spi: imx: add a device specific prepare_message callback

This is just preparatory work which allows to move some initialisation
that currently is done in the per transfer hook .config to an earlier
point in time in the next few patches. There is no change in behaviour
introduced by this patch.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-imx.c

@@ -59,6 +59,7 @@ struct spi_imx_data;
 
 struct spi_imx_devtype_data {
 	void (*intctrl)(struct spi_imx_data *, int);
+	int (*prepare_message)(struct spi_imx_data *, struct spi_message *);
 	int (*config)(struct spi_device *);
 	void (*trigger)(struct spi_imx_data *);
 	int (*rx_available)(struct spi_imx_data *);
@@ -486,6 +487,12 @@ static void mx51_ecspi_disable(struct spi_imx_data *spi_imx)
 	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
 }
 
+static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
+				      struct spi_message *msg)
+{
+	return 0;
+}
+
 static int mx51_ecspi_config(struct spi_device *spi)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
@@ -659,6 +666,12 @@ static void mx31_trigger(struct spi_imx_data *spi_imx)
 	writel(reg, spi_imx->base + MXC_CSPICTRL);
 }
 
+static int mx31_prepare_message(struct spi_imx_data *spi_imx,
+				struct spi_message *msg)
+{
+	return 0;
+}
+
 static int mx31_config(struct spi_device *spi)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
@@ -755,6 +768,12 @@ static void mx21_trigger(struct spi_imx_data *spi_imx)
 	writel(reg, spi_imx->base + MXC_CSPICTRL);
 }
 
+static int mx21_prepare_message(struct spi_imx_data *spi_imx,
+				struct spi_message *msg)
+{
+	return 0;
+}
+
 static int mx21_config(struct spi_device *spi)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
@@ -824,6 +843,12 @@ static void mx1_trigger(struct spi_imx_data *spi_imx)
 	writel(reg, spi_imx->base + MXC_CSPICTRL);
 }
 
+static int mx1_prepare_message(struct spi_imx_data *spi_imx,
+			       struct spi_message *msg)
+{
+	return 0;
+}
+
 static int mx1_config(struct spi_device *spi)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
@@ -858,6 +883,7 @@ static void mx1_reset(struct spi_imx_data *spi_imx)
 
 static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
 	.intctrl = mx1_intctrl,
+	.prepare_message = mx1_prepare_message,
 	.config = mx1_config,
 	.trigger = mx1_trigger,
 	.rx_available = mx1_rx_available,
@@ -871,6 +897,7 @@ static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
 
 static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
 	.intctrl = mx21_intctrl,
+	.prepare_message = mx21_prepare_message,
 	.config = mx21_config,
 	.trigger = mx21_trigger,
 	.rx_available = mx21_rx_available,
@@ -885,6 +912,7 @@ static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
 static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
 	/* i.mx27 cspi shares the functions with i.mx21 one */
 	.intctrl = mx21_intctrl,
+	.prepare_message = mx21_prepare_message,
 	.config = mx21_config,
 	.trigger = mx21_trigger,
 	.rx_available = mx21_rx_available,
@@ -898,6 +926,7 @@ static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
 
 static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
 	.intctrl = mx31_intctrl,
+	.prepare_message = mx31_prepare_message,
 	.config = mx31_config,
 	.trigger = mx31_trigger,
 	.rx_available = mx31_rx_available,
@@ -912,6 +941,7 @@ static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
 static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
 	/* i.mx35 and later cspi shares the functions with i.mx31 one */
 	.intctrl = mx31_intctrl,
+	.prepare_message = mx31_prepare_message,
 	.config = mx31_config,
 	.trigger = mx31_trigger,
 	.rx_available = mx31_rx_available,
@@ -925,6 +955,7 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
 
 static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.intctrl = mx51_ecspi_intctrl,
+	.prepare_message = mx51_ecspi_prepare_message,
 	.config = mx51_ecspi_config,
 	.trigger = mx51_ecspi_trigger,
 	.rx_available = mx51_ecspi_rx_available,
@@ -940,6 +971,7 @@ static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 
 static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
 	.intctrl = mx51_ecspi_intctrl,
+	.prepare_message = mx51_ecspi_prepare_message,
 	.config = mx51_ecspi_config,
 	.trigger = mx51_ecspi_trigger,
 	.rx_available = mx51_ecspi_rx_available,
@@ -1492,7 +1524,13 @@ spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg)
 		return ret;
 	}
 
-	return 0;
+	ret = spi_imx->devtype_data->prepare_message(spi_imx, msg);
+	if (ret) {
+		clk_disable(spi_imx->clk_ipg);
+		clk_disable(spi_imx->clk_per);
+	}
+
+	return ret;
 }
 
 static int