| Rockchip SRAM for IO Voltage Domains: |
| ------------------------------------- |
| |
| IO domain voltages on some Rockchip SoCs are variable but need to be |
| kept in sync between the regulators and the SoC using a special |
| register. |
| |
| A specific example using rk3288: |
| - If the regulator hooked up to a pin like SDMMC0_VDD is 3.3V then |
| bit 7 of GRF_IO_VSEL needs to be 0. If the regulator hooked up to |
| that same pin is 1.8V then bit 7 of GRF_IO_VSEL needs to be 1. |
| |
| Said another way, this driver simply handles keeping bits in the SoC's |
| general register file (GRF) in sync with the actual value of a voltage |
| hooked up to the pins. |
| |
| Note that this driver specifically doesn't include: |
| - any logic for deciding what voltage we should set regulators to |
| - any logic for deciding whether regulators (or internal SoC blocks) |
| should have power or not have power |
| |
| If there were some other software that had the smarts of making |
| decisions about regulators, it would work in conjunction with this |
| driver. When that other software adjusted a regulator's voltage then |
| this driver would handle telling the SoC about it. A good example is |
| vqmmc for SD. In that case the dw_mmc driver simply is told about a |
| regulator. It changes the regulator between 3.3V and 1.8V at the |
| right time. This driver notices the change and makes sure that the |
| SoC is on the same page. |
| |
| |
| Required properties: |
| - compatible: should be one of: |
| - "rockchip,rk3188-io-voltage-domain" for rk3188 |
| - "rockchip,rk3228-io-voltage-domain" for rk3228 |
| - "rockchip,rk3288-io-voltage-domain" for rk3288 |
| - "rockchip,rk3328-io-voltage-domain" for rk3328 |
| - "rockchip,rk3368-io-voltage-domain" for rk3368 |
| - "rockchip,rk3368-pmu-io-voltage-domain" for rk3368 pmu-domains |
| - "rockchip,rk3399-io-voltage-domain" for rk3399 |
| - "rockchip,rk3399-pmu-io-voltage-domain" for rk3399 pmu-domains |
| - "rockchip,rv1108-io-voltage-domain" for rv1108 |
| - "rockchip,rv1108-pmu-io-voltage-domain" for rv1108 pmu-domains |
| |
| Deprecated properties: |
| - rockchip,grf: phandle to the syscon managing the "general register files" |
| Systems should move the io-domains to a sub-node of the grf simple-mfd. |
| |
| You specify supplies using the standard regulator bindings by including |
| a phandle the relevant regulator. All specified supplies must be able |
| to report their voltage. The IO Voltage Domain for any non-specified |
| supplies will be not be touched. |
| |
| Possible supplies for rk3188: |
| - ap0-supply: The supply connected to AP0_VCC. |
| - ap1-supply: The supply connected to AP1_VCC. |
| - cif-supply: The supply connected to CIF_VCC. |
| - flash-supply: The supply connected to FLASH_VCC. |
| - lcdc0-supply: The supply connected to LCD0_VCC. |
| - lcdc1-supply: The supply connected to LCD1_VCC. |
| - vccio0-supply: The supply connected to VCCIO0. |
| - vccio1-supply: The supply connected to VCCIO1. |
| Sometimes also labeled VCCIO1 and VCCIO2. |
| |
| Possible supplies for rk3228: |
| - vccio1-supply: The supply connected to VCCIO1. |
| - vccio2-supply: The supply connected to VCCIO2. |
| - vccio3-supply: The supply connected to VCCIO3. |
| - vccio4-supply: The supply connected to VCCIO4. |
| |
| Possible supplies for rk3288: |
| - audio-supply: The supply connected to APIO4_VDD. |
| - bb-supply: The supply connected to APIO5_VDD. |
| - dvp-supply: The supply connected to DVPIO_VDD. |
| - flash0-supply: The supply connected to FLASH0_VDD. Typically for eMMC |
| - flash1-supply: The supply connected to FLASH1_VDD. Also known as SDIO1. |
| - gpio30-supply: The supply connected to APIO1_VDD. |
| - gpio1830 The supply connected to APIO2_VDD. |
| - lcdc-supply: The supply connected to LCDC_VDD. |
| - sdcard-supply: The supply connected to SDMMC0_VDD. |
| - wifi-supply: The supply connected to APIO3_VDD. Also known as SDIO0. |
| |
| Possible supplies for rk3368: |
| - audio-supply: The supply connected to APIO3_VDD. |
| - dvp-supply: The supply connected to DVPIO_VDD. |
| - flash0-supply: The supply connected to FLASH0_VDD. Typically for eMMC |
| - gpio30-supply: The supply connected to APIO1_VDD. |
| - gpio1830 The supply connected to APIO4_VDD. |
| - sdcard-supply: The supply connected to SDMMC0_VDD. |
| - wifi-supply: The supply connected to APIO2_VDD. Also known as SDIO0. |
| |
| Possible supplies for rk3368 pmu-domains: |
| - pmu-supply: The supply connected to PMUIO_VDD. |
| - vop-supply: The supply connected to LCDC_VDD. |
| |
| Possible supplies for rk3399: |
| - bt656-supply: The supply connected to APIO2_VDD. |
| - audio-supply: The supply connected to APIO5_VDD. |
| - sdmmc-supply: The supply connected to SDMMC0_VDD. |
| - gpio1830 The supply connected to APIO4_VDD. |
| |
| Possible supplies for rk3399 pmu-domains: |
| - pmu1830-supply:The supply connected to PMUIO2_VDD. |
| |
| Example: |
| |
| io-domains { |
| compatible = "rockchip,rk3288-io-voltage-domain"; |
| rockchip,grf = <&grf>; |
| |
| audio-supply = <&vcc18_codec>; |
| bb-supply = <&vcc33_io>; |
| dvp-supply = <&vcc_18>; |
| flash0-supply = <&vcc18_flashio>; |
| gpio1830-supply = <&vcc33_io>; |
| gpio30-supply = <&vcc33_pmuio>; |
| lcdc-supply = <&vcc33_lcd>; |
| sdcard-supply = <&vccio_sd>; |
| wifi-supply = <&vcc18_wl>; |
| }; |
