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Showing posts from August, 2016

MMC2 Linux Device Tree Configuration For SD CARD on ARM PART ii

This blog entry is useful for ARM microprocessors running Kernel versions 4.4.16-ti-rt and newer. For configuring mmc2 on earlier kernel versions go to part I of this topic: MMC2 Linux Device Tree Configuration For ARM PART i

What has changed since earlier kernel releases?There has been a recent changes (end of last year) to the dt bindings for eDMA3.  Older kernels used DEPRECATED binding for DTS files.  The old bindings were ti,edma3-tpcc/ti,edma3-tptc.  And to get mmc2 (labeled mmc3 in dts files) to work properly you must use theti,edma-xbar-event-map property for edma:
&mmc3 { vmmc-supply = <&vmmcsd_fixed>; ti,dual-volt; ti,needs-special-reset; ti,needs-special-hs-handling; pinctrl-names = "default"; pinctrl-0 = <&mmc3_pins>; cd-gpios = <&gpio0 31 GPIO_ACTIVE_HIGH>; cd-inverted; bus-width = <4>; max-frequency = <25000000>; dmas = <&edma 12 &…