[U-Boot] [PATCH] spi: designware_spi: Add reset ctrl to driver
Ley Foon Tan
ley.foon.tan at intel.com
Thu Sep 6 14:22:47 UTC 2018
Add code to reset all reset signals as in SPI DT node. A reset property
is an optional feature, so only print out a warning and do not fail if a
reset property is not present.
If a reset property is discovered, then use it to deassert, thus
bringing the IP out of reset.
Release reset when _remove().
Signed-off-by: Ley Foon Tan <ley.foon.tan at intel.com>
---
drivers/spi/designware_spi.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/drivers/spi/designware_spi.c b/drivers/spi/designware_spi.c
index d8b73ea..b73ec38 100644
--- a/drivers/spi/designware_spi.c
+++ b/drivers/spi/designware_spi.c
@@ -17,6 +17,7 @@
#include <malloc.h>
#include <spi.h>
#include <fdtdec.h>
+#include <reset.h>
#include <linux/compat.h>
#include <linux/iopoll.h>
#include <asm/io.h>
@@ -111,6 +112,8 @@ struct dw_spi_priv {
void *tx_end;
void *rx;
void *rx_end;
+
+ struct reset_ctl_bulk resets;
};
static inline u32 dw_read(struct dw_spi_priv *priv, u32 offset)
@@ -231,6 +234,33 @@ err_rate:
return -EINVAL;
}
+static int dw_spi_reset(struct udevice *bus)
+{
+ int ret;
+ struct dw_spi_priv *priv = dev_get_priv(bus);
+
+ ret = reset_get_bulk(bus, &priv->resets);
+ if (ret) {
+ /* Return 0 if error due to !CONFIG_DM_RESET and reset
+ * DT property is not present.
+ */
+ if (ret == -ENOENT || ret == -ENOTSUPP)
+ return 0;
+
+ dev_warn(bus, "Can't get reset: %d\n", ret);
+ return ret;
+ }
+
+ ret = reset_deassert_bulk(&priv->resets);
+ if (ret) {
+ reset_release_bulk(&priv->resets);
+ dev_err(bus, "Failed to reset: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
static int dw_spi_probe(struct udevice *bus)
{
struct dw_spi_platdata *plat = dev_get_platdata(bus);
@@ -244,6 +274,10 @@ static int dw_spi_probe(struct udevice *bus)
if (ret)
return ret;
+ ret = dw_spi_reset(bus);
+ if (ret)
+ return ret;
+
/* Currently only bits_per_word == 8 supported */
priv->bits_per_word = 8;
@@ -478,6 +512,13 @@ static int dw_spi_set_mode(struct udevice *bus, uint mode)
return 0;
}
+static int dw_spi_remove(struct udevice *bus)
+{
+ struct dw_spi_priv *priv = dev_get_priv(bus);
+
+ return reset_release_bulk(&priv->resets);
+}
+
static const struct dm_spi_ops dw_spi_ops = {
.xfer = dw_spi_xfer,
.set_speed = dw_spi_set_speed,
@@ -502,4 +543,5 @@ U_BOOT_DRIVER(dw_spi) = {
.platdata_auto_alloc_size = sizeof(struct dw_spi_platdata),
.priv_auto_alloc_size = sizeof(struct dw_spi_priv),
.probe = dw_spi_probe,
+ .remove = dw_spi_remove,
};
--
2.2.2
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