diff options
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-core.c')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-core.c | 54 |
1 files changed, 52 insertions, 2 deletions
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index fa758cc21827..3267192f0c1c 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -3,6 +3,8 @@ * Copyright (c) 2012, The Linux Foundation. All rights reserved. */ +#include <linux/acpi.h> +#include <linux/bitfield.h> #include <linux/build_bug.h> #include <linux/kernel.h> #include <linux/init.h> @@ -1374,8 +1376,9 @@ struct coresight_device *coresight_register(struct coresight_desc *desc) goto out_unlock; } - if (csdev->type == CORESIGHT_DEV_TYPE_SINK || - csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) { + if ((csdev->type == CORESIGHT_DEV_TYPE_SINK || + csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) && + sink_ops(csdev)->alloc_buffer) { ret = etm_perf_add_symlink_sink(csdev); if (ret) { @@ -1698,6 +1701,53 @@ int coresight_etm_get_trace_id(struct coresight_device *csdev, enum cs_mode mode } EXPORT_SYMBOL_GPL(coresight_etm_get_trace_id); +/* + * Attempt to find and enable programming clock (pclk) and trace clock (atclk) + * for the given device. + * + * For ACPI devices, clocks are controlled by firmware, so bail out early in + * this case. Also, skip enabling pclk if the clock is managed by the AMBA + * bus driver instead. + * + * atclk is an optional clock, it will be only enabled when it is existed. + * Otherwise, a NULL pointer will be returned to caller. + * + * Returns: '0' on Success; Error code otherwise. + */ +int coresight_get_enable_clocks(struct device *dev, struct clk **pclk, + struct clk **atclk) +{ + WARN_ON(!pclk); + + if (has_acpi_companion(dev)) + return 0; + + if (!dev_is_amba(dev)) { + /* + * "apb_pclk" is the default clock name for an Arm Primecell + * peripheral, while "apb" is used only by the CTCU driver. + * + * For easier maintenance, CoreSight drivers should use + * "apb_pclk" as the programming clock name. + */ + *pclk = devm_clk_get_optional_enabled(dev, "apb_pclk"); + if (!*pclk) + *pclk = devm_clk_get_optional_enabled(dev, "apb"); + if (IS_ERR(*pclk)) + return PTR_ERR(*pclk); + } + + /* Initialization of atclk is skipped if it is a NULL pointer. */ + if (atclk) { + *atclk = devm_clk_get_optional_enabled(dev, "atclk"); + if (IS_ERR(*atclk)) + return PTR_ERR(*atclk); + } + + return 0; +} +EXPORT_SYMBOL_GPL(coresight_get_enable_clocks); + MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>"); MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>"); |