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usb: chipidea: OTG HNP and SRP fsm implementation
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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>
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Li Jun authored and Greg Kroah-Hartman committed Apr 24, 2014
1 parent e287b67 commit 4dcf720
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Showing 5 changed files with 294 additions and 8 deletions.
24 changes: 18 additions & 6 deletions drivers/usb/chipidea/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,6 @@
* - Not Supported: 15 & 16 (ISO)
*
* TODO List
* - OTG
* - Interrupt Traffic
* - GET_STATUS(device) - always reports 0
* - Gadget API (majority of optional features)
Expand Down Expand Up @@ -74,6 +73,7 @@
#include "host.h"
#include "debug.h"
#include "otg.h"
#include "otg_fsm.h"

/* Controller register map */
static const u8 ci_regs_nolpm[] = {
Expand Down Expand Up @@ -411,8 +411,14 @@ static irqreturn_t ci_irq(int irq, void *data)
irqreturn_t ret = IRQ_NONE;
u32 otgsc = 0;

if (ci->is_otg)
if (ci->is_otg) {
otgsc = hw_read_otgsc(ci, ~0);
if (ci_otg_is_fsm_mode(ci)) {
ret = ci_otg_fsm_irq(ci);
if (ret == IRQ_HANDLED)
return ret;
}
}

/*
* Handle id change interrupt, it indicates device/host function
Expand Down Expand Up @@ -691,10 +697,13 @@ static int ci_hdrc_probe(struct platform_device *pdev)
if (ci->role == CI_ROLE_GADGET)
ci_handle_vbus_change(ci);

ret = ci_role_start(ci, ci->role);
if (ret) {
dev_err(dev, "can't start %s role\n", ci_role(ci)->name);
goto stop;
if (!ci_otg_is_fsm_mode(ci)) {
ret = ci_role_start(ci, ci->role);
if (ret) {
dev_err(dev, "can't start %s role\n",
ci_role(ci)->name);
goto stop;
}
}

platform_set_drvdata(pdev, ci);
Expand All @@ -703,6 +712,9 @@ static int ci_hdrc_probe(struct platform_device *pdev)
if (ret)
goto stop;

if (ci_otg_is_fsm_mode(ci))
ci_hdrc_otg_fsm_start(ci);

ret = dbg_create_files(ci);
if (!ret)
return 0;
Expand Down
9 changes: 7 additions & 2 deletions drivers/usb/chipidea/otg.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -11,8 +11,8 @@
*/

/*
* This file mainly handles otgsc register, it may include OTG operation
* in the future.
* This file mainly handles otgsc register, OTG fsm operations for HNP and SRP
* are also included.
*/

#include <linux/usb/otg.h>
Expand Down Expand Up @@ -91,6 +91,11 @@ static void ci_otg_work(struct work_struct *work)
{
struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work);

if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) {
enable_irq(ci->irq);
return;
}

if (ci->id_event) {
ci->id_event = false;
ci_handle_id_switch(ci);
Expand Down
243 changes: 243 additions & 0 deletions drivers/usb/chipidea/otg_fsm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -93,6 +97,33 @@ static void ci_otg_del_timer(struct ci_hdrc *ci, enum ci_otg_fsm_timer_index t)
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)
{
Expand Down Expand Up @@ -394,6 +425,218 @@ static struct otg_fsm_ops ci_otg_ops = {
.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;
Expand Down
18 changes: 18 additions & 0 deletions drivers/usb/chipidea/otg_fsm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,9 @@ struct ci_otg_fsm_timer_list {
#ifdef CONFIG_USB_OTG_FSM

int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci);
int ci_otg_fsm_work(struct ci_hdrc *ci);
irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci);
void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci);

#else

Expand All @@ -100,6 +103,21 @@ static inline int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci)
return 0;
}

static inline int ci_otg_fsm_work(struct ci_hdrc *ci)
{
return -ENXIO;
}

static inline irqreturn_t ci_otg_fsm_irq(struct ci_hdrc *ci)
{
return IRQ_NONE;
}

static inline void ci_hdrc_otg_fsm_start(struct ci_hdrc *ci)
{

}

#endif

#endif /* __DRIVERS_USB_CHIPIDEA_OTG_FSM_H */
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