remoteproc/mediatek: add SCP support for mt8183

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>
Link: https://lore.kernel.org/r/20191112110330.179649-3-pihsun@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/Kconfig

@@ -23,6 +23,15 @@ 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

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

drivers/remoteproc/mtk_common.h

@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019 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>
+#include <linux/remoteproc/mtk_scp.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_WDT_CFG			0x84
+#define MT8183_SCP_CLK_SW_SEL		0x4000
+#define MT8183_SCP_CLK_DIV_SEL		0x4024
+#define MT8183_SCP_SRAM_PDN		0x402C
+#define MT8183_SCP_L1_SRAM_PD		0x4080
+#define MT8183_SCP_TCM_TAIL_SRAM_PD	0x4094
+
+#define MT8183_SCP_CACHE_SEL(x)		(0x14000 + (x) * 0x3000)
+#define MT8183_SCP_CACHE_CON		MT8183_SCP_CACHE_SEL(0)
+#define MT8183_SCP_DCACHE_CON		MT8183_SCP_CACHE_SEL(1)
+#define MT8183_SCP_CACHESIZE_8KB	BIT(8)
+#define MT8183_SCP_CACHE_CON_WAYEN	BIT(10)
+
+#define SCP_FW_VER_LEN			32
+#define SCP_SHARE_BUFFER_SIZE		288
+
+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 {
+	/* For protecting handler. */
+	struct mutex lock;
+	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 mtk_share_obj __iomem *recv_buf;
+	struct mtk_share_obj __iomem *send_buf;
+	struct scp_run run;
+	/* To prevent multiple ipi_send run concurrently. */
+	struct mutex send_lock;
+	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 mtk_share_obj - SRAM buffer shared with AP and SCP
+ *
+ * @id:		IPI id
+ * @len:	share buffer length
+ * @share_buf:	share buffer data
+ */
+struct mtk_share_obj {
+	u32 id;
+	u32 len;
+	u8 share_buf[SCP_SHARE_BUFFER_SIZE];
+};
+
+void scp_memcpy_aligned(void __iomem *dst, const void *src, unsigned int len);
+void scp_ipi_lock(struct mtk_scp *scp, u32 id);
+void scp_ipi_unlock(struct mtk_scp *scp, u32 id);
+
+#endif