {
> + .compatible = "brcm,spu2-crypto",
> + .data = &spu2_types,
> + },
> + {
> + .compatible = "brcm,spu2-v2-crypto",
> + .data = &spu2_v2_types,
> + },

These last two weren't in the binding document.

> + { /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, bcm_spu_dt_ids);
> +
> +static int spu_dt_read(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct spu_hw *spu = &iproc_priv.spu;
> + struct device_node *dn = pdev->dev.of_node;
> + struct resource *spu_ctrl_regs;
> + const struct of_device_id *match;
> + struct spu_type_subtype *matched_spu_type;
> + void __iomem *spu_reg_vbase[MAX_SPUS];
> + int i;
> + int err;
> +
> + if (!of_device_is_available(dn)) {
> + dev_crit(dev, "SPU device not available");
> + return -ENODEV;
> + }

How can this happen?

> + /* Count number of mailbox channels */
> + spu->num_chan = of_count_phandle_with_args(dn, "mboxes", "#mbox-cells");
> + dev_dbg(dev, "Device has %d SPU channels", spu->num_chan);
> +
> + match = of_match_device(of_match_ptr(bcm_spu_dt_ids), dev);
> + matched_spu_type = (struct spu_type_subtype *)match->data;

This cast usn't necessary.

> + spu->spu_type = matched_spu_type->type;
> + spu->spu_subtype = matched_spu_type->subtype;
> +
> + /* Read registers and count number of SPUs */
> + i = 0;
> + while ((i < MAX_SPUS) && ((spu_ctrl_regs =
> + platform_get_resource(pdev, IORESOURCE_MEM, i)) != NULL)) {
> + dev_dbg(dev,
> + "SPU %d control register region res.start = %#x, res.end = %#x",
> + i,
> + (unsigned int)spu_ctrl_regs->start,
> + (unsigned int)spu_ctrl_regs->end);
> +
> + spu_reg_vbase[i] = devm_ioremap_resource(dev, spu_ctrl_regs);
> + if (IS_ERR(spu_reg_vbase[i])) {
> + err = PTR_ERR(spu_reg_vbase[i]);
> + dev_err(&pdev->dev, "Failed to map registers: %d\n",
> + err);
> + spu_reg_vbase[i] = NULL;
> + return err;
> + }
> + i++;
> + }

These *really* sound like independent devices. There are no shared
registers, and each has its own mbox.

Why do we group them like this?

Thanks,
Mark.