linux-kernel - Re: [PATCH v3 1/3] platform/x86: intel_pmc_core: Convert to a platform

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Date:   Mon, 8 Apr 2019 19:51:41 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Rajat Jain <rajatja@...gle.com>
Cc:     Rajneesh Bhardwaj <rajneesh.bhardwaj@...el.com>,
        Vishwanath Somayaji <vishwanath.somayaji@...el.com>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Platform Driver <platform-driver-x86@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Wysocki@...gle.com, Rafael J <rafael.j.wysocki@...el.com>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        furquan@...gle.com, evgreen@...gle.com,
        Rajat Jain <rajatxjain@...il.com>
Subject: Re: [PATCH v3 1/3] platform/x86: intel_pmc_core: Convert to a platform_driver

On Fri, Apr 5, 2019 at 11:36 PM Rajat Jain <rajatja@...gle.com> wrote:
>
> Convert the intel_pmc_core driver to a platform driver, and attach using
> the ACPI enumeration method (via the ACPI device "INT33A1").
>
> Signed-off-by: Rajat Jain <rajatja@...gle.com>

> -static const struct x86_cpu_id intel_pmc_core_ids[] = {
> -       INTEL_CPU_FAM6(SKYLAKE_MOBILE, spt_reg_map),
> -       INTEL_CPU_FAM6(SKYLAKE_DESKTOP, spt_reg_map),
> -       INTEL_CPU_FAM6(KABYLAKE_MOBILE, spt_reg_map),
> -       INTEL_CPU_FAM6(KABYLAKE_DESKTOP, spt_reg_map),
> -       INTEL_CPU_FAM6(CANNONLAKE_MOBILE, cnp_reg_map),
> -       INTEL_CPU_FAM6(ICELAKE_MOBILE, icl_reg_map),
> -       {}
> -};
> -
> -MODULE_DEVICE_TABLE(x86cpu, intel_pmc_core_ids);
> -

> +static int pmc_core_probe(struct platform_device *pdev)
>  {
> +       static bool device_initialized;
>         struct pmc_dev *pmcdev = &pmc;
> -       const struct x86_cpu_id *cpu_id;
>         u64 slp_s0_addr;
>         int err;
>
> -       cpu_id = x86_match_cpu(intel_pmc_core_ids);
> -       if (!cpu_id)
> +       if (device_initialized)
>                 return -ENODEV;
>
> -       pmcdev->map = (struct pmc_reg_map *)cpu_id->driver_data;

> +       switch (boot_cpu_data.x86_model) {

I didn't get why this should be boot CPU?
Otherwise, leave the structure and leave the x86_match_cpu() call.

> +       case INTEL_FAM6_SKYLAKE_MOBILE:
> +       case INTEL_FAM6_SKYLAKE_DESKTOP:
> +       case INTEL_FAM6_KABYLAKE_MOBILE:
> +       case INTEL_FAM6_KABYLAKE_DESKTOP:
>
> -       /*
> -        * Coffeelake has CPU ID of Kabylake and Cannonlake PCH. So here
> -        * Sunrisepoint PCH regmap can't be used. Use Cannonlake PCH regmap
> -        * in this case.
> -        */
> -       if (pmcdev->map == &spt_reg_map && !pci_dev_present(pmc_pci_ids))
> +               pmcdev->map = &spt_reg_map;
> +
> +               /*
> +                * Special case: Coffeelake has CPU ID of Kabylake, but has
> +                * Cannonlake PCH. So need to use cnp_reg_map instead of
> +                * spt_reg_map for this special case. The PMC core PCI device
> +                * on Coffeelake is hidden, so use that as the deciding factor.
> +                */
> +               if (!pci_dev_present(pmc_pci_ids))
> +                       pmcdev->map = &cnp_reg_map;
> +
> +               break;
> +
> +       case INTEL_FAM6_CANNONLAKE_MOBILE:
>                 pmcdev->map = &cnp_reg_map;
> +               break;
> +
> +       case INTEL_FAM6_ICELAKE_MOBILE:
> +               pmcdev->map = &icl_reg_map;
> +               break;
> +       default:
> +               /*
> +                * Which map should we use by default? If not specified
> +                * explicitly, assume Icelake by default for now.
> +                */
> +               pmcdev->map = &icl_reg_map;
> +               break;
> +       }
>
>         if (lpit_read_residency_count_address(&slp_s0_addr))
>                 pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT;
> @@ -890,26 +903,47 @@ static int __init pmc_core_probe(void)
>
>         err = pmc_core_dbgfs_register(pmcdev);
>         if (err < 0) {
> -               pr_warn(" debugfs register failed.\n");
> +               dev_warn(&pdev->dev, "debugfs register failed.\n");
>                 iounmap(pmcdev->regbase);
>                 return err;
>         }
>
>         dmi_check_system(pmc_core_dmi_table);
> -       pr_info(" initialized\n");
> +       platform_set_drvdata(pdev, pmcdev);
> +
> +       dev_info(&pdev->dev, " initialized\n");
> +       device_initialized = true;
> +
>         return 0;
>  }
> -module_init(pmc_core_probe)
>
> -static void __exit pmc_core_remove(void)
> +static int pmc_core_remove(struct platform_device *pdev)
>  {
> -       struct pmc_dev *pmcdev = &pmc;
> +       struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
>
> +       platform_set_drvdata(pdev, NULL);
>         pmc_core_dbgfs_unregister(pmcdev);
>         mutex_destroy(&pmcdev->lock);
>         iounmap(pmcdev->regbase);
> +       return 0;
>  }
> -module_exit(pmc_core_remove)
> +
> +static const struct acpi_device_id pmc_core_acpi_ids[] = {
> +       {"INT33A1", 0}, /* _HID for Intel Power Engine, _CID PNP0D80*/
> +       { }
> +};
> +MODULE_DEVICE_TABLE(acpi, pmc_core_acpi_ids);
> +
> +static struct platform_driver pmc_core_driver = {
> +       .driver = {
> +               .name = "pmc_core",
> +               .acpi_match_table = ACPI_PTR(pmc_core_acpi_ids),
> +       },
> +       .probe = pmc_core_probe,
> +       .remove = pmc_core_remove,
> +};
> +
> +module_platform_driver(pmc_core_driver);
>
>  MODULE_LICENSE("GPL v2");
>  MODULE_DESCRIPTION("Intel PMC Core Driver");
> --
> 2.21.0.392.gf8f6787159e-goog
>


-- 
With Best Regards,
Andy Shevchenko