Re: [PATCH v6 05/12] iommu/exynos: support for device tree

Re: [PATCH v6 05/12] iommu/exynos: support for device tree

[Sylwester Nawrocki]

On 12/26/2012 02:53 AM, Cho KyongHo wrote:
> This commit adds device tree support for System MMU.
> 
> Signed-off-by: KyongHo Cho<pullip.cho-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>

Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org

Please note any patches adding new device tree bindings should be sent
to this mailing list. I have few comments, please see below.

> ---
>   drivers/iommu/Kconfig        |   2 +-
>   drivers/iommu/exynos-iommu.c | 282 ++++++++++++++++++++++++++-----------------
>   2 files changed, 174 insertions(+), 110 deletions(-)
> 
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index e39f9db..64586f1 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -168,7 +168,7 @@ config TEGRA_IOMMU_SMMU
> 
>   config EXYNOS_IOMMU
>   	bool "Exynos IOMMU Support"
> -	depends on ARCH_EXYNOS&&  EXYNOS_DEV_SYSMMU
> +	depends on ARCH_EXYNOS
>   	select IOMMU_API
>   	help
>   	  Support for the IOMMU(System MMU) of Samsung Exynos application
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index 5847508..5b35820 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -1,6 +1,6 @@
> -/* linux/drivers/iommu/exynos_iommu.c
> +/* linux/drivers/iommu/exynos-iommu.c
>    *
> - * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> + * Copyright (c) 2011-2012 Samsung Electronics Co., Ltd.
>    *		http://www.samsung.com
>    *
>    * This program is free software; you can redistribute it and/or modify
> @@ -12,6 +12,7 @@
>   #define DEBUG
>   #endif
> 
> +#include<linux/kernel.h>
>   #include<linux/io.h>
>   #include<linux/interrupt.h>
>   #include<linux/platform_device.h>
> @@ -25,11 +26,10 @@
>   #include<linux/list.h>
>   #include<linux/memblock.h>
>   #include<linux/export.h>
> +#include<linux/of.h>
> +#include<linux/of_platform.h>
> 
>   #include<asm/cacheflush.h>
> -#include<asm/pgtable.h>
> -
> -#include<mach/sysmmu.h>
> 
>   /* We does not consider super section mapping (16MB) */
>   #define SECT_ORDER 20
> @@ -161,14 +161,13 @@ struct sysmmu_drvdata {
>   	struct list_head node; /* entry of exynos_iommu_domain.clients */
>   	struct device *sysmmu;	/* System MMU's device descriptor */
>   	struct device *dev;	/* Owner of system MMU */
> -	char *dbgname;
>   	int nsfrs;
> -	void __iomem **sfrbases;
> -	struct clk *clk[2];
> +	struct clk *clk;
>   	int activations;
>   	spinlock_t lock;
>   	struct iommu_domain *domain;
>   	unsigned long pgtable;
> +	void __iomem *sfrbases[0];
>   };
> 
>   static bool set_sysmmu_active(struct sysmmu_drvdata *data)
> @@ -373,10 +372,8 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
>   	for (i = 0; i<  data->nsfrs; i++)
>   		__raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
> 
> -	if (data->clk[1])
> -		clk_disable(data->clk[1]);
> -	if (data->clk[0])
> -		clk_disable(data->clk[0]);
> +	if (data->clk)
> +		clk_disable(data->clk);
> 
>   	disabled = true;
>   	data->pgtable = 0;
> @@ -385,10 +382,10 @@ finish:
>   	spin_unlock_irqrestore(&data->lock, flags);
> 
>   	if (disabled)
> -		dev_dbg(data->sysmmu, "(%s) Disabled\n", data->dbgname);
> +		dev_dbg(data->sysmmu, "Disabled\n");
>   	else
> -		dev_dbg(data->sysmmu, "(%s) %d times left to be disabled\n",
> -					data->dbgname, data->activations);
> +		dev_dbg(data->sysmmu, "%d times left to be disabled\n",
> +					data->activations);
> 
>   	return disabled;
>   }
> @@ -415,14 +412,12 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
>   			ret = 1;
>   		}
> 
> -		dev_dbg(data->sysmmu, "(%s) Already enabled\n", data->dbgname);
> +		dev_dbg(data->sysmmu, "Already enabled\n");
>   		goto finish;
>   	}
> 
> -	if (data->clk[0])
> -		clk_enable(data->clk[0]);
> -	if (data->clk[1])
> -		clk_enable(data->clk[1]);
> +	if (data->clk)
> +		clk_enable(data->clk);
> 
>   	data->pgtable = pgtable;
> 
> @@ -442,7 +437,7 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
> 
>   	data->domain = domain;
> 
> -	dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
> +	dev_dbg(data->sysmmu, "Enabled\n");
>   finish:
>   	spin_unlock_irqrestore(&data->lock, flags);
> 
> @@ -458,7 +453,7 @@ int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
> 
>   	ret = pm_runtime_get_sync(data->sysmmu);
>   	if (ret<  0) {
> -		dev_dbg(data->sysmmu, "(%s) Failed to enable\n", data->dbgname);
> +		dev_dbg(data->sysmmu, "Failed to enable\n");
>   		return ret;
>   	}
> 
> @@ -466,8 +461,8 @@ int exynos_sysmmu_enable(struct device *dev, unsigned long pgtable)
>   	if (WARN_ON(ret<  0)) {
>   		pm_runtime_put(data->sysmmu);
>   		dev_err(data->sysmmu,
> -			"(%s) Already enabled with page table %#lx\n",
> -			data->dbgname, data->pgtable);
> +			"Already enabled with page table %#lx\n",
> +			data->pgtable);
>   	} else {
>   		data->dev = dev;
>   	}
> @@ -504,8 +499,7 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova)
>   		}
>   	} else {
>   		dev_dbg(data->sysmmu,
> -			"(%s) Disabled. Skipping invalidating TLB.\n",
> -			data->dbgname);
> +			"Disabled. Skipping invalidating TLB.\n");
>   	}
> 
>   	spin_unlock_irqrestore(&data->lock, flags);
> @@ -528,138 +522,208 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
>   		}
>   	} else {
>   		dev_dbg(data->sysmmu,
> -			"(%s) Disabled. Skipping invalidating TLB.\n",
> -			data->dbgname);
> +			"Disabled. Skipping invalidating TLB.\n");
>   	}
> 
>   	spin_unlock_irqrestore(&data->lock, flags);
>   }
> 
> -static int exynos_sysmmu_probe(struct platform_device *pdev)
> +static int __init __sysmmu_init_clock(struct device *sysmmu,
> +					struct sysmmu_drvdata *drvdata,
> +					struct device *master)
>   {
> -	int i, ret;
> -	struct device *dev;
> -	struct sysmmu_drvdata *data;
> +	char *conid;
> +	struct clk *parent_clk;
> +	int ret;
> 
> -	dev =&pdev->dev;
> +	drvdata->clk = clk_get(sysmmu, "sysmmu");
> +	if (IS_ERR(drvdata->clk)) {
> +		dev_dbg(sysmmu, "No gating clock found.\n");
> +		drvdata->clk = NULL;
> +		return 0;
> +	}
> 
> -	data = kzalloc(sizeof(*data), GFP_KERNEL);
> -	if (!data) {
> -		dev_dbg(dev, "Not enough memory\n");
> -		ret = -ENOMEM;
> -		goto err_alloc;
> +	if (!master)
> +		return 0;
> +
> +	conid = dev_get_platdata(sysmmu);
> +	if (!conid) {
> +		dev_dbg(sysmmu, "No parent clock specified.\n");
> +		return 0;
>   	}
> 
> -	ret = dev_set_drvdata(dev, data);
> +	parent_clk = clk_get(master, conid);
> +	if (IS_ERR(parent_clk)) {
> +		parent_clk = clk_get(NULL, conid);
> +		if (IS_ERR(parent_clk)) {
> +			clk_put(drvdata->clk);
> +			dev_err(sysmmu, "No parent clock '%s,%s' found\n",
> +				dev_name(master), conid);
> +			return PTR_ERR(parent_clk);
> +		}
> +	}
> +
> +	ret = clk_set_parent(drvdata->clk, parent_clk);
>   	if (ret) {
> -		dev_dbg(dev, "Unabled to initialize driver data\n");
> -		goto err_init;
> +		clk_put(drvdata->clk);
> +		dev_err(sysmmu, "Failed to set parent clock '%s,%s'\n",
> +				dev_name(master), conid);
>   	}
> 
> -	data->nsfrs = pdev->num_resources / 2;
> -	data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
> -								GFP_KERNEL);
> -	if (data->sfrbases == NULL) {
> -		dev_dbg(dev, "Not enough memory\n");
> -		ret = -ENOMEM;
> -		goto err_init;
> +	clk_put(parent_clk);
> +
> +	return ret;
> +}
> +
> +static int __init __sysmmu_setup(struct device *sysmmu,
> +				struct sysmmu_drvdata *drvdata)
> +{
> +	struct device_node *master_node;
> +	const char *compat;
> +	struct platform_device *pmaster = NULL;
> +	u32 master_inst_no = -1;
> +	int ret;
> +
> +	master_node = of_parse_phandle(sysmmu->of_node, "mmu-master", 0);
> +	if (!master_node&&  !of_property_read_string(
> +			sysmmu->of_node, "mmu-master-compat",&compat)) {
> +		of_property_read_u32_array(sysmmu->of_node,
> +					"mmu-master-no",&master_inst_no, 1);
> +		for_each_compatible_node(master_node, NULL, compat) {
> +			pmaster = of_find_device_by_node(master_node);
> +			if (pmaster&&  (pmaster->id == master_inst_no))
> +				break;
> +			of_dev_put(pmaster);
> +			pmaster = NULL;
> +		}
> +	} else if (master_node) {
> +		pmaster = of_find_device_by_node(master_node);
> +	}
> +
> +	if (!pmaster) {
> +		dev_dbg(sysmmu, "No master device is specified.\n");
> +		return __sysmmu_init_clock(sysmmu, drvdata, NULL);
> +	}
> +
> +	pmaster->dev.archdata.iommu = sysmmu;
> +
> +	ret = __sysmmu_init_clock(sysmmu, drvdata,&pmaster->dev);
> +	if (ret)
> +		dev_err(sysmmu, "Failed to initialize gating clocks\n");
> +
> +	of_dev_put(pmaster);
> +
> +	return ret;
> +}
> +
> +static int __init exynos_sysmmu_probe(struct platform_device *pdev)
> +{
> +	int i, ret;
> +	struct device *dev =&pdev->dev;
> +	struct sysmmu_drvdata *data;
> +
> +	if (pdev->num_resources == 0) {
> +		dev_err(dev, "No System MMU resource defined\n");
> +		return -ENODEV;
> +	}
> +
> +	data = devm_kzalloc(dev,
> +			sizeof(*data)
> +			+ sizeof(*data->sfrbases) * (pdev->num_resources / 2),
> +			GFP_KERNEL);
> +	if (!data) {
> +		dev_err(dev, "Not enough memory\n");
> +		return -ENOMEM;
>   	}
> 
> +	data->nsfrs = pdev->num_resources / 2;
> +
>   	for (i = 0; i<  data->nsfrs; i++) {
>   		struct resource *res;
>   		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
>   		if (!res) {
> -			dev_dbg(dev, "Unable to find IOMEM region\n");
> -			ret = -ENOENT;
> -			goto err_res;
> +			dev_err(dev, "Unable to find IOMEM region\n");
> +			return -ENOENT;
>   		}
> 
> -		data->sfrbases[i] = ioremap(res->start, resource_size(res));
> +		data->sfrbases[i] = devm_request_and_ioremap(dev, res);
>   		if (!data->sfrbases[i]) {
> -			dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
> +			dev_err(dev, "Unable to map IOMEM @ PA:%#x\n",
>   							res->start);
> -			ret = -ENOENT;
> -			goto err_res;
> +			return -EBUSY;
>   		}
>   	}
> 
>   	for (i = 0; i<  data->nsfrs; i++) {
>   		ret = platform_get_irq(pdev, i);
>   		if (ret<= 0) {
> -			dev_dbg(dev, "Unable to find IRQ resource\n");
> -			goto err_irq;
> +			dev_err(dev, "Unable to find IRQ resource\n");
> +			return ret;
>   		}
> 
> -		ret = request_irq(ret, exynos_sysmmu_irq, 0,
> +		ret = devm_request_irq(dev, ret, exynos_sysmmu_irq, 0,
>   					dev_name(dev), data);
>   		if (ret) {
> -			dev_dbg(dev, "Unabled to register interrupt handler\n");
> -			goto err_irq;
> +			dev_err(dev, "Unabled to register interrupt handler\n");
> +			return ret;
>   		}
>   	}
> 
> -	if (dev_get_platdata(dev)) {
> -		char *deli, *beg;
> -		struct sysmmu_platform_data *platdata = dev_get_platdata(dev);
> -
> -		beg = platdata->clockname;
> -
> -		for (deli = beg; (*deli != '\0')&&  (*deli != ','); deli++)
> -			/* NOTHING */;
> -
> -		if (*deli == '\0')
> -			deli = NULL;
> -		else
> -			*deli = '\0';
> -
> -		data->clk[0] = clk_get(dev, beg);
> -		if (IS_ERR(data->clk[0])) {
> -			data->clk[0] = NULL;
> -			dev_dbg(dev, "No clock descriptor registered\n");
> -		}
> -
> -		if (data->clk[0]&&  deli) {
> -			*deli = ',';
> -			data->clk[1] = clk_get(dev, deli + 1);
> -			if (IS_ERR(data->clk[1]))
> -				data->clk[1] = NULL;
> -		}
> -
> -		data->dbgname = platdata->dbgname;
> -	}
> 
> -	data->sysmmu = dev;
> -	spin_lock_init(&data->lock);
> -	INIT_LIST_HEAD(&data->node);
> +	ret = __sysmmu_setup(dev, data);
> +	if (!ret) {
> +		data->sysmmu = dev;
> +		spin_lock_init(&data->lock);
> +		INIT_LIST_HEAD(&data->node);
> 
> -	if (dev->parent)
>   		pm_runtime_enable(dev);
> 
> -	dev_dbg(dev, "(%s) Initialized\n", data->dbgname);
> -	return 0;
> -err_irq:
> -	while (i-->  0) {
> -		int irq;
> +		platform_set_drvdata(pdev, data);
> 
> -		irq = platform_get_irq(pdev, i);
> -		free_irq(irq, data);
> +		dev_dbg(dev, "Initialized\n");
>   	}
> -err_res:
> -	while (data->nsfrs-->  0)
> -		iounmap(data->sfrbases[data->nsfrs]);
> -	kfree(data->sfrbases);
> -err_init:
> -	kfree(data);
> -err_alloc:
> -	dev_err(dev, "Failed to initialize\n");
> +
>   	return ret;
>   }
> 
> -static struct platform_driver exynos_sysmmu_driver = {
> +/*
> + * Descriptions of Device Tree node for System MMU
> + *
> + * A System MMU should be described by a single tree node.
> + *
> + * A System MMU node should have the following properties:
> + * - reg: tuples of the base address and the size of the IO region of System MMU
> + * - compatible: it must be "samsung,exynos-sysmmu".

I think this compatible property is too generic. It should include
specific SoC
name in it, e.g. samsung,exynos4210-sysmmu. Please refer to this thread
http://www.spinics.net/lists/linux-omap/msg83512.html, which discusses
similar issue.

> + * - interrupt-parent = specify if the interrupt of System MMU is generated by
> + *   interrupt combiner or interrupt controller.
> + * - interrupts: tuples of interrupt numbers. a tuple has 2 elements if
> + *   @interrupt-parent is '<&combiner>', 3 elements otherwise.

It's probably enough to say that format of the interrupts property is
dependant on
the interrupt controller used.

> + *
> + * 'mmuname', 'reg' and 'interrupts' properties can be an array if the System
> + * MMU driver controls several number of System MMUs at the same time. Note that
> + * the number of elements in those three properties must be the same.

It might be useful to provide some example here.

> + * The following properties are optional:
> + * - mmuname: name of the System MMU for debugging purpose

Not sure if it is something that is supposed to be included in FDT. You
could
probably derive it from the 'compatible' property, if it is really
needed. The device
tree bindings should not be treated as direct replacement for platform data
structures.

> + * - mmu-master: reference to the node of the master device.
> + * - mmu-master-compat: 'compatible' proberty of the node of the master device
> + *    of System MMU. This is ignored if @mmu-master is currectly specified.
> + * - mmu-master-no: instance number of the master device of System MMU. This is
> + *    ignored if @mmu-master is correctly specified. This is '0' by default.

Maybe device node aliases would be better alternative here ? But what
would be
a use case where you can't set 'mmu-master' and 'mmu-master-no' is needed ?

> + */
> +#ifdef CONFIG_OF
> +static struct of_device_id sysmmu_of_match[] __initconst = {
> +	{ .compatible = "samsung,exynos-sysmmu", },
> +	{ },
> +};
> +#endif
> +
> +static struct platform_driver exynos_sysmmu_driver __refdata = {
>   	.probe		= exynos_sysmmu_probe,
>   	.driver		= {
>   		.owner		= THIS_MODULE,
>   		.name		= "exynos-sysmmu",
> +		.of_match_table = of_match_ptr(sysmmu_of_match),
>   	}
>   };

Re: [PATCH v6 05/12] iommu/exynos: support for device tree

[KyongHo Cho]

[-- Attachment #1.1: Type: text/plain, Size: 18332 bytes --]

On Tuesday, January 1, 2013, Sylwester Nawrocki <
sylvester.nawrocki-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On 12/26/2012 02:53 AM, Cho KyongHo wrote:
>> This commit adds device tree support for System MMU.
>>
>> Signed-off-by: KyongHo Cho<pullip.cho-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>
> Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org
>
> Please note any patches adding new device tree bindings should be sent
> to this mailing list. I have few comments, please see below.
>
Ok. I got it. thank you.
>> ---
>>   drivers/iommu/Kconfig        |   2 +-
>>   drivers/iommu/exynos-iommu.c | 282
++++++++++++++++++++++++++-----------------
>>   2 files changed, 174 insertions(+), 110 deletions(-)
>>
>> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
>> index e39f9db..64586f1 100644
>> --- a/drivers/iommu/Kconfig
>> +++ b/drivers/iommu/Kconfig
>> @@ -168,7 +168,7 @@ config TEGRA_IOMMU_SMMU
>>
>>   config EXYNOS_IOMMU
>>       bool "Exynos IOMMU Support"
>> -     depends on ARCH_EXYNOS&&  EXYNOS_DEV_SYSMMU
>> +     depends on ARCH_EXYNOS
>>       select IOMMU_API
>>       help
>>         Support for the IOMMU(System MMU) of Samsung Exynos application
>> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
>> index 5847508..5b35820 100644
>> --- a/drivers/iommu/exynos-iommu.c
>> +++ b/drivers/iommu/exynos-iommu.c
>> @@ -1,6 +1,6 @@
>> -/* linux/drivers/iommu/exynos_iommu.c
>> +/* linux/drivers/iommu/exynos-iommu.c
>>    *
>> - * Copyright (c) 2011 Samsung Electronics Co., Ltd.
>> + * Copyright (c) 2011-2012 Samsung Electronics Co., Ltd.
>>    *          http://www.samsung.com
>>    *
>>    * This program is free software; you can redistribute it and/or modify
>> @@ -12,6 +12,7 @@
>>   #define DEBUG
>>   #endif
>>
>> +#include<linux/kernel.h>
>>   #include<linux/io.h>
>>   #include<linux/interrupt.h>
>>   #include<linux/platform_device.h>
>> @@ -25,11 +26,10 @@
>>   #include<linux/list.h>
>>   #include<linux/memblock.h>
>>   #include<linux/export.h>
>> +#include<linux/of.h>
>> +#include<linux/of_platform.h>
>>
>>   #include<asm/cacheflush.h>
>> -#include<asm/pgtable.h>
>> -
>> -#include<mach/sysmmu.h>
>>
>>   /* We does not consider super section mapping (16MB) */
>>   #define SECT_ORDER 20
>> @@ -161,14 +161,13 @@ struct sysmmu_drvdata {
>>       struct list_head node; /* entry of exynos_iommu_domain.clients */
>>       struct device *sysmmu;  /* System MMU's device descriptor */
>>       struct device *dev;     /* Owner of system MMU */
>> -     char *dbgname;
>>       int nsfrs;
>> -     void __iomem **sfrbases;
>> -     struct clk *clk[2];
>> +     struct clk *clk;
>>       int activations;
>>       spinlock_t lock;
>>       struct iommu_domain *domain;
>>       unsigned long pgtable;
>> +     void __iomem *sfrbases[0];
>>   };
>>
>>   static bool set_sysmmu_active(struct sysmmu_drvdata *data)
>> @@ -373,10 +372,8 @@ static bool __exynos_sysmmu_disable(struct
sysmmu_drvdata *data)
>>       for (i = 0; i<  data->nsfrs; i++)
>>               __raw_writel(CTRL_DISABLE, data->sfrbases[i] +
REG_MMU_CTRL);
>>
>> -     if (data->clk[1])
>> -             clk_disable(data->clk[1]);
>> -     if (data->clk[0])
>> -             clk_disable(data->clk[0]);
>> +     if (data->clk)
>> +             clk_disable(data->clk);
>>
>>       disabled = true;
>>       data->pgtable = 0;
>> @@ -385,10 +382,10 @@ finish:
>>       spin_unlock_irqrestore(&data->lock, flags);
>>
>>       if (disabled)
>> -             dev_dbg(data->sysmmu, "(%s) Disabled\n", data->dbgname);
>> +             dev_dbg(data->sysmmu, "Disabled\n");
>>       else
>> -             dev_dbg(data->sysmmu, "(%s) %d times left to be
disabled\n",
>> -                                     data->dbgname, data->activations);
>> +             dev_dbg(data->sysmmu, "%d times left to be disabled\n",
>> +                                     data->activations);
>>
>>       return disabled;
>>   }
>> @@ -415,14 +412,12 @@ static int __exynos_sysmmu_enable(struct
sysmmu_drvdata *data,
>>                       ret = 1;
>>               }
>>
>> -             dev_dbg(data->sysmmu, "(%s) Already enabled\n",
data->dbgname);
>> +             dev_dbg(data->sysmmu, "Already enabled\n");
>>               goto finish;
>>       }
>>
>> -     if (data->clk[0])
>> -             clk_enable(data->clk[0]);
>> -     if (data->clk[1])
>> -             clk_enable(data->clk[1]);
>> +     if (data->clk)
>> +             clk_enable(data->clk);
>>
>>       data->pgtable = pgtable;
>>
>> @@ -442,7 +437,7 @@ static int __exynos_sysmmu_enable(struct
sysmmu_drvdata *data,
>>
>>       data->domain = domain;
>>
>> -     dev_dbg(data->sysmmu, "(%s) Enabled\n", data->dbgname);
>> +     dev_dbg(data->sysmmu, "Enabled\n");
>>   finish:
>>       spin_unlock_irqrestore(&data->lock, flags);
>>
>> @@ -458,7 +453,7 @@ int exynos_sysmmu_enable(struct device *dev,
unsigned long pgtable)
>>
>>       ret = pm_runtime_get_sync(data->sysmmu);
>>       if (ret<  0) {
>> -             dev_dbg(data->sysmmu, "(%s) Failed to enable\n",
data->dbgname);
>> +             dev_dbg(data->sysmmu, "Failed to enable\n");
>>               return ret;
>>       }
>>
>> @@ -466,8 +461,8 @@ int exynos_sysmmu_enable(struct device *dev,
unsigned long pgtable)
>>       if (WARN_ON(ret<  0)) {
>>               pm_runtime_put(data->sysmmu);
>>               dev_err(data->sysmmu,
>> -                     "(%s) Already enabled with page table %#lx\n",
>> -                     data->dbgname, data->pgtable);
>> +                     "Already enabled with page table %#lx\n",
>> +                     data->pgtable);
>>       } else {
>>               data->dev = dev;
>>       }
>> @@ -504,8 +499,7 @@ static void sysmmu_tlb_invalidate_entry(struct
device *dev, unsigned long iova)
>>               }
>>       } else {
>>               dev_dbg(data->sysmmu,
>> -                     "(%s) Disabled. Skipping invalidating TLB.\n",
>> -                     data->dbgname);
>> +                     "Disabled. Skipping invalidating TLB.\n");
>>       }
>>
>>       spin_unlock_irqrestore(&data->lock, flags);
>> @@ -528,138 +522,208 @@ void exynos_sysmmu_tlb_invalidate(struct device
*dev)
>>               }
>>       } else {
>>               dev_dbg(data->sysmmu,
>> -                     "(%s) Disabled. Skipping invalidating TLB.\n",
>> -                     data->dbgname);
>> +                     "Disabled. Skipping invalidating TLB.\n");
>>       }
>>
>>       spin_unlock_irqrestore(&data->lock, flags);
>>   }
>>
>> -static int exynos_sysmmu_probe(struct platform_device *pdev)
>> +static int __init __sysmmu_init_clock(struct device *sysmmu,
>> +                                     struct sysmmu_drvdata *drvdata,
>> +                                     struct device *master)
>>   {
>> -     int i, ret;
>> -     struct device *dev;
>> -     struct sysmmu_drvdata *data;
>> +     char *conid;
>> +     struct clk *parent_clk;
>> +     int ret;
>>
>> -     dev =&pdev->dev;
>> +     drvdata->clk = clk_get(sysmmu, "sysmmu");
>> +     if (IS_ERR(drvdata->clk)) {
>> +             dev_dbg(sysmmu, "No gating clock found.\n");
>> +             drvdata->clk = NULL;
>> +             return 0;
>> +     }
>>
>> -     data = kzalloc(sizeof(*data), GFP_KERNEL);
>> -     if (!data) {
>> -             dev_dbg(dev, "Not enough memory\n");
>> -             ret = -ENOMEM;
>> -             goto err_alloc;
>> +     if (!master)
>> +             return 0;
>> +
>> +     conid = dev_get_platdata(sysmmu);
>> +     if (!conid) {
>> +             dev_dbg(sysmmu, "No parent clock specified.\n");
>> +             return 0;
>>       }
>>
>> -     ret = dev_set_drvdata(dev, data);
>> +     parent_clk = clk_get(master, conid);
>> +     if (IS_ERR(parent_clk)) {
>> +             parent_clk = clk_get(NULL, conid);
>> +             if (IS_ERR(parent_clk)) {
>> +                     clk_put(drvdata->clk);
>> +                     dev_err(sysmmu, "No parent clock '%s,%s' found\n",
>> +                             dev_name(master), conid);
>> +                     return PTR_ERR(parent_clk);
>> +             }
>> +     }
>> +
>> +     ret = clk_set_parent(drvdata->clk, parent_clk);
>>       if (ret) {
>> -             dev_dbg(dev, "Unabled to initialize driver data\n");
>> -             goto err_init;
>> +             clk_put(drvdata->clk);
>> +             dev_err(sysmmu, "Failed to set parent clock '%s,%s'\n",
>> +                             dev_name(master), conid);
>>       }
>>
>> -     data->nsfrs = pdev->num_resources / 2;
>> -     data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
>> -
GFP_KERNEL);
>> -     if (data->sfrbases == NULL) {
>> -             dev_dbg(dev, "Not enough memory\n");
>> -             ret = -ENOMEM;
>> -             goto err_init;
>> +     clk_put(parent_clk);
>> +
>> +     return ret;
>> +}
>> +
>> +static int __init __sysmmu_setup(struct device *sysmmu,
>> +                             struct sysmmu_drvdata *drvdata)
>> +{
>> +     struct device_node *master_node;
>> +     const char *compat;
>> +     struct platform_device *pmaster = NULL;
>> +     u32 master_inst_no = -1;
>> +     int ret;
>> +
>> +     master_node = of_parse_phandle(sysmmu->of_node, "mmu-master", 0);
>> +     if (!master_node&&  !of_property_read_string(
>> +                     sysmmu->of_node, "mmu-master-compat",&compat)) {
>> +             of_property_read_u32_array(sysmmu->of_node,
>> +                                     "mmu-master-no",&master_inst_no,
1);
>> +             for_each_compatible_node(master_node, NULL, compat) {
>> +                     pmaster = of_find_device_by_node(master_node);
>> +                     if (pmaster&&  (pmaster->id == master_inst_no))
>> +                             break;
>> +                     of_dev_put(pmaster);
>> +                     pmaster = NULL;
>> +             }
>> +     } else if (master_node) {
>> +             pmaster = of_find_device_by_node(master_node);
>> +     }
>> +
>> +     if (!pmaster) {
>> +             dev_dbg(sysmmu, "No master device is specified.\n");
>> +             return __sysmmu_init_clock(sysmmu, drvdata, NULL);
>> +     }
>> +
>> +     pmaster->dev.archdata.iommu = sysmmu;
>> +
>> +     ret = __sysmmu_init_clock(sysmmu, drvdata,&pmaster->dev);
>> +     if (ret)
>> +             dev_err(sysmmu, "Failed to initialize gating clocks\n");
>> +
>> +     of_dev_put(pmaster);
>> +
>> +     return ret;
>> +}
>> +
>> +static int __init exynos_sysmmu_probe(struct platform_device *pdev)
>> +{
>> +     int i, ret;
>> +     struct device *dev =&pdev->dev;
>> +     struct sysmmu_drvdata *data;
>> +
>> +     if (pdev->num_resources == 0) {
>> +             dev_err(dev, "No System MMU resource defined\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     data = devm_kzalloc(dev,
>> +                     sizeof(*data)
>> +                     + sizeof(*data->sfrbases) * (pdev->num_resources /
2),
>> +                     GFP_KERNEL);
>> +     if (!data) {
>> +             dev_err(dev, "Not enough memory\n");
>> +             return -ENOMEM;
>>       }
>>
>> +     data->nsfrs = pdev->num_resources / 2;
>> +
>>       for (i = 0; i<  data->nsfrs; i++) {
>>               struct resource *res;
>>               res = platform_get_resource(pdev, IORESOURCE_MEM, i);
>>               if (!res) {
>> -                     dev_dbg(dev, "Unable to find IOMEM region\n");
>> -                     ret = -ENOENT;
>> -                     goto err_res;
>> +                     dev_err(dev, "Unable to find IOMEM region\n");
>> +                     return -ENOENT;
>>               }
>>
>> -             data->sfrbases[i] = ioremap(res->start,
resource_size(res));
>> +             data->sfrbases[i] = devm_request_and_ioremap(dev, res);
>>               if (!data->sfrbases[i]) {
>> -                     dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
>> +                     dev_err(dev, "Unable to map IOMEM @ PA:%#x\n",
>>                                                       res->start);
>> -                     ret = -ENOENT;
>> -                     goto err_res;
>> +                     return -EBUSY;
>>               }
>>       }
>>
>>       for (i = 0; i<  data->nsfrs; i++) {
>>               ret = platform_get_irq(pdev, i);
>>               if (ret<= 0) {
>> -                     dev_dbg(dev, "Unable to find IRQ resource\n");
>> -                     goto err_irq;
>> +                     dev_err(dev, "Unable to find IRQ resource\n");
>> +                     return ret;
>>               }
>>
>> -             ret = request_irq(ret, exynos_sysmmu_irq, 0,
>> +             ret = devm_request_irq(dev, ret, exynos_sysmmu_irq, 0,
>>                                       dev_name(dev), data);
>>               if (ret) {
>> -                     dev_dbg(dev, "Unabled to register interrupt
handler\n");
>> -                     goto err_irq;
>> +                     dev_err(dev, "Unabled to register interrupt
handler\n");
>> +                     return ret;
>>               }
>>       }
>>
>> -     if (dev_get_platdata(dev)) {
>> -             char *deli, *beg;
>> -             struct sysmmu_platform_data *platdata =
dev_get_platdata(dev);
>> -
>> -             beg = platdata->clockname;
>> -
>> -             for (deli = beg; (*deli != '\0')&&  (*deli != ','); deli++)
>> -                     /* NOTHING */;
>> -
>> -             if (*deli == '\0')
>> -                     deli = NULL;
>> -             else
>> -                     *deli = '\0';
>> -
>> -             data->clk[0] = clk_get(dev, beg);
>> -             if (IS_ERR(data->clk[0])) {
>> -                     data->clk[0] = NULL;
>> -                     dev_dbg(dev, "No clock descriptor registered\n");
>> -             }
>> -
>> -             if (data->clk[0]&&  deli) {
>> -                     *deli = ',';
>> -                     data->clk[1] = clk_get(dev, deli + 1);
>> -                     if (IS_ERR(data->clk[1]))
>> -                             data->clk[1] = NULL;
>> -             }
>> -
>> -             data->dbgname = platdata->dbgname;
>> -     }
>>
>> -     data->sysmmu = dev;
>> -     spin_lock_init(&data->lock);
>> -     INIT_LIST_HEAD(&data->node);
>> +     ret = __sysmmu_setup(dev, data);
>> +     if (!ret) {
>> +             data->sysmmu = dev;
>> +             spin_lock_init(&data->lock);
>> +             INIT_LIST_HEAD(&data->node);
>>
>> -     if (dev->parent)
>>               pm_runtime_enable(dev);
>>
>> -     dev_dbg(dev, "(%s) Initialized\n", data->dbgname);
>> -     return 0;
>> -err_irq:
>> -     while (i-->  0) {
>> -             int irq;
>> +             platform_set_drvdata(pdev, data);
>>
>> -             irq = platform_get_irq(pdev, i);
>> -             free_irq(irq, data);
>> +             dev_dbg(dev, "Initialized\n");
>>       }
>> -err_res:
>> -     while (data->nsfrs-->  0)
>> -             iounmap(data->sfrbases[data->nsfrs]);
>> -     kfree(data->sfrbases);
>> -err_init:
>> -     kfree(data);
>> -err_alloc:
>> -     dev_err(dev, "Failed to initialize\n");
>> +
>>       return ret;
>>   }
>>
>> -static struct platform_driver exynos_sysmmu_driver = {
>> +/*
>> + * Descriptions of Device Tree node for System MMU
>> + *
>> + * A System MMU should be described by a single tree node.
>> + *
>> + * A System MMU node should have the following properties:
>> + * - reg: tuples of the base address and the size of the IO region of
System MMU
>> + * - compatible: it must be "samsung,exynos-sysmmu".
>
> I think this compatible property is too generic. It should include
> specific SoC
> name in it, e.g. samsung,exynos4210-sysmmu. Please refer to this thread
> http://www.spinics.net/lists/linux-omap/msg83512.html, which discusses
> similar issue.

Ok, I got the point. BTW , I think this will cause adding a compatibility
property whenever a SoC is released even though it has completely
sameSystem MMU. Is it inevitable?

>> + * - interrupt-parent = specify if the interrupt of System MMU is
generated by
>> + *   interrupt combiner or interrupt controller.
>> + * - interrupts: tuples of interrupt numbers. a tuple has 2 elements if
>> + *   @interrupt-parent is '<&combiner>', 3 elements otherwise.
>
> It's probably enough to say that format of the interrupts property is
> dependant on
> the interrupt controller used.

I agree that :)

>> + *
>> + * 'mmuname', 'reg' and 'interrupts' properties can be an array if the
System
>> + * MMU driver controls several number of System MMUs at the same time.
Note that
>> + * the number of elements in those three properties must be the same.
>
> It might be useful to provide some example here.

examples are there in Documentations directory.

>> + * The following properties are optional:
>> + * - mmuname: name of the System MMU for debugging purpose
>
> Not sure if it is something that is supposed to be included in FDT. You
> could
> probably derive it from the 'compatible' property, if it is really
> needed. The device
> tree bindings should not be treated as direct replacement for platform
data
> structures.

actually it is just for debugging purpose.
I understand that it should not be there.
Thank you.

>> + * - mmu-master: reference to the node of the master device.
>> + * - mmu-master-compat: 'compatible' proberty of the node of the master
device
>> + *    of System MMU. This is ignored if @mmu-master is currectly
specified.
>> + * - mmu-master-no: instance number of the master device of System MMU.
This is
>> + *    ignored if @mmu-master is correctly specified. This is '0' by
default.
>
> Maybe device node aliases would be better alternative here ? But what
> would be
> a use case where you can't set 'mmu-master' and 'mmu-master-no' is needed
?

It is for platform devices that are not specified in FDT.
Don't we need consider that?

>> + */
>> +#ifdef CONFIG_OF
>> +static struct of_device_id sysmmu_of_match[] __initconst = {
>> +     { .compatible = "samsung,exynos-sysmmu", },
>> +     { },
>> +};
>> +#endif
>> +
>> +static struct platform_driver exynos_sysmmu_driver __refdata = {
>>       .probe          = exynos_sysmmu_probe,
>>       .driver         = {
>>               .owner          = THIS_MODULE,
>>               .name           = "exynos-sysmmu",
>> +             .of_match_table = of_match_ptr(sysmmu_of_match),
>>       }
>>   };

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Re: [PATCH v6 05/12] iommu/exynos: support for device tree

[Sylwester Nawrocki]

On 01/02/2013 06:53 AM, KyongHo Cho wrote:
>> > +/*
>> > + * Descriptions of Device Tree node for System MMU
>> > + *
>> > + * A System MMU should be described by a single tree node.
>> > + *
>> > + * A System MMU node should have the following properties:
>> > + * - reg: tuples of the base address and the size of the IO region
> of System MMU
>> > + * - compatible: it must be "samsung,exynos-sysmmu".
>>
>>  I think this compatible property is too generic. It should include
>>  specific SoC
>>  name in it, e.g. samsung,exynos4210-sysmmu. Please refer to this thread
>>  http://www.spinics.net/lists/linux-omap/msg83512.html, which discusses
>>  similar issue.
>
> Ok, I got the point. BTW , I think this will cause adding a
> compatibility property whenever a SoC is released even though it has
> completely sameSystem MMU. Is it inevitable?

No, there is no need for separate 'compatible' property for each SoC.
If the iommu is same across several SoCs same 'compatible' string should be
used for it. Please refer to the below table.

  SoC       | sysmmu type |    compatible
-------------------------------------------------------------
exynos4210 |  A          | samsung,exynos4210-sysmmu
exynos4212 |  A          | samsung,exynos4210-sysmmu
exynos4412 |  B          | samsung,exynos4412-sysmmu
exynos5250 |  C          | samsung,exynos5250-sysmmu

In fact, the sysmmu device compatible property could contain more than one
string, e.g.

   compatible = "samsung,exynos4412-sysmmu", "samsung,exynos4210-sysmmu";

if type A is subset of type B in terms of functionality and the register
maps are compatible.

It might be useful to put in the documentation which compatible applies
to which SoC. Then the driver can distinguish between different versions
of the hardware by looking at the 'compatible' property.

In patch "[PATCH v6 10/12] iommu/exynos: pass version information from DT"
you are doing something that looks strange to me. Couldn't you use 
compatible
property to derive the SYSMMU major/minor version information ? Or do these
numbers differ even within single SoC type ?

>> > + * - interrupt-parent = specify if the interrupt of System MMU is
> generated by
>> > + *   interrupt combiner or interrupt controller.
>> > + * - interrupts: tuples of interrupt numbers. a tuple has 2 elements if
>> > + *   @interrupt-parent is '<&combiner>', 3 elements otherwise.
>>
>>  It's probably enough to say that format of the interrupts property is
>>  dependant on
>>  the interrupt controller used.
>
> I agree that :)
>
>> > + *
>> > + * 'mmuname', 'reg' and 'interrupts' properties can be an array if
> the System
>> > + * MMU driver controls several number of System MMUs at the same
> time. Note that
>> > + * the number of elements in those three properties must be the same.
>>
>>  It might be useful to provide some example here.
>
> examples are there in Documentations directory.

Oops, sorry. I missed these are just comments in the code. AFAIU, there is
no need to keep 2 copies of the binding's description. I would put it only
under the Documentation directory.

>> > + * The following properties are optional:
>> > + * - mmuname: name of the System MMU for debugging purpose
>>
>>  Not sure if it is something that is supposed to be included in FDT. You
>>  could
>>  probably derive it from the 'compatible' property, if it is really
>>  needed. The device
>>  tree bindings should not be treated as direct replacement for platform
>>  data structures.
>
> actually it is just for debugging purpose.
> I understand that it should not be there.
> Thank you.
>
>> > + * - mmu-master: reference to the node of the master device.
>> > + * - mmu-master-compat: 'compatible' proberty of the node of the
> master device
>> > + *    of System MMU. This is ignored if @mmu-master is currectly
> specified.
>> > + * - mmu-master-no: instance number of the master device of System
> MMU. This is
>> > + *    ignored if @mmu-master is correctly specified. This is '0' by
> default.
>>
>>  Maybe device node aliases would be better alternative here ? But what
>>  would be
>>  a use case where you can't set 'mmu-master' and 'mmu-master-no' is
> needed ?
>
> It is for platform devices that are not specified in FDT.
> Don't we need consider that?

I don't think there is a need for that. But I might be missing something.
In any case it's probably better to use aliases, e.g. like it's done with
the exynos5 gscaler device.

Re: [PATCH v6 05/12] iommu/exynos: support for device tree

[Joerg Roedel]

Cho,

On Wed, Jan 02, 2013 at 02:53:49PM +0900, KyongHo Cho wrote:
> On Tuesday, January 1, 2013, Sylwester Nawrocki <sylvester.nawrocki@gmail.com>

> > Cc: devicetree-discuss@lists.ozlabs.org

Since patch 7 of this set is already merged, do you mind to re-post the
rest of this patch-set with the latest comments addressed? I can have a
look at it again then and consider it for 3.9.

Thanks,

	Joerg

Re: [PATCH v6 05/12] iommu/exynos: support for device tree

[KyongHo Cho]

On Fri, Feb 1, 2013 at 10:51 PM, Joerg Roedel <joro@8bytes.org> wrote:
> Cho,
>
> On Wed, Jan 02, 2013 at 02:53:49PM +0900, KyongHo Cho wrote:
>> On Tuesday, January 1, 2013, Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
>
>> > Cc: devicetree-discuss@lists.ozlabs.org
>
> Since patch 7 of this set is already merged, do you mind to re-post the
> rest of this patch-set with the latest comments addressed? I can have a
> look at it again then and consider it for 3.9.
>
Thank you for your considerations.

I also think that I need to post the patch set again with some fixes that are
addressed in the comments.

Due to the heavy workload in my business I have hardly had a chance to
handle this patch-set.
As soon as the business lets me handle other pending issues, I will
work on this patchset.
I think I can start to it in the next 2 weeks.

Thank you.

KyongHo.

RE: [PATCH v6 05/12] iommu/exynos: support for device tree

[Kukjin Kim]

KyongHo Cho wrote:
> 
> On Fri, Feb 1, 2013 at 10:51 PM, Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org> wrote:
> > Cho,
> >
> > On Wed, Jan 02, 2013 at 02:53:49PM +0900, KyongHo Cho wrote:
> >> On Tuesday, January 1, 2013, Sylwester Nawrocki
> <sylvester.nawrocki-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> >
> >> > Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org
> >
> > Since patch 7 of this set is already merged, do you mind to re-post the
> > rest of this patch-set with the latest comments addressed? I can have a
> > look at it again then and consider it for 3.9.
> >
> Thank you for your considerations.
> 
> I also think that I need to post the patch set again with some fixes that
are
> addressed in the comments.
> 
> Due to the heavy workload in my business I have hardly had a chance to
> handle this patch-set.
> As soon as the business lets me handle other pending issues, I will
> work on this patchset.
> I think I can start to it in the next 2 weeks.
> 
OK, I see.

Joerg, please hold this on until KyongHo's re-work, probably 3.10?

Thanks.

- Kukjin