Change in coreboot[master]: drivers/intel/usb4/retimer: Add function to correct EC port mapping

[Maulik V Vaghela (Code Review)]

Maulik V Vaghela has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/59665 )

Change subject: drivers/intel/usb4/retimer: Add function to correct EC port mapping
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drivers/intel/usb4/retimer: Add function to correct EC port mapping

Currently coreboot interprets TCSS port number as per physical port
number while EC abstracts port number and provides indices as port number.
For example, if TCSS port 1 and 3 are enabled on the board, coreboot
will interpret port number as 0 and 2, but since only 2 ports are enabled
in the system EC will assign port number as 0 and 1.

This creates a port number mismatch while communicating between EC and
coreboot. This patch addresses issue where SoC can implement function
to map correct EC port as per port enabled in mainboard.

BUG=b:207057940
BRANCH=None
TEST=Check if code compiles successfully. Functionality will work once
function is implemented in SoC code.

Change-Id: Ia7a5e63838e6529196bd211516e4d665b084f79e
Signed-off-by: MAULIK V VAGHELA 
---
M src/drivers/intel/usb4/retimer/retimer.c
M src/drivers/intel/usb4/retimer/retimer.h
2 files changed, 26 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/65/59665/1

diff --git a/src/drivers/intel/usb4/retimer/retimer.c b/src/drivers/intel/usb4/retimer/retimer.c
index e549525..788df9e 100644
--- a/src/drivers/intel/usb4/retimer/retimer.c
+++ b/src/drivers/intel/usb4/retimer/retimer.c
@@ -396,7 +396,7 @@
    	/* Return (Buffer (One) { 0x0 }) */
    	acpigen_write_return_singleton_buffer(0x0);
    	acpigen_pop_len();
-		usb4_retimer_write_dsm(usb_port, INTEL_USB4_RETIMER_DSM_UUID,
+		usb4_retimer_write_dsm(ec_port, INTEL_USB4_RETIMER_DSM_UUID,
    		usb4_retimer_callbacks, ARRAY_SIZE(usb4_retimer_callbacks),
    		(void *)&config->dfp[dfp_port].power_gpio);
    	/* Default case: Return (Buffer (One) { 0x0 }) */
@@ -436,3 +436,18 @@
 __weak void ec_retimer_fw_update(uint8_t data)
 {
 }
+
+/*
+ * This function will convert CPU physical port mapping to abstract
+ * EC port mapping. For example, board might have enabled TCSS port 1
+ * and 3 as per physical port mapping. Since only 2 TCSS ports are enabled
+ * EC will name it as port 0 and port 1. So there will be mismatch when
+ * coreboot sends index for port 3.
+ * Each SoC code using retimer driver needs to implement this function
+ * since SoC will have physical port details.
+ */
+__weak uint8_t map_physical_port_to_ec_port(uint8_t usb_port)
+{
+	// By default assume that physical port index = Ec port index.
+	return usb_port;
+}
diff --git a/src/drivers/intel/usb4/retimer/retimer.h b/src/drivers/intel/usb4/retimer/retimer.h
index 5a040a0..3f136dd 100644
--- a/src/drivers/intel/usb4/retimer/retimer.h
+++ b/src/drivers/intel/usb4/retimer/retimer.h
@@ -30,5 +30,15 @@

const char *ec_retimer_fw_update_path(void);
 void ec_retimer_fw_update(uint8_t data);
+/*
+ * This function will convert CPU physical port mapping to abstract
+ * EC port mapping. For example, board might have enabled TCSS port 1
+ * and 3 as per physical port mapping. Since only 2 TCSS ports are enabled
+ * EC will name it as port 0 and port 1. So there will be mismatch when
+ * coreboot sends index for port 3.
+ * Each SoC code using retimer driver needs to implement this function
+ * since SoC will have physical port details.
+ */
+uint8_t map_physical_port_to_ec_port(uint8_t usb_port);

#endif /* _DRIVERS_INTEL_USB4_RETIMER_H_ */