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rtc: optee: add alarm related rtc ops to optee rtc driver

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Add read_alarm and set_alarm ops from the rtc framework.
The support of an alarm is handled by a kernel thread waiting in OP-TEE
for an asynchronous notification that comes in the interrupt
handler of the alarm interruption on OP-TEE secure world.

Once the notification arrives, the kernel thread previously suspended
is rescheduled (this is handled by the OP-TEE kernel driver) and comes
back with the alarm information to the kernel.

A second session is therefore needed to enable/disable/cancel a waiting
alarm event as the kernel thread stopped in OP-TEE takes a form of mutex
on the session and so no one can use this session in parallel.

Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Link: https://lore.kernel.org/r/20250715-upstream-optee-rtc-v1-3-e0fdf8aae545@foss.st.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Clément Le Goffic 2025-07-15 16:07:15 +02:00 committed by Alexandre Belloni
parent 44fee00f21
commit 6266aea864
1 changed files with 413 additions and 21 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

426
drivers/rtc/rtc-optee.c
View file

@ -5,19 +5,104 @@
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/tee_drv.h>
#define RTC_INFO_VERSION 0x1
#define TA_CMD_RTC_GET_INFO 0x0
#define TA_CMD_RTC_GET_TIME 0x1
#define TA_CMD_RTC_SET_TIME 0x2
#define TA_CMD_RTC_GET_OFFSET 0x3
#define TA_CMD_RTC_SET_OFFSET 0x4
#define TA_RTC_FEATURE_CORRECTION BIT(0)
#define TA_RTC_FEATURE_ALARM BIT(1)
#define TA_RTC_FEATURE_WAKEUP_ALARM BIT(2)
enum rtc_optee_pta_cmd {
/* PTA_CMD_RTC_GET_INFO - Get RTC information
*
* [out] memref[0] RTC buffer memory reference containing a struct pta_rtc_info
*/
PTA_CMD_RTC_GET_INF = 0x0,
/*
* PTA_CMD_RTC_GET_TIME - Get time from RTC
*
* [out] memref[0] RTC buffer memory reference containing a struct pta_rtc_time
*/
PTA_CMD_RTC_GET_TIME = 0x1,
/*
* PTA_CMD_RTC_SET_TIME - Set time from RTC
*
* [in] memref[0] RTC buffer memory reference containing a struct pta_rtc_time to be
* used as RTC time
*/
PTA_CMD_RTC_SET_TIME = 0x2,
/*
* PTA_CMD_RTC_GET_OFFSET - Get RTC offset
*
* [out] value[0].a RTC offset (signed 32bit value)
*/
PTA_CMD_RTC_GET_OFFSET = 0x3,
/*
* PTA_CMD_RTC_SET_OFFSET - Set RTC offset
*
* [in] value[0].a RTC offset to be set (signed 32bit value)
*/
PTA_CMD_RTC_SET_OFFSET = 0x4,
/*
* PTA_CMD_RTC_READ_ALARM - Read RTC alarm
*
* [out] memref[0] RTC buffer memory reference containing a struct pta_rtc_alarm
*/
PTA_CMD_RTC_READ_ALARM = 0x5,
/*
* PTA_CMD_RTC_SET_ALARM - Set RTC alarm
*
* [in] memref[0] RTC buffer memory reference containing a struct pta_rtc_alarm to be
* used as RTC alarm
*/
PTA_CMD_RTC_SET_ALARM = 0x6,
/*
* PTA_CMD_RTC_ENABLE_ALARM - Enable Alarm
*
* [in] value[0].a RTC IRQ flag (uint32_t), 0 to disable the alarm, 1 to enable
*/
PTA_CMD_RTC_ENABLE_ALARM = 0x7,
/*
* PTA_CMD_RTC_WAIT_ALARM - Get alarm event
*
* [out] value[0].a RTC wait alarm return status (uint32_t):
* - 0: No alarm event
* - 1: Alarm event occurred
* - 2: Alarm event canceled
*/
PTA_CMD_RTC_WAIT_ALARM = 0x8,
/*
* PTA_CMD_RTC_CANCEL_WAIT - Cancel wait for alarm event
*/
PTA_CMD_RTC_CANCEL_WAIT = 0x9,
/*
* PTA_CMD_RTC_SET_WAKE_ALARM_STATUS - Set RTC wake alarm status flag
*
* [in] value[0].a RTC IRQ wake alarm flag (uint32_t), 0 to disable the wake up
* capability, 1 to enable.
*/
PTA_CMD_RTC_SET_WAKE_ALARM_STATUS = 0xA,
};
enum rtc_wait_alarm_status {
WAIT_ALARM_RESET = 0x0,
WAIT_ALARM_ALARM_OCCURRED = 0x1,
WAIT_ALARM_CANCELED = 0x2,
};
struct optee_rtc_time {
u32 tm_sec;
@ -29,6 +114,12 @@ struct optee_rtc_time {
u32 tm_wday;
};
struct optee_rtc_alarm {
u8 enabled;
u8 pending;
struct optee_rtc_time time;
};
struct optee_rtc_info {
u64 version;
u64 features;
@ -41,15 +132,21 @@ struct optee_rtc_info {
* @dev: OP-TEE based RTC device.
* @ctx: OP-TEE context handler.
* @session_id: RTC TA session identifier.
* @session2_id: RTC wait alarm session identifier.
* @shm: Memory pool shared with RTC device.
* @features: Bitfield of RTC features
* @alarm_task: RTC wait alamr task.
* @rtc: RTC device.
*/
struct optee_rtc {
struct device *dev;
struct tee_context *ctx;
u32 session_id;
u32 session2_id;
struct tee_shm *shm;
u64 features;
struct task_struct *alarm_task;
struct rtc_device *rtc;
};
static int optee_rtc_readtime(struct device *dev, struct rtc_time *tm)
@ -60,7 +157,7 @@ static int optee_rtc_readtime(struct device *dev, struct rtc_time *tm)
struct tee_param param[4] = {0};
int ret;
inv_arg.func = TA_CMD_RTC_GET_TIME;
inv_arg.func = PTA_CMD_RTC_GET_TIME;
inv_arg.session = priv->session_id;
inv_arg.num_params = 4;
@ -100,7 +197,7 @@ static int optee_rtc_settime(struct device *dev, struct rtc_time *tm)
struct optee_rtc_time *optee_tm;
int ret;
inv_arg.func = TA_CMD_RTC_SET_TIME;
inv_arg.func = PTA_CMD_RTC_SET_TIME;
inv_arg.session = priv->session_id;
inv_arg.num_params = 4;
@ -137,7 +234,7 @@ static int optee_rtc_readoffset(struct device *dev, long *offset)
if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
return -EOPNOTSUPP;
inv_arg.func = TA_CMD_RTC_GET_OFFSET;
inv_arg.func = PTA_CMD_RTC_GET_OFFSET;
inv_arg.session = priv->session_id;
inv_arg.num_params = 4;
@ -162,7 +259,7 @@ static int optee_rtc_setoffset(struct device *dev, long offset)
if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
return -EOPNOTSUPP;
inv_arg.func = TA_CMD_RTC_SET_OFFSET;
inv_arg.func = PTA_CMD_RTC_SET_OFFSET;
inv_arg.session = priv->session_id;
inv_arg.num_params = 4;
@ -176,13 +273,228 @@ static int optee_rtc_setoffset(struct device *dev, long offset)
return 0;
}
static int optee_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct optee_rtc *priv = dev_get_drvdata(dev);
struct tee_ioctl_invoke_arg inv_arg = {0};
struct optee_rtc_alarm *optee_alarm;
struct tee_param param[1] = {0};
int ret;
if (!(priv->features & TA_RTC_FEATURE_ALARM))
return -EOPNOTSUPP;
inv_arg.func = PTA_CMD_RTC_READ_ALARM;
inv_arg.session = priv->session_id;
inv_arg.num_params = 1;
/* Fill invoke cmd params */
param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
param[0].u.memref.shm = priv->shm;
param[0].u.memref.size = sizeof(struct optee_rtc_alarm);
ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
if (ret < 0 || inv_arg.ret != 0)
return ret ? ret : -EPROTO;
optee_alarm = tee_shm_get_va(priv->shm, 0);
if (IS_ERR(optee_alarm))
return PTR_ERR(alarm);
if (param[0].u.memref.size != sizeof(*optee_alarm))
return -EPROTO;
alarm->enabled = optee_alarm->enabled;
alarm->pending = optee_alarm->pending;
alarm->time.tm_sec = optee_alarm->time.tm_sec;
alarm->time.tm_min = optee_alarm->time.tm_min;
alarm->time.tm_hour = optee_alarm->time.tm_hour;
alarm->time.tm_mday = optee_alarm->time.tm_mday;
alarm->time.tm_mon = optee_alarm->time.tm_mon;
alarm->time.tm_year = optee_alarm->time.tm_year - 1900;
alarm->time.tm_wday = optee_alarm->time.tm_wday;
alarm->time.tm_yday = rtc_year_days(alarm->time.tm_mday,
alarm->time.tm_mon,
alarm->time.tm_year);
return 0;
}
static int optee_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct optee_rtc *priv = dev_get_drvdata(dev);
struct tee_ioctl_invoke_arg inv_arg = {0};
struct optee_rtc_alarm *optee_alarm;
struct tee_param param[1] = {0};
int ret;
if (!(priv->features & TA_RTC_FEATURE_ALARM))
return -EOPNOTSUPP;
inv_arg.func = PTA_CMD_RTC_SET_ALARM;
inv_arg.session = priv->session_id;
inv_arg.num_params = 1;
param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
param[0].u.memref.shm = priv->shm;
param[0].u.memref.size = sizeof(struct optee_rtc_alarm);
optee_alarm = tee_shm_get_va(priv->shm, 0);
if (IS_ERR(optee_alarm))
return PTR_ERR(optee_alarm);
optee_alarm->enabled = alarm->enabled;
optee_alarm->pending = alarm->pending;
optee_alarm->time.tm_sec = alarm->time.tm_sec;
optee_alarm->time.tm_min = alarm->time.tm_min;
optee_alarm->time.tm_hour = alarm->time.tm_hour;
optee_alarm->time.tm_mday = alarm->time.tm_mday;
optee_alarm->time.tm_mon = alarm->time.tm_mon;
optee_alarm->time.tm_year = alarm->time.tm_year + 1900;
optee_alarm->time.tm_wday = alarm->time.tm_wday;
ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
if (ret < 0 || inv_arg.ret != 0)
return ret ? ret : -EPROTO;
return 0;
}
static int optee_rtc_enable_alarm(struct device *dev, unsigned int enabled)
{
struct optee_rtc *priv = dev_get_drvdata(dev);
struct tee_ioctl_invoke_arg inv_arg = {0};
struct tee_param param[1] = {0};
int ret;
if (!(priv->features & TA_RTC_FEATURE_ALARM))
return -EOPNOTSUPP;
inv_arg.func = PTA_CMD_RTC_ENABLE_ALARM;
inv_arg.session = priv->session_id;
inv_arg.num_params = 1;
param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
param[0].u.value.a = (bool)enabled;
ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
if (ret < 0 || inv_arg.ret != 0)
return ret ? ret : -EPROTO;
return 0;
}
static const struct rtc_class_ops optee_rtc_ops = {
.read_time = optee_rtc_readtime,
.set_time = optee_rtc_settime,
.set_offset = optee_rtc_setoffset,
.read_offset = optee_rtc_readoffset,
.read_alarm = optee_rtc_read_alarm,
.set_alarm = optee_rtc_set_alarm,
.alarm_irq_enable = optee_rtc_enable_alarm,
};
static int optee_rtc_wait_alarm(struct device *dev, int *return_status)
{
struct optee_rtc *priv = dev_get_drvdata(dev);
struct tee_ioctl_invoke_arg inv_arg = {0};
struct tee_param param[1] = {0};
int ret;
if (!(priv->features & TA_RTC_FEATURE_ALARM))
return -EOPNOTSUPP;
inv_arg.func = PTA_CMD_RTC_WAIT_ALARM;
inv_arg.session = priv->session2_id;
inv_arg.num_params = 1;
param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
if (ret < 0 || inv_arg.ret != 0)
return ret ? ret : -EPROTO;
*return_status = param[0].u.value.a;
return 0;
}
static int optee_rtc_cancel_wait_alarm(struct device *dev)
{
struct optee_rtc *priv = dev_get_drvdata(dev);
struct tee_ioctl_invoke_arg inv_arg = {0};
struct tee_param param[1] = {0};
int ret;
if (!(priv->features & TA_RTC_FEATURE_ALARM))
return -EOPNOTSUPP;
inv_arg.func = PTA_CMD_RTC_CANCEL_WAIT;
inv_arg.session = priv->session_id;
inv_arg.num_params = 0;
ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
if (ret < 0 || inv_arg.ret != 0)
return ret ? ret : -EPROTO;
return 0;
}
static int optee_rtc_set_alarm_wake_status(struct device *dev, bool status)
{
struct optee_rtc *priv = dev_get_drvdata(dev);
struct tee_ioctl_invoke_arg inv_arg = {0};
struct tee_param param[1] = {0};
int ret;
if (!(priv->features & TA_RTC_FEATURE_ALARM))
return -EOPNOTSUPP;
inv_arg.func = PTA_CMD_RTC_SET_WAKE_ALARM_STATUS;
inv_arg.session = priv->session_id;
inv_arg.num_params = 1;
param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
param[0].u.value.a = status;
ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
if (ret < 0 || inv_arg.ret != 0)
return ret ? ret : -EPROTO;
return 0;
}
static int optee_rtc_handle_alarm_event(void *data)
{
struct optee_rtc *priv = (struct optee_rtc *)data;
int wait_alarm_return_status = 0;
int ret;
while (!kthread_should_stop()) {
ret = optee_rtc_wait_alarm(priv->dev, &wait_alarm_return_status);
if (ret) {
dev_err(priv->dev, "Failed to wait for alarm: %d\n", ret);
return ret;
}
switch (wait_alarm_return_status) {
case WAIT_ALARM_ALARM_OCCURRED:
dev_dbg(priv->dev, "Alarm occurred\n");
rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
break;
case WAIT_ALARM_CANCELED:
dev_dbg(priv->dev, "Alarm canceled\n");
break;
default:
dev_warn(priv->dev, "Unknown return status: %d\n",
wait_alarm_return_status);
break;
}
}
return 0;
}
static int optee_rtc_read_info(struct device *dev, struct rtc_device *rtc,
u64 *features)
{
@ -193,7 +505,7 @@ static int optee_rtc_read_info(struct device *dev, struct rtc_device *rtc,
struct optee_rtc_time *tm;
int ret;
inv_arg.func = TA_CMD_RTC_GET_INFO;
inv_arg.func = PTA_CMD_RTC_GET_INF;
inv_arg.session = priv->session_id;
inv_arg.num_params = 4;
@ -238,6 +550,7 @@ static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
static int optee_rtc_probe(struct device *dev)
{
struct tee_client_device *rtc_device = to_tee_client_device(dev);
struct tee_ioctl_open_session_arg sess2_arg = {0};
struct tee_ioctl_open_session_arg sess_arg = {0};
struct optee_rtc *priv;
struct rtc_device *rtc;
@ -252,12 +565,14 @@ static int optee_rtc_probe(struct device *dev)
if (IS_ERR(rtc))
return PTR_ERR(rtc);
priv->rtc = rtc;
/* Open context with TEE driver */
priv->ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
if (IS_ERR(priv->ctx))
return -ENODEV;
/* Open session with rtc Trusted App */
/* Open first session with rtc Pseudo Trusted App */
export_uuid(sess_arg.uuid, &rtc_device->id.uuid);
sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
@ -269,6 +584,11 @@ static int optee_rtc_probe(struct device *dev)
}
priv->session_id = sess_arg.session;
/*
* Shared memory is used for passing an instance of either struct optee_rtc_info,
* struct optee_rtc_time or struct optee_rtc_alarm to OP-TEE service.
* The former is by definition large enough to cover both parameter cases.
*/
shm = tee_shm_alloc_kernel_buf(priv->ctx, sizeof(struct optee_rtc_info));
if (IS_ERR(shm)) {
dev_err(priv->dev, "tee_shm_alloc_kernel_buf failed\n");
@ -288,19 +608,69 @@ static int optee_rtc_probe(struct device *dev)
goto out_shm;
}
err = devm_rtc_register_device(rtc);
if (err)
/* Handle feature's related setup before registering to rtc framework */
if (priv->features & TA_RTC_FEATURE_ALARM) {
priv->alarm_task = kthread_create(optee_rtc_handle_alarm_event,
priv, "rtc_alarm_evt");
if (IS_ERR(priv->alarm_task)) {
dev_err(dev, "Failed to create alarm thread\n");
goto out_shm;
}
/*
* We must clear this bit after registering because rtc_register_device
* will set it if it sees that .set_offset is provided.
* In case of supported alarm feature on optee side, we create a kthread
* that will, in a new optee session, call a PTA interface "rtc_wait_alarm".
* This call return in case of alarm and in case of canceled alarm.
* The new optee session is therefore only needed in this case as we cannot
* use the same session for parallel calls to optee PTA.
* Hence one session is reserved to wait for alarms and the other to make
* standard calls to RTC PTA.
*/
/* Open second session with rtc Trusted App */
export_uuid(sess2_arg.uuid, &rtc_device->id.uuid);
sess2_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
ret = tee_client_open_session(priv->ctx, &sess2_arg, NULL);
if (ret < 0 || sess2_arg.ret != 0) {
dev_err(dev, "tee_client_open_session failed, err: %x\n", sess2_arg.ret);
err = -EINVAL;
goto out_thrd;
}
priv->session2_id = sess2_arg.session;
if (priv->features & TA_RTC_FEATURE_WAKEUP_ALARM)
device_init_wakeup(dev, true);
}
err = devm_rtc_register_device(rtc);
if (err)
goto out_wk;
/*
* We must clear those bits after registering because registering a rtc_device
* will set them if it sees that .set_offset and .set_alarm are provided.
*/
if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
clear_bit(RTC_FEATURE_CORRECTION, rtc->features);
if (!(priv->features & TA_RTC_FEATURE_ALARM))
clear_bit(RTC_FEATURE_ALARM, rtc->features);
/* Start the thread after the rtc is setup */
if (priv->alarm_task) {
wake_up_process(priv->alarm_task);
dev_dbg(dev, "Wait alarm thread successfully started\n");
}
return 0;
out_wk:
if (priv->features & TA_RTC_FEATURE_ALARM) {
device_init_wakeup(dev, false);
tee_client_close_session(priv->ctx, priv->session2_id);
}
out_thrd:
if (priv->features & TA_RTC_FEATURE_ALARM)
kthread_stop(priv->alarm_task);
out_shm:
tee_shm_free(priv->shm);
out_sess:
@ -315,6 +685,13 @@ static int optee_rtc_remove(struct device *dev)
{
struct optee_rtc *priv = dev_get_drvdata(dev);
if (priv->features & TA_RTC_FEATURE_ALARM) {
optee_rtc_cancel_wait_alarm(dev);
kthread_stop(priv->alarm_task);
device_init_wakeup(dev, false);
tee_client_close_session(priv->ctx, priv->session2_id);
}
tee_shm_free(priv->shm);
tee_client_close_session(priv->ctx, priv->session_id);
tee_client_close_context(priv->ctx);
@ -322,6 +699,20 @@ static int optee_rtc_remove(struct device *dev)
return 0;
}
static int optee_rtc_suspend(struct device *dev)
{
int res = optee_rtc_set_alarm_wake_status(dev, device_may_wakeup(dev));
if (res) {
dev_err(dev, "Unable to transmit wakeup information to optee rtc\n");
return res;
}
return 0;
}
DEFINE_SIMPLE_DEV_PM_OPS(optee_rtc_pm_ops, optee_rtc_suspend, NULL);
static const struct tee_client_device_id optee_rtc_id_table[] = {
{UUID_INIT(0xf389f8c8, 0x845f, 0x496c,
0x8b, 0xbe, 0xd6, 0x4b, 0xd2, 0x4c, 0x92, 0xfd)},
@ -337,6 +728,7 @@ static struct tee_client_driver optee_rtc_driver = {
.bus = &tee_bus_type,
.probe = optee_rtc_probe,
.remove = optee_rtc_remove,
.pm = pm_sleep_ptr(&optee_rtc_pm_ops),
},
};