imx spi: Use gpio as chip selects

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 27 insertions, 0 deletions

diff --git a/include/asm-arm/arch-imx/spi.h b/include/asm-arm/arch-imx/spi.h
new file mode 100644
index 0000000000..08be445e8e
--- /dev/null
+++ b/include/asm-arm/arch-imx/spi.h
@@ -0,0 +1,27 @@
+
+#ifndef __MACH_SPI_H_
+#define __MACH_SPI_H_
+
+/*
+ * struct spi_imx_master - device.platform_data for SPI controller devices.
+ * @chipselect: Array of chipselects for this master. Numbers >= 0 mean gpio
+ *              pins, numbers < 0 mean internal CSPI chipselects according
+ *              to MXC_SPI_CS(). Normally you want to use gpio based chip
+ *              selects as the CSPI module tries to be intelligent about
+ *              when to assert the chipselect: The CSPI module deasserts the
+ *              chipselect once it runs out of input data. The other problem
+ *              is that it is not possible to mix between high active and low
+ *              active chipselects on one single bus using the internal
+ *              chipselects. Unfortunately Freescale decided to put some
+ *              chipselects on dedicated pins which are not usable as gpios,
+ *              so we have to support the internal chipselects.
+ * @num_chipselect: ARRAY_SIZE(chipselect)
+ */
+struct spi_imx_master {
+	int	*chipselect;
+	int	num_chipselect;
+};
+
+#define MXC_SPI_CS(no)	((no) - 32)
+
+#endif /* __MACH_SPI_H_*/