Re: [PATCH 4/6] drivers: perf: samsung: Add PPMU driver support

[Krzysztof Kozlowski <krzk@kernel.org>]

On 08/07/2025 12:32, Vivek Yadav wrote:
> +static struct platform_driver samsung_ppmu_driver = {
> +	.probe = samsung_ppmu_probe,
> +	.remove = samsung_ppmu_remove,
> +	.driver	= {
> +		.name = "samsung-ppmu",
> +		.of_match_table	= ppmu_of_match,
> +	},
> +};
> +
> +module_platform_driver(samsung_ppmu_driver);
> +
> +MODULE_ALIAS("perf:samsung-ppmu");

No, drop. What's with these aliases from samsung... second try today.
From where do you get such code?

> +MODULE_DESCRIPTION("Samsung Platform Performance Measuring Unit (PPMU) driver");
> +MODULE_AUTHOR("Vivek Yadav <vivek.2311@samsung.com>");
> +MODULE_AUTHOR("Ravi Patel <ravi.patel@samsung.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/perf/samsung/ppmu_platform.c b/drivers/perf/samsung/ppmu_platform.c
> new file mode 100644
> index 000000000000..ee11311d5a61
> --- /dev/null
> +++ b/drivers/perf/samsung/ppmu_platform.c
> @@ -0,0 +1,338 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Samsung Platform Performance Measuring Unit (PPMU) core file
> + *
> + * Copyright (c) 2024-25 Samsung Electronics Co., Ltd.
> + *
> + * Authors: Vivek Yadav <vivek.2311@samsung.com>
> + *          Ravi Patel <ravi.patel@samsung.com>
> + */
> +
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/perf_event.h>
> +#include "samsung_ppmu.h"
> +
> +/*
> + * PMU format attributes
> + */
> +ssize_t samsung_ppmu_format_sysfs_show(struct device *dev,
> +				       struct device_attribute *attr, char *buf)
> +{
> +	struct dev_ext_attribute *eattr;
> +
> +	eattr = container_of(attr, struct dev_ext_attribute, attr);
> +
> +	return sysfs_emit(buf, "%s\n", (char *)eattr->var);
> +}
> +EXPORT_SYMBOL_GPL(samsung_ppmu_format_sysfs_show);

1. Where did you document ABI?
2. This is not used. You have one module, not two. Drop all exports.

3. You need to clearly explain what is wrong with existing drivers in a
very detailed way, before you start posting another (possibly
duplicated) drivers.


Best regards,
Krzysztof