Commit Graph

5 Commits

Author SHA1 Message Date
Linus Walleij
cc2a73a4a9 pinctrl: pxa2xx: export symbols
The pxa2xxx fails some automated builds because of unexported
symbols.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-03-09 09:10:02 +07:00
Robert Jarzmik
e670b29815 pinctrl: pxa: pxa2xx: add pin control skeleton
The wrong free functions were used to release temporary buffers.

This didn't show up in the normal driver's life. Yet in suspend to RAM,
the managed resource list is walked, and as memory was released, the
list is corrupted and make the kernel Oops.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-15 14:07:06 +01:00
Robert Jarzmik
aedf08b664 pinctrl: pxa: pxa2xx: add pin configuration support
Add pin configuration for pxa2xx architectures. PXA doesn't provide any
bias, push, pull capabilities. The only capability is to set a state for
the pins when the platform enter sleep or deep sleep mode.

The state of a pin is set by :
 - whether the GPIO direction was input or output
 - if it is output, a register set programs whether the pin should be
   held to ground or VccIO

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-10 16:12:35 +01:00
Robert Jarzmik
d530ef9b88 pinctrl: pxa: pxa2xx: add pin muxing
The driver is inspired from the sunxi driver. The pxa architecture
specificities leading to the driver are :
 - each pin has 8 possible alternate functions
 - 4 of these are output kind
 - 4 of these are input kind
 - there is always a "gpio input" and "gpio output" function
 - the function matrix is very scattered :
   - some functions can be found on 5 different pads
   - the number of functions is greater than the number of pins
   - there is no "topology" grouping of pins (such as all SPI in one
     corner of the die)

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-10 16:11:35 +01:00
Robert Jarzmik
73317712d9 pinctrl: pxa: pxa2xx: add pin control skeleton
Add a pincontrol driver for pxa2xx architecture, encompassing all pxa25x
and pxa27x variants. This is only the pin muxing part of the driver.

One specific consideration is also the memory space (MMIO), which is
intertwined with the GPIO registers. To make things worse, the GPIO
direction register also affect pin muxing, as it chooses the "kind" of
pin, ie. the 4 output functions or 4 input functions.

The mapping between pinctrl notions and PXA Technical Reference Manual
is as follows :
 - a pin is obviously a pin
 - a group is also a pin, ie. group P101 is the pin 101
 - a mux function is an alternate function
   (ie. gpio-in, gpio-out, MMCLK, BTRTS, etc ...)

The individual architecture (pxa27x, pxa25x) instantiate a pin control
by providing a table of pins, each pin being provided a list of
PXA_FUNCTION (alternate functions).

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-12-10 16:10:16 +01:00