Factor out the SD card shutdown sequence to a dedicated
mmc_spi_shutdownsequence() function in order to make mmc_spi_set_ios()
more readable, and also for symmetry with mmc_spi_initsequence() which
is already a dedicated function.
Signed-off-by: Antonio Ospite <ospite@xxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/mmc_spi.c | 90 +++++++++++++++++++++++--------------------
1 files changed, 48 insertions(+), 42 deletions(-)
diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 49f5725..9eae23c 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -1176,6 +1176,51 @@ static void mmc_spi_initsequence(struct mmc_spi_host *host)
}
}
+/* See Section 6.4.2, in SD "Simplified Physical Layer Specification 2.0"
+ *
+ * If powering down, ground all card inputs to avoid power delivery from data
+ * lines! On a shared SPI bus, this will probably be temporary; 6.4.2 of
+ * the simplified SD spec says this must last at least 1msec.
+ *
+ * - Clock low means CPOL 0, e.g. mode 0
+ * - MOSI low comes from writing zero
+ * - Chipselect is usually active low...
+ */
+static void mmc_spi_shutdownsequence(struct mmc_spi_host *host)
+{
+ int mres;
+ u8 nullbyte = 0;
+
+ host->spi->mode &= ~(SPI_CPOL|SPI_CPHA);
+ mres = spi_setup(host->spi);
+ if (mres < 0)
+ dev_dbg(&host->spi->dev,
+ "switch to SPI mode 0 failed\n");
+
+ if (spi_write(host->spi, &nullbyte, 1) < 0)
+ dev_dbg(&host->spi->dev,
+ "put spi signals to low failed\n");
+
+ /*
+ * Now clock should be low due to spi mode 0;
+ * MOSI should be low because of written 0x00;
+ * chipselect should be low (it is active low)
+ * power supply is off, so now MMC is off too!
+ *
+ * FIXME no, chipselect can be high since the
+ * device is inactive and SPI_CS_HIGH is clear...
+ */
+ msleep(10);
+ if (mres == 0) {
+ host->spi->mode |= (SPI_CPOL|SPI_CPHA);
+ mres = spi_setup(host->spi);
+ if (mres < 0)
+ dev_dbg(&host->spi->dev,
+ "switch back to SPI mode 3"
+ " failed\n");
+ }
+}
+
static char *mmc_powerstring(u8 power_mode)
{
switch (power_mode) {
@@ -1215,49 +1260,10 @@ static void mmc_spi_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
if (ios->power_mode == MMC_POWER_ON)
mmc_spi_initsequence(host);
- /* If powering down, ground all card inputs to avoid power
- * delivery from data lines! On a shared SPI bus, this
- * will probably be temporary; 6.4.2 of the simplified SD
- * spec says this must last at least 1msec.
- *
- * - Clock low means CPOL 0, e.g. mode 0
- * - MOSI low comes from writing zero
- * - Chipselect is usually active low...
- */
+ /* See 6.4.2 in the simplified SD card physical spec 2.0 */
if (mmc_spi_canpower(host) &&
- ios->power_mode == MMC_POWER_OFF) {
- int mres;
- u8 nullbyte = 0;
-
- host->spi->mode &= ~(SPI_CPOL|SPI_CPHA);
- mres = spi_setup(host->spi);
- if (mres < 0)
- dev_dbg(&host->spi->dev,
- "switch to SPI mode 0 failed\n");
-
- if (spi_write(host->spi, &nullbyte, 1) < 0)
- dev_dbg(&host->spi->dev,
- "put spi signals to low failed\n");
-
- /*
- * Now clock should be low due to spi mode 0;
- * MOSI should be low because of written 0x00;
- * chipselect should be low (it is active low)
- * power supply is off, so now MMC is off too!
- *
- * FIXME no, chipselect can be high since the
- * device is inactive and SPI_CS_HIGH is clear...
- */
- msleep(10);
- if (mres == 0) {
- host->spi->mode |= (SPI_CPOL|SPI_CPHA);
- mres = spi_setup(host->spi);
- if (mres < 0)
- dev_dbg(&host->spi->dev,
- "switch back to SPI mode 3"
- " failed\n");
- }
- }
+ ios->power_mode == MMC_POWER_OFF)
+ mmc_spi_shutdownsequence(host);
host->power_mode = ios->power_mode;
}
--
1.7.4.4
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