From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/gnss/Kconfig | 68 ++++++ drivers/gnss/Makefile | 22 ++ drivers/gnss/core.c | 420 ++++++++++++++++++++++++++++++++++++ drivers/gnss/mtk.c | 152 +++++++++++++ drivers/gnss/serial.c | 276 ++++++++++++++++++++++++ drivers/gnss/serial.h | 47 ++++ drivers/gnss/sirf.c | 581 ++++++++++++++++++++++++++++++++++++++++++++++++++ drivers/gnss/ubx.c | 153 +++++++++++++ drivers/gnss/usb.c | 214 +++++++++++++++++++ 9 files changed, 1933 insertions(+) create mode 100644 drivers/gnss/Kconfig create mode 100644 drivers/gnss/Makefile create mode 100644 drivers/gnss/core.c create mode 100644 drivers/gnss/mtk.c create mode 100644 drivers/gnss/serial.c create mode 100644 drivers/gnss/serial.h create mode 100644 drivers/gnss/sirf.c create mode 100644 drivers/gnss/ubx.c create mode 100644 drivers/gnss/usb.c (limited to 'drivers/gnss') diff --git a/drivers/gnss/Kconfig b/drivers/gnss/Kconfig new file mode 100644 index 000000000..d7fe265c2 --- /dev/null +++ b/drivers/gnss/Kconfig @@ -0,0 +1,68 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# GNSS receiver configuration +# + +menuconfig GNSS + tristate "GNSS receiver support" + help + Say Y here if you have a GNSS receiver (e.g. a GPS receiver). + + To compile this driver as a module, choose M here: the module will + be called gnss. + +if GNSS + +config GNSS_SERIAL + tristate + +config GNSS_MTK_SERIAL + tristate "Mediatek GNSS receiver support" + depends on SERIAL_DEV_BUS + select GNSS_SERIAL + help + Say Y here if you have a Mediatek-based GNSS receiver which uses a + serial interface. + + To compile this driver as a module, choose M here: the module will + be called gnss-mtk. + + If unsure, say N. + +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 + select GNSS_SERIAL + help + Say Y here if you have a u-blox GNSS receiver which uses a serial + interface. + + To compile this driver as a module, choose M here: the module will + be called gnss-ubx. + + If unsure, say N. + +config GNSS_USB + tristate "USB GNSS receiver support" + depends on USB + help + Say Y here if you have a GNSS receiver which uses a USB interface. + + To compile this driver as a module, choose M here: the module will + be called gnss-usb. + + If unsure, say N. + +endif # GNSS diff --git a/drivers/gnss/Makefile b/drivers/gnss/Makefile new file mode 100644 index 000000000..bb2cbada3 --- /dev/null +++ b/drivers/gnss/Makefile @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the GNSS subsystem. +# + +obj-$(CONFIG_GNSS) += gnss.o +gnss-y := core.o + +obj-$(CONFIG_GNSS_SERIAL) += gnss-serial.o +gnss-serial-y := serial.o + +obj-$(CONFIG_GNSS_MTK_SERIAL) += gnss-mtk.o +gnss-mtk-y := mtk.o + +obj-$(CONFIG_GNSS_SIRF_SERIAL) += gnss-sirf.o +gnss-sirf-y := sirf.o + +obj-$(CONFIG_GNSS_UBX_SERIAL) += gnss-ubx.o +gnss-ubx-y := ubx.o + +obj-$(CONFIG_GNSS_USB) += gnss-usb.o +gnss-usb-y := usb.o diff --git a/drivers/gnss/core.c b/drivers/gnss/core.c new file mode 100644 index 000000000..006f5533e --- /dev/null +++ b/drivers/gnss/core.c @@ -0,0 +1,420 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GNSS receiver core + * + * Copyright (C) 2018 Johan Hovold + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define GNSS_FLAG_HAS_WRITE_RAW BIT(0) + +#define GNSS_MINORS 16 + +static DEFINE_IDA(gnss_minors); +static dev_t gnss_first; + +/* FIFO size must be a power of two */ +#define GNSS_READ_FIFO_SIZE 4096 +#define GNSS_WRITE_BUF_SIZE 1024 + +#define to_gnss_device(d) container_of((d), struct gnss_device, dev) + +static int gnss_open(struct inode *inode, struct file *file) +{ + struct gnss_device *gdev; + int ret = 0; + + gdev = container_of(inode->i_cdev, struct gnss_device, cdev); + + get_device(&gdev->dev); + + stream_open(inode, file); + file->private_data = gdev; + + down_write(&gdev->rwsem); + if (gdev->disconnected) { + ret = -ENODEV; + goto unlock; + } + + if (gdev->count++ == 0) { + ret = gdev->ops->open(gdev); + if (ret) + gdev->count--; + } +unlock: + up_write(&gdev->rwsem); + + if (ret) + put_device(&gdev->dev); + + return ret; +} + +static int gnss_release(struct inode *inode, struct file *file) +{ + struct gnss_device *gdev = file->private_data; + + down_write(&gdev->rwsem); + if (gdev->disconnected) + goto unlock; + + if (--gdev->count == 0) { + gdev->ops->close(gdev); + kfifo_reset(&gdev->read_fifo); + } +unlock: + up_write(&gdev->rwsem); + + put_device(&gdev->dev); + + return 0; +} + +static ssize_t gnss_read(struct file *file, char __user *buf, + size_t count, loff_t *pos) +{ + struct gnss_device *gdev = file->private_data; + unsigned int copied; + int ret; + + mutex_lock(&gdev->read_mutex); + while (kfifo_is_empty(&gdev->read_fifo)) { + mutex_unlock(&gdev->read_mutex); + + if (gdev->disconnected) + return 0; + + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = wait_event_interruptible(gdev->read_queue, + gdev->disconnected || + !kfifo_is_empty(&gdev->read_fifo)); + if (ret) + return -ERESTARTSYS; + + mutex_lock(&gdev->read_mutex); + } + + ret = kfifo_to_user(&gdev->read_fifo, buf, count, &copied); + if (ret == 0) + ret = copied; + + mutex_unlock(&gdev->read_mutex); + + return ret; +} + +static ssize_t gnss_write(struct file *file, const char __user *buf, + size_t count, loff_t *pos) +{ + struct gnss_device *gdev = file->private_data; + size_t written = 0; + int ret; + + if (gdev->disconnected) + return -EIO; + + if (!count) + return 0; + + if (!(gdev->flags & GNSS_FLAG_HAS_WRITE_RAW)) + return -EIO; + + /* Ignoring O_NONBLOCK, write_raw() is synchronous. */ + + ret = mutex_lock_interruptible(&gdev->write_mutex); + if (ret) + return -ERESTARTSYS; + + for (;;) { + size_t n = count - written; + + if (n > GNSS_WRITE_BUF_SIZE) + n = GNSS_WRITE_BUF_SIZE; + + if (copy_from_user(gdev->write_buf, buf, n)) { + ret = -EFAULT; + goto out_unlock; + } + + /* + * Assumes write_raw can always accept GNSS_WRITE_BUF_SIZE + * bytes. + * + * FIXME: revisit + */ + down_read(&gdev->rwsem); + if (!gdev->disconnected) + ret = gdev->ops->write_raw(gdev, gdev->write_buf, n); + else + ret = -EIO; + up_read(&gdev->rwsem); + + if (ret < 0) + break; + + written += ret; + buf += ret; + + if (written == count) + break; + } + + if (written) + ret = written; +out_unlock: + mutex_unlock(&gdev->write_mutex); + + return ret; +} + +static __poll_t gnss_poll(struct file *file, poll_table *wait) +{ + struct gnss_device *gdev = file->private_data; + __poll_t mask = 0; + + poll_wait(file, &gdev->read_queue, wait); + + if (!kfifo_is_empty(&gdev->read_fifo)) + mask |= EPOLLIN | EPOLLRDNORM; + if (gdev->disconnected) + mask |= EPOLLHUP; + + return mask; +} + +static const struct file_operations gnss_fops = { + .owner = THIS_MODULE, + .open = gnss_open, + .release = gnss_release, + .read = gnss_read, + .write = gnss_write, + .poll = gnss_poll, +}; + +static struct class *gnss_class; + +static void gnss_device_release(struct device *dev) +{ + struct gnss_device *gdev = to_gnss_device(dev); + + kfree(gdev->write_buf); + kfifo_free(&gdev->read_fifo); + ida_free(&gnss_minors, gdev->id); + kfree(gdev); +} + +struct gnss_device *gnss_allocate_device(struct device *parent) +{ + struct gnss_device *gdev; + struct device *dev; + int id; + int ret; + + gdev = kzalloc_obj(*gdev); + if (!gdev) + return NULL; + + id = ida_alloc_max(&gnss_minors, GNSS_MINORS - 1, GFP_KERNEL); + if (id < 0) { + kfree(gdev); + return NULL; + } + + gdev->id = id; + + dev = &gdev->dev; + device_initialize(dev); + dev->devt = gnss_first + id; + dev->class = gnss_class; + dev->parent = parent; + dev->release = gnss_device_release; + dev_set_drvdata(dev, gdev); + dev_set_name(dev, "gnss%d", id); + + init_rwsem(&gdev->rwsem); + mutex_init(&gdev->read_mutex); + mutex_init(&gdev->write_mutex); + init_waitqueue_head(&gdev->read_queue); + + ret = kfifo_alloc(&gdev->read_fifo, GNSS_READ_FIFO_SIZE, GFP_KERNEL); + if (ret) + goto err_put_device; + + gdev->write_buf = kzalloc(GNSS_WRITE_BUF_SIZE, GFP_KERNEL); + if (!gdev->write_buf) + goto err_put_device; + + cdev_init(&gdev->cdev, &gnss_fops); + gdev->cdev.owner = THIS_MODULE; + + return gdev; + +err_put_device: + put_device(dev); + + return NULL; +} +EXPORT_SYMBOL_GPL(gnss_allocate_device); + +void gnss_put_device(struct gnss_device *gdev) +{ + put_device(&gdev->dev); +} +EXPORT_SYMBOL_GPL(gnss_put_device); + +int gnss_register_device(struct gnss_device *gdev) +{ + int ret; + + /* Set a flag which can be accessed without holding the rwsem. */ + if (gdev->ops->write_raw != NULL) + gdev->flags |= GNSS_FLAG_HAS_WRITE_RAW; + + ret = cdev_device_add(&gdev->cdev, &gdev->dev); + if (ret) { + dev_err(&gdev->dev, "failed to add device: %d\n", ret); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(gnss_register_device); + +void gnss_deregister_device(struct gnss_device *gdev) +{ + down_write(&gdev->rwsem); + gdev->disconnected = true; + if (gdev->count) { + wake_up_interruptible(&gdev->read_queue); + gdev->ops->close(gdev); + } + up_write(&gdev->rwsem); + + cdev_device_del(&gdev->cdev, &gdev->dev); +} +EXPORT_SYMBOL_GPL(gnss_deregister_device); + +/* + * Caller guarantees serialisation. + * + * Must not be called for a closed device. + */ +int gnss_insert_raw(struct gnss_device *gdev, const unsigned char *buf, + size_t count) +{ + int ret; + + ret = kfifo_in(&gdev->read_fifo, buf, count); + + wake_up_interruptible(&gdev->read_queue); + + return ret; +} +EXPORT_SYMBOL_GPL(gnss_insert_raw); + +static const char * const gnss_type_names[GNSS_TYPE_COUNT] = { + [GNSS_TYPE_NMEA] = "NMEA", + [GNSS_TYPE_SIRF] = "SiRF", + [GNSS_TYPE_UBX] = "UBX", + [GNSS_TYPE_MTK] = "MTK", +}; + +static const char *gnss_type_name(const struct gnss_device *gdev) +{ + const char *name = NULL; + + if (gdev->type < GNSS_TYPE_COUNT) + name = gnss_type_names[gdev->type]; + + if (!name) + dev_WARN(&gdev->dev, "type name not defined\n"); + + return name; +} + +static ssize_t type_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct gnss_device *gdev = to_gnss_device(dev); + + return sprintf(buf, "%s\n", gnss_type_name(gdev)); +} +static DEVICE_ATTR_RO(type); + +static struct attribute *gnss_attrs[] = { + &dev_attr_type.attr, + NULL, +}; +ATTRIBUTE_GROUPS(gnss); + +static int gnss_uevent(const struct device *dev, struct kobj_uevent_env *env) +{ + const struct gnss_device *gdev = to_gnss_device(dev); + int ret; + + ret = add_uevent_var(env, "GNSS_TYPE=%s", gnss_type_name(gdev)); + if (ret) + return ret; + + return 0; +} + +static int __init gnss_module_init(void) +{ + int ret; + + ret = alloc_chrdev_region(&gnss_first, 0, GNSS_MINORS, "gnss"); + if (ret < 0) { + pr_err("failed to allocate device numbers: %d\n", ret); + return ret; + } + + gnss_class = class_create("gnss"); + if (IS_ERR(gnss_class)) { + ret = PTR_ERR(gnss_class); + pr_err("failed to create class: %d\n", ret); + goto err_unregister_chrdev; + } + + gnss_class->dev_groups = gnss_groups; + gnss_class->dev_uevent = gnss_uevent; + + pr_info("GNSS driver registered with major %d\n", MAJOR(gnss_first)); + + return 0; + +err_unregister_chrdev: + unregister_chrdev_region(gnss_first, GNSS_MINORS); + + return ret; +} +module_init(gnss_module_init); + +static void __exit gnss_module_exit(void) +{ + class_destroy(gnss_class); + unregister_chrdev_region(gnss_first, GNSS_MINORS); + ida_destroy(&gnss_minors); +} +module_exit(gnss_module_exit); + +MODULE_AUTHOR("Johan Hovold "); +MODULE_DESCRIPTION("GNSS receiver core"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/gnss/mtk.c b/drivers/gnss/mtk.c new file mode 100644 index 000000000..c62b1211f --- /dev/null +++ b/drivers/gnss/mtk.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Mediatek GNSS receiver driver + * + * Copyright (C) 2018 Johan Hovold + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "serial.h" + +struct mtk_data { + struct regulator *vbackup; + struct regulator *vcc; +}; + +static int mtk_set_active(struct gnss_serial *gserial) +{ + struct mtk_data *data = gnss_serial_get_drvdata(gserial); + int ret; + + ret = regulator_enable(data->vcc); + if (ret) + return ret; + + return 0; +} + +static int mtk_set_standby(struct gnss_serial *gserial) +{ + struct mtk_data *data = gnss_serial_get_drvdata(gserial); + int ret; + + ret = regulator_disable(data->vcc); + if (ret) + return ret; + + return 0; +} + +static int mtk_set_power(struct gnss_serial *gserial, + enum gnss_serial_pm_state state) +{ + switch (state) { + case GNSS_SERIAL_ACTIVE: + return mtk_set_active(gserial); + case GNSS_SERIAL_OFF: + case GNSS_SERIAL_STANDBY: + return mtk_set_standby(gserial); + } + + return -EINVAL; +} + +static const struct gnss_serial_ops mtk_gserial_ops = { + .set_power = mtk_set_power, +}; + +static int mtk_probe(struct serdev_device *serdev) +{ + struct gnss_serial *gserial; + struct mtk_data *data; + int ret; + + gserial = gnss_serial_allocate(serdev, sizeof(*data)); + if (IS_ERR(gserial)) { + ret = PTR_ERR(gserial); + return ret; + } + + gserial->ops = &mtk_gserial_ops; + + gserial->gdev->type = GNSS_TYPE_MTK; + + data = gnss_serial_get_drvdata(gserial); + + data->vcc = devm_regulator_get(&serdev->dev, "vcc"); + if (IS_ERR(data->vcc)) { + ret = PTR_ERR(data->vcc); + goto err_free_gserial; + } + + data->vbackup = devm_regulator_get_optional(&serdev->dev, "vbackup"); + if (IS_ERR(data->vbackup)) { + ret = PTR_ERR(data->vbackup); + if (ret == -ENODEV) + data->vbackup = NULL; + else + goto err_free_gserial; + } + + if (data->vbackup) { + ret = regulator_enable(data->vbackup); + if (ret) + goto err_free_gserial; + } + + ret = gnss_serial_register(gserial); + if (ret) + goto err_disable_vbackup; + + return 0; + +err_disable_vbackup: + if (data->vbackup) + regulator_disable(data->vbackup); +err_free_gserial: + gnss_serial_free(gserial); + + return ret; +} + +static void mtk_remove(struct serdev_device *serdev) +{ + struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); + struct mtk_data *data = gnss_serial_get_drvdata(gserial); + + gnss_serial_deregister(gserial); + if (data->vbackup) + regulator_disable(data->vbackup); + gnss_serial_free(gserial); +} + +#ifdef CONFIG_OF +static const struct of_device_id mtk_of_match[] = { + { .compatible = "globaltop,pa6h" }, + {}, +}; +MODULE_DEVICE_TABLE(of, mtk_of_match); +#endif + +static struct serdev_device_driver mtk_driver = { + .driver = { + .name = "gnss-mtk", + .of_match_table = of_match_ptr(mtk_of_match), + .pm = &gnss_serial_pm_ops, + }, + .probe = mtk_probe, + .remove = mtk_remove, +}; +module_serdev_device_driver(mtk_driver); + +MODULE_AUTHOR("Loys Ollivier "); +MODULE_DESCRIPTION("Mediatek GNSS receiver driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/gnss/serial.c b/drivers/gnss/serial.c new file mode 100644 index 000000000..0e43bf629 --- /dev/null +++ b/drivers/gnss/serial.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generic serial GNSS receiver driver + * + * Copyright (C) 2018 Johan Hovold + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "serial.h" + +static int gnss_serial_open(struct gnss_device *gdev) +{ + struct gnss_serial *gserial = gnss_get_drvdata(gdev); + struct serdev_device *serdev = gserial->serdev; + int ret; + + ret = serdev_device_open(serdev); + if (ret) + return ret; + + serdev_device_set_baudrate(serdev, gserial->speed); + serdev_device_set_flow_control(serdev, false); + + ret = pm_runtime_get_sync(&serdev->dev); + if (ret < 0) { + pm_runtime_put_noidle(&serdev->dev); + goto err_close; + } + + return 0; + +err_close: + serdev_device_close(serdev); + + return ret; +} + +static void gnss_serial_close(struct gnss_device *gdev) +{ + struct gnss_serial *gserial = gnss_get_drvdata(gdev); + struct serdev_device *serdev = gserial->serdev; + + serdev_device_close(serdev); + + pm_runtime_put(&serdev->dev); +} + +static int gnss_serial_write_raw(struct gnss_device *gdev, + const unsigned char *buf, size_t count) +{ + struct gnss_serial *gserial = gnss_get_drvdata(gdev); + struct serdev_device *serdev = gserial->serdev; + int ret; + + /* write is only buffered synchronously */ + ret = serdev_device_write(serdev, buf, count, MAX_SCHEDULE_TIMEOUT); + if (ret < 0 || ret < count) + return ret; + + /* FIXME: determine if interrupted? */ + serdev_device_wait_until_sent(serdev, 0); + + return count; +} + +static const struct gnss_operations gnss_serial_gnss_ops = { + .open = gnss_serial_open, + .close = gnss_serial_close, + .write_raw = gnss_serial_write_raw, +}; + +static size_t gnss_serial_receive_buf(struct serdev_device *serdev, + const u8 *buf, size_t count) +{ + struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); + struct gnss_device *gdev = gserial->gdev; + + return gnss_insert_raw(gdev, buf, count); +} + +static const struct serdev_device_ops gnss_serial_serdev_ops = { + .receive_buf = gnss_serial_receive_buf, + .write_wakeup = serdev_device_write_wakeup, +}; + +static int gnss_serial_set_power(struct gnss_serial *gserial, + enum gnss_serial_pm_state state) +{ + if (!gserial->ops || !gserial->ops->set_power) + return 0; + + return gserial->ops->set_power(gserial, state); +} + +/* + * FIXME: need to provide subdriver defaults or separate dt parsing from + * allocation. + */ +static int gnss_serial_parse_dt(struct serdev_device *serdev) +{ + struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); + struct device_node *node = serdev->dev.of_node; + u32 speed = 4800; + + of_property_read_u32(node, "current-speed", &speed); + + gserial->speed = speed; + + return 0; +} + +struct gnss_serial *gnss_serial_allocate(struct serdev_device *serdev, + size_t data_size) +{ + struct gnss_serial *gserial; + struct gnss_device *gdev; + int ret; + + gserial = kzalloc(sizeof(*gserial) + data_size, GFP_KERNEL); + if (!gserial) + return ERR_PTR(-ENOMEM); + + gdev = gnss_allocate_device(&serdev->dev); + if (!gdev) { + ret = -ENOMEM; + goto err_free_gserial; + } + + gdev->ops = &gnss_serial_gnss_ops; + gnss_set_drvdata(gdev, gserial); + + gserial->serdev = serdev; + gserial->gdev = gdev; + + serdev_device_set_drvdata(serdev, gserial); + serdev_device_set_client_ops(serdev, &gnss_serial_serdev_ops); + + ret = gnss_serial_parse_dt(serdev); + if (ret) + goto err_put_device; + + return gserial; + +err_put_device: + gnss_put_device(gserial->gdev); +err_free_gserial: + kfree(gserial); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(gnss_serial_allocate); + +void gnss_serial_free(struct gnss_serial *gserial) +{ + gnss_put_device(gserial->gdev); + kfree(gserial); +} +EXPORT_SYMBOL_GPL(gnss_serial_free); + +int gnss_serial_register(struct gnss_serial *gserial) +{ + struct serdev_device *serdev = gserial->serdev; + int ret; + + if (IS_ENABLED(CONFIG_PM)) { + pm_runtime_enable(&serdev->dev); + } else { + ret = gnss_serial_set_power(gserial, GNSS_SERIAL_ACTIVE); + if (ret < 0) + return ret; + } + + ret = gnss_register_device(gserial->gdev); + if (ret) + goto err_disable_rpm; + + return 0; + +err_disable_rpm: + if (IS_ENABLED(CONFIG_PM)) + pm_runtime_disable(&serdev->dev); + else + gnss_serial_set_power(gserial, GNSS_SERIAL_OFF); + + return ret; +} +EXPORT_SYMBOL_GPL(gnss_serial_register); + +void gnss_serial_deregister(struct gnss_serial *gserial) +{ + struct serdev_device *serdev = gserial->serdev; + + gnss_deregister_device(gserial->gdev); + + if (IS_ENABLED(CONFIG_PM)) + pm_runtime_disable(&serdev->dev); + else + gnss_serial_set_power(gserial, GNSS_SERIAL_OFF); +} +EXPORT_SYMBOL_GPL(gnss_serial_deregister); + +#ifdef CONFIG_PM +static int gnss_serial_runtime_suspend(struct device *dev) +{ + struct gnss_serial *gserial = dev_get_drvdata(dev); + + return gnss_serial_set_power(gserial, GNSS_SERIAL_STANDBY); +} + +static int gnss_serial_runtime_resume(struct device *dev) +{ + struct gnss_serial *gserial = dev_get_drvdata(dev); + + return gnss_serial_set_power(gserial, GNSS_SERIAL_ACTIVE); +} +#endif /* CONFIG_PM */ + +static int gnss_serial_prepare(struct device *dev) +{ + if (pm_runtime_suspended(dev)) + return 1; + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int gnss_serial_suspend(struct device *dev) +{ + struct gnss_serial *gserial = dev_get_drvdata(dev); + int ret = 0; + + /* + * FIXME: serdev currently lacks support for managing the underlying + * device's wakeup settings. A workaround would be to close the serdev + * device here if it is open. + */ + + if (!pm_runtime_suspended(dev)) + ret = gnss_serial_set_power(gserial, GNSS_SERIAL_STANDBY); + + return ret; +} + +static int gnss_serial_resume(struct device *dev) +{ + struct gnss_serial *gserial = dev_get_drvdata(dev); + int ret = 0; + + if (!pm_runtime_suspended(dev)) + ret = gnss_serial_set_power(gserial, GNSS_SERIAL_ACTIVE); + + return ret; +} +#endif /* CONFIG_PM_SLEEP */ + +const struct dev_pm_ops gnss_serial_pm_ops = { + .prepare = gnss_serial_prepare, + SET_SYSTEM_SLEEP_PM_OPS(gnss_serial_suspend, gnss_serial_resume) + SET_RUNTIME_PM_OPS(gnss_serial_runtime_suspend, gnss_serial_runtime_resume, NULL) +}; +EXPORT_SYMBOL_GPL(gnss_serial_pm_ops); + +MODULE_AUTHOR("Johan Hovold "); +MODULE_DESCRIPTION("Generic serial GNSS receiver driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/gnss/serial.h b/drivers/gnss/serial.h new file mode 100644 index 000000000..621953f78 --- /dev/null +++ b/drivers/gnss/serial.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Generic serial GNSS receiver driver + * + * Copyright (C) 2018 Johan Hovold + */ + +#ifndef _LINUX_GNSS_SERIAL_H +#define _LINUX_GNSS_SERIAL_H + +#include +#include + +struct gnss_serial { + struct serdev_device *serdev; + struct gnss_device *gdev; + speed_t speed; + const struct gnss_serial_ops *ops; + unsigned long drvdata[]; +}; + +enum gnss_serial_pm_state { + GNSS_SERIAL_OFF, + GNSS_SERIAL_ACTIVE, + GNSS_SERIAL_STANDBY, +}; + +struct gnss_serial_ops { + int (*set_power)(struct gnss_serial *gserial, + enum gnss_serial_pm_state state); +}; + +extern const struct dev_pm_ops gnss_serial_pm_ops; + +struct gnss_serial *gnss_serial_allocate(struct serdev_device *gserial, + size_t data_size); +void gnss_serial_free(struct gnss_serial *gserial); + +int gnss_serial_register(struct gnss_serial *gserial); +void gnss_serial_deregister(struct gnss_serial *gserial); + +static inline void *gnss_serial_get_drvdata(struct gnss_serial *gserial) +{ + return gserial->drvdata; +} + +#endif /* _LINUX_GNSS_SERIAL_H */ diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c new file mode 100644 index 000000000..79375d14b --- /dev/null +++ b/drivers/gnss/sirf.c @@ -0,0 +1,581 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SiRFstar GNSS receiver driver + * + * Copyright (C) 2018 Johan Hovold + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SIRF_BOOT_DELAY 500 +#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; + struct serdev_device *serdev; + speed_t speed; + struct regulator *vcc; + struct regulator *lna; + struct gpio_desc *on_off; + struct gpio_desc *wakeup; + int irq; + bool active; + + 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); + struct serdev_device *serdev = data->serdev; + int ret; + + mutex_lock(&data->gdev_mutex); + data->open = true; + mutex_unlock(&data->gdev_mutex); + + ret = sirf_serdev_open(data); + if (ret) { + mutex_lock(&data->gdev_mutex); + data->open = false; + mutex_unlock(&data->gdev_mutex); + return ret; + } + + 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: + sirf_serdev_close(data); + + mutex_lock(&data->gdev_mutex); + data->open = false; + mutex_unlock(&data->gdev_mutex); + + return ret; +} + +static void sirf_close(struct gnss_device *gdev) +{ + struct sirf_data *data = gnss_get_drvdata(gdev); + struct serdev_device *serdev = data->serdev; + + sirf_serdev_close(data); + + pm_runtime_put(&serdev->dev); + + mutex_lock(&data->gdev_mutex); + data->open = false; + mutex_unlock(&data->gdev_mutex); +} + +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, MAX_SCHEDULE_TIMEOUT); + if (ret < 0 || ret < count) + 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 size_t sirf_receive_buf(struct serdev_device *serdev, + const u8 *buf, size_t count) +{ + struct sirf_data *data = serdev_device_get_drvdata(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); + mutex_unlock(&data->gdev_mutex); + + return ret; +} + +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_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) + 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; + + 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); + } while (ret == -ETIMEDOUT && retries--); + + if (!data->wakeup) + sirf_serdev_close(data); + + if (ret) + return ret; + + return 0; +} + +static int sirf_runtime_suspend(struct device *dev) +{ + struct sirf_data *data = dev_get_drvdata(dev); + int ret2; + int ret; + + if (data->on_off) + ret = sirf_set_active(data, false); + else + ret = regulator_disable(data->vcc); + + if (ret) + return ret; + + ret = regulator_disable(data->lna); + if (ret) + goto err_reenable; + + return 0; + +err_reenable: + if (data->on_off) + ret2 = sirf_set_active(data, true); + else + ret2 = regulator_enable(data->vcc); + + if (ret2) + dev_err(dev, + "failed to reenable power on failed suspend: %d\n", + ret2); + + return ret; +} + +static int sirf_runtime_resume(struct device *dev) +{ + struct sirf_data *data = dev_get_drvdata(dev); + int ret; + + ret = regulator_enable(data->lna); + if (ret) + return ret; + + if (data->on_off) + ret = sirf_set_active(data, true); + else + ret = regulator_enable(data->vcc); + + if (ret) + goto err_disable_lna; + + return 0; + +err_disable_lna: + regulator_disable(data->lna); + + return ret; +} + +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->type = GNSS_TYPE_SIRF; + gdev->ops = &sirf_gnss_ops; + gnss_set_drvdata(gdev, data); + + data->serdev = 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); + 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->lna = devm_regulator_get(dev, "lna"); + if (IS_ERR(data->lna)) { + ret = PTR_ERR(data->lna); + goto err_put_device; + } + + data->on_off = devm_gpiod_get_optional(dev, "sirf,onoff", + GPIOD_OUT_LOW); + if (IS_ERR(data->on_off)) { + ret = PTR_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)) { + ret = PTR_ERR(data->wakeup); + goto err_put_device; + } + + ret = regulator_enable(data->vcc); + if (ret) + goto err_put_device; + + /* Wait for chip to boot into hibernate mode. */ + msleep(SIRF_BOOT_DELAY); + } + + if (data->wakeup) { + ret = gpiod_get_value_cansleep(data->wakeup); + if (ret < 0) + goto err_disable_vcc; + data->active = ret; + + ret = gpiod_to_irq(data->wakeup); + if (ret < 0) + goto err_disable_vcc; + data->irq = ret; + + ret = request_threaded_irq(data->irq, NULL, sirf_wakeup_handler, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + "wakeup", data); + if (ret) + goto err_disable_vcc; + } + + 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); + if (ret) { + dev_err(dev, "failed to set hibernate mode: %d\n", + ret); + goto err_free_irq; + } + } + } + + 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_free_irq; + } + + 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_free_irq: + if (data->wakeup) + free_irq(data->irq, data); +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->wakeup) + free_irq(data->irq, data); + + 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,w2sg0004" }, + { .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 "); +MODULE_DESCRIPTION("SiRFstar GNSS receiver driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/gnss/ubx.c b/drivers/gnss/ubx.c new file mode 100644 index 000000000..23894ff75 --- /dev/null +++ b/drivers/gnss/ubx.c @@ -0,0 +1,153 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * u-blox GNSS receiver driver + * + * Copyright (C) 2018 Johan Hovold + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "serial.h" + +struct ubx_data { + struct regulator *vcc; +}; + +static int ubx_set_active(struct gnss_serial *gserial) +{ + struct ubx_data *data = gnss_serial_get_drvdata(gserial); + int ret; + + ret = regulator_enable(data->vcc); + if (ret) + return ret; + + return 0; +} + +static int ubx_set_standby(struct gnss_serial *gserial) +{ + struct ubx_data *data = gnss_serial_get_drvdata(gserial); + int ret; + + ret = regulator_disable(data->vcc); + if (ret) + return ret; + + return 0; +} + +static int ubx_set_power(struct gnss_serial *gserial, + enum gnss_serial_pm_state state) +{ + switch (state) { + case GNSS_SERIAL_ACTIVE: + return ubx_set_active(gserial); + case GNSS_SERIAL_OFF: + case GNSS_SERIAL_STANDBY: + return ubx_set_standby(gserial); + } + + return -EINVAL; +} + +static const struct gnss_serial_ops ubx_gserial_ops = { + .set_power = ubx_set_power, +}; + +static int ubx_probe(struct serdev_device *serdev) +{ + struct gnss_serial *gserial; + struct gpio_desc *safeboot; + struct gpio_desc *reset; + struct ubx_data *data; + int ret; + + gserial = gnss_serial_allocate(serdev, sizeof(*data)); + if (IS_ERR(gserial)) { + ret = PTR_ERR(gserial); + return ret; + } + + gserial->ops = &ubx_gserial_ops; + + gserial->gdev->type = GNSS_TYPE_UBX; + + data = gnss_serial_get_drvdata(gserial); + + data->vcc = devm_regulator_get(&serdev->dev, "vcc"); + if (IS_ERR(data->vcc)) { + ret = PTR_ERR(data->vcc); + goto err_free_gserial; + } + + ret = devm_regulator_get_enable_optional(&serdev->dev, "v-bckp"); + if (ret < 0 && ret != -ENODEV) + goto err_free_gserial; + + /* Deassert safeboot */ + safeboot = devm_gpiod_get_optional(&serdev->dev, "safeboot", GPIOD_OUT_LOW); + if (IS_ERR(safeboot)) { + ret = PTR_ERR(safeboot); + goto err_free_gserial; + } + + /* Deassert reset */ + reset = devm_gpiod_get_optional(&serdev->dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(reset)) { + ret = PTR_ERR(reset); + goto err_free_gserial; + } + + ret = gnss_serial_register(gserial); + if (ret) + goto err_free_gserial; + + return 0; + +err_free_gserial: + gnss_serial_free(gserial); + + return ret; +} + +static void ubx_remove(struct serdev_device *serdev) +{ + struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); + + gnss_serial_deregister(gserial); + gnss_serial_free(gserial); +} + +#ifdef CONFIG_OF +static const struct of_device_id ubx_of_match[] = { + { .compatible = "u-blox,neo-6m" }, + { .compatible = "u-blox,neo-8" }, + { .compatible = "u-blox,neo-m8" }, + {}, +}; +MODULE_DEVICE_TABLE(of, ubx_of_match); +#endif + +static struct serdev_device_driver ubx_driver = { + .driver = { + .name = "gnss-ubx", + .of_match_table = of_match_ptr(ubx_of_match), + .pm = &gnss_serial_pm_ops, + }, + .probe = ubx_probe, + .remove = ubx_remove, +}; +module_serdev_device_driver(ubx_driver); + +MODULE_AUTHOR("Johan Hovold "); +MODULE_DESCRIPTION("u-blox GNSS receiver driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/gnss/usb.c b/drivers/gnss/usb.c new file mode 100644 index 000000000..0d9dde023 --- /dev/null +++ b/drivers/gnss/usb.c @@ -0,0 +1,214 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generic USB GNSS receiver driver + * + * Copyright (C) 2021 Johan Hovold + */ + +#include +#include +#include +#include +#include +#include +#include + +#define GNSS_USB_READ_BUF_LEN 512 +#define GNSS_USB_WRITE_TIMEOUT 1000 + +static const struct usb_device_id gnss_usb_id_table[] = { + { USB_DEVICE(0x1199, 0xb000) }, /* Sierra Wireless XM1210 */ + { } +}; +MODULE_DEVICE_TABLE(usb, gnss_usb_id_table); + +struct gnss_usb { + struct usb_device *udev; + struct usb_interface *intf; + struct gnss_device *gdev; + struct urb *read_urb; + unsigned int write_pipe; +}; + +static void gnss_usb_rx_complete(struct urb *urb) +{ + struct gnss_usb *gusb = urb->context; + struct gnss_device *gdev = gusb->gdev; + int status = urb->status; + int len; + int ret; + + switch (status) { + case 0: + break; + case -ENOENT: + case -ECONNRESET: + case -ESHUTDOWN: + dev_dbg(&gdev->dev, "urb stopped: %d\n", status); + return; + case -EPIPE: + dev_err(&gdev->dev, "urb stopped: %d\n", status); + return; + default: + dev_dbg(&gdev->dev, "nonzero urb status: %d\n", status); + goto resubmit; + } + + len = urb->actual_length; + if (len == 0) + goto resubmit; + + ret = gnss_insert_raw(gdev, urb->transfer_buffer, len); + if (ret < len) + dev_dbg(&gdev->dev, "dropped %d bytes\n", len - ret); +resubmit: + ret = usb_submit_urb(urb, GFP_ATOMIC); + if (ret && ret != -EPERM && ret != -ENODEV) + dev_err(&gdev->dev, "failed to resubmit urb: %d\n", ret); +} + +static int gnss_usb_open(struct gnss_device *gdev) +{ + struct gnss_usb *gusb = gnss_get_drvdata(gdev); + int ret; + + ret = usb_submit_urb(gusb->read_urb, GFP_KERNEL); + if (ret) { + if (ret != -EPERM && ret != -ENODEV) + dev_err(&gdev->dev, "failed to submit urb: %d\n", ret); + return ret; + } + + return 0; +} + +static void gnss_usb_close(struct gnss_device *gdev) +{ + struct gnss_usb *gusb = gnss_get_drvdata(gdev); + + usb_kill_urb(gusb->read_urb); +} + +static int gnss_usb_write_raw(struct gnss_device *gdev, + const unsigned char *buf, size_t count) +{ + struct gnss_usb *gusb = gnss_get_drvdata(gdev); + void *tbuf; + int ret; + + tbuf = kmemdup(buf, count, GFP_KERNEL); + if (!tbuf) + return -ENOMEM; + + ret = usb_bulk_msg(gusb->udev, gusb->write_pipe, tbuf, count, NULL, + GNSS_USB_WRITE_TIMEOUT); + kfree(tbuf); + if (ret) + return ret; + + return count; +} + +static const struct gnss_operations gnss_usb_gnss_ops = { + .open = gnss_usb_open, + .close = gnss_usb_close, + .write_raw = gnss_usb_write_raw, +}; + +static int gnss_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) +{ + struct usb_device *udev = interface_to_usbdev(intf); + struct usb_endpoint_descriptor *in, *out; + struct gnss_device *gdev; + struct gnss_usb *gusb; + struct urb *urb; + size_t buf_len; + void *buf; + int ret; + + ret = usb_find_common_endpoints(intf->cur_altsetting, &in, &out, NULL, + NULL); + if (ret) + return ret; + + gusb = kzalloc_obj(*gusb); + if (!gusb) + return -ENOMEM; + + gdev = gnss_allocate_device(&intf->dev); + if (!gdev) { + ret = -ENOMEM; + goto err_free_gusb; + } + + gdev->ops = &gnss_usb_gnss_ops; + gdev->type = GNSS_TYPE_NMEA; + gnss_set_drvdata(gdev, gusb); + + urb = usb_alloc_urb(0, GFP_KERNEL); + if (!urb) { + ret = -ENOMEM; + goto err_put_gdev; + } + + buf_len = max(usb_endpoint_maxp(in), GNSS_USB_READ_BUF_LEN); + + buf = kzalloc(buf_len, GFP_KERNEL); + if (!buf) { + ret = -ENOMEM; + goto err_free_urb; + } + + usb_fill_bulk_urb(urb, udev, + usb_rcvbulkpipe(udev, usb_endpoint_num(in)), + buf, buf_len, gnss_usb_rx_complete, gusb); + + gusb->intf = intf; + gusb->udev = udev; + gusb->gdev = gdev; + gusb->read_urb = urb; + gusb->write_pipe = usb_sndbulkpipe(udev, usb_endpoint_num(out)); + + ret = gnss_register_device(gdev); + if (ret) + goto err_free_buf; + + usb_set_intfdata(intf, gusb); + + return 0; + +err_free_buf: + kfree(buf); +err_free_urb: + usb_free_urb(urb); +err_put_gdev: + gnss_put_device(gdev); +err_free_gusb: + kfree(gusb); + + return ret; +} + +static void gnss_usb_disconnect(struct usb_interface *intf) +{ + struct gnss_usb *gusb = usb_get_intfdata(intf); + + gnss_deregister_device(gusb->gdev); + + kfree(gusb->read_urb->transfer_buffer); + usb_free_urb(gusb->read_urb); + gnss_put_device(gusb->gdev); + kfree(gusb); +} + +static struct usb_driver gnss_usb_driver = { + .name = "gnss-usb", + .probe = gnss_usb_probe, + .disconnect = gnss_usb_disconnect, + .id_table = gnss_usb_id_table, +}; +module_usb_driver(gnss_usb_driver); + +MODULE_AUTHOR("Johan Hovold "); +MODULE_DESCRIPTION("Generic USB GNSS receiver driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1