On Fri, Mar 06, 2015 at 06:48:16PM +0800, yong.wu at mediatek.com wrote:

From: Yong Wu <yong.wu@mediatek.com>

    This patch add SMI(Smart Multimedia Interface) driver. This driver is
responsible to enable/disable iommu and control the clocks of each
local arbiter.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/soc/mediatek/Kconfig      |   7 ++
 drivers/soc/mediatek/Makefile     |   1 +
 drivers/soc/mediatek/mt8173-smi.c | 143 ++++++++++++++++++++++++++++++++++++++
 include/linux/mtk-smi.h           |  40 +++++++++++

I just posted the power domain driver for prividing the domains this
driver uses. You should base your code on that.

+#include <linux/mm.h>
+
+#define SMI_LARB_MMU_EN                 (0xf00)
+#define F_SMI_MMU_EN(port)              (1 << (port))
+
+struct mtk_smi_larb {
+	void __iomem *larb_base;
+	struct clk *larb_clk[3];/* each larb has 3 clk at most */
+};
+
+static const char * const mtk_smi_clk_name[] = {
+	"larb_sub0", "larb_sub1", "larb_sub2"
+};
+
+static const struct of_device_id mtk_smi_of_ids[] = {
+	{ .compatible = "mediatek,mt8173-smi-larb",
+	},

Add a newline after the opening brace.

+int mtk_smi_config_port(struct platform_device *plarbdev,
+			unsigned int larbportid)
+{
+	struct mtk_smi_larb *larbpriv = dev_get_drvdata(&plarbdev->dev);
+	int ret;
+	u32 reg;
+
+	ret = mtk_smi_larb_get(plarbdev);
+	if (ret)
+		return ret;
+
+	reg = readl(larbpriv->larb_base + SMI_LARB_MMU_EN);
+	reg &= ~F_SMI_MMU_EN(larbportid);
+	reg |= F_SMI_MMU_EN(larbportid);

This sets the very same bits that are cleared one line above. This is
surely not what you want.

+	writel(reg, larbpriv->larb_base + SMI_LARB_MMU_EN);
+
+	mtk_smi_larb_put(plarbdev);
+
+	return 0;
+}
+
+static int mtk_smi_probe(struct platform_device *pdev)
+{
+	struct mtk_smi_larb *larbpriv;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	unsigned int i;
+
+	larbpriv = devm_kzalloc(dev, sizeof(struct mtk_smi_larb), GFP_KERNEL);

sizeof(*larbpriv)

+	if (!larbpriv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	larbpriv->larb_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(larbpriv->larb_base)) {
+		dev_err(dev, "larbbase %p err\n", larbpriv->larb_base);

You can print an error number with %ld and PTR_ERR(larbpriv->larb_base).
Printing the pointer is not that helpful.

+/*
+ * Enable iommu for each port, it is only for iommu.
+ *
+ * Returns 0 if successfully, others if failed.
+ */
+int mtk_smi_config_port(struct platform_device *pdev,
+			unsigned int larbportid);
+
+/*
+ * The multimedia module should call the two function below
+ * which help open/close the clock of the larb.
+ * so the client dtsi should add the larb like "larb = <&larb0>"
+ * to get platform_device.
+ *
+ * mtk_smi_larb_get should be called before the multimedia h/w work.
+ * mtk_smi_larb_put should be called after h/w done.
+ *
+ * Returns 0 if successfully, others if failed.
+ */
+int mtk_smi_larb_get(struct platform_device *plarbdev);
+void mtk_smi_larb_put(struct platform_device *plarbdev);

The function documentation usually comes with the definition of a
function, not its declaration.

Sascha

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