[PATCH RFC 2/2] staging: fbtft: fix 9-bit SPI support detection

[Stefan Wahren]

Since bits_per_word isn't usually checked during SPI setup the 9-bit
support must be checked manually.

Signed-off-by: Stefan Wahren <stefan.wah...@i2se.com>
---
 drivers/staging/fbtft/fbtft-core.c |    7 +++++++
 drivers/staging/fbtft/flexfb.c     |    7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/staging/fbtft/fbtft-core.c 
b/drivers/staging/fbtft/fbtft-core.c
index 3638554..bd71487 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -1438,6 +1438,13 @@ int fbtft_probe_common(struct fbtft_display *display,
        if (par->spi && display->buswidth == 9) {
                par->spi->bits_per_word = 9;
                ret = spi_setup(par->spi);
+               if (!ret) {
+                       struct spi_master *ma = par->spi->master;
+
+                       if (!(ma->bits_per_word_mask & SPI_BPW_MASK(9)))
+                               ret = -EINVAL;
+               }
+
                if (ret) {
                        dev_warn(&par->spi->dev,
                                "9-bit SPI not available, emulating using 
8-bit.\n");
diff --git a/drivers/staging/fbtft/flexfb.c b/drivers/staging/fbtft/flexfb.c
index 09fd15d..a54a8d9 100644
--- a/drivers/staging/fbtft/flexfb.c
+++ b/drivers/staging/fbtft/flexfb.c
@@ -465,6 +465,13 @@ static int flexfb_probe_common(struct spi_device *sdev,
                        par->fbtftops.write_vmem = fbtft_write_vmem16_bus9;
                        sdev->bits_per_word = 9;
                        ret = spi_setup(sdev);
+                       if (!ret) {
+                               struct spi_master *ma = par->spi->master;
+
+                               if (!(ma->bits_per_word_mask & SPI_BPW_MASK(9)))
+                                       ret = -EINVAL;
+                       }
+
                        if (ret) {
                                dev_warn(dev,
                                        "9-bit SPI not available, emulating 
using 8-bit.\n");
-- 
1.7.9.5

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