Re: [PATCH v3 02/13] [media] mtk-mipicsi: add mediatek mipicsi driver for mt2712

CK Hu
2019-05-17T07:37:49Z

Hi, Stu:

On Tue, 2019-05-14 at 14:13 +0800, Stu Hsieh wrote:
> This patch add mediatek mipicsi driver for mt2712,
> including probe function to get the value from device tree,
> and register to v4l2 the host device.
>
> Signed-off-by: Stu Hsieh <stu.hsieh@mediatek.com>
> ---
> drivers/media/platform/mtk-mipicsi/Makefile | 4 +
> .../media/platform/mtk-mipicsi/mtk_mipicsi.c | 587 ++++++++++++++++++
> 2 files changed, 591 insertions(+)
> create mode 100644 drivers/media/platform/mtk-mipicsi/Makefile
> create mode 100644 drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c
>
> diff --git a/drivers/media/platform/mtk-mipicsi/Makefile b/drivers/media/platform/mtk-mipicsi/Makefile
> new file mode 100644
> index 000000000000..326a5e3808fa
> --- /dev/null
> +++ b/drivers/media/platform/mtk-mipicsi/Makefile
> @@ -0,0 +1,4 @@
> +mtk-mipicsi-y += mtk_mipicsi.o
> +
> +obj-$(CONFIG_VIDEO_MEDIATEK_MIPICSI) += mtk-mipicsi.o
> +
> diff --git a/drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c b/drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c
> new file mode 100644
> index 000000000000..4ae5b88abc5f
> --- /dev/null
> +++ b/drivers/media/platform/mtk-mipicsi/mtk_mipicsi.c
> @@ -0,0 +1,587 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2017 MediaTek Inc.
> + * Author: Ricky Zhang <ricky.zhang@mediatek.com>
> + * Baoyin Zhang <baoyin.zhang@mediatek.com>
> + * Alan Yue <alan.yue@mediatek.com>
> + * Stu Hsieh <stu.hsieh@mediatek.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
> + * http://www.gnu.org/licenses/gpl-2.0.html for more details.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/errno.h>
> +#include <linux/fs.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/moduleparam.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/iommu.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-dev.h>
> +#include <media/videobuf2-dma-contig.h>
> +#include <media/soc_camera.h>
> +#include <media/drv-intf/soc_mediabus.h>
> +#include <media/videobuf2-core.h>
> +#include <linux/videodev2.h>
> +#include <soc/mediatek/smi.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +
> +#define MTK_MIPICSI_DRV_NAME "mtk-mipicsi"
> +#define MTK_PLATFORM_STR "platform:mt2712"
> +#define MIPICSI_COMMON_CLK 2
> +#define MTK_CAMDMA_MAX_NUM 4U
> +#define MIPICSI_CLK (MIPICSI_COMMON_CLK + MTK_CAMDMA_MAX_NUM)
> +
> +#define MIPI_RX_ANA00_CSI 0x00
> +#define MIPI_RX_ANA04_CSI 0x04
> +#define MIPI_RX_ANA08_CSI 0x08
> +#define MIPI_RX_ANA0C_CSI 0x0c
> +#define MIPI_RX_ANA10_CSI 0x10
> +#define MIPI_RX_ANA20_CSI 0x20
> +#define MIPI_RX_ANA24_CSI 0x24
> +#define MIPI_RX_ANA4C_CSI 0x4c
> +#define MIPI_RX_ANA50_CSI 0x50
> +
> +#define SENINF_CTRL 0x00
> +
> +#define SENINF_NCSI2_CAL_24 0x24
> +#define SENINF_NCSI2_CAL_38 0x38
> +#define SENINF_NCSI2_CAL_3C 0x3C
> +#define SENINF_NCSI2_CTL 0xA0
> +#define SENINF_NCSI2_LNRD_TIMING 0xA8
> +#define SENINF_NCSI2_INT_EN 0xB0
> +#define SENINF_NCSI2_INT_STATUS 0xB4
> +#define SENINF_NCSI2_DBG_SEL 0xB8
> +#define SENINF_NCSI2_HSRX_DBG 0xD8
> +#define SENINF_NCSI2_DI 0xDC
> +#define SENINF_NCSI2_DI_CTRL 0xE4
> +
> +#define SENINF_TOP_CTRL 0x00
> +#define SENINF_TOP_CMODEL_PAR 0x04
> +#define SENINF_TOP_MUX 0x08
> +
> +#define SENINF_MUX_CTRL 0x00
> +
> +#define CAMSV_MODULE_EN 0x10
> +#define CAMSV_FMT_SEL 0x14
> +#define CAMSV_INT_EN 0x18
> +#define CAMSV_CLK_EN 0x30
> +
> +#define CAMSV_TG_SEN_MODE 0x500
> +#define CAMSV_TG_SEN_GRAB_PXL 0x508
> +#define CAMSV_TG_SEN_GRAB_LIN 0x50C
> +#define CAMSV_TG_PATH_CFG 0x510
> +
> +#define IMGO_XSIZE 0x230
> +#define IMGO_YSIZE 0x234
> +#define IMGO_STRIDE 0x238
> +#define DMA_FRAME_HEADER_EN 0xE00
> +
> +struct mtk_mipicsi_dev {
> + struct platform_device *pdev;
> + unsigned int camsv_num;
> + struct device *larb_pdev;
> + void __iomem *ana;
> + void __iomem *seninf_ctrl;
> + void __iomem *seninf;
> + struct regmap *seninf_top;
> + void __iomem *seninf_mux[MTK_CAMDMA_MAX_NUM];
> + void __iomem *camsv[MTK_CAMDMA_MAX_NUM];
> + int clk_num;
> + struct clk *clk[MIPICSI_CLK];
> +};
> +
> +#define MTK_MIPICSI_BUS_PARAM (V4L2_MBUS_MASTER | \
> + V4L2_MBUS_HSYNC_ACTIVE_HIGH | \
> + V4L2_MBUS_HSYNC_ACTIVE_LOW | \
> + V4L2_MBUS_VSYNC_ACTIVE_HIGH | \
> + V4L2_MBUS_VSYNC_ACTIVE_LOW | \
> + V4L2_MBUS_PCLK_SAMPLE_RISING | \
> + V4L2_MBUS_PCLK_SAMPLE_FALLING | \
> + V4L2_MBUS_DATA_ACTIVE_HIGH)
> +
> +static void mtk_mipicsi_ana_init(void __iomem *base)
> +{
> + writel(0xFEFBEFBEU & readl(base + MIPI_RX_ANA4C_CSI),
> + base + MIPI_RX_ANA4C_CSI);
> + writel(0xFEFBEFBEU & readl(base + MIPI_RX_ANA50_CSI),
> + base + MIPI_RX_ANA50_CSI);
> +
> + /* clock lane and lane0-lane3 input select */
> + writel(8UL | readl(base + MIPI_RX_ANA00_CSI),
> + base + MIPI_RX_ANA00_CSI);
> + writel(8UL | readl(base + MIPI_RX_ANA04_CSI),
> + base + MIPI_RX_ANA04_CSI);
> + writel(8UL | readl(base + MIPI_RX_ANA08_CSI),
> + base + MIPI_RX_ANA08_CSI);
> + writel(8UL | readl(base + MIPI_RX_ANA0C_CSI),
> + base + MIPI_RX_ANA0C_CSI);
> + writel(8UL | readl(base + MIPI_RX_ANA10_CSI),
> + base + MIPI_RX_ANA10_CSI);
> +
> + /* BG chopper clock and CSI BG enable */
> + writel(11UL | readl(base + MIPI_RX_ANA24_CSI),
> + base + MIPI_RX_ANA24_CSI);
> + mdelay(1);
> +
> + /* LDO core bias enable */
> + writel(0xFF030003U | readl(base + MIPI_RX_ANA20_CSI),
> + base + MIPI_RX_ANA20_CSI);
> + mdelay(1);
> +}
> +
> +static void mtk_mipicsi_seninf_ctrl_init(void __iomem *base)
> +{
> + /*seninf enable. select NCSI2 as seninif input source */
> + writel(0x8001U, base + SENINF_CTRL);
> +}
> +
> +static void mtk_mipicsi_seninf_init(void __iomem *base)
> +{
> + writel(1U, base + SENINF_NCSI2_CAL_38);
> + writel(0x00051545U, base + SENINF_NCSI2_CAL_3C);
> + writel(5U, base + SENINF_NCSI2_CAL_38);
> + mdelay(1);
> + writel(4U, base + SENINF_NCSI2_CAL_38);
> + writel(0U, base + SENINF_NCSI2_CAL_3C);
> + writel(0x11U, base + SENINF_NCSI2_DBG_SEL);
> + writel(0x189617FU, base + SENINF_NCSI2_CTL);
> + writel(~(1UL << 27) & readl(base + SENINF_NCSI2_CTL),
> + base + SENINF_NCSI2_CTL);
> + writel((1UL << 27) | readl(base + SENINF_NCSI2_CTL),
> + base + SENINF_NCSI2_CTL);
> + writel(0x2800U, base + SENINF_NCSI2_LNRD_TIMING);
> + writel(0x7FFFU, base + SENINF_NCSI2_INT_STATUS);
> + writel(0x7FCFFFFEU, base + SENINF_NCSI2_INT_EN);
> + writel(0xE4000000U, base + SENINF_NCSI2_CAL_24);
> + writel(0xFFFFFF00U & readl(base + SENINF_NCSI2_DBG_SEL),
> + base + SENINF_NCSI2_DBG_SEL);
> + writel(0xFFFFFF45U | readl(base + SENINF_NCSI2_DBG_SEL),
> + base + SENINF_NCSI2_DBG_SEL);
> + writel(0xFFFFFFEFU & readl(base + SENINF_NCSI2_HSRX_DBG),
> + base + SENINF_NCSI2_HSRX_DBG);
> + writel(0x01010101U, base + SENINF_NCSI2_DI_CTRL);
> + writel(0x03020100U, base + SENINF_NCSI2_DI);
> + writel(0x10, base + SENINF_NCSI2_DBG_SEL);
> +}
> +
> +static void mtk_mipicsi_seninf_top_init(struct regmap *regmap)
> +{
> + (void)regmap_write(regmap, SENINF_TOP_CTRL, 0x00010C00U);
> + (void)regmap_write(regmap, SENINF_TOP_CMODEL_PAR, 0x00079871);
> + (void)regmap_write(regmap, SENINF_TOP_MUX, 0x11110000);

If the function has return error, why don't you handle the error?

> +}
> +
> +static void mtk_mipicsi_seninf_mux_init(void __iomem *base, unsigned int ch)
> +{
> + unsigned int mux_ctrl_val = (((0x9EFF8U + ch) << 12U) | 0x180U);
> +
> + /* select seninf_mux1-4 as input for NCSI2 VC0-3*/
> + writel(mux_ctrl_val, base + SENINF_MUX_CTRL);
> +}
> +
> +static void mtk_mipicsi_camsv_csr_init(void __iomem *base)
> +{
> + /* double buffer enable. IMGO enable. PAK sel. TG enable */
> + writel(0x40000019U, base + CAMSV_MODULE_EN);
> + /* IMGO DP, PAK DP and TG clk enable */
> + writel(0x00008005U, base + CAMSV_CLK_EN);
> + /* 0: raw8, 1:raw10, 2:raw12, 3:YUV422, 4:raw14, 7:JPEG */
> + writel(0x00000003U, base + CAMSV_FMT_SEL);
> + /* write clear enable. pass1 down interrupt enable */
> + writel(0x80000400U, base + CAMSV_INT_EN);
> +}
> +
> +static void mtk_mipicsi_camsv_tg_init(void __iomem *base, u32 b, u32 h)
> +{
> + /* bit[30:16] grab end pixel clock number.
> + * bit[14:0] grab start pixel clock number
> + */
> + writel(b << 16U, base + CAMSV_TG_SEN_GRAB_PXL);
> + /* bit[29:16] end line number. bit[13:0] start line number */
> + writel(h << 16U, base + CAMSV_TG_SEN_GRAB_LIN);
> + /* YUV sensor unsigned to signed enable */
> + writel(0x1000U, base + CAMSV_TG_PATH_CFG);
> + /* cmos enable YUV422 mode */
> + writel(3U, base + CAMSV_TG_SEN_MODE);
> +}
> +
> +static void mtk_mipicsi_camsv_dma_init(void __iomem *base, u32 b, u32 h)
> +{
> + /* enable SW format setting. YUV format. 16bit */
> + writel(0x01810000U | b, base + IMGO_STRIDE);
> + /* b -1 bytes per line to write */
> + writel(b - 1U, base + IMGO_XSIZE);
> + /* w - 1 lines to write */
> + writel(h - 1U, base + IMGO_YSIZE);
> + /* disable frame header function */
> + writel(0U, base + DMA_FRAME_HEADER_EN);
> +}
> +
> +static void mtk_mipicsi_camsv_init(void __iomem *base, u32 b, u32 h)
> +{
> + mtk_mipicsi_camsv_csr_init(base);
> + mtk_mipicsi_camsv_tg_init(base, b, h);
> + mtk_mipicsi_camsv_dma_init(base, b, h);
> +}
> +
> +static void mtk_mipicsi_reg_init(struct mtk_mipicsi_dev *mipicsi)
> +{
> + unsigned int i;
> +
> + mtk_mipicsi_ana_init(mipicsi->ana);
> + mtk_mipicsi_seninf_ctrl_init(mipicsi->seninf_ctrl);
> + mtk_mipicsi_seninf_init(mipicsi->seninf);
> + mtk_mipicsi_seninf_top_init(mipicsi->seninf_top);
> +
> + for (i = 0U; i < mipicsi->camsv_num; ++i) {
> + u32 b = mipicsi->bytesperline;
> + u32 h = mipicsi->height;
> +
> + mtk_mipicsi_seninf_mux_init(mipicsi->seninf_mux[i], i);
> + mtk_mipicsi_camsv_init(mipicsi->camsv[i], b, h);
> + }
> +}
> +
> +static int mtk_mipicsi_pm_suspend(struct device *dev)
> +{
> + struct mtk_mipicsi_dev *mipicsi = dev_get_drvdata(dev);
> + int ret = 0;
> + int i = 0;
> +
> + /* close digtal and analog clock */
> + for (i = 0; i < mipicsi->clk_num; ++i)
> + clk_disable_unprepare(mipicsi->clk[i]);
> +
> + if (mipicsi->larb_pdev != NULL)
> + mtk_smi_larb_put(mipicsi->larb_pdev);
> +
> + return ret;
> +}
> +
> +static int mtk_mipicsi_suspend(struct device *dev)
> +{
> + if (pm_runtime_suspended(dev))
> + return 0;
> +
> + return mtk_mipicsi_pm_suspend(dev);
> +}
> +
> +static int mtk_mipicsi_pm_resume(struct device *dev)
> +{
> + struct mtk_mipicsi_dev *mipicsi = dev_get_drvdata(dev);
> + int ret = 0;
> + int i = 0;
> +
> + if (mipicsi->larb_pdev != NULL) {
> + ret = mtk_smi_larb_get(mipicsi->larb_pdev);
> + if (ret != 0)
> + return ret;
> + }
> +
> + /* enable digtal clock */
> + for (i = 0; i < mipicsi->clk_num; ++i)
> + (void)clk_prepare_enable(mipicsi->clk[i]);

If the function return error, why don't you handle the error?

> +
> + mtk_mipicsi_reg_init(mipicsi);
> + return ret;
> +}
> +
> +static int mtk_mipicsi_resume(struct device *dev)
> +{
> + if (pm_runtime_suspended(dev))
> + return 0;
> +
> + return mtk_mipicsi_pm_resume(dev);
> +}
> +
> +static const struct dev_pm_ops mtk_mipicsi_pm = {
> + SET_SYSTEM_SLEEP_PM_OPS(mtk_mipicsi_suspend, mtk_mipicsi_resume)
> + SET_RUNTIME_PM_OPS(mtk_mipicsi_pm_suspend,
> + mtk_mipicsi_pm_resume, NULL)
> +};
> +
> +static int seninf_mux_camsv_node_parse(struct mtk_mipicsi_dev *mipicsi,
> + int index)
> +{
> + struct clk *clk = NULL;
> + struct device *dev = NULL;
> + struct resource *res = NULL;
> + struct platform_device *camdma_pdev = NULL;
> + struct platform_device *pdev = NULL;
> + struct device_node *np = NULL;
> +
> + if (mipicsi == NULL)

Why mipicsi is NULL?

> + return -EINVAL;
> +
> + dev = &mipicsi->pdev->dev;
> + pdev = mipicsi->pdev;

Why do you need pdev?

> +
> + np = of_parse_phandle(dev->of_node,
> + "mediatek,seninf_mux_camsv", index);
> + if (np == NULL) {
> + dev_err(dev, "no NO.%d mediatek,seninf_mux_camsv node\n",
> + index);
> + return -ENODEV;
> + }
> +
> + camdma_pdev = of_find_device_by_node(np);
> + of_node_put(np);
> + if (camdma_pdev == NULL) {
> + camdma_pdev = of_platform_device_create(np, NULL,
> + platform_bus_type.dev_root);

I don't know why do you do this? Could you explain?

> + if (camdma_pdev == NULL)
> + return -EPROBE_DEFER;
> + }
> +
> + clk = of_clk_get(np, 0);
> + if (clk == NULL) {
> + dev_err(dev, "get clk fail in %s node\n", np->full_name);
> + return -ENODEV;
> + }
> + mipicsi->clk[index] = clk;
> +
> + res = platform_get_resource(camdma_pdev, IORESOURCE_MEM, 0);
> + if (res == NULL) {
> + dev_err(dev, "get seninf_mux memory failed in %s node\n",
> + np->full_name);
> + return -ENODEV;
> + }
> + mipicsi->seninf_mux[index] =
> + devm_ioremap_resource(&camdma_pdev->dev, res);
> +
> + res = platform_get_resource(camdma_pdev, IORESOURCE_MEM, 1);
> + if (res == NULL) {
> + dev_err(dev, "get camsv memory failed in %s node\n",
> + np->full_name);
> + return -ENODEV;
> + }
> + mipicsi->camsv[index] =
> + devm_ioremap_resource(&camdma_pdev->dev, res);

In your design, camsv is just a resource device without the driver to
control it. The control flow is placed in mipicsi driver. I would like
the camsv resource is controlled by a camsv driver.

> +
> + dev_info(dev, "%s parse done\n", np->full_name);
> +
> + return 0;
> +}
> +
> +static int mtk_mipicsi_common_node_parse(struct mtk_mipicsi_dev *mipicsi,
> + struct device_node *node)
> +{
> + int i = 0;
> + struct regmap *seninf_top = NULL;
> + struct device *dev = NULL;
> + struct platform_device *pdev = NULL;
> + struct clk *clk = NULL;
> +
> + if ((mipicsi == NULL) || (node == NULL))

Why mipicsi and node is NULL?

> + return -EINVAL;
> +
> + dev = &mipicsi->pdev->dev;
> + pdev = mipicsi->pdev;

Why do you need pdev?

> +
> + /* All the mipicsi HW share the same seninf_top */
> + seninf_top = syscon_regmap_lookup_by_phandle(dev->of_node,
> + "mediatek,mipicsi");

Your design let all mipicsi device driver directly write the register of
mipicsi-common device. Why not let mipicsi-common driver provide
interface for mipicsi driver, and the register is written by
mipicsi-common driver?

> + if (seninf_top == NULL) {
> + dev_err(dev, "Missing mediadek,mipicsi in %s node\n",
> + node->full_name);
> + return -EINVAL;
> + }
> + mipicsi->seninf_top = seninf_top;
> +
> + /* get IMG_SENINF_CAM_EN and IMG_SENINF_SCAM_EN clk*/
> + mipicsi->clk_num = mipicsi->camsv_num;
> +
> + for (i = 0; i < MIPICSI_COMMON_CLK; ++i) {
> + clk = of_clk_get(node, i);
> + if (clk == NULL) {
> + dev_err(dev, "get clk fail in %s node\n",
> + node->full_name);
> + return -EINVAL;
> + }
> + mipicsi->clk[mipicsi->clk_num] = clk;
> + ++mipicsi->clk_num;
> + }
> +
> + dev_info(dev, "%s parse done\n", node->full_name);
> +
> + return 0;
> +}
> +
> +static int mtk_mipicsi_node_parse(struct mtk_mipicsi_dev *mipicsi)
> +{
> + int ret;
> + int camsv_num = 0;
> + int i;
> + struct device *dev = NULL;
> + struct resource *res = NULL;
> + struct device_node *common_node = NULL;
> + struct platform_device *pdev = NULL;
> +
> + if (mipicsi == NULL)
> + return -EINVAL;
> +
> + dev = &mipicsi->pdev->dev;
> + pdev = mipicsi->pdev;
> +
> + /* get and parse seninf_mux_camsv */
> + camsv_num = of_count_phandle_with_args(dev->of_node,
> + "mediatek,seninf_mux_camsv", NULL);
> + if (camsv_num <= 0) {
> + dev_err(dev, "no mediatek,seninf_mux_camsv\n");
> + return -EINVAL;
> + }
> + mipicsi->camsv_num = camsv_num;
> + dev_info(dev, "there are %d camsv node\n", camsv_num);
> +
> + for (i = 0; i < mipicsi->camsv_num; ++i) {
> + ret = seninf_mux_camsv_node_parse(mipicsi, i);
> + if ((ret < 0) && (ret != -EPROBE_DEFER)) {

Why don't return when ret == -EPROBE_DEFER?

> + dev_err(dev,
> + "NO.%d seninf_mux_camsv node parse fail\n", i);

I think you need not to print error message here because
seninf_mux_camsv_node_parse() has already print it.

> + return ret;
> + }
> + }
> +
> + /* get mediatek,mipicsi node and its resource */
> + common_node = of_parse_phandle(dev->of_node, "mediatek,mipicsi", 0);

You should of_node_put(common_node) somewhere.

> + if (common_node == NULL) {
> + dev_err(dev, "no mediadek,mipicsi\n");
> + return -EINVAL;
> + }
> +
> + ret = mtk_mipicsi_common_node_parse(mipicsi, common_node);
> + if (ret < 0)
> + return ret;
> +
> + /*get ana and seninf reg*/
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (res == NULL) {
> + dev_err(dev, "get ana register failed\n");
> + return -ENODEV;
> + }
> + mipicsi->ana = devm_ioremap_resource(&pdev->dev, res);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + if (res == NULL) {
> + dev_err(dev, "get seninf_ctrl register failed\n");
> + return -ENODEV;
> + }
> + mipicsi->seninf_ctrl = devm_ioremap_resource(&pdev->dev, res);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
> + if (res == NULL) {
> + dev_err(dev, "get seninf register failed\n");
> + return -ENODEV;
> + }
> + mipicsi->seninf = devm_ioremap_resource(&pdev->dev, res);
> +
> + dev_info(dev, "mipicsi node parse done\n");
> +
> + return 0;
> +}
> +
> +static int mtk_mipicsi_probe(struct platform_device *pdev)
> +{
> + struct mtk_mipicsi_dev *mipicsi = NULL;
> + int ret = 0;
> + struct iommu_domain *iommu = NULL;
> + struct device_node *larb_node = NULL;
> + struct platform_device *larb_pdev = NULL;
> +
> + iommu = iommu_get_domain_for_dev(&pdev->dev);
> + if (iommu == NULL) {
> + dev_err(&pdev->dev, "Waiting iommu driver ready...\n");
> + return -EPROBE_DEFER;
> + }
> +
> + larb_node = of_parse_phandle(pdev->dev.of_node, "mediatek,larb", 0);
> + if (larb_node == NULL) {
> + dev_err(&pdev->dev, "Missing mediadek,larb in %s node\n",
> + pdev->dev.of_node->full_name);
> + return -EINVAL;
> + }
> +
> + larb_pdev = of_find_device_by_node(larb_node);
> + if (larb_pdev == NULL || !larb_pdev->dev.driver) {
> + dev_err(&pdev->dev, "Waiting for larb device %s\n",
> + larb_node->full_name);

of_node_put(larb_node);

Regards,
CK

> + return -EPROBE_DEFER;
> + }
> + of_node_put(larb_node);
> +
> + mipicsi = devm_kzalloc(&pdev->dev, sizeof(*mipicsi), GFP_KERNEL);
> + if (mipicsi == NULL)
> + return -ENOMEM;
> +
> + mipicsi->pdev = pdev;
> + mipicsi->larb_pdev = &larb_pdev->dev;
> +
> + ret = mtk_mipicsi_node_parse(mipicsi);
> + if (ret < 0)
> + return ret;
> +
> + pm_runtime_enable(&pdev->dev);
> +
> + ret = vb2_dma_contig_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32U));
> + if (ret != 0) {
> + dev_err(&pdev->dev, "dma set max seg size fail\n");
> + goto clean;
> + }
> +
> + dev_set_drvdata(&pdev->dev, mipicsi);
> +
> + dev_info(&pdev->dev, "probe done\n");
> + return ret;
> +clean:
> + pm_runtime_disable(&pdev->dev);
> + return ret;
> +}
> +
> +static int mtk_mipicsi_remove(struct platform_device *pdev)
> +{
> + pm_runtime_disable(&pdev->dev);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id mtk_mipicsi_of_match[] = {
> + { .compatible = "mediatek,mt2712-mipicsi", },
> + {},
> +};
> +
> +static struct platform_driver mtk_mipicsi_driver = {
> + .driver = {
> + .name = MTK_MIPICSI_DRV_NAME,
> + .pm = &mtk_mipicsi_pm,
> + .of_match_table = of_match_ptr(mtk_mipicsi_of_match),
> + },
> + .probe = mtk_mipicsi_probe,
> + .remove = mtk_mipicsi_remove,
> +};
> +
> +module_platform_driver(mtk_mipicsi_driver);
> +MODULE_DESCRIPTION("MediaTek SoC Camera Host driver");
> +MODULE_LICENSE("GPL v2");