[PATCH arm/aspeed/ast2500 v2] eSPI: add ASPEED AST2500 eSPI driver to boot a host with PCH runs on eSPI

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Fri, 2018-02-23 at 15:04 +0800, Haiyue Wang wrote:
> When PCH works under eSPI mode, the PMC (Power Management Controller)
> in
> PCH is waiting for SUS_ACK from BMC after it alerts SUS_WARN. It is in
> dead loop if no SUS_ACK assert. This is the basic requirement for the
> BMC
> works as eSPI slave.

So, do we have an agreement that the driver should go in this shape w/o
interacting with SPI subsystem?

Also few comments below.

> +config ASPEED_ESPI_SLAVE

> +	depends on (ARCH_ASPEED || COMPILE_TEST) && REGMAP_MMIO

I would rather split this to two
	depends on REGMAP_MMIO
	depends on ARCH_ASPEED || COMPILE_TEST

> +	tristate "Aspeed ast2500 eSPI slave device driver"
> +	---help---
> +	  Control Aspeed ast2500 eSPI slave controller to handle
> event
> +	  which needs the firmware's processing.

> +#include <linux/of.h>

What exactly requires this header?

> +static int aspeed_espi_slave_probe(struct platform_device *pdev)
> +{
> +	struct aspeed_espi_slave_data *priv;
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	void __iomem *regs;
> +	int rc;
> +

> +	dev_set_name(dev, DEVICE_NAME);

Do this after checks and memory allocations.

> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	regs = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(regs))
> +		return PTR_ERR(regs);
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->map = devm_regmap_init_mmio(dev, regs,
> &espi_slave_regmap_cfg);
> +	if (IS_ERR(priv->map))
> +		return PTR_ERR(priv->map);
> +

> +static const struct of_device_id of_espi_slave_match_table[] = {
> +	{ .compatible = "aspeed,ast2500-espi-slave" },
> +	{ }
> +};

> +MODULE_DEVICE_TABLE(of, of_espi_slave_match_table);

This one should be closer to the struct of_device_id.

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy