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Commit 2d079c43 authored by Johan Rudholm's avatar Johan Rudholm Committed by Ulf Hansson
Browse files

mmc: core: consistent handling of initial values 



mmc_do_hw_reset(), mmc_power_up() and mmc_power_off() all set similar
initial values for bus_mode, bus_width, chip_select and timing. Let's
make this handling simpler and more consistent by sticking them
together in a common function. This will introduce small changes in
behavior in the following places:

mmc_power_off():

  For SPI hosts, explicitly set bus_mode = MMC_BUSMODE_PUSHPULL and
  chip_select = MMC_CS_HIGH, before we left them as they were.

  For non-SPI hosts, set bus_mode = MMC_BUSMODE_PUSHPULL instead of
  MMC_BUSMODE_OPENDRAIN as before.

  These two changes should not be a problem since the device will be
  powered off anyway.

mmc_do_hw_reset():

  Always set bus_mode = MMC_BUSMODE_PUSHPULL, as required by SD/SDIO
  cards. MMC cards require MMC_BUSMODE_OPENDRAIN, but this is taken
  care of by mmc_init_card() and mmc_attach_mmc().

Signed-off-by: default avatarJohan Rudholm <johanru@axis.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 80412ca8

drivers/mmc/core/core.c

+22 −25
Original line number Diff line number Diff line
@@ -1099,6 +1099,22 @@ void mmc_set_bus_width(struct mmc_host *host, unsigned int width) 
	mmc_host_clk_release(host);

}



/*

 * Set initial state after a power cycle or a hw_reset.

 */

void mmc_set_initial_state(struct mmc_host *host)

{

	if (mmc_host_is_spi(host))

		host->ios.chip_select = MMC_CS_HIGH;

	else

		host->ios.chip_select = MMC_CS_DONTCARE;

	host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;

	host->ios.bus_width = MMC_BUS_WIDTH_1;

	host->ios.timing = MMC_TIMING_LEGACY;



	mmc_set_ios(host);

}



/**

 * mmc_vdd_to_ocrbitnum - Convert a voltage to the OCR bit number

 * @vdd:	voltage (mV)
@@ -1537,15 +1553,9 @@ void mmc_power_up(struct mmc_host *host, u32 ocr) 
	mmc_host_clk_hold(host);



	host->ios.vdd = fls(ocr) - 1;

	if (mmc_host_is_spi(host))

		host->ios.chip_select = MMC_CS_HIGH;

	else

		host->ios.chip_select = MMC_CS_DONTCARE;

	host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;

	host->ios.power_mode = MMC_POWER_UP;

	host->ios.bus_width = MMC_BUS_WIDTH_1;

	host->ios.timing = MMC_TIMING_LEGACY;

	mmc_set_ios(host);

	/* Set initial state and call mmc_set_ios */

	mmc_set_initial_state(host);



	/* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */

	if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330) == 0)
@@ -1585,14 +1595,9 @@ void mmc_power_off(struct mmc_host *host) 
	host->ios.clock = 0;

	host->ios.vdd = 0;



	if (!mmc_host_is_spi(host)) {

		host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;

		host->ios.chip_select = MMC_CS_DONTCARE;

	}

	host->ios.power_mode = MMC_POWER_OFF;

	host->ios.bus_width = MMC_BUS_WIDTH_1;

	host->ios.timing = MMC_TIMING_LEGACY;

	mmc_set_ios(host);

	/* Set initial state and call mmc_set_ios */

	mmc_set_initial_state(host);



	/*

	 * Some configurations, such as the 802.11 SDIO card in the OLPC
@@ -2278,16 +2283,8 @@ static int mmc_do_hw_reset(struct mmc_host *host, int check) 
		}

	}



	if (mmc_host_is_spi(host)) {

		host->ios.chip_select = MMC_CS_HIGH;

		host->ios.bus_mode = MMC_BUSMODE_PUSHPULL;

	} else {

		host->ios.chip_select = MMC_CS_DONTCARE;

		host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;

	}

	host->ios.bus_width = MMC_BUS_WIDTH_1;

	host->ios.timing = MMC_TIMING_LEGACY;

	mmc_set_ios(host);

	/* Set initial state and call mmc_set_ios */

	mmc_set_initial_state(host);



	mmc_host_clk_release(host);

drivers/mmc/core/core.h

+1 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type); 
void mmc_power_up(struct mmc_host *host, u32 ocr);

void mmc_power_off(struct mmc_host *host);

void mmc_power_cycle(struct mmc_host *host, u32 ocr);

void mmc_set_initial_state(struct mmc_host *host);



static inline void mmc_delay(unsigned int ms)

{