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>

diff --git a/samples/Kconfig b/samples/Kconfig
index b2db430..3edf73a 100644 (file)
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -253,6 +253,12 @@ config SAMPLE_INTEL_MEI
        help
          Build a sample program to work with mei device.
 
+config SAMPLE_TPS6594_PFSM
+       bool "Build example program working with TPS6594 PFSM driver"
+       depends on HEADERS_INSTALL
+       help
+         Build a sample program to work with PFSM devices.
+
 config SAMPLE_WATCHDOG
        bool "watchdog sample"
        depends on CC_CAN_LINK

diff --git a/samples/Makefile b/samples/Makefile
index 7727f1a..0a551c2 100644 (file)
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_VIDEO_PCI_SKELETON)      += v4l/
 obj-y                                  += vfio-mdev/
 subdir-$(CONFIG_SAMPLE_VFS)            += vfs
 obj-$(CONFIG_SAMPLE_INTEL_MEI)         += mei/
+obj-$(CONFIG_SAMPLE_TPS6594_PFSM)      += pfsm/
 subdir-$(CONFIG_SAMPLE_WATCHDOG)       += watchdog
 subdir-$(CONFIG_SAMPLE_WATCH_QUEUE)    += watch_queue
 obj-$(CONFIG_SAMPLE_KMEMLEAK)          += kmemleak/

diff --git a/samples/pfsm/.gitignore b/samples/pfsm/.gitignore
new file mode 100644 (file)
index 0000000..f350a03
--- /dev/null
+++ b/samples/pfsm/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+/pfsm-wakeup

diff --git a/samples/pfsm/Makefile b/samples/pfsm/Makefile
new file mode 100644 (file)
index 0000000..213e8d9
--- /dev/null
+++ b/samples/pfsm/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+userprogs-always-y += pfsm-wakeup
+
+userccflags += -I usr/include

diff --git a/samples/pfsm/pfsm-wakeup.c b/samples/pfsm/pfsm-wakeup.c
new file mode 100644 (file)
index 0000000..299dd9e
--- /dev/null
+++ b/samples/pfsm/pfsm-wakeup.c
@@ -0,0 +1,125 @@
+// 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;
+}