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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-18 21:04:51 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-18 21:04:51 +0300
commitd5acba26bfa097a618be425522b1ec4269d3edaf (patch)
tree7abb08032d4b79b34eb1386aa007a811e1964839 /drivers/gnss/serial.c
parent2475c515d4031c494ff452508a8bf8c281ec6e56 (diff)
parent128f38041035001276e964cda1cf951f218d965d (diff)
downloadlinux-d5acba26bfa097a618be425522b1ec4269d3edaf.tar.xz
Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH: "Here is the bit set of char/misc drivers for 4.19-rc1 There is a lot here, much more than normal, seems like everyone is writing new driver subsystems these days... Anyway, major things here are: - new FSI driver subsystem, yet-another-powerpc low-level hardware bus - gnss, finally an in-kernel GPS subsystem to try to tame all of the crazy out-of-tree drivers that have been floating around for years, combined with some really hacky userspace implementations. This is only for GNSS receivers, but you have to start somewhere, and this is great to see. Other than that, there are new slimbus drivers, new coresight drivers, new fpga drivers, and loads of DT bindings for all of these and existing drivers. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits) android: binder: Rate-limit debug and userspace triggered err msgs fsi: sbefifo: Bump max command length fsi: scom: Fix NULL dereference misc: mic: SCIF Fix scif_get_new_port() error handling misc: cxl: changed asterisk position genwqe: card_base: Use true and false for boolean values misc: eeprom: assignment outside the if statement uio: potential double frees if __uio_register_device() fails eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency misc: ti-st: Fix memory leak in the error path of probe() android: binder: Show extra_buffers_size in trace firmware: vpd: Fix section enabled flag on vpd_section_destroy platform: goldfish: Retire pdev_bus goldfish: Use dedicated macros instead of manual bit shifting goldfish: Add missing includes to goldfish.h mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux dt-bindings: mux: add adi,adgs1408 Drivers: hv: vmbus: Cleanup synic memory free path Drivers: hv: vmbus: Remove use of slow_virt_to_phys() Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind() ...
Diffstat (limited to 'drivers/gnss/serial.c')
-rw-r--r--drivers/gnss/serial.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/gnss/serial.c b/drivers/gnss/serial.c
new file mode 100644
index 000000000000..b01ba4438501
--- /dev/null
+++ b/drivers/gnss/serial.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic serial GNSS receiver driver
+ *
+ * Copyright (C) 2018 Johan Hovold <johan@kernel.org>
+ */
+
+#include <linux/errno.h>
+#include <linux/gnss.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/serdev.h>
+#include <linux/slab.h>
+
+#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, 0);
+ if (ret < 0)
+ 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 int gnss_serial_receive_buf(struct serdev_device *serdev,
+ const unsigned char *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 <johan@kernel.org>");
+MODULE_DESCRIPTION("Generic serial GNSS receiver driver");
+MODULE_LICENSE("GPL v2");