Add support for DT property "pd-timers" to allow users to define
platform specific values. For values that have not been explicitly
defined in DT using this attribute, default values will be set.
Therefore making this change backward compatible.

Cc: Badhri Jagan Sridharan <badhri@google.com>
Cc: linux-usb@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
---
 drivers/usb/typec/tcpm/tcpm.c | 110 ++++++++++++++++++++++++++++------
 1 file changed, 92 insertions(+), 18 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 4b02d6474259..596d19ff85ac 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -574,6 +574,31 @@ static const char * const pd_rev[] = {
 	[PD_REV30]		= "rev3",
 };
 
+/*
+ * Though "pd-timers" is a 1D array, it can be imagined as a table with 2
+ * columns, key at even index (that represents timer definition) & value
+ * at odd index (that represents timer values in ms).
+ */
+#define NUM_TIMER_TABLE_COLS		2
+
+/*
+ * PD Timer definitions for timers that can be tuned based on platform/board via DT.
+ * The timer definition value should always match that of macros defined in
+ * dt-bindings/usb/pd.h.
+ */
+enum pd_timer {
+	PD_TIMER_SINK_WAIT_CAP,
+	PD_TIMER_PS_SOURCE_OFF,
+	PD_TIMER_CC_DEBOUNCE,
+	PD_NUM_TIMERS
+};
+
+static u32 pd_timers[PD_NUM_TIMERS] = {
+	[PD_TIMER_SINK_WAIT_CAP] = PD_T_SINK_WAIT_CAP,
+	[PD_TIMER_PS_SOURCE_OFF] = PD_T_PS_SOURCE_OFF,
+	[PD_TIMER_CC_DEBOUNCE] = PD_T_CC_DEBOUNCE,
+};
+
 #define tcpm_cc_is_sink(cc) \
 	((cc) == TYPEC_CC_RP_DEF || (cc) == TYPEC_CC_RP_1_5 || \
 	 (cc) == TYPEC_CC_RP_3_0)
@@ -4601,7 +4626,7 @@ static void run_state_machine(struct tcpm_port *port)
 {
 	int ret;
 	enum typec_pwr_opmode opmode;
-	unsigned int msecs;
+	unsigned int msecs, timer_val_msecs;
 	enum tcpm_state upcoming_state;
 
 	if (port->tcpc->check_contaminant && port->state != CHECK_CONTAMINANT)
@@ -4637,17 +4662,18 @@ static void run_state_machine(struct tcpm_port *port)
 			tcpm_set_state(port, SNK_UNATTACHED, PD_T_DRP_SNK);
 		break;
 	case SRC_ATTACH_WAIT:
+		timer_val_msecs = pd_timers[PD_TIMER_CC_DEBOUNCE];
 		if (tcpm_port_is_debug(port))
 			tcpm_set_state(port, DEBUG_ACC_ATTACHED,
-				       PD_T_CC_DEBOUNCE);
+				       timer_val_msecs);
 		else if (tcpm_port_is_audio(port))
 			tcpm_set_state(port, AUDIO_ACC_ATTACHED,
-				       PD_T_CC_DEBOUNCE);
+				       timer_val_msecs);
 		else if (tcpm_port_is_source(port) && port->vbus_vsafe0v)
 			tcpm_set_state(port,
 				       tcpm_try_snk(port) ? SNK_TRY
 							  : SRC_ATTACHED,
-				       PD_T_CC_DEBOUNCE);
+				       timer_val_msecs);
 		break;
 
 	case SNK_TRY:
@@ -4698,7 +4724,7 @@ static void run_state_machine(struct tcpm_port *port)
 		}
 		break;
 	case SRC_TRYWAIT_DEBOUNCE:
-		tcpm_set_state(port, SRC_ATTACHED, PD_T_CC_DEBOUNCE);
+		tcpm_set_state(port, SRC_ATTACHED, pd_timers[PD_TIMER_CC_DEBOUNCE]);
 		break;
 	case SRC_TRYWAIT_UNATTACHED:
 		tcpm_set_state(port, SNK_UNATTACHED, 0);
@@ -4896,12 +4922,13 @@ static void run_state_machine(struct tcpm_port *port)
 			tcpm_set_state(port, SRC_UNATTACHED, PD_T_DRP_SRC);
 		break;
 	case SNK_ATTACH_WAIT:
+		timer_val_msecs = pd_timers[PD_TIMER_CC_DEBOUNCE];
 		if ((port->cc1 == TYPEC_CC_OPEN &&
 		     port->cc2 != TYPEC_CC_OPEN) ||
 		    (port->cc1 != TYPEC_CC_OPEN &&
 		     port->cc2 == TYPEC_CC_OPEN))
 			tcpm_set_state(port, SNK_DEBOUNCED,
-				       PD_T_CC_DEBOUNCE);
+				       timer_val_msecs);
 		else if (tcpm_port_is_disconnected(port))
 			tcpm_set_state(port, SNK_UNATTACHED,
 				       PD_T_PD_DEBOUNCE);
@@ -4941,7 +4968,7 @@ static void run_state_machine(struct tcpm_port *port)
 		break;
 	case SNK_TRYWAIT:
 		tcpm_set_cc(port, TYPEC_CC_RD);
-		tcpm_set_state(port, SNK_TRYWAIT_VBUS, PD_T_CC_DEBOUNCE);
+		tcpm_set_state(port, SNK_TRYWAIT_VBUS, pd_timers[PD_TIMER_CC_DEBOUNCE]);
 		break;
 	case SNK_TRYWAIT_VBUS:
 		/*
@@ -5014,7 +5041,7 @@ static void run_state_machine(struct tcpm_port *port)
 		break;
 	case SNK_DISCOVERY_DEBOUNCE:
 		tcpm_set_state(port, SNK_DISCOVERY_DEBOUNCE_DONE,
-			       PD_T_CC_DEBOUNCE);
+			       pd_timers[PD_TIMER_CC_DEBOUNCE]);
 		break;
 	case SNK_DISCOVERY_DEBOUNCE_DONE:
 		if (!tcpm_port_is_disconnected(port) &&
@@ -5032,6 +5059,7 @@ static void run_state_machine(struct tcpm_port *port)
 			tcpm_set_state(port, SNK_READY, 0);
 			break;
 		}
+		timer_val_msecs = pd_timers[PD_TIMER_SINK_WAIT_CAP];
 		/*
 		 * If VBUS has never been low, and we time out waiting
 		 * for source cap, try a soft reset first, in case we
@@ -5041,10 +5069,10 @@ static void run_state_machine(struct tcpm_port *port)
 		if (port->vbus_never_low) {
 			port->vbus_never_low = false;
 			tcpm_set_state(port, SNK_SOFT_RESET,
-				       PD_T_SINK_WAIT_CAP);
+				       timer_val_msecs);
 		} else {
 			tcpm_set_state(port, SNK_WAIT_CAPABILITIES_TIMEOUT,
-				       PD_T_SINK_WAIT_CAP);
+				       timer_val_msecs);
 		}
 		break;
 	case SNK_WAIT_CAPABILITIES_TIMEOUT:
@@ -5054,7 +5082,7 @@ static void run_state_machine(struct tcpm_port *port)
 		 * sending Source Capability messages after a soft reset. The
 		 * specification suggests to do a hard reset when no Source
 		 * capability message is received within PD_T_SINK_WAIT_CAP,
-		 * but that might effectively kil the machine's power source.
+		 * but that might effectively kill the machine's power source.
 		 *
 		 * This slightly diverges from the specification and tries to
 		 * recover from this by explicitly asking for the capabilities
@@ -5066,7 +5094,8 @@ static void run_state_machine(struct tcpm_port *port)
 		if (tcpm_pd_send_control(port, PD_CTRL_GET_SOURCE_CAP, TCPC_TX_SOP))
 			tcpm_set_state_cond(port, hard_reset_state(port), 0);
 		else
-			tcpm_set_state(port, hard_reset_state(port), PD_T_SINK_WAIT_CAP);
+			tcpm_set_state(port, hard_reset_state(port),
+				       pd_timers[PD_TIMER_SINK_WAIT_CAP]);
 		break;
 	case SNK_NEGOTIATE_CAPABILITIES:
 		port->pd_capable = true;
@@ -5203,7 +5232,7 @@ static void run_state_machine(struct tcpm_port *port)
 			tcpm_set_state(port, ACC_UNATTACHED, 0);
 		break;
 	case AUDIO_ACC_DEBOUNCE:
-		tcpm_set_state(port, ACC_UNATTACHED, PD_T_CC_DEBOUNCE);
+		tcpm_set_state(port, ACC_UNATTACHED, pd_timers[PD_TIMER_CC_DEBOUNCE]);
 		break;
 
 	/* Hard_Reset states */
@@ -5420,7 +5449,7 @@ static void run_state_machine(struct tcpm_port *port)
 		tcpm_set_state(port, ERROR_RECOVERY, 0);
 		break;
 	case FR_SWAP_SNK_SRC_TRANSITION_TO_OFF:
-		tcpm_set_state(port, ERROR_RECOVERY, PD_T_PS_SOURCE_OFF);
+		tcpm_set_state(port, ERROR_RECOVERY, pd_timers[PD_TIMER_PS_SOURCE_OFF]);
 		break;
 	case FR_SWAP_SNK_SRC_NEW_SINK_READY:
 		if (port->vbus_source)
@@ -5475,7 +5504,7 @@ static void run_state_machine(struct tcpm_port *port)
 		tcpm_set_cc(port, TYPEC_CC_RD);
 		/* allow CC debounce */
 		tcpm_set_state(port, PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED,
-			       PD_T_CC_DEBOUNCE);
+			       pd_timers[PD_TIMER_CC_DEBOUNCE]);
 		break;
 	case PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED:
 		/*
@@ -5510,7 +5539,7 @@ static void run_state_machine(struct tcpm_port *port)
 						       port->pps_data.active, 0);
 		tcpm_set_charge(port, false);
 		tcpm_set_state(port, hard_reset_state(port),
-			       PD_T_PS_SOURCE_OFF);
+			       pd_timers[PD_TIMER_PS_SOURCE_OFF]);
 		break;
 	case PR_SWAP_SNK_SRC_SOURCE_ON:
 		tcpm_enable_auto_vbus_discharge(port, true);
@@ -5666,7 +5695,7 @@ static void run_state_machine(struct tcpm_port *port)
 	case PORT_RESET_WAIT_OFF:
 		tcpm_set_state(port,
 			       tcpm_default_state(port),
-			       port->vbus_present ? PD_T_PS_SOURCE_OFF : 0);
+			       port->vbus_present ? pd_timers[PD_TIMER_PS_SOURCE_OFF] : 0);
 		break;
 
 	/* AMS intermediate state */
@@ -6157,7 +6186,7 @@ static void _tcpm_pd_vbus_vsafe0v(struct tcpm_port *port)
 	case SRC_ATTACH_WAIT:
 		if (tcpm_port_is_source(port))
 			tcpm_set_state(port, tcpm_try_snk(port) ? SNK_TRY : SRC_ATTACHED,
-				       PD_T_CC_DEBOUNCE);
+				       pd_timers[PD_TIMER_CC_DEBOUNCE]);
 		break;
 	case SRC_STARTUP:
 	case SRC_SEND_CAPABILITIES:
@@ -7273,6 +7302,47 @@ static int tcpm_fw_get_snk_vdos(struct tcpm_port *port, struct fwnode_handle *fw
 	return 0;
 }
 
+static int tcpm_fw_get_pd_timers(struct tcpm_port *port, struct fwnode_handle *fwnode)
+{
+	int ret, i, len;
+	u32 *buf;
+
+	/* pd-timers is an optional property */
+	ret = fwnode_property_count_u32(fwnode, "pd-timers");
+	if (ret < 0) {
+		tcpm_log(port, "Unable to locate 'pd-timers' connector property (%d)", ret);
+		return 0;
+	}
+
+	if (ret % NUM_TIMER_TABLE_COLS || ret == 0) {
+		tcpm_log(port, "Incorrect 'pd-timers' value. Found %d u32 elements in array", ret);
+		return 0;
+	}
+
+	len = min(ret, PD_NUM_TIMERS * NUM_TIMER_TABLE_COLS);
+
+	buf = kcalloc(len, sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = fwnode_property_read_u32_array(fwnode, "pd-timers", buf, len);
+	if (ret) {
+		dev_err(port->dev, "Unable to read pd-timers property (%d)", ret);
+		goto done;
+	}
+
+	for (i = 0; i < len - 1; i += NUM_TIMER_TABLE_COLS) {
+		if (buf[i] >= PD_NUM_TIMERS)
+			tcpm_log(port, "Unable to find timer index %d, skipping.", buf[i]);
+		else
+			pd_timers[buf[i]] = buf[i + 1];
+	}
+
+done:
+	kfree(buf);
+	return ret;
+}
+
 /* Power Supply access to expose source power information */
 enum tcpm_psy_online_states {
 	TCPM_PSY_OFFLINE = 0,
@@ -7608,6 +7678,10 @@ struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc)
 	init_completion(&port->pps_complete);
 	tcpm_debugfs_init(port);
 
+	err = tcpm_fw_get_pd_timers(port, tcpc->fwnode);
+	if (err)
+		goto out_destroy_wq;
+
 	err = tcpm_fw_get_caps(port, tcpc->fwnode);
 	if (err < 0)
 		goto out_destroy_wq;
-- 
2.46.0.598.g6f2099f65c-goog