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1// SPDX-License-Identifier: GPL-2.02//3// Copyright (c) 2019 MediaTek Inc.4 5#include <asm/barrier.h>6#include <linux/clk.h>7#include <linux/err.h>8#include <linux/io.h>9#include <linux/iopoll.h>10#include <linux/kernel.h>11#include <linux/module.h>12#include <linux/platform_device.h>13#include <linux/time64.h>14#include <linux/remoteproc/mtk_scp.h>15 16#include "mtk_common.h"17 18#define SCP_TIMEOUT_US (2000 * USEC_PER_MSEC)19 20/**21 * scp_ipi_register() - register an ipi function22 *23 * @scp: mtk_scp structure24 * @id: IPI ID25 * @handler: IPI handler26 * @priv: private data for IPI handler27 *28 * Register an ipi function to receive ipi interrupt from SCP.29 *30 * Return: 0 if ipi registers successfully, -error on error.31 */32int scp_ipi_register(struct mtk_scp *scp,33 u32 id,34 scp_ipi_handler_t handler,35 void *priv)36{37 if (!scp)38 return -EPROBE_DEFER;39 40 if (WARN_ON(id >= SCP_IPI_MAX) || WARN_ON(handler == NULL))41 return -EINVAL;42 43 scp_ipi_lock(scp, id);44 scp->ipi_desc[id].handler = handler;45 scp->ipi_desc[id].priv = priv;46 scp_ipi_unlock(scp, id);47 48 return 0;49}50EXPORT_SYMBOL_GPL(scp_ipi_register);51 52/**53 * scp_ipi_unregister() - unregister an ipi function54 *55 * @scp: mtk_scp structure56 * @id: IPI ID57 *58 * Unregister an ipi function to receive ipi interrupt from SCP.59 */60void scp_ipi_unregister(struct mtk_scp *scp, u32 id)61{62 if (!scp)63 return;64 65 if (WARN_ON(id >= SCP_IPI_MAX))66 return;67 68 scp_ipi_lock(scp, id);69 scp->ipi_desc[id].handler = NULL;70 scp->ipi_desc[id].priv = NULL;71 scp_ipi_unlock(scp, id);72}73EXPORT_SYMBOL_GPL(scp_ipi_unregister);74 75/*76 * scp_memcpy_aligned() - Copy src to dst, where dst is in SCP SRAM region.77 *78 * @dst: Pointer to the destination buffer, should be in SCP SRAM region.79 * @src: Pointer to the source buffer.80 * @len: Length of the source buffer to be copied.81 *82 * Since AP access of SCP SRAM don't support byte write, this always write a83 * full word at a time, and may cause some extra bytes to be written at the84 * beginning & ending of dst.85 */86void scp_memcpy_aligned(void __iomem *dst, const void *src, unsigned int len)87{88 void __iomem *ptr;89 u32 val;90 unsigned int i = 0, remain;91 92 if (!IS_ALIGNED((unsigned long)dst, 4)) {93 ptr = (void __iomem *)ALIGN_DOWN((unsigned long)dst, 4);94 i = 4 - (dst - ptr);95 val = readl_relaxed(ptr);96 memcpy((u8 *)&val + (4 - i), src, i);97 writel_relaxed(val, ptr);98 }99 100 __iowrite32_copy(dst + i, src + i, (len - i) / 4);101 remain = (len - i) % 4;102 103 if (remain > 0) {104 val = readl_relaxed(dst + len - remain);105 memcpy(&val, src + len - remain, remain);106 writel_relaxed(val, dst + len - remain);107 }108}109EXPORT_SYMBOL_GPL(scp_memcpy_aligned);110 111/**112 * scp_ipi_lock() - Lock before operations of an IPI ID113 *114 * @scp: mtk_scp structure115 * @id: IPI ID116 *117 * Note: This should not be used by drivers other than mtk_scp.118 */119void scp_ipi_lock(struct mtk_scp *scp, u32 id)120{121 if (WARN_ON(id >= SCP_IPI_MAX))122 return;123 mutex_lock(&scp->ipi_desc[id].lock);124}125EXPORT_SYMBOL_GPL(scp_ipi_lock);126 127/**128 * scp_ipi_unlock() - Unlock after operations of an IPI ID129 *130 * @scp: mtk_scp structure131 * @id: IPI ID132 *133 * Note: This should not be used by drivers other than mtk_scp.134 */135void scp_ipi_unlock(struct mtk_scp *scp, u32 id)136{137 if (WARN_ON(id >= SCP_IPI_MAX))138 return;139 mutex_unlock(&scp->ipi_desc[id].lock);140}141EXPORT_SYMBOL_GPL(scp_ipi_unlock);142 143/**144 * scp_ipi_send() - send data from AP to scp.145 *146 * @scp: mtk_scp structure147 * @id: IPI ID148 * @buf: the data buffer149 * @len: the data buffer length150 * @wait: number of msecs to wait for ack. 0 to skip waiting.151 *152 * This function is thread-safe. When this function returns,153 * SCP has received the data and starts the processing.154 * When the processing completes, IPI handler registered155 * by scp_ipi_register will be called in interrupt context.156 *157 * Return: 0 if sending data successfully, -error on error.158 **/159int scp_ipi_send(struct mtk_scp *scp, u32 id, void *buf, unsigned int len,160 unsigned int wait)161{162 struct mtk_share_obj __iomem *send_obj = scp->send_buf;163 u32 val;164 int ret;165 const struct mtk_scp_sizes_data *scp_sizes;166 167 scp_sizes = scp->data->scp_sizes;168 169 if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) ||170 WARN_ON(id == SCP_IPI_NS_SERVICE) ||171 WARN_ON(len > scp_sizes->ipi_share_buffer_size) || WARN_ON(!buf))172 return -EINVAL;173 174 ret = clk_prepare_enable(scp->clk);175 if (ret) {176 dev_err(scp->dev, "failed to enable clock\n");177 return ret;178 }179 180 mutex_lock(&scp->send_lock);181 182 /* Wait until SCP receives the last command */183 ret = readl_poll_timeout_atomic(scp->cluster->reg_base + scp->data->host_to_scp_reg,184 val, !val, 0, SCP_TIMEOUT_US);185 if (ret) {186 dev_err(scp->dev, "%s: IPI timeout!\n", __func__);187 goto unlock_mutex;188 }189 190 scp_memcpy_aligned(&send_obj->share_buf, buf, len);191 192 writel(len, &send_obj->len);193 writel(id, &send_obj->id);194 195 scp->ipi_id_ack[id] = false;196 /* send the command to SCP */197 writel(scp->data->host_to_scp_int_bit,198 scp->cluster->reg_base + scp->data->host_to_scp_reg);199 200 if (wait) {201 /* wait for SCP's ACK */202 ret = wait_event_timeout(scp->ack_wq,203 scp->ipi_id_ack[id],204 msecs_to_jiffies(wait));205 scp->ipi_id_ack[id] = false;206 if (WARN(!ret, "scp ipi %d ack time out !", id))207 ret = -EIO;208 else209 ret = 0;210 }211 212unlock_mutex:213 mutex_unlock(&scp->send_lock);214 clk_disable_unprepare(scp->clk);215 216 return ret;217}218EXPORT_SYMBOL_GPL(scp_ipi_send);219 220MODULE_LICENSE("GPL v2");221MODULE_DESCRIPTION("MediaTek scp IPI interface");222