coresight: catu: Move ACPI support from AMBA driver to platform driver

Add support for the catu devices in a new 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. But first this renames and then refactors catu_probe()
and catu_remove(), making sure it can be used both for platform and AMBA
drivers. This also moves pm_runtime_put() from catu_probe() to the callers.

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
Acked-by: Sudeep Holla <sudeep.holla@arm.com> # For ACPI related changes
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20240314055843.2625883-8-anshuman.khandual@arm.com

drivers/acpi/arm64/amba.c

@@ -27,7 +27,6 @@ static const struct acpi_device_id amba_id_list[] = {
 	{"ARMHC503", 0}, /* ARM CoreSight Debug */
 	{"ARMHC979", 0}, /* ARM CoreSight TPIU */
 	{"ARMHC97C", 0}, /* ARM CoreSight SoC-400 TMC, SoC-600 ETF/ETB */
-	{"ARMHC9CA", 0}, /* ARM CoreSight CATU */
 	{"", 0},
 };
 

drivers/hwtracing/coresight/coresight-catu.c

@@ -7,11 +7,13 @@
  * Author: Suzuki K Poulose <suzuki.poulose@arm.com>
  */
 
+#include <linux/acpi.h>
 #include <linux/amba/bus.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 
 #include "coresight-catu.h"
@@ -502,28 +504,20 @@ static const struct coresight_ops catu_ops = {
 	.helper_ops = &catu_helper_ops,
 };
 
-static int catu_probe(struct amba_device *adev, const struct amba_id *id)
+static int __catu_probe(struct device *dev, struct resource *res)
 {
 	int ret = 0;
 	u32 dma_mask;
-	struct catu_drvdata *drvdata;
+	struct catu_drvdata *drvdata = dev_get_drvdata(dev);
 	struct coresight_desc catu_desc;
 	struct coresight_platform_data *pdata = NULL;
-	struct device *dev = &adev->dev;
 	void __iomem *base;
 
 	catu_desc.name = coresight_alloc_device_name(&catu_devs, dev);
 	if (!catu_desc.name)
 		return -ENOMEM;
 
-	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
-	if (!drvdata) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	dev_set_drvdata(dev, drvdata);
-	base = devm_ioremap_resource(dev, &adev->res);
+	base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(base)) {
 		ret = PTR_ERR(base);
 		goto out;
@@ -567,19 +561,39 @@ static int catu_probe(struct amba_device *adev, const struct amba_id *id)
 	drvdata->csdev = coresight_register(&catu_desc);
 	if (IS_ERR(drvdata->csdev))
 		ret = PTR_ERR(drvdata->csdev);
-	else
-		pm_runtime_put(&adev->dev);
 out:
 	return ret;
 }
 
-static void catu_remove(struct amba_device *adev)
+static int catu_probe(struct amba_device *adev, const struct amba_id *id)
 {
-	struct catu_drvdata *drvdata = dev_get_drvdata(&adev->dev);
+	struct catu_drvdata *drvdata;
+	int ret;
+
+	drvdata = devm_kzalloc(&adev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	amba_set_drvdata(adev, drvdata);
+	ret = __catu_probe(&adev->dev, &adev->res);
+	if (!ret)
+		pm_runtime_put(&adev->dev);
+
+	return ret;
+}
+
+static void __catu_remove(struct device *dev)
+{
+	struct catu_drvdata *drvdata = dev_get_drvdata(dev);
 
 	coresight_unregister(drvdata->csdev);
 }
 
+static void catu_remove(struct amba_device *adev)
+{
+	__catu_remove(&adev->dev);
+}
+
 static struct amba_id catu_ids[] = {
 	CS_AMBA_ID(0x000bb9ee),
 	{},
@@ -598,13 +612,99 @@ static struct amba_driver catu_driver = {
 	.id_table			= catu_ids,
 };
 
+static int catu_platform_probe(struct platform_device *pdev)
+{
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	struct catu_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;
+
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	dev_set_drvdata(&pdev->dev, drvdata);
+	ret = __catu_probe(&pdev->dev, res);
+	pm_runtime_put(&pdev->dev);
+	if (ret) {
+		pm_runtime_disable(&pdev->dev);
+		if (!IS_ERR_OR_NULL(drvdata->pclk))
+			clk_put(drvdata->pclk);
+	}
+
+	return ret;
+}
+
+static int catu_platform_remove(struct platform_device *pdev)
+{
+	struct catu_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
+
+	if (WARN_ON(!drvdata))
+		return -ENODEV;
+
+	__catu_remove(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	if (!IS_ERR_OR_NULL(drvdata->pclk))
+		clk_put(drvdata->pclk);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int catu_runtime_suspend(struct device *dev)
+{
+	struct catu_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
+		clk_disable_unprepare(drvdata->pclk);
+	return 0;
+}
+
+static int catu_runtime_resume(struct device *dev)
+{
+	struct catu_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
+		clk_prepare_enable(drvdata->pclk);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops catu_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(catu_runtime_suspend, catu_runtime_resume, NULL)
+};
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id catu_acpi_ids[] = {
+	{"ARMHC9CA", 0, 0, 0}, /* ARM CoreSight CATU */
+	{},
+};
+
+MODULE_DEVICE_TABLE(acpi, catu_acpi_ids);
+#endif
+
+static struct platform_driver catu_platform_driver = {
+	.probe	= catu_platform_probe,
+	.remove	= catu_platform_remove,
+	.driver	= {
+		.name			= "coresight-catu-platform",
+		.acpi_match_table	= ACPI_PTR(catu_acpi_ids),
+		.suppress_bind_attrs	= true,
+		.pm			= &catu_dev_pm_ops,
+	},
+};
+
 static int __init catu_init(void)
 {
 	int ret;
 
-	ret = amba_driver_register(&catu_driver);
-	if (ret)
-		pr_info("Error registering catu driver\n");
+	ret = coresight_init_driver("catu", &catu_driver, &catu_platform_driver);
 	tmc_etr_set_catu_ops(&etr_catu_buf_ops);
 	return ret;
 }
@@ -612,7 +712,7 @@ static int __init catu_init(void)
 static void __exit catu_exit(void)
 {
 	tmc_etr_remove_catu_ops();
-	amba_driver_unregister(&catu_driver);
+	coresight_remove_driver(&catu_driver, &catu_platform_driver);
 }
 
 module_init(catu_init);

drivers/hwtracing/coresight/coresight-catu.h

@@ -61,6 +61,7 @@
 #define CATU_IRQEN_OFF		0x0
 
 struct catu_drvdata {
+	struct clk *pclk;
 	void __iomem *base;
 	struct coresight_device *csdev;
 	int irq;