Re: [PATCH v7 3/5] memory: mediatek: Add SMI driver

From: Matthias Brugger
Date: Mon Jan 18 2016 - 05:11:47 EST




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@xxxxxxxxxxxx>
---
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@xxxxxxxxxxxx>
+ *
+ * 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@xxxxxxxxxxxx>
+ *
+ * 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