This adds documentation of device tree bindings for the STM32 reset controller. Tested-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx> --- .../devicetree/bindings/reset/st,stm32-rcc.txt | 107 +++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 Documentation/devicetree/bindings/reset/st,stm32-rcc.txt diff --git a/Documentation/devicetree/bindings/reset/st,stm32-rcc.txt b/Documentation/devicetree/bindings/reset/st,stm32-rcc.txt new file mode 100644 index 0000000..e2e2f25 --- /dev/null +++ b/Documentation/devicetree/bindings/reset/st,stm32-rcc.txt @@ -0,0 +1,107 @@ +STMicroelectronics STM32 Peripheral Reset Controller +==================================================== + +The RCC IP is both a reset and a clock controller. This documentation only +document the reset part. + +Please also refer to reset.txt in this directory for common reset +controller binding usage. + +Required properties: +- compatible: Should be "st,stm32-rcc" +- reg: should be register base and length as documented in the + datasheet +- #reset-cells: 1, see below + +example: + +rcc: reset@40023800 { + #reset-cells = <1>; + compatible = "st,stm32-rcc"; + reg = <0x40023800 0x400>; +}; + +Specifying softreset control of devices +======================================= + +Device nodes should specify the reset channel required in their "resets" +property, containing a phandle to the reset device node and an index specifying +which channel to use. +The index is the bit number within the RCC registers bank, starting from RCC +base address. +It is calculated as: index = register_offset / 4 * 32 + bit_offset. +Where bit_offset is the bit offset within the register. +For example, for CRC reset: + crc = AHB1RSTR_offset / 4 * 32 + CRCRST_bit_offset = 0x10 / 4 * 32 + 12 = 140 + +example: + + timer2 { + resets = <&rcc 256>; + }; + +List of valid indices for STM32F429: + - gpioa: 128 + - gpiob: 129 + - gpioc: 130 + - gpiod: 131 + - gpioe: 132 + - gpiof: 133 + - gpiog: 134 + - gpioh: 135 + - gpioi: 136 + - gpioj: 137 + - gpiok: 138 + - crc: 140 + - dma1: 149 + - dma2: 150 + - dma2d: 151 + - ethmac: 153 + - otghs: 157 + - dcmi: 160 + - cryp: 164 + - hash: 165 + - rng: 166 + - otgfs: 167 + - fmc: 192 + - tim2: 256 + - tim3: 257 + - tim4: 258 + - tim5: 259 + - tim6: 260 + - tim7: 261 + - tim12: 262 + - tim13: 263 + - tim14: 264 + - wwdg: 267 + - spi2: 270 + - spi3: 271 + - uart2: 273 + - uart3: 274 + - uart4: 275 + - uart5: 276 + - i2c1: 277 + - i2c2: 278 + - i2c3: 279 + - can1: 281 + - can2: 282 + - pwr: 284 + - dac: 285 + - uart7: 286 + - uart8: 287 + - tim1: 288 + - tim8: 289 + - usart1: 292 + - usart6: 293 + - adc: 296 + - sdio: 299 + - spi1: 300 + - spi4: 301 + - syscfg: 302 + - tim9: 304 + - tim10: 305 + - tim11: 306 + - spi5: 308 + - spi6: 309 + - sai1: 310 + - ltdc: 314 -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html