linux-next/samples/pfsm/pfsm-wakeup.c
Julien Panis 9e66fb5244 samples: Add userspace example for TI TPS6594 PFSM
This patch adds an example showing how to use PFSM devices
from a userspace application. The PMIC is armed to be triggered
by a RTC alarm to execute state transition.

Signed-off-by: Julien Panis <jpanis@baylibre.com>
Message-ID: <20230511095126.105104-7-jpanis@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-15 13:41:53 +02:00

126 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* TPS6594 PFSM userspace example
*
* Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
*
* This example shows how to use PFSMs from a userspace application,
* on TI j721s2 platform. The PMIC is armed to be triggered by a RTC
* alarm to execute state transition (RETENTION to ACTIVE).
*/
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <linux/rtc.h>
#include <linux/tps6594_pfsm.h>
#define ALARM_DELTA_SEC 30
#define RTC_A "/dev/rtc0"
#define PMIC_NB 3
#define PMIC_A "/dev/pfsm-0-0x48"
#define PMIC_B "/dev/pfsm-0-0x4c"
#define PMIC_C "/dev/pfsm-2-0x58"
static const char * const dev_pfsm[] = {PMIC_A, PMIC_B, PMIC_C};
int main(int argc, char *argv[])
{
int i, ret, fd_rtc, fd_pfsm[PMIC_NB] = { 0 };
struct rtc_time rtc_tm;
struct pmic_state_opt pmic_opt = { 0 };
unsigned long data;
fd_rtc = open(RTC_A, O_RDONLY);
if (fd_rtc < 0) {
perror("Failed to open RTC device.");
goto out;
}
for (i = 0 ; i < PMIC_NB ; i++) {
fd_pfsm[i] = open(dev_pfsm[i], O_RDWR);
if (fd_pfsm[i] < 0) {
perror("Failed to open PFSM device.");
goto out;
}
}
/* Read RTC date/time */
ret = ioctl(fd_rtc, RTC_RD_TIME, &rtc_tm);
if (ret < 0) {
perror("Failed to read RTC date/time.");
goto out;
}
printf("Current RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
/* Set RTC alarm to ALARM_DELTA_SEC sec in the future, and check for rollover */
rtc_tm.tm_sec += ALARM_DELTA_SEC;
if (rtc_tm.tm_sec >= 60) {
rtc_tm.tm_sec %= 60;
rtc_tm.tm_min++;
}
if (rtc_tm.tm_min == 60) {
rtc_tm.tm_min = 0;
rtc_tm.tm_hour++;
}
if (rtc_tm.tm_hour == 24)
rtc_tm.tm_hour = 0;
ret = ioctl(fd_rtc, RTC_ALM_SET, &rtc_tm);
if (ret < 0) {
perror("Failed to set RTC alarm.");
goto out;
}
/* Enable alarm interrupts */
ret = ioctl(fd_rtc, RTC_AIE_ON, 0);
if (ret < 0) {
perror("Failed to enable alarm interrupts.");
goto out;
}
printf("Waiting %d seconds for alarm...\n", ALARM_DELTA_SEC);
/*
* Set RETENTION state with options for PMIC_C/B/A respectively.
* Since PMIC_A is master, it should be the last one to be configured.
*/
pmic_opt.ddr_retention = 1;
for (i = PMIC_NB - 1 ; i >= 0 ; i--) {
printf("Set RETENTION state for PMIC_%d.\n", i);
sleep(1);
ret = ioctl(fd_pfsm[i], PMIC_SET_RETENTION_STATE, &pmic_opt);
if (ret < 0) {
perror("Failed to set RETENTION state.");
goto out_reset;
}
}
/* This blocks until the alarm ring causes an interrupt */
ret = read(fd_rtc, &data, sizeof(unsigned long));
if (ret < 0)
perror("Failed to get RTC alarm.");
else
puts("Alarm rang.\n");
out_reset:
ioctl(fd_rtc, RTC_AIE_OFF, 0);
/* Set ACTIVE state for PMIC_A */
ioctl(fd_pfsm[0], PMIC_SET_ACTIVE_STATE, 0);
out:
for (i = 0 ; i < PMIC_NB ; i++)
if (fd_pfsm[i])
close(fd_pfsm[i]);
if (fd_rtc)
close(fd_rtc);
return 0;
}