1 From 865d65a4097327385dd845260bfac37141303d2d Mon Sep 17 00:00:00 2001
2 From: campag <dave-lowe@ntlworld.com>
3 Date: Wed, 24 Feb 2016 16:45:42 +0000
4 Subject: [PATCH] BCM270X_DT: Add 1-bit SDIO using minimal pins...
6 ... for that mode: GPIOs 22-25.
8 arch/arm/boot/dts/overlays/README | 21 ++++++++++++++
9 arch/arm/boot/dts/overlays/sdio-1bit-overlay.dts | 36 ++++++++++++++++++++++++
10 2 files changed, 57 insertions(+)
11 create mode 100644 arch/arm/boot/dts/overlays/sdio-1bit-overlay.dts
13 --- a/arch/arm/boot/dts/overlays/README
14 +++ b/arch/arm/boot/dts/overlays/README
15 @@ -709,6 +709,27 @@ Params: overclock_50 SD Clock
16 bus_width Set the SDIO host bus width (default 4 bits)
20 +Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
21 + and enables 1-bit SDIO via GPIOs 22-25.
22 +Load: dtoverlay=sdio-1bit,<param>=<val>
23 +Params: overclock_50 SD Clock (in MHz) to use when the MMC framework
26 + sdio_overclock SDIO Clock (in MHz) to use when the MMC
27 + framework requests 50MHz
29 + force_pio Disable DMA support (default off)
31 + pio_limit Number of blocks above which to use DMA
34 + debug Enable debug output (default off)
36 + poll_once Disable SDIO-device polling every second
37 + (default on: polling once at boot-time)
41 Info: Tunes the bcm2835-sdhost SD/MMC driver
42 Load: dtoverlay=sdtweak,<param>=<val>
44 +++ b/arch/arm/boot/dts/overlays/sdio-1bit-overlay.dts
46 +/* Enable 1-bit SDIO from MMC interface via GPIOs 22-25. Includes sdhost overlay. */
48 +/include/ "sdhost-overlay.dts"
51 + compatible = "brcm,bcm2708";
55 + sdio_mmc: __overlay__ {
56 + compatible = "brcm,bcm2835-mmc";
57 + pinctrl-names = "default";
58 + pinctrl-0 = <&sdio_pins>;
61 + brcm,overclock-50 = <0>;
69 + sdio_pins: sdio_pins {
70 + brcm,pins = <22 23 24 25>;
71 + brcm,function = <7 7 7 7>; /* ALT3 = SD1 */
72 + brcm,pull = <0 2 2 2>;
78 + poll_once = <&sdio_mmc>,"non-removable?";
79 + sdio_overclock = <&sdio_mmc>,"brcm,overclock-50:0";