usb: chipidea: OTG HNP and SRP fsm implementation
USB OTG interrupt handling and fsm transitions according to USB OTG
and EH 2.0.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Li Jun <b47624@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/chipidea/otg_fsm.c b/drivers/usb/chipidea/otg_fsm.c
index bb64fb4..67902a1 100644
--- a/drivers/usb/chipidea/otg_fsm.c
+++ b/drivers/usb/chipidea/otg_fsm.c
@@ -13,6 +13,10 @@
/*
* This file mainly handles OTG fsm, it includes OTG fsm operations
* for HNP and SRP.
+ *
+ * TODO List
+ * - ADP
+ * - OTG test device
*/
#include <linux/usb/otg.h>
@@ -93,6 +97,33 @@
hw_write_otgsc(ci, OTGSC_1MSIE, 0);
}
+/*
+ * Reduce timer count by 1, and find timeout conditions.
+ * Called by otg 1ms timer interrupt
+ */
+static inline int ci_otg_tick_timer(struct ci_hdrc *ci)
+{
+ struct ci_otg_fsm_timer *tmp_timer, *del_tmp;
+ struct list_head *active_timers = &ci->fsm_timer->active_timers;
+ int expired = 0;
+
+ list_for_each_entry_safe(tmp_timer, del_tmp, active_timers, list) {
+ tmp_timer->count--;
+ /* check if timer expires */
+ if (!tmp_timer->count) {
+ list_del(&tmp_timer->list);
+ tmp_timer->function(ci, tmp_timer->data);
+ expired = 1;
+ }
+ }
+
+ /* disable 1ms irq if there is no any timer active */
+ if ((expired == 1) && list_empty(active_timers))
+ hw_write_otgsc(ci, OTGSC_1MSIE, 0);
+
+ return expired;
+}
+
/* The timeout callback function to set time out bit */
static void set_tmout(void *ptr, unsigned long indicator)
{
@@ -394,6 +425,218 @@
.start_gadget = ci_otg_start_gadget,
};
+int ci_otg_fsm_work(struct ci_hdrc *ci)
+{
+ /*
+ * Don't do fsm transition for B device
+ * when there is no gadget class driver
+ */
+ if (ci->fsm.id && !(ci->driver) &&
+ ci->transceiver->state < OTG_STATE_A_IDLE)
+ return 0;
+
+ if (otg_statemachine(&ci->fsm)) {
+ if (ci->transceiver->state == OTG_STATE_A_IDLE) {
+ /*
+ * Further state change for cases:
+ * a_idle to b_idle; or
+ * a_idle to a_wait_vrise due to ID change(1->0), so
+ * B-dev becomes A-dev can try to start new session
+ * consequently; or
+ * a_idle to a_wait_vrise when power up
+ */
+ if ((ci->fsm.id) || (ci->id_event) ||
+ (ci->fsm.power_up)) {
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ }
+ if (ci->id_event)
+ ci->id_event = false;
+ } else if (ci->transceiver->state == OTG_STATE_B_IDLE) {
+ if (ci->fsm.b_sess_vld) {
+ ci->fsm.power_up = 0;
+ /*
+ * Further transite to b_periphearl state
+ * when register gadget driver with vbus on
+ */
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ }
+ }
+ }
+ return 0;
+}
+
+/*
+ * Update fsm variables in each state if catching expected interrupts,
+ * called by otg fsm isr.
+ */
+static void ci_otg_fsm_event(struct ci_hdrc *ci)
+{
+ u32 intr_sts, otg_bsess_vld, port_conn;
+ struct otg_fsm *fsm = &ci->fsm;
+
+ intr_sts = hw_read_intr_status(ci);
+ otg_bsess_vld = hw_read_otgsc(ci, OTGSC_BSV);
+ port_conn = hw_read(ci, OP_PORTSC, PORTSC_CCS);
+
+ switch (ci->transceiver->state) {
+ case OTG_STATE_A_WAIT_BCON:
+ if (port_conn) {
+ fsm->b_conn = 1;
+ fsm->a_bus_req = 1;
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ }
+ break;
+ case OTG_STATE_B_IDLE:
+ if (otg_bsess_vld && (intr_sts & USBi_PCI) && port_conn) {
+ fsm->b_sess_vld = 1;
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ }
+ break;
+ case OTG_STATE_B_PERIPHERAL:
+ if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
+ fsm->a_bus_suspend = 1;
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ } else if (intr_sts & USBi_PCI) {
+ if (fsm->a_bus_suspend == 1)
+ fsm->a_bus_suspend = 0;
+ }
+ break;
+ case OTG_STATE_B_HOST:
+ if ((intr_sts & USBi_PCI) && !port_conn) {
+ fsm->a_conn = 0;
+ fsm->b_bus_req = 0;
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ ci_otg_add_timer(ci, B_SESS_VLD);
+ }
+ break;
+ case OTG_STATE_A_PERIPHERAL:
+ if (intr_sts & USBi_SLI) {
+ fsm->b_bus_suspend = 1;
+ /*
+ * Init a timer to know how long this suspend
+ * will contine, if time out, indicates B no longer
+ * wants to be host role
+ */
+ ci_otg_add_timer(ci, A_BIDL_ADIS);
+ }
+
+ if (intr_sts & USBi_URI)
+ ci_otg_del_timer(ci, A_BIDL_ADIS);
+
+ if (intr_sts & USBi_PCI) {
+ if (fsm->b_bus_suspend == 1) {
+ ci_otg_del_timer(ci, A_BIDL_ADIS);
+ fsm->b_bus_suspend = 0;
+ }
+ }
+ break;
+ case OTG_STATE_A_SUSPEND:
+ if ((intr_sts & USBi_PCI) && !port_conn) {
+ fsm->b_conn = 0;
+
+ /* if gadget driver is binded */
+ if (ci->driver) {
+ /* A device to be peripheral mode */
+ ci->gadget.is_a_peripheral = 1;
+ }
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ }
+ break;
+ case OTG_STATE_A_HOST:
+ if ((intr_sts & USBi_PCI) && !port_conn) {
+ fsm->b_conn = 0;
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ }
+ break;
+ case OTG_STATE_B_WAIT_ACON:
+ if ((intr_sts & USBi_PCI) && port_conn) {
+ fsm->a_conn = 1;
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ }
+ break;
+ default:
+ break;
+ }
+}
+
+/*
+ * ci_otg_irq - otg fsm related irq handling
+ * and also update otg fsm variable by monitoring usb host and udc
+ * state change interrupts.
+ * @ci: ci_hdrc
+ */
+irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
+{
+ irqreturn_t retval = IRQ_NONE;
+ u32 otgsc, otg_int_src = 0;
+ struct otg_fsm *fsm = &ci->fsm;
+
+ otgsc = hw_read_otgsc(ci, ~0);
+ otg_int_src = otgsc & OTGSC_INT_STATUS_BITS & (otgsc >> 8);
+ fsm->id = (otgsc & OTGSC_ID) ? 1 : 0;
+
+ if (otg_int_src) {
+ if (otg_int_src & OTGSC_1MSIS) {
+ hw_write_otgsc(ci, OTGSC_1MSIS, OTGSC_1MSIS);
+ retval = ci_otg_tick_timer(ci);
+ return IRQ_HANDLED;
+ } else if (otg_int_src & OTGSC_DPIS) {
+ hw_write_otgsc(ci, OTGSC_DPIS, OTGSC_DPIS);
+ fsm->a_srp_det = 1;
+ fsm->a_bus_drop = 0;
+ } else if (otg_int_src & OTGSC_IDIS) {
+ hw_write_otgsc(ci, OTGSC_IDIS, OTGSC_IDIS);
+ if (fsm->id == 0) {
+ fsm->a_bus_drop = 0;
+ fsm->a_bus_req = 1;
+ ci->id_event = true;
+ }
+ } else if (otg_int_src & OTGSC_BSVIS) {
+ hw_write_otgsc(ci, OTGSC_BSVIS, OTGSC_BSVIS);
+ if (otgsc & OTGSC_BSV) {
+ fsm->b_sess_vld = 1;
+ ci_otg_del_timer(ci, B_SSEND_SRP);
+ ci_otg_del_timer(ci, B_SRP_FAIL);
+ fsm->b_ssend_srp = 0;
+ } else {
+ fsm->b_sess_vld = 0;
+ if (fsm->id)
+ ci_otg_add_timer(ci, B_SSEND_SRP);
+ }
+ } else if (otg_int_src & OTGSC_AVVIS) {
+ hw_write_otgsc(ci, OTGSC_AVVIS, OTGSC_AVVIS);
+ if (otgsc & OTGSC_AVV) {
+ fsm->a_vbus_vld = 1;
+ } else {
+ fsm->a_vbus_vld = 0;
+ fsm->b_conn = 0;
+ }
+ }
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+ return IRQ_HANDLED;
+ }
+
+ ci_otg_fsm_event(ci);
+
+ return retval;
+}
+
+void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
+{
+ disable_irq_nosync(ci->irq);
+ queue_work(ci->wq, &ci->work);
+}
+
int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
{
int retval = 0;