1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 3d09e0b69b73..1f8903d356e5 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -1217,6 +1217,33 @@ out:
         return status;
 }
 
+static int omap2_mcspi_prepare_message(struct spi_master *master,
+                                       struct spi_message *msg)
+{
+        struct omap2_mcspi      *mcspi = spi_master_get_devdata(master);
+        struct omap2_mcspi_regs *ctx = &mcspi->ctx;
+        struct omap2_mcspi_cs   *cs;
+
+        /* Only a single channel can have the FORCE bit enabled
+         * in its chconf0 register.
+         * Scan all channels and disable them except the current one.
+         * A FORCE can remain from a last transfer having cs_change enabled
+         */
+        list_for_each_entry(cs, &ctx->cs, node) {
+                if (msg->spi->controller_state == cs)
+                        continue;
+
+                if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
+                        cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
+                        writel_relaxed(cs->chconf0,
+                                        cs->base + OMAP2_MCSPI_CHCONF0);
+                        readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
+                }
+        }
+
+        return 0;
+}
+
 static int omap2_mcspi_transfer_one(struct spi_master *master,
                 struct spi_device *spi, struct spi_transfer *t)
 {
@@ -1344,6 +1371,7 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
         master->setup = omap2_mcspi_setup;
         master->auto_runtime_pm = true;
+        master->prepare_message = omap2_mcspi_prepare_message;
         master->transfer_one = omap2_mcspi_transfer_one;
         master->set_cs = omap2_mcspi_set_cs;
         master->cleanup = omap2_mcspi_cleanup;