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path: root/drivers/spi/mxc_spi.c
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Diffstat (limited to 'drivers/spi/mxc_spi.c')
-rw-r--r--drivers/spi/mxc_spi.c48
1 files changed, 25 insertions, 23 deletions
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 2d5f3850da8..026f680d80d 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -25,6 +25,11 @@ static unsigned long spi_bases[] = {
MXC_SPI_BASE_ADDRESSES
};
+__weak int board_spi_cs_gpio(unsigned bus, unsigned cs)
+{
+ return -1;
+}
+
#define OUT MXC_GPIO_DIRECTION_OUT
#define reg_read readl
@@ -371,31 +376,30 @@ void spi_init(void)
{
}
-static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs)
+/*
+ * Some SPI devices require active chip-select over multiple
+ * transactions, we achieve this using a GPIO. Still, the SPI
+ * controller has to be configured to use one of its own chipselects.
+ * To use this feature you have to implement board_spi_cs_gpio() to assign
+ * a gpio value for each cs (-1 if cs doesn't need to use gpio).
+ * You must use some unused on this SPI controller cs between 0 and 3.
+ */
+static int setup_cs_gpio(struct mxc_spi_slave *mxcs,
+ unsigned int bus, unsigned int cs)
{
int ret;
- /*
- * Some SPI devices require active chip-select over multiple
- * transactions, we achieve this using a GPIO. Still, the SPI
- * controller has to be configured to use one of its own chipselects.
- * To use this feature you have to call spi_setup_slave() with
- * cs = internal_cs | (gpio << 8), and you have to use some unused
- * on this SPI controller cs between 0 and 3.
- */
- if (cs > 3) {
- mxcs->gpio = cs >> 8;
- cs &= 3;
- ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol));
- if (ret) {
- printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
- return -EINVAL;
- }
- } else {
- mxcs->gpio = -1;
+ mxcs->gpio = board_spi_cs_gpio(bus, cs);
+ if (mxcs->gpio == -1)
+ return 0;
+
+ ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol));
+ if (ret) {
+ printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
+ return -EINVAL;
}
- return cs;
+ return 0;
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
@@ -415,14 +419,12 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0;
- ret = decode_cs(mxcs, cs);
+ ret = setup_cs_gpio(mxcs, bus, cs);
if (ret < 0) {
free(mxcs);
return NULL;
}
- cs = ret;
-
mxcs->base = spi_bases[bus];
ret = spi_cfg_mxc(mxcs, cs, max_hz, mode);