diff options
| -rw-r--r-- | drivers/staging/greybus/Makefile | 4 | ||||
| -rw-r--r-- | drivers/staging/greybus/arche-apb-ctrl.c | 16 | ||||
| -rw-r--r-- | drivers/staging/greybus/arche-platform.c | 71 | ||||
| -rw-r--r-- | drivers/staging/greybus/arche_platform.h | 9 | ||||
| -rw-r--r-- | drivers/staging/greybus/greybus.h | 2 | ||||
| -rw-r--r-- | drivers/staging/greybus/interface.c | 55 | ||||
| -rw-r--r-- | drivers/staging/greybus/interface.h | 5 | ||||
| -rw-r--r-- | drivers/staging/greybus/timesync.c | 1021 | ||||
| -rw-r--r-- | drivers/staging/greybus/timesync.h | 41 | ||||
| -rw-r--r-- | drivers/staging/greybus/timesync_platform.c | 77 |
10 files changed, 1288 insertions, 13 deletions
diff --git a/drivers/staging/greybus/Makefile b/drivers/staging/greybus/Makefile index f7fe4d512015..981569dc86a7 100644 --- a/drivers/staging/greybus/Makefile +++ b/drivers/staging/greybus/Makefile @@ -10,7 +10,9 @@ greybus-y := core.o \ svc.o \ svc_watchdog.o \ bootrom.o \ - operation.o + operation.o \ + timesync.o \ + timesync_platform.o gb-gbphy-y := gbphy.o diff --git a/drivers/staging/greybus/arche-apb-ctrl.c b/drivers/staging/greybus/arche-apb-ctrl.c index a9d78a85939a..fce6a187ecfe 100644 --- a/drivers/staging/greybus/arche-apb-ctrl.c +++ b/drivers/staging/greybus/arche-apb-ctrl.c @@ -90,7 +90,7 @@ static int coldboot_seq(struct platform_device *pdev) } } - gpio_set_value(apb->boot_ret_gpio, 0); + apb_bootret_deassert(dev); /* On DB3 clock was not mandatory */ if (gpio_is_valid(apb->clk_en_gpio)) @@ -184,6 +184,20 @@ static void poweroff_seq(struct platform_device *pdev) /* TODO: May have to send an event to SVC about this exit */ } +void apb_bootret_assert(struct device *dev) +{ + struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev); + + gpio_set_value(apb->boot_ret_gpio, 1); +} + +void apb_bootret_deassert(struct device *dev) +{ + struct arche_apb_ctrl_drvdata *apb = dev_get_drvdata(dev); + + gpio_set_value(apb->boot_ret_gpio, 0); +} + int apb_ctrl_coldboot(struct device *dev) { return coldboot_seq(to_platform_device(dev)); diff --git a/drivers/staging/greybus/arche-platform.c b/drivers/staging/greybus/arche-platform.c index f47ea4670d25..31c952454cff 100644 --- a/drivers/staging/greybus/arche-platform.c +++ b/drivers/staging/greybus/arche-platform.c @@ -22,6 +22,7 @@ #include <linux/suspend.h> #include <linux/time.h> #include "arche_platform.h" +#include "greybus.h" #include <linux/usb/usb3613.h> @@ -34,6 +35,7 @@ enum svc_wakedetect_state { WD_STATE_STANDBYBOOT_TRIG, /* As of now not used ?? */ WD_STATE_COLDBOOT_START, /* Cold boot process started */ WD_STATE_STANDBYBOOT_START, /* Not used */ + WD_STATE_TIMESYNC, }; struct arche_platform_drvdata { @@ -57,13 +59,27 @@ struct arche_platform_drvdata { int wake_detect_irq; spinlock_t wake_lock; /* Protect wake_detect_state */ struct mutex platform_state_mutex; /* Protect state */ + wait_queue_head_t wq; /* WQ for arche_pdata->state */ unsigned long wake_detect_start; struct notifier_block pm_notifier; struct device *dev; + struct gb_timesync_svc *timesync_svc_pdata; }; -/* Requires calling context to hold arche_pdata->spinlock */ +static int arche_apb_bootret_assert(struct device *dev, void *data) +{ + apb_bootret_assert(dev); + return 0; +} + +static int arche_apb_bootret_deassert(struct device *dev, void *data) +{ + apb_bootret_deassert(dev); + return 0; +} + +/* Requires calling context to hold arche_pdata->platform_state_mutex */ static void arche_platform_set_state(struct arche_platform_drvdata *arche_pdata, enum arche_platform_state state) { @@ -94,7 +110,8 @@ static void arche_platform_set_state(struct arche_platform_drvdata *arche_pdata, * satisfy the requested state-transition or -EINVAL for all other * state-transition requests. */ -int arche_platform_change_state(enum arche_platform_state state) +int arche_platform_change_state(enum arche_platform_state state, + struct gb_timesync_svc *timesync_svc_pdata) { struct arche_platform_drvdata *arche_pdata; struct platform_device *pdev; @@ -118,11 +135,6 @@ int arche_platform_change_state(enum arche_platform_state state) mutex_lock(&arche_pdata->platform_state_mutex); spin_lock_irqsave(&arche_pdata->wake_lock, flags); - if (arche_pdata->wake_detect_state != WD_STATE_IDLE) { - dev_err(arche_pdata->dev, - "driver busy with wake/detect line ops\n"); - goto exit; - } if (arche_pdata->state == state) { ret = 0; @@ -131,10 +143,27 @@ int arche_platform_change_state(enum arche_platform_state state) switch (state) { case ARCHE_PLATFORM_STATE_TIME_SYNC: - disable_irq(arche_pdata->wake_detect_irq); + if (arche_pdata->state != ARCHE_PLATFORM_STATE_ACTIVE) { + ret = -EINVAL; + goto exit; + } + if (arche_pdata->wake_detect_state != WD_STATE_IDLE) { + dev_err(arche_pdata->dev, + "driver busy with wake/detect line ops\n"); + goto exit; + } + device_for_each_child(arche_pdata->dev, NULL, + arche_apb_bootret_assert); + arche_pdata->wake_detect_state = WD_STATE_TIMESYNC; break; case ARCHE_PLATFORM_STATE_ACTIVE: - enable_irq(arche_pdata->wake_detect_irq); + if (arche_pdata->state != ARCHE_PLATFORM_STATE_TIME_SYNC) { + ret = -EINVAL; + goto exit; + } + device_for_each_child(arche_pdata->dev, NULL, + arche_apb_bootret_deassert); + arche_pdata->wake_detect_state = WD_STATE_IDLE; break; case ARCHE_PLATFORM_STATE_OFF: case ARCHE_PLATFORM_STATE_STANDBY: @@ -147,7 +176,11 @@ int arche_platform_change_state(enum arche_platform_state state) "invalid state transition request\n"); goto exit; } + arche_pdata->timesync_svc_pdata = timesync_svc_pdata; arche_platform_set_state(arche_pdata, state); + if (state == ARCHE_PLATFORM_STATE_ACTIVE) + wake_up(&arche_pdata->wq); + ret = 0; exit: spin_unlock_irqrestore(&arche_pdata->wake_lock, flags); @@ -252,6 +285,11 @@ static irqreturn_t arche_platform_wd_irq(int irq, void *devid) spin_lock_irqsave(&arche_pdata->wake_lock, flags); + if (arche_pdata->wake_detect_state == WD_STATE_TIMESYNC) { + gb_timesync_irq(arche_pdata->timesync_svc_pdata); + goto exit; + } + if (gpio_get_value(arche_pdata->wake_detect_gpio)) { /* wake/detect rising */ @@ -293,6 +331,7 @@ static irqreturn_t arche_platform_wd_irq(int irq, void *devid) } } +exit: spin_unlock_irqrestore(&arche_pdata->wake_lock, flags); return IRQ_HANDLED; @@ -402,7 +441,17 @@ static ssize_t state_store(struct device *dev, struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev); int ret = 0; +retry: mutex_lock(&arche_pdata->platform_state_mutex); + if (arche_pdata->state == ARCHE_PLATFORM_STATE_TIME_SYNC) { + mutex_unlock(&arche_pdata->platform_state_mutex); + ret = wait_event_interruptible( + arche_pdata->wq, + arche_pdata->state != ARCHE_PLATFORM_STATE_TIME_SYNC); + if (ret) + return ret; + goto retry; + } if (sysfs_streq(buf, "off")) { if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF) @@ -610,6 +659,7 @@ static int arche_platform_probe(struct platform_device *pdev) spin_lock_init(&arche_pdata->wake_lock); mutex_init(&arche_pdata->platform_state_mutex); + init_waitqueue_head(&arche_pdata->wq); arche_pdata->wake_detect_irq = gpio_to_irq(arche_pdata->wake_detect_gpio); @@ -653,6 +703,9 @@ static int arche_platform_probe(struct platform_device *pdev) goto err_populate; } + /* Register callback pointer */ + arche_platform_change_state_cb = arche_platform_change_state; + dev_info(dev, "Device registered successfully\n"); return 0; diff --git a/drivers/staging/greybus/arche_platform.h b/drivers/staging/greybus/arche_platform.h index 0f2d29208f7f..bd12345b82a2 100644 --- a/drivers/staging/greybus/arche_platform.h +++ b/drivers/staging/greybus/arche_platform.h @@ -10,6 +10,8 @@ #ifndef __ARCHE_PLATFORM_H #define __ARCHE_PLATFORM_H +#include "timesync.h" + enum arche_platform_state { ARCHE_PLATFORM_STATE_OFF, ARCHE_PLATFORM_STATE_ACTIVE, @@ -18,8 +20,11 @@ enum arche_platform_state { ARCHE_PLATFORM_STATE_TIME_SYNC, }; -int arche_platform_change_state(enum arche_platform_state state); +int arche_platform_change_state(enum arche_platform_state state, + struct gb_timesync_svc *pdata); +extern int (*arche_platform_change_state_cb)(enum arche_platform_state state, + struct gb_timesync_svc *pdata); int __init arche_apb_init(void); void __exit arche_apb_exit(void); @@ -28,5 +33,7 @@ int apb_ctrl_coldboot(struct device *dev); int apb_ctrl_fw_flashing(struct device *dev); int apb_ctrl_standby_boot(struct device *dev); void apb_ctrl_poweroff(struct device *dev); +void apb_bootret_assert(struct device *dev); +void apb_bootret_deassert(struct device *dev); #endif /* __ARCHE_PLATFORM_H */ diff --git a/drivers/staging/greybus/greybus.h b/drivers/staging/greybus/greybus.h index e0b194c097a8..154dfd11e93b 100644 --- a/drivers/staging/greybus/greybus.h +++ b/drivers/staging/greybus/greybus.h @@ -33,7 +33,7 @@ #include "bundle.h" #include "connection.h" #include "operation.h" - +#include "timesync.h" /* Matches up with the Greybus Protocol specification document */ #define GREYBUS_VERSION_MAJOR 0x00 diff --git a/drivers/staging/greybus/interface.c b/drivers/staging/greybus/interface.c index 577d15fb5bd2..3eb8754961f1 100644 --- a/drivers/staging/greybus/interface.c +++ b/drivers/staging/greybus/interface.c @@ -865,6 +865,61 @@ void gb_interface_disable(struct gb_interface *intf) intf->enabled = false; } +/* + * Enable TimeSync on an Interface control connection. + * + * Locking: Takes and releases the interface mutex. + */ +int gb_interface_timesync_enable(struct gb_interface *intf, u8 count, + u64 frame_time, u32 strobe_delay, u32 refclk) +{ + int ret = -ENODEV; + + mutex_lock(&intf->mutex); + if (intf->enabled) { + ret = gb_control_timesync_enable(intf->control, count, + frame_time, strobe_delay, + refclk); + } + mutex_unlock(&intf->mutex); + return ret; +} + +/* + * Disable TimeSync on an Interface control connection. + * + * Locking: Takes and releases the interface mutex. + */ +int gb_interface_timesync_disable(struct gb_interface *intf) +{ + int ret = -ENODEV; + + mutex_lock(&intf->mutex); + if (intf->enabled) + ret = gb_control_timesync_disable(intf->control); + mutex_unlock(&intf->mutex); + return ret; +} + +/* + * Transmit the Authoritative FrameTime via an Interface control connection. + * + * Locking: Takes and releases the interface mutex. + */ +int gb_interface_timesync_authoritative(struct gb_interface *intf, + u64 *frame_time) +{ + int ret = -ENODEV; + + mutex_lock(&intf->mutex); + if (intf->enabled) { + ret = gb_control_timesync_authoritative(intf->control, + frame_time); + } + mutex_unlock(&intf->mutex); + return ret; +} + /* Register an interface. */ int gb_interface_add(struct gb_interface *intf) { diff --git a/drivers/staging/greybus/interface.h b/drivers/staging/greybus/interface.h index 603f146dce42..8796c55b7ffd 100644 --- a/drivers/staging/greybus/interface.h +++ b/drivers/staging/greybus/interface.h @@ -58,6 +58,11 @@ int gb_interface_activate(struct gb_interface *intf); void gb_interface_deactivate(struct gb_interface *intf); int gb_interface_enable(struct gb_interface *intf); void gb_interface_disable(struct gb_interface *intf); +int gb_interface_timesync_enable(struct gb_interface *intf, u8 count, + u64 frame_time, u32 strobe_delay, u32 refclk); +int gb_interface_timesync_authoritative(struct gb_interface *intf, + u64 *frame_time); +int gb_interface_timesync_disable(struct gb_interface *intf); int gb_interface_add(struct gb_interface *intf); void gb_interface_del(struct gb_interface *intf); void gb_interface_put(struct gb_interface *intf); diff --git a/drivers/staging/greybus/timesync.c b/drivers/staging/greybus/timesync.c new file mode 100644 index 000000000000..260b670596bb --- /dev/null +++ b/drivers/staging/greybus/timesync.c @@ -0,0 +1,1021 @@ +/* + * TimeSync API driver. + * + * Copyright 2016 Google Inc. + * Copyright 2016 Linaro Ltd. + * + * Released under the GPLv2 only. + */ +#include <linux/debugfs.h> +#include "greybus.h" +#include "timesync.h" + +/* + * Minimum inter-strobe value of one millisecond is chosen because it + * just-about fits the common definition of a jiffy. + * + * Maximum value OTOH is constrained by the number of bits the SVC can fit + * into a 16 bit up-counter. The SVC configures the timer in microseconds + * so the maximum allowable value is 65535 microseconds. We clip that value + * to 10000 microseconds for the sake of using nice round base 10 numbers + * and since right-now there's no imaginable use-case requiring anything + * other than a one millisecond inter-strobe time, let alone something + * higher than ten milliseconds. + */ +#define GB_TIMESYNC_STROBE_DELAY_US 1000 +#define GB_TIMESYNC_DEFAULT_OFFSET_US 1000 + +/* Work queue timers long, short and SVC strobe timeout */ +#define GB_TIMESYNC_DELAYED_WORK_LONG msecs_to_jiffies(1000) +#define GB_TIMESYNC_DELAYED_WORK_SHORT msecs_to_jiffies(1) +#define GB_TIMESYNC_MAX_WAIT_SVC msecs_to_jiffies(5000) + +/* Reported nanoseconds per clock */ +static u64 gb_timesync_ns_per_clock; + +/* Reported clock rate */ +static unsigned long gb_timesync_clock_rate; + +/* Workqueue */ +static void gb_timesync_worker(struct work_struct *work); + +/* List of SVCs with one FrameTime per SVC */ +static LIST_HEAD(gb_timesync_svc_list); + +/* Synchronize parallel contexts accessing a valid timesync_svc pointer */ +static DEFINE_MUTEX(gb_timesync_svc_list_mutex); + +struct gb_timesync_svc { + struct list_head list; + struct list_head interface_list; + struct gb_svc *svc; + struct gb_timesync_host_device *timesync_hd; + + spinlock_t spinlock; /* Per SVC spinlock to sync with ISR */ + struct mutex mutex; /* Per SVC mutex for regular synchronization */ + + struct dentry *frame_time_dentry; + struct workqueue_struct *work_queue; + wait_queue_head_t wait_queue; + struct delayed_work delayed_work; + + /* The current local FrameTime */ + u64 frame_time_offset; + u64 strobe_time[GB_TIMESYNC_MAX_STROBES]; + + /* The SVC FrameTime and relative AP FrameTime @ last TIMESYNC_PING */ + u64 svc_ping_frame_time; + u64 ap_ping_frame_time; + + /* Transitory settings */ + u32 strobe_mask; + bool offset_down; + bool print_ping; + bool capture_ping; + int strobe; + + /* Current state */ + int state; +}; + +struct gb_timesync_host_device { + struct list_head list; + struct gb_host_device *hd; + u64 ping_frame_time; +}; + +struct gb_timesync_interface { + struct list_head list; + struct gb_interface *interface; + u64 ping_frame_time; +}; + +enum gb_timesync_state { + GB_TIMESYNC_STATE_INVALID = 0, + GB_TIMESYNC_STATE_INACTIVE = 1, + GB_TIMESYNC_STATE_INIT = 2, + GB_TIMESYNC_STATE_WAIT_SVC = 3, + GB_TIMESYNC_STATE_AUTHORITATIVE = 4, + GB_TIMESYNC_STATE_PING = 5, + GB_TIMESYNC_STATE_ACTIVE = 6, +}; + +static u64 gb_timesync_adjust_count(struct gb_timesync_svc *timesync_svc, + u64 counts) +{ + if (timesync_svc->offset_down) + return counts - timesync_svc->frame_time_offset; + else + return counts + timesync_svc->frame_time_offset; +} + +/* + * This function provides the authoritative FrameTime to a calling function. It + * is designed to be lockless and should remain that way the caller is assumed + * to be state-aware. + */ +static u64 __gb_timesync_get_frame_time(struct gb_timesync_svc *timesync_svc) +{ + u64 clocks = gb_timesync_platform_get_counter(); + + return gb_timesync_adjust_count(timesync_svc, clocks); +} + +static void gb_timesync_schedule_svc_timeout(struct gb_timesync_svc + *timesync_svc) +{ + queue_delayed_work(timesync_svc->work_queue, + ×ync_svc->delayed_work, + GB_TIMESYNC_MAX_WAIT_SVC); +} + +static void gb_timesync_set_state(struct gb_timesync_svc *timesync_svc, + int state) +{ + switch (state) { + case GB_TIMESYNC_STATE_INVALID: + timesync_svc->state = state; + wake_up(×ync_svc->wait_queue); + break; + case GB_TIMESYNC_STATE_INACTIVE: + if (timesync_svc->state != GB_TIMESYNC_STATE_INIT) { + timesync_svc->state = state; + wake_up(×ync_svc->wait_queue); + } + break; + case GB_TIMESYNC_STATE_INIT: + if (timesync_svc->state != GB_TIMESYNC_STATE_INVALID) { + timesync_svc->strobe = 0; + timesync_svc->frame_time_offset = 0; + timesync_svc->state = state; + cancel_delayed_work(×ync_svc->delayed_work); + queue_delayed_work(timesync_svc->work_queue, + ×ync_svc->delayed_work, + GB_TIMESYNC_DELAYED_WORK_LONG); + } + break; + case GB_TIMESYNC_STATE_WAIT_SVC: + if (timesync_svc->state == GB_TIMESYNC_STATE_INIT) + timesync_svc->state = state; + break; + case GB_TIMESYNC_STATE_AUTHORITATIVE: + if (timesync_svc->state == GB_TIMESYNC_STATE_WAIT_SVC) { + timesync_svc->state = state; + cancel_delayed_work(×ync_svc->delayed_work); + queue_delayed_work(timesync_svc->work_queue, + ×ync_svc->delayed_work, 0); + } + break; + case GB_TIMESYNC_STATE_PING: + if (timesync_svc->state == GB_TIMESYNC_STATE_ACTIVE) { + timesync_svc->state = state; + queue_delayed_work(timesync_svc->work_queue, + ×ync_svc->delayed_work, + GB_TIMESYNC_DELAYED_WORK_SHORT); + } + break; + case GB_TIMESYNC_STATE_ACTIVE: + if (timesync_svc->state == GB_TIMESYNC_STATE_AUTHORITATIVE || + timesync_svc->state == GB_TIMESYNC_STATE_PING) { + timesync_svc->state = state; + wake_up(×ync_svc->wait_queue); + } + break; + } + + if (WARN_ON(timesync_svc->state != state)) { + pr_err("Invalid state transition %d=>%d\n", + timesync_svc->state, state); + } +} + +static void gb_timesync_set_state_atomic(struct gb_timesync_svc *timesync_svc, + int state) +{ + unsigned long flags; + + spin_lock_irqsave(×ync_svc->spinlock, flags); + gb_timesync_set_state(timesync_svc, state); + spin_unlock_irqrestore(×ync_svc->spinlock, flags); +} + +static u64 gb_timesync_diff(u64 x, u64 y) +{ + if (x > y) + return x - y; + else + return y - x; +} + +static void gb_timesync_adjust_to_svc(struct gb_timesync_svc *svc, + u64 svc_frame_time, u64 ap_frame_time) +{ + if (svc_frame_time > ap_frame_time) { + svc->frame_time_offset = svc_frame_time - ap_frame_time; + svc->offset_down = false; + } else { + svc->frame_time_offset = ap_frame_time - svc_frame_time; + svc->offset_down = true; + } +} + +/* + * Find the two pulses that best-match our expected inter-strobe gap and + * then calculate the difference between the SVC time at the second pulse + * to the local time at the second pulse. + */ +static void gb_timesync_collate_frame_time(struct gb_timesync_svc *timesync_svc, + u64 *frame_time) +{ + int i = 0; + u64 delta; + u64 strobe_delay_ns = GB_TIMESYNC_STROBE_DELAY_US * NSEC_PER_USEC; + u64 least = 0; + + for (i = 1; i < GB_TIMESYNC_MAX_STROBES; i++) { + delta = timesync_svc->strobe_time[i] - + timesync_svc->strobe_time[i - 1]; + delta *= gb_timesync_ns_per_clock; + delta = gb_timesync_diff(delta, strobe_delay_ns); + + if (!least || delta < least) { + least = delta; + gb_timesync_adjust_to_svc(timesync_svc, frame_time[i], + timesync_svc->strobe_time[i]); + pr_debug("adjust %s local %llu svc %llu delta %llu\n", + timesync_svc->offset_down ? "down" : "up", + timesync_svc->strobe_time[i], frame_time[i], + delta); + } + } +} + +static void gb_timesync_teardown(struct gb_timesync_svc *timesync_svc) +{ + struct gb_timesync_interface *timesync_interface; + struct gb_svc *svc = timesync_svc->svc; + struct gb_interface *interface; + struct gb_host_device *hd; + int ret; + + list_for_each_entry(timesync_interface, + ×ync_svc->interface_list, list) { + interface = timesync_interface->interface; + ret = gb_interface_timesync_disable(interface); + if (ret) { + dev_err(&interface->dev, + "interface timesync_disable %d\n", ret); + } + } + + hd = timesync_svc->timesync_hd->hd; + ret = hd->driver->timesync_disable(hd); + if (ret < 0) { + dev_err(&hd->dev, "host timesync_disable %d\n", + ret); + } + + gb_svc_timesync_wake_pins_release(svc); + gb_svc_timesync_disable(svc); + gb_timesync_platform_unlock_bus(); + + gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_INACTIVE); +} + +static void gb_timesync_platform_lock_bus_fail(struct gb_timesync_svc + *timesync_svc, int ret) +{ + if (ret == -EAGAIN) { + gb_timesync_set_state(timesync_svc, timesync_svc->state); + } else { + pr_err("Failed to lock timesync bus %d\n", ret); + gb_timesync_set_state(timesync_svc, GB_TIMESYNC_STATE_INACTIVE); + } +} + +static void gb_timesync_enable(struct gb_timesync_svc *timesync_svc) +{ + struct gb_svc *svc = timesync_svc->svc; + struct gb_host_device *hd; + struct gb_timesync_interface *timesync_interface; + struct gb_interface *interface; + u64 init_frame_time; + unsigned long clock_rate = gb_timesync_clock_rate; + int ret; + + /* + * Get access to the wake pins in the AP and SVC + * Release these pins either in gb_timesync_teardown() or in + * gb_timesync_authoritative() + */ + ret = gb_timesync_platform_lock_bus(timesync_svc); + if (ret < 0) { + gb_timesync_platform_lock_bus_fail(timesync_svc, ret); + return; + } + ret = gb_svc_timesync_wake_pins_acquire(svc, timesync_svc->strobe_mask); + if (ret) { + dev_err(&svc->dev, + "gb_svc_timesync_wake_pins_acquire %d\n", ret); + gb_timesync_teardown(timesync_svc); + return; + } + + /* Choose an initial time in the future */ + init_frame_time = __gb_timesync_get_frame_time(timesync_svc) + 100000UL; + + /* Send enable command to all relevant participants */ + list_for_each_entry(timesync_interface, ×ync_svc->interface_list, + list) { + interface = timesync_interface->interface; + ret = gb_interface_timesync_enable(interface, + GB_TIMESYNC_MAX_STROBES, + init_frame_time, + GB_TIMESYNC_STROBE_DELAY_US, + clock_rate); + if (ret) { + dev_err(&interface->dev, + "interface timesync_enable %d\n", ret); + } + } + + hd = timesync_svc->timesync_hd->hd; + ret = hd->driver->timesync_enable(hd, GB_TIMESYNC_MAX_STROBES, + init_frame_time, + GB_TIMESYNC_STROBE_DELAY_US, + clock_rate); + if (ret < 0) { + dev_err(&hd->dev, "host timesync_enable %d\n", + ret); + } + + gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_WAIT_SVC); + ret = gb_svc_timesync_enable(svc, GB_TIMESYNC_MAX_STROBES, + init_frame_time, + GB_TIMESYNC_STROBE_DELAY_US, + clock_rate); + if (ret) { + dev_err(&svc->dev, + "gb_svc_timesync_enable %d\n", ret); + gb_timesync_teardown(timesync_svc); + return; + } + + /* Schedule a timeout waiting for SVC to complete strobing */ + gb_timesync_schedule_svc_timeout(timesync_svc); +} + +static void gb_timesync_authoritative(struct gb_timesync_svc *timesync_svc) +{ + struct gb_svc *svc = timesync_svc->svc; + struct gb_host_device *hd; + struct gb_timesync_interface *timesync_interface; + struct gb_interface *interface; + u64 svc_frame_time[GB_TIMESYNC_MAX_STROBES]; + int ret; + + /* Get authoritative time from SVC and adjust local clock */ + ret = gb_svc_timesync_authoritative(svc, svc_frame_time); + if (ret) { + dev_err(&svc->dev, + "gb_svc_timesync_authoritative %d\n", ret); + gb_timesync_teardown(timesync_svc); + return; + } + gb_timesync_collate_frame_time(timesync_svc, svc_frame_time); + + /* Transmit authoritative time to downstream slaves */ + hd = timesync_svc->timesync_hd->hd; + ret = hd->driver->timesync_authoritative(hd, svc_frame_time); + if (ret < 0) + dev_err(&hd->dev, "host timesync_authoritative %d\n", ret); + + list_for_each_entry(timesync_interface, + ×ync_svc->interface_list, list) { + interface = timesync_interface->interface; + ret = gb_interface_timesync_authoritative( + interface, + svc_frame_time); + if (ret) { + dev_err(&interface->dev, + "interface timesync_authoritative %d\n", ret); + } + } + + /* Release wake pins */ + gb_svc_timesync_wake_pins_release(svc); + gb_timesync_platform_unlock_bus(); + + /* Transition to state ACTIVE */ + gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_ACTIVE); + + /* Schedule a ping to verify the synchronized system time */ + timesync_svc->print_ping = true; + gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_PING); +} + +static size_t gb_timesync_log_frame_time(struct gb_timesync_svc *timesync_svc, + char *buf, size_t buflen) +{ + struct gb_svc *svc = timesync_svc->svc; + struct gb_host_device *hd; + struct gb_timesync_interface *timesync_interface; + struct gb_interface *interface; + unsigned int len; + size_t off; + + /* AP/SVC */ + memset(buf, 0x00, buflen); + off = snprintf(buf, buflen, "timesync: ping-time ap=%llu %s=%llu ", + timesync_svc->ap_ping_frame_time, dev_name(&svc->dev), + timesync_svc->svc_ping_frame_time); + len = buflen - off; + + /* APB/GPB */ + if (len < buflen) { + hd = timesync_svc->timesync_hd->hd; + off += snprintf(&buf[off], len, "%s=%llu ", dev_name(&hd->dev), + timesync_svc->timesync_hd->ping_frame_time); + len = buflen - off; + } + + list_for_each_entry(timesync_interface, + ×ync_svc->interface_list, list) { + if (len < buflen) { + interface = timesync_interface->interface; + off += snprintf(&buf[off], len, "%s=%llu ", + dev_name(&interface->dev), + timesync_interface->ping_frame_time); + len = buflen - off; + } + } + if (len < buflen) + off += snprintf(&buf[off], len, "\n"); + return off; +} + +/* + * Send an SVC initiated wake 'ping' to each TimeSync participant. + * Get the FrameTime from each participant associated with the wake + * ping. + */ +static void gb_timesync_ping(struct gb_timesync_svc *timesync_svc) +{ + struct gb_svc *svc = timesync_svc->svc; + struct gb_host_device *hd; + struct gb_timesync_interface *timesync_interface; + struct gb_control *control; + u64 *ping_frame_time; + int ret; + + /* Get access to the wake pins in the AP and SVC */ + ret = gb_timesync_platform_lock_bus(timesync_svc); + if (ret < 0) { + gb_timesync_platform_lock_bus_fail(timesync_svc, ret); + return; + } + ret = gb_svc_timesync_wake_pins_acquire(svc, timesync_svc->strobe_mask); + if (ret) { + dev_err(&svc->dev, + "gb_svc_timesync_wake_pins_acquire %d\n", ret); + gb_timesync_teardown(timesync_svc); + return; + } + + /* Have SVC generate a timesync ping */ + timesync_svc->capture_ping = true; + ret = gb_svc_timesync_ping(svc, ×ync_svc->svc_ping_frame_time); + timesync_svc->capture_ping = false; + if (ret) { + dev_err(&svc->dev, + "gb_svc_timesync_ping %d\n", ret); + gb_timesync_teardown(timesync_svc); + return; + } + + /* Get the ping FrameTime from each APB/GPB */ + hd = timesync_svc->timesync_hd->hd; + ret = hd->driver->timesync_get_last_event(hd, + ×ync_svc->timesync_hd->ping_frame_time); + if (ret) + dev_err(&hd->dev, "host timesync_get_last_event %d\n", ret); + + list_for_each_entry(timesync_interface, + ×ync_svc->interface_list, list) { + control = timesync_interface->interface->control; + ping_frame_time = ×ync_interface->ping_frame_time; + ret = gb_control_timesync_get_last_event(control, + ping_frame_time); + if (ret) { + dev_err(×ync_interface->interface->dev, + "gb_control_timesync_get_last_event %d\n", ret); + } + } + + /* Ping success - move to timesync active */ + gb_svc_timesync_wake_pins_release(svc); + gb_timesync_platform_unlock_bus(); + gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_ACTIVE); +} + +static void gb_timesync_log_ping_time(struct gb_timesync_svc *timesync_svc) +{ + char *buf; + + if (!timesync_svc->print_ping) + return; + + buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (buf) { + gb_timesync_log_frame_time(timesync_svc, buf, PAGE_SIZE); + pr_info("%s", buf); + kfree(buf); + } +} + +/* + * Perform the actual work of scheduled TimeSync logic. + */ +static void gb_timesync_worker(struct work_struct *work) +{ + struct delayed_work *delayed_work = to_delayed_work(work); + struct gb_timesync_svc *timesync_svc = + container_of(delayed_work, struct gb_timesync_svc, delayed_work); + + mutex_lock(×ync_svc->mutex); + + switch (timesync_svc->state) { + case GB_TIMESYNC_STATE_INIT: + gb_timesync_enable(timesync_svc); + break; + + case GB_TIMESYNC_STATE_WAIT_SVC: + dev_err(×ync_svc->svc->dev, + "timeout SVC strobe completion\n"); + gb_timesync_teardown(timesync_svc); + break; + + case GB_TIMESYNC_STATE_AUTHORITATIVE: + gb_timesync_authoritative(timesync_svc); + break; + + case GB_TIMESYNC_STATE_PING: + gb_timesync_ping(timesync_svc); + gb_timesync_log_ping_time(timesync_svc); + break; + + default: + pr_err("Invalid state %d for delayed work\n", + timesync_svc->state); + break; + } + + mutex_unlock(×ync_svc->mutex); +} + +/* + * Schedule a new TimeSync INIT or PING operation serialized w/r to + * gb_timesync_worker(). + */ +static int gb_timesync_schedule(struct gb_timesync_svc *timesync_svc, int state) +{ + int ret = 0; + + if (state != GB_TIMESYNC_STATE_INIT && state != GB_TIMESYNC_STATE_PING) + return -EINVAL; + + mutex_lock(×ync_svc->mutex); + if (timesync_svc->state == GB_TIMESYNC_STATE_INACTIVE || + timesync_svc->state == GB_TIMESYNC_STATE_ACTIVE) { + gb_timesync_set_state_atomic(timesync_svc, state); + } else { + ret = -ENODEV; + } + mutex_unlock(×ync_svc->mutex); + return ret; +} + +static int __gb_timesync_schedule_synchronous( + struct gb_timesync_svc *timesync_svc, int state) +{ + unsigned long flags; + int ret; + + ret = gb_timesync_schedule(timesync_svc, state); + if (ret) + return ret; + + ret = wait_event_interruptible(timesync_svc->wait_queue, + (timesync_svc->state == GB_TIMESYNC_STATE_ACTIVE || + timesync_svc->state == GB_TIMESYNC_STATE_INACTIVE || + timesync_svc->state == GB_TIMESYNC_STATE_INVALID)); + if (ret) + return ret; + + mutex_lock(×ync_svc->mutex); + spin_lock_irqsave(×ync_svc->spinlock, flags); + + switch (timesync_svc->state) { + case GB_TIMESYNC_STATE_INVALID: + case GB_TIMESYNC_STATE_INACTIVE: + ret = -ENODEV; + break; + case GB_TIMESYNC_STATE_INIT: + case GB_TIMESYNC_STATE_WAIT_SVC: + case GB_TIMESYNC_STATE_AUTHORITATIVE: + case GB_TIMESYNC_STATE_PING: + ret = -EAGAIN; + break; + case GB_TIMESYNC_STATE_ACTIVE: + ret = 0; + break; + } + + spin_unlock_irqrestore(×ync_svc->spinlock, flags); + mutex_unlock(×ync_svc->mutex); + + return ret; +} + +static struct gb_timesync_svc *gb_timesync_find_timesync_svc( + struct gb_host_device *hd) +{ + struct gb_timesync_svc *timesync_svc; + + list_for_each_entry(timesync_svc, &gb_timesync_svc_list, list) { + if (timesync_svc->svc == hd->svc) + return timesync_svc; + } + return NULL; +} + +static struct gb_timesync_interface *gb_timesync_find_timesync_interface( + struct gb_timesync_svc *timesync_svc, + struct gb_interface *interface) +{ + struct gb_timesync_interface *timesync_interface; + + list_for_each_entry(timesync_interface, ×ync_svc->interface_list, list) { + if (timesync_interface->interface == interface) + return timesync_interface; + } + return NULL; +} + +int gb_timesync_schedule_synchronous(struct gb_interface *interface) +{ + int ret; + struct gb_timesync_svc *timesync_svc; + + if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC)) + return 0; + + mutex_lock(&gb_timesync_svc_list_mutex); + timesync_svc = gb_timesync_find_timesync_svc(interface->hd); + if (!timesync_svc) { + ret = -ENODEV; + goto done; + } + + ret = __gb_timesync_schedule_synchronous(timesync_svc, + GB_TIMESYNC_STATE_INIT); +done: + mutex_unlock(&gb_timesync_svc_list_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(gb_timesync_schedule_synchronous); + +void gb_timesync_schedule_asynchronous(struct gb_interface *interface) +{ + struct gb_timesync_svc *timesync_svc; + + if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC)) + return; + + mutex_lock(&gb_timesync_svc_list_mutex); + timesync_svc = gb_timesync_find_timesync_svc(interface->hd); + if (!timesync_svc) + goto done; + + gb_timesync_schedule(timesync_svc, GB_TIMESYNC_STATE_INIT); +done: + mutex_unlock(&gb_timesync_svc_list_mutex); + return; +} +EXPORT_SYMBOL_GPL(gb_timesync_schedule_asynchronous); + +static ssize_t gb_timesync_ping_read(struct file *file, char __user *buf, + size_t len, loff_t *offset) +{ + struct gb_timesync_svc *timesync_svc = file->f_inode->i_private; + char *pbuf; + ssize_t ret = 0; + + mutex_lock(&gb_timesync_svc_list_mutex); + mutex_lock(×ync_svc->mutex); + if (list_empty(×ync_svc->interface_list)) + ret = -ENODEV; + timesync_svc->print_ping = false; + mutex_unlock(×ync_svc->mutex); + if (ret) + goto done; + + ret = __gb_timesync_schedule_synchronous(timesync_svc, + GB_TIMESYNC_STATE_PING); + if (ret) + goto done; + + pbuf = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!pbuf) { + ret = -ENOMEM; + goto done; + } + + ret = gb_timesync_log_frame_time(timesync_svc, pbuf, PAGE_SIZE); + if (ret > 0) + ret = simple_read_from_buffer(buf, len, offset, pbuf, ret); + kfree(pbuf); +done: + mutex_unlock(&gb_timesync_svc_list_mutex); + return ret; +} + +static const struct file_operations gb_timesync_debugfs_ops = { + .read = gb_timesync_ping_read, +}; + +static int gb_timesync_hd_add(struct gb_timesync_svc *timesync_svc, + struct gb_host_device *hd) +{ + struct gb_timesync_host_device *timesync_hd; + + timesync_hd = kzalloc(sizeof(*timesync_hd), GFP_KERNEL); + if (!timesync_hd) + return -ENOMEM; + + WARN_ON(timesync_svc->timesync_hd); + timesync_hd->hd = hd; + timesync_svc->timesync_hd = timesync_hd; + + return 0; +} + +static void gb_timesync_hd_remove(struct gb_timesync_svc *timesync_svc, + struct gb_host_device *hd) +{ + if (timesync_svc->timesync_hd->hd == hd) { + kfree(timesync_svc->timesync_hd); + timesync_svc->timesync_hd = NULL; + return; + } + WARN_ON(1); +} + +int gb_timesync_svc_add(struct gb_svc *svc) +{ + struct gb_timesync_svc *timesync_svc; + int ret; + + timesync_svc = kzalloc(sizeof(*timesync_svc), GFP_KERNEL); + if (!timesync_svc) + return -ENOMEM; + + timesync_svc->work_queue = + create_singlethread_workqueue("gb-timesync-work_queue"); + + if (!timesync_svc->work_queue) { + kfree(timesync_svc); + return -ENOMEM; + } + + mutex_lock(&gb_timesync_svc_list_mutex); + INIT_LIST_HEAD(×ync_svc->interface_list); + INIT_DELAYED_WORK(×ync_svc->delayed_work, gb_timesync_worker); + mutex_init(×ync_svc->mutex); + spin_lock_init(×ync_svc->spinlock); + init_waitqueue_head(×ync_svc->wait_queue); + + timesync_svc->svc = svc; + timesync_svc->frame_time_offset = 0; + timesync_svc->capture_ping = false; + gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_INACTIVE); + timesync_svc->frame_time_dentry = + debugfs_create_file("frame-time", S_IRUGO, svc->debugfs_dentry, + timesync_svc, &gb_timesync_debugfs_ops); + list_add(×ync_svc->list, &gb_timesync_svc_list); + ret = gb_timesync_hd_add(timesync_svc, svc->hd); + if (ret) { + list_del(×ync_svc->list); + debugfs_remove(timesync_svc->frame_time_dentry); + destroy_workqueue(timesync_svc->work_queue); + kfree(timesync_svc); + } + mutex_unlock(&gb_timesync_svc_list_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(gb_timesync_svc_add); + +void gb_timesync_svc_remove(struct gb_svc *svc) +{ + struct gb_timesync_svc *timesync_svc; + struct gb_timesync_interface *timesync_interface; + struct gb_timesync_interface *next; + + mutex_lock(&gb_timesync_svc_list_mutex); + timesync_svc = gb_timesync_find_timesync_svc(svc->hd); + if (!timesync_svc) + goto done; + + mutex_lock(×ync_svc->mutex); + + gb_timesync_teardown(timesync_svc); + + gb_timesync_hd_remove(timesync_svc, svc->hd); + list_for_each_entry_safe(timesync_interface, next, + ×ync_svc->interface_list, list) { + list_del(×ync_interface->list); + kfree(timesync_interface); + } + gb_timesync_set_state_atomic(timesync_svc, GB_TIMESYNC_STATE_INVALID); + debugfs_remove(timesync_svc->frame_time_dentry); + cancel_delayed_work_sync(×ync_svc->delayed_work); + destroy_workqueue(timesync_svc->work_queue); + list_del(×ync_svc->list); + + mutex_unlock(×ync_svc->mutex); + + kfree(timesync_svc); +done: + mutex_unlock(&gb_timesync_svc_list_mutex); +} +EXPORT_SYMBOL_GPL(gb_timesync_svc_remove); + +/* + * Add a Greybus Interface to the set of TimeSync Interfaces. + */ +int gb_timesync_interface_add(struct gb_interface *interface) +{ + struct gb_timesync_svc *timesync_svc; + struct gb_timesync_interface *timesync_interface; + int ret = 0; + + if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC)) + return 0; + + mutex_lock(&gb_timesync_svc_list_mutex); + timesync_svc = gb_timesync_find_timesync_svc(interface->hd); + if (!timesync_svc) { + ret = -ENODEV; + goto done; + } + + timesync_interface = kzalloc(sizeof(*timesync_interface), GFP_KERNEL); + if (!timesync_interface) { + ret = -ENOMEM; + goto done; + } + + mutex_lock(×ync_svc->mutex); + timesync_interface->interface = interface; + list_add(×ync_interface->list, ×ync_svc->interface_list); + timesync_svc->strobe_mask |= 1 << interface->interface_id; + mutex_unlock(×ync_svc->mutex); + +done: + mutex_unlock(&gb_timesync_svc_list_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(gb_timesync_interface_add); + +/* + * Remove a Greybus Interface from the set of TimeSync Interfaces. + */ +void gb_timesync_interface_remove(struct gb_interface *interface) +{ + struct gb_timesync_svc *timesync_svc; + struct gb_timesync_interface *timesync_interface; + + if (!(interface->features & GREYBUS_INTERFACE_FEATURE_TIMESYNC)) + return; + + mutex_lock(&gb_timesync_svc_list_mutex); + timesync_svc = gb_timesync_find_timesync_svc(interface->hd); + if (!timesync_svc) + goto done; + + timesync_interface = gb_timesync_find_timesync_interface(timesync_svc, + interface); + if (!timesync_interface) + goto done; + + mutex_lock(×ync_svc->mutex); + timesync_svc->strobe_mask &= ~(1 << interface->interface_id); + list_del(×ync_interface->list); + kfree(timesync_interface); + mutex_unlock(×ync_svc->mutex); +done: + mutex_unlock(&gb_timesync_svc_list_mutex); +} +EXPORT_SYMBOL_GPL(gb_timesync_interface_remove); + +/* + * Give the authoritative FrameTime to the calling function. Returns zero if we + * are not in GB_TIMESYNC_STATE_ACTIVE. + */ +static u64 gb_timesync_get_frame_time(struct gb_timesync_svc *timesync_svc) +{ + unsigned long flags; + u64 ret; + + spin_lock_irqsave(×ync_svc->spinlock, flags); + if (timesync_svc->state == GB_TIMESYNC_STATE_ACTIVE) + ret = __gb_timesync_get_frame_time(timesync_svc); + else + ret = 0; + spin_unlock_irqrestore(×ync_svc->spinlock, flags); + return ret; +} + +u64 gb_timesync_get_frame_time_by_interface(struct gb_interface *interface) +{ + struct gb_timesync_svc *timesync_svc; + u64 ret = 0; + + mutex_lock(&gb_timesync_svc_list_mutex); + timesync_svc = gb_timesync_find_timesync_svc(interface->hd); + if (!timesync_svc) + goto done; + + ret = gb_timesync_get_frame_time(timesync_svc); +done: + mutex_unlock(&gb_timesync_svc_list_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(gb_timesync_get_frame_time_by_interface); + +u64 gb_timesync_get_frame_time_by_svc(struct gb_svc *svc) +{ + struct gb_timesync_svc *timesync_svc; + u64 ret = 0; + + mutex_lock(&gb_timesync_svc_list_mutex); + timesync_svc = gb_timesync_find_timesync_svc(svc->hd); + if (!timesync_svc) + goto done; + + ret = gb_timesync_get_frame_time(timesync_svc); +done: + mutex_unlock(&gb_timesync_svc_list_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(gb_timesync_get_frame_time_by_svc); + +void gb_timesync_irq(struct gb_timesync_svc *timesync_svc) +{ + unsigned long flags; + u64 strobe_time; + + strobe_time = __gb_timesync_get_frame_time(timesync_svc); + + spin_lock_irqsave(×ync_svc->spinlock, flags); + + if (timesync_svc->state == GB_TIMESYNC_STATE_PING) { + if (timesync_svc->capture_ping) + timesync_svc->ap_ping_frame_time = strobe_time; + goto done; + } else if (timesync_svc->state != GB_TIMESYNC_STATE_WAIT_SVC) { + goto done; + } + + timesync_svc->strobe_time[timesync_svc->strobe] = strobe_time; + + if (++timesync_svc->strobe == GB_TIMESYNC_MAX_STROBES) { + gb_timesync_set_state(timesync_svc, + GB_TIMESYNC_STATE_AUTHORITATIVE); + } +done: + spin_unlock_irqrestore(×ync_svc->spinlock, flags); +} +EXPORT_SYMBOL(gb_timesync_irq); + +int __init gb_timesync_init(void) +{ + int ret = 0; + + ret = gb_timesync_platform_init(); + if (ret) { + pr_err("timesync platform init fail!\n"); + return ret; + } + + gb_timesync_clock_rate = gb_timesync_platform_get_clock_rate(); + gb_timesync_ns_per_clock = NSEC_PER_SEC / gb_timesync_clock_rate; + + pr_info("Time-Sync timer frequency %lu Hz\n", gb_timesync_clock_rate); + return 0; +} + +void gb_timesync_exit(void) +{ + gb_timesync_platform_exit(); +} diff --git a/drivers/staging/greybus/timesync.h b/drivers/staging/greybus/timesync.h new file mode 100644 index 000000000000..d907b0feafde --- /dev/null +++ b/drivers/staging/greybus/timesync.h @@ -0,0 +1,41 @@ +/* + * TimeSync API driver. + * + * Copyright 2016 Google Inc. + * Copyright 2016 Linaro Ltd. + * + * Released under the GPLv2 only. + */ + +#ifndef __TIMESYNC_H +#define __TIMESYNC_H + +struct gb_svc; +struct gb_interface; +struct gb_timesync_svc; + +/* Platform */ +u64 gb_timesync_platform_get_counter(void); +u32 gb_timesync_platform_get_clock_rate(void); +int gb_timesync_platform_lock_bus(struct gb_timesync_svc *pdata); +void gb_timesync_platform_unlock_bus(void); + +int gb_timesync_platform_init(void); +void gb_timesync_platform_exit(void); + +/* Core API */ +int gb_timesync_interface_add(struct gb_interface *interface); +void gb_timesync_interface_remove(struct gb_interface *interface); +int gb_timesync_svc_add(struct gb_svc *svc); +void gb_timesync_svc_remove(struct gb_svc *svc); + +u64 gb_timesync_get_frame_time_by_interface(struct gb_interface *interface); +u64 gb_timesync_get_frame_time_by_svc(struct gb_svc *svc); + +int gb_timesync_schedule_synchronous(struct gb_interface *intf); +void gb_timesync_schedule_asynchronous(struct gb_interface *intf); +void gb_timesync_irq(struct gb_timesync_svc *timesync_svc); +int gb_timesync_init(void); +void gb_timesync_exit(void); + +#endif /* __TIMESYNC_H */ diff --git a/drivers/staging/greybus/timesync_platform.c b/drivers/staging/greybus/timesync_platform.c new file mode 100644 index 000000000000..50e8883f932f --- /dev/null +++ b/drivers/staging/greybus/timesync_platform.c @@ -0,0 +1,77 @@ +/* + * TimeSync API driver. + * + * Copyright 2016 Google Inc. + * Copyright 2016 Linaro Ltd. + * + * Released under the GPLv2 only. + * + * This code reads directly from an ARMv7 memory-mapped timer that lives in + * MMIO space. Since this counter lives inside of MMIO space its shared between + * cores and that means we don't have to worry about issues like TSC on x86 + * where each time-stamp-counter (TSC) is local to a particular core. + * + * Register-level access code is based on + * drivers/clocksource/arm_arch_timer.c + */ +#include <linux/cpufreq.h> +#include <linux/of_platform.h> + +#include "greybus.h" +#include "arche_platform.h" + +static u32 gb_timesync_clock_frequency; +int (*arche_platform_change_state_cb)(enum arche_platform_state state, + struct gb_timesync_svc *pdata); +EXPORT_SYMBOL_GPL(arche_platform_change_state_cb); + +u64 gb_timesync_platform_get_counter(void) +{ + return (u64)get_cycles(); +} + +u32 gb_timesync_platform_get_clock_rate(void) +{ + if (unlikely(!gb_timesync_clock_frequency)) + return cpufreq_get(0); + + return gb_timesync_clock_frequency; +} + +int gb_timesync_platform_lock_bus(struct gb_timesync_svc *pdata) +{ + return arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_TIME_SYNC, + pdata); +} + +void gb_timesync_platform_unlock_bus(void) +{ + arche_platform_change_state_cb(ARCHE_PLATFORM_STATE_ACTIVE, NULL); +} + +static const struct of_device_id arch_timer_of_match[] = { + { .compatible = "google,greybus-frame-time-counter", }, + {}, +}; + +int __init gb_timesync_platform_init(void) +{ + struct device_node *np; + + np = of_find_matching_node(NULL, arch_timer_of_match); + if (!np) { + /* Tolerate not finding to allow BBB etc to continue */ + pr_warn("Unable to find a compatible ARMv7 timer\n"); + return 0; + } + + if (of_property_read_u32(np, "clock-frequency", + &gb_timesync_clock_frequency)) { + pr_err("Unable to find timer clock-frequency\n"); + return -ENODEV; + } + + return 0; +} + +void gb_timesync_platform_exit(void) {} |