Commit 9e66fb52 authored by Julien Panis's avatar Julien Panis Committed by Greg Kroah-Hartman
Browse files

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: default avatarJulien Panis <jpanis@baylibre.com>
Message-ID: <20230511095126.105104-7-jpanis@baylibre.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dce54888

samples/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -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

samples/Makefile

+1 −0
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@@ -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/

samples/pfsm/.gitignore

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+2 −0
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# SPDX-License-Identifier: GPL-2.0

/pfsm-wakeup

samples/pfsm/Makefile

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# SPDX-License-Identifier: GPL-2.0

userprogs-always-y += pfsm-wakeup



userccflags += -I usr/include

samples/pfsm/pfsm-wakeup.c

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+125 −0
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// 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;

}