Re: [PATCH v9 2/5] soc: qcom: Add SoC sleep stats driver

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Mon 06 Sep 00:28 CDT 2021, Maulik Shah wrote:

> From: Mahesh Sivasubramanian <msivasub@codeaurora.org>
> 
> Let's add a driver to read the stats from remote processor and
> export to debugfs.
> 
> The driver creates "qcom_sleep_stats" directory in debugfs and
> adds files for various low power mode available. Below is sample
> output with command
> 
> cat /sys/kernel/debug/qcom_sleep_stats/ddr
> count = 0
> Last Entered At = 0
> Last Exited At = 0
> Accumulated Duration = 0
> 
> Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
> Signed-off-by: Lina Iyer <ilina@codeaurora.org>
> [mkshah: add subsystem sleep stats, create one file for each stat]
> Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
> ---
>  drivers/soc/qcom/Kconfig           |  10 ++
>  drivers/soc/qcom/Makefile          |   1 +
>  drivers/soc/qcom/soc_sleep_stats.c | 241 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 252 insertions(+)
>  create mode 100644 drivers/soc/qcom/soc_sleep_stats.c
> 
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index 79b568f..e80b63a 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -190,6 +190,16 @@ config QCOM_SOCINFO
>  	 Say yes here to support the Qualcomm socinfo driver, providing
>  	 information about the SoC to user space.
>  
> +config QCOM_SOC_SLEEP_STATS
> +	tristate "Qualcomm Technologies, Inc. (QTI) SoC sleep stats driver"
> +	depends on ARCH_QCOM && DEBUG_FS || COMPILE_TEST
> +	depends on QCOM_SMEM
> +	help
> +	  Qualcomm Technologies, Inc. (QTI) SoC sleep stats driver to read
> +	  the shared memory exported by the remote processor related to
> +	  various SoC level low power modes statistics and export to debugfs
> +	  interface.
> +
>  config QCOM_WCNSS_CTRL
>  	tristate "Qualcomm WCNSS control driver"
>  	depends on ARCH_QCOM || COMPILE_TEST
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index ad675a6..5f30d74 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
>  obj-$(CONFIG_QCOM_SMP2P)	+= smp2p.o
>  obj-$(CONFIG_QCOM_SMSM)	+= smsm.o
>  obj-$(CONFIG_QCOM_SOCINFO)	+= socinfo.o
> +obj-$(CONFIG_QCOM_SOC_SLEEP_STATS)	+= soc_sleep_stats.o

I know that the rest of the modules here does a bad job and have
completely generic names, but could we rename this "qcom_sleep_stats"
instead?

>  obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
>  obj-$(CONFIG_QCOM_APR) += apr.o
>  obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
> diff --git a/drivers/soc/qcom/soc_sleep_stats.c b/drivers/soc/qcom/soc_sleep_stats.c
[..]
> +static int qcom_soc_sleep_stats_probe(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	void __iomem *reg;
> +	struct dentry *root;
> +	const struct stats_config *config;
> +	struct stats_data *d;
> +	int i;
> +
> +	config = device_get_match_data(&pdev->dev);
> +	if (!config)
> +		return -ENODEV;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return PTR_ERR(res);

You no longer use this "res".

> +
> +	reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
> +	if (!reg)

IS_ERR()

> +		return -ENOMEM;
> +
> +	d = devm_kcalloc(&pdev->dev, config->num_records,
> +			 sizeof(*d), GFP_KERNEL);
> +	if (!d)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < config->num_records; i++)
> +		d[i].appended_stats_avail = config->appended_stats_avail;
> +
> +	root = debugfs_create_dir("qcom_sleep_stats", NULL);
> +
> +	qcom_create_subsystem_stat_files(root);
> +	qcom_create_soc_sleep_stat_files(root, reg, d, config->num_records);
> +
> +	platform_set_drvdata(pdev, root);
> +
> +	return 0;
> +}
> +
> +static int qcom_soc_sleep_stats_remove(struct platform_device *pdev)
> +{
> +	struct dentry *root = platform_get_drvdata(pdev);
> +
> +	debugfs_remove_recursive(root);
> +
> +	return 0;
> +}
> +
> +static const struct stats_config rpm_data = {
> +	.num_records = 2,
> +	.appended_stats_avail = true,
> +};
> +
> +static const struct stats_config rpmh_data = {
> +	.num_records = 3,
> +	.appended_stats_avail = false,
> +};
> +
> +static const struct of_device_id qcom_soc_sleep_stats_table[] = {
> +	{ .compatible = "qcom,rpm-sleep-stats", .data = &rpm_data },
> +	{ .compatible = "qcom,rpmh-sleep-stats", .data = &rpmh_data },
> +	{ }
> +};

MODULE_DEVICE_TABLE(of, qcom_soc_sleep_stats_table);

Otherwise the module doesn't load automatically.

Regards,
Bjorn

> +
> +static struct platform_driver soc_sleep_stats = {
> +	.probe = qcom_soc_sleep_stats_probe,
> +	.remove = qcom_soc_sleep_stats_remove,
> +	.driver = {
> +		.name = "soc_sleep_stats",
> +		.of_match_table = qcom_soc_sleep_stats_table,
> +	},
> +};
> +module_platform_driver(soc_sleep_stats);
> +
> +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. (QTI) SoC Sleep Stats driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>