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Message-ID: <b51c8f75-97f8-604d-cf1a-770cca4078aa@quicinc.com>
Date:   Tue, 30 May 2023 12:21:05 -0700
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Subject: Re: [PATCH v1 1/3] Coresight: Add driver to support for CSR
To:     Mao Jinlong <quic_jinlmao@quicinc.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        "Mike Leach" <mike.leach@linaro.org>, Leo Yan <leo.yan@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
CC:     <coresight@lists.linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <devicetree@vger.kernel.org>,
        Tingwei Zhang <quic_tingweiz@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Tao Zhang <quic_taozha@quicinc.com>,
        Hao Zhang <quic_hazha@quicinc.com>
References: <20230526153508.6208-1-quic_jinlmao@quicinc.com>
 <20230526153508.6208-2-quic_jinlmao@quicinc.com>
Content-Language: en-US
From:   Trilok Soni <quic_tsoni@quicinc.com>
In-Reply-To: <20230526153508.6208-2-quic_jinlmao@quicinc.com>
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Precedence: bulk

On 5/26/2023 8:35 AM, Mao Jinlong wrote:
> This driver provides support for CoreSight Slave Register block
> that hosts miscellaneous configuration registers. Those
> configuration registers can be used to control, various coresight
> configurations.
> 
> Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
> ---
>   drivers/hwtracing/coresight/Kconfig         |  12 ++
>   drivers/hwtracing/coresight/Makefile        |   1 +
>   drivers/hwtracing/coresight/coresight-csr.c | 142 ++++++++++++++++++++
>   drivers/hwtracing/coresight/coresight-csr.h |  54 ++++++++
>   4 files changed, 209 insertions(+)
>   create mode 100644 drivers/hwtracing/coresight/coresight-csr.c
>   create mode 100644 drivers/hwtracing/coresight/coresight-csr.h
> 
> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
> index 2b5bbfffbc4f..e769ea3709d9 100644
> --- a/drivers/hwtracing/coresight/Kconfig
> +++ b/drivers/hwtracing/coresight/Kconfig
> @@ -236,4 +236,16 @@ config CORESIGHT_TPDA
>   
>   	  To compile this driver as a module, choose M here: the module will be
>   	  called coresight-tpda.
> +
> +config CORESIGHT_CSR
> +	tristate "CoreSight Slave Register driver"
> +	help
> +	  This driver provides support for CoreSight Slave Register block
> +	  that hosts miscellaneous configuration registers.
> +	  Those configuration registers can be used to control, various
> +	  coresight configurations.
> +
> +	  To compile this driver as a module, choose M here: the module will be
> +	  called coresight-csr.
> +
>   endif
> diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
> index 33bcc3f7b8ae..956c642d05f6 100644
> --- a/drivers/hwtracing/coresight/Makefile
> +++ b/drivers/hwtracing/coresight/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_CORESIGHT_TPDA) += coresight-tpda.o
>   coresight-cti-y := coresight-cti-core.o	coresight-cti-platform.o \
>   		   coresight-cti-sysfs.o
>   obj-$(CONFIG_ULTRASOC_SMB) += ultrasoc-smb.o
> +obj-$(CONFIG_CORESIGHT_CSR) += coresight-csr.o
> diff --git a/drivers/hwtracing/coresight/coresight-csr.c b/drivers/hwtracing/coresight/coresight-csr.c
> new file mode 100644
> index 000000000000..a1403e8531ee
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-csr.c
> @@ -0,0 +1,142 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/slab.h>
> +
> +#include "coresight-priv.h"
> +#include "coresight-csr.h"
> +
> +DEFINE_CORESIGHT_DEVLIST(csr_devs, "csr");
> +
> +static LIST_HEAD(csr_list);
> +
> +/*
> + * Get the CSR by name.
> + */
> +struct coresight_csr *coresight_csr_get(const char *name)
> +{
> +	struct coresight_csr *csr;
> +
> +	list_for_each_entry(csr, &csr_list, link) {
> +		if (!strcmp(csr->name, name))
> +			return csr;
> +	}
> +	return ERR_PTR(-EINVAL);
> +}
> +EXPORT_SYMBOL(coresight_csr_get);

EXPORT_SYMBOL_GPL everywhere in this driver please.

> +
> +/*
> + * Get the device node's name from device tree.
> + */
> +int of_get_coresight_csr_name(struct device_node *node, const char **csr_name)
> +{
> +	struct device_node *csr_node;
> +
> +	csr_node = of_parse_phandle(node, "coresight-csr", 0);
> +	if (!csr_node)
> +		return -EINVAL;
> +
> +	*csr_name = csr_node->full_name;
> +	of_node_put(csr_node);
> +	return 0;
> +}
> +EXPORT_SYMBOL(of_get_coresight_csr_name);

---Trilok Soni