On 5/19/23 18:14, Suzuki K Poulose wrote:
> On 19/05/2023 06:21, Anshuman Khandual wrote:
>> Add support for handling MMIO based devices via platform driver. We need to
>> make sure that :
>>
>> 1) The APB clock, if present is enabled at probe and via runtime_pm ops
>> 2) Use the ETM4x architecture or CoreSight architecture registers to
>> identify a device as CoreSight ETM4x, instead of relying a white list of
>> "Peripheral IDs"
>>
>> The driver doesn't get to handle the devices yet, until we wire the ACPI
>> changes to move the devices to be handled via platform driver than the
>> etm4_amba driver.
>>
>> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>> Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
>> Cc: Mike Leach <mike.leach@xxxxxxxxxx>
>> Cc: Leo Yan <leo.yan@xxxxxxxxxx>
>> Cc: coresight@xxxxxxxxxxxxxxxx
>> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
>> ---
>> .../coresight/coresight-etm4x-core.c | 62 +++++++++++++++++--
>> drivers/hwtracing/coresight/coresight-etm4x.h | 4 ++
>> include/linux/coresight.h | 47 ++++++++++++++
>> 3 files changed, 109 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> index 914ef6eb85d1..807b3a5a0eda 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> @@ -30,6 +30,7 @@
>> #include <linux/platform_device.h>
>> #include <linux/pm_runtime.h>
>> #include <linux/property.h>
>> +#include <linux/clk/clk-conf.h>
>> #include <asm/barrier.h>
>> #include <asm/sections.h>
>> @@ -1073,11 +1074,21 @@ static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata,
>> return true;
>> }
>> +static bool is_devtype_cpu_trace(void __iomem *base)
>> +{
>> + u32 devtype = readl(base + TRCDEVTYPE);
>> +
>> + return (devtype == CS_DEVTYPE_PE_TRACE);
>> +}
>> +
>> static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata,
>> struct csdev_access *csa)
>> {
>> u32 devarch = readl_relaxed(drvdata->base + TRCDEVARCH);
>> + if (!is_coresight_device(drvdata->base) || !is_devtype_cpu_trace(drvdata->base))
>> + return false;
>> +
>> /*
>> * All ETMs must implement TRCDEVARCH to indicate that
>> * the component is an ETMv4. Even though TRCIDR1 also
>> @@ -2135,6 +2146,7 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
>> static int etm4_probe_platform_dev(struct platform_device *pdev)
>> {
>> + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> struct etmv4_drvdata *drvdata;
>> int ret;
>> @@ -2142,7 +2154,18 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
>> if (!drvdata)
>> return -ENOMEM;
>> - drvdata->base = NULL;
>> + 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);
>> @@ -2188,7 +2211,7 @@ static struct amba_cs_uci_id uci_id_etm4[] = {
>> /* ETMv4 UCI data */
>> .devarch = ETM_DEVARCH_ETMv4x_ARCH,
>> .devarch_mask = ETM_DEVARCH_ID_MASK,
>> - .devtype = 0x00000013,
>> + .devtype = CS_DEVTYPE_PE_TRACE,
>> }
>> };
>> @@ -2246,6 +2269,10 @@ static int __exit etm4_remove_platform_dev(struct platform_device *pdev)
>> if (drvdata)
>> ret = etm4_remove_dev(drvdata);
>> +
>> + if (drvdata->pclk)
>> + clk_put(drvdata->pclk);
>> +
>
> Shouldn't this be done *after* pm_runtime_disable() below ?
Sure, will re-order them.
>
>> pm_runtime_disable(&pdev->dev);
>
>> return ret;
>> }
>> @@ -2286,7 +2313,33 @@ static struct amba_driver etm4x_amba_driver = {
>> .id_table = etm4_ids,
>> };
>> -static const struct of_device_id etm4_sysreg_match[] = {
>> +#ifdef CONFIG_PM
>> +static int etm4_runtime_suspend(struct device *dev)
>> +{
>> + struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
>> +
>> + if (!IS_ERR(drvdata->pclk))
>> + clk_disable_unprepare(drvdata->pclk);
>> +
>> + return 0;
>> +}
>> +
>> +static int etm4_runtime_resume(struct device *dev)
>> +{
>> + struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
>> +
>> + if (!IS_ERR(drvdata->pclk))
>> + clk_prepare_enable(drvdata->pclk);
>> +
>> + return 0;
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops etm4_dev_pm_ops = {
>> + SET_RUNTIME_PM_OPS(etm4_runtime_suspend, etm4_runtime_resume, NULL)
>> +};
>> +
>> +static const struct of_device_id etm4_match[] = {
>
> minor nit: This is still only for the system instruction based
> etms, so this renaming is going to confuse. Please leave it
> unchanged.
Sure.
