Re: [PATCH v2 2/2] spi: loongson: add bus driver for the loongson spi controller

From: Mark Brown <broonie@kernel.org>
To: Yinbo Zhu <zhuyinbo@loongson.cn>
Cc: Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	linux-spi@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, Jianmin Lv <lvjianmin@loongson.cn>,
	wanghongliang@loongson.cn, Liu Peibao <liupeibao@loongson.cn>,
	loongson-kernel@lists.loongnix.cn
Subject: Re: [PATCH v2 2/2] spi: loongson: add bus driver for the loongson spi controller
Date: Fri, 17 Mar 2023 16:26:45 +0000	[thread overview]
Message-ID: <68b6034f-8305-4854-a4c9-962be988ade7@sirena.org.uk> (raw)
In-Reply-To: <20230317082950.12738-3-zhuyinbo@loongson.cn>

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On Fri, Mar 17, 2023 at 04:29:50PM +0800, Yinbo Zhu wrote:

> +static int loongson_spi_update_state(struct loongson_spi *loongson_spi,
> +				     struct spi_device *spi, struct spi_transfer *t)
> +{

...

> +		loongson_spi->hz = hz;
> +		loongson_spi->spcr = div_tmp & 3;
> +		loongson_spi->sper = (div_tmp >> 2) & 3;
> +		val = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG);

This is writing to general chip registers, apparently not per chip
select ones.

> +static int loongson_spi_setup(struct spi_device *spi)
> +{
> +	struct loongson_spi *loongson_spi;

> +	spin_lock(&loongson_spi->lock);
> +	loongson_spi_update_state(loongson_spi, spi, NULL);

As IIRC I mentioned last time setup() might be called while other
transfers are happening and therefore shouldn't affect parallel
operations on other devices.

> +static const struct of_device_id loongson_spi_id_table[] = {
> +	{ .compatible = "loongson,ls2k-spi", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, loongson_spi_id_table);
> +
> +static struct platform_driver loongson_spi_driver = {
> +	.probe = loongson_spi_platform_probe,
> +	.driver	= {
> +		.name	= "loongson-spi",
> +		.owner	= THIS_MODULE,
> +		.bus = &platform_bus_type,
> +		.pm = &loongson_spi_dev_pm_ops,
> +		.of_match_table = loongson_spi_id_table,
> +	},
> +};
> +
> +#ifdef CONFIG_PCI
> +static int loongson_spi_pci_register(struct pci_dev *pdev,
> +			const struct pci_device_id *ent)

Again as I said last time the two buses should probably be separate
modules.

Otherwise this looks fine.

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