Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
From:   Anshuman Khandual <anshuman.khandual@arm.com>
To:     linux-arm-kernel@lists.infradead.org, suzuki.poulose@arm.com
Cc:     Anshuman Khandual <anshuman.khandual@arm.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        James Clark <james.clark@arm.com>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
        coresight@lists.linaro.org,
        linux-stm32@st-md-mailman.stormreply.com
Subject: [PATCH 5/7] coresight: tmc: Move ACPI support from AMBA driver to platform driver
Date:   Fri, 27 Oct 2023 12:59:41 +0530
Message-Id: <20231027072943.3418997-6-anshuman.khandual@arm.com>
In-Reply-To: <20231027072943.3418997-1-anshuman.khandual@arm.com>
References: <20231027072943.3418997-1-anshuman.khandual@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Add support for the tmc devices in the platform driver, which can then be
used on ACPI based platforms. This change would now allow runtime power
management for ACPI based systems. The driver would try to enable the APB
clock if available.

Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: James Clark <james.clark@arm.com>
Cc: linux-acpi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: coresight@lists.linaro.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/acpi/arm64/amba.c                     |   2 -
 .../hwtracing/coresight/coresight-tmc-core.c  | 127 +++++++++++++++---
 drivers/hwtracing/coresight/coresight-tmc.h   |   1 +
 3 files changed, 113 insertions(+), 17 deletions(-)

diff --git a/drivers/acpi/arm64/amba.c b/drivers/acpi/arm64/amba.c
index 8e1783166c33..6980502b7868 100644
--- a/drivers/acpi/arm64/amba.c
+++ b/drivers/acpi/arm64/amba.c
@@ -22,10 +22,8 @@
 static const struct acpi_device_id amba_id_list[] = {
 	{"ARMH0061", 0}, /* PL061 GPIO Device */
 	{"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
-	{"ARMHC501", 0}, /* ARM CoreSight ETR */
 	{"ARMHC502", 0}, /* ARM CoreSight STM */
 	{"ARMHC503", 0}, /* ARM CoreSight Debug */
-	{"ARMHC97C", 0}, /* ARM CoreSight SoC-400 TMC, SoC-600 ETF/ETB */
 	{"", 0},
 };
 
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 7ec5365e2b64..618bc0b7a1a5 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -24,6 +24,8 @@
 #include <linux/of.h>
 #include <linux/coresight.h>
 #include <linux/amba/bus.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
 
 #include "coresight-priv.h"
 #include "coresight-tmc.h"
@@ -437,24 +439,17 @@ static u32 tmc_etr_get_max_burst_size(struct device *dev)
 	return burst_size;
 }
 
-static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
+static int __tmc_probe(struct device *dev, struct resource *res, void *dev_caps)
 {
 	int ret = 0;
 	u32 devid;
 	void __iomem *base;
-	struct device *dev = &adev->dev;
 	struct coresight_platform_data *pdata = NULL;
-	struct tmc_drvdata *drvdata;
-	struct resource *res = &adev->res;
+	struct tmc_drvdata *drvdata = dev_get_drvdata(dev);
 	struct coresight_desc desc = { 0 };
 	struct coresight_dev_list *dev_list = NULL;
 
 	ret = -ENOMEM;
-	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
-	if (!drvdata)
-		goto out;
-
-	dev_set_drvdata(dev, drvdata);
 
 	/* Validity for the resource is already checked by the AMBA core */
 	base = devm_ioremap_resource(dev, res);
@@ -497,8 +492,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 		desc.type = CORESIGHT_DEV_TYPE_SINK;
 		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM;
 		desc.ops = &tmc_etr_cs_ops;
-		ret = tmc_etr_setup_caps(dev, devid,
-					 coresight_get_uci_data(id));
+		ret = tmc_etr_setup_caps(dev, devid, dev_caps);
 		if (ret)
 			goto out;
 		idr_init(&drvdata->idr);
@@ -530,7 +524,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 		ret = PTR_ERR(pdata);
 		goto out;
 	}
-	adev->dev.platform_data = pdata;
+	dev->platform_data = pdata;
 	desc.pdata = pdata;
 
 	drvdata->csdev = coresight_register(&desc);
@@ -546,11 +540,23 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 	if (ret)
 		coresight_unregister(drvdata->csdev);
 	else
-		pm_runtime_put(&adev->dev);
+		pm_runtime_put(dev);
 out:
 	return ret;
 }
 
+static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	struct tmc_drvdata *drvdata;
+
+	drvdata = devm_kzalloc(&adev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	amba_set_drvdata(adev, drvdata);
+	return __tmc_probe(&adev->dev, &adev->res, coresight_get_uci_data(id));
+}
+
 static void tmc_shutdown(struct amba_device *adev)
 {
 	unsigned long flags;
@@ -573,9 +579,9 @@ static void tmc_shutdown(struct amba_device *adev)
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 }
 
-static void tmc_remove(struct amba_device *adev)
+static void __tmc_remove(struct device *dev)
 {
-	struct tmc_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+	struct tmc_drvdata *drvdata = dev_get_drvdata(dev);
 
 	/*
 	 * Since misc_open() holds a refcount on the f_ops, which is
@@ -586,6 +592,11 @@ static void tmc_remove(struct amba_device *adev)
 	coresight_unregister(drvdata->csdev);
 }
 
+static void tmc_remove(struct amba_device *adev)
+{
+	__tmc_remove(&adev->dev);
+}
+
 static const struct amba_id tmc_ids[] = {
 	CS_AMBA_ID(0x000bb961),
 	/* Coresight SoC 600 TMC-ETR/ETS */
@@ -613,6 +624,92 @@ static struct amba_driver tmc_driver = {
 
 module_amba_driver(tmc_driver);
 
+static int tmc_platform_probe(struct platform_device *pdev)
+{
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	struct tmc_drvdata *drvdata;
+	int ret = 0;
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->pclk = coresight_get_enable_apb_pclk(&pdev->dev);
+	if (IS_ERR(drvdata->pclk))
+		return -ENODEV;
+
+	if (res) {
+		drvdata->base = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(drvdata->base)) {
+			clk_put(drvdata->pclk);
+			return PTR_ERR(drvdata->base);
+		}
+	}
+
+	dev_set_drvdata(&pdev->dev, drvdata);
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = __tmc_probe(&pdev->dev, res, NULL);
+	if (ret) {
+		pm_runtime_put_noidle(&pdev->dev);
+		pm_runtime_disable(&pdev->dev);
+	}
+	return ret;
+}
+
+static int tmc_platform_remove(struct platform_device *pdev)
+{
+	__tmc_remove(&pdev->dev);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int tmc_runtime_suspend(struct device *dev)
+{
+	struct tmc_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata->pclk && !IS_ERR_OR_NULL(drvdata->pclk))
+		clk_disable_unprepare(drvdata->pclk);
+	return 0;
+}
+
+static int tmc_runtime_resume(struct device *dev)
+{
+	struct tmc_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata->pclk && !IS_ERR_OR_NULL(drvdata->pclk))
+		clk_prepare_enable(drvdata->pclk);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops tmc_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(tmc_runtime_suspend, tmc_runtime_resume, NULL)
+};
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id tmc_acpi_ids[] = {
+	{"ARMHC501", 0}, /* ARM CoreSight ETR */
+	{"ARMHC97C", 0}, /* ARM CoreSight SoC-400 TMC, SoC-600 ETF/ETB */
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, tmc_acpi_ids);
+#endif
+
+static struct platform_driver tmc_platform_driver = {
+	.probe	= tmc_platform_probe,
+	.remove	= tmc_platform_remove,
+	.driver	= {
+		.name			= "coresight-tmc-platform",
+		.acpi_match_table	= ACPI_PTR(tmc_acpi_ids),
+		.suppress_bind_attrs	= true,
+		.pm			= &tmc_dev_pm_ops,
+	},
+};
+module_platform_driver(tmc_platform_driver);
+
 MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
 MODULE_DESCRIPTION("Arm CoreSight Trace Memory Controller driver");
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 8dcb426ac3e7..d52bc2eeed8d 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -190,6 +190,7 @@ struct etr_buf {
  * @perf_buf:	PERF buffer for ETR.
  */
 struct tmc_drvdata {
+	struct clk		*pclk;
 	void __iomem		*base;
 	struct coresight_device	*csdev;
 	struct miscdevice	miscdev;
-- 
2.25.1