[PATCH i-g-t v2] tests/intel/xe_pm: Introduce i2c subtests

[Heikki Krogerus]

On Sat, Jul 19, 2025 at 10:01:01PM +0530, Raag Jadav wrote:
> Introduce subtests for i2c adapter which is used to control on-board
> OEM sensors on selected devices. This will test D3hot/D3cold transition
> after i2c adapter access for the devices that support it.
> 
> v2: Define macros for AMC constants (Lucas)
>     s/index/adapter (Lucas)
> 
> Signed-off-by: Raag Jadav <raag.jadav at intel.com>

Looks good to me. FWIW:

Reviewed-by: Heikki Krogerus <heikki.krogerus at linux.intel.com>

> ---
>  tests/intel/xe_pm.c | 98 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 98 insertions(+)
> 
> diff --git a/tests/intel/xe_pm.c b/tests/intel/xe_pm.c
> index 16b5fc686..ca935d518 100644
> --- a/tests/intel/xe_pm.c
> +++ b/tests/intel/xe_pm.c
> @@ -11,12 +11,18 @@
>   * Test category: functionality test
>   */
>  
> +#include <dirent.h>
>  #include <limits.h>
>  #include <fcntl.h>
>  #include <string.h>
> +#include <sys/ioctl.h>
> +
> +#include <linux/i2c-dev.h>
> +#include <linux/i2c.h>
>  
>  #include "igt.h"
>  #include "lib/igt_device.h"
> +#include "lib/igt_kmod.h"
>  #include "lib/igt_pm.h"
>  #include "lib/igt_sysfs.h"
>  #include "lib/igt_syncobj.h"
> @@ -38,6 +44,10 @@
>  #define PREFETCH (0x1 << 1)
>  #define UNBIND_ALL (0x1 << 2)
>  
> +/* AMC slave details */
> +#define I2C_AMC_ADDR	0x40
> +#define I2C_AMC_REG	0x00
> +
>  enum mem_op {
>  	READ,
>  	WRITE,
> @@ -779,6 +789,87 @@ static void test_mocs_suspend_resume(device_t device, enum igt_suspend_state s_s
>  	}
>  }
>  
> +static int find_i2c_adapter(device_t device, int sysfs_fd)
> +{
> +	int adapter_fd, i2c_adapter = -1;
> +	struct dirent *dirent;
> +	char adapter[32];
> +	DIR *dir;
> +
> +	/* Make sure the /dev/i2c-* files exist */
> +	igt_require(igt_kmod_load("i2c-dev", NULL) == 0);
> +
> +	snprintf(adapter, sizeof(adapter), "%s.%hu", "device/i2c_designware",
> +		 (device.pci_xe->bus << 8) | (device.pci_xe->dev));
> +	adapter_fd = openat(sysfs_fd, adapter, O_RDONLY);
> +	igt_require_fd(adapter_fd);
> +
> +	dir = fdopendir(adapter_fd);
> +	igt_assert(dir);
> +
> +	/* Find the i2c adapter */
> +	while ((dirent = readdir(dir))) {
> +		if (strncmp(dirent->d_name, "i2c-", 4) == 0) {
> +			sscanf(dirent->d_name, "i2c-%d", &i2c_adapter);
> +			break;
> +		}
> +	}
> +
> +	closedir(dir);
> +	close(adapter_fd);
> +	return i2c_adapter;
> +}
> +
> +/**
> + * SUBTEST: %s-i2c
> + * Description:
> + * 	Validate whether the device is able to suspend after i2c adapter access.
> + * Functionality: pm-d3
> + * GPU requirements: D3 feature should be supported
> + *
> + * arg[1]:
> + *
> + * @d3hot:	d3hot
> + * @d3cold:	d3cold
> + */
> +static bool i2c_test(device_t device, int sysfs_fd)
> +{
> +	uint8_t addr = I2C_AMC_ADDR, reg = I2C_AMC_REG, buf;
> +	int i2c_adapter, i2c_fd;
> +	char i2c_dev[16];
> +	struct i2c_msg msgs[] = {
> +		{
> +			.addr = addr,
> +			.flags = 0,
> +			.len = sizeof(reg),
> +			.buf = &reg,
> +		}, {
> +			.addr = addr,
> +			.flags = I2C_M_RD,
> +			.len = sizeof(buf),
> +			.buf = &buf,
> +		}
> +	};
> +	struct i2c_rdwr_ioctl_data msgset = {
> +		.msgs = msgs,
> +		.nmsgs = ARRAY_SIZE(msgs),
> +	};
> +
> +	i2c_adapter = find_i2c_adapter(device, sysfs_fd);
> +	igt_assert_lte(0, i2c_adapter);
> +
> +	snprintf(i2c_dev, sizeof(i2c_dev), "/dev/i2c-%hd", i2c_adapter);
> +	i2c_fd = open(i2c_dev, O_RDWR);
> +	igt_assert_fd(i2c_fd);
> +
> +	/* Perform an i2c transaction to trigger adapter wake */
> +	igt_info("Accessing slave 0x%hhx on %s\n", addr, i2c_dev);
> +	igt_assert_lte(0, igt_ioctl(i2c_fd, I2C_RDWR, &msgset));
> +
> +	close(i2c_fd);
> +	return true;
> +}
> +
>  igt_main
>  {
>  	device_t device;
> @@ -889,6 +980,13 @@ igt_main
>  			cleanup_d3(device);
>  		}
>  
> +		igt_subtest_f("%s-i2c", d->name) {
> +			igt_assert(setup_d3(device, d->state));
> +			igt_assert(i2c_test(device, sysfs_fd));
> +			igt_assert(in_d3(device, d->state));
> +			cleanup_d3(device);
> +		}
> +
>  		igt_subtest_f("%s-multiple-execs", d->name) {
>  			igt_assert(setup_d3(device, d->state));
>  			test_exec(device, 16, 32, NO_SUSPEND, d->state, 0);
> -- 
> 2.34.1

-- 
heikki