Re: [PATCH v2 3/3] fpga: zynqmp-fpga: Adds status interface

[Xu Yilun]

On Tue, Jun 21, 2022 at 02:58:33PM +0530, Nava kishore Manne wrote:
> Adds status interface for zynqmp-fpga, It's a read only
> interface which allows the user to get the PL status.
> 
> Usage:
> To read the PL configuration status
>         cat /sys/class/fpga_manager/<fpga>/status
> 
> Signed-off-by: Nava kishore Manne <nava.manne@xxxxxxxxxx>
> ---
> Changes for v2:
>               - Updated status messages handling logic as suggested by Xu Yilun.
> 
>  drivers/fpga/zynqmp-fpga.c | 53 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> index c60f20949c47..e194bba91d3f 100644
> --- a/drivers/fpga/zynqmp-fpga.c
> +++ b/drivers/fpga/zynqmp-fpga.c
> @@ -14,6 +14,19 @@
>  
>  /* Constant Definitions */
>  #define IXR_FPGA_DONE_MASK	BIT(3)
> +#define READ_DMA_SIZE		256U
> +
> +/* Error Register */
> +#define IXR_FPGA_ERR_CRC_ERR		BIT(0)
> +#define IXR_FPGA_ERR_SECURITY_ERR	BIT(16)
> +
> +/* Signal Status Register. For details refer ug570 */
> +#define IXR_FPGA_END_OF_STARTUP		BIT(4)
> +#define IXR_FPGA_GST_CFG_B		BIT(5)
> +#define IXR_FPGA_INIT_B_INTERNAL	BIT(11)
> +#define IXR_FPGA_DONE_INTERNAL_SIGNAL	BIT(13)
> +
> +#define IXR_FPGA_CONFIG_STAT_OFFSET	7U
>  
>  /**
>   * struct zynqmp_fpga_priv - Private data structure
> @@ -77,8 +90,48 @@ static enum fpga_mgr_states zynqmp_fpga_ops_state(struct fpga_manager *mgr)
>  	return FPGA_MGR_STATE_UNKNOWN;
>  }
>  
> +static ssize_t zynqmp_fpga_ops_status(struct fpga_manager *mgr, char *buf)
> +{
> +	unsigned int *kbuf, reg_val;
> +	dma_addr_t dma_addr;
> +	ssize_t len = 0;
> +	int ret;
> +
> +	kbuf = dma_alloc_coherent(mgr->dev.parent, READ_DMA_SIZE,
> +				  &dma_addr, GFP_KERNEL);
> +	if (!kbuf)
> +		return -ENOMEM;
> +
> +	ret = zynqmp_pm_fpga_read(IXR_FPGA_CONFIG_STAT_OFFSET, dma_addr,
> +				  PM_FPGA_READ_CONFIG_REG, &reg_val);
> +	if (ret) {
> +		len += sprintf(buf + len, "firmware error\n");
> +		goto free_dmabuf;
> +	}
> +
> +	if (reg_val & IXR_FPGA_ERR_CRC_ERR)
> +		len += sprintf(buf + len, "reconfig CRC error\n");
> +	if (reg_val & IXR_FPGA_ERR_SECURITY_ERR)
> +		len += sprintf(buf + len, "reconfig security error\n");
> +	if (!(reg_val & IXR_FPGA_INIT_B_INTERNAL))
> +		len += sprintf(buf + len, "Device Initialization error\n");
> +	if (!(reg_val & IXR_FPGA_DONE_INTERNAL_SIGNAL))
> +		len += sprintf(buf + len, "Device internal signal error\n");
> +	if (!(reg_val & IXR_FPGA_GST_CFG_B))
> +		len += sprintf(buf + len,
> +			       "All I/Os are placed in High-Z state\n");
> +	if (!(reg_val & IXR_FPGA_END_OF_STARTUP))
> +		len += sprintf(buf + len, "Device sequence error\n");

Expressing multiple lines of data is discouraged, one value or an array
of values is OK. For more details, see
Documentation/filesystems/sysfs.rst

Thanks,
Yilun

> +
> +free_dmabuf:
> +	dma_free_coherent(mgr->dev.parent, READ_DMA_SIZE, buf, dma_addr);
> +
> +	return len;
> +}
> +
>  static const struct fpga_manager_ops zynqmp_fpga_ops = {
>  	.state = zynqmp_fpga_ops_state,
> +	.status = zynqmp_fpga_ops_status,
>  	.write_init = zynqmp_fpga_ops_write_init,
>  	.write = zynqmp_fpga_ops_write,
>  };
> -- 
> 2.25.1