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// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2019 MediaTek Inc.
#include <asm/barrier.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/time64.h>
#include <linux/remoteproc/mtk_scp.h>
#include "mtk_common.h"
#define SCP_TIMEOUT_US (2000 * USEC_PER_MSEC)
/**
* scp_ipi_register() - register an ipi function
*
* @scp: mtk_scp structure
* @id: IPI ID
* @handler: IPI handler
* @priv: private data for IPI handler
*
* Register an ipi function to receive ipi interrupt from SCP.
*
* Return: 0 if ipi registers successfully, -error on error.
*/
int scp_ipi_register(struct mtk_scp *scp,
u32 id,
scp_ipi_handler_t handler,
void *priv)
{
if (!scp)
return -EPROBE_DEFER;
if (WARN_ON(id >= SCP_IPI_MAX) || WARN_ON(handler == NULL))
return -EINVAL;
scp_ipi_lock(scp, id);
scp->ipi_desc[id].handler = handler;
scp->ipi_desc[id].priv = priv;
scp_ipi_unlock(scp, id);
return 0;
}
EXPORT_SYMBOL_GPL(scp_ipi_register);
/**
* scp_ipi_unregister() - unregister an ipi function
*
* @scp: mtk_scp structure
* @id: IPI ID
*
* Unregister an ipi function to receive ipi interrupt from SCP.
*/
void scp_ipi_unregister(struct mtk_scp *scp, u32 id)
{
if (!scp)
return;
if (WARN_ON(id >= SCP_IPI_MAX))
return;
scp_ipi_lock(scp, id);
scp->ipi_desc[id].handler = NULL;
scp->ipi_desc[id].priv = NULL;
scp_ipi_unlock(scp, id);
}
EXPORT_SYMBOL_GPL(scp_ipi_unregister);
/*
* scp_memcpy_aligned() - Copy src to dst, where dst is in SCP SRAM region.
*
* @dst: Pointer to the destination buffer, should be in SCP SRAM region.
* @src: Pointer to the source buffer.
* @len: Length of the source buffer to be copied.
*
* Since AP access of SCP SRAM don't support byte write, this always write a
* full word at a time, and may cause some extra bytes to be written at the
* beginning & ending of dst.
*/
void scp_memcpy_aligned(void __iomem *dst, const void *src, unsigned int len)
{
void __iomem *ptr;
u32 val;
unsigned int i = 0, remain;
if (!IS_ALIGNED((unsigned long)dst, 4)) {
ptr = (void __iomem *)ALIGN_DOWN((unsigned long)dst, 4);
i = 4 - (dst - ptr);
val = readl_relaxed(ptr);
memcpy((u8 *)&val + (4 - i), src, i);
writel_relaxed(val, ptr);
}
__iowrite32_copy(dst + i, src + i, (len - i) / 4);
remain = (len - i) % 4;
if (remain > 0) {
val = readl_relaxed(dst + len - remain);
memcpy(&val, src + len - remain, remain);
writel_relaxed(val, dst + len - remain);
}
}
EXPORT_SYMBOL_GPL(scp_memcpy_aligned);
/**
* scp_ipi_lock() - Lock before operations of an IPI ID
*
* @scp: mtk_scp structure
* @id: IPI ID
*
* Note: This should not be used by drivers other than mtk_scp.
*/
void scp_ipi_lock(struct mtk_scp *scp, u32 id)
{
if (WARN_ON(id >= SCP_IPI_MAX))
return;
mutex_lock(&scp->ipi_desc[id].lock);
}
EXPORT_SYMBOL_GPL(scp_ipi_lock);
/**
* scp_ipi_lock() - Unlock after operations of an IPI ID
*
* @scp: mtk_scp structure
* @id: IPI ID
*
* Note: This should not be used by drivers other than mtk_scp.
*/
void scp_ipi_unlock(struct mtk_scp *scp, u32 id)
{
if (WARN_ON(id >= SCP_IPI_MAX))
return;
mutex_unlock(&scp->ipi_desc[id].lock);
}
EXPORT_SYMBOL_GPL(scp_ipi_unlock);
/**
* scp_ipi_send() - send data from AP to scp.
*
* @scp: mtk_scp structure
* @id: IPI ID
* @buf: the data buffer
* @len: the data buffer length
* @wait: number of msecs to wait for ack. 0 to skip waiting.
*
* This function is thread-safe. When this function returns,
* SCP has received the data and starts the processing.
* When the processing completes, IPI handler registered
* by scp_ipi_register will be called in interrupt context.
*
* Return: 0 if sending data successfully, -error on error.
**/
int scp_ipi_send(struct mtk_scp *scp, u32 id, void *buf, unsigned int len,
unsigned int wait)
{
struct mtk_share_obj __iomem *send_obj = scp->send_buf;
u32 val;
int ret;
if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) ||
WARN_ON(id == SCP_IPI_NS_SERVICE) ||
WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf))
return -EINVAL;
ret = clk_prepare_enable(scp->clk);
if (ret) {
dev_err(scp->dev, "failed to enable clock\n");
return ret;
}
mutex_lock(&scp->send_lock);
/* Wait until SCP receives the last command */
ret = readl_poll_timeout_atomic(scp->reg_base + scp->data->host_to_scp_reg,
val, !val, 0, SCP_TIMEOUT_US);
if (ret) {
dev_err(scp->dev, "%s: IPI timeout!\n", __func__);
goto unlock_mutex;
}
scp_memcpy_aligned(send_obj->share_buf, buf, len);
writel(len, &send_obj->len);
writel(id, &send_obj->id);
scp->ipi_id_ack[id] = false;
/* send the command to SCP */
writel(scp->data->host_to_scp_int_bit,
scp->reg_base + scp->data->host_to_scp_reg);
if (wait) {
/* wait for SCP's ACK */
ret = wait_event_timeout(scp->ack_wq,
scp->ipi_id_ack[id],
msecs_to_jiffies(wait));
scp->ipi_id_ack[id] = false;
if (WARN(!ret, "scp ipi %d ack time out !", id))
ret = -EIO;
else
ret = 0;
}
unlock_mutex:
mutex_unlock(&scp->send_lock);
clk_disable_unprepare(scp->clk);
return ret;
}
EXPORT_SYMBOL_GPL(scp_ipi_send);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MediaTek scp IPI interface");
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