On 09/27/2012 04:07 PM, Guennadi Liakhovetski wrote:
> Add a V4L2 OF parser, implementing bindings, documented in
> Documentation/devicetree/bindings/media/v4l2.txt.
>
> Signed-off-by: Guennadi Liakhovetski<g.liakhovetski@xxxxxx>
> ---
> drivers/media/v4l2-core/Makefile | 3 +
> drivers/media/v4l2-core/v4l2-of.c | 190 +++++++++++++++++++++++++++++++++++++
> include/media/v4l2-of.h | 62 ++++++++++++
> 3 files changed, 255 insertions(+), 0 deletions(-)
> create mode 100644 drivers/media/v4l2-core/v4l2-of.c
> create mode 100644 include/media/v4l2-of.h
>
> diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile
> index c2d61d4..00f64d6 100644
> --- a/drivers/media/v4l2-core/Makefile
> +++ b/drivers/media/v4l2-core/Makefile
> @@ -9,6 +9,9 @@ videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
> ifeq ($(CONFIG_COMPAT),y)
> videodev-objs += v4l2-compat-ioctl32.o
> endif
> +ifeq ($(CONFIG_OF),y)
> + videodev-objs += v4l2-of.o
> +endif
>
> obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-int-device.o
> obj-$(CONFIG_VIDEO_V4L2) += v4l2-common.o
> diff --git a/drivers/media/v4l2-core/v4l2-of.c b/drivers/media/v4l2-core/v4l2-of.c
> new file mode 100644
> index 0000000..f45d64b
> --- /dev/null
> +++ b/drivers/media/v4l2-core/v4l2-of.c
> @@ -0,0 +1,190 @@
> +/*
> + * V4L2 OF binding parsing library
> + *
> + * Copyright (C) 2012 Renesas Electronics Corp.
> + * Author: Guennadi Liakhovetski<g.liakhovetski@xxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of version 2 of the GNU General Public License as
> + * published by the Free Software Foundation.
> + */
> +#include<linux/kernel.h>
> +#include<linux/module.h>
> +#include<linux/of.h>
> +#include<linux/types.h>
> +
> +#include<media/v4l2-of.h>
> +
> +/*
> + * All properties are optional. If none are found, we don't set any flags. This
> + * means, the port has a static configuration and no properties have to be
> + * specified explicitly.
> + * If any properties are found, that identify the bus as parallel, and
> + * slave-mode isn't set, we set V4L2_MBUS_MASTER. Similarly, if we recognise the
> + * bus as serial CSI-2 and clock-noncontinuous isn't set, we set the
> + * V4L2_MBUS_CSI2_CONTINUOUS_CLOCK flag.
> + * The caller should hold a reference to "node."
> + */
> +void v4l2_of_parse_link(const struct device_node *node,
> + struct v4l2_of_link *link)
> +{
> + const struct device_node *port_node = of_get_parent(node);
> + int size;
> + unsigned int v;
> + u32 data_lanes[ARRAY_SIZE(link->mipi_csi_2.data_lanes)];
> + bool data_lanes_present;
> +
> + memset(link, 0, sizeof(*link));
> +
> + link->local_node = node;
> +
> + /* Doesn't matter, whether the below two calls succeed */
> + of_property_read_u32(port_node, "reg",&link->port);
> + of_property_read_u32(node, "reg",&link->addr);
> +
> + if (!of_property_read_u32(node, "bus-width",&v))
> + link->parallel.bus_width = v;
> +
> + if (!of_property_read_u32(node, "data-shift",&v))
> + link->parallel.data_shift = v;
> +
> + if (!of_property_read_u32(node, "hsync-active",&v))
> + link->mbus_flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
> + V4L2_MBUS_HSYNC_ACTIVE_LOW;
> +
> + if (!of_property_read_u32(node, "vsync-active",&v))
> + link->mbus_flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
> + V4L2_MBUS_VSYNC_ACTIVE_LOW;
> +
> + if (!of_property_read_u32(node, "data-active",&v))
> + link->mbus_flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
> + V4L2_MBUS_DATA_ACTIVE_LOW;
> +
> + if (!of_property_read_u32(node, "pclk-sample",&v))
> + link->mbus_flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
> + V4L2_MBUS_PCLK_SAMPLE_FALLING;
> +
> + if (!of_property_read_u32(node, "field-even-active",&v))
> + link->mbus_flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
> + V4L2_MBUS_FIELD_EVEN_LOW;
> +
> + if (of_get_property(node, "slave-mode",&size))
> + link->mbus_flags |= V4L2_MBUS_SLAVE;
> +
> + /* If any parallel-bus properties have been found, skip serial ones */
> + if (link->parallel.bus_width || link->parallel.data_shift ||
> + link->mbus_flags) {
> + /* Default parallel bus-master */
> + if (!(link->mbus_flags& V4L2_MBUS_SLAVE))
> + link->mbus_flags |= V4L2_MBUS_MASTER;
> + return;
> + }
> +
> + if (!of_property_read_u32(node, "clock-lanes",&v))
> + link->mipi_csi_2.clock_lane = v;
> +
> + if (!of_property_read_u32_array(node, "data-lanes", data_lanes,
> + ARRAY_SIZE(data_lanes))) {
> + int i;
> + for (i = 0; i< ARRAY_SIZE(data_lanes); i++)
> + link->mipi_csi_2.data_lanes[i] = data_lanes[i];
It doesn't look like what we aimed for. The data-lanes array is supposed
to be of variable length, thus I don't think it can be parsed like that.
Or am I missing something ? I think we need more something like below
(based on of_property_read_u32_array(), not tested):
void v4l2_of_parse_mipi_csi2(const struct device_node *node,
struct mipi_csi2 *mipi_csi2)
{
struct property *prop = of_find_property(node, "data-lanes", NULL);
u8 *out_data_lanes = mipi_csi_2->data_lanes;
int num_lanes;
const __be32 *val;
if (!prop)
return;
mipi_csi2->num_lanes = 0;
if (WARN (!prop->value, "Empty data-lanes property\n"))
return;
num_lanes = prop->length / sizeof(u32);
if (WARN_ON(num_lanes > ARRAY_SIZE(mipi_csi_2->data_lanes))
num_lanes = ARRAY_SIZE(mipi_csi_2->data_lanes);
val = prop->value;
while (num_lanes--)
*out_data_lanes++ = be32_to_cpup(val++);
mipi_csi2->num_lanes = num_lanes;
}
v4l2_of_parse_mipi_csi2(node, &link->mipi_csi2);
> + data_lanes_present = true;
> + } else {
> + data_lanes_present = false;
> + }
> +
> + if (of_get_property(node, "clock-noncontinuous",&size))
> + link->mbus_flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
> +
> + if ((link->mipi_csi_2.clock_lane || data_lanes_present)&&
> + !(link->mbus_flags& V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK))
> + /* Default CSI-2: continuous clock */
> + link->mbus_flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
> +}
> +EXPORT_SYMBOL(v4l2_of_parse_link);
> +
...
> diff --git a/include/media/v4l2-of.h b/include/media/v4l2-of.h
> new file mode 100644
> index 0000000..6fafedb
> --- /dev/null
> +++ b/include/media/v4l2-of.h
> @@ -0,0 +1,62 @@
> +/*
> + * V4L2 OF binding parsing library
> + *
> + * Copyright (C) 2012 Renesas Electronics Corp.
> + * Author: Guennadi Liakhovetski<g.liakhovetski@xxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of version 2 of the GNU General Public License as
> + * published by the Free Software Foundation.
> + */
> +#ifndef _V4L2_OF_H
> +#define _V4L2_OF_H
> +
> +#include<linux/list.h>
> +#include<linux/types.h>
> +
> +#include<media/v4l2-mediabus.h>
> +
> +struct device_node;
> +
> +struct v4l2_of_link {
> + unsigned int port;
> + unsigned int addr;
> + struct list_head head;
> + const struct device_node *local_node;
> + const __be32 *remote;
> + unsigned int mbus_flags;
> + union {
> + struct {
> + unsigned char bus_width;
> + unsigned char data_shift;
> + } parallel;
> + struct {
> + unsigned char data_lanes[4];
Some devices are interested only in absolute number of lanes.
I can't see how we could specify the number of data lanes here.
Shouldn't something like 'unsigned char num_data_lanes;' be
added to this structure ?
> + unsigned char clock_lane;
> + } mipi_csi_2;
> + };
> +};
--
Thanks,
Sylwester
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