diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gnss/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/gnss/Makefile | 3 | ||||
| -rw-r--r-- | drivers/gnss/sirf.c | 407 |
3 files changed, 422 insertions, 0 deletions
diff --git a/drivers/gnss/Kconfig b/drivers/gnss/Kconfig index 784b8c0367d9..6abc88514512 100644 --- a/drivers/gnss/Kconfig +++ b/drivers/gnss/Kconfig @@ -15,6 +15,18 @@ if GNSS config GNSS_SERIAL tristate +config GNSS_SIRF_SERIAL + tristate "SiRFstar GNSS receiver support" + depends on SERIAL_DEV_BUS + ---help--- + Say Y here if you have a SiRFstar-based GNSS receiver which uses a + serial interface. + + To compile this driver as a module, choose M here: the module will + be called gnss-sirf. + + If unsure, say N. + config GNSS_UBX_SERIAL tristate "u-blox GNSS receiver support" depends on SERIAL_DEV_BUS diff --git a/drivers/gnss/Makefile b/drivers/gnss/Makefile index d9295b20b7bc..5cf0ebe0330a 100644 --- a/drivers/gnss/Makefile +++ b/drivers/gnss/Makefile @@ -9,5 +9,8 @@ gnss-y := core.o obj-$(CONFIG_GNSS_SERIAL) += gnss-serial.o gnss-serial-y := serial.o +obj-$(CONFIG_GNSS_SIRF_SERIAL) += gnss-sirf.o +gnss-sirf-y := sirf.o + obj-$(CONFIG_GNSS_UBX_SERIAL) += gnss-ubx.o gnss-ubx-y := ubx.o diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c new file mode 100644 index 000000000000..5fb0f730db48 --- /dev/null +++ b/drivers/gnss/sirf.c @@ -0,0 +1,407 @@ +// 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"); |