| 109 | |
| 110 | ==== GW7100 Serial Port Pin Muxing |
| 111 | Some SPI lines can be converted to UART on the GW7100 on the J4 header. |
| 112 | |
| 113 | J4 pins 7 and 9. |
| 114 | |
| 115 | Note of course you have to give up some hardware features that reply on the SPI bus: |
| 116 | - Make sure U13 TPM is unloaded |
| 117 | |
| 118 | To make spi2 uart4 (2-wire UART, no flow control) you could do the following device tree fragment at the bottom of the device-tree (ie can modify imx8mm-venice-gw71xx-0x.dts): |
| 119 | {{{ |
| 120 | &ecspi2 { |
| 121 | status = "disabled"; |
| 122 | }; |
| 123 | |
| 124 | &uart4 { |
| 125 | pinctrl-names = "default"; |
| 126 | pinctrl-0 = <&pinctrl_uart4>; |
| 127 | status = "okay"; |
| 128 | }; |
| 129 | |
| 130 | &iomuxc { |
| 131 | pinctrl_uart4: uart4grp { |
| 132 | fsl,pins = < |
| 133 | MX8MM_IOMUXC_ECSPI2_MOSI_UART4_DCE_TX 0x140 |
| 134 | MX8MM_IOMUXC_ECSPI2_SCLK_UART4_DCE_RX 0x140 |
| 135 | >; |
| 136 | }; |
| 137 | }}} |
| 138 | |
| 139 | |
| 140 | More is discussed here: |
| 141 | [wiki:venice/DigitalIO] |