diff options
Diffstat (limited to 'Bindings/mmc/mmc.txt')
| -rw-r--r-- | Bindings/mmc/mmc.txt | 64 |
1 files changed, 63 insertions, 1 deletions
diff --git a/Bindings/mmc/mmc.txt b/Bindings/mmc/mmc.txt index 431716e37a39..438899e8829b 100644 --- a/Bindings/mmc/mmc.txt +++ b/Bindings/mmc/mmc.txt @@ -40,6 +40,8 @@ Optional properties: - mmc-hs200-1_2v: eMMC HS200 mode(1.2V I/O) is supported - mmc-hs400-1_8v: eMMC HS400 mode(1.8V I/O) is supported - mmc-hs400-1_2v: eMMC HS400 mode(1.2V I/O) is supported +- dsr: Value the card's (optional) Driver Stage Register (DSR) should be + programmed with. Valid range: [0 .. 0xffff]. *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line polarity properties, we have to fix the meaning of the "normal" and "inverted" @@ -62,7 +64,43 @@ Optional SDIO properties: - keep-power-in-suspend: Preserves card power during a suspend/resume cycle - enable-sdio-wakeup: Enables wake up of host system on SDIO IRQ assertion -Example: + +MMC power sequences: +-------------------- + +System on chip designs may specify a specific MMC power sequence. To +successfully detect an (e)MMC/SD/SDIO card, that power sequence must be +maintained while initializing the card. + +Optional property: +- mmc-pwrseq: phandle to the MMC power sequence node. See "mmc-pwrseq-*" + for documentation of MMC power sequence bindings. + + +Use of Function subnodes +------------------------ + +On embedded systems the cards connected to a host may need additional +properties. These can be specified in subnodes to the host controller node. +The subnodes are identified by the standard 'reg' property. +Which information exactly can be specified depends on the bindings for the +SDIO function driver for the subnode, as specified by the compatible string. + +Required host node properties when using function subnodes: +- #address-cells: should be one. The cell is the slot id. +- #size-cells: should be zero. + +Required function subnode properties: +- compatible: name of SDIO function following generic names recommended practice +- reg: Must contain the SDIO function number of the function this subnode + describes. A value of 0 denotes the memory SD function, values from + 1 to 7 denote the SDIO functions. + + +Examples +-------- + +Basic example: sdhci@ab000000 { compatible = "sdhci"; @@ -75,4 +113,28 @@ sdhci@ab000000 { max-frequency = <50000000>; keep-power-in-suspend; enable-sdio-wakeup; + mmc-pwrseq = <&sdhci0_pwrseq> } + +Example with sdio function subnode: + +mmc3: mmc@01c12000 { + #address-cells = <1>; + #size-cells = <0>; + + pinctrl-names = "default"; + pinctrl-0 = <&mmc3_pins_a>; + vmmc-supply = <®_vmmc3>; + bus-width = <4>; + non-removable; + mmc-pwrseq = <&sdhci0_pwrseq> + status = "okay"; + + brcmf: bcrmf@1 { + reg = <1>; + compatible = "brcm,bcm43xx-fmac"; + interrupt-parent = <&pio>; + interrupts = <10 8>; /* PH10 / EINT10 */ + interrupt-names = "host-wake"; + }; +}; |