Re: [PATCH v2 15/19] media: imx: Add MIPI CSI-2 Receiver subdev driver

[Steve Longerbeam <slongerbeam@gmail.com>]

On 01/04/2017 07:05 AM, Vladimir Zapolskiy wrote:
> On 01/03/2017 10:57 PM, Steve Longerbeam wrote:
>> Adds MIPI CSI-2 Receiver subdev driver. This subdev is required
>> for sensors with a MIPI CSI2 interface.
>>
>> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
>> ---
>>   drivers/staging/media/imx/Makefile        |   1 +
>>   drivers/staging/media/imx/imx-mipi-csi2.c | 509 ++++++++++++++++++++++++++++++
>>   2 files changed, 510 insertions(+)
>>   create mode 100644 drivers/staging/media/imx/imx-mipi-csi2.c
>>
>> diff --git a/drivers/staging/media/imx/Makefile b/drivers/staging/media/imx/Makefile
>> index fe9e992..0decef7 100644
>> --- a/drivers/staging/media/imx/Makefile
>> +++ b/drivers/staging/media/imx/Makefile
>> @@ -9,3 +9,4 @@ obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-ic.o
>>   obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-csi.o
>>   obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-smfc.o
>>   obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-camif.o
>> +obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-mipi-csi2.o
>> diff --git a/drivers/staging/media/imx/imx-mipi-csi2.c b/drivers/staging/media/imx/imx-mipi-csi2.c
>> new file mode 100644
>> index 0000000..84df16e
>> --- /dev/null
>> +++ b/drivers/staging/media/imx/imx-mipi-csi2.c
>> @@ -0,0 +1,509 @@
>> +/*
>> + * MIPI CSI-2 Receiver Subdev for Freescale i.MX5/6 SOC.
>> + *
>> + * Copyright (c) 2012-2014 Mentor Graphics Inc.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + */
>> +#include <linux/module.h>
>> +#include <linux/export.h>
>> +#include <linux/types.h>
>> +#include <linux/init.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/err.h>
>> +#include <linux/delay.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/clk.h>
>> +#include <linux/list.h>
>> +#include <linux/irq.h>
>> +#include <linux/of_device.h>
>> +#include <media/v4l2-device.h>
>> +#include <media/v4l2-of.h>
>> +#include <media/v4l2-subdev.h>
>> +#include <media/v4l2-async.h>
> Please sort the list of headers alphabetically.

done.

>
>> +#include <asm/mach/irq.h>
> Why do you need to include this header?

good question. In fact this include list was in need of a lot of pruning,
so I paired it down to the essentials.

>> +static int imxcsi2_s_stream(struct v4l2_subdev *sd, int enable)
>> +{
>> +	struct imxcsi2_dev *csi2 = sd_to_dev(sd);
>> +	int i, ret = 0;
>> +
>> +	if (!csi2->src_sd)
>> +		return -EPIPE;
>> +	for (i = 0; i < CSI2_NUM_SRC_PADS; i++) {
>> +		if (csi2->sink_sd[i])
>> +			break;
>> +	}
>> +	if (i >= CSI2_NUM_SRC_PADS)
>> +		return -EPIPE;
>> +
>> +	v4l2_info(sd, "stream %s\n", enable ? "ON" : "OFF");
>> +
>> +	if (enable && !csi2->stream_on) {
>> +		clk_prepare_enable(csi2->pix_clk);
> It can complicate the design for you, but in general clk_prepare_enable()
> can return an error.

I added an error check and reorganized a little.

>> +
>> +static int imxcsi2_parse_endpoints(struct imxcsi2_dev *csi2)
>> +{
>> +	struct device_node *node = csi2->dev->of_node;
>> +	struct device_node *epnode;
>> +	struct v4l2_of_endpoint ep;
>> +	int ret = 0;
>> +
>> +	epnode = of_graph_get_next_endpoint(node, NULL);
>> +	if (!epnode) {
>> +		v4l2_err(&csi2->sd, "failed to get endpoint node\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	v4l2_of_parse_endpoint(epnode, &ep);
> Do of_node_put(epnode) here and remove 'out' goto label.

done.

>> +static const struct of_device_id imxcsi2_dt_ids[] = {
>> +	{ .compatible = "fsl,imx-mipi-csi2", },
>> +	{ /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, imxcsi2_dt_ids);
>> +
>> +static struct platform_driver imxcsi2_driver = {
>> +	.driver = {
>> +		.name = DEVICE_NAME,
>> +		.owner = THIS_MODULE,
> Please drop .owner assignment.

done.


Steve