linux-stable/drivers/rtc/rtc-imx-sc.c
Bartosz Golaszewski fdcfd85433 rtc: rework rtc_register_device() resource management
rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres
callback for devm_rtc_allocate_device() takes care of resource release.

This doesn't correspond with the design behind devres where managed
structures should not be aware of being managed. The correct solution
here is to register a separate devres callback for unregistering the
device.

While at it: rename rtc_register_device() to devm_rtc_register_device()
and add it to the list of managed interfaces in devres.rst. This way we
can avoid any potential confusion of driver developers who may expect
there to exist a corresponding unregister function.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl
2020-11-19 12:50:12 +01:00

195 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2018 NXP.
*/
#include <dt-bindings/firmware/imx/rsrc.h>
#include <linux/arm-smccc.h>
#include <linux/firmware/imx/sci.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#define IMX_SC_TIMER_FUNC_GET_RTC_SEC1970 9
#define IMX_SC_TIMER_FUNC_SET_RTC_ALARM 8
#define IMX_SC_TIMER_FUNC_SET_RTC_TIME 6
#define IMX_SIP_SRTC 0xC2000002
#define IMX_SIP_SRTC_SET_TIME 0x0
#define SC_IRQ_GROUP_RTC 2
#define SC_IRQ_RTC 1
static struct imx_sc_ipc *rtc_ipc_handle;
static struct rtc_device *imx_sc_rtc;
struct imx_sc_msg_timer_get_rtc_time {
struct imx_sc_rpc_msg hdr;
u32 time;
} __packed;
struct imx_sc_msg_timer_rtc_set_alarm {
struct imx_sc_rpc_msg hdr;
u16 year;
u8 mon;
u8 day;
u8 hour;
u8 min;
u8 sec;
} __packed __aligned(4);
static int imx_sc_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct imx_sc_msg_timer_get_rtc_time msg;
struct imx_sc_rpc_msg *hdr = &msg.hdr;
int ret;
hdr->ver = IMX_SC_RPC_VERSION;
hdr->svc = IMX_SC_RPC_SVC_TIMER;
hdr->func = IMX_SC_TIMER_FUNC_GET_RTC_SEC1970;
hdr->size = 1;
ret = imx_scu_call_rpc(rtc_ipc_handle, &msg, true);
if (ret) {
dev_err(dev, "read rtc time failed, ret %d\n", ret);
return ret;
}
rtc_time64_to_tm(msg.time, tm);
return 0;
}
static int imx_sc_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct arm_smccc_res res;
/* pack 2 time parameters into 1 register, 16 bits for each */
arm_smccc_smc(IMX_SIP_SRTC, IMX_SIP_SRTC_SET_TIME,
((tm->tm_year + 1900) << 16) | (tm->tm_mon + 1),
(tm->tm_mday << 16) | tm->tm_hour,
(tm->tm_min << 16) | tm->tm_sec,
0, 0, 0, &res);
return res.a0;
}
static int imx_sc_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
return imx_scu_irq_group_enable(SC_IRQ_GROUP_RTC, SC_IRQ_RTC, enable);
}
static int imx_sc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
/*
* SCU firmware does NOT provide read alarm API, but .read_alarm
* callback is required by RTC framework to support alarm function,
* so just return here.
*/
return 0;
}
static int imx_sc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct imx_sc_msg_timer_rtc_set_alarm msg;
struct imx_sc_rpc_msg *hdr = &msg.hdr;
int ret;
struct rtc_time *alrm_tm = &alrm->time;
hdr->ver = IMX_SC_RPC_VERSION;
hdr->svc = IMX_SC_RPC_SVC_TIMER;
hdr->func = IMX_SC_TIMER_FUNC_SET_RTC_ALARM;
hdr->size = 3;
msg.year = alrm_tm->tm_year + 1900;
msg.mon = alrm_tm->tm_mon + 1;
msg.day = alrm_tm->tm_mday;
msg.hour = alrm_tm->tm_hour;
msg.min = alrm_tm->tm_min;
msg.sec = alrm_tm->tm_sec;
ret = imx_scu_call_rpc(rtc_ipc_handle, &msg, true);
if (ret) {
dev_err(dev, "set rtc alarm failed, ret %d\n", ret);
return ret;
}
ret = imx_sc_rtc_alarm_irq_enable(dev, alrm->enabled);
if (ret) {
dev_err(dev, "enable rtc alarm failed, ret %d\n", ret);
return ret;
}
return 0;
}
static const struct rtc_class_ops imx_sc_rtc_ops = {
.read_time = imx_sc_rtc_read_time,
.set_time = imx_sc_rtc_set_time,
.read_alarm = imx_sc_rtc_read_alarm,
.set_alarm = imx_sc_rtc_set_alarm,
.alarm_irq_enable = imx_sc_rtc_alarm_irq_enable,
};
static int imx_sc_rtc_alarm_notify(struct notifier_block *nb,
unsigned long event, void *group)
{
/* ignore non-rtc irq */
if (!((event & SC_IRQ_RTC) && (*(u8 *)group == SC_IRQ_GROUP_RTC)))
return 0;
rtc_update_irq(imx_sc_rtc, 1, RTC_IRQF | RTC_AF);
return 0;
}
static struct notifier_block imx_sc_rtc_alarm_sc_notifier = {
.notifier_call = imx_sc_rtc_alarm_notify,
};
static int imx_sc_rtc_probe(struct platform_device *pdev)
{
int ret;
ret = imx_scu_get_handle(&rtc_ipc_handle);
if (ret)
return ret;
device_init_wakeup(&pdev->dev, true);
imx_sc_rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(imx_sc_rtc))
return PTR_ERR(imx_sc_rtc);
imx_sc_rtc->ops = &imx_sc_rtc_ops;
imx_sc_rtc->range_min = 0;
imx_sc_rtc->range_max = U32_MAX;
ret = devm_rtc_register_device(imx_sc_rtc);
if (ret)
return ret;
imx_scu_irq_register_notifier(&imx_sc_rtc_alarm_sc_notifier);
return 0;
}
static const struct of_device_id imx_sc_dt_ids[] = {
{ .compatible = "fsl,imx8qxp-sc-rtc", },
{}
};
MODULE_DEVICE_TABLE(of, imx_sc_dt_ids);
static struct platform_driver imx_sc_rtc_driver = {
.driver = {
.name = "imx-sc-rtc",
.of_match_table = imx_sc_dt_ids,
},
.probe = imx_sc_rtc_probe,
};
module_platform_driver(imx_sc_rtc_driver);
MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
MODULE_DESCRIPTION("NXP i.MX System Controller RTC Driver");
MODULE_LICENSE("GPL");