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Message-ID: <20864469.6Ozf1NSibZ@vostro.rjw.lan>
Date: Mon, 24 Nov 2014 02:15:35 +0100
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Ken Xue <Ken.Xue@....com>
Cc: lenb@...nel.org, linux-acpi@...r.kernel.org,
linux-kernel@...r.kernel.org, Jeff Wu <Jeff.Wu@....com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
Andriy Shevchenko <andriy.shevchenko@...el.com>
Subject: Re: [PATCH] acpi:apd:add AMD ACPI2Platform device support for x86 system.
On Tuesday, November 18, 2014 01:58:11 PM Ken Xue 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 is based on example
> INTEL LPSS. Now, it can support AMD I2C & UART.
>
> Signed-off-by: Ken Xue <Ken.Xue@....com>
> Signed-off-by: Jeff Wu <Jeff.Wu@....com>
Generally speaking, this seems to duplicate much code from acpi_lpss which
should be re-used instead. What about moving the code that will be common
between acpi_lpss and the new driver into a new file (say acpi_soc.c)?
Also, you need to avoid automatic creation of platform devices when
!X86_AMD_PLATFORM_DEVICE in analogy with what acpi_lpss does, or bad things
will happen.
> ---
> arch/x86/Kconfig | 11 +++
> drivers/acpi/Makefile | 1 +
> drivers/acpi/acpi_apd.c | 245 ++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/acpi/internal.h | 6 ++
> drivers/acpi/scan.c | 1 +
> 5 files changed, 264 insertions(+)
> create mode 100644 drivers/acpi/acpi_apd.c
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index ded8a67..6402c79f 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -495,6 +495,17 @@ 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 chipset. Selecting
> + this option enables things like clock tree (common clock framework)
> + and pinctrl.
> +
> 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 c3b2fcb..91fc1c2 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -41,6 +41,7 @@ acpi-y += ec.o
> acpi-$(CONFIG_ACPI_DOCK) += dock.o
> acpi-y += pci_root.o pci_link.o pci_irq.o
> acpi-y += acpi_lpss.o
> +acpi-$(CONFIG_X86_AMD_PLATFORM_DEVICE) += 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..994b7db
> --- /dev/null
> +++ b/drivers/acpi/acpi_apd.c
> @@ -0,0 +1,245 @@
> +/*
> + * AMD ACPI support for ACPI2platform device.
> + *
> + * Copyright (c) 2014, AMD Corporation.
> + * Authors: Ken Xue <Ken.Xue@....com>
> + * Jeff Wu <Jeff.Wu@....com>
> + *
> + * 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/acpi.h>
> +#include <linux/clk.h>
> +#include <linux/clkdev.h>
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "internal.h"
> +
> +ACPI_MODULE_NAME("acpi_apd");
> +struct apd_private_data;
> +
> +struct apd_device_desc {
> + bool clk_required;
> + bool fixed_root_clock;
> + const char *clk_name;
> + unsigned long rate;
> + size_t prv_size_override;
> + void (*setup)(struct apd_private_data *pdata);
> +};
> +
> +struct apd_private_data {
> + void __iomem *mmio_base;
> + resource_size_t mmio_size;
> + struct clk *clk;
> + const struct apd_device_desc *dev_desc;
> +};
> +
> +static struct apd_device_desc amd_i2c_desc = {
> + .clk_required = true,
> + .fixed_root_clock = true,
> + .clk_name = "i2c_clk",
> + .rate = 133000000, /*(133 * 1000 * 1000)*/
> +};
> +
> +static struct apd_device_desc amd_uart_desc = {
> + .clk_required = true,
> + .fixed_root_clock = true,
> + .clk_name = "uart_clk",
> + .rate = 48000000,
> +};
> +
> +static const struct acpi_device_id acpi_apd_device_ids[] = {
> + /* Generic apd devices */
> + { "AMD0010", (unsigned long)&amd_i2c_desc },
> + { "AMD0020", (unsigned long)&amd_uart_desc },
> + { }
> +};
> +
> +static int is_memory(struct acpi_resource *res, void *not_used)
> +{
> + struct resource r;
> +
> + return !acpi_dev_resource_memory(res, &r);
> +}
> +
> +static int register_device_clock(struct acpi_device *adev,
> + struct apd_private_data *pdata)
> +{
> + const struct apd_device_desc *dev_desc = pdata->dev_desc;
> + struct clk *clk = ERR_PTR(-ENODEV);
> +
> + clk = pdata->clk;
> + if (!clk && dev_desc->fixed_root_clock) {
> + clk = clk_register_fixed_rate(&adev->dev, dev_name(&adev->dev),
> + NULL, CLK_IS_ROOT, dev_desc->rate);
> + pdata->clk = clk;
> + clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
> + }
> +
> + return 0;
> +}
> +
> +static int acpi_apd_create_device(struct acpi_device *adev,
> + const struct acpi_device_id *id)
> +{
> + struct apd_device_desc *dev_desc;
> + struct apd_private_data *pdata;
> + struct resource_list_entry *rentry;
> + struct list_head resource_list;
> + struct platform_device *pdev;
> + int ret;
> +
> + dev_desc = (struct apd_device_desc *)id->driver_data;
> + if (!dev_desc) {
> + pdev = acpi_create_platform_device(adev);
> + return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
> + }
> +
> + pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
> + if (!pdata)
> + return -ENOMEM;
> +
> + INIT_LIST_HEAD(&resource_list);
> + ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
> + if (ret < 0)
> + goto err_out;
> +
> + list_for_each_entry(rentry, &resource_list, node)
> + if (resource_type(&rentry->res) == IORESOURCE_MEM) {
> + if (dev_desc->prv_size_override)
> + pdata->mmio_size = dev_desc->prv_size_override;
> + else
> + pdata->mmio_size = resource_size(&rentry->res);
> + pdata->mmio_base = ioremap(rentry->res.start,
> + pdata->mmio_size);
> + break;
> + }
> +
> + acpi_dev_free_resource_list(&resource_list);
> +
> + pdata->dev_desc = dev_desc;
> +
> + if (dev_desc->clk_required) {
> + ret = register_device_clock(adev, pdata);
> + if (ret) {
> + /* Skip the device, but continue the namespace scan. */
> + ret = 0;
> + goto err_out;
> + }
> + }
> +
> + /*
> + * This works around a known issue in ACPI tables where apd devices
> + * have _PS0 and _PS3 without _PSC (and no power resources), so
> + * acpi_bus_init_power() will assume that the BIOS has put them into D0.
> + */
> + ret = acpi_device_fix_up_power(adev);
> + if (ret) {
> + /* Skip the device, but continue the namespace scan. */
> + ret = 0;
> + goto err_out;
> + }
> +
> + if (dev_desc->setup)
> + dev_desc->setup(pdata);
> +
> + adev->driver_data = pdata;
> + pdev = acpi_create_platform_device(adev);
> + if (!IS_ERR_OR_NULL(pdev)) {
> + device_enable_async_suspend(&pdev->dev);
> + return ret;
> + }
> +
> + ret = PTR_ERR(pdev);
> + adev->driver_data = NULL;
> +
> + err_out:
> + kfree(pdata);
> + return ret;
> +}
> +
> +static ssize_t apd_device_desc_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int ret;
> + struct acpi_device *adev;
> + struct apd_private_data *pdata;
> +
> + ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
> + if (WARN_ON(ret))
> + return ret;
> +
> + pdata = acpi_driver_data(adev);
> + if (WARN_ON(!pdata || !pdata->dev_desc))
> + return -ENODEV;
> +
> + if (pdata->dev_desc->clk_required)
> + return sprintf(buf, "Required clk: %s %s %ld\n",
> + pdata->dev_desc->clk_name,
> + pdata->dev_desc->fixed_root_clock ?
> + "fix rate" : "no fix rate",
> + pdata->dev_desc->rate);
> + else
> + return sprintf(buf, "No need clk\n");
> +}
> +
> +static DEVICE_ATTR(device_desc, S_IRUSR, apd_device_desc_show, NULL);
> +
> +static struct attribute *apd_attrs[] = {
> + &dev_attr_device_desc.attr,
> + NULL,
> +};
> +
> +static struct attribute_group apd_attr_group = {
> + .attrs = apd_attrs,
> + .name = "apd_ltr",
> +};
> +
> +static int acpi_apd_platform_notify(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
> + struct platform_device *pdev = to_platform_device(data);
> + struct apd_private_data *pdata;
> + struct acpi_device *adev;
> + const struct acpi_device_id *id;
> + int ret = 0;
> +
> + 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))
> + return 0;
> +
> + pdata = acpi_driver_data(adev);
> + if (!pdata || !pdata->mmio_base)
> + return 0;
> +
> + if (action == BUS_NOTIFY_ADD_DEVICE)
> + ret = sysfs_create_group(&pdev->dev.kobj, &apd_attr_group);
> + else if (action == BUS_NOTIFY_DEL_DEVICE)
> + sysfs_remove_group(&pdev->dev.kobj, &apd_attr_group);
> +
> + return ret;
> +}
> +
> +static struct notifier_block acpi_apd_nb = {
> + .notifier_call = acpi_apd_platform_notify,
> +};
> +
> +static struct acpi_scan_handler apd_handler = {
> + .ids = acpi_apd_device_ids,
> + .attach = acpi_apd_create_device,
> +};
> +
> +void __init acpi_apd_init(void)
> +{
> + bus_register_notifier(&platform_bus_type, &acpi_apd_nb);
> + acpi_scan_add_handler(&apd_handler);
> +}
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 447f6d6..c8a0e8e 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -68,6 +68,12 @@ static inline void acpi_debugfs_init(void) { return; }
> #endif
> void acpi_lpss_init(void);
>
> +#ifdef CONFIG_X86_AMD_PLATFORM_DEVICE
> +void acpi_apd_init(void);
> +#else
> +static inline void acpi_apd_init(void) {}
> +#endif
> +
> 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 0476e90..24fef2b 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -2349,6 +2349,7 @@ 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();
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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