Message-ID: <569CBA50.7000400@gmail.com>
Date:	Mon, 18 Jan 2016 11:11:28 +0100
From:	Matthias Brugger <matthias.bgg@...il.com>
To:	Yong Wu <yong.wu@...iatek.com>, Joerg Roedel <joro@...tes.org>,
	Thierry Reding <treding@...dia.com>,
	Mark Rutland <mark.rutland@....com>
Cc:	Robin Murphy <robin.murphy@....com>,
	Will Deacon <will.deacon@....com>,
	Daniel Kurtz <djkurtz@...gle.com>,
	Tomasz Figa <tfiga@...gle.com>,
	Lucas Stach <l.stach@...gutronix.de>,
	Rob Herring <robh+dt@...nel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	linux-mediatek@...ts.infradead.org,
	Sasha Hauer <kernel@...gutronix.de>,
	srv_heupstream@...iatek.com, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	iommu@...ts.linux-foundation.org, pebolle@...cali.nl,
	arnd@...db.de, mitchelh@...eaurora.org, p.zabel@...gutronix.de,
	youhua.li@...iatek.com, k.zhang@...iatek.com,
	kendrick.hsu@...iatek.com
Subject: Re: [PATCH v7 3/5] memory: mediatek: Add SMI driver



On 18/12/15 09:09, Yong Wu wrote:
> This patch add SMI(Smart Multimedia Interface) driver. This driver
> is responsible to enable/disable iommu and control the power domain
> and clocks of each local arbiter.
>
> Signed-off-by: Yong Wu <yong.wu@...iatek.com>
> ---
>   drivers/memory/Kconfig     |   8 ++
>   drivers/memory/Makefile    |   1 +
>   drivers/memory/mtk-smi.c   | 268 +++++++++++++++++++++++++++++++++++++++++++++
>   include/soc/mediatek/smi.h |  58 ++++++++++
>   4 files changed, 335 insertions(+)
>   create mode 100644 drivers/memory/mtk-smi.c
>   create mode 100644 include/soc/mediatek/smi.h
>
> diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
> index 6f31546..51d5cd2 100644
> --- a/drivers/memory/Kconfig
> +++ b/drivers/memory/Kconfig
> @@ -114,6 +114,14 @@ config JZ4780_NEMC
>   	  the Ingenic JZ4780. This controller is used to handle external
>   	  memory devices such as NAND and SRAM.
>
> +config MTK_SMI
> +	bool
> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	help
> +	  This driver is for the Memory Controller module in MediaTek SoCs,
> +	  mainly help enable/disable iommu and control the power domain and
> +	  clocks for each local arbiter.
> +
>   source "drivers/memory/tegra/Kconfig"
>
>   endif
> diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
> index 1c46af5..890bdf4 100644
> --- a/drivers/memory/Makefile
> +++ b/drivers/memory/Makefile
> @@ -15,5 +15,6 @@ obj-$(CONFIG_FSL_IFC)		+= fsl_ifc.o
>   obj-$(CONFIG_MVEBU_DEVBUS)	+= mvebu-devbus.o
>   obj-$(CONFIG_TEGRA20_MC)	+= tegra20-mc.o
>   obj-$(CONFIG_JZ4780_NEMC)	+= jz4780-nemc.o
> +obj-$(CONFIG_MTK_SMI)		+= mtk-smi.o
>
>   obj-$(CONFIG_TEGRA_MC)		+= tegra/
> diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
> new file mode 100644
> index 0000000..3714f604
> --- /dev/null
> +++ b/drivers/memory/mtk-smi.c
> @@ -0,0 +1,268 @@
> +/*
> + * Copyright (c) 2014-2015 MediaTek Inc.
> + * Author: Yong Wu <yong.wu@...iatek.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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +#include <linux/clk.h>
> +#include <linux/component.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <soc/mediatek/smi.h>
> +
> +#define SMI_LARB_MMU_EN		0xf00
> +
> +struct mtk_smi {
> +	struct device	*dev;
> +	struct clk	*clk_apb, *clk_smi;
> +};
> +
> +struct mtk_smi_larb { /* larb: local arbiter */
> +	struct mtk_smi  smi;
> +	void __iomem	*base;
> +	struct device	*smi_common_dev;
> +	u32		*mmu;
> +};
> +
> +static int mtk_smi_enable(const struct mtk_smi *smi)
> +{
> +	int ret;
> +
> +	ret = pm_runtime_get_sync(smi->dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = clk_prepare_enable(smi->clk_apb);
> +	if (ret)
> +		goto err_put_pm;
> +
> +	ret = clk_prepare_enable(smi->clk_smi);
> +	if (ret)
> +		goto err_disable_apb;
> +
> +	return 0;
> +
> +err_disable_apb:
> +	clk_disable_unprepare(smi->clk_apb);
> +err_put_pm:
> +	pm_runtime_put_sync(smi->dev);
> +	return ret;
> +}
> +
> +static void mtk_smi_disable(const struct mtk_smi *smi)
> +{
> +	clk_disable_unprepare(smi->clk_smi);
> +	clk_disable_unprepare(smi->clk_apb);
> +	pm_runtime_put_sync(smi->dev);
> +}
> +
> +int mtk_smi_larb_get(struct device *larbdev)
> +{
> +	struct mtk_smi_larb *larb = dev_get_drvdata(larbdev);
> +	struct mtk_smi *common = dev_get_drvdata(larb->smi_common_dev);
> +	int ret;
> +
> +	/* Enable the smi-common's power and clocks */
> +	ret = mtk_smi_enable(common);
> +	if (ret)
> +		return ret;
> +
> +	/* Enable the larb's power and clocks */
> +	ret = mtk_smi_enable(&larb->smi);
> +	if (ret) {
> +		mtk_smi_disable(common);
> +		return ret;
> +	}
> +
> +	/* Configure the iommu info */
> +	if (larb->mmu)
> +		writel(*larb->mmu, larb->base + SMI_LARB_MMU_EN);

Can there be a larb that does not have a mmu id defined?
Phandles for the iommu need always to have a mtk_m4u_id defined, so I 
don't see the case where this can happen?

Why did you changed this value to a pointer and added the if?

> +
> +	return 0;
> +}
> +
> +void mtk_smi_larb_put(struct device *larbdev)
> +{
> +	struct mtk_smi_larb *larb = dev_get_drvdata(larbdev);
> +	struct mtk_smi *common = dev_get_drvdata(larb->smi_common_dev);
> +

Would it make sense to write SMI_LARB_MMU_EN here again to eventually 
turn off mmus?

Other then this, the driver looks fine to me.

Regards,
Matthias

> +	mtk_smi_disable(&larb->smi);
> +	mtk_smi_disable(common);
> +}
> +
> +static int
> +mtk_smi_larb_bind(struct device *dev, struct device *master, void *data)
> +{
> +	struct mtk_smi_larb *larb = dev_get_drvdata(dev);
> +	struct mtk_smi_iommu *smi_iommu = data;
> +	unsigned int         i;
> +
> +	for (i = 0; i < smi_iommu->larb_nr; i++) {
> +		if (dev == smi_iommu->larb_imu[i].dev) {
> +			larb->mmu = &smi_iommu->larb_imu[i].mmu;
> +			return 0;
> +		}
> +	}
> +	return -ENODEV;
> +}
> +
> +static void
> +mtk_smi_larb_unbind(struct device *dev, struct device *master, void *data)
> +{
> +	struct mtk_smi_larb *larb = dev_get_drvdata(dev);
> +
> +	larb->mmu = NULL;
> +}
> +
> +static const struct component_ops mtk_smi_larb_component_ops = {
> +	.bind = mtk_smi_larb_bind,
> +	.unbind = mtk_smi_larb_unbind,
> +};
> +
> +static int mtk_smi_larb_probe(struct platform_device *pdev)
> +{
> +	struct mtk_smi_larb *larb;
> +	struct resource *res;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *smi_node;
> +	struct platform_device *smi_pdev;
> +
> +	if (!dev->pm_domain)
> +		return -EPROBE_DEFER;
> +
> +	larb = devm_kzalloc(dev, sizeof(*larb), GFP_KERNEL);
> +	if (!larb)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	larb->base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(larb->base))
> +		return PTR_ERR(larb->base);
> +
> +	larb->smi.clk_apb = devm_clk_get(dev, "apb");
> +	if (IS_ERR(larb->smi.clk_apb))
> +		return PTR_ERR(larb->smi.clk_apb);
> +
> +	larb->smi.clk_smi = devm_clk_get(dev, "smi");
> +	if (IS_ERR(larb->smi.clk_smi))
> +		return PTR_ERR(larb->smi.clk_smi);
> +	larb->smi.dev = dev;
> +
> +	smi_node = of_parse_phandle(dev->of_node, "mediatek,smi", 0);
> +	if (!smi_node)
> +		return -EINVAL;
> +
> +	smi_pdev = of_find_device_by_node(smi_node);
> +	of_node_put(smi_node);
> +	if (smi_pdev) {
> +		larb->smi_common_dev = &smi_pdev->dev;
> +	} else {
> +		dev_err(dev, "Failed to get the smi_common device\n");
> +		return -EINVAL;
> +	}
> +
> +	pm_runtime_enable(dev);
> +	platform_set_drvdata(pdev, larb);
> +	return component_add(dev, &mtk_smi_larb_component_ops);
> +}
> +
> +static int mtk_smi_larb_remove(struct platform_device *pdev)
> +{
> +	pm_runtime_disable(&pdev->dev);
> +	component_del(&pdev->dev, &mtk_smi_larb_component_ops);
> +	return 0;
> +}
> +
> +static const struct of_device_id mtk_smi_larb_of_ids[] = {
> +	{ .compatible = "mediatek,mt8173-smi-larb",},
> +	{}
> +};
> +
> +static struct platform_driver mtk_smi_larb_driver = {
> +	.probe	= mtk_smi_larb_probe,
> +	.remove = mtk_smi_larb_remove,
> +	.driver	= {
> +		.name = "mtk-smi-larb",
> +		.of_match_table = mtk_smi_larb_of_ids,
> +	}
> +};
> +
> +static int mtk_smi_common_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mtk_smi *common;
> +
> +	if (!dev->pm_domain)
> +		return -EPROBE_DEFER;
> +
> +	common = devm_kzalloc(dev, sizeof(*common), GFP_KERNEL);
> +	if (!common)
> +		return -ENOMEM;
> +	common->dev = dev;
> +
> +	common->clk_apb = devm_clk_get(dev, "apb");
> +	if (IS_ERR(common->clk_apb))
> +		return PTR_ERR(common->clk_apb);
> +
> +	common->clk_smi = devm_clk_get(dev, "smi");
> +	if (IS_ERR(common->clk_smi))
> +		return PTR_ERR(common->clk_smi);
> +
> +	pm_runtime_enable(dev);
> +	platform_set_drvdata(pdev, common);
> +	return 0;
> +}
> +
> +static int mtk_smi_common_remove(struct platform_device *pdev)
> +{
> +	pm_runtime_disable(&pdev->dev);
> +	return 0;
> +}
> +
> +static const struct of_device_id mtk_smi_common_of_ids[] = {
> +	{ .compatible = "mediatek,mt8173-smi-common", },
> +	{}
> +};
> +
> +static struct platform_driver mtk_smi_common_driver = {
> +	.probe	= mtk_smi_common_probe,
> +	.remove = mtk_smi_common_remove,
> +	.driver	= {
> +		.name = "mtk-smi-common",
> +		.of_match_table = mtk_smi_common_of_ids,
> +	}
> +};
> +
> +static int __init mtk_smi_init(void)
> +{
> +	int ret;
> +
> +	ret = platform_driver_register(&mtk_smi_common_driver);
> +	if (ret != 0) {
> +		pr_err("Failed to register SMI driver\n");
> +		return ret;
> +	}
> +
> +	ret = platform_driver_register(&mtk_smi_larb_driver);
> +	if (ret != 0) {
> +		pr_err("Failed to register SMI-LARB driver\n");
> +		goto err_unreg_smi;
> +	}
> +	return ret;
> +
> +err_unreg_smi:
> +	platform_driver_unregister(&mtk_smi_common_driver);
> +	return ret;
> +}
> +subsys_initcall(mtk_smi_init);
> diff --git a/include/soc/mediatek/smi.h b/include/soc/mediatek/smi.h
> new file mode 100644
> index 0000000..6ab11fa
> --- /dev/null
> +++ b/include/soc/mediatek/smi.h
> @@ -0,0 +1,58 @@
> +/*
> + * Copyright (c) 2014-2015 MediaTek Inc.
> + * Author: Yong Wu <yong.wu@...iatek.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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +#ifndef MTK_IOMMU_SMI_H
> +#define MTK_IOMMU_SMI_H
> +
> +#include <linux/bitops.h>
> +#include <linux/device.h>
> +
> +#ifdef CONFIG_MTK_SMI
> +
> +#define MTK_LARB_NR_MAX		8
> +
> +#define MTK_SMI_MMU_EN(port)	BIT(port)
> +
> +struct mtk_smi_larb_iommu {
> +	struct device *dev;
> +	unsigned int   mmu;
> +};
> +
> +struct mtk_smi_iommu {
> +	unsigned int larb_nr;
> +	struct mtk_smi_larb_iommu larb_imu[MTK_LARB_NR_MAX];
> +};
> +
> +/*
> + * mtk_smi_larb_get: Enable the power domain and clocks for this local arbiter.
> + *                   It also initialize some basic setting(like iommu).
> + * mtk_smi_larb_put: Disable the power domain and clocks for this local arbiter.
> + * Both should be called in non-atomic context.
> + *
> + * Returns 0 if successful, negative on failure.
> + */
> +int mtk_smi_larb_get(struct device *larbdev);
> +void mtk_smi_larb_put(struct device *larbdev);
> +
> +#else
> +
> +static inline int mtk_smi_larb_get(struct device *larbdev)
> +{
> +	return 0;
> +}
> +
> +static inline void mtk_smi_larb_put(struct device *larbdev) { }
> +
> +#endif
> +
> +#endif
>

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