forked from Minki/linux
8765caa5cb
Let's rename the function imx6q_set_int_mem_clk_lpm() to imx6_set_int_mem_clk_lpm() since it's actually common for all i.MX6 SoCs. Signed-off-by: Anson Huang <Anson.Huang@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
/*
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* Copyright (C) 2012 Freescale Semiconductor, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/cpuidle.h>
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#include <linux/module.h>
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#include <asm/cpuidle.h>
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#include <soc/imx/cpuidle.h>
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#include "common.h"
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#include "cpuidle.h"
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#include "hardware.h"
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static atomic_t master = ATOMIC_INIT(0);
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static DEFINE_SPINLOCK(master_lock);
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static int imx6q_enter_wait(struct cpuidle_device *dev,
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struct cpuidle_driver *drv, int index)
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{
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if (atomic_inc_return(&master) == num_online_cpus()) {
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/*
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* With this lock, we prevent other cpu to exit and enter
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* this function again and become the master.
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*/
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if (!spin_trylock(&master_lock))
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goto idle;
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imx6_set_lpm(WAIT_UNCLOCKED);
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cpu_do_idle();
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imx6_set_lpm(WAIT_CLOCKED);
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spin_unlock(&master_lock);
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goto done;
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}
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idle:
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cpu_do_idle();
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done:
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atomic_dec(&master);
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return index;
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}
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static struct cpuidle_driver imx6q_cpuidle_driver = {
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.name = "imx6q_cpuidle",
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.owner = THIS_MODULE,
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.states = {
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/* WFI */
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ARM_CPUIDLE_WFI_STATE,
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/* WAIT */
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{
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.exit_latency = 50,
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.target_residency = 75,
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.flags = CPUIDLE_FLAG_TIMER_STOP,
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.enter = imx6q_enter_wait,
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.name = "WAIT",
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.desc = "Clock off",
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},
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},
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.state_count = 2,
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.safe_state_index = 0,
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};
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/*
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* i.MX6 Q/DL has an erratum (ERR006687) that prevents the FEC from waking the
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* CPUs when they are in wait(unclocked) state. As the hardware workaround isn't
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* applicable to all boards, disable the deeper idle state when the workaround
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* isn't present and the FEC is in use.
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*/
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void imx6q_cpuidle_fec_irqs_used(void)
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{
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imx6q_cpuidle_driver.states[1].disabled = true;
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}
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EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_used);
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void imx6q_cpuidle_fec_irqs_unused(void)
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{
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imx6q_cpuidle_driver.states[1].disabled = false;
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}
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EXPORT_SYMBOL_GPL(imx6q_cpuidle_fec_irqs_unused);
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int __init imx6q_cpuidle_init(void)
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{
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/* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
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imx6_set_int_mem_clk_lpm(true);
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return cpuidle_register(&imx6q_cpuidle_driver, NULL);
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}
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