cdx: add support for bus enable and disable

CDX bus needs to be disabled before updating/writing devices
in the FPGA. Once the devices are written, the bus shall be
rescanned. This change provides sysfs entry to enable/disable the
CDX bus.

Co-developed-by: Nipun Gupta <[email protected]>
Signed-off-by: Nipun Gupta <[email protected]>
Signed-off-by: Abhijit Gangurde <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c
index 0158f26533dd..0e1e35d91242 100644
--- a/drivers/cdx/controller/mcdi_functions.c
+++ b/drivers/cdx/controller/mcdi_functions.c
@@ -124,6 +124,30 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx,
 	return 0;
 }
 
+int cdx_mcdi_bus_enable(struct cdx_mcdi *cdx, u8 bus_num)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_BUS_UP_IN_LEN);
+	int ret;
+
+	MCDI_SET_DWORD(inbuf, CDX_BUS_UP_IN_BUS, bus_num);
+	ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_BUS_UP, inbuf, sizeof(inbuf),
+			   NULL, 0, NULL);
+
+	return ret;
+}
+
+int cdx_mcdi_bus_disable(struct cdx_mcdi *cdx, u8 bus_num)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_BUS_DOWN_IN_LEN);
+	int ret;
+
+	MCDI_SET_DWORD(inbuf, CDX_BUS_DOWN_IN_BUS, bus_num);
+	ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_BUS_DOWN, inbuf, sizeof(inbuf),
+			   NULL, 0, NULL);
+
+	return ret;
+}
+
 int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_RESET_IN_LEN);