Commit Graph

7 Commits

Author SHA1 Message Date
Magnus Damm
69edbba002 sh: use gpiolib
This patch updates the SuperH gpio code to make use of gpiolib. The
gpiolib callbacks get() and set() are lockless, but we use our own
spinlock for the other operations to make sure hardware register
bitfield accesses stay atomic.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-27 14:49:10 +09:00
Magnus Damm
3292094e88 sh: lockless gpio_set_value()
This patch optimizes the gpio data register handling for gpio_set_value().

Instead of using the good old spinlock-plus-read-modify-write strategy
we now use a shadow register and atomic operations.

This improves the bitbanging mmc performance on Migo-R from 26 Kbytes/s
to 40 Kbytes/s.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-27 14:49:10 +09:00
Magnus Damm
0fc64cc0a2 sh: lockless gpio_get_value()
This patch separates the register read and write functions to
allow lockless gpio_get_value().

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-27 14:49:09 +09:00
Magnus Damm
18801be7f8 sh: make gpio_get/set_value() O(1)
This patch modifies the table based SuperH gpio implementation to
make use of direct table lookups. With this change the functions
gpio_get_value() and gpio_set_value() are O(1).

Tested on Migo-R using bitbanging mmc. Performance is improved from
11 KBytes/s to 26 Kbytes/s.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-27 14:49:09 +09:00
Magnus Damm
42eed42bac sh: improve pinmux support for single direction pins
This patch improves the support for gpio pins that are hard wired
to either input or output and lack control register association.
A special force enum id is used to allow use without control
register but still mark the gpio pin as input or output.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-10-22 18:34:16 +09:00
Magnus Damm
ed0b2ef55a sh: Update gpio_set_value() pin value handling
This patch updates the pinmux code to use the boolean value for
the function gpio_set_value(). Without this patch values other
than 0 and 1 will result in incorrect GPIO settings.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-10-21 21:41:23 +09:00
Magnus Damm
2967dab1ae sh: GPIO and pinmux base code
This patch adds gpio code together with the pinmux table parser.
In the future we should optimize this and switch back to gpiolib.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-10-20 10:33:50 +09:00