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

From: Xu Yilun
Date: Tue Jun 28 2022 - 04:48:55 EST


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