Merge tag 'for-5.11-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
[linux-2.6-microblaze.git] / drivers / cpuidle / cpuidle-zynq.c
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 */
25 static 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
34 static 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 */
52 static 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
59 static struct platform_driver zynq_cpuidle_driver = {
60         .driver = {
61                 .name = "cpuidle-zynq",
62         },
63         .probe = zynq_cpuidle_probe,
64 };
65 builtin_platform_driver(zynq_cpuidle_driver);