Message-ID: <1417761286.29484.21.camel@kxue-X58A-UD3R>
Subject: Re: [PATCH 1/2] acpi:soc: merge common codes for creating platform
 device
From: Ken Xue <Ken.Xue@amd.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
CC: <rjw@rjwysocki.net>, <linux-acpi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Date: Fri, 5 Dec 2014 14:34:46 +0800
In-Reply-To: <20141204130424.GM28857@lahna.fi.intel.com>
References: <1417610017-2140-1-git-send-email-Ken.Xue@amd.com>
	 <20141204130424.GM28857@lahna.fi.intel.com>
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Sender: linux-kernel-owner@vger.kernel.org

On Thu, 2014-12-04 at 15:04 +0200, Mika Westerberg wrote:
> On Wed, Dec 03, 2014 at 08:33:37PM +0800, Ken Xue wrote:
> > This patch is supposed to deliver some common codes for AMD APD and
> > INTEL LPSS. It can help to convert some specific acpi devices to be
> > platform devices.
> > 
> > Signed-off-by: Ken Xue <Ken.Xue@amd.com>
> > ---
> >  drivers/acpi/Makefile   |   2 +-
> >  drivers/acpi/acpi_soc.c | 211 ++++++++++++++++++++++++++++++++++++++++++++++++
> >  drivers/acpi/acpi_soc.h |  90 +++++++++++++++++++++
> >  3 files changed, 302 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/acpi/acpi_soc.c
> >  create mode 100644 drivers/acpi/acpi_soc.h
> > 
> > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> > index c3b2fcb..ae3397d 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_soc.o acpi_lpss.o
> 
> I think you need to convert acpi_lpss.c to use this new acpi_soc.c.
> 
[ken] I would like to merge lpss. But you know that I am lack of INTEL
platforms to verify codes before submit. And i am a little worried about
i may not cover so much rich features of lpss well. so, can we merge
lpss after current patch? or what's your plan?

> >  acpi-y				+= acpi_platform.o
> >  acpi-y				+= acpi_pnp.o
> >  acpi-y				+= int340x_thermal.o
> > diff --git a/drivers/acpi/acpi_soc.c b/drivers/acpi/acpi_soc.c
> > new file mode 100644
> > index 0000000..25089a0
> > --- /dev/null
> > +++ b/drivers/acpi/acpi_soc.c
> > @@ -0,0 +1,211 @@
> > +/*
> > + * ACPI SOC support for Intel Lynxpoint LPSS and AMD APD.
> > + *
> > + * Copyright (C) 2015, Intel Corporation & AMD Corporation
> > + * Authors: Ken Xue <Ken.Xue@amd.com>
> > + *		Mika Westerberg <mika.westerberg@linux.intel.com>
> > + *		Rafael J. Wysocki <rafael.j.wysocki@intel.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/err.h>
> > +#include <linux/io.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/pm_runtime.h>
> > +#include <linux/delay.h>
> > +#include <linux/pm_domain.h>
> > +
> > +#include "internal.h"
> > +#include "acpi_soc.h"
> > +
> > +ACPI_MODULE_NAME("acpi_soc");
> > +
> > +/* A list for all acpi soc device */
> > +static LIST_HEAD(a_soc_list);
> > +
> > +static int is_memory(struct acpi_resource *res, void *not_used)
> > +{
> > +	struct resource r;
> > +
> > +	return !acpi_dev_resource_memory(res, &r);
> > +}
> > +
> > +static int acpi_soc_create_device(struct acpi_device *adev,
> > +				   const struct acpi_device_id *id)
> > +{
> > +	struct acpi_soc_dev_desc *dev_desc;
> > +	struct acpi_soc_dev_private_data *pdata;
> > +	struct resource_list_entry *rentry;
> > +	struct list_head resource_list;
> > +	struct platform_device *pdev;
> > +	int ret;
> > +
> > +	dev_desc = (struct acpi_soc_dev_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->mem_size_override)
> > +				pdata->mmio_size = dev_desc->mem_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->adev = adev;
> > +	pdata->dev_desc = dev_desc;
> > +
> > +	if (dev_desc->setup)
> > +		dev_desc->setup(pdata);
> > +
> > +	/*
> > +	 * This works around a known issue in ACPI tables where acpi soc 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;
> > +	}
> > +
> > +	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 int acpi_soc_platform_notify(struct notifier_block *nb,
> > +				     unsigned long action, void *data)
> > +{
> > +	struct platform_device *pdev = to_platform_device(data);
> > +	struct acpi_soc_dev_private_data *pdata;
> > +	struct acpi_device *adev;
> > +	struct acpi_soc *a_soc_entry;
> > +	const struct acpi_device_id *id = NULL;
> > +
> > +	list_for_each_entry(a_soc_entry, &a_soc_list, list) {
> > +		id = acpi_match_device(a_soc_entry->ids, &pdev->dev);
> > +		if (!id)
> > +			break;
> > +	}
> > +
> > +	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;
> > +
> > +	switch (action) {
> > +	case BUS_NOTIFY_BOUND_DRIVER:
> > +		if ((pdata->dev_desc->flags & ACPI_SOC_PM)) {
> > +			if (a_soc_entry->pm_domain)
> > +				pdev->dev.pm_domain = a_soc_entry->pm_domain;
> > +			else if (pdata->dev_desc->flags & ACPI_SOC_PM_ON)
> > +					dev_pm_domain_attach(&pdev->dev, true);
> > +			else
> > +					dev_pm_domain_attach(&pdev->dev, false);
> > +		}
> > +		break;
> > +	case BUS_NOTIFY_UNBOUND_DRIVER:
> > +		if ((pdata->dev_desc->flags & ACPI_SOC_PM)) {
> > +			if (a_soc_entry->pm_domain)
> > +				pdev->dev.pm_domain = a_soc_entry->pm_domain;
> > +			else if (pdata->dev_desc->flags & ACPI_SOC_PM_ON)
> > +					dev_pm_domain_detach(&pdev->dev, true);
> > +			else
> > +					dev_pm_domain_detach(&pdev->dev, false);
> > +		}
> > +		break;
> > +	case BUS_NOTIFY_ADD_DEVICE:
> > +		if ((pdata->dev_desc->flags & ACPI_SOC_SYSFS)
> > +			&& a_soc_entry->pm_domain)
> > +			return sysfs_create_group(&pdev->dev.kobj,
> > +						  a_soc_entry->attr_group);
> > +	case BUS_NOTIFY_DEL_DEVICE:
> > +		if ((pdata->dev_desc->flags & ACPI_SOC_SYSFS)
> > +			&& a_soc_entry->pm_domain)
> > +			sysfs_remove_group(&pdev->dev.kobj,
> > +			a_soc_entry->attr_group);
> > +		break;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static struct notifier_block acpi_soc_nb = {
> > +	.notifier_call = acpi_soc_platform_notify,
> > +};
> > +
> > +static void acpi_soc_bind(struct device *dev)
> > +{
> > +	struct acpi_soc_dev_private_data *pdata;
> > +
> > +	pdata = acpi_driver_data(ACPI_COMPANION(dev));
> > +
> > +	if (!pdata || !pdata->dev_desc || !pdata->dev_desc->bind)
> > +		return;
> > +
> > +	pdata->dev_desc->bind(pdata);
> > +}
> > +
> > +static void acpi_soc_unbind(struct device *dev)
> > +{
> > +	struct acpi_soc_dev_private_data *pdata;
> > +
> > +	pdata = acpi_driver_data(ACPI_COMPANION(dev));
> > +
> > +	if (!pdata || !pdata->dev_desc || !pdata->dev_desc->unbind)
> > +		return;
> > +
> > +	pdata->dev_desc->unbind(pdata);
> > +}
> > +
> > +void register_acpi_soc(struct acpi_soc *a_soc, bool disable_scan_handler)
> 
> Would it work better if we pass acpi_scan_handler as a parameter to this
> function?
> 
> Then if it is NULL, it means that it will not register scan handler at
> all.
> 
> And then provide the default handler in acpi_soc.h so that you can do
> 
> 	register_acpi_soc(&soc, default_acpi_scan_handler);
> 
> or
> 
> 	register_acpi_soc(&soc, NULL);
> 
> depending the case. But also support passing custom scan handler.
> 
[Ken] I add some hooks for acpi_scan_handler in acpi_soc_dev_desc like
"setup" "bind" "unbind" in case of different implementation of platform.
your approach is other good way to same target. Right?

> > +{
> > +	struct acpi_scan_handler *acpi_soc_handler;
> > +
> > +	INIT_LIST_HEAD(&a_soc->list);
> > +	list_add(&a_soc->list, &a_soc_list);
> > +
> > +	acpi_soc_handler = kzalloc(sizeof(*acpi_soc_handler), GFP_KERNEL);
> > +	acpi_soc_handler->ids = a_soc->ids;
> > +	if (!disable_scan_handler) {
> > +		acpi_soc_handler->attach = acpi_soc_create_device;
> > +		acpi_soc_handler->bind = acpi_soc_bind;
> > +		acpi_soc_handler->unbind = acpi_soc_unbind;
> > +	}
> > +	acpi_scan_add_handler(acpi_soc_handler);
> > +	bus_register_notifier(&platform_bus_type, &acpi_soc_nb);
> > +}
> > diff --git a/drivers/acpi/acpi_soc.h b/drivers/acpi/acpi_soc.h
> > new file mode 100644
> > index 0000000..cc270a5
> > --- /dev/null
> > +++ b/drivers/acpi/acpi_soc.h
> > @@ -0,0 +1,90 @@
> > +/*
> > + * ACPI SOC support for Intel Lynxpoint LPSS and AMD APD.
> > + *
> > + * Copyright (C) 2015, Intel Corporation & AMD Corporation
> > + * Authors: Ken Xue <Ken.Xue@amd.com>
> > + *		Mika Westerberg <mika.westerberg@linux.intel.com>
> > + *		Rafael J. Wysocki <rafael.j.wysocki@intel.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.
> > + */
> > +#ifndef _ACPI_SOC_H
> > +#define _ACPI_SOC_H
> > +
> > +#include <linux/acpi.h>
> > +#include <linux/clk.h>
> > +#include <linux/pm.h>
> > +
> > +/* Flags */
> > +#define ACPI_SOC_SYSFS	BIT(0)
> > +#define ACPI_SOC_PM		BIT(1)
> > +#define ACPI_SOC_PM_ON	BIT(2)
> 
> Would be nice to document what those mean.
> 
[Ken] sure. i will add more description.

> > +
> > +struct acpi_soc_dev_private_data;
> > +
> > +/**
> > + * struct acpi_soc - acpi soc
> > + * @list: list head
> > + * @ids: all acpi device ids for acpi soc
> > + * @pm_domain: power domain for all acpi device;can be NULL
> > + * @attr_group: attribute group for sysfs support of acpi soc;can be NULL
> > + */
> > +struct acpi_soc {
> > +	struct list_head list;
> > +	struct acpi_device_id	*ids;
> > +	struct dev_pm_domain	*pm_domain;
> > +	struct attribute_group	*attr_group;
> 
> These are tab aligned but list is using spaces. Please be consistent.
> 
[Ken] got it. 

> > +};
> > +
> > +/**
> > + * struct acpi_soc_dev_desc - a descriptor for acpi device
> > + * @flags: some device feature flags
> 
[Ken] ok.

> Please a bit better documentation than "some device feature flags".
> 
> > + * @clk: clock device
> > + * @fixed_clk_rate: fixed rate input clock source for acpi device;
> > + *				0 means no fixed rate input clock source
> > + * @mem_size_override: a workaround for override device memsize;
> > + *				0 means no needs for this WA
> > + * @setup: a hook routine to set device resource during create platform device
> > + * @bind: a hook of acpi_scan_handler.bind
> > + * @unbind: a hook of acpi_scan_handler.unbind
> > + *
> > + *device description defined as acpi_device_id.driver_data
> 
> Missing space.
> 
[Ken] got it. 

> > + */
> > +struct acpi_soc_dev_desc {
> > +	unsigned int flags;
> > +	struct clk *clk;
> > +	unsigned int fixed_clk_rate;
> > +	size_t mem_size_override;
> > +	int (*setup)(struct acpi_soc_dev_private_data *pdata);
> > +	void (*bind)(struct acpi_soc_dev_private_data *pdata);
> > +	void (*unbind)(struct acpi_soc_dev_private_data *pdata);
> > +};
> > +
> > +/**
> > + * struct acpi_soc_dev_private_data - acpi device private data
> > + * @mmio_base: virtual memory base addr of the device
> > + * @mmio_size: device memory size
> > + * @dev_desc: device description
> > + * @adev: apci device
> 
> apci -> acpi
> 
[Ken] got it. 

> > + */
> > +struct acpi_soc_dev_private_data {
> > +	void __iomem *mmio_base;
> > +	resource_size_t mmio_size;
> > +
> > +	struct acpi_soc_dev_desc *dev_desc;
> > +	struct acpi_device *adev;
> > +};
> > +
> > +/**
> > + * register_acpi_soc - register a new acpi soc
> > + * @a_soc: acpi soc
> > + * @disable_scan_handler: true means remove default scan handle
> > + *			false means use default scan handle
> > + *
> > + * register a new acpi soc into asoc_list and install default scan handle.
> > + */
> 
> IMHO function kernel-docs belong close to the function implementation,
> e.g in this case to acpi_soc.c.
> 
[Ken] so, you suggest a kernel-doc for acpi_soc? i believe acpi_soc is
only a small extension for platform bus support of acpi.

> > +void register_acpi_soc(struct acpi_soc *a_soc, bool disable_scan_handler);
> > +
> > +#endif
> > -- 
> > 1.9.1


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