1 These properties are common to multiple MMC host controllers. Any host
2 that requires the respective functionality should implement them using
5 Interpreted by the OF core:
6 - reg: Registers location and length.
7 - interrupts: Interrupts used by the MMC controller.
10 If no property below is supplied, host native card detect is used.
11 Only 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.
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 - cd-debounce-delay-ms: Set delay time before detecting card after card insert interrupt.
23 It's only valid when cd-gpios is present.
24 - wp-inverted: when present, polarity on the WP line is inverted. See the note
25 below for the case, when a GPIO is used for the WP line
26 - disable-wp: When set no physical WP line is present. This property should
27 only be specified when the controller has a dedicated write-protect
28 detection logic. If a GPIO is always used for the write-protect detection
29 logic it is sufficient to not specify wp-gpios property in the absence of a WP
31 - max-frequency: maximum operating clock frequency
32 - no-1-8-v: when present, denotes that 1.8v card voltage is not supported on
33 this system, even if the controller claims it is.
34 - cap-sd-highspeed: SD high-speed timing is supported
35 - cap-mmc-highspeed: MMC high-speed timing is supported
36 - sd-uhs-sdr12: SD UHS SDR12 speed is supported
37 - sd-uhs-sdr25: SD UHS SDR25 speed is supported
38 - sd-uhs-sdr50: SD UHS SDR50 speed is supported
39 - sd-uhs-sdr104: SD UHS SDR104 speed is supported
40 - sd-uhs-ddr50: SD UHS DDR50 speed is supported
41 - cap-power-off-card: powering off the card is safe
42 - cap-mmc-hw-reset: eMMC hardware reset is supported
43 - cap-sdio-irq: enable SDIO IRQ signalling on this interface
44 - full-pwr-cycle: full power cycle of the card is supported
45 - mmc-ddr-3_3v: eMMC high-speed DDR mode(3.3V I/O) is supported
46 - mmc-ddr-1_8v: eMMC high-speed DDR mode(1.8V I/O) is supported
47 - mmc-ddr-1_2v: eMMC high-speed DDR mode(1.2V I/O) is supported
48 - mmc-hs200-1_8v: eMMC HS200 mode(1.8V I/O) is supported
49 - mmc-hs200-1_2v: eMMC HS200 mode(1.2V I/O) is supported
50 - mmc-hs400-1_8v: eMMC HS400 mode(1.8V I/O) is supported
51 - mmc-hs400-1_2v: eMMC HS400 mode(1.2V I/O) is supported
52 - mmc-hs400-enhanced-strobe: eMMC HS400 enhanced strobe mode is supported
53 - dsr: Value the card's (optional) Driver Stage Register (DSR) should be
54 programmed with. Valid range: [0 .. 0xffff].
55 - no-sdio: controller is limited to send sdio cmd during initialization
56 - no-sd: controller is limited to send sd cmd during initialization
57 - no-mmc: controller is limited to send mmc cmd during initialization
58 - fixed-emmc-driver-type: for non-removable eMMC, enforce this driver type.
59 The value <n> is the driver type as specified in the eMMC specification
60 (table 206 in spec version 5.1).
61 - post-power-on-delay-ms : It was invented for MMC pwrseq-simple which could
62 be referred to mmc-pwrseq-simple.txt. But now it's reused as a tunable delay
63 waiting for I/O signalling and card power supply to be stable, regardless of
64 whether pwrseq-simple is used. Default to 10ms if no available.
66 *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line
67 polarity properties, we have to fix the meaning of the "normal" and "inverted"
68 line levels. We choose to follow the SDHCI standard, which specifies both those
69 lines as "active low." Therefore, using the "cd-inverted" property means, that
70 the CD line is active high, i.e. it is high, when a card is inserted. Similar
71 logic applies to the "wp-inverted" property.
73 CD and WP lines can be implemented on the hardware in one of two ways: as GPIOs,
74 specified in cd-gpios and wp-gpios properties, or as dedicated pins. Polarity of
75 dedicated pins can be specified, using *-inverted properties. GPIO polarity can
76 also be specified using the GPIO_ACTIVE_LOW flag. This creates an ambiguity
77 in the latter case. We choose to use the XOR logic for GPIO CD and WP lines.
78 This means, the two properties are "superimposed," for example leaving the
79 GPIO_ACTIVE_LOW flag clear and specifying the respective *-inverted property
80 property results in a double-inversion and actually means the "normal" line
81 polarity is in effect.
83 Optional SDIO properties:
84 - keep-power-in-suspend: Preserves card power during a suspend/resume cycle
85 - wakeup-source: Enables wake up of host system on SDIO IRQ assertion
86 (Legacy property supported: "enable-sdio-wakeup")
91 Controllers may implement power control from both the connected cards and
92 the IO signaling (for example to change to high-speed 1.8V signalling). If
93 the system supports this, then the following two properties should point
94 to valid regulator nodes:
96 - vqmmc-supply: supply node for IO line power
97 - vmmc-supply: supply node for card's power
103 System on chip designs may specify a specific MMC power sequence. To
104 successfully detect an (e)MMC/SD/SDIO card, that power sequence must be
105 maintained while initializing the card.
108 - mmc-pwrseq: phandle to the MMC power sequence node. See "mmc-pwrseq-*"
109 for documentation of MMC power sequence bindings.
112 Use of Function subnodes
113 ------------------------
115 On embedded systems the cards connected to a host may need additional
116 properties. These can be specified in subnodes to the host controller node.
117 The subnodes are identified by the standard 'reg' property.
118 Which information exactly can be specified depends on the bindings for the
119 SDIO function driver for the subnode, as specified by the compatible string.
121 Required host node properties when using function subnodes:
122 - #address-cells: should be one. The cell is the slot id.
123 - #size-cells: should be zero.
125 Required function subnode properties:
126 - reg: Must contain the SDIO function number of the function this subnode
127 describes. A value of 0 denotes the memory SD function, values from
128 1 to 7 denote the SDIO functions.
130 Optional function subnode properties:
131 - compatible: name of SDIO function following generic names recommended practice
140 compatible = "sdhci";
141 reg = <0xab000000 0x200>;
144 cd-gpios = <&gpio 69 0>;
146 wp-gpios = <&gpio 70 0>;
147 max-frequency = <50000000>;
148 keep-power-in-suspend;
150 mmc-pwrseq = <&sdhci0_pwrseq>
153 Example with sdio function subnode:
156 #address-cells = <1>;
159 pinctrl-names = "default";
160 pinctrl-0 = <&mmc3_pins_a>;
161 vmmc-supply = <®_vmmc3>;
164 mmc-pwrseq = <&sdhci0_pwrseq>
168 compatible = "brcm,bcm43xx-fmac";
169 interrupt-parent = <&pio>;
170 interrupts = <10 8>; /* PH10 / EINT10 */
171 interrupt-names = "host-wake";