rockchip/fiq_debugger/rk_fiq_debugger.c

/*
 * drivers/soc/rockchip/rk_fiq_debugger.c
 *
 * Serial Debugger Interface for Rockchip
 *
 * Copyright (C) 2012 ROCKCHIP, Inc.
 * Copyright (C) 2008 Google, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <stdarg.h>
#include <linux/cpu.h>
#include <linux/cpu_pm.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#include <linux/serial_reg.h>
#include <linux/slab.h>
#include <linux/stacktrace.h>
#include <linux/uaccess.h>
#include <linux/kfifo.h>
#include <linux/kthread.h>
#include <linux/sched/rt.h>
#include "fiq_debugger.h"
#include <linux/irqchip/arm-gic.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include "rk_fiq_debugger.h"
#include <linux/console.h>

#ifdef CONFIG_FIQ_DEBUGGER_TRUST_ZONE
#include <linux/rockchip/rockchip_sip.h>
#endif
#define UART_USR			0x1f /* In: UART Status Register */
#define UART_USR_RX_FIFO_FULL		0x10 /* Receive FIFO full */
#define UART_USR_RX_FIFO_NOT_EMPTY	0x08 /* Receive FIFO not empty */
#define UART_USR_TX_FIFO_EMPTY		0x04 /* Transmit FIFO empty */
#define UART_USR_TX_FIFO_NOT_FULL	0x02 /* Transmit FIFO not full */
#define UART_USR_BUSY			0x01 /* UART busy indicator */
#define UART_SRR			0x22 /* software reset register */
#define RK_UART_RFL			0x21 /* UART Receive Fifo Level Register */

struct rk_fiq_debugger {
	int irq;
	int baudrate;
	struct fiq_debugger_pdata pdata;
	void __iomem *debug_port_base;
	bool break_seen;
#ifdef CONFIG_RK_CONSOLE_THREAD
	struct task_struct *console_task;
#endif
};

static int rk_fiq_debugger_id;
static int serial_hwirq;

#ifdef CONFIG_FIQ_DEBUGGER_TRUST_ZONE
static bool tf_fiq_sup;
#endif

static inline void rk_fiq_write(struct rk_fiq_debugger *t,
	unsigned int val, unsigned int off)
{
	__raw_writel(val, t->debug_port_base + off * 4);
}

static inline unsigned int rk_fiq_read(struct rk_fiq_debugger *t,
	unsigned int off)
{
	return __raw_readl(t->debug_port_base + off * 4);
}

static inline unsigned int rk_fiq_read_lsr(struct rk_fiq_debugger *t)
{
	unsigned int lsr;

	lsr = rk_fiq_read(t, UART_LSR);
	if (lsr & UART_LSR_BI)
		t->break_seen = true;

	return lsr;
}

static int debug_port_init(struct platform_device *pdev)
{
	int dll = 0, dlm = 0;
	struct rk_fiq_debugger *t;

	console_lock();

	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);

	if (rk_fiq_read(t, UART_LSR) & UART_LSR_DR)
		(void)rk_fiq_read(t, UART_RX);

	switch (t->baudrate) {
	case 1500000:
		dll = 0x1;
		break;
	case 115200:
	default:
		dll = 0xd;
		break;
	}
	/* reset uart */
	rk_fiq_write(t, 0x07, UART_SRR);
	udelay(10);
	/* set uart to loop back mode */
	rk_fiq_write(t, 0x10, UART_MCR);

	rk_fiq_write(t, 0x83, UART_LCR);
	/* set baud rate */
	rk_fiq_write(t, dll, UART_DLL);
	rk_fiq_write(t, dlm, UART_DLM);
	rk_fiq_write(t, 0x03, UART_LCR);

	/* enable rx interrupt */
	rk_fiq_write(t, UART_IER_RDI, UART_IER);

	/*
	 * Interrupt on every character when received, but we can enable fifo for TX
	 * I found that if we enable the RX fifo, some problem may vanish such as when
	 * you continuously input characters in the command line the uart irq may be disable
	 * because of the uart irq is served when CPU is at IRQ exception, but it is
	 * found unregistered, so it is disable.
	 */
	rk_fiq_write(t, 0x01, UART_FCR);

	/* disbale loop back mode */
	rk_fiq_write(t, 0x0, UART_MCR);

	console_unlock();

	return 0;
}

static int debug_getc(struct platform_device *pdev)
{
	unsigned int lsr, usr, rfl, iir;
	struct rk_fiq_debugger *t;
	unsigned int temp;
	static unsigned int n;
	static char buf[32];

	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);
	/*
	 * Clear uart interrupt status
	 */
	iir = rk_fiq_read(t, UART_IIR);
	usr = rk_fiq_read(t, UART_USR);
	lsr = rk_fiq_read_lsr(t);

	/*
	 * There are ways to get Designware-based UARTs into a state where
	 * they are asserting UART_IIR_RX_TIMEOUT but there is no actual
	 * data available.  If we see such a case then we'll do a bogus
	 * read.  If we don't do this then the "RX TIMEOUT" interrupt will
	 * fire forever.
	 */
	if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT) {
		rfl = rk_fiq_read(t, RK_UART_RFL);
		if (!(lsr & (UART_LSR_DR | UART_LSR_BI)) && !(usr & 0x1) && (rfl == 0))
			rk_fiq_read(t, UART_RX);
	}

	if (lsr & UART_LSR_DR) {
		temp = rk_fiq_read(t, UART_RX);
		buf[n & 0x1f] = temp;
		n++;
		if (temp == 'q' && n > 2) {
			if ((buf[(n - 2) & 0x1f] == 'i') &&
			    (buf[(n - 3) & 0x1f] == 'f'))
				return FIQ_DEBUGGER_BREAK;
			else
				return temp;
		} else {
			return temp;
		}
	}

	return FIQ_DEBUGGER_NO_CHAR;
}

static void debug_putc(struct platform_device *pdev, unsigned int c)
{
	struct rk_fiq_debugger *t;
	unsigned int count = 10000;

	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);

	while (!(rk_fiq_read(t, UART_USR) & UART_USR_TX_FIFO_NOT_FULL) && count--)
		udelay(10);

	rk_fiq_write(t, c, UART_TX);
}

static int debug_getc_dummy(struct platform_device *pdev)
{
	return FIQ_DEBUGGER_NO_CHAR;
}

static void debug_putc_dummy(struct platform_device *pdev, unsigned int c)
{
}

static void debug_flush(struct platform_device *pdev)
{
	struct rk_fiq_debugger *t;
	unsigned int count = 10000;
	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);

	while (!(rk_fiq_read_lsr(t) & UART_LSR_TEMT) && count--)
		udelay(10);
}

#ifdef CONFIG_RK_CONSOLE_THREAD
#define FIFO_SIZE SZ_64K
#define TTY_FIFO_SIZE SZ_64K
static DEFINE_KFIFO(fifo, unsigned char, FIFO_SIZE);
static DEFINE_KFIFO(tty_fifo, unsigned char, TTY_FIFO_SIZE);
static bool console_thread_stop; /* write on console_write */
static bool console_thread_running; /* write on console_thread */
static unsigned int console_dropped_messages;

static int write_room(struct platform_device *pdev)
{
	return (TTY_FIFO_SIZE - kfifo_len(&tty_fifo));
}

static void console_putc(struct platform_device *pdev, unsigned int c)
{
	struct rk_fiq_debugger *t;
	unsigned int count = 2;		/* loop 2 times is enough */
	unsigned long us = 400;		/* the time to send 60 byte for baudrate 1500000 */

	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);

	if (t->baudrate == 115200)
		us = 5160;	/* the time to send 60 byte for baudrate 115200 */

	while (!(rk_fiq_read(t, UART_USR) & UART_USR_TX_FIFO_NOT_FULL) &&
	       count--)
		usleep_range(us, us + us / 20);

	rk_fiq_write(t, c, UART_TX);
}

static void console_flush(struct platform_device *pdev)
{
	struct rk_fiq_debugger *t;
	unsigned int count = 2;		/* loop 2 times is enough */
	unsigned long us = 428;		/* the time to send 64 byte for baudrate 1500000 */

	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);

	if (t->baudrate == 115200)
		us = 5500;	/* the time to send 64 byte for baudrate 115200 */

	while (!(rk_fiq_read_lsr(t) & UART_LSR_TEMT) && count--)
		usleep_range(us, us + us / 20);
}

static void console_put(struct platform_device *pdev,
			const char *s, unsigned int count)
{
	while (count--) {
		if (*s == '\n')
			console_putc(pdev, '\r');
		console_putc(pdev, *s++);
	}
}

static void debug_put(struct platform_device *pdev,
		      const char *s, unsigned int count)
{
	while (count--) {
		if (*s == '\n')
			debug_putc(pdev, '\r');
		debug_putc(pdev, *s++);
	}
}

static void wake_up_console_thread(struct task_struct *console_task)
{
	/*
	 * Avoid dead lock on console_task->pi_lock and console_lock
	 * when call printk() in try_to_wake_up().
	 *
	 * cpu0 hold console_lock, then try lock pi_lock fail:
	 *   printk()->vprintk_emit()->console_unlock()->try_to_wake_up()
	 *   ->lock(pi_lock)->deadlock
	 *
	 * cpu1 hold pi_lock, then try lock console_lock fail:
	 *   console_thread()->console_put()->usleep_range()->run_hrtimer()
	 *   ->hrtimer_wakeup()->try_to_wake_up()[hold_pi_lock]->printk()
	 *   ->vprintk_emit()->console_trylock_spining()->cpu_relax()->deadlock
	 *
	 * if cpu0 does not hold console_lock, cpu1 also deadlock on pi_lock:
	 *   ...->hrtimer_wakeup()->try_to_wake_up()[hold_pi_lock]->printk()
	 *   ->vprintk_emit()->console_unlock()->try_to_wake_up()
	 *   ->lock(pi_lock)->deadlock
	 *
	 * so when console_task is running on usleep_range(), printk()
	 * should not wakeup console_task to avoid lock(pi_lock) again,
	 * as run_hrtimer() will wakeup console_task later.
	 * console_thread_running==false guarantee that console_task
	 * is not running on usleep_range().
	 */
	if (!READ_ONCE(console_thread_running))
		wake_up_process(console_task);
}

static int console_thread(void *data)
{
	struct platform_device *pdev = data;
	char buf[64], c = 0;
	unsigned int len = 0, len_tty = 0;

	while (1) {
		unsigned int dropped;

		set_current_state(TASK_INTERRUPTIBLE);
		if (console_thread_stop || (kfifo_is_empty(&fifo) && kfifo_is_empty(&tty_fifo))) {
			smp_store_mb(console_thread_running, false);
			schedule();
			smp_store_mb(console_thread_running, true);
		}
		if (kthread_should_stop())
			break;
		set_current_state(TASK_RUNNING);

		while (!console_thread_stop && (!kfifo_is_empty(&fifo) || !kfifo_is_empty(&tty_fifo))) {
			while (!console_thread_stop && kfifo_get(&fifo, &c)) {
				console_put(pdev, &c, 1);
				if (c == '\n')
					break;
			}

			while (!console_thread_stop && kfifo_get(&tty_fifo, &c)) {
				console_putc(pdev, c);
				len_tty++;
				if (c == '\n')
					break;
			}
		}

		if (len_tty > 0)
			fiq_tty_wake_up(pdev);
		len_tty = 0;

		dropped = console_dropped_messages;
		if (dropped && !console_thread_stop) {
			console_dropped_messages = 0;
			smp_wmb();
			len = sprintf(buf, "** %u console messages dropped **\n",
				       dropped);
			console_put(pdev, buf, len);
		}
		if (!console_thread_stop)
			console_flush(pdev);
	}

	return 0;
}

static void console_write(struct platform_device *pdev, const char *s, unsigned int count)
{
	unsigned int fifo_count = FIFO_SIZE;
	unsigned char c;
	struct rk_fiq_debugger *t;

	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);

	if (console_thread_stop ||
	    oops_in_progress ||
	    system_state == SYSTEM_HALT ||
	    system_state == SYSTEM_POWER_OFF ||
	    system_state == SYSTEM_RESTART) {
		if (!console_thread_stop) {
			console_thread_stop = true;
			smp_wmb();
			debug_flush(pdev);
			while (fifo_count-- && kfifo_get(&fifo, &c))
				debug_put(pdev, &c, 1);
		}
		debug_put(pdev, s, count);
		debug_flush(pdev);
	} else if (count) {
		unsigned int ret = 0;

		if (kfifo_len(&fifo) + count <= FIFO_SIZE)
			ret = kfifo_in(&fifo, s, count);
		if (!ret) {
			console_dropped_messages++;
			smp_wmb();
		} else {
			wake_up_console_thread(t->console_task);
		}
	}
}

static int tty_write(struct platform_device *pdev, const char *s, int count)
{
	unsigned int ret = 0;
	struct rk_fiq_debugger *t;

	if (console_thread_stop)
		return count;
	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);

	if (count > 0) {
		if (kfifo_len(&tty_fifo) + count <= TTY_FIFO_SIZE)
			ret = kfifo_in(&tty_fifo, s, count);

		if (ret <= 0)
			return 0;
		wake_up_console_thread(t->console_task);
	}
	return count;
}
#endif

static void fiq_enable(struct platform_device *pdev, unsigned int irq, bool on)
{
	if (on)
		enable_irq(irq);
	else
		disable_irq(irq);
}

#ifdef CONFIG_FIQ_DEBUGGER_TRUST_ZONE
#ifdef CONFIG_ARM_SDE_INTERFACE
#include <linux/arm_sdei.h>
#include <asm/smp_plat.h>
#include <linux/suspend.h>
void fiq_debugger_fiq_get_(const char *fmt, ...);

static struct rk_fiq_sdei_st {
	u32 cur_cpu;
	u32 sw_cpu;
	u32 cpu_can_sw;
	int fiq_en;
	u32 event_id;
	u32 cpu_off_sw;
	u32 cpu_sw_event_id;
} rk_fiq_sdei;

int sdei_fiq_debugger_is_enabled(void)
{
	return rk_fiq_sdei.fiq_en;
}

static int fiq_sdei_event_callback(u32 event, struct pt_regs *regs, void *arg)
{
	int cpu_id = get_logical_index(read_cpuid_mpidr() &
				       MPIDR_HWID_BITMASK);
	fiq_debugger_fiq(regs, cpu_id);

	return 0;
}

static void rk_fiq_sdei_event_sw_cpu(int wait_disable)
{
	unsigned long affinity;
	int cnt = 100000;
	int ret = 0;

	do {
		ret = sdei_event_disable_nolock(rk_fiq_sdei.event_id);
		if (!ret)
			break;
		cnt--;
		udelay(20);
	} while (wait_disable && cnt);

	affinity = cpu_logical_map(rk_fiq_sdei.sw_cpu) & MPIDR_HWID_BITMASK;
	ret = sdei_event_routing_set_nolock(rk_fiq_sdei.event_id,
					    SDEI_EVENT_REGISTER_RM_PE,
					    affinity);
	ret = sdei_event_enable_nolock(rk_fiq_sdei.event_id);
	rk_fiq_sdei.cur_cpu = rk_fiq_sdei.sw_cpu;
}

static int fiq_sdei_sw_cpu_event_callback(u32 event, struct pt_regs *regs, void *arg)
{
	int cnt = 10000;
	int ret = 0;
	int cpu_id = event - rk_fiq_sdei.cpu_sw_event_id;

	WARN_ON(cpu_id !=
		get_logical_index(read_cpuid_mpidr() & MPIDR_HWID_BITMASK));

	if (cpu_id == rk_fiq_sdei.sw_cpu) {
		if (!rk_fiq_sdei.cpu_off_sw) {
			rk_fiq_sdei.cpu_can_sw = 1;
		} else {
			rk_fiq_sdei_event_sw_cpu(1);
			rk_fiq_sdei.cpu_off_sw = 0;
		}
	} else if (cpu_id == rk_fiq_sdei.cur_cpu && !rk_fiq_sdei.cpu_off_sw) {
		while (!rk_fiq_sdei.cpu_can_sw && cnt) {
			udelay(10);
			cnt--;
		};

		if (rk_fiq_sdei.cpu_can_sw) {
			rk_fiq_sdei_event_sw_cpu(0);
			rk_fiq_sdei.cpu_can_sw = 0;
		}
	}
	return ret;
}

static void _rk_fiq_dbg_sdei_switch_cpu(unsigned int cpu, int cpu_off)
{
	if (cpu == rk_fiq_sdei.cur_cpu)
		return;
	rk_fiq_sdei.sw_cpu = cpu;
	rk_fiq_sdei.cpu_can_sw = 0;
	rk_fiq_sdei.cpu_off_sw = cpu_off;
	sip_fiq_debugger_sdei_switch_cpu(rk_fiq_sdei.cur_cpu, cpu, cpu_off);
}

static void rk_fiq_dbg_sdei_switch_cpu(struct platform_device *pdev,
				       unsigned int cpu)
{
	_rk_fiq_dbg_sdei_switch_cpu(cpu, 0);
}

static int fiq_dbg_sdei_cpu_off_migrate_fiq(unsigned int cpu)
{
	unsigned int target_cpu;
	int cnt = 10000;

	if (rk_fiq_sdei.cur_cpu == cpu) {
		target_cpu = cpumask_any_but(cpu_online_mask, cpu);
		_rk_fiq_dbg_sdei_switch_cpu(target_cpu, 1);

		while (rk_fiq_sdei.cur_cpu == cpu && cnt) {
			udelay(10);
			cnt--;
		};
		if (!cnt)
			pr_err("%s: from %d to %d err!\n",
			       __func__, cpu, target_cpu);
	}

	return 0;
}

static int fiq_dbg_sdei_pm_callback(struct notifier_block *nb,
				    unsigned long mode, void *_unused)
{
	unsigned int target_cpu;

	switch (mode) {
	case PM_SUSPEND_PREPARE:
		target_cpu = cpumask_first(cpu_online_mask);
		if (target_cpu != 0)
			pr_err("%s: fiq for core !\n", __func__);
		else
			_rk_fiq_dbg_sdei_switch_cpu(target_cpu, 1);
		break;
	default:
	break;
	}
	return 0;
}

static struct notifier_block fiq_dbg_sdei_pm_nb = {
	.notifier_call = fiq_dbg_sdei_pm_callback,
};

static int fiq_debugger_sdei_enable(struct rk_fiq_debugger *t)
{
	int ret, cpu, i;
	int is_dyn_event = false;

	ret = sip_fiq_debugger_sdei_get_event_id(&rk_fiq_sdei.event_id,
						 &rk_fiq_sdei.cpu_sw_event_id,
						 NULL);

	if (ret) {
		pr_err("%s: get event id error!\n", __func__);
		return ret;
	}

	/* If we can't get a valid fiq event, use dynamic event instead */
	if (rk_fiq_sdei.event_id == 0) {
		ret = sdei_interrupt_bind(serial_hwirq, &rk_fiq_sdei.event_id);
		if (ret) {
			pr_err("%s: bind intr:%d error!\n", __func__, serial_hwirq);
			return ret;
		}

		is_dyn_event = true;
	}

	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
					"soc/rk_sdei_fiq_debugger",
					NULL,
					fiq_dbg_sdei_cpu_off_migrate_fiq);
	if (ret < 0) {
		pr_err("%s: cpuhp_setup_state_nocalls error! %d\n",
		       __func__, ret);
		return ret;
	}

	if (register_pm_notifier(&fiq_dbg_sdei_pm_nb)) {
		pr_err("%s: register pm notify error: %d!\n", __func__, ret);
		return ret;
	}

	ret = sdei_event_register(rk_fiq_sdei.event_id,
				  fiq_sdei_event_callback, NULL);

	if (ret) {
		pr_err("%s: sdei_event_register error!\n", __func__);
		unregister_pm_notifier(&fiq_dbg_sdei_pm_nb);
		return ret;
	}

	rk_fiq_sdei.cur_cpu = 0;

	ret = sdei_event_routing_set(rk_fiq_sdei.event_id,
				     SDEI_EVENT_REGISTER_RM_PE,
				     cpu_logical_map(rk_fiq_sdei.cur_cpu));

	if (ret) {
		pr_err("%s: sdei_event_routing_set error!\n", __func__);
		goto err;
	}

	ret = sdei_event_enable(rk_fiq_sdei.event_id);
	if (ret) {
		pr_err("%s: sdei_event_enable error!\n", __func__);
		goto err;
	}

	for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
		ret = sdei_event_register(rk_fiq_sdei.cpu_sw_event_id + cpu,
					  fiq_sdei_sw_cpu_event_callback,
					  NULL);
		if (ret) {
			pr_err("%s: cpu %d sdei_event_register error!\n",
			       __func__, cpu);
			goto cpu_sw_err;
		}
		ret = sdei_event_routing_set(rk_fiq_sdei.cpu_sw_event_id + cpu,
					     SDEI_EVENT_REGISTER_RM_PE,
					     cpu_logical_map(cpu));

		if (ret) {
			pr_err("%s:cpu %d fiq_sdei_event_routing_set error!\n",
			       __func__, cpu);
			goto cpu_sw_err;
		}

		ret = sdei_event_enable(rk_fiq_sdei.cpu_sw_event_id + cpu);
		if (ret) {
			pr_err("%s: cpu %d sdei_event_enable error!\n",
			       __func__, cpu);
			goto cpu_sw_err;
		}
	}

	t->pdata.switch_cpu = rk_fiq_dbg_sdei_switch_cpu;
	rk_fiq_sdei.fiq_en = 1;
	return 0;
cpu_sw_err:
	for (i = 0; i < cpu; i++)
		sdei_event_unregister(rk_fiq_sdei.cpu_sw_event_id + i);
err:
	unregister_pm_notifier(&fiq_dbg_sdei_pm_nb);
	sdei_event_unregister(rk_fiq_sdei.event_id);

	if (is_dyn_event)
		sdei_interrupt_release(rk_fiq_sdei.event_id);

	return ret;
}

#else
static inline int fiq_debugger_sdei_enable(struct rk_fiq_debugger *t)
{
	return -EINVAL;
}
#endif

static void rk_fiq_debugger_switch_cpu(struct platform_device *pdev,
				       unsigned int cpu)
{
	sip_fiq_debugger_switch_cpu(cpu);
}

static void rk_fiq_debugger_enable_debug(struct platform_device *pdev, bool val)
{
	sip_fiq_debugger_enable_debug(val);
}

static void fiq_debugger_uart_irq_tf(struct pt_regs *_pt_regs, unsigned long cpu)
{
	fiq_debugger_fiq(_pt_regs, cpu);
}

static int rk_fiq_debugger_uart_dev_resume(struct platform_device *pdev)
{
	struct rk_fiq_debugger *t;

	t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);
	sip_fiq_debugger_uart_irq_tf_init(serial_hwirq,
					  fiq_debugger_uart_irq_tf);
	return 0;
}

/*
 * We don't need to migrate fiq before cpuidle, because EL3 can promise to
 * resume all fiq configure. We don't want fiq to break kernel cpu_resume(),
 * so that fiq would be disabled in EL3 on purpose when cpu resume. We enable
 * it here since everything is okay.
 */
static int fiq_debugger_cpuidle_resume_fiq(struct notifier_block *nb,
					   unsigned long action, void *hcpu)
{
	switch (action) {
	case CPU_PM_EXIT:
		if ((sip_fiq_debugger_is_enabled()) &&
		    (sip_fiq_debugger_get_target_cpu() == smp_processor_id()))
			sip_fiq_debugger_enable_fiq(true, smp_processor_id());
		break;
	default:
		break;
	}

	return NOTIFY_OK;
}

/*
 * We must migrate fiq before cpu offline, because EL3 doesn't promise to
 * resume all fiq configure at this sisutation. Here, we migrate fiq to any
 * online cpu.
 */
static int fiq_debugger_cpu_offine_migrate_fiq(unsigned int cpu)
{
	unsigned int target_cpu;

	if ((sip_fiq_debugger_is_enabled()) &&
	    (sip_fiq_debugger_get_target_cpu() == cpu)) {
		target_cpu = cpumask_any_but(cpu_online_mask, cpu);
		sip_fiq_debugger_switch_cpu(target_cpu);
	}

	return 0;
}

static struct notifier_block fiq_debugger_pm_notifier = {
	.notifier_call = fiq_debugger_cpuidle_resume_fiq,
	.priority = 100,
};

static int rk_fiq_debugger_register_cpu_pm_notify(void)
{
	int err;

	err = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
					"soc/rk_fiq_debugger",
					NULL,
					fiq_debugger_cpu_offine_migrate_fiq);
	if (err < 0) {
		pr_err("fiq debugger register cpu notifier failed!\n");
		return err;
	}

	err = cpu_pm_register_notifier(&fiq_debugger_pm_notifier);
	if (err) {
		pr_err("fiq debugger register pm notifier failed!\n");
		return err;
	}

	return 0;
}

static int fiq_debugger_bind_sip_smc(struct rk_fiq_debugger *t,
				     phys_addr_t phy_base,
				     int hwirq,
				     int signal_irq,
				     unsigned int baudrate)
{
	int err;

	err = sip_fiq_debugger_request_share_memory();
	if (err) {
		pr_err("fiq debugger request share memory failed: %d\n", err);
		goto exit;
	}

	err = rk_fiq_debugger_register_cpu_pm_notify();
	if (err) {
		pr_err("fiq debugger register cpu pm notify failed: %d\n", err);
		goto exit;
	}

	err = sip_fiq_debugger_uart_irq_tf_init(hwirq,
				fiq_debugger_uart_irq_tf);
	if (err) {
		pr_err("fiq debugger bind fiq to trustzone failed: %d\n", err);
		goto exit;
	}

	t->pdata.uart_dev_resume = rk_fiq_debugger_uart_dev_resume;
	t->pdata.switch_cpu = rk_fiq_debugger_switch_cpu;
	t->pdata.enable_debug = rk_fiq_debugger_enable_debug;
	sip_fiq_debugger_set_print_port(phy_base, baudrate);

	pr_info("fiq debugger fiq mode enabled\n");

	return 0;

exit:
	t->pdata.switch_cpu = NULL;
	t->pdata.enable_debug = NULL;

	return err;
}
#endif

static void rk_serial_debug_init(void __iomem *base, phys_addr_t phy_base,
				 int irq, int signal_irq,
				 int wakeup_irq, unsigned int baudrate)
{
	struct rk_fiq_debugger *t = NULL;
	struct platform_device *pdev = NULL;
	struct resource *res = NULL;
	int res_count = 0;
#ifdef CONFIG_FIQ_DEBUGGER_TRUST_ZONE
	int ret = 0;
#endif

	if (!base) {
		pr_err("Invalid fiq debugger uart base\n");
		return;
	}

	t = kzalloc(sizeof(struct rk_fiq_debugger), GFP_KERNEL);
	if (!t) {
		pr_err("Failed to allocate for fiq debugger\n");
		return;
	}

	t->irq = irq;
	t->baudrate = baudrate;
	t->pdata.uart_init = debug_port_init;
	t->pdata.uart_getc = debug_getc;
	t->pdata.uart_putc = debug_putc;
#ifndef CONFIG_RK_CONSOLE_THREAD
	t->pdata.uart_flush = debug_flush;
#endif
	t->pdata.fiq_enable = fiq_enable;
	t->pdata.force_irq = NULL;
	t->debug_port_base = base;

	res = kzalloc(sizeof(struct resource) * 3, GFP_KERNEL);
	if (!res) {
		pr_err("Failed to alloc fiq debugger resources\n");
		goto out2;
	}

	pdev = kzalloc(sizeof(struct platform_device), GFP_KERNEL);
	if (!pdev) {
		pr_err("Failed to alloc fiq debugger platform device\n");
		goto out3;
	}

	/* clear busy interrupt, make sure all interrupts are disabled */
	rk_fiq_read(t, UART_USR);
#ifdef CONFIG_FIQ_DEBUGGER_TRUST_ZONE
	if ((signal_irq > 0) && (serial_hwirq > 0)) {
		ret = fiq_debugger_sdei_enable(t);
		if (ret)
			ret = fiq_debugger_bind_sip_smc(t, phy_base,
							serial_hwirq,
							signal_irq, baudrate);
		if (ret)
			tf_fiq_sup = false;
		else
			tf_fiq_sup = true;
	}
#endif

	if (irq > 0) {
		res[0].flags = IORESOURCE_IRQ;
		res[0].start = irq;
		res[0].end = irq;
#if defined(CONFIG_FIQ_GLUE)
		if (signal_irq > 0)
			res[0].name = "fiq";
		else
			res[0].name = "uart_irq";
#elif defined(CONFIG_FIQ_DEBUGGER_TRUST_ZONE)
		if (tf_fiq_sup && (signal_irq > 0))
			res[0].name = "fiq";
		else
			res[0].name = "uart_irq";
#else
		res[0].name = "uart_irq";
#endif
		res_count++;
	}

	if (signal_irq > 0) {
		res[1].flags = IORESOURCE_IRQ;
		res[1].start = signal_irq;
		res[1].end = signal_irq;
		res[1].name = "signal";
		res_count++;
	}

	if (wakeup_irq > 0) {
		res[2].flags = IORESOURCE_IRQ;
		res[2].start = wakeup_irq;
		res[2].end = wakeup_irq;
		res[2].name = "wakeup";
		res_count++;
	}

#ifdef CONFIG_RK_CONSOLE_THREAD
	t->console_task = kthread_run(console_thread, pdev, "kconsole");
	if (!IS_ERR(t->console_task)) {
		t->pdata.console_write = console_write;
		t->pdata.tty_write = tty_write;
		t->pdata.write_room = write_room;
	}
#endif

	pdev->name = "fiq_debugger";
	pdev->id = rk_fiq_debugger_id++;
	pdev->dev.platform_data = &t->pdata;
	pdev->resource = res;
	pdev->num_resources = res_count;
	if (platform_device_register(pdev)) {
		pr_err("Failed to register fiq debugger\n");
		goto out4;
	}
	return;

out4:
	kfree(pdev);
out3:
	kfree(res);
out2:
	kfree(t);
}

static void rk_serial_debug_init_dummy(void)
{
	struct rk_fiq_debugger *t = NULL;
	struct platform_device *pdev = NULL;

	t = kzalloc(sizeof(*t), GFP_KERNEL);
	if (!t) {
		pr_err("Failed to allocate for fiq debugger\n");
		return;
	}

	t->pdata.uart_getc = debug_getc_dummy;
	t->pdata.uart_putc = debug_putc_dummy;

	pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
	if (!pdev) {
		pr_err("Failed to alloc fiq debugger platform device\n");
		goto out2;
	}

	pdev->name = "fiq_debugger";
	pdev->id = rk_fiq_debugger_id++;
	pdev->dev.platform_data = &t->pdata;
	if (platform_device_register(pdev)) {
		pr_err("Failed to register fiq debugger\n");
		goto out3;
	}
	return;

out3:
	kfree(pdev);
out2:
	kfree(t);
}

#if defined(CONFIG_OF)
static const struct of_device_id rk_fiqdbg_of_match[] = {
	{ .compatible = "rockchip,fiq-debugger", },
	{},
};
MODULE_DEVICE_TABLE(of, rk_fiqdbg_of_match);
#endif

static int __init rk_fiqdbg_probe(struct platform_device *pdev)
{
	void __iomem *base;
	struct device_node *np = pdev->dev.of_node;
	unsigned int id, ok = 0;
	int irq, signal_irq = -1, wake_irq = -1;
	unsigned int baudrate = 0, irq_mode = 0;
	phys_addr_t phy_base = 0;
	int serial_id;
	struct clk *clk;
	struct clk *pclk;
	struct of_phandle_args oirq;
	struct resource res;

	if (!of_device_is_available(np)) {
		pr_err("fiq-debugger is disabled in device tree\n");
		return -ENODEV;
	}

	if (of_property_read_u32(np, "rockchip,serial-id", &serial_id))
		return -EINVAL;

	if (serial_id == -1) {
		rk_serial_debug_init_dummy();
		return 0;
	}

	if (of_property_read_u32(np, "rockchip,irq-mode-enable", &irq_mode))
		irq_mode = -1;

	signal_irq = irq_of_parse_and_map(np, 0);
	if (!signal_irq)
		return -EINVAL;

	if (of_property_read_u32(np, "rockchip,wake-irq", &wake_irq))
		wake_irq = -1;

	if (of_property_read_u32(np, "rockchip,baudrate", &baudrate))
		baudrate = -1;

	np = NULL;

	do {
		np = of_find_node_by_name(np, "serial");
		if (np) {
			id = of_alias_get_id(np, "serial");
			if (id == serial_id) {
				ok = 1;
				break;
			}
		}
	} while(np);

	if (!ok)
		return -EINVAL;

	if (of_device_is_available(np)) {
		pr_err("uart%d is enabled, please disable it\n", serial_id);
		return -EINVAL;
	}

	/* parse serial hw irq */
	if (irq_mode != 1 && !of_irq_parse_one(np, 0, &oirq))
		serial_hwirq = oirq.args[1] + 32;

	/* parse serial phy base address */
	if (!of_address_to_resource(np, 0, &res))
		phy_base = res.start;

	pclk = of_clk_get_by_name(np, "apb_pclk");
	clk = of_clk_get_by_name(np, "baudclk");
	if (unlikely(IS_ERR(clk)) || unlikely(IS_ERR(pclk))) {
		pr_err("fiq-debugger get clock fail\n");
		return -EINVAL;
	}

	clk_prepare_enable(clk);
	clk_prepare_enable(pclk);

	irq = irq_of_parse_and_map(np, 0);
	if (!irq)
		return -EINVAL;

	base = of_iomap(np, 0);
	if (base)
		rk_serial_debug_init(base, phy_base,
				     irq, signal_irq, wake_irq, baudrate);
	return 0;
}

static struct platform_driver rk_fiqdbg_driver = {
	.driver = {
		.name   = "rk-fiq-debugger",
		.of_match_table = of_match_ptr(rk_fiqdbg_of_match),
	},
};

static int __init rk_fiqdbg_init(void)
{
	return platform_driver_probe(&rk_fiqdbg_driver,
				     rk_fiqdbg_probe);
}

#if defined(CONFIG_FIQ_DEBUGGER_TRUST_ZONE) && defined(CONFIG_ARM_SDE_INTERFACE)
fs_initcall(rk_fiqdbg_init);
#else
subsys_initcall(rk_fiqdbg_init); /* after of_platform_default_populate_init */
#endif

static void __exit rk_fiqdbg_exit(void)
{
	platform_driver_unregister(&rk_fiqdbg_driver);
}
module_exit(rk_fiqdbg_exit);

MODULE_AUTHOR("Huibin Hong <huibin.hong@rock-chips.com>");
MODULE_DESCRIPTION("Rockchip FIQ Debugger");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rk-fiq-debugger");