| 91 | | Notes: |
| 92 | | 1. While only a single Chip Select (CS) is brought out to an external connector and of the DIO pins routed to ARM GPIO's can be used as additional chip-selects (contact support@gateworks.com for details) |
| 93 | | 2. Note that the Cavium ThunderX SPI controller in the CN80XX on the Newport Product family only supports half-duplex SPI transfers. Drivers that use full-duplex transactions can be modified to support half-duplex (see [https://github.com/Gateworks/linux-newport/commit/cb270339619ccf2b50dfd3604a03626f85830453 'can:mcp251x: convert driver to half-duplex SPI'] as en example. |
| 94 | | 3. Note that the Cavium ThunderX SPI controller in the CN80XX only supports SPI mode 1 (which clock polarity (CPOL/CKP) is low, clock phase (CPHA) is high, and Clock edge (CKE/NCPHA) is low. |
| 95 | | |
| 96 | | |
| 97 | | You need to add a device-tree node to the SPI controller to use a kernel driver. Note that you can also access SPI from userspace using {{{spidev}}} (see [#spidev below]) |
| 98 | | |
| 99 | | An example device-tree child node for a Spansion m25p128 compatible device (S25FL128) 128Mbit (16MB) SPI NOR FLASH device would be: |
| 100 | | {{{#!c |
| 101 | | &spi_7_0 { |
| 102 | | flash: m25p80@0 { |
| 103 | | compatible = "spansion,m25p128", "jedec,spi-nor"; |
| 104 | | spi-max-frequency = <30000000>; |
| 105 | | reg = <0>; |
| 106 | | #address-cells = <1>; |
| 107 | | #size-cells = <1>; |
| 108 | | m25p,fast-read; |
| 109 | | |
| 110 | | partition@0 { |
| 111 | | label = "data"; |
| 112 | | reg = <0x0 0x1000000>; |
| 113 | | }; |
| 114 | | }; |
| 115 | | }; |
| 116 | | }}} |
| 117 | | - Note that this node must appear within the SPI host controller node (&spi_7_0) along with any other devices on the SPI bus. |
| 118 | | - Note that the values shown in the above node are specific to the m25p128, and can vary greatly from the actual device you are using. Replace attribute values as necessary. |
| 119 | | - When searching for your device ID string or its controlling driver, searching via a Linux LXR site like the one at [https://lxr.missinglinkelectronics.com/linux missing link electronics] for your device name can be helpful. |
| 120 | | |
| 121 | | |
| 122 | | === Ventana |
| 123 | | Gateworks Ventana boards support 3.3V TTL SPI to an off-board expansion connector with the following pinout: |
| 124 | | * 1 - MOSI |
| 125 | | * 2 - MISO |
| 126 | | * 3 - SCLK |
| 127 | | * 4 - SS0# (This is chip select 0) |
| 128 | | * 5 - 3.3V |
| 129 | | * GND |
| 130 | | |
| 131 | | Notes: |
| 132 | | 1. While only a single Chip Select (CS) is brought out to an external connector and of the DIO pins routed to ARM GPIO's can be used as additional chip-selects. For Ventana this is done via device-tree pinctrl. |
| 133 | | |
| 134 | | You need to add add a device-tree node to the SPI controller to use a kernel driver. Note that you can also access SPI from userspace using {{{spidev}}} (see [#spidev below]) |
| 135 | | |
| 136 | | An example device-tree child node for a Spansion m25p128 compatible device (S25FL128) 128Mbit (16MB) SPI NOR FLASH device would be: |
| 137 | | {{{#!c |
| 138 | | &ecspi2 { |
| 139 | | flash: m25p80@0 { |
| 140 | | compatible = "spansion,m25p128", "jedec,spi-nor"; |
| 141 | | spi-max-frequency = <30000000>; |
| 142 | | reg = <0>; |
| 143 | | #address-cells = <1>; |
| 144 | | #size-cells = <1>; |
| 145 | | m25p,fast-read; |
| 146 | | |
| 147 | | partition@0 { |
| 148 | | label = "data"; |
| 149 | | reg = <0x0 0x1000000>; |
| 150 | | }; |
| 151 | | }; |
| 152 | | }; |
| 153 | | }}} |
| 154 | | - Note that this node must appear within the SPI host controller. For a list of device-tree nodes [#spitable see above]. |
| 155 | | - Note that the values shown in the above node are specific to the m25p128, and can vary greatly from the actual device you are using. Replace attribute values as necessary. |
| 156 | | - When searching for your device ID string or its controlling driver, searching via a Linux LXR site like the one at [https://lxr.missinglinkelectronics.com/linux missing link electronics] for your device name can be helpful. |
| 216 | | /* |
| 217 | | * SPI_CS1 goes to the Microchip MCP2515 CAN controller (GW6204/GW6304/GW6404) |
| 218 | | */ |
| 219 | | can0: can@1 { |
| 220 | | compatible = "microchip,mcp2515","linux,spidev"; |
| 221 | | reg = <1>; |
| 222 | | clocks = <&can20m>; |
| 223 | | oscillator-frequency = <20000000>; |
| 224 | | interrupt-parent = <&gpio_6_0>; |
| 225 | | interrupts = <5 0x8>; /* IRQ_TYPE_LEVEL_LOW */ |
| 226 | | spi-max-frequency = <10000000>; |
| 227 | | }; |
| 228 | | }; |
| 229 | | }}} |
| 230 | | - GW610x which has a single SPI controller with 2 chip selects, with CS0 going to an off-board connector. Change dts/gw610x-linux.dtsi to add the following at the end: |
| 231 | | {{{#!c |
| 232 | | &spi_7_0 { |
| 233 | | /* |
| 234 | | * SPI_CS0 goes to the off-board connector |
| 235 | | * compatible must match a string from drivers/spi/spidev.c's compatible list |
| 236 | | */ |
| 237 | | spidev0: spidev0@0 { |
| 238 | | compatible = "rohm,dh2228fv"; |
| 239 | | reg = <0>; |
| 240 | | spi-max-frequency = <10000000>; |
| 241 | | }; |
| 242 | | }; |
| 243 | | }}} |
| 244 | | * Ventana: |
| 245 | | - GW54xx (arch/arm/boot/dts/imx6qdl-gw52xx.dtsi) which brings out the ecspi2 host interface to an off-board connector with GPIO2_IO26 as a chip select: |
| 246 | | {{{#!c |
| 247 | | &ecspi2 { |
| 248 | | cs-gpios = <&gpio2 26 GPIO_ACTIVE_HIGH>; |
| 249 | | pinctrl-names = "default"; |
| 250 | | pinctrl-0 = <&pinctrl_ecspi2>; |
| 251 | | status = "okay"; |
| 252 | | |
| 253 | | spidev0: spidev@0 { |
| 254 | | compatible = "rohm,dh2228fv"; |
| 255 | | reg = <0>; |
| 256 | | spi-max-frequency = <60000000>; |
| 257 | | }; |
| 258 | | }; |
| 259 | | }}} |
| 260 | | - GW52xx (arch/arm/boot/dts/imx6qdl-gw53xx.dtsi) which brings out the ecspi3 host interface to an off-board connector with GPIO4_IO24 as a chip select: |
| 261 | | {{{#!c |
| 262 | | &ecspi3 { |
| 263 | | cs-gpios = <&gpio4 24 GPIO_ACTIVE_HIGH>; |
| 264 | | pinctrl-names = "default"; |
| 265 | | pinctrl-0 = <&pinctrl_ecspi3>; |
| 266 | | status = "okay"; |
| 267 | | |
| 268 | | spidev0: spidev@0 { |
| 269 | | compatible = "rohm,dh2228fv"; |
| 270 | | reg = <0>; |
| 271 | | spi-max-frequency = <60000000>; |
| 272 | | }; |
| 273 | | }; |
| 274 | | }}} |
