[PATCH v3 1/3] mmc: core: consistent handling of initial values

[Johan Rudholm <johan.rudholm@axis.com>]

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>
---
 drivers/mmc/core/core.c |   47 ++++++++++++++++++++++-------------------------
 drivers/mmc/core/core.h |    1 +
 2 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index a32bea2..5bda29b 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -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);
 
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 443a584..d76597c 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -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)
 {
-- 
1.7.2.5