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authorSimon Glass <sjg@chromium.org>2013-03-11 06:08:00 +0000
committerSimon Glass <sjg@chromium.org>2013-03-19 08:45:36 -0700
commitba6c3ce9bd0ac572592dc909878117dce219c564 (patch)
treea8b4225933d46d136fc76e5d033121124e491469 /include/spi.h
parent4397a2a80baefadc7454c70282c14d2af16ffe30 (diff)
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spi: Add function to allocate a new SPI slave
At present it is difficult to extend the SPI structure since all drivers allocate it themselves, and few of them zero all fields. Add a new function spi_alloc_slave() which can be used by SPI drivers to perform this allocation, and thus ensure that all drivers can better cope with SPI structure changes. Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'include/spi.h')
-rw-r--r--include/spi.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/include/spi.h b/include/spi.h
index 60e85db..ebc9652 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -62,6 +62,47 @@ struct spi_slave {
*/
void spi_init(void);
+/**
+ * spi_do_alloc_slave - Allocate a new SPI slave (internal)
+ *
+ * Allocate and zero all fields in the spi slave, and set the bus/chip
+ * select. Use the helper macro spi_alloc_slave() to call this.
+ *
+ * @offset: Offset of struct spi_slave within slave structure
+ * @size: Size of slave structure
+ * @bus: Bus ID of the slave chip.
+ * @cs: Chip select ID of the slave chip on the specified bus.
+ */
+void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
+ unsigned int cs);
+
+/**
+ * spi_alloc_slave - Allocate a new SPI slave
+ *
+ * Allocate and zero all fields in the spi slave, and set the bus/chip
+ * select.
+ *
+ * @_struct: Name of structure to allocate (e.g. struct tegra_spi). This
+ * structure must contain a member 'struct spi_slave *slave'.
+ * @bus: Bus ID of the slave chip.
+ * @cs: Chip select ID of the slave chip on the specified bus.
+ */
+#define spi_alloc_slave(_struct, bus, cs) \
+ spi_do_alloc_slave(offsetof(_struct, slave), \
+ sizeof(_struct), bus, cs)
+
+/**
+ * spi_alloc_slave_base - Allocate a new SPI slave with no private data
+ *
+ * Allocate and zero all fields in the spi slave, and set the bus/chip
+ * select.
+ *
+ * @bus: Bus ID of the slave chip.
+ * @cs: Chip select ID of the slave chip on the specified bus.
+ */
+#define spi_alloc_slave_base(bus, cs) \
+ spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
+
/*-----------------------------------------------------------------------
* Set up communications parameters for a SPI slave.
*