Re: [PATCH V3] acpi:apd:add AMD ACPI2Platform device support for x86 system.

[Andy Shevchenko]

On Tue, Feb 3, 2015 at 3:54 AM, Ken Xue <Ken.Xue@xxxxxxx> wrote:
> This new feature is to interpret AMD specific ACPI device to
> platform device such as I2C, UART found on AMD CZ and later chipsets. It
> based on example intel LPSS. Now, it can support AMD I2C & UART.
>

Few minor things below.
Be free to fix in depend on what Mika and Rafael confirm.

Anyway,
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> Signed-off-by: Ken Xue <Ken.Xue@xxxxxxx>
> ---
>  arch/x86/Kconfig        |  11 +++
>  drivers/acpi/Makefile   |   2 +-
>  drivers/acpi/acpi_apd.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/acpi/internal.h |   2 +
>  drivers/acpi/scan.c     |   1 +
>  5 files changed, 216 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/acpi/acpi_apd.c
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 0dc9d01..ddf8d42 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -496,6 +496,17 @@ config X86_INTEL_LPSS
>           things like clock tree (common clock framework) and pincontrol
>           which are needed by the LPSS peripheral drivers.
>
> +config X86_AMD_PLATFORM_DEVICE
> +       bool "AMD ACPI2Platform devices support"
> +       depends on ACPI
> +       select COMMON_CLK
> +       select PINCTRL
> +       ---help---
> +         Select to interpret AMD specific ACPI device to platform device
> +         such as I2C, UART found on AMD Carrizo and later chipsets. Selecting
> +         this option enables things like clock tree (common clock framework)
> +         and pinctrl.

Sounds 'like' is redundant here. It explicitly enables common clock
and pin control frameworks.

> +
>  config IOSF_MBI
>         tristate "Intel SoC IOSF Sideband support for SoC platforms"
>         depends on PCI
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index f74317c..0071141 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -40,7 +40,7 @@ acpi-$(CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC) += processor_pdc.o
>  acpi-y                         += ec.o
>  acpi-$(CONFIG_ACPI_DOCK)       += dock.o
>  acpi-y                         += pci_root.o pci_link.o pci_irq.o
> -acpi-y                         += acpi_lpss.o
> +acpi-y                         += acpi_lpss.o acpi_apd.o
>  acpi-y                         += acpi_platform.o
>  acpi-y                         += acpi_pnp.o
>  acpi-y                         += int340x_thermal.o
> diff --git a/drivers/acpi/acpi_apd.c b/drivers/acpi/acpi_apd.c
> new file mode 100644
> index 0000000..b27bc1c
> --- /dev/null
> +++ b/drivers/acpi/acpi_apd.c
> @@ -0,0 +1,201 @@
> +/*
> + * AMD ACPI support for ACPI2platform device.
> + *
> + * Copyright (c) 2014,2015 AMD Corporation.
> + * Authors: Ken Xue <Ken.Xue@xxxxxxx>
> + *     Wu, Jeff <Jeff.Wu@xxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/clkdev.h>
> +#include <linux/acpi.h>
> +#include <linux/err.h>
> +#include <linux/clk.h>
> +#include <linux/pm.h>
> +
> +#include "internal.h"
> +
> +ACPI_MODULE_NAME("acpi_apd");
> +struct apd_private_data;
> +
> +/**

/*, or use description on per flag basis.

> + * device flags of acpi_apd_dev_desc.
> + * ACPI_APD_SYSFS : add device attributes in sysfs
> + * ACPI_APD_PM : attach power domain to device
> + * ACPI_APD_PM_ON : power on device when attach power domain
> + */
> +#define ACPI_APD_SYSFS BIT(0)
> +#define ACPI_APD_PM    BIT(1)
> +#define ACPI_APD_PM_ON BIT(2)
> +
> +/**
> + * struct apd_device_desc - a descriptor for apd device
> + * @flags: device flags like ACPI_APD_SYSFS ACPI_APD_PM ACPI_APD_PM_ON

%ACPI_APD_SYSFS, %ACPI_APD_PM, %ACPI_APD_APM_ON.

Could it be combination? State this explicitly.

> + * @fixed_clk_rate: fixed rate input clock source for acpi device;
> + *                     0 means no fixed rate input clock source
> + * @setup: a hook routine to set device resource during create platform device
> + *
> + * device description defined as acpi_device_id.driver_data

d -> D

> + */
> +struct apd_device_desc {
> +       unsigned int flags;
> +       unsigned int fixed_clk_rate;
> +       int (*setup)(struct apd_private_data *pdata);
> +};
> +
> +struct apd_private_data {
> +       struct clk *clk;
> +       struct acpi_device *adev;
> +       const struct apd_device_desc *dev_desc;
> +};
> +
> +#ifdef CONFIG_X86_AMD_PLATFORM_DEVICE
> +#define APD_ADDR(desc) ((unsigned long)&desc)
> +
> +static int acpi_apd_setup(struct apd_private_data *pdata)
> +{
> +       const struct apd_device_desc *dev_desc = pdata->dev_desc;
> +       struct clk *clk = ERR_PTR(-ENODEV);
> +
> +       if (dev_desc->fixed_clk_rate) {
> +               clk = clk_register_fixed_rate(&pdata->adev->dev,
> +                                       dev_name(&pdata->adev->dev),
> +                                       NULL, CLK_IS_ROOT,
> +                                       dev_desc->fixed_clk_rate);
> +               clk_register_clkdev(clk, NULL, dev_name(&pdata->adev->dev));
> +               pdata->clk = clk;
> +       }

What about
if (!âclk_rate)
 return 0;
â
return 0; ?

And question why we need int to be returned at all?

> +
> +       return 0;
> +}
> +
> +static struct apd_device_desc cz_i2c_desc = {
> +       .setup = acpi_apd_setup,
> +       .fixed_clk_rate = 133000000,
> +};
> +
> +static struct apd_device_desc cz_uart_desc = {
> +       .setup = acpi_apd_setup,
> +       .fixed_clk_rate = 48000000,
> +};
> +
> +#else
> +
> +#define APD_ADDR(desc) (0UL)
> +
> +#endif /* CONFIG_X86_AMD_PLATFORM_DEVICE */
> +
> +static int acpi_apd_create_device(struct acpi_device *adev,
> +                                  const struct acpi_device_id *id)
> +{
> +       const struct apd_device_desc *dev_desc;
> +       struct apd_private_data *pdata;
> +       struct platform_device *pdev;
> +       int ret;
> +
> +       dev_desc = (struct apd_device_desc *)id->driver_data;

You may move this assignment to the definition block. And if it
doesn't fit one line you may cast to (void *), though I don't know if
Rafael likes such trick.

> +       if (!dev_desc) {
> +               pdev = acpi_create_platform_device(adev);
> +               return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;

I guess it worth to add a comment what means return code here.

> +       }
> +       pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
> +       if (!pdata)
> +               return -ENOMEM;
> +
> +       pdata->adev = adev;
> +       pdata->dev_desc = dev_desc;
> +
> +       if (dev_desc->setup) {
> +               ret = dev_desc->setup(pdata);
> +               if (ret)
> +                       goto err_out;
> +       }
> +
> +       adev->driver_data = pdata;
> +       pdev = acpi_create_platform_device(adev);
> +       if (!IS_ERR_OR_NULL(pdev))
> +               return 1;
> +
> +       ret = PTR_ERR(pdev);
> +       adev->driver_data = NULL;
> +
> + err_out:
> +       kfree(pdata);
> +       return ret;
> +}
> +
> +static const struct acpi_device_id acpi_apd_device_ids[] = {
> +       /* Generic apd devices */
> +       { "AMD0010", APD_ADDR(cz_i2c_desc) },
> +       { "AMD0020", APD_ADDR(cz_uart_desc) },
> +       { }
> +};
> +
> +#ifdef CONFIG_X86_AMD_PLATFORM_DEVICE
> +static int acpi_apd_platform_notify(struct notifier_block *nb,
> +                                    unsigned long action, void *data)
> +{
> +       struct platform_device *pdev = to_platform_device(data);
> +       const struct acpi_device_id *id = NULL;

Redundant assignment.

> +       struct apd_private_data *pdata;
> +       struct acpi_device *adev;
> +       bool power_on;
> +       int ret;
> +
> +       id = acpi_match_device(acpi_apd_device_ids, &pdev->dev);
> +       if (!id || !id->driver_data)
> +               return 0;
> +
> +       if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))

Better of course to do like
status = â
if (status) [don't remember how to check status with ACPI API]
 return 0;

> +               return 0;
> +
> +       pdata = acpi_driver_data(adev);
> +       if (!pdata || !pdata->dev_desc)
> +               return 0;
> +
> +       switch (action) {
> +       case BUS_NOTIFY_ADD_DEVICE:
> +               if (pdata->dev_desc->flags & ACPI_APD_PM) {
> +                       power_on = !!(pdata->dev_desc->flags & ACPI_APD_PM_ON);
> +                       ret = dev_pm_domain_attach(&pdev->dev, power_on);
> +
> +                       if (ret)
> +                               dev_dbg(&pdev->dev,
> +                               "failed to attached pm domain (%d)\n", ret);
> +               }
> +               break;
> +       case BUS_NOTIFY_DEL_DEVICE:
> +               if (pdata->dev_desc->flags & ACPI_APD_PM) {
> +                       power_on = !!(pdata->dev_desc->flags & ACPI_APD_PM_ON);
> +                       dev_pm_domain_detach(&pdev->dev, power_on);
> +               }
> +               break;
> +       }
> +
> +       return 0;
> +}
> +
> +static struct notifier_block acpi_apd_nb = {
> +       .notifier_call = acpi_apd_platform_notify,
> +};
> +#endif
> +
> +static struct acpi_scan_handler apd_handler = {
> +       .ids = acpi_apd_device_ids,
> +       .attach = acpi_apd_create_device,
> +};
> +
> +void __init acpi_apd_init(void)
> +{
> +#ifdef CONFIG_X86_AMD_PLATFORM_DEVICE
> +       bus_register_notifier(&platform_bus_type, &acpi_apd_nb);
> +#endif
> +
> +       acpi_scan_add_handler(&apd_handler);
> +}
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 163e82f..c24ae9d 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -68,6 +68,8 @@ static inline void acpi_debugfs_init(void) { return; }
>  #endif
>  void acpi_lpss_init(void);
>
> +void acpi_apd_init(void);
> +
>  acpi_status acpi_hotplug_schedule(struct acpi_device *adev, u32 src);
>  bool acpi_queue_hotplug_work(struct work_struct *work);
>  void acpi_device_hotplug(struct acpi_device *adev, u32 src);
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index dc4d896..bbca783 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2544,6 +2544,7 @@ int __init acpi_scan_init(void)
>         acpi_pci_link_init();
>         acpi_processor_init();
>         acpi_lpss_init();
> +       acpi_apd_init();
>         acpi_cmos_rtc_init();
>         acpi_container_init();
>         acpi_memory_hotplug_init();
> --
> 1.9.1
>
>
>



-- 
With Best Regards,
Andy Shevchenko
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