mmc: dt: Allow to specify that no write protect signal is present (19f44246) · Commits · 戴 / test

Allow to specify in the device-tree that no physical write-protect signal is connected to a particular instance of a MMC controller. Setting the property will cause the core will assume that the SD card is always read-write. The name for the new property is 'disable-wp' and was chosen based on the property with the same function from the Synopsys designware mobile storage host controller DT bindings specification. Signed-off-by:

Lars-Peter Clausen <lars@metafoo.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: Pawel Moll <pawel.moll@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> Cc: Kumar Gala <galak@codeaurora.org> Signed-off-by:

Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/mmc.txt

+5 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,11 @@ Optional properties:
		below for the case, when a GPIO is used for the CD line
		- wp-inverted: when present, polarity on the WP line is inverted. See the note
		below for the case, when a GPIO is used for the WP line
		- disable-wp: When set no physical WP line is present. This property should
		only be specified when the controller has a dedicated write-protect
		detection logic. If a GPIO is always used for the write-protect detection
		logic it is sufficient to not specify wp-gpios property in the absence of a WP
		line.
		- max-frequency: maximum operating clock frequency
		- no-1-8-v: when present, denotes that 1.8v card voltage is not supported on
		this system, even if the controller claims it is.

drivers/mmc/core/host.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -484,6 +484,9 @@ int mmc_of_parse(struct mmc_host *host)
		else if (ret != -ENOENT)
		return ret;

		if (of_property_read_bool(np, "disable-wp"))
		host->caps2 \|= MMC_CAP2_NO_WRITE_PROTECT;

		/* See the comment on CD inversion above */
		if (ro_cap_invert ^ ro_gpio_invert)
		host->caps2 \|= MMC_CAP2_RO_ACTIVE_HIGH;

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