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}
126