media: i2c: add Maxim GMSL2/3 serializer and deserializer framework

These drivers are meant to be used as a common framework for Maxim
GMSL2/3 serializers and deserializers.

This framework enables support for the following new features across
all the chips:
 * Full Streams API support
 * .get_frame_desc()
 * .get_mbus_config()
 * I2C ATR
 * automatic GMSL link version negotiation
 * automatic stream id selection
 * automatic VC remapping
 * automatic pixel mode / tunnel mode selection
 * automatic double mode selection / data padding
 * logging of internal state and chip status registers via .log_status()
 * PHY modes
 * serializer pinctrl
 * TPG

Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Tested-by: Martin Hecht <mhecht73@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
This commit is contained in:
Cosmin Tanislav 2026-09-30 01:41:48 +03:00 committed by Sakari Ailus
parent 424e37817b
commit b8749c5a68
7 changed files with 618 additions and 0 deletions

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@ -16120,6 +16120,7 @@ M: Cosmin Tanislav <cosmin.tanislav@analog.com>
L: linux-media@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/media/i2c/maxim,max9296a.yaml
F: drivers/media/i2c/maxim-serdes/
MAXIM MAX11205 DRIVER
M: Ramona Bolboaca <ramona.bolboaca@analog.com>

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@ -1863,6 +1863,8 @@ config VIDEO_MAX96717
To compile this driver as a module, choose M here: the
module will be called max96717.
source "drivers/media/i2c/maxim-serdes/Kconfig"
endmenu
endif # VIDEO_DEV

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@ -76,6 +76,7 @@ obj-$(CONFIG_VIDEO_MAX9271_LIB) += max9271.o
obj-$(CONFIG_VIDEO_MAX9286) += max9286.o
obj-$(CONFIG_VIDEO_MAX96714) += max96714.o
obj-$(CONFIG_VIDEO_MAX96717) += max96717.o
obj-$(CONFIG_VIDEO_MAXIM_SERDES) += maxim-serdes/
obj-$(CONFIG_VIDEO_ML86V7667) += ml86v7667.o
obj-$(CONFIG_VIDEO_MSP3400) += msp3400.o
obj-$(CONFIG_VIDEO_MT9M001) += mt9m001.o

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@ -0,0 +1,17 @@
# SPDX-License-Identifier: GPL-2.0
config VIDEO_MAXIM_SERDES
tristate "Maxim GMSL2/3 Serializer and Deserializer support"
depends on VIDEO_DEV
depends on I2C
select I2C_ATR
select I2C_MUX
select MEDIA_CONTROLLER
select V4L2_FWNODE
select VIDEO_V4L2_SUBDEV_API
help
This driver supports the Maxim GMSL2/3 common Serializer and
Deserializer framework.
To compile this driver as a module, choose M here: the module
will be called max_serdes.

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@ -0,0 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
max-serdes-objs := max_serdes.o
obj-$(CONFIG_VIDEO_MAXIM_SERDES) += max-serdes.o

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@ -0,0 +1,413 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2025 Analog Devices Inc.
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/stringify.h>
#include <media/mipi-csi2.h>
#include <video/videomode.h>
#include <uapi/linux/media-bus-format.h>
#include "max_serdes.h"
const char * const max_serdes_tpg_patterns[] = {
[MAX_SERDES_TPG_PATTERN_GRADIENT] = "Gradient",
[MAX_SERDES_TPG_PATTERN_CHECKERBOARD] = "Checkerboard",
};
static const char * const max_gmsl_versions[] = {
[MAX_SERDES_GMSL_2_3GBPS] = "GMSL2 3Gbps",
[MAX_SERDES_GMSL_2_6GBPS] = "GMSL2 6Gbps",
[MAX_SERDES_GMSL_3_12GBPS] = "GMSL3 12Gbps",
};
const char *max_serdes_gmsl_version_str(enum max_serdes_gmsl_version version)
{
if (version > MAX_SERDES_GMSL_3_12GBPS)
return NULL;
return max_gmsl_versions[version];
}
static const char * const max_gmsl_mode[] = {
[MAX_SERDES_GMSL_PIXEL_MODE] = "pixel",
[MAX_SERDES_GMSL_TUNNEL_MODE] = "tunnel",
};
const char *max_serdes_gmsl_mode_str(enum max_serdes_gmsl_mode mode)
{
if (mode > MAX_SERDES_GMSL_TUNNEL_MODE)
return NULL;
return max_gmsl_mode[mode];
}
static const struct max_serdes_mipi_format max_serdes_mipi_formats[] = {
{ MIPI_CSI2_DT_EMBEDDED_8B, 8 },
{ MIPI_CSI2_DT_YUV422_8B, 16 },
{ MIPI_CSI2_DT_YUV422_10B, 20 },
{ MIPI_CSI2_DT_RGB565, 16 },
{ MIPI_CSI2_DT_RGB666, 18 },
{ MIPI_CSI2_DT_RGB888, 24 },
{ MIPI_CSI2_DT_RAW8, 8 },
{ MIPI_CSI2_DT_RAW10, 10 },
{ MIPI_CSI2_DT_RAW12, 12 },
{ MIPI_CSI2_DT_RAW14, 14 },
{ MIPI_CSI2_DT_RAW16, 16 },
};
const struct max_serdes_mipi_format *max_serdes_mipi_format_by_dt(u8 dt)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(max_serdes_mipi_formats); i++)
if (max_serdes_mipi_formats[i].dt == dt)
return &max_serdes_mipi_formats[i];
return NULL;
}
int max_serdes_get_fd_stream_entry(struct v4l2_subdev *sd, u32 pad, u32 stream,
struct v4l2_mbus_frame_desc_entry *entry)
{
struct v4l2_mbus_frame_desc fd;
unsigned int i;
int ret;
ret = v4l2_subdev_call(sd, pad, get_frame_desc, pad, &fd);
if (ret)
return ret;
if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
return -EOPNOTSUPP;
for (i = 0; i < fd.num_entries; i++) {
if (fd.entry[i].stream == stream) {
*entry = fd.entry[i];
return 0;
}
}
return -ENOENT;
}
int max_serdes_get_fd_bpp(struct v4l2_mbus_frame_desc_entry *entry,
unsigned int *bpp)
{
const struct max_serdes_mipi_format *format;
format = max_serdes_mipi_format_by_dt(entry->bus.csi2.dt);
if (!format)
return -ENOENT;
*bpp = format->bpp;
return 0;
}
int max_serdes_process_bpps(struct device *dev, u32 bpps,
u32 allowed_double_bpps, unsigned int *doubled_bpp)
{
unsigned int min_bpp;
unsigned int max_bpp;
bool doubled = false;
if (!bpps)
return 0;
*doubled_bpp = 0;
/*
* Hardware can double bpps 8, 10, 12, and it can pad bpps < 16
* to another bpp <= 16:
* Hardware can only stream a single constant bpp up to 24.
*
* From these features and limitations, the following rules
* can be deduced:
*
* A bpp of 8 can always be doubled if present.
* A bpp of 10 can be doubled only if there are no other bpps or the
* only other bpp is 20.
* A bpp of 12 can be doubled only if there are no other bpps or the
* only other bpp is 24.
* Bpps <= 16 cannot coexist with bpps > 16.
* Bpps <= 16 need to be padded to the biggest bpp.
*/
min_bpp = __ffs(bpps);
max_bpp = __fls(bpps);
if (min_bpp == 8) {
doubled = true;
} else if (min_bpp == 10 || min_bpp == 12) {
u32 bpp_or_double = BIT(min_bpp) | BIT(min_bpp * 2);
u32 other_bpps = bpps & ~bpp_or_double;
if (!other_bpps)
doubled = true;
}
if (doubled && (allowed_double_bpps & BIT(min_bpp))) {
*doubled_bpp = min_bpp;
bpps &= ~BIT(min_bpp);
bpps |= BIT(min_bpp * 2);
}
min_bpp = __ffs(bpps);
max_bpp = __fls(bpps);
if (max_bpp > 24) {
dev_err(dev, "Cannot stream bpps > 24\n");
return -EINVAL;
}
if (min_bpp <= 16 && max_bpp > 16) {
dev_err(dev, "Cannot stream bpps <= 16 with bpps > 16\n");
return -EINVAL;
}
if (max_bpp > 16 && min_bpp != max_bpp) {
dev_err(dev, "Cannot stream multiple bpps when one is > 16\n");
return -EINVAL;
}
return 0;
}
int max_serdes_xlate_enable_disable_streams(struct max_serdes_source *sources,
u32 source_sink_pad_offset,
const struct v4l2_subdev_state *state,
u32 pad, u64 updated_streams_mask,
u32 sink_pad_start, u32 num_sink_pads,
bool enable)
{
u32 failed_sink_pad;
int ret;
u32 i;
for (i = sink_pad_start; i < sink_pad_start + num_sink_pads; i++) {
u64 matched_streams_mask = updated_streams_mask;
u64 updated_sink_streams_mask;
struct max_serdes_source *source;
updated_sink_streams_mask =
v4l2_subdev_state_xlate_streams(state, pad, i,
&matched_streams_mask);
if (!updated_sink_streams_mask)
continue;
source = &sources[i + source_sink_pad_offset];
if (!source->sd)
continue;
if (enable)
ret = v4l2_subdev_enable_streams(source->sd, source->pad,
updated_sink_streams_mask);
else
ret = v4l2_subdev_disable_streams(source->sd, source->pad,
updated_sink_streams_mask);
if (ret) {
failed_sink_pad = i;
goto err;
}
}
return 0;
err:
for (i = sink_pad_start; i < failed_sink_pad; i++) {
u64 matched_streams_mask = updated_streams_mask;
u64 updated_sink_streams_mask;
struct max_serdes_source *source;
updated_sink_streams_mask =
v4l2_subdev_state_xlate_streams(state, pad, i,
&matched_streams_mask);
if (!updated_sink_streams_mask)
continue;
source = &sources[i + source_sink_pad_offset];
if (!source->sd)
continue;
if (!enable)
v4l2_subdev_enable_streams(source->sd, source->pad,
updated_sink_streams_mask);
else
v4l2_subdev_disable_streams(source->sd, source->pad,
updated_sink_streams_mask);
}
return ret;
}
int max_serdes_get_streams_masks(struct device *dev,
const struct v4l2_subdev_state *state,
u32 pad, u64 updated_streams_mask,
u32 num_pads, u64 *old_streams_masks,
u64 **new_streams_masks, bool enable)
{
u64 *streams_masks;
unsigned int i;
streams_masks = devm_kcalloc(dev, num_pads, sizeof(*streams_masks), GFP_KERNEL);
if (!streams_masks)
return -ENOMEM;
for (i = 0; i < num_pads; i++) {
u64 matched_streams_mask = updated_streams_mask;
u64 updated_sink_streams_mask;
streams_masks[i] = old_streams_masks[i];
updated_sink_streams_mask =
v4l2_subdev_state_xlate_streams(state, pad, i,
&matched_streams_mask);
if (!updated_sink_streams_mask)
continue;
if (enable)
streams_masks[i] |= updated_sink_streams_mask;
else
streams_masks[i] &= ~updated_sink_streams_mask;
}
if (enable)
streams_masks[pad] |= updated_streams_mask;
else
streams_masks[pad] &= ~updated_streams_mask;
*new_streams_masks = streams_masks;
return 0;
}
static const struct videomode max_serdes_tpg_pixel_videomodes[] = {
{
.pixelclock = 25000000,
.hactive = 640,
.hfront_porch = 10,
.hsync_len = 96,
.hback_porch = 40,
.vactive = 480,
.vfront_porch = 2,
.vsync_len = 24,
.vback_porch = 24,
},
{
.pixelclock = 75000000,
.hactive = 1920,
.hfront_porch = 88,
.hsync_len = 44,
.hback_porch = 148,
.vactive = 1080,
.vfront_porch = 4,
.vsync_len = 16,
.vback_porch = 36,
},
{
.pixelclock = 150000000,
.hactive = 1920,
.hfront_porch = 88,
.hsync_len = 44,
.hback_porch = 148,
.vactive = 1080,
.vfront_porch = 4,
.vsync_len = 16,
.vback_porch = 36,
},
};
static void max_serdes_get_vm_timings(const struct videomode *vm,
struct max_serdes_tpg_timings *timings)
{
u32 hact = vm->hactive;
u32 hfp = vm->hfront_porch;
u32 hsync = vm->hsync_len;
u32 hbp = vm->hback_porch;
u32 htot = hact + hfp + hbp + hsync;
u32 vact = vm->vactive;
u32 vfp = vm->vfront_porch;
u32 vsync = vm->vsync_len;
u32 vbp = vm->vback_porch;
u32 vtot = vact + vfp + vbp + vsync;
*timings = (struct max_serdes_tpg_timings) {
.gen_vs = true,
.gen_hs = true,
.gen_de = true,
.vs_inv = true,
.vs_dly = 0,
.vs_high = vsync * htot,
.vs_low = (vact + vfp + vbp) * htot,
.v2h = 0,
.hs_high = hsync,
.hs_low = hact + hfp + hbp,
.hs_cnt = vact + vfp + vbp + vsync,
.v2d = htot * (vsync + vbp) + (hsync + hbp),
.de_high = hact,
.de_low = hfp + hsync + hbp,
.de_cnt = vact,
.clock = vm->pixelclock,
.fps = DIV_ROUND_CLOSEST(vm->pixelclock, vtot * htot),
};
}
int max_serdes_get_tpg_timings(const struct max_serdes_tpg_entry *entry,
struct max_serdes_tpg_timings *timings)
{
u32 fps;
if (!entry)
return 0;
fps = DIV_ROUND_CLOSEST(1 * entry->interval.denominator,
entry->interval.numerator);
for (unsigned int i = 0; i < ARRAY_SIZE(max_serdes_tpg_pixel_videomodes); i++) {
struct max_serdes_tpg_timings vm_timings;
const struct videomode *vm;
vm = &max_serdes_tpg_pixel_videomodes[i];
max_serdes_get_vm_timings(vm, &vm_timings);
if (vm->hactive == entry->width &&
vm->vactive == entry->height &&
vm_timings.fps == fps) {
*timings = vm_timings;
return 0;
}
}
return -EINVAL;
}
EXPORT_SYMBOL_NS_GPL(max_serdes_get_tpg_timings, "MAX_SERDES");
int max_serdes_validate_tpg_routing(struct v4l2_subdev_krouting *routing)
{
const struct v4l2_subdev_route *route;
if (routing->num_routes != 1)
return -EINVAL;
route = &routing->routes[0];
if (!(route->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))
return -EINVAL;
if (route->sink_stream != MAX_SERDES_TPG_STREAM)
return -EINVAL;
return 0;
}
MODULE_DESCRIPTION("Maxim GMSL2 Serializer/Deserializer Driver");
MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>");
MODULE_LICENSE("GPL");

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@ -0,0 +1,181 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2025 Analog Devices Inc.
*/
#ifndef MAX_SERDES_H
#define MAX_SERDES_H
#include <linux/bitfield.h>
#include <linux/types.h>
#include <media/mipi-csi2.h>
#include <media/v4l2-subdev.h>
#define REG_SEQUENCE_2(reg, val) \
{ (reg), ((val) >> 8) & 0xff }, \
{ (reg) + 1, ((val) >> 0) & 0xff }
#define REG_SEQUENCE_3(reg, val) \
{ (reg), ((val) >> 16) & 0xff }, \
{ (reg) + 1, ((val) >> 8) & 0xff }, \
{ (reg) + 2, ((val) >> 0) & 0xff }
#define REG_SEQUENCE_3_LE(reg, val) \
{ (reg), ((val) >> 0) & 0xff }, \
{ (reg) + 1, ((val) >> 8) & 0xff }, \
{ (reg) + 2, ((val) >> 16) & 0xff }
#define MAX_SERDES_PHYS_MAX 4
#define MAX_SERDES_STREAMS_NUM 4
#define MAX_SERDES_VC_ID_NUM 4
#define MAX_SERDES_TPG_STREAM 0
#define MAX_SERDES_GRAD_INCR 4
#define MAX_SERDES_CHECKER_COLOR_A 0x00ccfe
#define MAX_SERDES_CHECKER_COLOR_B 0xa76a00
#define MAX_SERDES_CHECKER_SIZE 60
extern const char * const max_serdes_tpg_patterns[];
enum max_serdes_gmsl_version {
MAX_SERDES_GMSL_MIN,
MAX_SERDES_GMSL_2_3GBPS = MAX_SERDES_GMSL_MIN,
MAX_SERDES_GMSL_2_6GBPS,
MAX_SERDES_GMSL_3_12GBPS,
MAX_SERDES_GMSL_MAX = MAX_SERDES_GMSL_3_12GBPS,
};
enum max_serdes_gmsl_mode {
MAX_SERDES_GMSL_PIXEL_MODE,
MAX_SERDES_GMSL_TUNNEL_MODE,
};
enum max_serdes_tpg_pattern {
MAX_SERDES_TPG_PATTERN_MIN,
MAX_SERDES_TPG_PATTERN_CHECKERBOARD = MAX_SERDES_TPG_PATTERN_MIN,
MAX_SERDES_TPG_PATTERN_GRADIENT,
MAX_SERDES_TPG_PATTERN_MAX = MAX_SERDES_TPG_PATTERN_GRADIENT,
};
struct max_serdes_phys_config {
unsigned int lanes[MAX_SERDES_PHYS_MAX];
unsigned int clock_lane[MAX_SERDES_PHYS_MAX];
};
struct max_serdes_phys_configs {
const struct max_serdes_phys_config *configs;
unsigned int num_configs;
};
struct max_serdes_i2c_xlate {
u8 src;
u8 dst;
bool en;
};
struct max_serdes_mipi_format {
u8 dt;
u8 bpp;
};
struct max_serdes_vc_remap {
u8 src;
u8 dst;
};
struct max_serdes_source {
struct v4l2_subdev *sd;
u16 pad;
struct fwnode_handle *ep_fwnode;
unsigned int index;
};
struct max_serdes_asc {
struct v4l2_async_connection base;
struct max_serdes_source *source;
};
struct max_serdes_tpg_entry {
u32 width;
u32 height;
struct v4l2_fract interval;
u32 code;
u8 dt;
u8 bpp;
};
#define MAX_TPG_ENTRY_640X480P60_RGB888 \
{ 640, 480, { 1, 60 }, MEDIA_BUS_FMT_RGB888_1X24, MIPI_CSI2_DT_RGB888, 24 }
#define MAX_TPG_ENTRY_1920X1080P30_RGB888 \
{ 1920, 1080, { 1, 30 }, MEDIA_BUS_FMT_RGB888_1X24, MIPI_CSI2_DT_RGB888, 24 }
#define MAX_TPG_ENTRY_1920X1080P60_RGB888 \
{ 1920, 1080, { 1, 60 }, MEDIA_BUS_FMT_RGB888_1X24, MIPI_CSI2_DT_RGB888, 24 }
struct max_serdes_tpg_entries {
const struct max_serdes_tpg_entry *entries;
unsigned int num_entries;
};
struct max_serdes_tpg_timings {
bool gen_vs;
bool gen_hs;
bool gen_de;
bool vs_inv;
bool hs_inv;
bool de_inv;
u32 vs_dly;
u32 vs_high;
u32 vs_low;
u32 v2h;
u32 hs_high;
u32 hs_low;
u32 hs_cnt;
u32 v2d;
u32 de_high;
u32 de_low;
u32 de_cnt;
u32 clock;
u32 fps;
};
static inline struct max_serdes_asc *asc_to_max(struct v4l2_async_connection *asc)
{
return container_of(asc, struct max_serdes_asc, base);
}
const char *max_serdes_gmsl_version_str(enum max_serdes_gmsl_version version);
const char *max_serdes_gmsl_mode_str(enum max_serdes_gmsl_mode mode);
const struct max_serdes_mipi_format *max_serdes_mipi_format_by_dt(u8 dt);
int max_serdes_get_fd_stream_entry(struct v4l2_subdev *sd, u32 pad, u32 stream,
struct v4l2_mbus_frame_desc_entry *entry);
int max_serdes_get_fd_bpp(struct v4l2_mbus_frame_desc_entry *entry,
unsigned int *bpp);
int max_serdes_process_bpps(struct device *dev, u32 bpps,
u32 allowed_double_bpps, unsigned int *doubled_bpp);
int max_serdes_xlate_enable_disable_streams(struct max_serdes_source *sources,
u32 source_sink_pad_offset,
const struct v4l2_subdev_state *state,
u32 pad, u64 updated_streams_mask,
u32 sink_pad_start, u32 num_sink_pads,
bool enable);
int max_serdes_get_streams_masks(struct device *dev,
const struct v4l2_subdev_state *state,
u32 pad, u64 updated_streams_mask,
u32 num_pads, u64 *old_streams_masks,
u64 **new_streams_masks, bool enable);
int max_serdes_get_tpg_timings(const struct max_serdes_tpg_entry *entry,
struct max_serdes_tpg_timings *timings);
int max_serdes_validate_tpg_routing(struct v4l2_subdev_krouting *routing);
#endif // MAX_SERDES_H