diff options
Diffstat (limited to 'dts/Bindings/spi')
| -rw-r--r-- | dts/Bindings/spi/snps,dw-apb-ssi.yaml | 2 | ||||
| -rw-r--r-- | dts/Bindings/spi/spi-controller.yaml | 27 | ||||
| -rw-r--r-- | dts/Bindings/spi/spi-sifive.yaml | 10 |
3 files changed, 35 insertions, 4 deletions
diff --git a/dts/Bindings/spi/snps,dw-apb-ssi.yaml b/dts/Bindings/spi/snps,dw-apb-ssi.yaml index 99ed9b416e..4825157cd9 100644 --- a/dts/Bindings/spi/snps,dw-apb-ssi.yaml +++ b/dts/Bindings/spi/snps,dw-apb-ssi.yaml @@ -65,6 +65,8 @@ properties: const: baikal,bt1-ssi - description: Baikal-T1 System Boot SPI Controller const: baikal,bt1-sys-ssi + - description: Canaan Kendryte K210 SoS SPI Controller + const: canaan,k210-spi reg: minItems: 1 diff --git a/dts/Bindings/spi/spi-controller.yaml b/dts/Bindings/spi/spi-controller.yaml index 1b56d5e40f..5f50581010 100644 --- a/dts/Bindings/spi/spi-controller.yaml +++ b/dts/Bindings/spi/spi-controller.yaml @@ -42,6 +42,33 @@ properties: cs2 : &gpio1 1 0 cs3 : &gpio1 2 0 + The second flag of a gpio descriptor can be GPIO_ACTIVE_HIGH (0) + or GPIO_ACTIVE_LOW(1). Legacy device trees often use 0. + + There is a special rule set for combining the second flag of an + cs-gpio with the optional spi-cs-high flag for SPI slaves. + + Each table entry defines how the CS pin is to be physically + driven (not considering potential gpio inversions by pinmux): + + device node | cs-gpio | CS pin state active | Note + ================+===============+=====================+===== + spi-cs-high | - | H | + - | - | L | + spi-cs-high | ACTIVE_HIGH | H | + - | ACTIVE_HIGH | L | 1 + spi-cs-high | ACTIVE_LOW | H | 2 + - | ACTIVE_LOW | L | + + Notes: + 1) Should print a warning about polarity inversion. + Here it would be wise to avoid and define the gpio as + ACTIVE_LOW. + 2) Should print a warning about polarity inversion + because ACTIVE_LOW is overridden by spi-cs-high. + Should be generally avoided and be replaced by + spi-cs-high + ACTIVE_HIGH. + num-cs: $ref: /schemas/types.yaml#/definitions/uint32 description: diff --git a/dts/Bindings/spi/spi-sifive.yaml b/dts/Bindings/spi/spi-sifive.yaml index 56dcf1d35d..6e7e394fc1 100644 --- a/dts/Bindings/spi/spi-sifive.yaml +++ b/dts/Bindings/spi/spi-sifive.yaml @@ -17,15 +17,17 @@ allOf: properties: compatible: items: - - const: sifive,fu540-c000-spi + - enum: + - sifive,fu540-c000-spi + - sifive,fu740-c000-spi - const: sifive,spi0 description: Should be "sifive,<chip>-spi" and "sifive,spi<version>". Supported compatible strings are - - "sifive,fu540-c000-spi" for the SiFive SPI v0 as integrated - onto the SiFive FU540 chip, and "sifive,spi0" for the SiFive - SPI v0 IP block with no chip integration tweaks. + "sifive,fu540-c000-spi" and "sifive,fu740-c000-spi" for the SiFive SPI v0 + as integrated onto the SiFive FU540 and FU740 chip resp, and "sifive,spi0" + for the SiFive SPI v0 IP block with no chip integration tweaks. Please refer to sifive-blocks-ip-versioning.txt for details SPI RTL that corresponds to the IP block version numbers can be found here - |