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mmc: core: consistent handling of initial values

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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: Johan Rudholm <johanru@axis.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Johan Rudholm 2014-11-06 14:46:54 +01:00 committed by Ulf Hansson
parent 80412ca8ab
commit 2d079c43bc
2 changed files with 23 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
drivers/mmc/core/core.c
View File

@ -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);

1
drivers/mmc/core/core.h
View File

@ -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)
{