[PATCH v5 1/3] ARM: mxs: add GPMI-NFC support for imx23/imx28

Hi,

Arnd Bergmann writes:

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 {
+	/* 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.

NO! I strongly object that. mxs_iomux_setup_multiple_pads() is a
platform specific function and has no business inside a device driver
that should be platform agnostic.
Consider the same controller being part of a different SoC that
requires you to call mxs_iomux_v2_setup_multiple_pads() instead. You
would then have to check for the SoC type inside the driver to find
the right function to call which is quite obscene.

I would rather live with the iomux statically configured in the
platform init code than having direct calls into platform specific
code from device drivers.


Lothar Wa?mann
-- 
___________________________________________________________

Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen
Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10
Gesch?ftsf?hrer: Matthias Kaussen
Handelsregistereintrag: Amtsgericht Aachen, HRB 4996

www.karo-electronics.de | info at karo-electronics.de
___________________________________________________________