On Thu, Aug 22, 2019 at 9:25 PM Scott Branden scott.branden@broadcom.com wrote:
Add user space api for bcm-vk driver.
+struct vk_metadata {
/* struct version, always backwards compatible */__u32 version;/* Version 0 fields */__u32 card_status;+#define VK_CARD_STATUS_FASTBOOT_READY BIT(0) +#define VK_CARD_STATUS_FWLOADER_READY BIT(1)
__u32 firmware_version;__u32 fw_status;/* End version 0 fields */__u64 reserved[14];/* Total of 16*u64 for all versions */+};
I'd suggest getting rid of the API version fields, just leave the version 0 fields here and add a new structure + ioctl if you need other fields
Versioning usually just adds complexity and is hard to get right.
+struct vk_access {
__u8 barno; /* BAR number to use */__u8 type; /* Type of access */+#define VK_ACCESS_READ 0 +#define VK_ACCESS_WRITE 1
__u32 len; /* length of data */__u64 offset; /* offset in BAR */__u32 *data; /* where to read/write data to */+};
The pointer in the last member makes the structure incompatible between 32-bit and 64-bit user space. You could work around that using a __u64 member and turning that into a pointer using the u64_to_user_ptr() macro in the driver in a portable way.
However, since this seems to be a read/write type interface, maybe it's better to just use read/write file operations.
I also wonder if the interface should be on a higher abstraction level here.
Arnd