kernel_samsung_a34x-permissive/drivers/misc/mediatek/dramc/dramc.c
2024-04-28 15:51:13 +02:00

80 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2019 MediaTek Inc.
* Author: Sagy Shih <sagy.shih@mediatek.com>
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/kallsyms.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/memblock.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/of_fdt.h>
#include <linux/of.h>
#include <asm/cacheflush.h>
#include <mt-plat/sync_write.h>
#include <dramc_io.h>
#include "mtk_dramc.h"
void __iomem *SLEEP_BASE_ADDR;
static DEFINE_SPINLOCK(dramc_lock);
int acquire_dram_ctrl(void)
{
unsigned int cnt;
unsigned long save_flags;
/* acquire SPM HW SEMAPHORE to avoid race condition */
spin_lock_irqsave(&dramc_lock, save_flags);
cnt = 2;
do {
if ((readl(PDEF_SPM_AP_SEMAPHORE) & 0x1) != 0x1) {
writel(0x1, PDEF_SPM_AP_SEMAPHORE);
if ((readl(PDEF_SPM_AP_SEMAPHORE) & 0x1) == 0x1)
break;
}
cnt--;
/* pr_info("[DRAMC] wait for SPM HW SEMAPHORE\n"); */
udelay(1);
} while (cnt > 0);
if (cnt == 0) {
spin_unlock_irqrestore(&dramc_lock, save_flags);
pr_info("[DRAMC] can NOT get SPM HW SEMAPHORE!\n");
return -1;
}
/* pr_info("[DRAMC] get SPM HW SEMAPHORE success!\n"); */
spin_unlock_irqrestore(&dramc_lock, save_flags);
return 0;
}
int release_dram_ctrl(void)
{
/* release SPM HW SEMAPHORE to avoid race condition */
if ((readl(PDEF_SPM_AP_SEMAPHORE) & 0x1) == 0x0) {
pr_err("[DRAMC] has NOT acquired SPM HW SEMAPHORE\n");
/* BUG(); */
}
writel(0x1, PDEF_SPM_AP_SEMAPHORE);
if ((readl(PDEF_SPM_AP_SEMAPHORE) & 0x1) == 0x1) {
pr_err("[DRAMC] release SPM HW SEMAPHORE fail!\n");
/* BUG(); */
}
/* pr_info("[DRAMC] release SPM HW SEMAPHORE success!\n"); */
return 0;
}