[RFC net-next 13/15] net: lora: Prepare RAK RAK811

Andreas Färber
2018-07-01T11:09:04Z

The RAK811 and RAK812 offer a UART based AT command interface.
It allows both LoRaWAN and LoRa modes.

Cc: Ken Yu (禹凯) <ken.yu@rakwireless.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
---
drivers/net/lora/Kconfig | 7 ++
drivers/net/lora/Makefile | 3 +
drivers/net/lora/rak811.c | 219 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 229 insertions(+)
create mode 100644 drivers/net/lora/rak811.c

diff --git a/drivers/net/lora/Kconfig b/drivers/net/lora/Kconfig
index 72a9d2a0f2be..3e384493cbdd 100644
--- a/drivers/net/lora/Kconfig
+++ b/drivers/net/lora/Kconfig
@@ -17,6 +17,13 @@ config LORA_DEV

if LORA_DEV

+config LORA_RAK811
+ tristate "RAK RAK811 driver"
+ default y
+ depends on SERIAL_DEV_BUS
+ help
+ RAK RAK811/RAK812
+
config LORA_RN2483
tristate "Microchip RN2483/RN2903 driver"
default y
diff --git a/drivers/net/lora/Makefile b/drivers/net/lora/Makefile
index dfa9a43dcfb3..6b6870ffbfd8 100644
--- a/drivers/net/lora/Makefile
+++ b/drivers/net/lora/Makefile
@@ -9,6 +9,9 @@ lora-dev-y := dev.o
# Alphabetically sorted.
#

+obj-$(CONFIG_LORA_RAK811) += lora-rak811.o
+lora-rak811-y := rak811.o
+
obj-$(CONFIG_LORA_RN2483) += lora-rn2483.o
lora-rn2483-y := rn2483.o
lora-rn2483-y += rn2483_cmd.o
diff --git a/drivers/net/lora/rak811.c b/drivers/net/lora/rak811.c
new file mode 100644
index 000000000000..ad3d0980c489
--- /dev/null
+++ b/drivers/net/lora/rak811.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RAK RAK811
+ *
+ * Copyright (c) 2017-2018 Andreas Färber
+ */
+
+#include <linux/delay.h>
+#include <linux/lora.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/serdev.h>
+#include <linux/lora/dev.h>
+
+struct rak811_device {
+ struct serdev_device *serdev;
+
+ char rx_buf[4096];
+ int rx_len;
+
+ struct completion line_recv_comp;
+};
+
+static int rak811_send_command(struct rak811_device *rakdev, const char *cmd, char **data, unsigned long timeout)
+{
+ struct serdev_device *sdev = rakdev->serdev;
+ const char *crlf = "\r\n";
+ char *resp;
+
+ serdev_device_write_buf(sdev, cmd, strlen(cmd));
+ serdev_device_write_buf(sdev, crlf, 2);
+
+ timeout = wait_for_completion_timeout(&rakdev->line_recv_comp, timeout);
+ if (!timeout)
+ return -ETIMEDOUT;
+
+ resp = rakdev->rx_buf;
+ dev_dbg(&sdev->dev, "Received: '%s'\n", resp);
+ if (data)
+ *data = kstrdup(resp, GFP_KERNEL);
+
+ rakdev->rx_len = 0;
+ reinit_completion(&rakdev->line_recv_comp);
+
+ return 0;
+}
+
+static int rak811_simple_cmd(struct rak811_device *rakdev, const char *cmd, unsigned long timeout)
+{
+ char *resp;
+ int ret;
+
+ ret = rak811_send_command(rakdev, cmd, &resp, timeout);
+ if (ret)
+ return ret;
+
+ if (strncmp(resp, "OK", 2) == 0) {
+ kfree(resp);
+ return 0;
+ }
+
+ kfree(resp);
+
+ return -EINVAL;
+}
+
+static int rak811_get_version(struct rak811_device *rakdev, char **version, unsigned long timeout)
+{
+ char *resp;
+ int ret;
+
+ ret = rak811_send_command(rakdev, "at+version", &resp, timeout);
+ if (ret)
+ return ret;
+
+ if (strncmp(resp, "OK", 2) == 0) {
+ *version = kstrdup(resp + 2, GFP_KERNEL);
+ kfree(resp);
+ return 0;
+ }
+
+ kfree(resp);
+
+ return -EINVAL;
+}
+
+static int rak811_receive_buf(struct serdev_device *sdev, const u8 *data, size_t count)
+{
+ struct rak811_device *rakdev = serdev_device_get_drvdata(sdev);
+ size_t i = 0;
+ int len = 0;
+
+ dev_dbg(&sdev->dev, "Receive (%d)\n", (int)count);
+
+ for (i = 0; i < count; i++) {
+ dev_dbg(&sdev->dev, "Receive: 0x%02x\n", (int)data[i]);
+ }
+
+ if (completion_done(&rakdev->line_recv_comp)) {
+ dev_info(&sdev->dev, "RX waiting on completion\n");
+ return 0;
+ }
+ if (rakdev->rx_len == sizeof(rakdev->rx_buf) - 1) {
+ dev_warn(&sdev->dev, "RX buffer full\n");
+ return 0;
+ }
+
+ i = min(count, sizeof(rakdev->rx_buf) - 1 - rakdev->rx_len);
+ if (i > 0) {
+ memcpy(&rakdev->rx_buf[rakdev->rx_len], data, i);
+ rakdev->rx_len += i;
+ len += i;
+ }
+ if (rakdev->rx_len >= 2 && strncmp(&rakdev->rx_buf[rakdev->rx_len - 2], "\r\n", 2) == 0) {
+ rakdev->rx_len -= 2;
+ rakdev->rx_buf[rakdev->rx_len] = '\0';
+ complete(&rakdev->line_recv_comp);
+ }
+
+ return len;
+}
+
+static const struct serdev_device_ops rak811_serdev_client_ops = {
+ .receive_buf = rak811_receive_buf,
+};
+
+static int rak811_probe(struct serdev_device *sdev)
+{
+ struct rak811_device *rakdev;
+ char *sz;
+ int ret;
+
+ dev_info(&sdev->dev, "Probing\n");
+
+ rakdev = devm_kzalloc(&sdev->dev, sizeof(struct rak811_device), GFP_KERNEL);
+ if (!rakdev)
+ return -ENOMEM;
+
+ rakdev->serdev = sdev;
+ init_completion(&rakdev->line_recv_comp);
+ serdev_device_set_drvdata(sdev, rakdev);
+
+ ret = serdev_device_open(sdev);
+ if (ret) {
+ dev_err(&sdev->dev, "Failed to open (%d)\n", ret);
+ return ret;
+ }
+
+ serdev_device_set_baudrate(sdev, 115200);
+ serdev_device_set_flow_control(sdev, false);
+ serdev_device_set_client_ops(sdev, &rak811_serdev_client_ops);
+
+ ret = rak811_get_version(rakdev, &sz, HZ);
+ if (ret) {
+ dev_err(&sdev->dev, "Failed to get version (%d)\n", ret);
+ serdev_device_close(sdev);
+ return ret;
+ }
+
+ dev_info(&sdev->dev, "firmware version: %s\n", sz);
+ kfree(sz);
+
+ ret = rak811_simple_cmd(rakdev, "at+mode=1", 2 * HZ);
+ if (ret) {
+ dev_err(&sdev->dev, "Failed to set mode to P2P (%d)\n", ret);
+ serdev_device_close(sdev);
+ return ret;
+ }
+
+ dev_info(&sdev->dev, "Done.\n");
+
+ return 0;
+}
+
+static void rak811_remove(struct serdev_device *sdev)
+{
+ serdev_device_close(sdev);
+
+ dev_info(&sdev->dev, "Removed\n");
+}
+
+static const struct of_device_id rak811_of_match[] = {
+ { .compatible = "rakwireless,rak811" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, rak811_of_match);
+
+static struct serdev_device_driver rak811_serdev_driver = {
+ .probe = rak811_probe,
+ .remove = rak811_remove,
+ .driver = {
+ .name = "rak811",
+ .of_match_table = rak811_of_match,
+ },
+};
+
+static int __init rak811_init(void)
+{
+ int ret;
+
+ ret = serdev_device_driver_register(&rak811_serdev_driver);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void __exit rak811_exit(void)
+{
+ serdev_device_driver_unregister(&rak811_serdev_driver);
+}
+
+module_init(rak811_init);
+module_exit(rak811_exit);
+
+MODULE_DESCRIPTION("RAK811 serdev driver");
+MODULE_AUTHOR("Andreas Färber <afaerber@suse.de>");
+MODULE_LICENSE("GPL");
--
2.16.4