1These properties are common to multiple MMC host controllers. Any host 2that requires the respective functionality should implement them using 3these definitions. 4 5Interpreted by the OF core: 6- reg: Registers location and length. 7- interrupts: Interrupts used by the MMC controller. 8 9Card detection: 10If no property below is supplied, host native card detect is used. 11Only one of the properties in this section should be supplied: 12 - broken-cd: There is no card detection available; polling must be used. 13 - cd-gpios: Specify GPIOs for card detection, see gpio binding 14 - non-removable: non-removable slot (like eMMC); assume always present. 15 16Optional properties: 17- bus-width: Number of data lines, can be <1>, <4>, or <8>. The default 18 will be <1> if the property is absent. 19- wp-gpios: Specify GPIOs for write protection, see gpio binding 20- cd-inverted: when present, polarity on the CD line is inverted. See the note 21 below for the case, when a GPIO is used for the CD line 22- wp-inverted: when present, polarity on the WP line is inverted. See the note 23 below for the case, when a GPIO is used for the WP line 24- disable-wp: When set no physical WP line is present. This property should 25 only be specified when the controller has a dedicated write-protect 26 detection logic. If a GPIO is always used for the write-protect detection 27 logic it is sufficient to not specify wp-gpios property in the absence of a WP 28 line. 29- max-frequency: maximum operating clock frequency 30- no-1-8-v: when present, denotes that 1.8v card voltage is not supported on 31 this system, even if the controller claims it is. 32- cap-sd-highspeed: SD high-speed timing is supported 33- cap-mmc-highspeed: MMC high-speed timing is supported 34- sd-uhs-sdr12: SD UHS SDR12 speed is supported 35- sd-uhs-sdr25: SD UHS SDR25 speed is supported 36- sd-uhs-sdr50: SD UHS SDR50 speed is supported 37- sd-uhs-sdr104: SD UHS SDR104 speed is supported 38- sd-uhs-ddr50: SD UHS DDR50 speed is supported 39- cap-power-off-card: powering off the card is safe 40- cap-mmc-hw-reset: eMMC hardware reset is supported 41- cap-sdio-irq: enable SDIO IRQ signalling on this interface 42- full-pwr-cycle: full power cycle of the card is supported 43- mmc-ddr-3_3v: eMMC high-speed DDR mode(3.3V I/O) is supported 44- mmc-ddr-1_8v: eMMC high-speed DDR mode(1.8V I/O) is supported 45- mmc-ddr-1_2v: eMMC high-speed DDR mode(1.2V I/O) is supported 46- mmc-hs200-1_8v: eMMC HS200 mode(1.8V I/O) is supported 47- mmc-hs200-1_2v: eMMC HS200 mode(1.2V I/O) is supported 48- mmc-hs400-1_8v: eMMC HS400 mode(1.8V I/O) is supported 49- mmc-hs400-1_2v: eMMC HS400 mode(1.2V I/O) is supported 50- mmc-hs400-enhanced-strobe: eMMC HS400 enhanced strobe mode is supported 51- dsr: Value the card's (optional) Driver Stage Register (DSR) should be 52 programmed with. Valid range: [0 .. 0xffff]. 53- no-sdio: controller is limited to send sdio cmd during initialization 54- no-sd: controller is limited to send sd cmd during initialization 55- no-mmc: controller is limited to send mmc cmd during initialization 56 57*NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line 58polarity properties, we have to fix the meaning of the "normal" and "inverted" 59line levels. We choose to follow the SDHCI standard, which specifies both those 60lines as "active low." Therefore, using the "cd-inverted" property means, that 61the CD line is active high, i.e. it is high, when a card is inserted. Similar 62logic applies to the "wp-inverted" property. 63 64CD and WP lines can be implemented on the hardware in one of two ways: as GPIOs, 65specified in cd-gpios and wp-gpios properties, or as dedicated pins. Polarity of 66dedicated pins can be specified, using *-inverted properties. GPIO polarity can 67also be specified using the OF_GPIO_ACTIVE_LOW flag. This creates an ambiguity 68in the latter case. We choose to use the XOR logic for GPIO CD and WP lines. 69This means, the two properties are "superimposed," for example leaving the 70OF_GPIO_ACTIVE_LOW flag clear and specifying the respective *-inverted 71property results in a double-inversion and actually means the "normal" line 72polarity is in effect. 73 74Optional SDIO properties: 75- keep-power-in-suspend: Preserves card power during a suspend/resume cycle 76- wakeup-source: Enables wake up of host system on SDIO IRQ assertion 77 (Legacy property supported: "enable-sdio-wakeup") 78 79MMC power 80--------- 81 82Controllers may implement power control from both the connected cards and 83the IO signaling (for example to change to high-speed 1.8V signalling). If 84the system supports this, then the following two properties should point 85to valid regulator nodes: 86 87- vqmmc-supply: supply node for IO line power 88- vmmc-supply: supply node for card's power 89 90 91MMC power sequences: 92-------------------- 93 94System on chip designs may specify a specific MMC power sequence. To 95successfully detect an (e)MMC/SD/SDIO card, that power sequence must be 96maintained while initializing the card. 97 98Optional property: 99- mmc-pwrseq: phandle to the MMC power sequence node. See "mmc-pwrseq-*" 100 for documentation of MMC power sequence bindings. 101 102 103Use of Function subnodes 104------------------------ 105 106On embedded systems the cards connected to a host may need additional 107properties. These can be specified in subnodes to the host controller node. 108The subnodes are identified by the standard 'reg' property. 109Which information exactly can be specified depends on the bindings for the 110SDIO function driver for the subnode, as specified by the compatible string. 111 112Required host node properties when using function subnodes: 113- #address-cells: should be one. The cell is the slot id. 114- #size-cells: should be zero. 115 116Required function subnode properties: 117- reg: Must contain the SDIO function number of the function this subnode 118 describes. A value of 0 denotes the memory SD function, values from 119 1 to 7 denote the SDIO functions. 120 121Optional function subnode properties: 122- compatible: name of SDIO function following generic names recommended practice 123 124 125Examples 126-------- 127 128Basic example: 129 130sdhci@ab000000 { 131 compatible = "sdhci"; 132 reg = <0xab000000 0x200>; 133 interrupts = <23>; 134 bus-width = <4>; 135 cd-gpios = <&gpio 69 0>; 136 cd-inverted; 137 wp-gpios = <&gpio 70 0>; 138 max-frequency = <50000000>; 139 keep-power-in-suspend; 140 wakeup-source; 141 mmc-pwrseq = <&sdhci0_pwrseq> 142} 143 144Example with sdio function subnode: 145 146mmc3: mmc@01c12000 { 147 #address-cells = <1>; 148 #size-cells = <0>; 149 150 pinctrl-names = "default"; 151 pinctrl-0 = <&mmc3_pins_a>; 152 vmmc-supply = <®_vmmc3>; 153 bus-width = <4>; 154 non-removable; 155 mmc-pwrseq = <&sdhci0_pwrseq> 156 status = "okay"; 157 158 brcmf: bcrmf@1 { 159 reg = <1>; 160 compatible = "brcm,bcm43xx-fmac"; 161 interrupt-parent = <&pio>; 162 interrupts = <10 8>; /* PH10 / EINT10 */ 163 interrupt-names = "host-wake"; 164 }; 165}; 166