| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | Altera Passive Serial SPI FPGA Manager |
| 2 | |
| 3 | Altera FPGAs support a method of loading the bitstream over what is |
| 4 | referred to as "passive serial". |
| 5 | The passive serial link is not technically SPI, and might require extra |
| 6 | circuits in order to play nicely with other SPI slaves on the same bus. |
| 7 | |
| 8 | See https://www.altera.com/literature/hb/cyc/cyc_c51013.pdf |
| 9 | |
| 10 | Required properties: |
| 11 | - compatible: Must be one of the following: |
| 12 | "altr,fpga-passive-serial", |
| 13 | "altr,fpga-arria10-passive-serial" |
| 14 | - reg: SPI chip select of the FPGA |
| 15 | - nconfig-gpios: config pin (referred to as nCONFIG in the manual) |
| 16 | - nstat-gpios: status pin (referred to as nSTATUS in the manual) |
| 17 | |
| 18 | Optional properties: |
| 19 | - confd-gpios: confd pin (referred to as CONF_DONE in the manual) |
| 20 | |
| 21 | Example: |
| 22 | fpga: fpga@0 { |
| 23 | compatible = "altr,fpga-passive-serial"; |
| 24 | spi-max-frequency = <20000000>; |
| 25 | reg = <0>; |
| 26 | nconfig-gpios = <&gpio4 9 GPIO_ACTIVE_LOW>; |
| 27 | nstat-gpios = <&gpio4 11 GPIO_ACTIVE_LOW>; |
| 28 | confd-gpios = <&gpio4 12 GPIO_ACTIVE_LOW>; |
| 29 | }; |