[PATCH 3/4 v4] mailbox: Enable BCM2835 mailbox support

[Lee Jones]

On Thu, 12 Mar 2015, Eric Anholt wrote:

> From: Lubomir Rintel <lkundrak at v3.sk>
> 
> Implement BCM2835 mailbox support as a device registered with the
> general purpose mailbox framework. Implementation based on commits by
> Lubomir Rintel [1], Suman Anna and Jassi Brar [2] on which to base the
> implementation.
> 
> [1] http://lists.infradead.org/pipermail/linux-rpi-kernel/2013-April/000528.html
> [2] http://lists.infradead.org/pipermail/linux-rpi-kernel/2013-May/000546.html
> 
> Signed-off-by: Lubomir Rintel <lkundrak at v3.sk>
> Signed-off-by: Craig McGeachie <slapdau at yahoo.com.au>
> Signed-off-by: Suman Anna <s-anna at ti.com>
> Signed-off-by: Jassi Brar <jassisinghbrar at gmail.com>
> Signed-off-by: Eric Anholt <eric at anholt.net>
> Cc: Jassi Brar <jassisinghbrar at gmail.com>
> Acked-by: Lee Jones <lee.jones at linaro.org>
> ---
> 
> 
> v2: Squashed Craig's work for review, carried over to new version of
>     Mailbox framework (changes by Lubomir)
> 
> v3: Fix multi-line comment style.  Refer to the documentation by
>     filename.  Only declare one MODULE_AUTHOR.  Alphabetize includes.
>     Drop some excessive dev_dbg()s (changes by anholt).
> 
> v4: Use the new bcm2835_peripheral_read_workaround(), drop the

Can you explain to me why this is required (and don't just point me in
the direction of the other patch ;) ).  You appear to be using the
non-relaxed variants of readl and writel, which already do memory
barriers, so I'm a little perplexed as to how the problem can arise.

>     unnecessary wmb()s, make the messages be a pointer to u32, rather
>     than u32-cast-as-pointer, fold in small static functions, drop
>     extra error messages, clean up sizeof() arg for malloc, disable
>     interrupts on unload.
> 
>  drivers/mailbox/Kconfig           |   8 ++
>  drivers/mailbox/Makefile          |   2 +
>  drivers/mailbox/bcm2835-mailbox.c | 259 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 269 insertions(+)
>  create mode 100644 drivers/mailbox/bcm2835-mailbox.c