Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | STMicroelectronics STM32H7 Reset and Clock Controller |
| 2 | ===================================================== |
| 3 | |
| 4 | The RCC IP is both a reset and a clock controller. |
| 5 | |
| 6 | Please refer to clock-bindings.txt for common clock controller binding usage. |
| 7 | Please also refer to reset.txt for common reset controller binding usage. |
| 8 | |
| 9 | Required properties: |
| 10 | - compatible: Should be: |
| 11 | "st,stm32h743-rcc" |
| 12 | |
| 13 | - reg: should be register base and length as documented in the |
| 14 | datasheet |
| 15 | |
| 16 | - #reset-cells: 1, see below |
| 17 | |
| 18 | - #clock-cells : from common clock binding; shall be set to 1 |
| 19 | |
| 20 | - clocks: External oscillator clock phandle |
| 21 | - high speed external clock signal (HSE) |
| 22 | - low speed external clock signal (LSE) |
| 23 | - external I2S clock (I2S_CKIN) |
| 24 | |
| 25 | Optional properties: |
| 26 | - st,syscfg: phandle for pwrcfg, mandatory to disable/enable backup domain |
| 27 | write protection (RTC clock). |
| 28 | |
| 29 | Example: |
| 30 | |
| 31 | rcc: reset-clock-controller@58024400 { |
| 32 | compatible = "st,stm32h743-rcc", "st,stm32-rcc"; |
| 33 | reg = <0x58024400 0x400>; |
| 34 | #reset-cells = <1>; |
| 35 | #clock-cells = <1>; |
| 36 | clocks = <&clk_hse>, <&clk_lse>, <&clk_i2s_ckin>; |
| 37 | |
| 38 | st,syscfg = <&pwrcfg>; |
| 39 | }; |
| 40 | |
| 41 | The peripheral clock consumer should specify the desired clock by |
| 42 | having the clock ID in its "clocks" phandle cell. |
| 43 | |
| 44 | Example: |
| 45 | |
| 46 | timer5: timer@40000c00 { |
| 47 | compatible = "st,stm32-timer"; |
| 48 | reg = <0x40000c00 0x400>; |
| 49 | interrupts = <50>; |
| 50 | clocks = <&rcc TIM5_CK>; |
| 51 | }; |
| 52 | |
| 53 | Specifying softreset control of devices |
| 54 | ======================================= |
| 55 | |
| 56 | Device nodes should specify the reset channel required in their "resets" |
| 57 | property, containing a phandle to the reset device node and an index specifying |
| 58 | which channel to use. |
| 59 | The index is the bit number within the RCC registers bank, starting from RCC |
| 60 | base address. |
| 61 | It is calculated as: index = register_offset / 4 * 32 + bit_offset. |
| 62 | Where bit_offset is the bit offset within the register. |
| 63 | |
| 64 | For example, for CRC reset: |
| 65 | crc = AHB4RSTR_offset / 4 * 32 + CRCRST_bit_offset = 0x88 / 4 * 32 + 19 = 1107 |
| 66 | |
| 67 | Example: |
| 68 | |
| 69 | timer2 { |
| 70 | resets = <&rcc STM32H7_APB1L_RESET(TIM2)>; |
| 71 | }; |