Re: [PATCH v8 09/11] reset: Add Nuvoton ma35d1 reset driver support

[Philipp Zabel <p.zabel@pengutronix.de>]

Hi Jacky,

On Tue, Apr 25, 2023 at 10:24:16AM +0000, Jacky Huang wrote:
> From: Jacky Huang <ychuang3@nuvoton.com>
> 
> This driver supports individual IP reset for ma35d1. The reset
> control registers is a subset of system control registers.
> 
> Signed-off-by: Jacky Huang <ychuang3@nuvoton.com>
> ---
>  drivers/reset/Kconfig        |   6 +
>  drivers/reset/Makefile       |   1 +
>  drivers/reset/reset-ma35d1.c | 229 +++++++++++++++++++++++++++++++++++
[...]
> diff --git a/drivers/reset/reset-ma35d1.c b/drivers/reset/reset-ma35d1.c
> new file mode 100644
> index 000000000000..648b380becf7
> --- /dev/null
> +++ b/drivers/reset/reset-ma35d1.c
> @@ -0,0 +1,229 @@
[...]
> +static int ma35d1_reset_update(struct reset_controller_dev *rcdev,
> +			       unsigned long id, bool assert)
> +{
> +	u32 reg;
> +	struct ma35d1_reset_data *data = container_of(rcdev,
> +						      struct ma35d1_reset_data,
> +						      rcdev);
> +
> +	reg = readl_relaxed(data->base + ma35d1_reset_map[id].reg_ofs);
> +	if (assert)
> +		reg |= BIT(ma35d1_reset_map[id].bit);
> +	else
> +		reg &= ~(BIT(ma35d1_reset_map[id].bit));
> +	writel_relaxed(reg, data->base + ma35d1_reset_map[id].reg_ofs);

This is missing a spinlock to protect the read-modify-write cycle from
simultaneous updates.

[...]
> +static int ma35d1_reset_probe(struct platform_device *pdev)
> +{
> +	int err;
> +	struct device *dev = &pdev->dev;
> +	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	struct ma35d1_reset_data *reset_data;
> +
> +	if (!pdev->dev.of_node) {
> +		dev_err(&pdev->dev, "Device tree node not found\n");
> +		return -EINVAL;
> +	}
> +
> +	reset_data = devm_kzalloc(dev, sizeof(*reset_data), GFP_KERNEL);
> +	if (!reset_data)
> +		return -ENOMEM;
> +
> +	reset_data->base = devm_ioremap_resource(&pdev->dev, res);

You could use devm_platform_ioremap_resource() here.

regards
Philipp