linux/drivers/mmc
Haavard Skinnemoen 965ebf33ea atmel-mci: support multiple mmc slots
The Atmel MCI controller can drive multiple cards through separate sets
of pins, but only one at a time. This patch adds support for
multiplexing access to the controller so that multiple card slots can be
used as if they were hooked up to separate mmc controllers.

The atmel-mci driver registers each slot as a separate mmc_host. Both
access the same common controller state, but they also have some state
on their own for card detection/write protect handling, and separate
shadows of the MR and SDCR registers.

When one of the slots receives a request from the mmc core, the common
controller state is checked. If it's idle, the request is submitted
immediately. If not, the request is added to a queue. When a request is
done, the queue is checked and if there is a queued request, it is
submitted before the completion callback is called.

This patch also includes a few cleanups and fixes, including a locking
overhaul. I had to change the locking extensively in any case, so I
might as well try to get it right. The driver no longer takes any
irq-safe locks, which may or may not improve the overall system
performance.

This patch also adds a bit of documentation of the internal data
structures.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-10-05 20:39:21 +02:00
..
card Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc 2008-09-21 12:38:45 -07:00
core mmc: properly iterate over sg list in debug check 2008-08-01 19:03:37 +02:00
host atmel-mci: support multiple mmc slots 2008-10-05 20:39:21 +02:00
Kconfig [S390] Kconfig: menus with depends on HAS_IOMEM. 2007-05-10 15:46:07 +02:00
Makefile mmc: Move core functions to subdir 2007-05-01 13:04:18 +02:00