diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/usb/chipidea/otg.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c new file mode 100644 index 000000000..f25d4827f --- /dev/null +++ b/drivers/usb/chipidea/otg.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * otg.c - ChipIdea USB IP core OTG driver + * + * Copyright (C) 2013 Freescale Semiconductor, Inc. + * + * Author: Peter Chen + */ + +/* + * This file mainly handles otgsc register, OTG fsm operations for HNP and SRP + * are also included. + */ + +#include <linux/usb/otg.h> +#include <linux/usb/gadget.h> +#include <linux/usb/chipidea.h> + +#include "ci.h" +#include "bits.h" +#include "otg.h" +#include "otg_fsm.h" + +/** + * hw_read_otgsc returns otgsc register bits value. + * @mask: bitfield mask + */ +u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask) +{ + struct ci_hdrc_cable *cable; + u32 val = hw_read(ci, OP_OTGSC, mask); + + /* + * If using extcon framework for VBUS and/or ID signal + * detection overwrite OTGSC register value + */ + cable = &ci->platdata->vbus_extcon; + if (!IS_ERR(cable->edev)) { + if (cable->changed) + val |= OTGSC_BSVIS; + else + val &= ~OTGSC_BSVIS; + + if (cable->connected) + val |= OTGSC_BSV; + else + val &= ~OTGSC_BSV; + + if (cable->enabled) + val |= OTGSC_BSVIE; + else + val &= ~OTGSC_BSVIE; + } + + cable = &ci->platdata->id_extcon; + if (!IS_ERR(cable->edev)) { + if (cable->changed) + val |= OTGSC_IDIS; + else + val &= ~OTGSC_IDIS; + + if (cable->connected) + val &= ~OTGSC_ID; /* host */ + else + val |= OTGSC_ID; /* device */ + + if (cable->enabled) + val |= OTGSC_IDIE; + else + val &= ~OTGSC_IDIE; + } + + return val & mask; +} + +/** + * hw_write_otgsc updates target bits of OTGSC register. + * @mask: bitfield mask + * @data: to be written + */ +void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data) +{ + struct ci_hdrc_cable *cable; + + cable = &ci->platdata->vbus_extcon; + if (!IS_ERR(cable->edev)) { + if (data & mask & OTGSC_BSVIS) + cable->changed = false; + + /* Don't enable vbus interrupt if using external notifier */ + if (data & mask & OTGSC_BSVIE) { + cable->enabled = true; + data &= ~OTGSC_BSVIE; + } else if (mask & OTGSC_BSVIE) { + cable->enabled = false; + } + } + + cable = &ci->platdata->id_extcon; + if (!IS_ERR(cable->edev)) { + if (data & mask & OTGSC_IDIS) + cable->changed = false; + + /* Don't enable id interrupt if using external notifier */ + if (data & mask & OTGSC_IDIE) { + cable->enabled = true; + data &= ~OTGSC_IDIE; + } else if (mask & OTGSC_IDIE) { + cable->enabled = false; + } + } + + hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data); +} + +/** + * ci_otg_role - pick role based on ID pin state + * @ci: the controller + */ +enum ci_role ci_otg_role(struct ci_hdrc *ci) +{ + enum ci_role role = hw_read_otgsc(ci, OTGSC_ID) + ? CI_ROLE_GADGET + : CI_ROLE_HOST; + + return role; +} + +void ci_handle_vbus_change(struct ci_hdrc *ci) +{ + if (!ci->is_otg) + return; + + if (hw_read_otgsc(ci, OTGSC_BSV) && !ci->vbus_active) + usb_gadget_vbus_connect(&ci->gadget); + else if (!hw_read_otgsc(ci, OTGSC_BSV) && ci->vbus_active) + usb_gadget_vbus_disconnect(&ci->gadget); +} + +/** + * When we switch to device mode, the vbus value should be lower + * than OTGSC_BSV before connecting to host. + * + * @ci: the controller + * + * This function returns an error code if timeout + */ +static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci) +{ + unsigned long elapse = jiffies + msecs_to_jiffies(5000); + u32 mask = OTGSC_BSV; + + while (hw_read_otgsc(ci, mask)) { + if (time_after(jiffies, elapse)) { + dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n", + mask); + return -ETIMEDOUT; + } + msleep(20); + } + + return 0; +} + +static void ci_handle_id_switch(struct ci_hdrc *ci) +{ + enum ci_role role = ci_otg_role(ci); + + if (role != ci->role) { + dev_dbg(ci->dev, "switching from %s to %s\n", + ci_role(ci)->name, ci->roles[role]->name); + + ci_role_stop(ci); + + if (role == CI_ROLE_GADGET && + IS_ERR(ci->platdata->vbus_extcon.edev)) + /* + * Wait vbus lower than OTGSC_BSV before connecting + * to host. If connecting status is from an external + * connector instead of register, we don't need to + * care vbus on the board, since it will not affect + * external connector status. + */ + hw_wait_vbus_lower_bsv(ci); + + ci_role_start(ci, role); + /* vbus change may have already occurred */ + if (role == CI_ROLE_GADGET) + ci_handle_vbus_change(ci); + } +} +/** + * ci_otg_work - perform otg (vbus/id) event handle + * @work: work struct + */ +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; + } + + pm_runtime_get_sync(ci->dev); + + if (ci->id_event) { + ci->id_event = false; + ci_handle_id_switch(ci); + } + + if (ci->b_sess_valid_event) { + ci->b_sess_valid_event = false; + ci_handle_vbus_change(ci); + } + + pm_runtime_put_sync(ci->dev); + + enable_irq(ci->irq); +} + + +/** + * ci_hdrc_otg_init - initialize otg struct + * ci: the controller + */ +int ci_hdrc_otg_init(struct ci_hdrc *ci) +{ + INIT_WORK(&ci->work, ci_otg_work); + ci->wq = create_freezable_workqueue("ci_otg"); + if (!ci->wq) { + dev_err(ci->dev, "can't create workqueue\n"); + return -ENODEV; + } + + if (ci_otg_is_fsm_mode(ci)) + return ci_hdrc_otg_fsm_init(ci); + + return 0; +} + +/** + * ci_hdrc_otg_destroy - destroy otg struct + * ci: the controller + */ +void ci_hdrc_otg_destroy(struct ci_hdrc *ci) +{ + if (ci->wq) { + flush_workqueue(ci->wq); + destroy_workqueue(ci->wq); + } + /* Disable all OTG irq and clear status */ + hw_write_otgsc(ci, OTGSC_INT_EN_BITS | OTGSC_INT_STATUS_BITS, + OTGSC_INT_STATUS_BITS); + if (ci_otg_is_fsm_mode(ci)) + ci_hdrc_otg_fsm_remove(ci); +} |