1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2a6c0f6ecSSekhar Nori /*
3a6c0f6ecSSekhar Nori * CPU idle for DaVinci SoCs
4a6c0f6ecSSekhar Nori *
5fb01eb36SAlexander A. Klimov * Copyright (C) 2009 Texas Instruments Incorporated. https://www.ti.com/
6a6c0f6ecSSekhar Nori *
7a6c0f6ecSSekhar Nori * Derived from Marvell Kirkwood CPU idle code
8a6c0f6ecSSekhar Nori * (arch/arm/mach-kirkwood/cpuidle.c)
9a6c0f6ecSSekhar Nori */
10a6c0f6ecSSekhar Nori
11a6c0f6ecSSekhar Nori #include <linux/kernel.h>
12a6c0f6ecSSekhar Nori #include <linux/init.h>
13a6c0f6ecSSekhar Nori #include <linux/platform_device.h>
14a6c0f6ecSSekhar Nori #include <linux/cpuidle.h>
15a6c0f6ecSSekhar Nori #include <linux/io.h>
16dc28094bSPaul Gortmaker #include <linux/export.h>
1719976c2aSRobert Lee #include <asm/cpuidle.h>
18a6c0f6ecSSekhar Nori
193acf731cSArnd Bergmann #include "cpuidle.h"
203acf731cSArnd Bergmann #include "ddr2.h"
21a6c0f6ecSSekhar Nori
22a6c0f6ecSSekhar Nori #define DAVINCI_CPUIDLE_MAX_STATES 2
23a6c0f6ecSSekhar Nori
24a6c0f6ecSSekhar Nori static void __iomem *ddr2_reg_base;
255af4a21cSDaniel Lezcano static bool ddr2_pdown;
26a6c0f6ecSSekhar Nori
davinci_save_ddr_power(int enter,bool pdown)27a6c0f6ecSSekhar Nori static void davinci_save_ddr_power(int enter, bool pdown)
28a6c0f6ecSSekhar Nori {
29a6c0f6ecSSekhar Nori u32 val;
30a6c0f6ecSSekhar Nori
31a6c0f6ecSSekhar Nori val = __raw_readl(ddr2_reg_base + DDR2_SDRCR_OFFSET);
32a6c0f6ecSSekhar Nori
33a6c0f6ecSSekhar Nori if (enter) {
34a6c0f6ecSSekhar Nori if (pdown)
35a6c0f6ecSSekhar Nori val |= DDR2_SRPD_BIT;
36a6c0f6ecSSekhar Nori else
37a6c0f6ecSSekhar Nori val &= ~DDR2_SRPD_BIT;
38a6c0f6ecSSekhar Nori val |= DDR2_LPMODEN_BIT;
39a6c0f6ecSSekhar Nori } else {
40a6c0f6ecSSekhar Nori val &= ~(DDR2_SRPD_BIT | DDR2_LPMODEN_BIT);
41a6c0f6ecSSekhar Nori }
42a6c0f6ecSSekhar Nori
43a6c0f6ecSSekhar Nori __raw_writel(val, ddr2_reg_base + DDR2_SDRCR_OFFSET);
44a6c0f6ecSSekhar Nori }
45a6c0f6ecSSekhar Nori
468d60143aSDaniel Lezcano /* Actual code that puts the SoC in different idle states */
davinci_enter_idle(struct cpuidle_device * dev,struct cpuidle_driver * drv,int index)47*26388a7cSPeter Zijlstra static __cpuidle int davinci_enter_idle(struct cpuidle_device *dev,
48c062d443SDaniel Lezcano struct cpuidle_driver *drv, int index)
498d60143aSDaniel Lezcano {
5036ce8d4fSDaniel Lezcano davinci_save_ddr_power(1, ddr2_pdown);
51c062d443SDaniel Lezcano cpu_do_idle();
5236ce8d4fSDaniel Lezcano davinci_save_ddr_power(0, ddr2_pdown);
538d60143aSDaniel Lezcano
548d60143aSDaniel Lezcano return index;
558d60143aSDaniel Lezcano }
568d60143aSDaniel Lezcano
578d60143aSDaniel Lezcano static struct cpuidle_driver davinci_idle_driver = {
588d60143aSDaniel Lezcano .name = "cpuidle-davinci",
598d60143aSDaniel Lezcano .owner = THIS_MODULE,
608d60143aSDaniel Lezcano .states[0] = ARM_CPUIDLE_WFI_STATE,
618d60143aSDaniel Lezcano .states[1] = {
628d60143aSDaniel Lezcano .enter = davinci_enter_idle,
638d60143aSDaniel Lezcano .exit_latency = 10,
647006b8a1SDaniel Lezcano .target_residency = 10000,
658d60143aSDaniel Lezcano .name = "DDR SR",
668d60143aSDaniel Lezcano .desc = "WFI and DDR Self Refresh",
678d60143aSDaniel Lezcano },
688d60143aSDaniel Lezcano .state_count = DAVINCI_CPUIDLE_MAX_STATES,
698d60143aSDaniel Lezcano };
708d60143aSDaniel Lezcano
davinci_cpuidle_probe(struct platform_device * pdev)71a6c0f6ecSSekhar Nori static int __init davinci_cpuidle_probe(struct platform_device *pdev)
72a6c0f6ecSSekhar Nori {
73a6c0f6ecSSekhar Nori struct davinci_cpuidle_config *pdata = pdev->dev.platform_data;
74a6c0f6ecSSekhar Nori
75a6c0f6ecSSekhar Nori if (!pdata) {
76a6c0f6ecSSekhar Nori dev_err(&pdev->dev, "cannot get platform data\n");
77a6c0f6ecSSekhar Nori return -ENOENT;
78a6c0f6ecSSekhar Nori }
79a6c0f6ecSSekhar Nori
80948c66dfSSekhar Nori ddr2_reg_base = pdata->ddr2_ctlr_base;
81a6c0f6ecSSekhar Nori
825af4a21cSDaniel Lezcano ddr2_pdown = pdata->ddr2_pdown;
83a6c0f6ecSSekhar Nori
843aec0345SDaniel Lezcano return cpuidle_register(&davinci_idle_driver, NULL);
85a6c0f6ecSSekhar Nori }
86a6c0f6ecSSekhar Nori
87a6c0f6ecSSekhar Nori static struct platform_driver davinci_cpuidle_driver = {
88a6c0f6ecSSekhar Nori .driver = {
89a6c0f6ecSSekhar Nori .name = "cpuidle-davinci",
90a6c0f6ecSSekhar Nori },
91a6c0f6ecSSekhar Nori };
92a6c0f6ecSSekhar Nori
davinci_cpuidle_init(void)93a6c0f6ecSSekhar Nori static int __init davinci_cpuidle_init(void)
94a6c0f6ecSSekhar Nori {
95a6c0f6ecSSekhar Nori return platform_driver_probe(&davinci_cpuidle_driver,
96a6c0f6ecSSekhar Nori davinci_cpuidle_probe);
97a6c0f6ecSSekhar Nori }
98a6c0f6ecSSekhar Nori device_initcall(davinci_cpuidle_init);
99a6c0f6ecSSekhar Nori
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