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2018-08-31pinctrl: remove unnecessary unlikely()Igor Stoppa1-1/+1
WARN_ON() already contains an unlikely(), so it's not necessary to wrap it into another. Signed-off-by: Igor Stoppa <igor.stoppa@huawei.com> Cc: Andrew Jeffery <andrew@aj.id.au> Cc: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-28pinctrl: aspeed: Fix documentationJoel Stanley1-2/+2
Fixes these warnings: pinctrl-aspeed.c:112: warning: Function parameter or member 'map' not described in 'aspeed_sig_desc_eval' pinctrl-aspeed.c:112: warning: Excess function parameter 'regmap' description in 'aspeed_sig_desc_eval' Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-08-31pinctrl: aspeed: Rework strap register write logic for the AST2500Andrew Jeffery1-10/+16
Yong Li found that writes to the AST2500 strapping register were not properly supported by the Aspeed pinctrl core and provided a patch to rectify the problem. Several revisions of the patch were posted and ultimately v4 should have been applied, however some unfortunate liberal application of tags on my part lead to confusion between v3[1] and v4[2]. Generate the diff between v3 and v4 to apply as a fixup patch. [1] http://patchwork.ozlabs.org/patch/801662/ [2] http://patchwork.ozlabs.org/patch/802946/ Cc: Yong Li <sdliyong@gmail.com> Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-08-22pinctrl: aspeed: Fix ast2500 strap register write logicYong Li1-2/+17
On AST2500, the hardware strap register(SCU70) only accepts write ‘1’, to clear it to ‘0’, must set bits(write ‘1’) to SCU7C Signed-off-by: Yong Li <sdliyong@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Tested-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-04-24pinctrl: aspeed: Add core pinconf supportAndrew Jeffery1-0/+211
Several pinconf parameters have a fairly straight-forward mapping onto the Aspeed pin controller. These include management of pull-down bias, drive-strength, and some debounce configuration. Pin biasing largely is managed on a per-GPIO-bank basis, aside from the ADC and RMII/RGMII pins. As the bias configuration for each pin in a bank maps onto a single per-bank bit, configuration tables will be introduced to describe the ranges of pins and the supported pinconf parameter. The use of tables also helps with the sparse support of pinconf properties, and the fact that not all GPIO banks support biasing or drive-strength configuration. Further, as the pin controller uses a consistent approach for bias and drive strength configuration at the register level, a second table is defined for looking up the the bit-state required to enable or query the provided configuration. Testing for pinctrl-aspeed-g4 was performed on an OpenPOWER Palmetto system, and pinctrl-aspeed-g5 on an AST2500EVB as well as under QEMU. The test method was to set the appropriate bits via devmem and verify the result through the controller's pinconf-pins debugfs file. This simultaneously validates the get() path and half of the set() path. The remainder of the set() path was validated by configuring a handful of pins via the devicetree with the supported pinconf properties and verifying the appropriate registers were touched. Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-03-14pinctrl: aspeed: Allow disabling Port D and Port E loopback modeRick Altherr1-2/+12
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>
2016-12-28pinctrl: aspeed: Fix kerneldoc return descriptionsAndrew Jeffery1-6/+6
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>
2016-12-27pinctrl: aspeed: Read and write bits in LPC and GFX controllersAndrew Jeffery1-61/+100
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>
2016-10-18pinctrl: aspeed: "Not enabled" is a significant mux stateAndrew Jeffery1-5/+7
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>
2016-09-13pinctrl: aspeed: fix regmap error handlingArnd Bergmann1-3/+3
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>
2016-09-07pinctrl: Add core support for Aspeed SoCsAndrew Jeffery1-0/+498
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>