diff options
Diffstat (limited to 'drivers/gnss')
| -rw-r--r-- | drivers/gnss/sirf.c | 129 |
1 files changed, 102 insertions, 27 deletions
diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c index 49bc021325e9..703d9f17c583 100644 --- a/drivers/gnss/sirf.c +++ b/drivers/gnss/sirf.c @@ -25,6 +25,15 @@ #define SIRF_ON_OFF_PULSE_TIME 100 #define SIRF_ACTIVATE_TIMEOUT 200 #define SIRF_HIBERNATE_TIMEOUT 200 +/* + * If no data arrives for this time, we assume that the chip is off. + * REVISIT: The report cycle is configurable and can be several minutes long, + * so this will only work reliably if the report cycle is set to a reasonable + * low value. Also power saving settings (like send data only on movement) + * might things work even worse. + * Workaround might be to parse shutdown or bootup messages. + */ +#define SIRF_REPORT_CYCLE 2000 struct sirf_data { struct gnss_device *gdev; @@ -39,9 +48,42 @@ struct sirf_data { struct mutex gdev_mutex; bool open; + struct mutex serdev_mutex; + int serdev_count; + wait_queue_head_t power_wait; }; +static int sirf_serdev_open(struct sirf_data *data) +{ + int ret = 0; + + mutex_lock(&data->serdev_mutex); + if (++data->serdev_count == 1) { + ret = serdev_device_open(data->serdev); + if (ret) { + data->serdev_count--; + goto out_unlock; + } + + serdev_device_set_baudrate(data->serdev, data->speed); + serdev_device_set_flow_control(data->serdev, false); + } + +out_unlock: + mutex_unlock(&data->serdev_mutex); + + return ret; +} + +static void sirf_serdev_close(struct sirf_data *data) +{ + mutex_lock(&data->serdev_mutex); + if (--data->serdev_count == 0) + serdev_device_close(data->serdev); + mutex_unlock(&data->serdev_mutex); +} + static int sirf_open(struct gnss_device *gdev) { struct sirf_data *data = gnss_get_drvdata(gdev); @@ -52,7 +94,7 @@ static int sirf_open(struct gnss_device *gdev) data->open = true; mutex_unlock(&data->gdev_mutex); - ret = serdev_device_open(serdev); + ret = sirf_serdev_open(data); if (ret) { mutex_lock(&data->gdev_mutex); data->open = false; @@ -60,10 +102,6 @@ static int sirf_open(struct gnss_device *gdev) return ret; } - - serdev_device_set_baudrate(serdev, data->speed); - serdev_device_set_flow_control(serdev, false); - ret = pm_runtime_get_sync(&serdev->dev); if (ret < 0) { dev_err(&gdev->dev, "failed to runtime resume: %d\n", ret); @@ -74,7 +112,7 @@ static int sirf_open(struct gnss_device *gdev) return 0; err_close: - serdev_device_close(serdev); + sirf_serdev_close(data); mutex_lock(&data->gdev_mutex); data->open = false; @@ -88,7 +126,7 @@ static void sirf_close(struct gnss_device *gdev) struct sirf_data *data = gnss_get_drvdata(gdev); struct serdev_device *serdev = data->serdev; - serdev_device_close(serdev); + sirf_serdev_close(data); pm_runtime_put(&serdev->dev); @@ -128,6 +166,11 @@ static int sirf_receive_buf(struct serdev_device *serdev, struct gnss_device *gdev = data->gdev; int ret = 0; + if (!data->wakeup && !data->active) { + data->active = true; + wake_up_interruptible(&data->power_wait); + } + mutex_lock(&data->gdev_mutex); if (data->open) ret = gnss_insert_raw(gdev, buf, count); @@ -158,11 +201,39 @@ out: return IRQ_HANDLED; } +static int sirf_wait_for_power_state_nowakeup(struct sirf_data *data, + bool active, + unsigned long timeout) +{ + int ret; + + /* Wait for state change (including any shutdown messages). */ + msleep(timeout); + + /* Wait for data reception or timeout. */ + data->active = false; + ret = wait_event_interruptible_timeout(data->power_wait, + data->active, msecs_to_jiffies(SIRF_REPORT_CYCLE)); + if (ret < 0) + return ret; + + if (ret > 0 && !active) + return -ETIMEDOUT; + + if (ret == 0 && active) + return -ETIMEDOUT; + + return 0; +} + static int sirf_wait_for_power_state(struct sirf_data *data, bool active, unsigned long timeout) { int ret; + if (!data->wakeup) + return sirf_wait_for_power_state_nowakeup(data, active, timeout); + ret = wait_event_interruptible_timeout(data->power_wait, data->active == active, msecs_to_jiffies(timeout)); if (ret < 0) @@ -195,21 +266,22 @@ static int sirf_set_active(struct sirf_data *data, bool active) else timeout = SIRF_HIBERNATE_TIMEOUT; + if (!data->wakeup) { + ret = sirf_serdev_open(data); + if (ret) + return ret; + } + do { sirf_pulse_on_off(data); ret = sirf_wait_for_power_state(data, active, timeout); - if (ret < 0) { - if (ret == -ETIMEDOUT) - continue; - - return ret; - } + } while (ret == -ETIMEDOUT && retries--); - break; - } while (retries--); + if (!data->wakeup) + sirf_serdev_close(data); - if (retries < 0) - return -ETIMEDOUT; + if (ret) + return ret; return 0; } @@ -303,6 +375,7 @@ static int sirf_probe(struct serdev_device *serdev) data->gdev = gdev; mutex_init(&data->gdev_mutex); + mutex_init(&data->serdev_mutex); init_waitqueue_head(&data->power_wait); serdev_device_set_drvdata(serdev, data); @@ -329,16 +402,6 @@ static int sirf_probe(struct serdev_device *serdev) if (IS_ERR(data->wakeup)) goto err_put_device; - /* - * Configurations where WAKEUP has been left not connected, - * are currently not supported. - */ - if (!data->wakeup) { - dev_err(dev, "no wakeup gpio specified\n"); - ret = -ENODEV; - goto err_put_device; - } - ret = regulator_enable(data->vcc); if (ret) goto err_put_device; @@ -366,6 +429,17 @@ static int sirf_probe(struct serdev_device *serdev) } if (data->on_off) { + if (!data->wakeup) { + data->active = false; + + ret = sirf_serdev_open(data); + if (ret) + goto err_disable_vcc; + + msleep(SIRF_REPORT_CYCLE); + sirf_serdev_close(data); + } + /* Force hibernate mode if already active. */ if (data->active) { ret = sirf_set_active(data, false); @@ -433,6 +507,7 @@ static void sirf_remove(struct serdev_device *serdev) static const struct of_device_id sirf_of_match[] = { { .compatible = "fastrax,uc430" }, { .compatible = "linx,r4" }, + { .compatible = "wi2wi,w2sg0004" }, { .compatible = "wi2wi,w2sg0008i" }, { .compatible = "wi2wi,w2sg0084i" }, {}, |