Hello,

On Thu, Jun 30, 2011 at 03:55:19PM +0200, Arnd Bergmann wrote:

On Thursday 30 June 2011, Huang Shijie wrote:

quoted

add GPMI-NFC support for imx23 and imx28.

Signed-off-by: Huang Shijie <redacted>

quoted

+/**
+ * struct gpmi_nfc_platform_data - GPMI NFC driver platform data.
+ *
+ * This structure communicates platform-specific information to the GPMI NFC
+ * driver that can't be expressed as resources.
+ *
+ * @platform_init:           A pointer to a function the driver will call to
+ *                           initialize the platform (e.g., set up the pin mux).
+ * @platform_exit:           A pointer to a function the driver will call to
+ *                           exit the platform (e.g., free pins).
+ * @min_prop_delay_in_ns:    Minimum propagation delay of GPMI signals to and
+ *                           from the NAND Flash device, in nanoseconds.
+ * @max_prop_delay_in_ns:    Maximum propagation delay of GPMI signals to and
+ *                           from the NAND Flash device, in nanoseconds.
+ * @max_chip_count:          The maximum number of chips for which the driver
+ *                           should configure the hardware. This value most
+ *                           likely reflects the number of pins that are
+ *                           connected to a NAND Flash device. If this is
+ *                           greater than the SoC hardware can support, the
+ *                           driver will print a message and fail to initialize.
+ * @partitions:              An optional pointer to an array of partition
+ *                           descriptions.
+ * @partition_count:         The number of elements in the partitions array.
+ */
+struct gpmi_nfc_platform_data {
+	/* SoC hardware information. */
+	int		(*platform_init)(void);
+	void		(*platform_exit)(void);
+
+	/* NAND Flash information. */
+	unsigned int	min_prop_delay_in_ns;
+	unsigned int	max_prop_delay_in_ns;
+	unsigned int	max_chip_count;
+
+	/* Medium information. */
+	struct mtd_partition *partitions;
+	unsigned	partition_count;
+};

When adding new infrastructure, always keep in mind how you want it to look
after the device tree conversion. The partitions and min/max_* are easily covered
with that, but the init/exit function pointers are somewhat problematic.

Fortunately, you don't really require these functions for this driver. The _exit
function is completely unused, so just get rid of it.

The init function is used only to set up iomux, so the logical replacement is
a pointer to the iomux data, and calling mxs_iomux_setup_multiple_pads
directly from the driver.

Why not put the iomux stuff into the per-machine table and get rid of
the init callback, too?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |