[PATCH linux 2/5] spi: aspeed: Introduce a "windows" device attribute

[Cédric Le Goater]

On 6/28/22 18:20, Cédric Le Goater wrote:
> This dumps the mapping windows, or decoding ranges, of all devices
> possibly attached of the controller.

We might want to change the name of the sysfs attribute to "ranges" or
"decoding-ranges" to be in sync with the new DT property.

C.

> Signed-off-by: Cédric Le Goater <clg at kaod.org>
> ---
>   drivers/spi/spi-aspeed-smc.c | 43 ++++++++++++++++++++++++++++++++++++
>   1 file changed, 43 insertions(+)
> 
> diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
> index 5a995b5653f1..1611c354c31f 100644
> --- a/drivers/spi/spi-aspeed-smc.c
> +++ b/drivers/spi/spi-aspeed-smc.c
> @@ -382,6 +382,7 @@ static const char *aspeed_spi_get_name(struct spi_mem *mem)
>   
>   struct aspeed_spi_window {
>   	u32 cs;
> +	u32 reg;
>   	u32 offset;
>   	u32 size;
>   };
> @@ -396,6 +397,7 @@ static void aspeed_spi_get_windows(struct aspeed_spi *aspi,
>   	for (cs = 0; cs < aspi->data->max_cs; cs++) {
>   		reg_val = readl(aspi->regs + CE0_SEGMENT_ADDR_REG + cs * 4);
>   		windows[cs].cs = cs;
> +		windows[cs].reg = reg_val;
>   		windows[cs].size = data->segment_end(aspi, reg_val) -
>   			data->segment_start(aspi, reg_val);
>   		windows[cs].offset = data->segment_start(aspi, reg_val) - aspi->ahb_base_phy;
> @@ -712,6 +714,41 @@ static void aspeed_spi_enable(struct aspeed_spi *aspi, bool enable)
>   		aspeed_spi_chip_enable(aspi, cs, enable);
>   }
>   
> +static int windows_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> +	struct aspeed_spi *aspi = dev_get_drvdata(dev);
> +	struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS] = { 0 };
> +	u32 cs;
> +	int len = 0;
> +
> +	if (aspi->data == &ast2400_spi_data)
> +		return 0;
> +
> +	aspeed_spi_get_windows(aspi, windows);
> +
> +	len += sysfs_emit_at(buf, len, "     offset     size       register\n");
> +	for (cs = 0; cs < aspi->data->max_cs; cs++) {
> +		if (!windows[cs].reg)
> +			len += sysfs_emit_at(buf, len, "CE%d: disabled\n", cs);
> +		else
> +			len += sysfs_emit_at(buf, len, "CE%d: 0x%.8x 0x%.8x 0x%x\n", cs,
> +					     windows[cs].offset, windows[cs].size,
> +					     windows[cs].reg);
> +	}
> +	return len;
> +}
> +
> +static DEVICE_ATTR_RO(windows);
> +
> +static struct attribute *aspeed_spi_attributes[] = {
> +	&dev_attr_windows.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group aspeed_spi_attribute_group = {
> +	.attrs = aspeed_spi_attributes
> +};
> +
>   static int aspeed_spi_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
> @@ -784,6 +821,12 @@ static int aspeed_spi_probe(struct platform_device *pdev)
>   		dev_err(&pdev->dev, "spi_register_controller failed\n");
>   		goto disable_clk;
>   	}
> +
> +	ret = devm_device_add_group(&pdev->dev, &aspeed_spi_attribute_group);
> +	if (ret) {
> +		dev_err(&pdev->dev, "cannot create attribute group\n");
> +		goto disable_clk;
> +	}
>   	return 0;
>   
>   disable_clk: