usb_mux: retimer: mux as chained mux and retimer

This makes retimers appear as generic muxes.  By allowing a
chain of muxes they can be stacked up to the new configurations
that zork requires and will continue to work as they did before
on configurations that only have a single mux.

The code used to have two different arrays, 1) muxes and 2)
retimers.  On one of the zork configurations the processor
MUX stopped being the primary mux and the retimer took its
place.  In a different configuration of that same platform
it left the primary and secondary alone but the mux_set
FLIP operation had to be ignored.  Since the same
interfaces needed to be available for both it stopped making
sense to have two different structures and two different
methods of handling them.  This consolodates the two into
one.

The platforms that do not have retimers, this change will
not make any difference. For platforms like zork, it will
remove the retimers and make them chained muxes.  So
testing on trembyle makes sense to verify,

BUG=b:147593660
BRANCH=none
TEST=verify USB still works on trembyle

Change-Id: I286cf1e302f9bd3dd7e81098ec08514a2a009fe3
Signed-off-by: Denis Brockus <dbrockus@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2066794
Commit-Queue: Jett Rink <jettrink@chromium.org>
Reviewed-by: Edward Hill <ecgh@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>

2 files changed, 7 insertions, 13 deletions

diff --git a/board/trogdor/board.c b/board/trogdor/board.c
index 717392a1a2..c8d770fc37 100644
--- a/board/trogdor/board.c
+++ b/board/trogdor/board.c
@@ -266,12 +266,14 @@ const struct tcpc_config_t tcpc_config[CONFIG_USB_PD_PORT_MAX_COUNT] = {
  * to AP. But the TCPC chip is also needed to know the HPD status; otherwise,
  * the mux misbehaves.
  */
-struct usb_mux usb_muxes[CONFIG_USB_PD_PORT_MAX_COUNT] = {
+const struct usb_mux usb_muxes[CONFIG_USB_PD_PORT_MAX_COUNT] = {
 	{
+		.usb_port = 0,
 		.driver = &ps8xxx_usb_mux_driver,
 		.hpd_update = &ps8xxx_tcpc_update_hpd_status,
 	},
 	{
+		.usb_port = 1,
 		.driver = &ps8xxx_usb_mux_driver,
 		.hpd_update = &ps8xxx_tcpc_update_hpd_status,
 	}
@@ -328,8 +330,6 @@ DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_DEFAULT);
 
 void board_tcpc_init(void)
 {
-	int port;
-
 	/* Only reset TCPC if not sysjump */
 	if (!system_jumped_to_this_image()) {
 		/* TODO(crosbug.com/p/61098): How long do we need to wait? */
@@ -347,11 +347,8 @@ void board_tcpc_init(void)
 	 * Initialize HPD to low; after sysjump SOC needs to see
 	 * HPD pulse to enable video path
 	 */
-	for (port = 0; port < CONFIG_USB_PD_PORT_MAX_COUNT; port++) {
-		const struct usb_mux *mux = &usb_muxes[port];
-
-		mux->hpd_update(port, 0, 0);
-	}
+	for (int port = 0; port < CONFIG_USB_PD_PORT_MAX_COUNT; ++port)
+		usb_mux_hpd_update(port, 0, 0);
 }
 DECLARE_HOOK(HOOK_INIT, board_tcpc_init, HOOK_PRIO_INIT_I2C+1);
 
diff --git a/board/trogdor/usb_pd_policy.c b/board/trogdor/usb_pd_policy.c
index c88768f63a..6840ae919e 100644
--- a/board/trogdor/usb_pd_policy.c
+++ b/board/trogdor/usb_pd_policy.c
@@ -152,7 +152,6 @@ __override int svdm_dp_attention(int port, uint32_t *payload)
 	enum gpio_signal hpd = GPIO_DP_HOT_PLUG_DET;
 	int lvl = PD_VDO_DPSTS_HPD_LVL(payload[1]);
 	int irq = PD_VDO_DPSTS_HPD_IRQ(payload[1]);
-	const struct usb_mux *mux = &usb_muxes[port];
 	int cur_lvl = gpio_get_level(hpd);
 
 	dp_status[port] = payload[1];
@@ -217,7 +216,7 @@ __override int svdm_dp_attention(int port, uint32_t *payload)
 		pd_notify_dp_alt_mode_entry();
 
 	/* Configure TCPC for the HPD event, for proper muxing */
-	mux->hpd_update(port, lvl, irq);
+	usb_mux_hpd_update(port, lvl, irq);
 
 	/* Signal AP for the HPD event, through GPIO to AP */
 	if (irq & cur_lvl) {
@@ -249,8 +248,6 @@ __override int svdm_dp_attention(int port, uint32_t *payload)
 
 __override void svdm_exit_dp_mode(int port)
 {
-	const struct usb_mux *mux = &usb_muxes[port];
-
 	/* Disconnect the DP port selection mux. */
 	gpio_set_level(GPIO_DP_MUX_OE_L, 1);
 
@@ -258,7 +255,7 @@ __override void svdm_exit_dp_mode(int port)
 	svdm_safe_dp_mode(port);
 
 	/* Signal AP for the HPD low event */
-	mux->hpd_update(port, 0, 0);
+	usb_mux_hpd_update(port, 0, 0);
 	gpio_set_level(GPIO_DP_HOT_PLUG_DET, 0);
 }
 #endif /* CONFIG_USB_PD_ALT_MODE_DFP */