Subject: [PATCH v2 3/4] remoteproc: Supply controller driver for ST's Remote Processors

From: [email-masked] (Nathan Lynch)
Date: Fri, 28 Aug 2015 11:24:20 -0500

On 08/28/2015 05:31 AM, Lee Jones wrote:
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index 28c711f..72e97d7 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -77,4 +77,13 @@ config DA8XX_REMOTEPROC
>  	  It's safe to say n here if you're not interested in multimedia
>  	  offloading.
>  
> +config ST_REMOTEPROC
> +	tristate "ST remoteproc support"
> +	depends on ARCH_STI
> +	select REMOTEPROC
> +	help
> +	  Say y here to support ST's adjunct processors via the remote
> +	  processor framework.
> +	  This can be either built-in or a loadable module.
> +

The code uses reset_control_* APIs, so this should depend on
RESET_CONTROLLER, no?

> +/*
> + * ST's Remote Processor Control Driver
> + *
> + * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
> + *
> + * Author: Ludovic Barre <[email-masked]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2, or (at your option)
> + * any later version.
> + */

OK, but:

> +MODULE_LICENSE("GPL v2");

These are not in agreement.  You want "GPL" for MODULE_LICENSE if you
intend v2 or later.

> +static int st_rproc_stop(struct rproc *rproc)
> +{
> +	struct st_rproc *st_rproc = rproc->priv;
> +	int ret, err = 0;
> +
> +	if (st_rproc->config->sw_reset) {
> +		ret = reset_control_assert(st_rproc->sw_reset);
> +		if (ret)
> +			dev_err(&rproc->dev, "Failed to assert S/W Reset\n");
> +	}
> +
> +	if (st_rproc->config->pwr_reset) {
> +		err = reset_control_assert(st_rproc->pwr_reset);
> +		if (err)
> +			dev_err(&rproc->dev, "Failed to assert Power Reset\n");
> +	}
> +
> +	clk_disable(st_rproc->clk);
> +
> +	return ret ?: err;
> +}

Sorry, but I think this is a stylistically inadequate response to my
earlier comments.  At least name the status variables sw_ret and pwr_ret
or something.  And it looks like ret could be used uninitialized.

Also, do you want to unconditionally call clk_disable even if you've
encountered errors?

> +static int st_rproc_start(struct rproc *rproc)
> +{
> +	struct st_rproc *st_rproc = rproc->priv;
> +	int err;
> +
> +	regmap_update_bits(st_rproc->boot_base, st_rproc->boot_offset,
> +			   st_rproc->config->bootaddr_mask, rproc->bootaddr);
> +
> +	err = clk_enable(st_rproc->clk);
> +	if (err) {
> +		dev_err(&rproc->dev, "Failed to enable clock\n");
> +		return err;
> +	}
> +
> +	if (st_rproc->config->sw_reset) {
> +		err = reset_control_deassert(st_rproc->sw_reset);
> +		if (err) {
> +			dev_err(&rproc->dev, "Failed to deassert S/W Reset\n");
> +			return err;
> +		}
> +	}
> +
> +	if (st_rproc->config->pwr_reset) {
> +		err = reset_control_deassert(st_rproc->pwr_reset);
> +		if (err) {
> +			dev_err(&rproc->dev, "Failed to deassert Power Reset\n");
> +			return err;
> +		}
> +	}
> +
> +	dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
> +
> +	return 0;
> +}

Does this want to unwind any of its operations if it encounters a failure?