spi: omap3: fix claim/release bus within DM

The claim/release bus function must not reset the whole SPI core because
settings regarding wordlen, clock-frequency and so on made by
set_wordlen, set_mode, set_speed get lost with this action. Resulting in
a non-functional SPI.

Without DM the failure didn't came up since after the spi_reset within
claim bus all the setup (wordlen, mode, ...) was called, in DM they are
called by the spi uclass.

We change now the things as following for having a working SPI instance
in DM:

- move the spi_reset(...) to the probe call in DM for having a known
hardware state after probe. Without DM we don't have a probe call, so we
issue the reset as before during the claim_bus call.

- in release bus we just reset the modulctrl to the reset-value (spi-
slave)

Signed-off-by: Hannes Schmelzer <oe5hpm@oevsv.at>
Reviewed-by: Jagan Teki <jagan@openedev.com>

drivers/spi/omap3_spi.c

@@ -443,9 +443,6 @@ static void spi_reset(struct mcspi *regs)
 static void _omap3_spi_claim_bus(struct omap3_spi_priv *priv)
 {
 	unsigned int conf;
-
-	spi_reset(priv->regs);
-
 	/*
 	 * setup when switching from (reset default) slave mode
 	 * to single-channel master mode
@@ -480,6 +477,8 @@ int spi_claim_bus(struct spi_slave *slave)
 {
 	struct omap3_spi_priv *priv = to_omap3_spi(slave);
 
+	spi_reset(priv->regs);
+
 	_omap3_spi_claim_bus(priv);
 	_omap3_spi_set_wordlen(priv);
 	_omap3_spi_set_mode(priv);
@@ -492,8 +491,7 @@ void spi_release_bus(struct spi_slave *slave)
 {
 	struct omap3_spi_priv *priv = to_omap3_spi(slave);
 
-	/* Reset the SPI hardware */
-	spi_reset(priv->regs);
+	writel(OMAP3_MCSPI_MODULCTRL_MS, &priv->regs->modulctrl);
 }
 
 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
@@ -602,8 +600,7 @@ static int omap3_spi_release_bus(struct udevice *dev)
 	struct udevice *bus = dev->parent;
 	struct omap3_spi_priv *priv = dev_get_priv(bus);
 
-	/* Reset the SPI hardware */
-	spi_reset(priv->regs);
+	writel(OMAP3_MCSPI_MODULCTRL_MS, &priv->regs->modulctrl);
 
 	return 0;
 }
@@ -636,6 +633,9 @@ static int omap3_spi_probe(struct udevice *dev)
 	else
 		priv->pin_dir = MCSPI_PINDIR_D0_IN_D1_OUT;
 	priv->wordlen = SPI_DEFAULT_WORDLEN;
+
+	spi_reset(priv->regs);
+
 	return 0;
 }