[RFC,0/5] Add support for mt8183 SCP.

[RFC,0/5] Add support for mt8183 SCP.

[Pi-Hsun Shih]

Add support for controlling and communicating with mt8183's system
control processor (SCP), using the remoteproc & rpmsg framework.
And also add a cros_ec driver for CrOS EC host command over rpmsg.

The overall structure of the series is:
* remoteproc/mtk_scp.c: Control the start / stop of SCP (Patch 2).
* remoteproc/mtk_scp_ipi.c: Communicates to SCP using inter-processor
  interrupt (IPI) and shared memory (Patch 2, 3).
* rpmsg/mtk_rpmsg.c: Wrapper to wrap the IPI communication into a rpmsg
  device. Supports name service for SCP firmware to
  announce channels (Patch 4).
* platform/chrome/cros_ec_rpmsg.c: Communicates with the SCP over the
  rpmsg framework (like what platform/chrome/cros_ec_{i2c,spi}.c does)
  (Patch 5).

Since I'm not familiar with the remoteproc / rpmsg framework, and there
are not much other custom rpmsg driver for reference, would like some
review / comments on the overall structure of the driver.


Erin Lo (2):
  dt-bindings: Add a binding for Mediatek SCP
  remoteproc/mediatek: add SCP support for mt8183

Pi-Hsun Shih (3):
  remoteproc: move IPI interface into separate file.
  rpmsg: add rpmsg support for mt8183 SCP.
  mfd: cros_ec: add EC host command support using rpmsg.

 .../bindings/remoteproc/mtk,scp.txt           |  10 +
 drivers/mfd/cros_ec_dev.c                     |  10 +
 drivers/platform/chrome/Kconfig               |   8 +
 drivers/platform/chrome/Makefile              |   1 +
 drivers/platform/chrome/cros_ec_rpmsg.c       | 164 +++++++
 drivers/remoteproc/Kconfig                    |   9 +
 drivers/remoteproc/Makefile                   |   1 +
 drivers/remoteproc/mtk_common.h               |  76 +++
 drivers/remoteproc/mtk_scp.c                  | 441 ++++++++++++++++++
 drivers/remoteproc/mtk_scp_ipi.c              | 109 +++++
 drivers/rpmsg/Kconfig                         |   5 +
 drivers/rpmsg/Makefile                        |   1 +
 drivers/rpmsg/mtk_rpmsg.c                     | 341 ++++++++++++++
 include/linux/mfd/cros_ec.h                   |   1 +
 include/linux/mfd/cros_ec_commands.h          |   2 +
 include/linux/platform_data/mtk_scp.h         | 143 ++++++
 include/linux/rpmsg/mtk_rpmsg.h               |  34 ++
 17 files changed, 1356 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
 create mode 100644 drivers/platform/chrome/cros_ec_rpmsg.c
 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 drivers/rpmsg/mtk_rpmsg.c
 create mode 100644 include/linux/platform_data/mtk_scp.h
 create mode 100644 include/linux/rpmsg/mtk_rpmsg.h

-- 
2.20.1.415.g653613c723-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[RFC,1/5] dt-bindings: Add a binding for Mediatek SCP

[Pi-Hsun Shih]

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

Add a DT binding documentation of SCP for the
MT8183 SoC from Mediatek.

Signed-off-by: Erin Lo <erin.lo@mediatek.com>
---
 .../devicetree/bindings/remoteproc/mtk,scp.txt         | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/mtk,scp.txt

diff --git a/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt b/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
new file mode 100644
index 0000000000000..b07e5c4ca9af1
--- /dev/null
+++ b/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
@@ -0,0 +1,9 @@
+Mediatek SCP Bindings
+----------------------------------------
+
+This binding provides support for ARM Cortex M4 Co-processor found on some
+Mediatek SoCs.
+
+Required properties:
+- compatible		Should be "mediatek,mt8183-scp"
+- clocks		Clock for co-processor (See: ../clock/clock-bindings.txt)
-- 
2.20.1.415.g653613c723-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[RFC,2/5] remoteproc/mediatek: add SCP support for mt8183

[Pi-Hsun Shih]

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>
---
 drivers/remoteproc/Kconfig            |   9 +
 drivers/remoteproc/Makefile           |   1 +
 drivers/remoteproc/mtk_scp.c          | 568 ++++++++++++++++++++++++++
 include/linux/platform_data/mtk_scp.h | 136 ++++++
 4 files changed, 714 insertions(+)
 create mode 100644 drivers/remoteproc/mtk_scp.c
 create mode 100644 include/linux/platform_data/mtk_scp.h

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index f0abd26080447..ee0bda2376893 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 SCP (Cortex M4
+          on MT8183) 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 ce5d061e92be5..98e3498dbbe0e 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
 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_scp.c b/drivers/remoteproc/mtk_scp.c
new file mode 100644
index 0000000000000..7a1a8fe53b54a
--- /dev/null
+++ b/drivers/remoteproc/mtk_scp.c
@@ -0,0 +1,568 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2018 MediaTek Inc.
+
+#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 "remoteproc_internal.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 INIT_TIMEOUT_MS		2000
+#define IPI_TIMEOUT_MS		2000
+#define SCP_FW_VER_LEN		32
+
+#define MAX_CODE_SIZE 0x500000
+
+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 {
+	ipi_handler_t handler;
+	const char *name;
+	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 scp_mutex; /* for protecting mtk_scp data structure */
+	struct scp_ipi_desc ipi_desc[IPI_MAX];
+	bool ipi_id_ack[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];
+};
+
+int scp_ipi_register(struct platform_device *pdev,
+		     enum ipi_id id,
+		     ipi_handler_t handler,
+		     const char *name,
+		     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(id < 0 ||  id >= IPI_MAX || handler == NULL,
+	    "register scp ipi id %d with invalid arguments\n", id))
+		return -EINVAL;
+
+	ipi_desc = scp->ipi_desc;
+	ipi_desc[id].name = name;
+	ipi_desc[id].handler = handler;
+	ipi_desc[id].priv = priv;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(scp_ipi_register);
+
+int scp_ipi_send(struct platform_device *pdev,
+		 enum 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(id <= IPI_SCP_INIT || id >= IPI_MAX ||
+	    len > sizeof(send_obj->share_buf) || !buf,
+	    "failed to send ipi message\n"))
+		return -EINVAL;
+
+	ret = clk_prepare_enable(scp->clk);
+	if (ret) {
+		dev_err(scp->dev, "failed to enable clock\n");
+		return ret;
+	}
+
+	mutex_lock(&scp->scp_mutex);
+
+	 /* Wait until SCP receives the last command */
+	timeout = jiffies + msecs_to_jiffies(IPI_TIMEOUT_MS);
+	do {
+		if (time_after(jiffies, timeout)) {
+			dev_err(scp->dev, "scp_ipi_send: IPI timeout!\n");
+			ret = -EIO;
+			mutex_unlock(&scp->scp_mutex);
+			goto clock_disable;
+		}
+	} while (readl(scp->reg_base + MT8183_HOST_TO_SCP));
+
+	memcpy(send_obj->share_buf, buf, len);
+	send_obj->len = len;
+	send_obj->id = id;
+
+	scp->ipi_id_ack[id] = false;
+	/* send the command to SCP */
+	writel(MT8183_HOST_IPC_INT_BIT, scp->reg_base + MT8183_HOST_TO_SCP);
+
+	mutex_unlock(&scp->scp_mutex);
+
+	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);
+
+struct platform_device *scp_get_plat_device(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_plat_device);
+
+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 < IPI_MAX && ipi_desc[rcv_obj->id].handler) {
+		memcpy_fromio(tmp_data, &rcv_obj->share_buf, rcv_obj->len);
+		ipi_desc[rcv_obj->id].handler(&tmp_data[0],
+					      rcv_obj->len,
+					      ipi_desc[rcv_obj->id].priv);
+		scp->ipi_id_ack[rcv_obj->id] = true;
+		wake_up(&scp->ack_wq);
+	} else {
+		dev_err(scp->dev, "No such ipi id = %d\n", rcv_obj->id);
+	}
+}
+
+static int scp_ipi_init(struct mtk_scp *scp)
+{
+	size_t send_offset = 0x800 - 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 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);
+	}
+
+	/* 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;
+}
+
+static int mtk_scp_load(struct rproc *rproc, const struct firmware *fw)
+{
+	const struct mtk_scp *scp = rproc->priv;
+	struct device *dev = scp->dev;
+	int ret;
+
+	ret = clk_prepare_enable(scp->clk);
+	if (ret) {
+		dev_err(dev, "failed to enable clocks\n");
+		return ret;
+	}
+
+	writel(0x0, scp->reg_base + MT8183_SCP_SRAM_PDN);
+
+	memcpy(scp->sram_base, fw->data, fw->size);
+	return ret;
+}
+
+static int mtk_scp_start(struct rproc *rproc)
+{
+	struct mtk_scp *scp = (struct mtk_scp *)rproc->priv;
+	struct device *dev = scp->dev;
+	struct scp_run *run;
+	u32 val;
+	int ret;
+
+	ret = clk_prepare_enable(scp->clk);
+	if (ret) {
+		dev_err(dev, "failed to enable clocks\n");
+		return ret;
+	}
+
+	val = readl(scp->reg_base + MT8183_SW_RSTN);
+	val |= MT8183_SW_RSTN_BIT;
+	writel(val, scp->reg_base + MT8183_SW_RSTN);
+
+	run = &scp->run;
+
+	ret = wait_event_interruptible_timeout(
+					run->wq,
+					run->signaled,
+					msecs_to_jiffies(INIT_TIMEOUT_MS));
+
+	if (ret == 0) {
+		dev_err(dev, "wait scp initialization timeout!\n");
+		return -ETIME;
+	}
+	if (ret == -ERESTARTSYS) {
+		dev_err(dev, "wait scp interrupted by a signal!\n");
+		return -ERESTARTSYS;
+	}
+	dev_info(dev, "scp is ready. Fw version %s\n", run->fw_ver);
+
+	return 0;
+}
+
+static void *mtk_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 mtk_scp_stop(struct rproc *rproc)
+{
+	struct mtk_scp *scp = (struct mtk_scp *)rproc->priv;
+	u32 val;
+
+	val = readl(scp->reg_base + MT8183_SW_RSTN);
+	val &= ~MT8183_SW_RSTN_BIT;
+	writel(val, scp->reg_base + MT8183_SW_RSTN);
+
+	clk_disable_unprepare(scp->clk);
+
+	return 0;
+}
+
+static const struct rproc_ops mtk_scp_ops = {
+	.start		= mtk_scp_start,
+	.stop		= mtk_scp_stop,
+	.load		= mtk_scp_load,
+	.da_to_va	= mtk_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 = NULL;
+
+	ptr = mtk_scp_da_to_va(scp->rproc, mem_addr, 0);
+
+	if (ptr)
+		return ptr;
+	else
+		return ERR_PTR(-EINVAL);
+}
+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 mtk_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,
+			    &mtk_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);
+	scp->sram_size = resource_size(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;
+	}
+
+	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,
+			       IPI_SCP_INIT,
+			       scp_init_ipi_handler,
+			       "scp_init",
+			       scp);
+	if (ret) {
+		dev_err(dev, "Failed to register IPI_SCP_INIT\n");
+		goto free_rproc;
+	}
+
+	ret = devm_request_irq(dev,
+			       platform_get_irq(pdev, 0),
+			       scp_irq_handler,
+			       0,
+			       pdev->name,
+			       scp);
+
+	if (ret) {
+		dev_err(dev, "failed to request irq\n");
+		goto free_rproc;
+	}
+
+	mutex_init(&scp->scp_mutex);
+
+	init_waitqueue_head(&scp->run.wq);
+	init_waitqueue_head(&scp->ack_wq);
+
+	ret = rproc_add(rproc);
+	if (ret)
+		goto destroy_mutex;
+
+	return ret;
+
+destroy_mutex:
+	mutex_destroy(&scp->scp_mutex);
+free_rproc:
+	rproc_free(rproc);
+
+	return ret;
+}
+
+static int mtk_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 = mtk_scp_probe,
+	.remove = mtk_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/include/linux/platform_data/mtk_scp.h b/include/linux/platform_data/mtk_scp.h
new file mode 100644
index 0000000000000..118838c91564f
--- /dev/null
+++ b/include/linux/platform_data/mtk_scp.h
@@ -0,0 +1,136 @@
+/* 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 (*ipi_handler_t) (void *data,
+			       unsigned int len,
+			       void *priv);
+
+/**
+ * enum ipi_id - the id of inter-processor interrupt
+ *
+ * @IPI_SCP_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.
+ * @IPI_MAX:		 The maximum IPI number
+ */
+
+enum ipi_id {
+	IPI_SCP_INIT = 0,
+	IPI_MDP,
+	IPI_MAX,
+};
+
+/**
+ * enum rst_id - reset id to register reset function for SCP watchdog timeout
+ *
+ * @SCP_RST_ENC: encoder reset id
+ * @SCP_RST_DEC: decoder reset id
+ * @SCP_RST_MDP: MDP (Media Data Path) reset id
+ * @SCP_RST_MAX: maximum reset id
+ */
+enum rst_id {
+	SCP_RST_ENC,
+	SCP_RST_DEC,
+	SCP_RST_MDP,
+	SCP_RST_MAX,
+};
+
+/**
+ * scp_ipi_register - register an ipi function
+ *
+ * @pdev:	SCP platform device
+ * @id:		IPI ID
+ * @handler:	IPI handler
+ * @name:	IPI name
+ * @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 ipi_id id,
+		     ipi_handler_t handler,
+		     const char *name,
+		     void *priv);
+
+/**
+ * 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 ipi_id id,
+		 void *buf,
+		 unsigned int len,
+		 unsigned int wait);
+
+/**
+ * scp_get_plat_device - 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_plat_device(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 */
-- 
2.20.1.415.g653613c723-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[RFC,3/5] remoteproc: move IPI interface into separate file.

[Pi-Hsun Shih]

Move the IPI interface into a separate file mtk_scp_ipi.c, so the things
that use the interface only can depend on the module only.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
 drivers/remoteproc/Makefile      |   2 +-
 drivers/remoteproc/mtk_common.h  |  73 +++++++++++++++
 drivers/remoteproc/mtk_scp.c     | 153 +------------------------------
 drivers/remoteproc/mtk_scp_ipi.c | 109 ++++++++++++++++++++++
 4 files changed, 184 insertions(+), 153 deletions(-)
 create mode 100644 drivers/remoteproc/mtk_common.h
 create mode 100644 drivers/remoteproc/mtk_scp_ipi.c

diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index 98e3498dbbe0e..16b3e5e7a81c8 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -10,7 +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
+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 0000000000000..ae55fca2ce2d7
--- /dev/null
+++ b/drivers/remoteproc/mtk_common.h
@@ -0,0 +1,73 @@
+// 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 {
+	ipi_handler_t handler;
+	const char *name;
+	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 scp_mutex; /* for protecting mtk_scp data structure */
+	struct scp_ipi_desc ipi_desc[IPI_MAX];
+	bool ipi_id_ack[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];
+};
+
+#endif
diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index 7a1a8fe53b54a..aaebe96bcfd66 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -14,163 +14,12 @@
 #include <linux/remoteproc.h>
 
 #include "remoteproc_internal.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
+#include "mtk_common.h"
 
 #define INIT_TIMEOUT_MS		2000
-#define IPI_TIMEOUT_MS		2000
-#define SCP_FW_VER_LEN		32
 
 #define MAX_CODE_SIZE 0x500000
 
-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 {
-	ipi_handler_t handler;
-	const char *name;
-	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 scp_mutex; /* for protecting mtk_scp data structure */
-	struct scp_ipi_desc ipi_desc[IPI_MAX];
-	bool ipi_id_ack[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];
-};
-
-int scp_ipi_register(struct platform_device *pdev,
-		     enum ipi_id id,
-		     ipi_handler_t handler,
-		     const char *name,
-		     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(id < 0 ||  id >= IPI_MAX || handler == NULL,
-	    "register scp ipi id %d with invalid arguments\n", id))
-		return -EINVAL;
-
-	ipi_desc = scp->ipi_desc;
-	ipi_desc[id].name = name;
-	ipi_desc[id].handler = handler;
-	ipi_desc[id].priv = priv;
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(scp_ipi_register);
-
-int scp_ipi_send(struct platform_device *pdev,
-		 enum 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(id <= IPI_SCP_INIT || id >= IPI_MAX ||
-	    len > sizeof(send_obj->share_buf) || !buf,
-	    "failed to send ipi message\n"))
-		return -EINVAL;
-
-	ret = clk_prepare_enable(scp->clk);
-	if (ret) {
-		dev_err(scp->dev, "failed to enable clock\n");
-		return ret;
-	}
-
-	mutex_lock(&scp->scp_mutex);
-
-	 /* Wait until SCP receives the last command */
-	timeout = jiffies + msecs_to_jiffies(IPI_TIMEOUT_MS);
-	do {
-		if (time_after(jiffies, timeout)) {
-			dev_err(scp->dev, "scp_ipi_send: IPI timeout!\n");
-			ret = -EIO;
-			mutex_unlock(&scp->scp_mutex);
-			goto clock_disable;
-		}
-	} while (readl(scp->reg_base + MT8183_HOST_TO_SCP));
-
-	memcpy(send_obj->share_buf, buf, len);
-	send_obj->len = len;
-	send_obj->id = id;
-
-	scp->ipi_id_ack[id] = false;
-	/* send the command to SCP */
-	writel(MT8183_HOST_IPC_INT_BIT, scp->reg_base + MT8183_HOST_TO_SCP);
-
-	mutex_unlock(&scp->scp_mutex);
-
-	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);
-
 struct platform_device *scp_get_plat_device(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
diff --git a/drivers/remoteproc/mtk_scp_ipi.c b/drivers/remoteproc/mtk_scp_ipi.c
new file mode 100644
index 0000000000000..6923066869874
--- /dev/null
+++ b/drivers/remoteproc/mtk_scp_ipi.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2018 MediaTek Inc.
+
+#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"
+
+#define IPI_TIMEOUT_MS		2000
+
+int scp_ipi_register(struct platform_device *pdev,
+		     enum ipi_id id,
+		     ipi_handler_t handler,
+		     const char *name,
+		     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(id < 0 || id >= IPI_MAX || handler == NULL,
+	    "register scp ipi id %d with invalid arguments\n", id))
+		return -EINVAL;
+
+	ipi_desc = scp->ipi_desc;
+	ipi_desc[id].name = name;
+	ipi_desc[id].handler = handler;
+	ipi_desc[id].priv = priv;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(scp_ipi_register);
+
+int scp_ipi_send(struct platform_device *pdev,
+		 enum 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(id <= IPI_SCP_INIT || id >= IPI_MAX ||
+	    len > sizeof(send_obj->share_buf) || !buf,
+	    "failed to send ipi message\n"))
+		return -EINVAL;
+
+	ret = clk_prepare_enable(scp->clk);
+	if (ret) {
+		dev_err(scp->dev, "failed to enable clock\n");
+		return ret;
+	}
+
+	mutex_lock(&scp->scp_mutex);
+
+	 /* Wait until SCP receives the last command */
+	timeout = jiffies + msecs_to_jiffies(IPI_TIMEOUT_MS);
+	do {
+		if (time_after(jiffies, timeout)) {
+			dev_err(scp->dev, "scp_ipi_send: IPI timeout!\n");
+			ret = -EIO;
+			mutex_unlock(&scp->scp_mutex);
+			goto clock_disable;
+		}
+	} while (readl(scp->reg_base + MT8183_HOST_TO_SCP));
+
+	memcpy(send_obj->share_buf, buf, len);
+	send_obj->len = len;
+	send_obj->id = id;
+
+	scp->ipi_id_ack[id] = false;
+	/* send the command to SCP */
+	writel(MT8183_HOST_IPC_INT_BIT, scp->reg_base + MT8183_HOST_TO_SCP);
+
+	mutex_unlock(&scp->scp_mutex);
+
+	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");
-- 
2.20.1.415.g653613c723-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[RFC,4/5] rpmsg: add rpmsg support for mt8183 SCP.

[Pi-Hsun Shih]

Add a simple rpmsg support for mt8183 SCP, that use IPI / IPC directly.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
---
There are lots of TODO comments on things that are not done yet / I have
doubt on whether it's the best way to do it.

 drivers/remoteproc/mtk_common.h       |   3 +
 drivers/remoteproc/mtk_scp.c          |  30 ++-
 drivers/remoteproc/mtk_scp_ipi.c      |   2 +-
 drivers/rpmsg/Kconfig                 |   5 +
 drivers/rpmsg/Makefile                |   1 +
 drivers/rpmsg/mtk_rpmsg.c             | 341 ++++++++++++++++++++++++++
 include/linux/platform_data/mtk_scp.h |   7 +
 include/linux/rpmsg/mtk_rpmsg.h       |  34 +++
 8 files changed, 419 insertions(+), 4 deletions(-)
 create mode 100644 drivers/rpmsg/mtk_rpmsg.c
 create mode 100644 include/linux/rpmsg/mtk_rpmsg.h

diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
index ae55fca2ce2d7..cdd4919a402a8 100644
--- a/drivers/remoteproc/mtk_common.h
+++ b/drivers/remoteproc/mtk_common.h
@@ -54,6 +54,9 @@ struct mtk_scp {
 	void __iomem *cpu_addr;
 	phys_addr_t phys_addr;
 	size_t dram_size;
+
+	struct platform_device *pdev;
+	struct rproc_subdev *rpmsg_subdev;
 };
 
 /**
diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index aaebe96bcfd66..0ed7904809dce 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -12,6 +12,7 @@
 #include <linux/platform_data/mtk_scp.h>
 #include <linux/platform_device.h>
 #include <linux/remoteproc.h>
+#include <linux/rpmsg/mtk_rpmsg.h>
 
 #include "remoteproc_internal.h"
 #include "mtk_common.h"
@@ -278,6 +279,24 @@ static int scp_map_memory_region(struct mtk_scp *scp)
 	return 0;
 }
 
+static void scp_add_rpmsg_subdev(struct mtk_scp *scp)
+{
+	scp->rpmsg_subdev =
+		mtk_rpmsg_create_rproc_subdev(scp->pdev, scp->rproc);
+	if (scp->rpmsg_subdev) {
+		rproc_add_subdev(scp->rproc, scp->rpmsg_subdev);
+	}
+}
+
+static void scp_remove_rpmsg_subdev(struct mtk_scp *scp)
+{
+	if (scp->rpmsg_subdev) {
+		rproc_remove_subdev(scp->rproc, scp->rpmsg_subdev);
+		mtk_rpmsg_destroy_rproc_subdev(scp->rpmsg_subdev);
+		scp->rpmsg_subdev = NULL;
+	}
+}
+
 static int mtk_scp_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -301,6 +320,7 @@ static int mtk_scp_probe(struct platform_device *pdev)
 	scp = (struct mtk_scp *)rproc->priv;
 	scp->rproc = rproc;
 	scp->dev = dev;
+	scp->pdev = pdev;
 	platform_set_drvdata(pdev, scp);
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sram");
@@ -372,13 +392,16 @@ static int mtk_scp_probe(struct platform_device *pdev)
 	init_waitqueue_head(&scp->run.wq);
 	init_waitqueue_head(&scp->ack_wq);
 
+	scp_add_rpmsg_subdev(scp);
+
 	ret = rproc_add(rproc);
 	if (ret)
-		goto destroy_mutex;
+		goto remove_subdev;
 
-	return ret;
+	return 0;
 
-destroy_mutex:
+remove_subdev:
+	scp_remove_rpmsg_subdev(scp);
 	mutex_destroy(&scp->scp_mutex);
 free_rproc:
 	rproc_free(rproc);
@@ -390,6 +413,7 @@ static int mtk_scp_remove(struct platform_device *pdev)
 {
 	struct mtk_scp *scp = platform_get_drvdata(pdev);
 
+	scp_remove_rpmsg_subdev(scp);
 	rproc_del(scp->rproc);
 	rproc_free(scp->rproc);
 
diff --git a/drivers/remoteproc/mtk_scp_ipi.c b/drivers/remoteproc/mtk_scp_ipi.c
index 6923066869874..1b72c5cc72d36 100644
--- a/drivers/remoteproc/mtk_scp_ipi.c
+++ b/drivers/remoteproc/mtk_scp_ipi.c
@@ -50,7 +50,7 @@ int scp_ipi_send(struct platform_device *pdev,
 	unsigned long timeout;
 	int ret;
 
-	if (WARN(id <= IPI_SCP_INIT || id >= IPI_MAX ||
+	if (WARN(id <= IPI_NS_SERVICE || id >= IPI_MAX ||
 	    len > sizeof(send_obj->share_buf) || !buf,
 	    "failed to send ipi message\n"))
 		return -EINVAL;
diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
index d0322b41eca54..b8364a397bb60 100644
--- a/drivers/rpmsg/Kconfig
+++ b/drivers/rpmsg/Kconfig
@@ -55,4 +55,9 @@ config RPMSG_VIRTIO
 	select RPMSG
 	select VIRTIO
 
+config RPMSG_MTK_SCP
+	tristate "MediaTek SCP"
+	depends on MTK_SCP
+	select RPMSG
+
 endmenu
diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile
index 9aa859502d275..a0c1dcefa36ee 100644
--- a/drivers/rpmsg/Makefile
+++ b/drivers/rpmsg/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_RPMSG_QCOM_GLINK_NATIVE) += qcom_glink_native.o
 obj-$(CONFIG_RPMSG_QCOM_GLINK_SMEM) += qcom_glink_smem.o
 obj-$(CONFIG_RPMSG_QCOM_SMD)	+= qcom_smd.o
 obj-$(CONFIG_RPMSG_VIRTIO)	+= virtio_rpmsg_bus.o
+obj-$(CONFIG_RPMSG_MTK_SCP)	+= mtk_rpmsg.o
diff --git a/drivers/rpmsg/mtk_rpmsg.c b/drivers/rpmsg/mtk_rpmsg.c
new file mode 100644
index 0000000000000..66b39eaae51f2
--- /dev/null
+++ b/drivers/rpmsg/mtk_rpmsg.c
@@ -0,0 +1,341 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright 2018 Google LLC.
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_data/mtk_scp.h>
+#include <linux/platform_device.h>
+#include <linux/remoteproc.h>
+#include <linux/rpmsg/mtk_rpmsg.h>
+#include <linux/workqueue.h>
+
+#include "rpmsg_internal.h"
+
+// TODO: This is built on top of scp_ipi_register / scp_ipi_send in mtk_scp.h.
+// It's probably better to move the implementation of register / send to here
+// instead of in remoteproc/mtk_scp_ipi.c
+// TODO: Do we need some sort of vring for performance? We may be able to get
+// rid of this file if so, but that would require SCP firmware support too.
+
+struct mtk_rpmsg_device {
+	struct rpmsg_device rpdev;
+
+	struct platform_device *scp_pdev;
+};
+
+struct mtk_rpmsg_endpoint {
+	struct rpmsg_endpoint ept;
+	u32 ipi_id;
+	struct platform_device *scp_pdev;
+};
+
+// TODO: Naming is hard...
+struct mtk_rpmsg_rproc_subdev {
+	struct rproc *scp_rproc;
+	struct platform_device *scp_pdev;
+	struct rpmsg_endpoint *ns_ept;
+	struct rproc_subdev subdev;
+};
+
+#define to_mtk_subdev(d) container_of(d, struct mtk_rpmsg_rproc_subdev, subdev);
+
+struct mtk_register_device_work {
+	struct work_struct register_work;
+	struct platform_device *scp_pdev;
+	char name[RPMSG_NAME_SIZE];
+	u32 addr;
+};
+
+/**
+ * TODO: This is copied from virtio_rpmsg_bus.
+ * struct rpmsg_ns_msg - dynamic name service announcement message
+ * @name: name of remote service that is published
+ * @addr: address of remote service that is published
+ *
+ * This message is sent across to publish a new service, or announce
+ * about its removal. When we receive these messages, an appropriate
+ * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
+ * or ->remove() handler of the appropriate rpmsg driver will be invoked
+ * (if/as-soon-as one is registered).
+ */
+struct rpmsg_ns_msg {
+	char name[RPMSG_NAME_SIZE];
+	u32 addr;
+} __packed;
+
+#define to_scp_device(r)	container_of(r, struct mtk_rpmsg_device, rpdev)
+#define to_scp_endpoint(r)	container_of(r, struct mtk_rpmsg_endpoint, ept)
+
+static const struct rpmsg_endpoint_ops mtk_rpmsg_endpoint_ops;
+
+static void __ept_release(struct kref *kref)
+{
+	struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
+						  refcount);
+	kfree(to_scp_endpoint(ept));
+}
+
+static void mtk_rpmsg_ipi_handler(void *data, unsigned int len, void *priv)
+{
+	struct mtk_rpmsg_endpoint *mept = priv;
+	struct rpmsg_endpoint *ept = &mept->ept;
+
+	// TODO: What if the cb() returns error?
+	(*ept->cb)(ept->rpdev, data, len, ept->priv, mept->ipi_id);
+}
+
+static struct rpmsg_endpoint *
+__rpmsg_create_ept(struct platform_device *scp_pdev, struct rpmsg_device *rpdev,
+		   rpmsg_rx_cb_t cb, void *priv,
+		   u32 id, const char *name)
+{
+	struct mtk_rpmsg_endpoint *mept;
+	struct rpmsg_endpoint *ept;
+
+	int ret;
+
+	mept = kzalloc(sizeof(*mept), GFP_KERNEL);
+	if (!mept)
+		return NULL;
+	mept->ipi_id = id;
+	mept->scp_pdev = scp_pdev;
+
+	ept = &mept->ept;
+	kref_init(&ept->refcount);
+
+	ept->rpdev = rpdev;
+	ept->cb = cb;
+	ept->priv = priv;
+	ept->ops = &mtk_rpmsg_endpoint_ops;
+
+	ret = scp_ipi_register(scp_pdev, id, mtk_rpmsg_ipi_handler, name, mept);
+	if (ret) {
+		dev_err(&scp_pdev->dev, "ipi register failed, id = %d", id);
+		kref_put(&ept->refcount, __ept_release);
+		return NULL;
+	}
+
+	return ept;
+}
+
+static struct rpmsg_endpoint *
+mtk_rpmsg_create_ept(struct rpmsg_device *rpdev, rpmsg_rx_cb_t cb, void *priv,
+		     struct rpmsg_channel_info chinfo)
+{
+	struct platform_device *scp_pdev = to_scp_device(rpdev)->scp_pdev;
+	// TODO: Is using src as IPI id "correct"?
+	return __rpmsg_create_ept(scp_pdev, rpdev, cb, priv, chinfo.src,
+				  chinfo.name);
+}
+
+static const struct rpmsg_device_ops mtk_rpmsg_device_ops = {
+	.create_ept = mtk_rpmsg_create_ept,
+};
+
+static void mtk_rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
+{
+	kref_put(&ept->refcount, __ept_release);
+}
+
+static int __mtk_rpmsg_send(struct mtk_rpmsg_endpoint *mept, void *data,
+			    int len, bool wait)
+{
+	// TODO: The "wait" is not same as what scp_ipi_send's "wait" means, so
+	// this is not correct.
+	// (first wait for there's space of tx buffer, second wait for the ack
+	// from scp.)
+	return scp_ipi_send(mept->scp_pdev, mept->ipi_id, data, len,
+			    wait ? 200 : 0);
+}
+
+static int mtk_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
+{
+	struct mtk_rpmsg_endpoint *mept = to_scp_endpoint(ept);
+
+	return __mtk_rpmsg_send(mept, data, len, true);
+}
+
+static int mtk_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
+{
+	struct mtk_rpmsg_endpoint *mept = to_scp_endpoint(ept);
+
+	return __mtk_rpmsg_send(mept, data, len, false);
+}
+
+static const struct rpmsg_endpoint_ops mtk_rpmsg_endpoint_ops = {
+	.destroy_ept = mtk_rpmsg_destroy_ept,
+	.send = mtk_rpmsg_send,
+	.trysend = mtk_rpmsg_trysend,
+};
+
+static void mtk_rpmsg_release_device(struct device *dev)
+{
+	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
+	struct mtk_rpmsg_device *mdev = to_scp_device(rpdev);
+
+	kfree(mdev);
+}
+
+static void mtk_register_device_work_function(struct work_struct *register_work)
+{
+	struct mtk_rpmsg_device *mdev;
+	struct rpmsg_device *rpdev;
+
+	struct mtk_register_device_work *work = container_of(
+		register_work, struct mtk_register_device_work, register_work);
+	struct platform_device *scp_pdev = work->scp_pdev;
+
+	int ret;
+
+	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	if (!mdev) {
+		goto free_work;
+	}
+
+	mdev->scp_pdev = scp_pdev;
+
+	rpdev = &mdev->rpdev;
+	rpdev->ops = &mtk_rpmsg_device_ops;
+	rpdev->src = work->addr;
+	rpdev->dst = RPMSG_ADDR_ANY;
+	strncpy(rpdev->id.name, work->name, RPMSG_NAME_SIZE);
+
+	rpdev->dev.parent = &scp_pdev->dev;
+	rpdev->dev.release = mtk_rpmsg_release_device;
+
+	ret = rpmsg_register_device(rpdev);
+
+	if (ret) {
+		dev_err(&scp_pdev->dev, "rpmsg register device failed\n");
+		goto free_work;
+	}
+	return;
+
+free_work:
+	// TODO: Is it reasonable to free the work itself in the handler?
+	kfree(register_work);
+}
+
+static int mtk_rpmsg_create_device(struct platform_device *scp_pdev,
+				    char *name, u32 addr)
+{
+	struct mtk_register_device_work *work;
+
+	// This is called in interrupt context from name service callback.
+	work = kzalloc(sizeof(*work), GFP_ATOMIC);
+	if (!work)
+		return -ENOMEM;
+
+	INIT_WORK(&work->register_work, mtk_register_device_work_function);
+	work->scp_pdev = scp_pdev;
+	strncpy(work->name, name, RPMSG_NAME_SIZE);
+	work->addr = addr;
+	// rpmsg_register_device can't be called in interrupt context, so need
+	// to schedule a work for it.
+	// TODO: Or should we change mtk_scp to call the callback in
+	// non-interrupt context?
+	schedule_work(&work->register_work);
+	return 0;
+}
+
+static int mtk_rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
+			   void *priv, u32 src)
+{
+	struct rpmsg_ns_msg *msg = data;
+	struct platform_device *scp_pdev = priv;
+	struct device *dev = &scp_pdev->dev;
+
+	int ret;
+
+	if (len != sizeof(*msg)) {
+		dev_err(dev, "malformed ns msg (%d)\n", len);
+		return -EINVAL;
+	}
+
+	/*
+	 * the name service ept does _not_ belong to a real rpmsg channel,
+	 * and is handled by the rpmsg bus itself.
+	 * for sanity reasons, make sure a valid rpdev has _not_ sneaked
+	 * in somehow.
+	 */
+	if (rpdev) {
+		dev_err(dev, "anomaly: ns ept has an rpdev handle\n");
+		return -EINVAL;
+	}
+
+	/* don't trust the remote processor for null terminating the name */
+	msg->name[RPMSG_NAME_SIZE - 1] = '\0';
+
+	dev_info(dev, "creating channel %s addr 0x%x\n", msg->name, msg->addr);
+
+	ret = mtk_rpmsg_create_device(scp_pdev, msg->name, msg->addr);
+	if (ret) {
+		dev_err(dev, "create rpmsg device failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+int mtk_rpmsg_prepare(struct rproc_subdev *subdev)
+{
+	struct mtk_rpmsg_rproc_subdev *mtk_subdev;
+	struct platform_device *scp_pdev;
+
+	mtk_subdev = to_mtk_subdev(subdev);
+	scp_pdev = mtk_subdev->scp_pdev;
+
+	/* a dedicated endpoint handles the name service msgs */
+	mtk_subdev->ns_ept =
+		__rpmsg_create_ept(scp_pdev, NULL, mtk_rpmsg_ns_cb, scp_pdev,
+				   IPI_NS_SERVICE, "name-service");
+	if (!mtk_subdev->ns_ept) {
+		dev_err(&scp_pdev->dev,
+			"failed to create name service endpoint\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void mtk_rpmsg_unprepare(struct rproc_subdev *subdev)
+{
+	struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev);
+
+	kref_put(&mtk_subdev->ns_ept->refcount, __ept_release);
+	// TODO: unregister all rpmsg devices created by name service here.
+}
+
+struct rproc_subdev *
+mtk_rpmsg_create_rproc_subdev(struct platform_device *scp_pdev,
+			      struct rproc *scp_rproc)
+{
+	struct mtk_rpmsg_rproc_subdev *mtk_subdev;
+	struct device *dev = &scp_pdev->dev;
+
+	mtk_subdev = kzalloc(sizeof(*mtk_subdev), GFP_KERNEL);
+	if (!mtk_subdev) {
+		dev_err(dev, "allocate rproc subdevice failed.\n");
+		return NULL;
+	}
+	mtk_subdev->scp_pdev = scp_pdev;
+	mtk_subdev->scp_rproc = scp_rproc;
+	mtk_subdev->subdev.prepare = mtk_rpmsg_prepare;
+	mtk_subdev->subdev.unprepare = mtk_rpmsg_unprepare;
+
+	return &mtk_subdev->subdev;
+}
+EXPORT_SYMBOL_GPL(mtk_rpmsg_create_rproc_subdev);
+
+void mtk_rpmsg_destroy_rproc_subdev(struct rproc_subdev *subdev)
+{
+	struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev);
+
+	kfree(mtk_subdev);
+}
+EXPORT_SYMBOL_GPL(mtk_rpmsg_destroy_rproc_subdev);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MediaTek scp rpmsg driver");
diff --git a/include/linux/platform_data/mtk_scp.h b/include/linux/platform_data/mtk_scp.h
index 118838c91564f..4b3cf4f63fbe9 100644
--- a/include/linux/platform_data/mtk_scp.h
+++ b/include/linux/platform_data/mtk_scp.h
@@ -27,7 +27,14 @@ typedef void (*ipi_handler_t) (void *data,
 
 enum ipi_id {
 	IPI_SCP_INIT = 0,
+	// TODO: Should this just be part of the response of IPI_SCP_INIT
+	// instead? e.g. the initial IPI_SCP_INIT from SCP sends a list of
+	// channels.
+	IPI_NS_SERVICE,
 	IPI_MDP,
+	// TODO: Since we'll not be having all IPI numbers here after the name
+	// service & rpmsg, this IPI_MAX need to be manually specified and sync
+	// with the firmware.
 	IPI_MAX,
 };
 
diff --git a/include/linux/rpmsg/mtk_rpmsg.h b/include/linux/rpmsg/mtk_rpmsg.h
new file mode 100644
index 0000000000000..c55dbd658dde1
--- /dev/null
+++ b/include/linux/rpmsg/mtk_rpmsg.h
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright 2018 Google LLC.
+
+#ifndef __LINUX_RPMSG_MTK_RPMSG_H
+#define __LINUX_RPMSG_MTK_RPMSG_H
+
+#include <linux/device.h>
+#include <linux/remoteproc.h>
+
+#if IS_ENABLED(CONFIG_RPMSG_MTK_SCP)
+
+struct rproc_subdev *
+mtk_rpmsg_create_rproc_subdev(struct platform_device *scp_pdev,
+			      struct rproc *scp_rproc);
+
+void mtk_rpmsg_destroy_rproc_subdev(struct rproc_subdev *subdev);
+
+#else
+
+static inline struct rproc_subdev *
+mtk_rpmsg_create_rproc_subdev(struct platform_device *scp_pdev,
+			      struct rproc *scp_rproc)
+{
+	return NULL;
+}
+
+static inline void mtk_rpmsg_destroy_rproc_subdev(struct rproc_subdev *subdev)
+{
+}
+
+#endif
+
+#endif
-- 
2.20.1.415.g653613c723-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [RFC,1/5] dt-bindings: Add a binding for Mediatek SCP

[Rob Herring]

On Wed, Dec 26, 2018 at 03:53:09PM +0800, Pi-Hsun Shih wrote:
> From: Erin Lo <erin.lo@mediatek.com>
> 
> Add a DT binding documentation of SCP for the
> MT8183 SoC from Mediatek.
> 
> Signed-off-by: Erin Lo <erin.lo@mediatek.com>
> ---
>  .../devicetree/bindings/remoteproc/mtk,scp.txt         | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
> 
> diff --git a/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt b/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
> new file mode 100644
> index 0000000000000..b07e5c4ca9af1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/remoteproc/mtk,scp.txt
> @@ -0,0 +1,9 @@
> +Mediatek SCP Bindings
> +----------------------------------------
> +
> +This binding provides support for ARM Cortex M4 Co-processor found on some
> +Mediatek SoCs.
> +
> +Required properties:
> +- compatible		Should be "mediatek,mt8183-scp"
> +- clocks		Clock for co-processor (See: ../clock/clock-bindings.txt)

Seems like this is going to be incomplete considering this used for the 
CrOS EC.

Rob

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel