quoted

+ SUNXI_PIN(SUNXI_PINCTRL_PIN(F, 0),
+  SUNXI_FUNCTION(0x0, "gpio_in"),
+  SUNXI_FUNCTION(0x1, "gpio_out"),
+  SUNXI_FUNCTION(0x2, "mmc0"),  /* D1 */
+  SUNXI_FUNCTION(0x3, "jtag"),  /* MS1 */
+  SUNXI_FUNCTION(0x4, "jtag"),  /* MS_GPU */

We should use another name here, since the code will just pick the first one and
ignore the second. What about jtag-gpu?

The underscores are used in front, so changing it to jtag_gpu may be more consistent.

quoted

+ SUNXI_PIN(SUNXI_PINCTRL_PIN(B, 7),
+  SUNXI_FUNCTION(0x0, "gpio_in"),
+  SUNXI_FUNCTION(0x1, "gpio_out"),
+  SUNXI_FUNCTION(0x2, "spdif"),  /* DIN */
+  SUNXI_FUNCTION(0x3, "i2s0"),  /* DOUT0 */
+  SUNXI_FUNCTION(0x4, "i2s0"),  /* DIN1 */

I guess the second one would be i2s1?

No, each i2s may have many inputs and outputs. 

 SUNXI_PIN(SUNXI_PINCTRL_PIN(H, 19),
     SUNXI_FUNCTION(0x0, "gpio_in"),
              SUNXI_FUNCTION(0x1, "gpio_out"),
              SUNXI_FUNCTION(0x2, "cir0"),          /* IN */
              SUNXI_FUNCTION(0x3, "i2s3_dout3"),       /* DOUT3 */
              SUNXI_FUNCTION(0x4, "i2s3_din3"),       /* DIN3 */
              SUNXI_FUNCTION(0x5, "ledc"),
              SUNXI_FUNCTION_IRQ_BANK(0x6, 6, 19)),

Considering that the same pin has multiple same functions, 
so add a suffix, like i2s3_dout3 and i2s3_din3?   

Or specify muxsel in the device tree may be another solution.

quoted

+ SUNXI_PIN(SUNXI_PINCTRL_PIN(H, 2),
+  SUNXI_FUNCTION(0x0, "gpio_in"),
+  SUNXI_FUNCTION(0x1, "gpio_out"),
+  SUNXI_FUNCTION(0x2, "i2c1"),  /* SCK */
+  SUNXI_FUNCTION(0x3, "cpu"),  /* CUR_W */

What is "cpu" supposed to be?

As far as I know, this is a function that has never been used.
The hardware guy said that it can be used to control the CPU to reduce the current.

Thx,
Yangtao