[PATCH V2 4/5] coresight: etm4x: Change etm4_platform_driver driver for MMIO devices
Anshuman Khandual
anshuman.khandual at arm.com
Tue May 16 04:36:54 PDT 2023
On 3/27/23 20:24, Suzuki K Poulose wrote:
> On 27/03/2023 06:05, 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 at linaro.org>
>> Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
>> Cc: Mike Leach <mike.leach at linaro.org>
>> Cc: Leo Yan <leo.yan at linaro.org>
>> Cc: coresight at lists.linaro.org
>> Cc: linux-arm-kernel at lists.infradead.org
>> Cc: linux-kernel at vger.kernel.org
>> Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
>> ---
>> .../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 3521838ab4fb..bef205023bbe 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>
>> @@ -1067,12 +1068,22 @@ static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata,
>> return true;
>> }
>> +static bool is_etm4x_devtype(void __iomem *base)
>> +{
>> + u32 devtype = readl(base + TRCDEVTYPE);
>> +
>> + return (devtype == ETM_DEVTYPE_ETMv4x_ARCH);
>> +}
>> +
>> static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata,
>> struct csdev_access *csa)
>> {
>> u32 devarch = readl_relaxed(drvdata->base + TRCDEVARCH);
>> u32 idr1 = readl_relaxed(drvdata->base + TRCIDR1);
>> + if (!is_coresight_device(drvdata->base) || !is_etm4x_devtype(drvdata->base))
>> + return false;
>> +
>> /*
>> * All ETMs must implement TRCDEVARCH to indicate that
>> * the component is an ETMv4. To support any broken
>> @@ -2133,6 +2144,7 @@ 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;
>> @@ -2140,7 +2152,18 @@ 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);
>> @@ -2186,7 +2209,7 @@ 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 = ETM_DEVTYPE_ETMv4x_ARCH,
>> }
>> };
>> @@ -2244,6 +2267,10 @@ 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);
>> +
>> pm_runtime_disable(&pdev->dev);
>> return ret;
>> }
>> @@ -2284,7 +2311,33 @@ 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[] = {
>> { .compatible = "arm,coresight-etm4x-sysreg" },
>> { .compatible = "arm,embedded-trace-extension" },
>> {}
>> @@ -2295,8 +2348,9 @@ static struct platform_driver etm4_platform_driver = {
>> .remove = etm4_remove_platform_dev,
>> .driver = {
>> .name = "coresight-etm4x",
>> - .of_match_table = etm4_sysreg_match,
>> + .of_match_table = etm4_match,
>> .suppress_bind_attrs = true,
>> + .pm = &etm4_dev_pm_ops,
>> },
>> };
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
>> index 434f4e95ee17..78dfe7949548 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
>> @@ -701,6 +701,8 @@
>> #define ETM_DEVARCH_ETE_ARCH \
>> (ETM_DEVARCH_ARCHITECT_ARM | ETM_DEVARCH_ARCHID_ETE | ETM_DEVARCH_PRESENT)
>> +#define ETM_DEVTYPE_ETMv4x_ARCH 0x00000013
>
> This has nothing to do with ETMv4 ARCH. This indicates :
>
> [3:0] == 0x3 -> Indicates CoreSight Source
> [7:4] == 0x1 -> Generates PE trace
>
> So, we could call it : CS_DEVTYPE_PE_TRACE, but not ETMv4x
Sure, will rename it as suggested.
>
> Rest looks good to me.
>
> Suzuki
>
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