For testing and hardware debugging a user may wish to override the
divisor at runtime. By setting fsi_master_aspeed.bus_div=N, the divisor
will be set to N, if 0 < N <= 0x3ff.
This is a module parameter and not a device tree option as it will only
need to be set when testing or debugging.
Reviewed-by: Eddie James <eajames@xxxxxxxxxxxxx>
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
---
drivers/fsi/fsi-master-aspeed.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
index f503f64ab32b..2531e826ba8b 100644
--- a/drivers/fsi/fsi-master-aspeed.c
+++ b/drivers/fsi/fsi-master-aspeed.c
@@ -87,6 +87,7 @@ static const u32 fsi_base = 0xa0000000;
#define FSI_DIVISOR_DEFAULT 1
#define FSI_DIVISOR_CABLED 2
static u16 aspeed_fsi_divisor = FSI_DIVISOR_DEFAULT;
+module_param_named(bus_div,aspeed_fsi_divisor, ushort, 0);
#define OPB_POLL_TIMEOUT 10000
@@ -454,9 +455,12 @@ static int tacoma_cabled_fsi_fixup(struct device *dev)
if (gpio) {
/*
* Cable signal integrity means we should run the bus
- * slightly slower
+ * slightly slower. Do not override if a kernel param
+ * has already overridden.
*/
- aspeed_fsi_divisor = FSI_DIVISOR_CABLED;
+ if (aspeed_fsi_divisor == FSI_DIVISOR_DEFAULT)
+ aspeed_fsi_divisor = FSI_DIVISOR_CABLED;
+
gpiod_direction_output(mux_gpio, 0);
dev_info(dev, "FSI configured for external cable\n");
} else {
--
2.27.0
