Re: [RFC PATCH 01/06] input/rmi4: Public header and documentation

From: Christopher Heiny
Date: Tue Oct 23 2012 - 18:38:59 EST

On 10/11/2012 01:20 AM, Dmitry Torokhov wrote:
On Fri, Oct 05, 2012 at 09:09:58PM -0700, Christopher Heiny wrote:
+ int (*write_block)(struct rmi_phys_device *phys, u16 addr, u8 *buf,
+ int len);
+ int (*read_block)(struct rmi_phys_device *phys, u16 addr, u8 *buf,
+ int len);

If you declare your buffer as [const] void * instead of u8 * I think you
will be able to get rid of most of your unions.

Good point. We'll explore that. If you see it in the next patch, you'll know it worked out.

+ * Helper fn to convert a byte array representing a 16 bit value in the RMI
+ * endian-ness to a 16-bit value in the native processor's specific endianness.
+ * We don't use ntohs/htons here because, well, we're not dealing with
+ * a pair of 16 bit values. Casting dest to u16* wouldn't work, because
+ * that would imply knowing the byte order of u16 in the first place. The
+ * same applies for using shifts and masks.
+ */
+static inline u16 batohs(u8 *src)
+ return src[1] * 0x100 + src[0];
+ * Helper function to convert a 16 bit value (in host processor endianess) to
+ * a byte array in the RMI endianess for u16s. See above comment for
+ * why we dont us htons or something like that.
+ */
+static inline void hstoba(u8 *dest, u16 src)
+ dest[0] = src % 0x100;
+ dest[1] = src / 0x100;

These are not used anymore, right?

There are function drivers that we chose not to include that depend on these. We'll drop these from rmi.h until we're ready to submit those other function drivers.
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