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
29 static const char * const dev_pfsm[] = {PMIC_A, PMIC_B, PMIC_C};
30
main(int argc,char * argv[])31 int 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
110 out_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
116 out:
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