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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
parent4397a2a80baefadc7454c70282c14d2af16ffe30 (diff)
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>
-rw-r--r--drivers/spi/Makefile3
-rw-r--r--drivers/spi/spi.c39
-rw-r--r--include/spi.h41
3 files changed, 83 insertions, 0 deletions
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index b8264df3a9b..45862ec9385 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -25,6 +25,9 @@ include $(TOPDIR)/config.mk
LIB := $(obj)libspi.o
+# There are many options which enable SPI, so make this library available
+COBJS-y += spi.o
+
COBJS-$(CONFIG_ALTERA_SPI) += altera_spi.o
COBJS-$(CONFIG_ANDES_SPI) += andes_spi.o
COBJS-$(CONFIG_ARMADA100_SPI) += armada100_spi.o
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
new file mode 100644
index 00000000000..cb36c5e6eb7
--- /dev/null
+++ b/drivers/spi/spi.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but without any warranty; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+
+void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
+ unsigned int cs)
+{
+ struct spi_slave *slave;
+ void *ptr;
+
+ ptr = malloc(size);
+ if (ptr) {
+ memset(ptr, '\0', size);
+ slave = (struct spi_slave *)(ptr + offset);
+ slave->bus = bus;
+ slave->cs = cs;
+ }
+
+ return ptr;
+}
diff --git a/include/spi.h b/include/spi.h
index 60e85db9a46..ebc96521602 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.
*