[PATCH v7 2/7] remoteproc/mediatek: add SCP support for mt8183

Peter Shih
2019-03-27T05:15:13Z

From: Erin Lo <erin.lo@mediatek.com>

Provide a basic driver to control Cortex M4 co-processor

Signed-off-by: Erin Lo <erin.lo@mediatek.com>
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
Changes from v6:
- No change.

Changes from v5:
- Changed some space to tab.

Changes from v4:
- Rename most function from mtk_scp_* to scp_*.
- Change the irq to threaded handler.
- Load ELF file instead of plain binary file as firmware by default
(Squashed patch 6 in v4 into this patch).

Changes from v3:
- Fix some issue found by checkpatch.
- Make writes aligned in scp_ipi_send.

Changes from v2:
- Squash patch 3 from v2 (separate the ipi interface) into this patch.
- Remove unused name argument from scp_ipi_register.
- Add scp_ipi_unregister for proper cleanup.
- Move IPI ids in sync with firmware.
- Add mb() in proper place, and correctly clear the run->signaled.

Changes from v1:
- Extract functions and rename variables in mtk_scp.c.
---
drivers/remoteproc/Kconfig | 9 +
drivers/remoteproc/Makefile | 1 +
drivers/remoteproc/mtk_common.h | 75 ++++
drivers/remoteproc/mtk_scp.c | 496 ++++++++++++++++++++++++++
drivers/remoteproc/mtk_scp_ipi.c | 162 +++++++++
include/linux/platform_data/mtk_scp.h | 135 +++++++
6 files changed, 878 insertions(+)
create mode 100644 drivers/remoteproc/mtk_common.h
create mode 100644 drivers/remoteproc/mtk_scp.c
create mode 100644 drivers/remoteproc/mtk_scp_ipi.c
create mode 100644 include/linux/platform_data/mtk_scp.h

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index f0abd2608044..92bd20d6b9cd 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -22,6 +22,15 @@ config IMX_REMOTEPROC

It's safe to say N here.

+config MTK_SCP
+ tristate "Mediatek SCP support"
+ depends on ARCH_MEDIATEK
+ help
+ Say y here to support Mediatek's System Companion Processor (SCP) via
+ the remote processor framework.
+
+ It's safe to say N here.
+
config OMAP_REMOTEPROC
tristate "OMAP remoteproc support"
depends on ARCH_OMAP4 || SOC_OMAP5
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index ce5d061e92be..16b3e5e7a81c 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -10,6 +10,7 @@ remoteproc-y += remoteproc_sysfs.o
remoteproc-y += remoteproc_virtio.o
remoteproc-y += remoteproc_elf_loader.o
obj-$(CONFIG_IMX_REMOTEPROC) += imx_rproc.o
+obj-$(CONFIG_MTK_SCP) += mtk_scp.o mtk_scp_ipi.o
obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o
obj-$(CONFIG_WKUP_M3_RPROC) += wkup_m3_rproc.o
obj-$(CONFIG_DA8XX_REMOTEPROC) += da8xx_remoteproc.o
diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
new file mode 100644
index 000000000000..7504ae1bc0ef
--- /dev/null
+++ b/drivers/remoteproc/mtk_common.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018 MediaTek Inc.
+ */
+
+#ifndef __RPROC_MTK_COMMON_H
+#define __RPROC_MTK_COMMON_H
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/remoteproc.h>
+
+#define MT8183_SW_RSTN 0x0
+#define MT8183_SW_RSTN_BIT BIT(0)
+#define MT8183_SCP_TO_HOST 0x1C
+#define MT8183_SCP_IPC_INT_BIT BIT(0)
+#define MT8183_SCP_WDT_INT_BIT BIT(8)
+#define MT8183_HOST_TO_SCP 0x28
+#define MT8183_HOST_IPC_INT_BIT BIT(0)
+#define MT8183_SCP_SRAM_PDN 0x402C
+
+#define SCP_FW_VER_LEN 32
+
+struct scp_run {
+ u32 signaled;
+ s8 fw_ver[SCP_FW_VER_LEN];
+ u32 dec_capability;
+ u32 enc_capability;
+ wait_queue_head_t wq;
+};
+
+struct scp_ipi_desc {
+ scp_ipi_handler_t handler;
+ void *priv;
+};
+
+struct mtk_scp {
+ struct device *dev;
+ struct rproc *rproc;
+ struct clk *clk;
+ void __iomem *reg_base;
+ void __iomem *sram_base;
+ size_t sram_size;
+
+ struct share_obj *recv_buf;
+ struct share_obj *send_buf;
+ struct scp_run run;
+ struct mutex lock; /* for protecting mtk_scp data structure */
+ struct scp_ipi_desc ipi_desc[SCP_IPI_MAX];
+ bool ipi_id_ack[SCP_IPI_MAX];
+ wait_queue_head_t ack_wq;
+
+ void __iomem *cpu_addr;
+ phys_addr_t phys_addr;
+ size_t dram_size;
+};
+
+/**
+ * struct share_obj - SRAM buffer shared with
+ * AP and SCP
+ *
+ * @id: IPI id
+ * @len: share buffer length
+ * @share_buf: share buffer data
+ */
+struct share_obj {
+ s32 id;
+ u32 len;
+ u8 share_buf[288];
+};
+
+void scp_memcpy_aligned(void *dst, const void *src, unsigned int len);
+
+#endif
diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
new file mode 100644
index 000000000000..a84d69ae6c53
--- /dev/null
+++ b/drivers/remoteproc/mtk_scp.c
@@ -0,0 +1,496 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2018 MediaTek Inc.
+
+#include <asm/barrier.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_data/mtk_scp.h>
+#include <linux/platform_device.h>
+#include <linux/remoteproc.h>
+
+#include "mtk_common.h"
+#include "remoteproc_internal.h"
+
+#define MAX_CODE_SIZE 0x500000
+#define SCP_FW_BASE 0x800
+
+struct platform_device *scp_get_pdev(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *scp_node;
+ struct platform_device *scp_pdev;
+
+ scp_node = of_parse_phandle(dev->of_node, "mediatek,scp", 0);
+ if (!scp_node) {
+ dev_err(dev, "can't get SCP node\n");
+ return NULL;
+ }
+
+ scp_pdev = of_find_device_by_node(scp_node);
+ if (WARN_ON(!scp_pdev)) {
+ dev_err(dev, "SCP pdev failed\n");
+ of_node_put(scp_node);
+ return NULL;
+ }
+
+ return scp_pdev;
+}
+EXPORT_SYMBOL_GPL(scp_get_pdev);
+
+static void scp_wdt_handler(struct mtk_scp *scp)
+{
+ rproc_report_crash(scp->rproc, RPROC_WATCHDOG);
+}
+
+static void scp_init_ipi_handler(void *data, unsigned int len, void *priv)
+{
+ struct mtk_scp *scp = (struct mtk_scp *)priv;
+ struct scp_run *run = (struct scp_run *)data;
+
+ scp->run.signaled = run->signaled;
+ strncpy(scp->run.fw_ver, run->fw_ver, SCP_FW_VER_LEN);
+ scp->run.dec_capability = run->dec_capability;
+ scp->run.enc_capability = run->enc_capability;
+ wake_up_interruptible(&scp->run.wq);
+}
+
+static void scp_ipi_handler(struct mtk_scp *scp)
+{
+ struct share_obj *rcv_obj = scp->recv_buf;
+ struct scp_ipi_desc *ipi_desc = scp->ipi_desc;
+ u8 tmp_data[288];
+
+ if (rcv_obj->id >= SCP_IPI_MAX || !ipi_desc[rcv_obj->id].handler) {
+ dev_err(scp->dev, "No such ipi id = %d\n", rcv_obj->id);
+ return;
+ }
+
+ memcpy_fromio(tmp_data, &rcv_obj->share_buf, rcv_obj->len);
+ ipi_desc[rcv_obj->id].handler(tmp_data,
+ rcv_obj->len,
+ ipi_desc[rcv_obj->id].priv);
+ scp->ipi_id_ack[rcv_obj->id] = true;
+ wake_up(&scp->ack_wq);
+}
+
+static int scp_ipi_init(struct mtk_scp *scp)
+{
+ size_t send_offset = SCP_FW_BASE - sizeof(struct share_obj);
+ size_t recv_offset = send_offset - sizeof(struct share_obj);
+
+ /* Disable SCP to host interrupt */
+ writel(MT8183_SCP_IPC_INT_BIT, scp->reg_base + MT8183_SCP_TO_HOST);
+
+ /* shared buffer initialization */
+ scp->recv_buf = (__force struct share_obj *)(scp->sram_base +
+ recv_offset);
+ scp->send_buf = (__force struct share_obj *)(scp->sram_base +
+ send_offset);
+ memset_io(scp->recv_buf, 0, sizeof(scp->recv_buf));
+ memset_io(scp->send_buf, 0, sizeof(scp->send_buf));
+
+ return 0;
+}
+
+static void scp_reset_assert(const struct mtk_scp *scp)
+{
+ u32 val;
+
+ val = readl(scp->reg_base + MT8183_SW_RSTN);
+ val &= ~MT8183_SW_RSTN_BIT;
+ writel(val, scp->reg_base + MT8183_SW_RSTN);
+}
+
+static void scp_reset_deassert(const struct mtk_scp *scp)
+{
+ u32 val;
+
+ val = readl(scp->reg_base + MT8183_SW_RSTN);
+ val |= MT8183_SW_RSTN_BIT;
+ writel(val, scp->reg_base + MT8183_SW_RSTN);
+}
+
+static irqreturn_t scp_irq_handler(int irq, void *priv)
+{
+ struct mtk_scp *scp = priv;
+ u32 scp_to_host;
+
+ scp_to_host = readl(scp->reg_base + MT8183_SCP_TO_HOST);
+ if (scp_to_host & MT8183_SCP_IPC_INT_BIT) {
+ scp_ipi_handler(scp);
+ } else {
+ dev_err(scp->dev, "SCP watchdog timeout! 0x%x", scp_to_host);
+ scp_wdt_handler(scp);
+ }
+
+ /*
+ * Ensure that all writes to SRAM are committed before another
+ * interrupt.
+ */
+ mb();
+ /* SCP won't send another interrupt until we set SCP_TO_HOST to 0. */
+ writel(MT8183_SCP_IPC_INT_BIT | MT8183_SCP_WDT_INT_BIT,
+ scp->reg_base + MT8183_SCP_TO_HOST);
+
+ return IRQ_HANDLED;
+}
+
+int scp_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
+{
+ struct device *dev = &rproc->dev;
+ struct elf32_hdr *ehdr;
+ struct elf32_phdr *phdr;
+ int i, ret = 0;
+ const u8 *elf_data = fw->data;
+
+ ehdr = (struct elf32_hdr *)elf_data;
+ phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
+
+ /* go through the available ELF segments */
+ for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
+ u32 da = phdr->p_paddr;
+ u32 memsz = phdr->p_memsz;
+ u32 filesz = phdr->p_filesz;
+ u32 offset = phdr->p_offset;
+ void __iomem *ptr;
+
+ if (phdr->p_type != PT_LOAD)
+ continue;
+
+ dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
+ phdr->p_type, da, memsz, filesz);
+
+ if (filesz > memsz) {
+ dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
+ filesz, memsz);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (offset + filesz > fw->size) {
+ dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
+ offset + filesz, fw->size);
+ ret = -EINVAL;
+ break;
+ }
+
+ /* grab the kernel address for this device address */
+ ptr = rproc_da_to_va(rproc, da, memsz);
+ if (!ptr) {
+ dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
+ ret = -EINVAL;
+ break;
+ }
+
+ /* put the segment where the remote processor expects it */
+ if (phdr->p_filesz)
+ scp_memcpy_aligned(ptr, elf_data + phdr->p_offset,
+ filesz);
+ }
+
+ return ret;
+}
+
+static int scp_load(struct rproc *rproc, const struct firmware *fw)
+{
+ const struct mtk_scp *scp = rproc->priv;
+ struct device *dev = scp->dev;
+ int ret;
+
+ /* Hold SCP in reset while loading FW. */
+ scp_reset_assert(scp);
+
+ ret = clk_prepare_enable(scp->clk);
+ if (ret) {
+ scp_reset_deassert(scp);
+ dev_err(dev, "failed to enable clocks\n");
+ return ret;
+ }
+
+ /* Turn on the power of SCP's SRAM before using it. */
+ writel(0x0, scp->reg_base + MT8183_SCP_SRAM_PDN);
+
+ return scp_elf_load_segments(rproc, fw);
+}
+
+static int scp_start(struct rproc *rproc)
+{
+ struct mtk_scp *scp = (struct mtk_scp *)rproc->priv;
+ struct device *dev = scp->dev;
+ struct scp_run *run;
+ int ret;
+
+ ret = clk_prepare_enable(scp->clk);
+ if (ret) {
+ dev_err(dev, "failed to enable clocks\n");
+ return ret;
+ }
+
+ run = &scp->run;
+ run->signaled = false;
+
+ scp_reset_deassert(scp);
+
+ ret = wait_event_interruptible_timeout(
+ run->wq,
+ run->signaled,
+ msecs_to_jiffies(2000));
+
+ if (ret == 0) {
+ dev_err(dev, "wait SCP initialization timeout!\n");
+ ret = -ETIME;
+ goto stop;
+ }
+ if (ret == -ERESTARTSYS) {
+ dev_err(dev, "wait SCP interrupted by a signal!\n");
+ goto stop;
+ }
+ dev_info(dev, "SCP is ready. FW version %s\n", run->fw_ver);
+
+ return 0;
+
+stop:
+ scp_reset_assert(scp);
+ clk_disable_unprepare(scp->clk);
+ return ret;
+}
+
+static void *scp_da_to_va(struct rproc *rproc, u64 da, int len)
+{
+ struct mtk_scp *scp = (struct mtk_scp *)rproc->priv;
+ int offset;
+
+ if (da < scp->sram_size) {
+ offset = da;
+ if (offset >= 0 && ((offset + len) < scp->sram_size))
+ return (__force void *)(scp->sram_base + offset);
+ } else if (da >= scp->sram_size &&
+ da < (scp->sram_size + MAX_CODE_SIZE)) {
+ offset = da - scp->sram_size;
+ if (offset >= 0 && (offset + len) < MAX_CODE_SIZE)
+ return scp->cpu_addr + offset;
+ } else {
+ offset = da - scp->phys_addr;
+ if (offset >= 0 &&
+ (offset + len) < (scp->dram_size - MAX_CODE_SIZE))
+ return scp->cpu_addr + offset;
+ }
+
+ return NULL;
+}
+
+static int scp_stop(struct rproc *rproc)
+{
+ struct mtk_scp *scp = (struct mtk_scp *)rproc->priv;
+
+ scp_reset_assert(scp);
+ clk_disable_unprepare(scp->clk);
+
+ return 0;
+}
+
+static const struct rproc_ops scp_ops = {
+ .start = scp_start,
+ .stop = scp_stop,
+ .load = scp_load,
+ .da_to_va = scp_da_to_va,
+};
+
+unsigned int scp_get_vdec_hw_capa(struct platform_device *pdev)
+{
+ struct mtk_scp *scp = platform_get_drvdata(pdev);
+
+ return scp->run.dec_capability;
+}
+EXPORT_SYMBOL_GPL(scp_get_vdec_hw_capa);
+
+unsigned int scp_get_venc_hw_capa(struct platform_device *pdev)
+{
+ struct mtk_scp *scp = platform_get_drvdata(pdev);
+
+ return scp->run.enc_capability;
+}
+EXPORT_SYMBOL_GPL(scp_get_venc_hw_capa);
+
+void *scp_mapping_dm_addr(struct platform_device *pdev, u32 mem_addr)
+{
+ struct mtk_scp *scp = platform_get_drvdata(pdev);
+ void *ptr;
+
+ ptr = scp_da_to_va(scp->rproc, mem_addr, 0);
+ if (!ptr)
+ return ERR_PTR(-EINVAL);
+
+ return ptr;
+}
+EXPORT_SYMBOL_GPL(scp_mapping_dm_addr);
+
+static int scp_map_memory_region(struct mtk_scp *scp)
+{
+ struct device_node *node;
+ struct resource r;
+ int ret;
+
+ node = of_parse_phandle(scp->dev->of_node, "memory-region", 0);
+ if (!node) {
+ dev_err(scp->dev, "no memory-region specified\n");
+ return -EINVAL;
+ }
+
+ ret = of_address_to_resource(node, 0, &r);
+ if (ret)
+ return ret;
+
+ scp->phys_addr = r.start;
+ scp->dram_size = resource_size(&r);
+ scp->cpu_addr =
+ devm_ioremap_wc(scp->dev, scp->phys_addr, scp->dram_size);
+
+ if (!scp->cpu_addr) {
+ dev_err(scp->dev, "unable to map memory region: %pa+%zx\n",
+ &r.start, scp->dram_size);
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+static int scp_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct mtk_scp *scp;
+ struct rproc *rproc;
+ struct resource *res;
+ char *fw_name = "scp.img";
+ int ret;
+
+ rproc = rproc_alloc(dev,
+ np->name,
+ &scp_ops,
+ fw_name,
+ sizeof(*scp));
+ if (!rproc) {
+ dev_err(dev, "unable to allocate remoteproc\n");
+ return -ENOMEM;
+ }
+
+ scp = (struct mtk_scp *)rproc->priv;
+ scp->rproc = rproc;
+ scp->dev = dev;
+ platform_set_drvdata(pdev, scp);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sram");
+ scp->sram_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR((__force void *)scp->sram_base)) {
+ dev_err(dev, "Failed to parse and map sram memory\n");
+ ret = PTR_ERR((__force void *)scp->sram_base);
+ goto free_rproc;
+ }
+ scp->sram_size = resource_size(res);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+ scp->reg_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR((__force void *)scp->reg_base)) {
+ dev_err(dev, "Failed to parse and map cfg memory\n");
+ ret = PTR_ERR((__force void *)scp->reg_base);
+ goto free_rproc;
+ }
+
+ ret = scp_map_memory_region(scp);
+ if (ret)
+ goto free_rproc;
+
+ scp->clk = devm_clk_get(dev, "main");
+ if (IS_ERR(scp->clk)) {
+ dev_err(dev, "Failed to get clock\n");
+ ret = PTR_ERR(scp->clk);
+ goto free_rproc;
+ }
+
+ ret = clk_prepare_enable(scp->clk);
+ if (ret) {
+ dev_err(dev, "failed to enable clocks\n");
+ goto free_rproc;
+ }
+
+ ret = scp_ipi_init(scp);
+ clk_disable_unprepare(scp->clk);
+ if (ret) {
+ dev_err(dev, "Failed to init ipi\n");
+ goto free_rproc;
+ }
+
+ /* register SCP initialization IPI */
+ ret = scp_ipi_register(pdev,
+ SCP_IPI_INIT,
+ scp_init_ipi_handler,
+ scp);
+ if (ret) {
+ dev_err(dev, "Failed to register IPI_SCP_INIT\n");
+ goto free_rproc;
+ }
+
+ mutex_init(&scp->lock);
+
+ init_waitqueue_head(&scp->run.wq);
+ init_waitqueue_head(&scp->ack_wq);
+
+ ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0), NULL,
+ scp_irq_handler, IRQF_ONESHOT,
+ pdev->name, scp);
+
+ if (ret) {
+ dev_err(dev, "failed to request irq\n");
+ goto destroy_mutex;
+ }
+
+ ret = rproc_add(rproc);
+ if (ret)
+ goto destroy_mutex;
+
+ return ret;
+
+destroy_mutex:
+ mutex_destroy(&scp->lock);
+free_rproc:
+ rproc_free(rproc);
+
+ return ret;
+}
+
+static int scp_remove(struct platform_device *pdev)
+{
+ struct mtk_scp *scp = platform_get_drvdata(pdev);
+
+ rproc_del(scp->rproc);
+ rproc_free(scp->rproc);
+
+ return 0;
+}
+
+static const struct of_device_id mtk_scp_of_match[] = {
+ { .compatible = "mediatek,mt8183-scp"},
+ {},
+};
+MODULE_DEVICE_TABLE(of, mtk_scp_of_match);
+
+static struct platform_driver mtk_scp_driver = {
+ .probe = scp_probe,
+ .remove = scp_remove,
+ .driver = {
+ .name = "mtk-scp",
+ .of_match_table = of_match_ptr(mtk_scp_of_match),
+ },
+};
+
+module_platform_driver(mtk_scp_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MediaTek SCP control driver");
diff --git a/drivers/remoteproc/mtk_scp_ipi.c b/drivers/remoteproc/mtk_scp_ipi.c
new file mode 100644
index 000000000000..f5d271c0f623
--- /dev/null
+++ b/drivers/remoteproc/mtk_scp_ipi.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2018 MediaTek Inc.
+
+#include <asm/barrier.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_data/mtk_scp.h>
+#include <linux/platform_device.h>
+
+#include "mtk_common.h"
+
+int scp_ipi_register(struct platform_device *pdev,
+ enum scp_ipi_id id,
+ scp_ipi_handler_t handler,
+ void *priv)
+{
+ struct mtk_scp *scp = platform_get_drvdata(pdev);
+ struct scp_ipi_desc *ipi_desc;
+
+ if (!scp) {
+ dev_err(&pdev->dev, "scp device is not ready\n");
+ return -EPROBE_DEFER;
+ }
+
+ if (WARN_ON(id < 0) || WARN_ON(id >= SCP_IPI_MAX) ||
+ WARN_ON(handler == NULL))
+ return -EINVAL;
+
+ ipi_desc = scp->ipi_desc;
+ ipi_desc[id].handler = handler;
+ ipi_desc[id].priv = priv;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(scp_ipi_register);
+
+void scp_ipi_unregister(struct platform_device *pdev, enum scp_ipi_id id)
+{
+ struct mtk_scp *scp = platform_get_drvdata(pdev);
+ struct scp_ipi_desc *ipi_desc;
+
+ if (!scp)
+ return;
+
+ if (WARN_ON(id < 0) || WARN_ON(id >= SCP_IPI_MAX))
+ return;
+
+ ipi_desc = scp->ipi_desc;
+ ipi_desc[id].handler = NULL;
+ ipi_desc[id].priv = NULL;
+}
+EXPORT_SYMBOL_GPL(scp_ipi_unregister);
+
+/*
+ * Copy src to dst, where dst is in SCP SRAM region.
+ * 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 *dst, const void *src, unsigned int len)
+{
+ void *ptr;
+ u32 val;
+ unsigned int i = 0;
+
+ if (!IS_ALIGNED((unsigned long)dst, 4)) {
+ ptr = (void *)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);
+ }
+
+ while (i + 4 <= len) {
+ val = *((u32 *)(src + i));
+ writel_relaxed(val, dst + i);
+ i += 4;
+ }
+ if (i < len) {
+ val = readl_relaxed(dst + i);
+ memcpy(&val, src + i, len - i);
+ writel_relaxed(val, dst + i);
+ }
+}
+EXPORT_SYMBOL_GPL(scp_memcpy_aligned);
+
+int scp_ipi_send(struct platform_device *pdev,
+ enum scp_ipi_id id,
+ void *buf,
+ unsigned int len,
+ unsigned int wait)
+{
+ struct mtk_scp *scp = platform_get_drvdata(pdev);
+ struct share_obj *send_obj = scp->send_buf;
+ unsigned long timeout;
+ int ret;
+
+ if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) ||
+ WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf))
+ return -EINVAL;
+
+ mutex_lock(&scp->lock);
+
+ ret = clk_prepare_enable(scp->clk);
+ if (ret) {
+ dev_err(scp->dev, "failed to enable clock\n");
+ return ret;
+ }
+
+ /* Wait until SCP receives the last command */
+ timeout = jiffies + msecs_to_jiffies(2000);
+ do {
+ if (time_after(jiffies, timeout)) {
+ dev_err(scp->dev, "%s: IPI timeout!\n", __func__);
+ ret = -EIO;
+ mutex_unlock(&scp->lock);
+ goto clock_disable;
+ }
+ } while (readl(scp->reg_base + MT8183_HOST_TO_SCP));
+
+ scp_memcpy_aligned(send_obj->share_buf, buf, len);
+
+ send_obj->len = len;
+ send_obj->id = id;
+
+ scp->ipi_id_ack[id] = false;
+ /*
+ * Ensure that all writes to SRAM are committed before sending the
+ * interrupt to SCP.
+ */
+ mb();
+ /* send the command to SCP */
+ writel(MT8183_HOST_IPC_INT_BIT, scp->reg_base + MT8183_HOST_TO_SCP);
+
+ mutex_unlock(&scp->lock);
+
+ if (wait) {
+ /* wait for SCP's ACK */
+ timeout = msecs_to_jiffies(wait);
+ ret = wait_event_timeout(scp->ack_wq,
+ scp->ipi_id_ack[id],
+ timeout);
+ scp->ipi_id_ack[id] = false;
+ if (WARN(!ret,
+ "scp ipi %d ack time out !", id))
+ ret = -EIO;
+ else
+ ret = 0;
+ }
+
+clock_disable:
+ clk_disable_unprepare(scp->clk);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(scp_ipi_send);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MediaTek scp IPI interface");
diff --git a/include/linux/platform_data/mtk_scp.h b/include/linux/platform_data/mtk_scp.h
new file mode 100644
index 000000000000..dfda05051235
--- /dev/null
+++ b/include/linux/platform_data/mtk_scp.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018 MediaTek Inc.
+ */
+
+#ifndef _MTK_SCP_H
+#define _MTK_SCP_H
+
+#include <linux/platform_device.h>
+
+typedef void (*scp_ipi_handler_t) (void *data,
+ unsigned int len,
+ void *priv);
+
+/**
+ * enum ipi_id - the id of inter-processor interrupt
+ *
+ * @SCP_IPI_INIT: The interrupt from scp is to notfiy kernel
+ * SCP initialization completed.
+ * IPI_SCP_INIT is sent from SCP when firmware is
+ * loaded. AP doesn't need to send IPI_SCP_INIT
+ * command to SCP.
+ * For other IPI below, AP should send the request
+ * to SCP to trigger the interrupt.
+ * @SCP_IPI_MAX: The maximum IPI number
+ */
+
+enum scp_ipi_id {
+ SCP_IPI_INIT = 0,
+ SCP_IPI_VDEC_H264,
+ SCP_IPI_VDEC_VP8,
+ SCP_IPI_VDEC_VP9,
+ SCP_IPI_VENC_H264,
+ SCP_IPI_VENC_VP8,
+ SCP_IPI_MDP,
+ SCP_IPI_CROS_HOST_CMD,
+ SCP_IPI_MAX,
+};
+
+/**
+ * scp_ipi_register - register an ipi function
+ *
+ * @pdev: SCP platform device
+ * @id: IPI ID
+ * @handler: IPI handler
+ * @priv: private data for IPI handler
+ *
+ * Register an ipi function to receive ipi interrupt from SCP.
+ *
+ * Return: Return 0 if ipi registers successfully, otherwise it is failed.
+ */
+int scp_ipi_register(struct platform_device *pdev,
+ enum scp_ipi_id id,
+ scp_ipi_handler_t handler,
+ void *priv);
+
+/**
+ * scp_ipi_unregister - unregister an ipi function
+ *
+ * @pdev: SCP platform device
+ * @id: IPI ID
+ *
+ * Unregister an ipi function to receive ipi interrupt from SCP.
+ */
+void scp_ipi_unregister(struct platform_device *pdev, enum scp_ipi_id id);
+
+/**
+ * scp_ipi_send - send data from AP to scp.
+ *
+ * @pdev: SCP platform device
+ * @id: IPI ID
+ * @buf: the data buffer
+ * @len: the data buffer length
+ * @wait: 1: need ack
+ *
+ * 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: Return 0 if sending data successfully, otherwise it is failed.
+ **/
+int scp_ipi_send(struct platform_device *pdev,
+ enum scp_ipi_id id,
+ void *buf,
+ unsigned int len,
+ unsigned int wait);
+
+/**
+ * scp_get_pdev - get SCP's platform device
+ *
+ * @pdev: the platform device of the module requesting SCP platform
+ * device for using SCP API.
+ *
+ * Return: Return NULL if it is failed.
+ * otherwise it is SCP's platform device
+ **/
+struct platform_device *scp_get_pdev(struct platform_device *pdev);
+
+/**
+ * scp_get_vdec_hw_capa - get video decoder hardware capability
+ *
+ * @pdev: SCP platform device
+ *
+ * Return: video decoder hardware capability
+ **/
+unsigned int scp_get_vdec_hw_capa(struct platform_device *pdev);
+
+/**
+ * scp_get_venc_hw_capa - get video encoder hardware capability
+ *
+ * @pdev: SCP platform device
+ *
+ * Return: video encoder hardware capability
+ **/
+unsigned int scp_get_venc_hw_capa(struct platform_device *pdev);
+
+/**
+ * scp_mapping_dm_addr - Mapping SRAM/DRAM to kernel virtual address
+ *
+ * @pdev: SCP platform device
+ * @mem_addr: SCP views memory address
+ *
+ * Mapping the SCP's SRAM address /
+ * DMEM (Data Extended Memory) memory address /
+ * Working buffer memory address to
+ * kernel virtual address.
+ *
+ * Return: Return ERR_PTR(-EINVAL) if mapping failed,
+ * otherwise the mapped kernel virtual address
+ **/
+void *scp_mapping_dm_addr(struct platform_device *pdev,
+ u32 mem_addr);
+
+#endif /* _MTK_SCP_H */
--
2.21.0.392.gf8f6787159e-goog