pm_ipi.c

/*
 * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <bakery_lock.h>
#include <mmio.h>
#include <platform.h>
#include <arch_helpers.h>
#include "pm_ipi.h"
#include "../zynqmp_private.h"

/* IPI message buffers */
#define IPI_BUFFER_BASEADDR	0xFF990000U

#define IPI_BUFFER_RPU_0_BASE	(IPI_BUFFER_BASEADDR + 0x0U)
#define IPI_BUFFER_RPU_1_BASE	(IPI_BUFFER_BASEADDR + 0x200U)
#define IPI_BUFFER_APU_BASE	(IPI_BUFFER_BASEADDR + 0x400U)
#define IPI_BUFFER_PL_0_BASE	(IPI_BUFFER_BASEADDR + 0x600U)
#define IPI_BUFFER_PL_1_BASE	(IPI_BUFFER_BASEADDR + 0x800U)
#define IPI_BUFFER_PL_2_BASE	(IPI_BUFFER_BASEADDR + 0xA00U)
#define IPI_BUFFER_PL_3_BASE	(IPI_BUFFER_BASEADDR + 0xC00U)
#define IPI_BUFFER_PMU_BASE	(IPI_BUFFER_BASEADDR + 0xE00U)

#define IPI_BUFFER_TARGET_RPU_0_OFFSET	0x0U
#define IPI_BUFFER_TARGET_RPU_1_OFFSET	0x40U
#define IPI_BUFFER_TARGET_APU_OFFSET	0x80U
#define IPI_BUFFER_TARGET_PL_0_OFFSET	0xC0U
#define IPI_BUFFER_TARGET_PL_1_OFFSET	0x100U
#define IPI_BUFFER_TARGET_PL_2_OFFSET	0x140U
#define IPI_BUFFER_TARGET_PL_3_OFFSET	0x180U
#define IPI_BUFFER_TARGET_PMU_OFFSET	0x1C0U

#define IPI_BUFFER_MAX_WORDS	8

#define IPI_BUFFER_REQ_OFFSET	0x0U
#define IPI_BUFFER_RESP_OFFSET	0x20U

/* IPI Base Address */
#define IPI_BASEADDR		0XFF300000

/* APU's IPI registers */
#define IPI_APU_ISR		(IPI_BASEADDR + 0X00000010)
#define IPI_APU_IER		(IPI_BASEADDR + 0X00000018)
#define IPI_APU_IDR		(IPI_BASEADDR + 0X0000001C)
#define IPI_APU_IXR_PMU_0_MASK		(1 << 16)

#define IPI_TRIG_OFFSET		0
#define IPI_OBS_OFFSET		4

/* Power Management IPI interrupt number */
#define PM_INT_NUM		0
#define IPI_PMU_PM_INT_BASE	(IPI_PMU_0_TRIG + (PM_INT_NUM * 0x1000))
#define IPI_PMU_PM_INT_MASK	(IPI_APU_IXR_PMU_0_MASK << PM_INT_NUM)
#if (PM_INT_NUM < 0 || PM_INT_NUM > 3)
	#error PM_INT_NUM value out of range
#endif

#define IPI_APU_MASK		1U

DEFINE_BAKERY_LOCK(pm_secure_lock);

const struct pm_ipi apu_ipi = {
	.mask = IPI_APU_MASK,
	.base = IPI_BASEADDR,
	.buffer_base = IPI_BUFFER_APU_BASE,
};

/**
 * pm_ipi_init() - Initialize IPI peripheral for communication with PMU
 *
 * @return	On success, the initialization function must return 0.
 *		Any other return value will cause the framework to ignore
 *		the service
 *
 * Called from pm_setup initialization function
 */
int pm_ipi_init(void)
{
	bakery_lock_init(&pm_secure_lock);

	/* IPI Interrupts Clear & Disable */
	mmio_write_32(IPI_APU_ISR, 0xffffffff);
	mmio_write_32(IPI_APU_IDR, 0xffffffff);

	return 0;
}

/**
 * pm_ipi_wait() - wait for pmu to handle request
 * @proc	proc which is waiting for PMU to handle request
 */
static enum pm_ret_status pm_ipi_wait(const struct pm_proc *proc)
{
	int status;

	/* Wait until previous interrupt is handled by PMU */
	do {
		status = mmio_read_32(proc->ipi->base + IPI_OBS_OFFSET) &
					IPI_PMU_PM_INT_MASK;
		/* TODO: 1) Use timer to add delay between read attempts */
		/* TODO: 2) Return PM_RET_ERR_TIMEOUT if this times out */
	} while (status);

	return PM_RET_SUCCESS;
}

/**
 * pm_ipi_send_common() - Sends IPI request to the PMU
 * @proc	Pointer to the processor who is initiating request
 * @payload	API id and call arguments to be written in IPI buffer
 *
 * Send an IPI request to the power controller. Caller needs to hold
 * the 'pm_secure_lock' lock.
 *
 * @return	Returns status, either success or error+reason
 */
static enum pm_ret_status pm_ipi_send_common(const struct pm_proc *proc,
					     uint32_t payload[PAYLOAD_ARG_CNT])
{
	unsigned int offset = 0;
	uintptr_t buffer_base = proc->ipi->buffer_base +
					IPI_BUFFER_TARGET_PMU_OFFSET +
					IPI_BUFFER_REQ_OFFSET;

	/* Wait until previous interrupt is handled by PMU */
	pm_ipi_wait(proc);

	/* Write payload into IPI buffer */
	for (size_t i = 0; i < PAYLOAD_ARG_CNT; i++) {
		mmio_write_32(buffer_base + offset, payload[i]);
		offset += PAYLOAD_ARG_SIZE;
	}
	/* Generate IPI to PMU */
	mmio_write_32(proc->ipi->base + IPI_TRIG_OFFSET, IPI_PMU_PM_INT_MASK);

	return PM_RET_SUCCESS;
}

/**
 * pm_ipi_send() - Sends IPI request to the PMU
 * @proc	Pointer to the processor who is initiating request
 * @payload	API id and call arguments to be written in IPI buffer
 *
 * Send an IPI request to the power controller.
 *
 * @return	Returns status, either success or error+reason
 */
enum pm_ret_status pm_ipi_send(const struct pm_proc *proc,
			       uint32_t payload[PAYLOAD_ARG_CNT])
{
	enum pm_ret_status ret;

	bakery_lock_get(&pm_secure_lock);

	ret = pm_ipi_send_common(proc, payload);

	bakery_lock_release(&pm_secure_lock);

	return ret;
}


/**
 * pm_ipi_buff_read() - Reads IPI response after PMU has handled interrupt
 * @proc	Pointer to the processor who is waiting and reading response
 * @value	Used to return value from IPI buffer element (optional)
 * @count	Number of values to return in @value
 *
 * @return	Returns status, either success or error+reason
 */
static enum pm_ret_status pm_ipi_buff_read(const struct pm_proc *proc,
					   unsigned int *value, size_t count)
{
	size_t i;
	uintptr_t buffer_base = proc->ipi->buffer_base +
				IPI_BUFFER_TARGET_PMU_OFFSET +
				IPI_BUFFER_RESP_OFFSET;

	pm_ipi_wait(proc);

	/*
	 * Read response from IPI buffer
	 * buf-0: success or error+reason
	 * buf-1: value
	 * buf-2: unused
	 * buf-3: unused
	 */
	for (i = 1; i <= count; i++) {
		*value = mmio_read_32(buffer_base + (i * PAYLOAD_ARG_SIZE));
		value++;
	}

	return mmio_read_32(buffer_base);
}

/**
 * pm_ipi_buff_read_callb() - Reads IPI response after PMU has handled interrupt
 * @value	Used to return value from IPI buffer element (optional)
 * @count	Number of values to return in @value
 *
 * @return	Returns status, either success or error+reason
 */
void pm_ipi_buff_read_callb(unsigned int *value, size_t count)
{
	size_t i;
	uintptr_t buffer_base = IPI_BUFFER_PMU_BASE +
				IPI_BUFFER_TARGET_APU_OFFSET +
				IPI_BUFFER_REQ_OFFSET;

	if (count > IPI_BUFFER_MAX_WORDS)
		count = IPI_BUFFER_MAX_WORDS;

	for (i = 0; i <= count; i++) {
		*value = mmio_read_32(buffer_base + (i * PAYLOAD_ARG_SIZE));
		value++;
	}
}

/**
 * pm_ipi_send_sync() - Sends IPI request to the PMU
 * @proc	Pointer to the processor who is initiating request
 * @payload	API id and call arguments to be written in IPI buffer
 * @value	Used to return value from IPI buffer element (optional)
 * @count	Number of values to return in @value
 *
 * Send an IPI request to the power controller and wait for it to be handled.
 *
 * @return	Returns status, either success or error+reason and, optionally,
 *		@value
 */
enum pm_ret_status pm_ipi_send_sync(const struct pm_proc *proc,
				    uint32_t payload[PAYLOAD_ARG_CNT],
				    unsigned int *value, size_t count)
{
	enum pm_ret_status ret;

	bakery_lock_get(&pm_secure_lock);

	ret = pm_ipi_send_common(proc, payload);
	if (ret != PM_RET_SUCCESS)
		goto unlock;

	ret = pm_ipi_buff_read(proc, value, count);

unlock:
	bakery_lock_release(&pm_secure_lock);

	return ret;
}

void pm_ipi_irq_enable(void)
{
	mmio_write_32(IPI_APU_IER, IPI_APU_IXR_PMU_0_MASK);
}

void pm_ipi_irq_disable(void)
{
	mmio_write_32(IPI_APU_IDR, IPI_APU_IXR_PMU_0_MASK);
}

void pm_ipi_irq_clear(void)
{
	mmio_write_32(IPI_APU_ISR, IPI_APU_IXR_PMU_0_MASK);
}