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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/arm/mach-davinci/cpuidle.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mach-davinci/cpuidle.c')
-rw-r--r-- | arch/arm/mach-davinci/cpuidle.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/cpuidle.c b/arch/arm/mach-davinci/cpuidle.c new file mode 100644 index 000000000..1b8f08532 --- /dev/null +++ b/arch/arm/mach-davinci/cpuidle.c @@ -0,0 +1,102 @@ +/* + * CPU idle for DaVinci SoCs + * + * Copyright (C) 2009 Texas Instruments Incorporated. http://www.ti.com/ + * + * Derived from Marvell Kirkwood CPU idle code + * (arch/arm/mach-kirkwood/cpuidle.c) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/cpuidle.h> +#include <linux/io.h> +#include <linux/export.h> +#include <asm/cpuidle.h> + +#include "cpuidle.h" +#include "ddr2.h" + +#define DAVINCI_CPUIDLE_MAX_STATES 2 + +static void __iomem *ddr2_reg_base; +static bool ddr2_pdown; + +static void davinci_save_ddr_power(int enter, bool pdown) +{ + u32 val; + + val = __raw_readl(ddr2_reg_base + DDR2_SDRCR_OFFSET); + + if (enter) { + if (pdown) + val |= DDR2_SRPD_BIT; + else + val &= ~DDR2_SRPD_BIT; + val |= DDR2_LPMODEN_BIT; + } else { + val &= ~(DDR2_SRPD_BIT | DDR2_LPMODEN_BIT); + } + + __raw_writel(val, ddr2_reg_base + DDR2_SDRCR_OFFSET); +} + +/* Actual code that puts the SoC in different idle states */ +static int davinci_enter_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + davinci_save_ddr_power(1, ddr2_pdown); + cpu_do_idle(); + davinci_save_ddr_power(0, ddr2_pdown); + + return index; +} + +static struct cpuidle_driver davinci_idle_driver = { + .name = "cpuidle-davinci", + .owner = THIS_MODULE, + .states[0] = ARM_CPUIDLE_WFI_STATE, + .states[1] = { + .enter = davinci_enter_idle, + .exit_latency = 10, + .target_residency = 10000, + .name = "DDR SR", + .desc = "WFI and DDR Self Refresh", + }, + .state_count = DAVINCI_CPUIDLE_MAX_STATES, +}; + +static int __init davinci_cpuidle_probe(struct platform_device *pdev) +{ + struct davinci_cpuidle_config *pdata = pdev->dev.platform_data; + + if (!pdata) { + dev_err(&pdev->dev, "cannot get platform data\n"); + return -ENOENT; + } + + ddr2_reg_base = pdata->ddr2_ctlr_base; + + ddr2_pdown = pdata->ddr2_pdown; + + return cpuidle_register(&davinci_idle_driver, NULL); +} + +static struct platform_driver davinci_cpuidle_driver = { + .driver = { + .name = "cpuidle-davinci", + }, +}; + +static int __init davinci_cpuidle_init(void) +{ + return platform_driver_probe(&davinci_cpuidle_driver, + davinci_cpuidle_probe); +} +device_initcall(davinci_cpuidle_init); + |