[PATCH v3 6/8] drivers/soc: xdma: Add debugfs entries

[Eddie James]

Add debugfs entries for the relevant XDMA engine registers and for
dumping the AST2500 reserved memory space.

Signed-off-by: Eddie James <eaja...@linux.ibm.com>
---
 drivers/soc/aspeed/aspeed-xdma.c | 94 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/drivers/soc/aspeed/aspeed-xdma.c b/drivers/soc/aspeed/aspeed-xdma.c
index ddd5e1e..ea42dbe 100644
--- a/drivers/soc/aspeed/aspeed-xdma.c
+++ b/drivers/soc/aspeed/aspeed-xdma.c
@@ -145,6 +145,12 @@ struct aspeed_xdma {
 
        char pcidev[4];
        struct miscdevice misc;
+       struct dentry *debugfs_dir;
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+       struct debugfs_regset32 regset;
+       struct debugfs_reg32 regs[XDMA_NUM_DEBUGFS_REGS];
+#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */
 };
 
 struct aspeed_xdma_client {
@@ -603,6 +609,90 @@ static int aspeed_xdma_init_mem(struct aspeed_xdma *ctx, 
u32 conf)
        return rc;
 }
 
+static ssize_t aspeed_xdma_debugfs_vga_read(struct file *file,
+                                           char __user *buf, size_t len,
+                                           loff_t *offset)
+{
+       int rc = -ENOMEM;
+       struct inode *inode = file_inode(file);
+       struct aspeed_xdma *ctx = inode->i_private;
+       loff_t offs = *offset;
+       void *tmp;
+       void __iomem *vga;
+
+       if (len + offs > ctx->vga_size) {
+               if (offs < ctx->vga_size)
+                       len = ctx->vga_size - offs;
+               else
+                       return 0;
+       }
+
+       vga = ioremap(ctx->vga_phys, ctx->vga_size);
+       if (!vga)
+               return rc;
+
+       tmp = kzalloc(len, GFP_KERNEL);
+       if (!tmp)
+               goto unmap;
+
+       memcpy_fromio(tmp, vga + offs, len);
+
+       rc = copy_to_user(buf, tmp, len);
+       if (rc)
+               goto free;
+
+       *offset = offs + len;
+       rc = len;
+
+free:
+       kfree(tmp);
+
+unmap:
+       iounmap(vga);
+
+       return rc;
+}
+
+static const struct file_operations aspeed_xdma_debugfs_vga_fops = {
+       .owner  = THIS_MODULE,
+       .llseek = generic_file_llseek,
+       .read   = aspeed_xdma_debugfs_vga_read,
+};
+
+static void aspeed_xdma_init_debugfs(struct aspeed_xdma *ctx)
+{
+       if (!IS_ENABLED(CONFIG_DEBUG_FS))
+               return;
+
+       ctx->debugfs_dir = debugfs_create_dir(DEVICE_NAME, NULL);
+       if (IS_ERR(ctx->debugfs_dir)) {
+               dev_warn(ctx->dev, "Failed to create debugfs directory.\n");
+               return;
+       }
+
+       debugfs_create_file("vga", 0444, ctx->debugfs_dir, ctx,
+                           &aspeed_xdma_debugfs_vga_fops);
+
+       ctx->regs[0].name = "addr";
+       ctx->regs[0].offset = XDMA_BMC_CMD_QUEUE_ADDR;
+       ctx->regs[1].name = "endp";
+       ctx->regs[1].offset = XDMA_BMC_CMD_QUEUE_ENDP;
+       ctx->regs[2].name = "writep";
+       ctx->regs[2].offset = XDMA_BMC_CMD_QUEUE_WRITEP;
+       ctx->regs[3].name = "readp";
+       ctx->regs[3].offset = XDMA_BMC_CMD_QUEUE_READP;
+       ctx->regs[4].name = "control";
+       ctx->regs[4].offset = XDMA_CTRL;
+       ctx->regs[5].name = "status";
+       ctx->regs[5].offset = XDMA_STATUS;
+
+       ctx->regset.regs = ctx->regs;
+       ctx->regset.nregs = XDMA_NUM_DEBUGFS_REGS;
+       ctx->regset.base = ctx->base;
+
+       debugfs_create_regset32("regs", 0444, ctx->debugfs_dir, &ctx->regset);
+}
+
 static int aspeed_xdma_change_pcie_conf(struct aspeed_xdma *ctx, u32 conf)
 {
        int rc;
@@ -777,6 +867,8 @@ static int aspeed_xdma_probe(struct platform_device *pdev)
 
        device_create_file(dev, &dev_attr_pcidev);
 
+       aspeed_xdma_init_debugfs(ctx);
+
        return 0;
 }
 
@@ -784,6 +876,8 @@ static int aspeed_xdma_remove(struct platform_device *pdev)
 {
        struct aspeed_xdma *ctx = platform_get_drvdata(pdev);
 
+       debugfs_remove_recursive(ctx->debugfs_dir);
+
        device_remove_file(ctx->dev, &dev_attr_pcidev);
 
        misc_deregister(&ctx->misc);
-- 
1.8.3.1