[PATCH v2 7/9] remoteproc: mediatek: Add SCP core 1 as a rproc subdevice

[Tinghan Shen <tinghan.shen@mediatek.com>]

Because the clock and SRAM power is controlled by SCP core 0, SCP core 1
has to be boot after SCP core 0. We use the rproc subdev to achieve this
purpose.

The watchdog timeout handler of SCP core 1 is added as part of the rproc
subdevice. This allows SCP core 0 to handle watchdog timeout coming from
SCP core 1.

Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
---
 drivers/remoteproc/mtk_common.h |   9 +++
 drivers/remoteproc/mtk_scp.c    | 130 ++++++++++++++++++++++++++++++++
 2 files changed, 139 insertions(+)

diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
index 5582f4207fbf..67b41866a100 100644
--- a/drivers/remoteproc/mtk_common.h
+++ b/drivers/remoteproc/mtk_common.h
@@ -99,6 +99,14 @@ struct scp_ipi_desc {
 	void *priv;
 };
 
+struct scp_subdev_core {
+	struct rproc_subdev subdev;
+	struct mtk_scp *main_scp;
+	void (*scp_dual_wdt_timeout)(struct mtk_scp *scp, u32 scp_to_host);
+};
+
+#define to_subdev_core(d) container_of(d, struct scp_subdev_core, subdev)
+
 struct mtk_scp;
 
 struct mtk_scp_of_data {
@@ -144,6 +152,7 @@ struct mtk_scp {
 	size_t dram_size;
 
 	struct rproc_subdev *rpmsg_subdev;
+	struct rproc_subdev *dual_subdev;
 };
 
 /**
diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index b8a4db581179..d0e9e19e251f 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -244,6 +244,13 @@ static void mt8195_scp_irq_handler(struct mtk_scp *scp)
 	} else {
 		if (readl(scp->reg_base + MT8195_SYS_STATUS) & MT8195_CORE1_WDT) {
 			writel(1, scp->reg_base + MT8195_CORE1_WDT_IRQ);
+
+			if (scp->dual_subdev) {
+				struct scp_subdev_core *subdev_core;
+
+				subdev_core = to_subdev_core(scp->dual_subdev);
+				subdev_core->scp_dual_wdt_timeout(scp, scp_to_host);
+			}
 		} else {
 			writel(1, scp->reg_base + MT8192_CORE0_WDT_IRQ);
 			scp_wdt_handler(scp, scp_to_host);
@@ -925,6 +932,118 @@ static void scp_remove_rpmsg_subdev(struct mtk_scp *scp)
 	}
 }
 
+static struct mtk_scp *scp_dual_get(struct mtk_scp *scp)
+{
+	struct device *dev = scp->dev;
+	struct device_node *np;
+	struct platform_device *dual_pdev;
+
+	np = of_parse_phandle(dev->of_node, "mediatek,scp-core", 0);
+	dual_pdev = of_find_device_by_node(np);
+	of_node_put(np);
+
+	if (!dual_pdev) {
+		dev_err(dev, "No scp-dual pdev\n");
+		return NULL;
+	}
+
+	return platform_get_drvdata(dual_pdev);
+}
+
+static void scp_dual_put(struct mtk_scp *scp)
+{
+	put_device(scp->dev);
+}
+
+static int scp_dual_rproc_start(struct rproc_subdev *subdev)
+{
+	struct scp_subdev_core *subdev_core = to_subdev_core(subdev);
+	struct mtk_scp *scp_dual;
+
+	scp_dual = scp_dual_get(subdev_core->main_scp);
+	if (!scp_dual)
+		return -ENODEV;
+
+	rproc_boot(scp_dual->rproc);
+	scp_dual_put(scp_dual);
+
+	return 0;
+}
+
+static void scp_dual_rproc_stop(struct rproc_subdev *subdev, bool crashed)
+{
+	struct scp_subdev_core *subdev_core = to_subdev_core(subdev);
+	struct mtk_scp *scp_dual;
+
+	scp_dual = scp_dual_get(subdev_core->main_scp);
+	if (!scp_dual)
+		return;
+
+	rproc_shutdown(scp_dual->rproc);
+	scp_dual_put(scp_dual);
+}
+
+static void scp_dual_wdt_handler(struct mtk_scp *scp, u32 scp_to_host)
+{
+	struct mtk_scp *scp_dual;
+
+	scp_dual = scp_dual_get(scp);
+	if (!scp_dual)
+		return;
+
+	dev_err(scp_dual->dev, "SCP watchdog timeout! 0x%x\n", scp_to_host);
+	rproc_report_crash(scp_dual->rproc, RPROC_WATCHDOG);
+	scp_dual_put(scp_dual);
+}
+
+static struct rproc_subdev *scp_dual_create_subdev(struct mtk_scp *scp)
+{
+	struct device *dev = scp->dev;
+	struct scp_subdev_core *subdev_core;
+	struct device_node *np;
+
+	np = of_parse_phandle(dev->of_node, "mediatek,scp-core", 0);
+	if (!np)
+		return NULL;
+
+	of_node_put(np);
+
+	subdev_core = devm_kzalloc(dev, sizeof(*subdev_core), GFP_KERNEL);
+	if (!subdev_core)
+		return NULL;
+
+	subdev_core->main_scp = scp;
+	subdev_core->scp_dual_wdt_timeout = scp_dual_wdt_handler;
+	subdev_core->subdev.start = scp_dual_rproc_start;
+	subdev_core->subdev.stop = scp_dual_rproc_stop;
+
+	return &subdev_core->subdev;
+}
+
+static void scp_dual_destroy_subdev(struct rproc_subdev *subdev)
+{
+	struct scp_subdev_core *subdev_core = to_subdev_core(subdev);
+
+	devm_kfree(subdev_core->main_scp->dev, subdev_core);
+}
+
+static void scp_add_dual_subdev(struct mtk_scp *scp)
+{
+	scp->dual_subdev = scp_dual_create_subdev(scp);
+
+	if (scp->dual_subdev)
+		rproc_add_subdev(scp->rproc, scp->dual_subdev);
+}
+
+static void scp_remove_dual_subdev(struct mtk_scp *scp)
+{
+	if (scp->dual_subdev) {
+		rproc_remove_subdev(scp->rproc, scp->dual_subdev);
+		scp_dual_destroy_subdev(scp->dual_subdev);
+		scp->dual_subdev = NULL;
+	}
+}
+
 static int scp_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1014,6 +1133,9 @@ static int scp_probe(struct platform_device *pdev)
 
 	scp_add_rpmsg_subdev(scp);
 
+	if (core_id == SCP_CORE_0)
+		scp_add_dual_subdev(scp);
+
 	ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0), NULL,
 					scp_irq_handler, IRQF_ONESHOT,
 					pdev->name, scp);
@@ -1023,6 +1145,12 @@ static int scp_probe(struct platform_device *pdev)
 		goto remove_subdev;
 	}
 
+	/* disable auto boot before register rproc.
+	 * scp core 1 is booted as a subdevice of scp core 0.
+	 */
+	if (core_id == SCP_CORE_1)
+		rproc->auto_boot = false;
+
 	ret = rproc_add(rproc);
 	if (ret)
 		goto remove_subdev;
@@ -1030,6 +1158,7 @@ static int scp_probe(struct platform_device *pdev)
 	return 0;
 
 remove_subdev:
+	scp_remove_dual_subdev(scp);
 	scp_remove_rpmsg_subdev(scp);
 	scp_ipi_unregister(scp, SCP_IPI_INIT);
 release_dev_mem:
@@ -1047,6 +1176,7 @@ static int scp_remove(struct platform_device *pdev)
 	int i;
 
 	rproc_del(scp->rproc);
+	scp_remove_dual_subdev(scp);
 	scp_remove_rpmsg_subdev(scp);
 	scp_ipi_unregister(scp, SCP_IPI_INIT);
 	scp_unmap_memory_region(scp);
-- 
2.18.0