samples/pfsm/pfsm-wakeup.c

   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
  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 }