Hi Sakari,
Thank you for the patch.
On Thursday 06 Apr 2017 16:12:04 Sakari Ailus wrote:
> The fwnode_handle is a more generic way than OF device_node to describe
> firmware nodes. Instead of the OF API, use more generic fwnode API to
> obtain the same information.
I would mention that this is a copy of v4l2-of.c with the OF API replaced with
the fwnode API.
> As the V4L2 fwnode support will be required by a small minority of e.g.
> ACPI based systems (the same might actually go for OF), make this a module
> instead of embedding it in the videodev module.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/Kconfig | 3 +
> drivers/media/v4l2-core/Makefile | 1 +
> drivers/media/v4l2-core/v4l2-fwnode.c | 353 +++++++++++++++++++++++++++++++
> include/media/v4l2-fwnode.h | 104 ++++++++++
> 4 files changed, 461 insertions(+)
> create mode 100644 drivers/media/v4l2-core/v4l2-fwnode.c
> create mode 100644 include/media/v4l2-fwnode.h
>
> diff --git a/drivers/media/v4l2-core/Kconfig
> b/drivers/media/v4l2-core/Kconfig index 6b1b78f..a35c336 100644
> --- a/drivers/media/v4l2-core/Kconfig
> +++ b/drivers/media/v4l2-core/Kconfig
> @@ -55,6 +55,9 @@ config V4L2_FLASH_LED_CLASS
>
> When in doubt, say N.
>
> +config V4L2_FWNODE
> + tristate
> +
> # Used by drivers that need Videobuf modules
> config VIDEOBUF_GEN
> tristate
> diff --git a/drivers/media/v4l2-core/Makefile
> b/drivers/media/v4l2-core/Makefile index 795a535..cf77a63 100644
> --- a/drivers/media/v4l2-core/Makefile
> +++ b/drivers/media/v4l2-core/Makefile
> @@ -13,6 +13,7 @@ endif
> ifeq ($(CONFIG_OF),y)
> videodev-objs += v4l2-of.o
> endif
> +obj-$(CONFIG_V4L2_FWNODE) += v4l2-fwnode.o
> ifeq ($(CONFIG_TRACEPOINTS),y)
> videodev-objs += vb2-trace.o v4l2-trace.o
> endif
> diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c
> b/drivers/media/v4l2-core/v4l2-fwnode.c new file mode 100644
> index 0000000..4f69b11
> --- /dev/null
> +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> @@ -0,0 +1,353 @@
> +/*
> + * V4L2 fwnode binding parsing library
> + *
> + * Copyright (c) 2016 Intel Corporation.
> + * Author: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> + *
> + * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
> + * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> + *
> + * 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/acpi.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/property.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/types.h>
> +
> +#include <media/v4l2-fwnode.h>
> +
> +static int v4l2_fwnode_endpoint_parse_csi_bus(struct fwnode_handle *fwn,
> + struct v4l2_fwnode_endpoint
*vfwn)
> +{
> + struct v4l2_fwnode_bus_mipi_csi2 *bus = &vfwn->bus.mipi_csi2;
> + bool have_clk_lane = false;
> + unsigned int flags = 0, lanes_used = 0;
> + unsigned int i;
> + u32 v;
> + int rval;
I would have used "ret" instead of "rval" ;-)
> + rval = fwnode_property_read_u32_array(fwn, "data-lanes", NULL, 0);
> + if (rval > 0) {
> + u32 array[ARRAY_SIZE(bus->data_lanes)];
> +
> + bus->num_data_lanes =
> + min_t(int, ARRAY_SIZE(bus->data_lanes), rval);
> +
> + fwnode_property_read_u32_array(
> + fwn, "data-lanes", array, bus->num_data_lanes);
Is there anything wrong with the usual way to wrap code ?
fwnode_property_read_u32_array(fwn, "data-lanes", array,
bus->num_data_lanes);
> +
> + for (i = 0; i < bus->num_data_lanes; i++) {
> + if (lanes_used & BIT(array[i]))
> + pr_warn("duplicated lane %u in data-lanes\n",
> + array[i]);
> + lanes_used |= BIT(array[i]);
> +
> + bus->data_lanes[i] = array[i];
> + }
> + }
> +
> + rval = fwnode_property_read_u32_array(fwn, "lane-polarities", NULL,
0);
> + if (rval > 0) {
> + u32 array[ARRAY_SIZE(bus->lane_polarities)];
> +
> + if (rval < 1 + bus->num_data_lanes /* clock + data */) {
> + pr_warn("too few lane-polarities entries (need %u, got
%u)\n",
> + 1 + bus->num_data_lanes, rval);
> + return -EINVAL;
> + }
> +
> + fwnode_property_read_u32_array(
> + fwn, "lane-polarities", array, 1 + bus-
>num_data_lanes);
Ditto with
fwnode_property_read_u32_array(fwn, "lane-polarities", array,
1 + bus->num_data_lanes);
> + for (i = 0; i < 1 + bus->num_data_lanes; i++)
> + bus->lane_polarities[i] = array[i];
> + }
> +
> + if (!fwnode_property_read_u32(fwn, "clock-lanes", &v)) {
> + if (lanes_used & BIT(v))
> + pr_warn("duplicated lane %u in clock-lanes\n", v);
> + lanes_used |= BIT(v);
> +
> + bus->clock_lane = v;
> + have_clk_lane = true;
> + }
> +
> + if (fwnode_property_present(fwn, "clock-noncontinuous"))
> + flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
> + else if (have_clk_lane || bus->num_data_lanes > 0)
> + flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
> +
> + bus->flags = flags;
> + vfwn->bus_type = V4L2_MBUS_CSI2;
> +
> + return 0;
> +}
> +
> +static void v4l2_fwnode_endpoint_parse_parallel_bus(
> + struct fwnode_handle *fwn, struct v4l2_fwnode_endpoint *vfwn)
> +{
> + struct v4l2_fwnode_bus_parallel *bus = &vfwn->bus.parallel;
> + unsigned int flags = 0;
> + u32 v;
> +
> + if (!fwnode_property_read_u32(fwn, "hsync-active", &v))
> + flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
> + V4L2_MBUS_HSYNC_ACTIVE_LOW;
> +
> + if (!fwnode_property_read_u32(fwn, "vsync-active", &v))
> + flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
> + V4L2_MBUS_VSYNC_ACTIVE_LOW;
> +
> + if (!fwnode_property_read_u32(fwn, "field-even-active", &v))
> + flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
> + V4L2_MBUS_FIELD_EVEN_LOW;
> + if (flags)
> + vfwn->bus_type = V4L2_MBUS_PARALLEL;
> + else
> + vfwn->bus_type = V4L2_MBUS_BT656;
> +
> + if (!fwnode_property_read_u32(fwn, "pclk-sample", &v))
> + flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
> + V4L2_MBUS_PCLK_SAMPLE_FALLING;
> +
> + if (!fwnode_property_read_u32(fwn, "data-active", &v))
> + flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
> + V4L2_MBUS_DATA_ACTIVE_LOW;
> +
> + if (fwnode_property_present(fwn, "slave-mode"))
> + flags |= V4L2_MBUS_SLAVE;
> + else
> + flags |= V4L2_MBUS_MASTER;
> +
> + if (!fwnode_property_read_u32(fwn, "bus-width", &v))
> + bus->bus_width = v;
> +
> + if (!fwnode_property_read_u32(fwn, "data-shift", &v))
> + bus->data_shift = v;
> +
> + if (!fwnode_property_read_u32(fwn, "sync-on-green-active", &v))
> + flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
> + V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
> +
> + bus->flags = flags;
> +
> +}
> +
> +/**
> + * v4l2_fwnode_endpoint_parse() - parse all fwnode node properties
> + * @fwn: pointer to fwnode_handle
I would say "the endpoint's fwnode handle", or "pointer to the endpoint's
fwnode handle". Otherwise which fwnode handle should be passed won't be clear.
> + * @vfwn: pointer to the V4L2 fwnode data structure
> + *
> + * 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 that identify the bus as parallel are found 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.
s/@node/@fwn/
By the way, have you tried to compile the documentation ?
> + *
> + * NOTE: This function does not parse properties the size of which is
> + * variable without a low fixed limit. Please use
> + * v4l2_fwnode_endpoint_alloc_parse() in new drivers instead.
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwn,
> + struct v4l2_fwnode_endpoint *vfwn)
Is there a specific reason not to keep the original parameter name "endpoint"
? vfwn seems to stand for v4l2_fwnode, not v4l2_fwnode_endpoint. Same comment
for all other locations in this patch.
> +{
> + int rval;
> +
> + fwnode_graph_parse_endpoint(fwn, &vfwn->base);
> +
> + /* Zero fields from bus_type to until the end */
> + memset(&vfwn->bus_type, 0, sizeof(*vfwn) -
> + offsetof(typeof(*vfwn), bus_type));
> +
> + rval = v4l2_fwnode_endpoint_parse_csi_bus(fwn, vfwn);
> + if (rval)
> + return rval;
> + /*
> + * Parse the parallel video bus properties only if none
> + * of the MIPI CSI-2 specific properties were found.
> + */
> + if (vfwn->bus.mipi_csi2.flags == 0)
> + v4l2_fwnode_endpoint_parse_parallel_bus(fwn, vfwn);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(v4l2_fwnode_endpoint_parse);
According to Mauro in http://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg110809.html you should use EXPORT_SYMBOL_GPL.
> +
> +/*
> + * v4l2_fwnode_endpoint_free() - free the V4L2 fwnode acquired by
> + * v4l2_fwnode_endpoint_alloc_parse()
> + * @fwn - the V4L2 fwnode the resources of which are to be released
Mayeb "the V4L2 fwnode whose resources are to be released" ?
> + *
> + * It is safe to call this function with NULL argument or on an
s/on an/on a/
> + * V4L2 fwnode the parsing of which failed.
"whose parsing failed" ?
> + */
> +void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vfwn)
> +{
> + if (IS_ERR_OR_NULL(vfwn))
> + return;
> +
> + kfree(vfwn->link_frequencies);
> + kfree(vfwn);
> +}
> +EXPORT_SYMBOL(v4l2_fwnode_endpoint_free);
> +
> +/**
> + * v4l2_fwnode_endpoint_alloc_parse() - parse all fwnode node properties
> + * @node: pointer to fwnode_handle
s/@node/@fwn/
Here too, I would say "the endpoint's fwnode handle", or "pointer to the
endpoint's fwnode handle".
> + *
> + * 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 that identify the bus as parallel are found 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.
s/@node/@fwn/
> + *
> + * v4l2_fwnode_endpoint_alloc_parse() has two important differences to
> + * v4l2_fwnode_endpoint_parse():
> + *
> + * 1. It also parses variable size data and
Nitpicking, a valid sentence doesn't end with "and$". You could write
1. It also parses variable size data.
2. The memory it has allocated to store the variable size data must
be freed using v4l2_fwnode_endpoint_free() when no longer needed.
or
1. it also parses variable size data; and
2. the memory it has allocated to store the variable size data must
be freed using v4l2_fwnode_endpoint_free() when no longer needed.
> + *
> + * 2. The memory it has allocated to store the variable size data must
> + * be freed using v4l2_fwnode_endpoint_free() when no longer needed.
> + *
> + * Return: Pointer to v4l2_fwnode_endpoint if successful, on error a
> + * negative error code.
The function returns an error pointer on error.
> + */
> +struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
> + struct fwnode_handle *fwn)
> +{
> + struct v4l2_fwnode_endpoint *vfwn;
> + int rval;
ret ? :-)
> +
> + vfwn = kzalloc(sizeof(*vfwn), GFP_KERNEL);
> + if (!vfwn)
> + return ERR_PTR(-ENOMEM);
> +
> + rval = v4l2_fwnode_endpoint_parse(fwn, vfwn);
> + if (rval < 0)
> + goto out_err;
> +
> + rval = fwnode_property_read_u64_array(fwn, "link-frequencies",
> + NULL, 0);
> +
No need for a blank line.
> + if (rval < 0)
> + goto out_err;
> +
> + vfwn->link_frequencies =
> + kmalloc_array(rval, sizeof(*vfwn->link_frequencies),
> + GFP_KERNEL);
> + if (!vfwn->link_frequencies) {
> + rval = -ENOMEM;
> + goto out_err;
> + }
> +
> + vfwn->nr_of_link_frequencies = rval;
> +
> + rval = fwnode_property_read_u64_array(
> + fwn, "link-frequencies", vfwn->link_frequencies,
> + vfwn->nr_of_link_frequencies);
rval = fwnode_property_read_u64_array(fwn, "link-frequencies",
vfwn->link_frequencies,
vfwn->nr_of_link_frequencies);
> + if (rval < 0)
> + goto out_err;
> +
> + return vfwn;
> +
> +out_err:
> + v4l2_fwnode_endpoint_free(vfwn);
> + return ERR_PTR(rval);
> +}
> +EXPORT_SYMBOL(v4l2_fwnode_endpoint_alloc_parse);
> +
> +/**
> + * v4l2_fwnode_endpoint_parse_link() - parse a link between two endpoints
> + * @node: pointer to the fwnode at the local end of the link
The parameter is called __fwn. I believe you should rename it to fwn,
otherwise the documentation will look weird.
As explained before, you should mention that this is an endpoint fwnode
handle.
> + * @link: pointer to the V4L2 fwnode link data structure
> + *
> + * Fill the link structure with the local and remote nodes and port
> numbers.
> + * The local_node and remote_node fields are set to point to the local and
> + * remote port's parent nodes respectively (the port parent node being the
> + * parent node of the port node if that node isn't a 'ports' node, or the
> + * grand-parent node of the port node otherwise).
> + *
> + * A reference is taken to both the local and remote nodes, the caller
> + * must use v4l2_fwnode_endpoint_put_link() to drop the references
> + * when done with the link.
Just curious, is there a reason to wrap earlier than the 80 columns limit ?
* A reference is taken to both the local and remote nodes, the caller must
use
* v4l2_fwnode_endpoint_put_link() to drop the references when done with the
* link.
would work.
> + * Return: 0 on success, or -ENOLINK if the remote fwnode can't be found.
Here too you should mention remote endpoint.
> + */
> +int v4l2_fwnode_parse_link(struct fwnode_handle *__fwn,
> + struct v4l2_fwnode_link *link)
> +{
> + struct fwnode_handle *fwn;
> + const char *port_prop = is_of_node(__fwn) ? "reg" : "port";
> +
> + memset(link, 0, sizeof(*link));
> +
> + fwn = fwnode_get_parent(__fwn);
> + fwnode_property_read_u32(fwn, port_prop, &link->local_port);
> + fwn = fwnode_get_next_parent(fwn);
> + if (is_of_node(fwn)) {
> + if (of_node_cmp(to_of_node(fwn)->name, "ports") == 0)
> + fwn = fwnode_get_next_parent(fwn);
> + } else {
> + /* The "ports" node is always there in ACPI. */
> + fwn = fwnode_get_next_parent(fwn);
> + }
To avoid duplicating the fwnode_get_next_parent(fwn) call, you could write
if (!is_of_node(fwn) ||
of_node_cmp(to_of_node(fwn)->name, "ports") == 0) {
/* The "ports" node is always there in ACPI. */
fwn = fwnode_get_next_parent(fwn);
}
> + link->local_node = fwn;
> +
> + fwn = fwnode_graph_get_remote_endpoint(fwn);
> + if (!fwn) {
> + fwnode_handle_put(fwn);
> + return -ENOLINK;
> + }
> +
> + fwn = fwnode_get_parent(fwn);
> + fwnode_property_read_u32(fwn, port_prop, &link->remote_port);
> + fwn = fwnode_get_next_parent(fwn);
> + if (is_of_node(fwn)) {
> + if (of_node_cmp(to_of_node(fwn)->name, "ports") == 0)
> + fwn = fwnode_get_next_parent(fwn);
> + } else {
> + /* The "ports" node is always there in ACPI. */
> + fwn = fwnode_get_next_parent(fwn);
> + }
Same comment here.
> + link->remote_node = fwn;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(v4l2_fwnode_parse_link);
> +
> +/**
> + * v4l2_fwnode_put_link() - drop references to nodes in a link
> + * @link: pointer to the V4L2 fwnode link data structure
> + *
> + * Drop references to the local and remote nodes in the link. This
> + * function must be called on every link parsed with
> + * v4l2_fwnode_parse_link().
> + */
> +void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
> +{
> + fwnode_handle_put(link->local_node);
> + fwnode_handle_put(link->remote_node);
> +}
> +EXPORT_SYMBOL(v4l2_fwnode_put_link);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>");
> +MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@xxxxxx>");
> diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
> new file mode 100644
> index 0000000..a675d8a
> --- /dev/null
> +++ b/include/media/v4l2-fwnode.h
> @@ -0,0 +1,104 @@
> +/*
> + * V4L2 fwnode binding parsing library
> + *
> + * Copyright (c) 2016 Intel Corporation.
> + * Author: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> + *
> + * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
> + * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> + *
> + * 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_FWNODE_H
> +#define _V4L2_FWNODE_H
> +
> +#include <linux/list.h>
> +#include <linux/types.h>
> +#include <linux/errno.h>
> +#include <linux/of_graph.h>
Alphabetical order please.
> +#include <media/v4l2-mediabus.h>
> +
> +struct fwnode_handle;
> +
> +/**
> + * struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure
> + * @flags: media bus (V4L2_MBUS_*) flags
> + * @data_lanes: an array of physical data lane indexes
> + * @clock_lane: physical lane index of the clock lane
> + * @num_data_lanes: number of data lanes
> + * @lane_polarities: polarity of the lanes. The order is the same of
> + * the physical lanes.
> + */
> +struct v4l2_fwnode_bus_mipi_csi2 {
> + unsigned int flags;
> + unsigned char data_lanes[4];
> + unsigned char clock_lane;
> + unsigned short num_data_lanes;
> + bool lane_polarities[5];
> +};
> +
> +/**
> + * struct v4l2_fwnode_bus_parallel - parallel data bus data structure
> + * @flags: media bus (V4L2_MBUS_*) flags
> + * @bus_width: bus width in bits
> + * @data_shift: data shift in bits
> + */
> +struct v4l2_fwnode_bus_parallel {
> + unsigned int flags;
> + unsigned char bus_width;
> + unsigned char data_shift;
> +};
> +
> +/**
> + * struct v4l2_fwnode_endpoint - the endpoint data structure
> + * @base: fwnode endpoint of the v4l2_fwnode
> + * @bus_type: bus type
> + * @bus: bus configuration data structure
> + * @link_frequencies: array of supported link frequencies
> + * @nr_of_link_frequencies: number of elements in link_frequenccies array
> + */
> +struct v4l2_fwnode_endpoint {
> + struct fwnode_endpoint base;
> + /*
> + * Fields below this line will be zeroed by
> + * v4l2_fwnode_parse_endpoint()
> + */
> + enum v4l2_mbus_type bus_type;
> + union {
> + struct v4l2_fwnode_bus_parallel parallel;
> + struct v4l2_fwnode_bus_mipi_csi2 mipi_csi2;
> + } bus;
> + u64 *link_frequencies;
> + unsigned int nr_of_link_frequencies;
> +};
> +
> +/**
> + * struct v4l2_fwnode_link - a link between two endpoints
> + * @local_node: pointer to device_node of this endpoint
> + * @local_port: identifier of the port this endpoint belongs to
> + * @remote_node: pointer to device_node of the remote endpoint
> + * @remote_port: identifier of the port the remote endpoint belongs to
> + */
> +struct v4l2_fwnode_link {
> + struct fwnode_handle *local_node;
> + unsigned int local_port;
> + struct fwnode_handle *remote_node;
> + unsigned int remote_port;
> +};
> +
> +int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwn,
> + struct v4l2_fwnode_endpoint *vfwn);
> +struct v4l2_fwnode_endpoint *v4l2_fwnode_endpoint_alloc_parse(
> + struct fwnode_handle *fwn);
> +void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vfwn);
> +int v4l2_fwnode_parse_link(struct fwnode_handle *fwn,
> + struct v4l2_fwnode_link *link);
> +void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
> +
> +#endif /* _V4L2_FWNODE_H */
--
Regards,
Laurent Pinchart
