static int uio_fsl_elbc_gpcm_probe()

in uio_fsl_elbc_gpcm.c [309:428]

• 94 lines of code
• 18 McCabe index (conditional complexity)

static int uio_fsl_elbc_gpcm_probe(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	struct fsl_elbc_gpcm *priv;
	struct uio_info *info;
	char *uio_name = NULL;
	struct resource res;
	unsigned int irq;
	u32 reg_br_cur;
	u32 reg_or_cur;
	u32 reg_br_new;
	u32 reg_or_new;
	int ret;

	if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
		return -ENODEV;

	/* allocate private data */
	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;
	priv->dev = &pdev->dev;
	priv->lbc = fsl_lbc_ctrl_dev->regs;

	/* get device tree data */
	ret = get_of_data(priv, node, &res, &reg_br_new, &reg_or_new,
			  &irq, &uio_name);
	if (ret)
		return ret;

	/* allocate UIO structure */
	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	/* get current BR/OR values */
	reg_br_cur = in_be32(&priv->lbc->bank[priv->bank].br);
	reg_or_cur = in_be32(&priv->lbc->bank[priv->bank].or);

	/* if bank already configured, make sure it matches */
	if ((reg_br_cur & BR_V)) {
		if ((reg_br_cur & BR_MSEL) != BR_MS_GPCM ||
		    (reg_br_cur & reg_or_cur & BR_BA)
		     != fsl_lbc_addr(res.start)) {
			dev_err(priv->dev,
				"bank in use by another peripheral\n");
			return -ENODEV;
		}

		/* warn if behavior settings changing */
		if ((reg_br_cur & ~(BR_BA | BR_V)) !=
		    (reg_br_new & ~(BR_BA | BR_V))) {
			dev_warn(priv->dev,
				 "modifying BR settings: 0x%08x -> 0x%08x",
				 reg_br_cur, reg_br_new);
		}
		if ((reg_or_cur & ~OR_GPCM_AM) != (reg_or_new & ~OR_GPCM_AM)) {
			dev_warn(priv->dev,
				 "modifying OR settings: 0x%08x -> 0x%08x",
				 reg_or_cur, reg_or_new);
		}
	}

	/* configure the bank (force base address and GPCM) */
	reg_br_new &= ~(BR_BA | BR_MSEL);
	reg_br_new |= fsl_lbc_addr(res.start) | BR_MS_GPCM | BR_V;
	out_be32(&priv->lbc->bank[priv->bank].or, reg_or_new);
	out_be32(&priv->lbc->bank[priv->bank].br, reg_br_new);

	/* map the memory resource */
	info->mem[0].internal_addr = ioremap(res.start, resource_size(&res));
	if (!info->mem[0].internal_addr) {
		dev_err(priv->dev, "failed to map chip region\n");
		return -ENODEV;
	}

	/* set all UIO data */
	info->mem[0].name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn", node);
	info->mem[0].addr = res.start;
	info->mem[0].size = resource_size(&res);
	info->mem[0].memtype = UIO_MEM_PHYS;
	info->priv = priv;
	info->name = uio_name;
	info->version = "0.0.1";
	if (irq != NO_IRQ) {
		if (priv->irq_handler) {
			info->irq = irq;
			info->irq_flags = IRQF_SHARED;
			info->handler = priv->irq_handler;
		} else {
			irq = NO_IRQ;
			dev_warn(priv->dev, "ignoring irq, no handler\n");
		}
	}

	if (priv->init)
		priv->init(info);

	/* register UIO device */
	if (uio_register_device(priv->dev, info) != 0) {
		dev_err(priv->dev, "UIO registration failed\n");
		ret = -ENODEV;
		goto out_err2;
	}

	/* store private data */
	platform_set_drvdata(pdev, info);

	dev_info(priv->dev,
		 "eLBC/GPCM device (%s) at 0x%llx, bank %d, irq=%d\n",
		 priv->name, (unsigned long long)res.start, priv->bank,
		 irq != NO_IRQ ? irq : -1);

	return 0;
out_err2:
	if (priv->shutdown)
		priv->shutdown(info, true);
	iounmap(info->mem[0].internal_addr);
	return ret;
}