diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2018-05-08 03:06:38 +0200 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2018-06-12 06:04:41 +0200 |
| commit | bc1099d2b2519fa0f6c7613d8de398df8438a36b (patch) | |
| tree | 98cb568b10bff23b977ea82be4b8b804f34f5412 /arch/arm/boot | |
| parent | fsi/fsi-master-gpio: Sample input data on different clock phase (diff) | |
| download | linux-bc1099d2b2519fa0f6c7613d8de398df8438a36b.tar.xz linux-bc1099d2b2519fa0f6c7613d8de398df8438a36b.zip | |
fsi/fsi-master-gpio: Add "no-gpio-delays" option
This adds support for an optional device-tree property that
makes the driver skip all the delays around clocking the
GPIOs and set it in the device-tree of common POWER9 based
OpenPower platforms.
This useful on chips like the AST2500 where the GPIO block is
running at a fairly low clock frequency (25Mhz typically). In
this case, the delays are unnecessary and due to the low
precision of the timers, actually quite harmful in terms of
performance.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Diffstat (limited to 'arch/arm/boot')
| -rw-r--r-- | arch/arm/boot/dts/aspeed-bmc-opp-romulus.dts | 1 | ||||
| -rw-r--r-- | arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts | 1 | ||||
| -rw-r--r-- | arch/arm/boot/dts/aspeed-bmc-opp-zaius.dts | 1 |
3 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/boot/dts/aspeed-bmc-opp-romulus.dts b/arch/arm/boot/dts/aspeed-bmc-opp-romulus.dts index 389f5f83bef9..0b9b37d4d6ef 100644 --- a/arch/arm/boot/dts/aspeed-bmc-opp-romulus.dts +++ b/arch/arm/boot/dts/aspeed-bmc-opp-romulus.dts @@ -52,6 +52,7 @@ compatible = "fsi-master-gpio", "fsi-master"; #address-cells = <2>; #size-cells = <0>; + no-gpio-delays; clock-gpios = <&gpio ASPEED_GPIO(AA, 0) GPIO_ACTIVE_HIGH>; data-gpios = <&gpio ASPEED_GPIO(AA, 2) GPIO_ACTIVE_HIGH>; diff --git a/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts b/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts index 78a511e6e482..656036106001 100644 --- a/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts +++ b/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts @@ -153,6 +153,7 @@ compatible = "fsi-master-gpio", "fsi-master"; #address-cells = <2>; #size-cells = <0>; + no-gpio-delays; clock-gpios = <&gpio ASPEED_GPIO(AA, 0) GPIO_ACTIVE_HIGH>; data-gpios = <&gpio ASPEED_GPIO(E, 0) GPIO_ACTIVE_HIGH>; diff --git a/arch/arm/boot/dts/aspeed-bmc-opp-zaius.dts b/arch/arm/boot/dts/aspeed-bmc-opp-zaius.dts index ccbf645ab84d..2c5aa90a546d 100644 --- a/arch/arm/boot/dts/aspeed-bmc-opp-zaius.dts +++ b/arch/arm/boot/dts/aspeed-bmc-opp-zaius.dts @@ -91,6 +91,7 @@ compatible = "fsi-master-gpio", "fsi-master"; #address-cells = <2>; #size-cells = <0>; + no-gpio-delays; trans-gpios = <&gpio ASPEED_GPIO(O, 6) GPIO_ACTIVE_HIGH>; enable-gpios = <&gpio ASPEED_GPIO(D, 0) GPIO_ACTIVE_HIGH>; |