[PATCH v5 3/4] remoteproc: imx_dsp_rproc: Add remoteproc driver for DSP on i.MX

[Mathieu Poirier]

Hi Shengjiu,

This pachset doesn't apply to rproc-next, which is now located here[1].  The
change is in linux-next but not in mainline yet.

https://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux.git/log/?h=rproc-next

On Sun, Sep 26, 2021 at 11:07:09AM +0800, Shengjiu Wang wrote:
> Provide a basic driver to control DSP processor found on NXP i.MX8QM,
> i.MX8QXP, i.MX8MP and i.MX8ULP.
> 
> Currently it is able to resolve addresses between DSP and main CPU,
> start and stop the processor, suspend and resume.
> 
> The communication between DSP and main CPU is based on mailbox, there
> are three mailbox channels (tx, rx, rxdb).
> 
> This driver was tested on NXP i.MX8QM, i.MX8QXP, i.MX8MP and i.MX8ULP.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
> ---
>  drivers/remoteproc/Kconfig         |   11 +
>  drivers/remoteproc/Makefile        |    1 +
>  drivers/remoteproc/imx_dsp_rproc.c | 1206 ++++++++++++++++++++++++++++
>  3 files changed, 1218 insertions(+)
>  create mode 100644 drivers/remoteproc/imx_dsp_rproc.c
>

[...]

> +
> +/**
> + * imx_dsp_attach_pm_domains() - attach the power domains
> + * @priv: private data pointer
> + *
> + * On i.MX8QM and i.MX8QXP there is multiple power domains
> + * required, so need to link them.
> + */
> +static int imx_dsp_attach_pm_domains(struct imx_dsp_rproc *priv)
> +{
> +	struct device *dev = priv->rproc->dev.parent;
> +	int ret, i;
> +
> +	priv->num_domains = of_count_phandle_with_args(dev->of_node,
> +						       "power-domains",
> +						       "#power-domain-cells");
> +
> +	/* If only one domain, then no need to link the device */
> +	if (priv->num_domains <= 1)
> +		return 0;
> +
> +	priv->pd_dev = devm_kmalloc_array(dev, priv->num_domains,
> +					  sizeof(*priv->pd_dev),
> +					  GFP_KERNEL);
> +	if (!priv->pd_dev)
> +		return -ENOMEM;
> +
> +	priv->pd_dev_link = devm_kmalloc_array(dev, priv->num_domains,
> +					       sizeof(*priv->pd_dev_link),
> +					       GFP_KERNEL);
> +	if (!priv->pd_dev_link)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < priv->num_domains; i++) {
> +		priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
> +		if (IS_ERR(priv->pd_dev[i])) {
> +			ret = PTR_ERR(priv->pd_dev[i]);
> +			goto detach_pm;
> +		}

I have pointed a problem with the error handling in the above during the
previous review and it was not addressed.

> +
> +		/*
> +		 * device_link_add will check priv->pd_dev[i], if it is
> +		 * NULL, then will break.
> +		 */
> +		priv->pd_dev_link[i] = device_link_add(dev,
> +						       priv->pd_dev[i],
> +						       DL_FLAG_STATELESS |
> +						       DL_FLAG_PM_RUNTIME);
> +		if (!priv->pd_dev_link[i]) {
> +			dev_pm_domain_detach(priv->pd_dev[i], false);
> +			ret = -EINVAL;
> +			goto detach_pm;
> +		}
> +	}
> +
> +	return 0;
> +
> +detach_pm:
> +	while (--i >= 0) {
> +		device_link_del(priv->pd_dev_link[i]);
> +		dev_pm_domain_detach(priv->pd_dev[i], false);
> +	}
> +
> +	return ret;
> +}
> +