diff options
Diffstat (limited to 'target/linux/gemini/patches-4.14/0004-pinctrl-Add-skew-delay-pin-config-and-bindings.patch')
| -rw-r--r-- | target/linux/gemini/patches-4.14/0004-pinctrl-Add-skew-delay-pin-config-and-bindings.patch | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/target/linux/gemini/patches-4.14/0004-pinctrl-Add-skew-delay-pin-config-and-bindings.patch b/target/linux/gemini/patches-4.14/0004-pinctrl-Add-skew-delay-pin-config-and-bindings.patch new file mode 100644 index 0000000000..ac39a3282d --- /dev/null +++ b/target/linux/gemini/patches-4.14/0004-pinctrl-Add-skew-delay-pin-config-and-bindings.patch @@ -0,0 +1,73 @@ +From eb3742c4250c6a79e7080bdb6286e5df50c7f26a Mon Sep 17 00:00:00 2001 +From: Linus Walleij <linus.walleij@linaro.org> +Date: Sat, 28 Oct 2017 15:37:17 +0200 +Subject: [PATCH 04/31] pinctrl: Add skew-delay pin config and bindings + +Some pin controllers (such as the Gemini) can control the +expected clock skew and output delay on certain pins with a +sub-nanosecond granularity. This is typically done by shunting +in a number of double inverters in front of or behind the pin. +Make it possible to configure this with a generic binding. + +Cc: devicetree@vger.kernel.org +Acked-by: Rob Herring <robh@kernel.org> +Acked-by: Hans Ulli Kroll <ulli.kroll@googlemail.com> +Signed-off-by: Linus Walleij <linus.walleij@linaro.org> +--- + Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt | 4 ++++ + drivers/pinctrl/pinconf-generic.c | 2 ++ + include/linux/pinctrl/pinconf-generic.h | 5 +++++ + 3 files changed, 11 insertions(+) + +--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt ++++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt +@@ -271,6 +271,10 @@ output-high - set the pin to output mod + sleep-hardware-state - indicate this is sleep related state which will be programmed + into the registers for the sleep state. + slew-rate - set the slew rate ++skew-delay - this affects the expected clock skew on input pins ++ and the delay before latching a value to an output ++ pin. Typically indicates how many double-inverters are ++ used to delay the signal. + + For example: + +--- a/drivers/pinctrl/pinconf-generic.c ++++ b/drivers/pinctrl/pinconf-generic.c +@@ -49,6 +49,7 @@ static const struct pin_config_item conf + PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true), + PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false), + PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true), ++ PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true), + }; + + static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev, +@@ -181,6 +182,7 @@ static const struct pinconf_generic_para + { "power-source", PIN_CONFIG_POWER_SOURCE, 0 }, + { "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 }, + { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 }, ++ { "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 }, + }; + + /** +--- a/include/linux/pinctrl/pinconf-generic.h ++++ b/include/linux/pinctrl/pinconf-generic.h +@@ -90,6 +90,10 @@ + * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to + * this parameter (on a custom format) tells the driver which alternative + * slew rate to use. ++ * @PIN_CONFIG_SKEW_DELAY: if the pin has programmable skew rate (on inputs) ++ * or latch delay (on outputs) this parameter (in a custom format) ++ * specifies the clock skew or latch delay. It typically controls how ++ * many double inverters are put in front of the line. + * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if + * you need to pass in custom configurations to the pin controller, use + * PIN_CONFIG_END+1 as the base offset. +@@ -117,6 +121,7 @@ enum pin_config_param { + PIN_CONFIG_POWER_SOURCE, + PIN_CONFIG_SLEEP_HARDWARE_STATE, + PIN_CONFIG_SLEW_RATE, ++ PIN_CONFIG_SKEW_DELAY, + PIN_CONFIG_END = 0x7F, + PIN_CONFIG_MAX = 0xFF, + }; |