1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * TPS6594 PFSM userspace example
  4 *
  5 * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
  6 *
  7 * This example shows how to use PFSMs from a userspace application,
  8 * on TI j721s2 platform. The PMIC is armed to be triggered by a RTC
  9 * alarm to execute state transition (RETENTION to ACTIVE).
 10 */
 11
 12#include <fcntl.h>
 13#include <stdio.h>
 14#include <sys/ioctl.h>
 15#include <unistd.h>
 16
 17#include <linux/rtc.h>
 18#include <linux/tps6594_pfsm.h>
 19
 20#define ALARM_DELTA_SEC 30
 21
 22#define RTC_A "/dev/rtc0"
 23
 24#define PMIC_NB 3
 25#define PMIC_A "/dev/pfsm-0-0x48"
 26#define PMIC_B "/dev/pfsm-0-0x4c"
 27#define PMIC_C "/dev/pfsm-2-0x58"
 28
 29static const char * const dev_pfsm[] = {PMIC_A, PMIC_B, PMIC_C};
 30
 31int main(int argc, char *argv[])
 32{
 33	int i, ret, fd_rtc, fd_pfsm[PMIC_NB] = { 0 };
 34	struct rtc_time rtc_tm;
 35	struct pmic_state_opt pmic_opt = { 0 };
 36	unsigned long data;
 37
 38	fd_rtc = open(RTC_A, O_RDONLY);
 39	if (fd_rtc < 0) {
 40		perror("Failed to open RTC device.");
 41		goto out;
 42	}
 43
 44	for (i = 0 ; i < PMIC_NB ; i++) {
 45		fd_pfsm[i] = open(dev_pfsm[i], O_RDWR);
 46		if (fd_pfsm[i] < 0) {
 47			perror("Failed to open PFSM device.");
 48			goto out;
 49		}
 50	}
 51
 52	/* Read RTC date/time */
 53	ret = ioctl(fd_rtc, RTC_RD_TIME, &rtc_tm);
 54	if (ret < 0) {
 55		perror("Failed to read RTC date/time.");
 56		goto out;
 57	}
 58	printf("Current RTC date/time is %d-%d-%d, %02d:%02d:%02d.\n",
 59	       rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
 60	       rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
 61
 62	/* Set RTC alarm to ALARM_DELTA_SEC sec in the future, and check for rollover */
 63	rtc_tm.tm_sec += ALARM_DELTA_SEC;
 64	if (rtc_tm.tm_sec >= 60) {
 65		rtc_tm.tm_sec %= 60;
 66		rtc_tm.tm_min++;
 67	}
 68	if (rtc_tm.tm_min == 60) {
 69		rtc_tm.tm_min = 0;
 70		rtc_tm.tm_hour++;
 71	}
 72	if (rtc_tm.tm_hour == 24)
 73		rtc_tm.tm_hour = 0;
 74	ret = ioctl(fd_rtc, RTC_ALM_SET, &rtc_tm);
 75	if (ret < 0) {
 76		perror("Failed to set RTC alarm.");
 77		goto out;
 78	}
 79
 80	/* Enable alarm interrupts */
 81	ret = ioctl(fd_rtc, RTC_AIE_ON, 0);
 82	if (ret < 0) {
 83		perror("Failed to enable alarm interrupts.");
 84		goto out;
 85	}
 86	printf("Waiting %d seconds for alarm...\n", ALARM_DELTA_SEC);
 87
 88	/*
 89	 * Set RETENTION state with options for PMIC_C/B/A respectively.
 90	 * Since PMIC_A is master, it should be the last one to be configured.
 91	 */
 92	pmic_opt.ddr_retention = 1;
 93	for (i = PMIC_NB - 1 ; i >= 0 ; i--) {
 94		printf("Set RETENTION state for PMIC_%d.\n", i);
 95		sleep(1);
 96		ret = ioctl(fd_pfsm[i], PMIC_SET_RETENTION_STATE, &pmic_opt);
 97		if (ret < 0) {
 98			perror("Failed to set RETENTION state.");
 99			goto out_reset;
100		}
101	}
102
103	/* This blocks until the alarm ring causes an interrupt */
104	ret = read(fd_rtc, &data, sizeof(unsigned long));
105	if (ret < 0)
106		perror("Failed to get RTC alarm.");
107	else
108		puts("Alarm rang.\n");
109
110out_reset:
111	ioctl(fd_rtc, RTC_AIE_OFF, 0);
112
113	/* Set ACTIVE state for PMIC_A */
114	ioctl(fd_pfsm[0], PMIC_SET_ACTIVE_STATE, 0);
115
116out:
117	for (i = 0 ; i < PMIC_NB ; i++)
118		if (fd_pfsm[i])
119			close(fd_pfsm[i]);
120
121	if (fd_rtc)
122		close(fd_rtc);
123
124	return 0;
125}