projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 662a9586 HS |
1 | Rockchip SRAM for IO Voltage Domains: |
| 2 | ------------------------------------- | |
| 3 | ||
| 4 | IO domain voltages on some Rockchip SoCs are variable but need to be | |
| 5 | kept in sync between the regulators and the SoC using a special | |
| 6 | register. | |
| 7 | ||
| 8 | A specific example using rk3288: | |
| 9 | - If the regulator hooked up to a pin like SDMMC0_VDD is 3.3V then | |
| 10 | bit 7 of GRF_IO_VSEL needs to be 0. If the regulator hooked up to | |
| 11 | that same pin is 1.8V then bit 7 of GRF_IO_VSEL needs to be 1. | |
| 12 | ||
| 13 | Said another way, this driver simply handles keeping bits in the SoC's | |
| 14 | general register file (GRF) in sync with the actual value of a voltage | |
| 15 | hooked up to the pins. | |
| 16 | ||
| 17 | Note that this driver specifically doesn't include: | |
| 18 | - any logic for deciding what voltage we should set regulators to | |
| 19 | - any logic for deciding whether regulators (or internal SoC blocks) | |
| 20 | should have power or not have power | |
| 21 | ||
| 22 | If there were some other software that had the smarts of making | |
| 23 | decisions about regulators, it would work in conjunction with this | |
| 24 | driver. When that other software adjusted a regulator's voltage then | |
| 25 | this driver would handle telling the SoC about it. A good example is | |
| 26 | vqmmc for SD. In that case the dw_mmc driver simply is told about a | |
| 27 | regulator. It changes the regulator between 3.3V and 1.8V at the | |
| 28 | right time. This driver notices the change and makes sure that the | |
| 29 | SoC is on the same page. | |
| 30 | ||
| 31 | ||
| 32 | Required properties: | |
| 33 | - compatible: should be one of: | |
| 34 | - "rockchip,rk3188-io-voltage-domain" for rk3188 | |
| 35 | - "rockchip,rk3288-io-voltage-domain" for rk3288 | |
| 3fc147e9 HS |
36 | - "rockchip,rk3368-io-voltage-domain" for rk3368 |
| 37 | - "rockchip,rk3368-pmu-io-voltage-domain" for rk3368 pmu-domains | |
| 662a9586 HS |
38 | - rockchip,grf: phandle to the syscon managing the "general register files" |
| 39 | ||
| 40 | ||
| 41 | You specify supplies using the standard regulator bindings by including | |
| ac3e8ea1 | 42 | a phandle the relevant regulator. All specified supplies must be able |
| 662a9586 HS |
43 | to report their voltage. The IO Voltage Domain for any non-specified |
| 44 | supplies will be not be touched. | |
| 45 | ||
| 46 | Possible supplies for rk3188: | |
| 47 | - ap0-supply: The supply connected to AP0_VCC. | |
| 48 | - ap1-supply: The supply connected to AP1_VCC. | |
| 49 | - cif-supply: The supply connected to CIF_VCC. | |
| 50 | - flash-supply: The supply connected to FLASH_VCC. | |
| 51 | - lcdc0-supply: The supply connected to LCD0_VCC. | |
| 52 | - lcdc1-supply: The supply connected to LCD1_VCC. | |
| 53 | - vccio0-supply: The supply connected to VCCIO0. | |
| 54 | - vccio1-supply: The supply connected to VCCIO1. | |
| 55 | Sometimes also labeled VCCIO1 and VCCIO2. | |
| 56 | ||
| 57 | Possible supplies for rk3288: | |
| 58 | - audio-supply: The supply connected to APIO4_VDD. | |
| 59 | - bb-supply: The supply connected to APIO5_VDD. | |
| 60 | - dvp-supply: The supply connected to DVPIO_VDD. | |
| 61 | - flash0-supply: The supply connected to FLASH0_VDD. Typically for eMMC | |
| 62 | - flash1-supply: The supply connected to FLASH1_VDD. Also known as SDIO1. | |
| 63 | - gpio30-supply: The supply connected to APIO1_VDD. | |
| 64 | - gpio1830 The supply connected to APIO2_VDD. | |
| 65 | - lcdc-supply: The supply connected to LCDC_VDD. | |
| 66 | - sdcard-supply: The supply connected to SDMMC0_VDD. | |
| 67 | - wifi-supply: The supply connected to APIO3_VDD. Also known as SDIO0. | |
| 68 | ||
| 3fc147e9 HS |
69 | Possible supplies for rk3368: |
| 70 | - audio-supply: The supply connected to APIO3_VDD. | |
| 71 | - dvp-supply: The supply connected to DVPIO_VDD. | |
| 72 | - flash0-supply: The supply connected to FLASH0_VDD. Typically for eMMC | |
| 73 | - gpio30-supply: The supply connected to APIO1_VDD. | |
| 74 | - gpio1830 The supply connected to APIO4_VDD. | |
| 75 | - sdcard-supply: The supply connected to SDMMC0_VDD. | |
| 76 | - wifi-supply: The supply connected to APIO2_VDD. Also known as SDIO0. | |
| 77 | ||
| 78 | Possible supplies for rk3368 pmu-domains: | |
| 79 | - pmu-supply: The supply connected to PMUIO_VDD. | |
| 80 | - vop-supply: The supply connected to LCDC_VDD. | |
| 662a9586 HS |
81 | |
| 82 | Example: | |
| 83 | ||
| 84 | io-domains { | |
| 85 | compatible = "rockchip,rk3288-io-voltage-domain"; | |
| 86 | rockchip,grf = <&grf>; | |
| 87 | ||
| 88 | audio-supply = <&vcc18_codec>; | |
| 89 | bb-supply = <&vcc33_io>; | |
| 90 | dvp-supply = <&vcc_18>; | |
| 91 | flash0-supply = <&vcc18_flashio>; | |
| 92 | gpio1830-supply = <&vcc33_io>; | |
| 93 | gpio30-supply = <&vcc33_pmuio>; | |
| 94 | lcdc-supply = <&vcc33_lcd>; | |
| 95 | sdcard-supply = <&vccio_sd>; | |
| 96 | wifi-supply = <&vcc18_wl>; | |
| 97 | }; |