Commit Graph

16 Commits

Author SHA1 Message Date
Andrew Jeffery
03ffb507c8 pinctrl: aspeed: Fix unused-const-variable warnings
Three video input signals suffered from a search/replace failure in
some copied code.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-04-11 09:47:44 +02:00
Rick Altherr
c825676b08 pinctrl: aspeed: Allow disabling Port D and Port E loopback mode
Port D and port E GPIO loopback modes are commonly enabled via hardware
straps for use with front-panel buttons.  When the BMC is powered
off or fails to boot, the front-panel buttons are directly connected to
the host chipset via the loopback to allow direct power-on and reset
control. Once the BMC has booted, the loopback mode must be disabled for
the BMC to take over control of host power-on and reset.

Disabling these loopback modes requires writing to the hardware strap
register which violates the current design of assuming the system
designer chose the strap settings for a specific reason and they should
be treated as read-only. Only the two bits of the strap register related
to these loopback modes are allowed to be written and comments have been
added to explain why.

Signed-off-by: Rick Altherr <raltherr@google.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-03-14 14:42:22 +01:00
Andrew Jeffery
8ccb6dc6e9 pinctrl: aspeed: g4: Fix mux configuration for GPIOs AA[4-7], AB[0-7]
Incorrect video output configuration bits were being tested on pins in
GPIO banks AA and AB for the ROM{8,16} mux functions. The ROM{8,16}
functions are the highest priority for the relevant pins and also the
default function, so we require the relevant video output configuration
be disabled to mux GPIO functionality. As the wrong bits were being
tested a GPIO export would succeed but leave the pin in an unresponsive
state (i.e. value updates were ignored).

This misbehaviour was discovered as part of extending the GPIO
controller's support to cover banks Y, Z, AA, AB and AC (AC in the case
of the g5 SoC).

Fixes: 6d329f14a7 ("pinctrl: aspeed-g4: Add mux configuration for all pins")
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26 14:42:39 +01:00
Andrew Jeffery
b75dd8722e pinctrl: aspeed: Fix kerneldoc return descriptions
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-12-28 01:23:10 +01:00
Andrew Jeffery
f1337856dd pinctrl: aspeed-g5: Add mux configuration for all pins
The patch introducing the g5 pinctrl driver implemented a smattering of
pins to flesh out the implementation of the core and provide bare-bones
support for some OpenPOWER platforms and the AST2500 evaluation board.
Now, update the bindings document to reflect the complete functionality
and implement the necessary pin configuration tables in the driver.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-12-28 01:21:23 +01:00
Andrew Jeffery
6d329f14a7 pinctrl: aspeed-g4: Add mux configuration for all pins
The patch introducing the g4 pinctrl driver implemented a smattering of
pins to flesh out the implementation of the core and provide bare-bones
support for some OpenPOWER platforms. Now, update the bindings document
to reflect the complete functionality and implement the necessary pin
configuration tables in the driver.

Cc: Timothy Pearson <tpearson@raptorengineering.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-12-27 23:17:23 +01:00
Andrew Jeffery
7d29ed88ac pinctrl: aspeed: Read and write bits in LPC and GFX controllers
The System Control Unit IP block in the Aspeed SoCs is typically where
the pinmux configuration is found, but not always. A number of pins
depend on state in one of LPC Host Control (LHC) or SoC Display
Controller (GFX) IP blocks, so the Aspeed pinmux drivers should have the
means to adjust these as necessary.

We use syscon to cast a regmap over the GFX and LPC blocks, which is
used as an arbitration layer between the relevant driver and the pinctrl
subsystem. The regmaps are then exposed to the SoC-specific pinctrl
drivers by phandles in the devicetree, and are selected during a mux
request by querying a new 'ip' member in struct aspeed_sig_desc.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-12-27 23:15:32 +01:00
Andrew Jeffery
a33547cc76 pinctrl-aspeed-g5: Never set SCU90[6]
If a pin depending on bit 6 in SCU90 is requested for GPIO, the export
will succeed but changes to the GPIO's value will not be accepted by the
hardware. This is because the pinmux driver has misconfigured the SCU by
writing 1 to the reserved bit.

The description of SCU90[6] from the datasheet is 'Reserved, must keep
at value ”0”'. The fix is to switch pinmux from the bit-flipping macro
to explicitly configuring the .enable and .disable values to zero.

The patch has been tested on an AST2500 EVB.

Fixes: 56e57cb6c0 (pinctrl: Add pinctrl-aspeed-g5 driver)
Reported-by: Uma Yadlapati <yadlapat@us.ibm.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-11-07 10:31:33 +01:00
Andrew Jeffery
8eb37aff76 pinctrl: aspeed-g5: Fix pin association of SPI1 function
The SPI1 function was associated with the wrong pins: The functions that
those pins provide is either an SPI debug or passthrough function
coupled to SPI1. Make the SPI1 mux function configure the relevant pins
and associate new SPI1DEBUG and SPI1PASSTHRU functions with the pins
that were already defined.

The notation used in the datasheet's multi-function pin table for the SoC is
often creative: in this case the SYS* signals are enabled by a single bit,
which is nothing unusual on its own, but in this case the bit was also
participating in a multi-bit bitfield and therefore represented multiple
functions. This fact was overlooked in the original patch.

Fixes: 56e57cb6c0 (pinctrl: Add pinctrl-aspeed-g5 driver)
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-18 14:36:12 +02:00
Andrew Jeffery
d3dbabe984 pinctrl: aspeed-g5: Fix GPIOE1 typo
This prevented C20 from successfully being muxed as GPIO.

Fixes: 56e57cb6c0 (pinctrl: Add pinctrl-aspeed-g5 driver)
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-18 14:36:11 +02:00
Andrew Jeffery
97e8c3f5e7 pinctrl: aspeed-g5: Fix names of GPID2 pins
Fixes simple typos in the initial commit. There is no behavioural
change.

Fixes: 56e57cb6c0 (pinctrl: Add pinctrl-aspeed-g5 driver)
Reported-by: Xo Wang <xow@google.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-18 14:36:11 +02:00
Andrew Jeffery
5366f1460c pinctrl: aspeed: "Not enabled" is a significant mux state
Consider a scenario with one pin P that has two signals A and B, where A
is defined to be higher priority than B: That is, if the mux IP is in a
state that would consider both A and B to be active on P, then A will be
the active signal.

To instead configure B as the active signal we must configure the mux so
that A is inactive. The mux state for signals can be described by
logical operations on one or more bits from one or more registers (a
"signal expression"), which in some cases leads to aliased mux states for
a particular signal. Further, signals described by multi-bit bitfields
often do not only need to record the states that would make them active
(the "enable" expressions), but also the states that makes them inactive
(the "disable" expressions). All of this combined leads to four possible
states for a signal:

         1. A signal is active with respect to an "enable" expression
         2. A signal is not active with respect to an "enable" expression
         3. A signal is inactive with respect to a "disable" expression
         4. A signal is not inactive with respect to a "disable" expression

In the case of P, if we are looking to activate B without explicitly
having configured A it's enough to consider A inactive if all of A's
"enable" signal expressions evaluate to "not active". If any evaluate to
"active" then the corresponding "disable" states must be applied so it
becomes inactive.

For example, on the AST2400 the pins composing GPIO bank H provide
signals ROMD8 through ROMD15 (high priority) and those for UART6 (low
priority). The mux states for ROMD8 through ROMD15 are aliased, i.e.
there are two mux states that result in the respective signals being
configured:

         A. SCU90[6]=1
         B. Strap[4,1:0]=100

Further, the second mux state is a 3-bit bitfield that explicitly
defines the enabled state but the disabled state is implicit, i.e. if
Strap[4,1:0] is not exactly "100" then ROMD8 through ROMD15 are not
considered active. This requires the mux function evaluation logic to
use approach 2. above, however the existing code was using approach 3.
The problem was brought to light on the Palmetto machines where the
strap register value is 0x120ce416, and prevented GPIO requests in bank
H from succeeding despite the hardware being in a position to allow
them.

Fixes: 318398c09a8d ("pinctrl: Add core pinctrl support for Aspeed SoCs")
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-18 14:36:10 +02:00
Arnd Bergmann
5595603526 pinctrl: aspeed: fix regmap error handling
The newly added aspeed driver tries to check for a negative return
value from a pinctrl function, but stores the intermediate value in
a 'bool' variable, which cannot work:

drivers/pinctrl/aspeed/pinctrl-aspeed.c: In function 'aspeed_sig_expr_set':
drivers/pinctrl/aspeed/pinctrl-aspeed.c:192:11: error: comparison of constant '0' with boolean expression is always false [-Werror=bool-compare]

This slightly reworks the logic to use an explicit comparison with zero
before assigning to the temporary variable.

Reported-by: Colin King <colin.king@canonical.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-13 10:41:49 +02:00
Andrew Jeffery
56e57cb6c0 pinctrl: Add pinctrl-aspeed-g5 driver
A small subset of pins and functions are exposed. The selection of pins
and functions is driven by the development of OpenBMC[1] on the
AST2500 SoC, particularly around booting the IBM Witherspoon platform.

[1] https://github.com/openbmc/docs

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-07 16:53:37 +02:00
Andrew Jeffery
524594d401 pinctrl: Add pinctrl-aspeed-g4 driver
A subset of the pins and functions are exposed. The selection of
functions and pins is driven by the development of OpenBMC[1] on the
AST2400 SoC, particularly around booting the OpenPOWER Palmetto
development machine.

[1] https://github.com/openbmc/docs

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-07 16:51:49 +02:00
Andrew Jeffery
4d3d0e4272 pinctrl: Add core support for Aspeed SoCs
The Aspeed SoCs typically provide more than 200 pins for GPIO and other
functions. The signal enabled on a pin is determined on a priority
basis, where a given pin can provide a number of different signal types.

In addition to the priority levels, the Aspeed pin controllers describe
the signal active on a pin by compound logical expressions involving
multiple operators, registers and bits. Some difficulty arises as a
pin's function bit masks for each priority level are frequently not the
same (i.e. we cannot just flip a bit to change from a high to low
priority signal), or even in the same register(s). Some configuration
bits affect multiple pins, while in other cases the signals for a bus
must each be enabled individually.

Together, these features give rise to some complexity in the
implementation. A more complete description of the complexities is
provided in the associated header file.

The patch doesn't implement pinctrl/pinmux/pinconf for any particular
Aspeed SoC, rather it adds the framework for defining pinmux
configurations.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-07 16:48:22 +02:00