--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SiRFstar GNSS receiver driver
+ *
+ * Copyright (C) 2018 Johan Hovold <johan@kernel.org>
+ */
+
+#include <linux/errno.h>
+#include <linux/gnss.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+#include <linux/serdev.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#define SIRF_BOOT_DELAY 500
+#define SIRF_ON_OFF_PULSE_TIME 100
+#define SIRF_ACTIVATE_TIMEOUT 200
+#define SIRF_HIBERNATE_TIMEOUT 200
+
+struct sirf_data {
+ struct gnss_device *gdev;
+ struct serdev_device *serdev;
+ speed_t speed;
+ struct regulator *vcc;
+ struct gpio_desc *on_off;
+ struct gpio_desc *wakeup;
+ int irq;
+ bool active;
+ wait_queue_head_t power_wait;
+};
+
+static int sirf_open(struct gnss_device *gdev)
+{
+ struct sirf_data *data = gnss_get_drvdata(gdev);
+ struct serdev_device *serdev = data->serdev;
+ int ret;
+
+ ret = serdev_device_open(serdev);
+ if (ret)
+ 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);
+ pm_runtime_put_noidle(&serdev->dev);
+ goto err_close;
+ }
+
+ return 0;
+
+err_close:
+ serdev_device_close(serdev);
+
+ return ret;
+}
+
+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);
+
+ pm_runtime_put(&serdev->dev);
+}
+
+static int sirf_write_raw(struct gnss_device *gdev, const unsigned char *buf,
+ size_t count)
+{
+ struct sirf_data *data = gnss_get_drvdata(gdev);
+ struct serdev_device *serdev = data->serdev;
+ int ret;
+
+ /* write is only buffered synchronously */
+ ret = serdev_device_write(serdev, buf, count, 0);
+ if (ret < 0)
+ return ret;
+
+ /* FIXME: determine if interrupted? */
+ serdev_device_wait_until_sent(serdev, 0);
+
+ return count;
+}
+
+static const struct gnss_operations sirf_gnss_ops = {
+ .open = sirf_open,
+ .close = sirf_close,
+ .write_raw = sirf_write_raw,
+};
+
+static int sirf_receive_buf(struct serdev_device *serdev,
+ const unsigned char *buf, size_t count)
+{
+ struct sirf_data *data = serdev_device_get_drvdata(serdev);
+ struct gnss_device *gdev = data->gdev;
+
+ return gnss_insert_raw(gdev, buf, count);
+}
+
+static const struct serdev_device_ops sirf_serdev_ops = {
+ .receive_buf = sirf_receive_buf,
+ .write_wakeup = serdev_device_write_wakeup,
+};
+
+static irqreturn_t sirf_wakeup_handler(int irq, void *dev_id)
+{
+ struct sirf_data *data = dev_id;
+ struct device *dev = &data->serdev->dev;
+ int ret;
+
+ ret = gpiod_get_value_cansleep(data->wakeup);
+ dev_dbg(dev, "%s - wakeup = %d\n", __func__, ret);
+ if (ret < 0)
+ goto out;
+
+ data->active = !!ret;
+ wake_up_interruptible(&data->power_wait);
+out:
+ return IRQ_HANDLED;
+}
+
+static int sirf_wait_for_power_state(struct sirf_data *data, bool active,
+ unsigned long timeout)
+{
+ int ret;
+
+ ret = wait_event_interruptible_timeout(data->power_wait,
+ data->active == active, msecs_to_jiffies(timeout));
+ if (ret < 0)
+ return ret;
+
+ if (ret == 0) {
+ dev_warn(&data->serdev->dev, "timeout waiting for active state = %d\n",
+ active);
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static void sirf_pulse_on_off(struct sirf_data *data)
+{
+ gpiod_set_value_cansleep(data->on_off, 1);
+ msleep(SIRF_ON_OFF_PULSE_TIME);
+ gpiod_set_value_cansleep(data->on_off, 0);
+}
+
+static int sirf_set_active(struct sirf_data *data, bool active)
+{
+ unsigned long timeout;
+ int retries = 3;
+ int ret;
+
+ if (active)
+ timeout = SIRF_ACTIVATE_TIMEOUT;
+ else
+ timeout = SIRF_HIBERNATE_TIMEOUT;
+
+ while (retries-- > 0) {
+ sirf_pulse_on_off(data);
+ ret = sirf_wait_for_power_state(data, active, timeout);
+ if (ret < 0) {
+ if (ret == -ETIMEDOUT)
+ continue;
+
+ return ret;
+ }
+
+ break;
+ }
+
+ if (retries == 0)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int sirf_runtime_suspend(struct device *dev)
+{
+ struct sirf_data *data = dev_get_drvdata(dev);
+
+ if (!data->on_off)
+ return regulator_disable(data->vcc);
+
+ return sirf_set_active(data, false);
+}
+
+static int sirf_runtime_resume(struct device *dev)
+{
+ struct sirf_data *data = dev_get_drvdata(dev);
+
+ if (!data->on_off)
+ return regulator_enable(data->vcc);
+
+ return sirf_set_active(data, true);
+}
+
+static int __maybe_unused sirf_suspend(struct device *dev)
+{
+ struct sirf_data *data = dev_get_drvdata(dev);
+ int ret = 0;
+
+ if (!pm_runtime_suspended(dev))
+ ret = sirf_runtime_suspend(dev);
+
+ if (data->wakeup)
+ disable_irq(data->irq);
+
+ return ret;
+}
+
+static int __maybe_unused sirf_resume(struct device *dev)
+{
+ struct sirf_data *data = dev_get_drvdata(dev);
+ int ret = 0;
+
+ if (data->wakeup)
+ enable_irq(data->irq);
+
+ if (!pm_runtime_suspended(dev))
+ ret = sirf_runtime_resume(dev);
+
+ return ret;
+}
+
+static const struct dev_pm_ops sirf_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(sirf_suspend, sirf_resume)
+ SET_RUNTIME_PM_OPS(sirf_runtime_suspend, sirf_runtime_resume, NULL)
+};
+
+static int sirf_parse_dt(struct serdev_device *serdev)
+{
+ struct sirf_data *data = serdev_device_get_drvdata(serdev);
+ struct device_node *node = serdev->dev.of_node;
+ u32 speed = 9600;
+
+ of_property_read_u32(node, "current-speed", &speed);
+
+ data->speed = speed;
+
+ return 0;
+}
+
+static int sirf_probe(struct serdev_device *serdev)
+{
+ struct device *dev = &serdev->dev;
+ struct gnss_device *gdev;
+ struct sirf_data *data;
+ int ret;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ gdev = gnss_allocate_device(dev);
+ if (!gdev)
+ return -ENOMEM;
+
+ gdev->ops = &sirf_gnss_ops;
+ gnss_set_drvdata(gdev, data);
+
+ data->serdev = serdev;
+ data->gdev = gdev;
+
+ init_waitqueue_head(&data->power_wait);
+
+ serdev_device_set_drvdata(serdev, data);
+ serdev_device_set_client_ops(serdev, &sirf_serdev_ops);
+
+ ret = sirf_parse_dt(serdev);
+ if (ret)
+ goto err_put_device;
+
+ data->vcc = devm_regulator_get(dev, "vcc");
+ if (IS_ERR(data->vcc)) {
+ ret = PTR_ERR(data->vcc);
+ goto err_put_device;
+ }
+
+ data->on_off = devm_gpiod_get_optional(dev, "sirf,onoff",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(data->on_off))
+ goto err_put_device;
+
+ if (data->on_off) {
+ data->wakeup = devm_gpiod_get_optional(dev, "sirf,wakeup",
+ GPIOD_IN);
+ 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;
+ }
+ }
+
+ if (data->wakeup) {
+ ret = gpiod_to_irq(data->wakeup);
+ if (ret < 0)
+ goto err_put_device;
+
+ data->irq = ret;
+
+ ret = devm_request_threaded_irq(dev, data->irq, NULL,
+ sirf_wakeup_handler,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ "wakeup", data);
+ if (ret)
+ goto err_put_device;
+ }
+
+ if (data->on_off) {
+ ret = regulator_enable(data->vcc);
+ if (ret)
+ goto err_put_device;
+
+ /* Wait for chip to boot into hibernate mode */
+ msleep(SIRF_BOOT_DELAY);
+ }
+
+ if (IS_ENABLED(CONFIG_PM)) {
+ pm_runtime_set_suspended(dev); /* clear runtime_error flag */
+ pm_runtime_enable(dev);
+ } else {
+ ret = sirf_runtime_resume(dev);
+ if (ret < 0)
+ goto err_disable_vcc;
+ }
+
+ ret = gnss_register_device(gdev);
+ if (ret)
+ goto err_disable_rpm;
+
+ return 0;
+
+err_disable_rpm:
+ if (IS_ENABLED(CONFIG_PM))
+ pm_runtime_disable(dev);
+ else
+ sirf_runtime_suspend(dev);
+err_disable_vcc:
+ if (data->on_off)
+ regulator_disable(data->vcc);
+err_put_device:
+ gnss_put_device(data->gdev);
+
+ return ret;
+}
+
+static void sirf_remove(struct serdev_device *serdev)
+{
+ struct sirf_data *data = serdev_device_get_drvdata(serdev);
+
+ gnss_deregister_device(data->gdev);
+
+ if (IS_ENABLED(CONFIG_PM))
+ pm_runtime_disable(&serdev->dev);
+ else
+ sirf_runtime_suspend(&serdev->dev);
+
+ if (data->on_off)
+ regulator_disable(data->vcc);
+
+ gnss_put_device(data->gdev);
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id sirf_of_match[] = {
+ { .compatible = "fastrax,uc430" },
+ { .compatible = "linx,r4" },
+ { .compatible = "wi2wi,w2sg0008i" },
+ { .compatible = "wi2wi,w2sg0084i" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sirf_of_match);
+#endif
+
+static struct serdev_device_driver sirf_driver = {
+ .driver = {
+ .name = "gnss-sirf",
+ .of_match_table = of_match_ptr(sirf_of_match),
+ .pm = &sirf_pm_ops,
+ },
+ .probe = sirf_probe,
+ .remove = sirf_remove,
+};
+module_serdev_device_driver(sirf_driver);
+
+MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
+MODULE_DESCRIPTION("SiRFstar GNSS receiver driver");
+MODULE_LICENSE("GPL v2");
projects / users / jedix / linux-maple.git / commitdiff