1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2012-2013 Xilinx
 4 *
 5 * CPU idle support for Xilinx Zynq
 6 *
 7 * based on arch/arm/mach-at91/cpuidle.c
 8 *
 
 
 
 
 
 
 
 
 
 
 
 
 9 * The cpu idle uses wait-for-interrupt and RAM self refresh in order
10 * to implement two idle states -
11 * #1 wait-for-interrupt
12 * #2 wait-for-interrupt and RAM self refresh
13 *
14 * Maintainer: Michal Simek <michal.simek@xilinx.com>
15 */
16
17#include <linux/init.h>
 
18#include <linux/cpuidle.h>
19#include <linux/platform_device.h>
 
20#include <asm/cpuidle.h>
21
22#define ZYNQ_MAX_STATES		2
23
24/* Actual code that puts the SoC in different idle states */
25static int zynq_enter_idle(struct cpuidle_device *dev,
26			   struct cpuidle_driver *drv, int index)
27{
 
 
 
28	/* Add code for DDR self refresh start */
29	cpu_do_idle();
30
 
 
 
31	return index;
32}
33
34static struct cpuidle_driver zynq_idle_driver = {
35	.name = "zynq_idle",
36	.owner = THIS_MODULE,
37	.states = {
38		ARM_CPUIDLE_WFI_STATE,
39		{
40			.enter			= zynq_enter_idle,
41			.exit_latency		= 10,
42			.target_residency	= 10000,
 
 
43			.name			= "RAM_SR",
44			.desc			= "WFI and RAM Self Refresh",
45		},
46	},
47	.safe_state_index = 0,
48	.state_count = ZYNQ_MAX_STATES,
49};
50
51/* Initialize CPU idle by registering the idle states */
52static int zynq_cpuidle_probe(struct platform_device *pdev)
53{
54	pr_info("Xilinx Zynq CpuIdle Driver started\n");
55
56	return cpuidle_register(&zynq_idle_driver, NULL);
57}
58
59static struct platform_driver zynq_cpuidle_driver = {
60	.driver = {
61		.name = "cpuidle-zynq",
 
62	},
63	.probe = zynq_cpuidle_probe,
64};
65builtin_platform_driver(zynq_cpuidle_driver);
 

 
 1/*
 2 * Copyright (C) 2012-2013 Xilinx
 3 *
 4 * CPU idle support for Xilinx Zynq
 5 *
 6 * based on arch/arm/mach-at91/cpuidle.c
 7 *
 8 * This program is free software; you can redistribute it and/or modify it
 9 * under the terms and conditions of the GNU General Public License,
10 * version 2, as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * this program.  If not, see <http://www.gnu.org/licenses/>.
19 *
20 * The cpu idle uses wait-for-interrupt and RAM self refresh in order
21 * to implement two idle states -
22 * #1 wait-for-interrupt
23 * #2 wait-for-interrupt and RAM self refresh
24 *
25 * Maintainer: Michal Simek <michal.simek@xilinx.com>
26 */
27
28#include <linux/init.h>
29#include <linux/cpu_pm.h>
30#include <linux/cpuidle.h>
31#include <linux/platform_device.h>
32#include <asm/proc-fns.h>
33#include <asm/cpuidle.h>
34
35#define ZYNQ_MAX_STATES		2
36
37/* Actual code that puts the SoC in different idle states */
38static int zynq_enter_idle(struct cpuidle_device *dev,
39			   struct cpuidle_driver *drv, int index)
40{
41	/* Devices must be stopped here */
42	cpu_pm_enter();
43
44	/* Add code for DDR self refresh start */
45	cpu_do_idle();
46
47	/* Add code for DDR self refresh stop */
48	cpu_pm_exit();
49
50	return index;
51}
52
53static struct cpuidle_driver zynq_idle_driver = {
54	.name = "zynq_idle",
55	.owner = THIS_MODULE,
56	.states = {
57		ARM_CPUIDLE_WFI_STATE,
58		{
59			.enter			= zynq_enter_idle,
60			.exit_latency		= 10,
61			.target_residency	= 10000,
62			.flags			= CPUIDLE_FLAG_TIME_VALID |
63						  CPUIDLE_FLAG_TIMER_STOP,
64			.name			= "RAM_SR",
65			.desc			= "WFI and RAM Self Refresh",
66		},
67	},
68	.safe_state_index = 0,
69	.state_count = ZYNQ_MAX_STATES,
70};
71
72/* Initialize CPU idle by registering the idle states */
73static int zynq_cpuidle_probe(struct platform_device *pdev)
74{
75	pr_info("Xilinx Zynq CpuIdle Driver started\n");
76
77	return cpuidle_register(&zynq_idle_driver, NULL);
78}
79
80static struct platform_driver zynq_cpuidle_driver = {
81	.driver = {
82		.name = "cpuidle-zynq",
83		.owner = THIS_MODULE,
84	},
85	.probe = zynq_cpuidle_probe,
86};
87
88module_platform_driver(zynq_cpuidle_driver);