[PATCH v6 05/12] iommu/exynos: support for device tree
KyongHo Cho
pullip.cho at samsung.com
Wed Jan 2 00:53:49 EST 2013
On Tuesday, January 1, 2013, Sylwester Nawrocki <
sylvester.nawrocki at gmail.com> 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 at samsung.com>
>
> Cc: devicetree-discuss at lists.ozlabs.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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