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authorJustin Waters <justin.waters@timesys.com>2009-06-17 10:09:00 -0400
committerJustin Waters <justin.waters@timesys.com>2009-06-17 10:09:00 -0400
commit4e35d9f7af6cb5d553511d6064f224885fd905f4 (patch)
tree7ae0aec6dffc515af7c84c1d25f9c4ec6d0bc9f6 /common/soft_spi.c
parent180a90abdae72587c0f679edf8991455e559440d (diff)
Diffstat (limited to 'common/soft_spi.c')
-rw-r--r--common/soft_spi.c124
1 files changed, 93 insertions, 31 deletions
diff --git a/common/soft_spi.c b/common/soft_spi.c
index e4250616c28..c13165030db 100644
--- a/common/soft_spi.c
+++ b/common/soft_spi.c
@@ -29,6 +29,8 @@
#if defined(CONFIG_SOFT_SPI)
+#include <malloc.h>
+
/*-----------------------------------------------------------------------
* Definitions
*/
@@ -39,6 +41,15 @@
#define PRINTD(fmt,args...)
#endif
+struct soft_spi_slave {
+ struct spi_slave slave;
+ unsigned int mode;
+};
+
+static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave)
+{
+ return container_of(slave, struct soft_spi_slave, slave);
+}
/*=====================================================================*/
/* Public Functions */
@@ -56,6 +67,57 @@ void spi_init (void)
#endif
}
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct soft_spi_slave *ss;
+
+ if (!spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ ss = malloc(sizeof(struct soft_spi_slave));
+ if (!ss)
+ return NULL;
+
+ ss->slave.bus = bus;
+ ss->slave.cs = cs;
+ ss->mode = mode;
+
+ /* TODO: Use max_hz to limit the SCK rate */
+
+ return &ss->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct soft_spi_slave *ss = to_soft_spi(slave);
+
+ free(ss);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+#ifdef CFG_IMMR
+ volatile immap_t *immr = (immap_t *)CFG_IMMR;
+#endif
+ struct soft_spi_slave *ss = to_soft_spi(slave);
+
+ /*
+ * Make sure the SPI clock is in idle state as defined for
+ * this slave.
+ */
+ if (ss->mode & SPI_CPOL)
+ SPI_SCL(1);
+ else
+ SPI_SCL(0);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ /* Nothing to do */
+}
/*-----------------------------------------------------------------------
* SPI transfer
@@ -68,50 +130,54 @@ void spi_init (void)
* and "din" can point to the same memory location, in which case the
* input data overwrites the output data (since both are buffered by
* temporary variables, this is OK).
- *
- * If the chipsel() function is not NULL, it is called with a parameter
- * of '1' (chip select active) at the start of the transfer and again with
- * a parameter of '0' at the end of the transfer.
- *
- * If the chipsel() function _is_ NULL, it the responsibility of the
- * caller to make the appropriate chip select active before calling
- * spi_xfer() and making it inactive after spi_xfer() returns.
*/
-int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din)
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
{
#ifdef CFG_IMMR
volatile immap_t *immr = (immap_t *)CFG_IMMR;
#endif
- uchar tmpdin = 0;
- uchar tmpdout = 0;
- int j;
+ struct soft_spi_slave *ss = to_soft_spi(slave);
+ uchar tmpdin = 0;
+ uchar tmpdout = 0;
+ const u8 *txd = dout;
+ u8 *rxd = din;
+ int cpol = ss->mode & SPI_CPOL;
+ int cpha = ss->mode & SPI_CPHA;
+ unsigned int j;
- PRINTD("spi_xfer: chipsel %08X dout %08X din %08X bitlen %d\n",
- (int)chipsel, *(uint *)dout, *(uint *)din, bitlen);
+ PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
+ slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen);
- if(chipsel != NULL) {
- (*chipsel)(1); /* select the target chip */
- }
+ if (flags & SPI_XFER_BEGIN)
+ spi_cs_activate(slave);
for(j = 0; j < bitlen; j++) {
/*
* Check if it is time to work on a new byte.
*/
if((j % 8) == 0) {
- tmpdout = *dout++;
+ tmpdout = *txd++;
if(j != 0) {
- *din++ = tmpdin;
+ *rxd++ = tmpdin;
}
tmpdin = 0;
}
- SPI_SCL(0);
+
+ if (!cpha)
+ SPI_SCL(!cpol);
SPI_SDA(tmpdout & 0x80);
SPI_DELAY;
- SPI_SCL(1);
+ if (cpha)
+ SPI_SCL(!cpol);
+ else
+ SPI_SCL(cpol);
+ tmpdin <<= 1;
+ tmpdin |= SPI_READ;
+ tmpdout <<= 1;
SPI_DELAY;
- tmpdin <<= 1;
- tmpdin |= SPI_READ;
- tmpdout <<= 1;
+ if (cpha)
+ SPI_SCL(cpol);
}
/*
* If the number of bits isn't a multiple of 8, shift the last
@@ -120,14 +186,10 @@ int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din)
*/
if((bitlen % 8) != 0)
tmpdin <<= 8 - (bitlen % 8);
- *din++ = tmpdin;
-
- SPI_SCL(0); /* SPI wants the clock left low for idle */
+ *rxd++ = tmpdin;
- if(chipsel != NULL) {
- (*chipsel)(0); /* deselect the target chip */
-
- }
+ if (flags & SPI_XFER_END)
+ spi_cs_deactivate(slave);
return(0);
}