Add support for the stm 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: Maxime Coquelin mcoquelin.stm32@gmail.com Cc: Alexandre Torgue alexandre.torgue@foss.st.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 Cc: linux-stm32@st-md-mailman.stormreply.com Tested-by: Sudeep Holla sudeep.holla@arm.com # Boot and driver probe only Acked-by: Sudeep Holla sudeep.holla@arm.com # For ACPI related changes Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com --- Changes in V3:
- Added commnets for 'drvdata->pclk' - Used coresight_init_driver()/coresight_remove_driver() helpers instead - Dropped pm_runtime_put() from __stm_probe() - Added pm_runtime_put() on success path in stm_probe() - Added pm_runtime_put() on success/error paths in stm_platform_probe()
drivers/acpi/arm64/amba.c | 1 - drivers/hwtracing/coresight/coresight-stm.c | 101 ++++++++++++++++++-- 2 files changed, 91 insertions(+), 11 deletions(-)
diff --git a/drivers/acpi/arm64/amba.c b/drivers/acpi/arm64/amba.c index d3c1defa7bc8..bec0976541da 100644 --- a/drivers/acpi/arm64/amba.c +++ b/drivers/acpi/arm64/amba.c @@ -22,7 +22,6 @@ static const struct acpi_device_id amba_id_list[] = { {"ARMH0061", 0}, /* PL061 GPIO Device */ {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */ - {"ARMHC502", 0}, /* ARM CoreSight STM */ {"ARMHC503", 0}, /* ARM CoreSight Debug */ {"", 0}, }; diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c index 9cdca4f86cab..a5f1da1e230e 100644 --- a/drivers/hwtracing/coresight/coresight-stm.c +++ b/drivers/hwtracing/coresight/coresight-stm.c @@ -29,6 +29,8 @@ #include <linux/perf_event.h> #include <linux/pm_runtime.h> #include <linux/stm.h> +#include <linux/platform_device.h> +#include <linux/acpi.h>
#include "coresight-priv.h" #include "coresight-trace-id.h" @@ -115,6 +117,7 @@ DEFINE_CORESIGHT_DEVLIST(stm_devs, "stm"); * struct stm_drvdata - specifics associated to an STM component * @base: memory mapped base address for this component. * @atclk: optional clock for the core parts of the STM. + * @pclk: APB clock if present, otherwise NULL * @csdev: component vitals needed by the framework. * @spinlock: only one at a time pls. * @chs: the channels accociated to this STM. @@ -132,6 +135,7 @@ DEFINE_CORESIGHT_DEVLIST(stm_devs, "stm"); struct stm_drvdata { void __iomem *base; struct clk *atclk; + struct clk *pclk; struct coresight_device *csdev; spinlock_t spinlock; struct channel_space chs; @@ -816,14 +820,12 @@ static char *stm_csdev_name(struct coresight_device *csdev) return uci_data ? (char *)uci_data : "STM"; }
-static int stm_probe(struct amba_device *adev, const struct amba_id *id) +static int __stm_probe(struct device *dev, struct resource *res) { int ret, trace_id; void __iomem *base; - struct device *dev = &adev->dev; struct coresight_platform_data *pdata = NULL; struct stm_drvdata *drvdata; - struct resource *res = &adev->res; struct resource ch_res; struct coresight_desc desc = { 0 };
@@ -835,12 +837,16 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id) if (!drvdata) return -ENOMEM;
- drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */ + drvdata->atclk = devm_clk_get(dev, "atclk"); /* optional */ if (!IS_ERR(drvdata->atclk)) { ret = clk_prepare_enable(drvdata->atclk); if (ret) return ret; } + + drvdata->pclk = coresight_get_enable_apb_pclk(dev); + if (IS_ERR(drvdata->pclk)) + return -ENODEV; dev_set_drvdata(dev, drvdata);
base = devm_ioremap_resource(dev, res); @@ -888,7 +894,7 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id) ret = PTR_ERR(pdata); goto stm_unregister; } - adev->dev.platform_data = pdata; + dev->platform_data = pdata;
desc.type = CORESIGHT_DEV_TYPE_SOURCE; desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE; @@ -909,8 +915,6 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id) } drvdata->traceid = (u8)trace_id;
- pm_runtime_put(&adev->dev); - dev_info(&drvdata->csdev->dev, "%s initialized\n", stm_csdev_name(drvdata->csdev)); return 0; @@ -923,9 +927,20 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id) return ret; }
-static void stm_remove(struct amba_device *adev) +static int stm_probe(struct amba_device *adev, const struct amba_id *id) +{ + int ret; + + ret = __stm_probe(&adev->dev, &adev->res); + if (!ret) + pm_runtime_put(&adev->dev); + + return ret; +} + +static void __stm_remove(struct device *dev) { - struct stm_drvdata *drvdata = dev_get_drvdata(&adev->dev); + struct stm_drvdata *drvdata = dev_get_drvdata(dev);
coresight_trace_id_put_system_id(drvdata->traceid); coresight_unregister(drvdata->csdev); @@ -933,6 +948,11 @@ static void stm_remove(struct amba_device *adev) stm_unregister_device(&drvdata->stm); }
+static void stm_remove(struct amba_device *adev) +{ + __stm_remove(&adev->dev); +} + #ifdef CONFIG_PM static int stm_runtime_suspend(struct device *dev) { @@ -941,6 +961,8 @@ static int stm_runtime_suspend(struct device *dev) if (drvdata && !IS_ERR(drvdata->atclk)) clk_disable_unprepare(drvdata->atclk);
+ if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk)) + clk_disable_unprepare(drvdata->pclk); return 0; }
@@ -951,6 +973,8 @@ static int stm_runtime_resume(struct device *dev) if (drvdata && !IS_ERR(drvdata->atclk)) clk_prepare_enable(drvdata->atclk);
+ if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk)) + clk_prepare_enable(drvdata->pclk); return 0; } #endif @@ -979,7 +1003,64 @@ static struct amba_driver stm_driver = { .id_table = stm_ids, };
-module_amba_driver(stm_driver); +static int stm_platform_probe(struct platform_device *pdev) +{ + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + int ret = 0; + + pm_runtime_get_noresume(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + ret = __stm_probe(&pdev->dev, res); + pm_runtime_put(&pdev->dev); + + return ret; +} + +static int stm_platform_remove(struct platform_device *pdev) +{ + struct stm_drvdata *drvdata = dev_get_drvdata(&pdev->dev); + + if (drvdata) + __stm_remove(&pdev->dev); + + pm_runtime_disable(&pdev->dev); + if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk)) + clk_put(drvdata->pclk); + return 0; +} + +#ifdef CONFIG_ACPI +static const struct acpi_device_id stm_acpi_ids[] = { + {"ARMHC502", 0}, /* ARM CoreSight STM */ + {}, +}; +MODULE_DEVICE_TABLE(acpi, stm_acpi_ids); +#endif + +static struct platform_driver stm_platform_driver = { + .probe = stm_platform_probe, + .remove = stm_platform_remove, + .driver = { + .name = "coresight-stm-platform", + .acpi_match_table = ACPI_PTR(stm_acpi_ids), + .suppress_bind_attrs = true, + .pm = &stm_dev_pm_ops, + }, +}; + +static int __init stm_init(void) +{ + return coresight_init_driver("stm", &stm_driver, &stm_platform_driver); +} + +static void __exit stm_exit(void) +{ + coresight_remove_driver(&stm_driver, &stm_platform_driver); +} +module_init(stm_init); +module_exit(stm_exit);
MODULE_AUTHOR("Pratik Patel pratikp@codeaurora.org"); MODULE_DESCRIPTION("Arm CoreSight System Trace Macrocell driver");