drivers: modem: Support GSM modems and PPP

Create a driver for GSM modems that use a standard AT command set
and enable Zephyr's own PPP stack for IP traffic.

Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
This commit is contained in:
Patrik Flykt 2020-01-02 12:41:07 +02:00 committed by Jukka Rissanen
commit 2308293d89
4 changed files with 226 additions and 0 deletions

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@ -21,3 +21,8 @@ if(CONFIG_MODEM_WNCM14A2A)
zephyr_library_include_directories(${ZEPHYR_BASE}/subsys/net/ip) zephyr_library_include_directories(${ZEPHYR_BASE}/subsys/net/ip)
zephyr_library_sources(wncm14a2a.c) zephyr_library_sources(wncm14a2a.c)
endif() endif()
if(CONFIG_MODEM_GSM_PPP)
zephyr_library_include_directories(${ZEPHYR_BASE}/subsys/net/ip)
zephyr_library_sources(gsm_ppp.c)
endif()

View file

@ -74,6 +74,7 @@ config MODEM_IFACE_UART
config MODEM_CMD_HANDLER config MODEM_CMD_HANDLER
bool "Generic modem command handler" bool "Generic modem command handler"
select NET_BUF
help help
This generic command handler uses a modem interface to process This generic command handler uses a modem interface to process
incoming data and hand it back to the modem driver via callbacks incoming data and hand it back to the modem driver via callbacks
@ -125,5 +126,6 @@ config MODEM_SHELL
source "drivers/modem/Kconfig.ublox-sara-r4" source "drivers/modem/Kconfig.ublox-sara-r4"
source "drivers/modem/Kconfig.wncm14a2a" source "drivers/modem/Kconfig.wncm14a2a"
source "drivers/modem/Kconfig.gsm"
endif # MODEM endif # MODEM

32
drivers/modem/Kconfig.gsm Normal file
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@ -0,0 +1,32 @@
# Copyright (c) 2020 Intel Corporation
# SPDX-License-Identifier: Apache-2.0
config MODEM_GSM_PPP
bool "Support GSM modems"
select MODEM_CONTEXT
select MODEM_CMD_HANDLER
select MODEM_IFACE_UART
help
Enable GSM modems that support standard AT commands and PPP.
if MODEM_GSM_PPP
config MODEM_GSM_UART_NAME
string "UART device name the modem is connected to"
config MODEM_GSM_INIT_PRIORITY
int "Init priority for the GSM modem driver"
default 42
range 0 99
help
The GSM modem is initialized in POST_KERNEL using priority in
the range 0-99.
config MODEM_GSM_APN
string "Access Point Name"
default "internet"
help
Specify Access Point Name, i.e. the name to identify Internet IP
GPRS cellular data context.
endif

187
drivers/modem/gsm_ppp.c Normal file
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@ -0,0 +1,187 @@
/*
* Copyright (c) 2020 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <logging/log.h>
LOG_MODULE_REGISTER(gsm_ppp, CONFIG_NET_PPP_LOG_LEVEL);
#include <kernel.h>
#include <device.h>
#include <sys/ring_buffer.h>
#include <sys/util.h>
#include <net/ppp.h>
#include "modem_context.h"
#include "modem_iface_uart.h"
#include "modem_cmd_handler.h"
#define GSM_CMD_READ_BUF 128
#define GSM_CMD_AT_TIMEOUT K_SECONDS(2)
#define GSM_CMD_SETUP_TIMEOUT K_SECONDS(6)
#define GSM_RX_STACK_SIZE 1024
#define GSM_RECV_MAX_BUF 30
#define GSM_RECV_BUF_SIZE 128
static struct gsm_modem {
struct modem_context context;
struct modem_cmd_handler_data cmd_handler_data;
u8_t cmd_read_buf[GSM_CMD_READ_BUF];
u8_t cmd_match_buf[GSM_CMD_READ_BUF];
struct k_sem sem_response;
struct modem_iface_uart_data gsm_data;
struct k_delayed_work gsm_configure_work;
char gsm_isr_buf[PPP_MRU];
char gsm_rx_rb_buf[PPP_MRU * 3];
} gsm;
NET_BUF_POOL_DEFINE(gsm_recv_pool, GSM_RECV_MAX_BUF, GSM_RECV_BUF_SIZE,
0, NULL);
K_THREAD_STACK_DEFINE(gsm_rx_stack, GSM_RX_STACK_SIZE);
struct k_thread gsm_rx_thread;
static void gsm_rx(void)
{
LOG_DBG("starting");
while (true) {
k_sem_take(&gsm.gsm_data.rx_sem, K_FOREVER);
gsm.context.cmd_handler.process(&gsm.context.cmd_handler,
&gsm.context.iface);
k_yield();
}
}
MODEM_CMD_DEFINE(gsm_cmd_ok)
{
modem_cmd_handler_set_error(data, 0);
LOG_DBG("ok");
k_sem_give(&gsm.sem_response);
}
MODEM_CMD_DEFINE(gsm_cmd_error)
{
modem_cmd_handler_set_error(data, -EINVAL);
LOG_DBG("error");
k_sem_give(&gsm.sem_response);
}
static struct modem_cmd response_cmds[] = {
MODEM_CMD("OK", gsm_cmd_ok, 0U, ""),
MODEM_CMD("ERROR", gsm_cmd_error, 0U, ""),
MODEM_CMD("CONNECT", gsm_cmd_ok, 0U, ""),
};
static struct setup_cmd setup_cmds[] = {
/* no echo */
SETUP_CMD_NOHANDLE("ATE0"),
/* hang up */
SETUP_CMD_NOHANDLE("ATH"),
/* extender errors in numeric form */
SETUP_CMD_NOHANDLE("AT+CMEE=1"),
/* disable unsolicited network registration codes */
SETUP_CMD_NOHANDLE("AT+CREG=0"),
/* create PDP context */
SETUP_CMD_NOHANDLE("AT+CGDCONT=1,\"IP\",\"" CONFIG_MODEM_GSM_APN "\""),
/* connect to network */
SETUP_CMD_NOHANDLE("ATD*99#")
};
static void gsm_configure(struct k_work *work)
{
int r = -1;
struct gsm_modem *gsm = CONTAINER_OF(work, struct gsm_modem,
gsm_configure_work);
LOG_DBG("Starting modem %p configuration", gsm);
while (r < 0) {
while (true) {
r = modem_cmd_send(&gsm->context.iface,
&gsm->context.cmd_handler,
&response_cmds[0],
ARRAY_SIZE(response_cmds),
"AT", &gsm->sem_response,
GSM_CMD_AT_TIMEOUT);
if (r < 0) {
LOG_DBG("modem not ready %d", r);
} else {
LOG_DBG("connect with modem %d", r);
break;
}
}
r = modem_cmd_handler_setup_cmds(&gsm->context.iface,
&gsm->context.cmd_handler,
setup_cmds,
ARRAY_SIZE(setup_cmds),
&gsm->sem_response,
GSM_CMD_SETUP_TIMEOUT);
if (r < 0) {
LOG_DBG("modem setup returned %d, %s",
r, "retrying...");
}
}
}
int gsm_init(struct device *device)
{
int r;
LOG_DBG("");
gsm.cmd_handler_data.cmds[CMD_RESP] = response_cmds;
gsm.cmd_handler_data.cmds_len[CMD_RESP] = ARRAY_SIZE(response_cmds);
gsm.cmd_handler_data.read_buf = &gsm.cmd_read_buf[0];
gsm.cmd_handler_data.read_buf_len = sizeof(gsm.cmd_read_buf);
gsm.cmd_handler_data.match_buf = &gsm.cmd_match_buf[0];
gsm.cmd_handler_data.match_buf_len = sizeof(gsm.cmd_match_buf);
gsm.cmd_handler_data.buf_pool = &gsm_recv_pool;
k_sem_init(&gsm.sem_response, 0, 1);
r = modem_cmd_handler_init(&gsm.context.cmd_handler,
&gsm.cmd_handler_data);
if (r < 0) {
LOG_DBG("cmd handler error %d", r);
return r;
}
gsm.gsm_data.isr_buf = &gsm.gsm_isr_buf[0];
gsm.gsm_data.isr_buf_len = sizeof(gsm.gsm_isr_buf);
gsm.gsm_data.rx_rb_buf = &gsm.gsm_rx_rb_buf[0];
gsm.gsm_data.rx_rb_buf_len = sizeof(gsm.gsm_rx_rb_buf);
r = modem_iface_uart_init(&gsm.context.iface,
&gsm.gsm_data, CONFIG_MODEM_GSM_UART_NAME);
if (r < 0) {
LOG_DBG("iface uart error %d", r);
return r;
}
r = modem_context_register(&gsm.context);
if (r < 0) {
LOG_DBG("context error %d", r);
return r;
}
k_thread_create(&gsm_rx_thread, gsm_rx_stack,
K_THREAD_STACK_SIZEOF(gsm_rx_stack),
(k_thread_entry_t) gsm_rx,
NULL, NULL, NULL, K_PRIO_COOP(7), 0, K_NO_WAIT);
k_delayed_work_init(&gsm.gsm_configure_work, gsm_configure);
(void)k_delayed_work_submit(&gsm.gsm_configure_work, 0);
LOG_DBG("iface->read %p iface->write %p",
gsm.context.iface.read, gsm.context.iface.write);
return 0;
}
DEVICE_INIT(gsm_ppp, "modem_gsm", gsm_init, NULL, NULL, POST_KERNEL,
CONFIG_MODEM_GSM_INIT_PRIORITY);