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![Pi-Hsun Shih](/assets/img/avatar_default.png)
Add a simple rpmsg support for mt8183 SCP, that use IPI / IPC directly. Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org> Link: https://lore.kernel.org/r/20191112110330.179649-4-pihsun@chromium.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
219 lines
5.3 KiB
C
219 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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//
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// Copyright (c) 2019 MediaTek Inc.
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#include <asm/barrier.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/remoteproc/mtk_scp.h>
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#include "mtk_common.h"
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/**
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* scp_ipi_register() - register an ipi function
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*
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* @scp: mtk_scp structure
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* @id: IPI ID
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* @handler: IPI handler
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* @priv: private data for IPI handler
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*
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* Register an ipi function to receive ipi interrupt from SCP.
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*
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* Returns 0 if ipi registers successfully, -error on error.
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*/
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int scp_ipi_register(struct mtk_scp *scp,
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u32 id,
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scp_ipi_handler_t handler,
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void *priv)
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{
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if (!scp) {
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dev_err(scp->dev, "scp device is not ready\n");
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return -EPROBE_DEFER;
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}
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if (WARN_ON(id >= SCP_IPI_MAX) || WARN_ON(handler == NULL))
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return -EINVAL;
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scp_ipi_lock(scp, id);
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scp->ipi_desc[id].handler = handler;
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scp->ipi_desc[id].priv = priv;
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scp_ipi_unlock(scp, id);
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return 0;
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}
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EXPORT_SYMBOL_GPL(scp_ipi_register);
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/**
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* scp_ipi_unregister() - unregister an ipi function
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*
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* @scp: mtk_scp structure
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* @id: IPI ID
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*
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* Unregister an ipi function to receive ipi interrupt from SCP.
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*/
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void scp_ipi_unregister(struct mtk_scp *scp, u32 id)
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{
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if (!scp)
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return;
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if (WARN_ON(id >= SCP_IPI_MAX))
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return;
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scp_ipi_lock(scp, id);
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scp->ipi_desc[id].handler = NULL;
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scp->ipi_desc[id].priv = NULL;
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scp_ipi_unlock(scp, id);
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}
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EXPORT_SYMBOL_GPL(scp_ipi_unregister);
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/*
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* scp_memcpy_aligned() - Copy src to dst, where dst is in SCP SRAM region.
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*
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* @dst: Pointer to the destination buffer, should be in SCP SRAM region.
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* @src: Pointer to the source buffer.
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* @len: Length of the source buffer to be copied.
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*
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* Since AP access of SCP SRAM don't support byte write, this always write a
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* full word at a time, and may cause some extra bytes to be written at the
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* beginning & ending of dst.
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*/
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void scp_memcpy_aligned(void __iomem *dst, const void *src, unsigned int len)
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{
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void __iomem *ptr;
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u32 val;
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unsigned int i = 0, remain;
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if (!IS_ALIGNED((unsigned long)dst, 4)) {
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ptr = (void __iomem *)ALIGN_DOWN((unsigned long)dst, 4);
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i = 4 - (dst - ptr);
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val = readl_relaxed(ptr);
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memcpy((u8 *)&val + (4 - i), src, i);
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writel_relaxed(val, ptr);
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}
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__iowrite32_copy(dst + i, src + i, (len - i) / 4);
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remain = (len - i) % 4;
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if (remain > 0) {
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val = readl_relaxed(dst + len - remain);
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memcpy(&val, src + len - remain, remain);
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writel_relaxed(val, dst + len - remain);
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}
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}
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EXPORT_SYMBOL_GPL(scp_memcpy_aligned);
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/**
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* scp_ipi_lock() - Lock before operations of an IPI ID
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*
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* @scp: mtk_scp structure
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* @id: IPI ID
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*
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* Note: This should not be used by drivers other than mtk_scp.
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*/
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void scp_ipi_lock(struct mtk_scp *scp, u32 id)
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{
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if (WARN_ON(id >= SCP_IPI_MAX))
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return;
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mutex_lock(&scp->ipi_desc[id].lock);
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}
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EXPORT_SYMBOL_GPL(scp_ipi_lock);
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/**
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* scp_ipi_lock() - Unlock after operations of an IPI ID
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*
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* @scp: mtk_scp structure
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* @id: IPI ID
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*
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* Note: This should not be used by drivers other than mtk_scp.
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*/
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void scp_ipi_unlock(struct mtk_scp *scp, u32 id)
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{
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if (WARN_ON(id >= SCP_IPI_MAX))
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return;
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mutex_unlock(&scp->ipi_desc[id].lock);
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}
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EXPORT_SYMBOL_GPL(scp_ipi_unlock);
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/**
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* scp_ipi_send() - send data from AP to scp.
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*
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* @scp: mtk_scp structure
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* @id: IPI ID
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* @buf: the data buffer
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* @len: the data buffer length
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* @wait: number of msecs to wait for ack. 0 to skip waiting.
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*
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* This function is thread-safe. When this function returns,
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* SCP has received the data and starts the processing.
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* When the processing completes, IPI handler registered
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* by scp_ipi_register will be called in interrupt context.
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*
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* Returns 0 if sending data successfully, -error on error.
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**/
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int scp_ipi_send(struct mtk_scp *scp, u32 id, void *buf, unsigned int len,
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unsigned int wait)
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{
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struct mtk_share_obj __iomem *send_obj = scp->send_buf;
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unsigned long timeout;
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int ret;
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if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) ||
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WARN_ON(id == SCP_IPI_NS_SERVICE) ||
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WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf))
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return -EINVAL;
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mutex_lock(&scp->send_lock);
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ret = clk_prepare_enable(scp->clk);
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if (ret) {
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dev_err(scp->dev, "failed to enable clock\n");
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goto unlock_mutex;
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}
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/* Wait until SCP receives the last command */
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timeout = jiffies + msecs_to_jiffies(2000);
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do {
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if (time_after(jiffies, timeout)) {
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dev_err(scp->dev, "%s: IPI timeout!\n", __func__);
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ret = -ETIMEDOUT;
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goto clock_disable;
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}
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} while (readl(scp->reg_base + MT8183_HOST_TO_SCP));
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scp_memcpy_aligned(send_obj->share_buf, buf, len);
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writel(len, &send_obj->len);
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writel(id, &send_obj->id);
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scp->ipi_id_ack[id] = false;
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/* send the command to SCP */
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writel(MT8183_HOST_IPC_INT_BIT, scp->reg_base + MT8183_HOST_TO_SCP);
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if (wait) {
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/* wait for SCP's ACK */
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timeout = msecs_to_jiffies(wait);
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ret = wait_event_timeout(scp->ack_wq,
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scp->ipi_id_ack[id],
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timeout);
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scp->ipi_id_ack[id] = false;
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if (WARN(!ret, "scp ipi %d ack time out !", id))
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ret = -EIO;
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else
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ret = 0;
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}
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clock_disable:
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clk_disable_unprepare(scp->clk);
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unlock_mutex:
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mutex_unlock(&scp->send_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(scp_ipi_send);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("MediaTek scp IPI interface");
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