The MAX9286 is a 4-channel GMSL deserializer with coax or STP input and
CSI-2 output. The device supports multicamera streaming applications,
and features the ability to synchronise the attached cameras.
CSI-2 output can be configured with 1 to 4 lanes, and a control channel
is supported over I2C, which implements an I2C mux to facilitate
communications with connected cameras across the reverse control
channel.
Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
--
v2:
- Fix MAINTAINERS entry
This posting is released with the following modifications to work
without Sakari's VC developments:
- max9286_g_mbus_config() re-instated
- max9286_get_frame_desc() is not bus/csi aware
- max9286_{get,set}_routing() removed
v3:
- Initialise notifier with v4l2_async_notifier_init
- Update for new mbus csi2 format V4L2_MBUS_CSI2_DPHY
v4: - Re-introduce required code to function with the VC series.
- Implement max9286_get_routing, max9286_set_routing
- Remove max9286_g_mbus_config
v5: (internal release)
- Fix printk formatting for hex value
- max9286->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE (add |)
- MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER -> MEDIA_ENT_F_VID_IF_BRIDGE
- Remove 'device is bound' workaround
v6:
- v4l2_subdev_krouting instead of v4l2_subdev_routing separated
to allow integration without the VC/V4L2-Mux series.
- convert sd_to_max9286 to inline function
- rename max9286_device to max9286_priv
- Cleanup the v4l2_async_notifier
- Extend MODULE_AUTHOR
- Replace of_graph_get_endpoint_by_regs with fwnode_graph_get_endpoint_by_id
- Pass default bus type when parsing fwnode endpoint (Manivannan Sadhasivam)
- Use new YAML file reference in MAINTAINERS
- Parse new i2c-mux node in max9286_get_i2c_by_id
(This could/should be refactored to parse these separately first)
- Spelling and calculation fixes in the FSYNC_LOCKED check comments
- Identify each enabled i2c-mux channel in a single pass
- max9286: Improve mux-state readbility [v2]
- Fix frame sync lock durations
- Add comment to describe /why/ we must open the mux in s_stream
- use -EXDEV as return code for failed link synchronisation.
- Fix reference counting of the dt nodeS
- Convert to probe_new for I2C
- Remove redundant max9286_i2c_mux_state
- Provide optional enable-gpio (max9286-pwdn)
v7:
[Kieran]
- Ensure powerdown lines are optional
- Add a 4ms power-up delay
- Add max9286_check_config_link() to core
- Add GPIO chip controller for GPIO0OUT and GPIO1OUT
- Fix GPIO registration
- max9286: Split out async registration
(fixes regulator -EPROBE_DEFERs failures)
- Collect all V4L2 registrations
- balance v4l2_async refcnting
- Rename max9286_v4l2_async_ => max9286_v4l2_notifier_
[Jacopo]
- Remove redundanct MAXIM_I2C_SPEED macros
- Move notifiers operations
- Add delay after reverse channel reconfiguration
- Move link setup to completion
- Fix up max9286_check_config_link() implementation
- Remove redundant dual configuration of reverse channel
MAINTAINERS | 10 +
drivers/media/i2c/Kconfig | 11 +
drivers/media/i2c/Makefile | 1 +
drivers/media/i2c/max9286.c | 1278 +++++++++++++++++++++++++++++++++++
4 files changed, 1300 insertions(+)
create mode 100644 drivers/media/i2c/max9286.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 983d3c97edd1..148706353d25 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10033,6 +10033,16 @@ F: Documentation/devicetree/bindings/hwmon/max6697.txt
F: drivers/hwmon/max6697.c
F: include/linux/platform_data/max6697.h
+MAX9286 QUAD GMSL DESERIALIZER DRIVER
+M: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
+M: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
+M: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
+M: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
+L: linux-media@xxxxxxxxxxxxxxx
+S: Maintained
+F: Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
+F: drivers/media/i2c/max9286.c
+
MAX9860 MONO AUDIO VOICE CODEC DRIVER
M: Peter Rosin <peda@xxxxxxxxxx>
L: alsa-devel@xxxxxxxxxxxxxxxx (moderated for non-subscribers)
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index c68e002d26ea..32a4deb90617 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -442,6 +442,17 @@ config VIDEO_VPX3220
To compile this driver as a module, choose M here: the
module will be called vpx3220.
+config VIDEO_MAX9286
+ tristate "Maxim MAX9286 GMSL deserializer support"
+ depends on I2C && I2C_MUX
+ depends on VIDEO_V4L2_SUBDEV_API && MEDIA_CONTROLLER
+ select V4L2_FWNODE
+ help
+ This driver supports the Maxim MAX9286 GMSL deserializer.
+
+ To compile this driver as a module, choose M here: the
+ module will be called max9286.
+
comment "Video and audio decoders"
config VIDEO_SAA717X
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index c147bb9d28db..8896cf8bfc4f 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -117,5 +117,6 @@ obj-$(CONFIG_VIDEO_IMX290) += imx290.o
obj-$(CONFIG_VIDEO_IMX319) += imx319.o
obj-$(CONFIG_VIDEO_IMX355) += imx355.o
obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
+obj-$(CONFIG_VIDEO_MAX9286) += max9286.o
obj-$(CONFIG_SDR_MAX2175) += max2175.o
diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
new file mode 100644
index 000000000000..a20829297ef6
--- /dev/null
+++ b/drivers/media/i2c/max9286.c
@@ -0,0 +1,1278 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Maxim MAX9286 GMSL Deserializer Driver
+ *
+ * Copyright (C) 2017-2019 Jacopo Mondi
+ * Copyright (C) 2017-2019 Kieran Bingham
+ * Copyright (C) 2017-2019 Laurent Pinchart
+ * Copyright (C) 2017-2019 Niklas Söderlund
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ * Copyright (C) 2015 Cogent Embedded, Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/fwnode.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
+#include <media/v4l2-subdev.h>
+
+/* Register 0x00 */
+#define MAX9286_MSTLINKSEL_AUTO (7 << 5)
+#define MAX9286_MSTLINKSEL(n) ((n) << 5)
+#define MAX9286_EN_VS_GEN BIT(4)
+#define MAX9286_LINKEN(n) (1 << (n))
+/* Register 0x01 */
+#define MAX9286_FSYNCMODE_ECU (3 << 6)
+#define MAX9286_FSYNCMODE_EXT (2 << 6)
+#define MAX9286_FSYNCMODE_INT_OUT (1 << 6)
+#define MAX9286_FSYNCMODE_INT_HIZ (0 << 6)
+#define MAX9286_GPIEN BIT(5)
+#define MAX9286_ENLMO_RSTFSYNC BIT(2)
+#define MAX9286_FSYNCMETH_AUTO (2 << 0)
+#define MAX9286_FSYNCMETH_SEMI_AUTO (1 << 0)
+#define MAX9286_FSYNCMETH_MANUAL (0 << 0)
+#define MAX9286_REG_FSYNC_PERIOD_L 0x06
+#define MAX9286_REG_FSYNC_PERIOD_M 0x07
+#define MAX9286_REG_FSYNC_PERIOD_H 0x08
+/* Register 0x0a */
+#define MAX9286_FWDCCEN(n) (1 << ((n) + 4))
+#define MAX9286_REVCCEN(n) (1 << (n))
+/* Register 0x0c */
+#define MAX9286_HVEN BIT(7)
+#define MAX9286_EDC_6BIT_HAMMING (2 << 5)
+#define MAX9286_EDC_6BIT_CRC (1 << 5)
+#define MAX9286_EDC_1BIT_PARITY (0 << 5)
+#define MAX9286_DESEL BIT(4)
+#define MAX9286_INVVS BIT(3)
+#define MAX9286_INVHS BIT(2)
+#define MAX9286_HVSRC_D0 (2 << 0)
+#define MAX9286_HVSRC_D14 (1 << 0)
+#define MAX9286_HVSRC_D18 (0 << 0)
+/* Register 0x0f */
+#define MAX9286_0X0F_RESERVED BIT(3)
+/* Register 0x12 */
+#define MAX9286_CSILANECNT(n) (((n) - 1) << 6)
+#define MAX9286_CSIDBL BIT(5)
+#define MAX9286_DBL BIT(4)
+#define MAX9286_DATATYPE_USER_8BIT (11 << 0)
+#define MAX9286_DATATYPE_USER_YUV_12BIT (10 << 0)
+#define MAX9286_DATATYPE_USER_24BIT (9 << 0)
+#define MAX9286_DATATYPE_RAW14 (8 << 0)
+#define MAX9286_DATATYPE_RAW11 (7 << 0)
+#define MAX9286_DATATYPE_RAW10 (6 << 0)
+#define MAX9286_DATATYPE_RAW8 (5 << 0)
+#define MAX9286_DATATYPE_YUV422_10BIT (4 << 0)
+#define MAX9286_DATATYPE_YUV422_8BIT (3 << 0)
+#define MAX9286_DATATYPE_RGB555 (2 << 0)
+#define MAX9286_DATATYPE_RGB565 (1 << 0)
+#define MAX9286_DATATYPE_RGB888 (0 << 0)
+/* Register 0x15 */
+#define MAX9286_VC(n) ((n) << 5)
+#define MAX9286_VCTYPE BIT(4)
+#define MAX9286_CSIOUTEN BIT(3)
+#define MAX9286_0X15_RESV (3 << 0)
+/* Register 0x1b */
+#define MAX9286_SWITCHIN(n) (1 << ((n) + 4))
+#define MAX9286_ENEQ(n) (1 << (n))
+/* Register 0x27 */
+#define MAX9286_LOCKED BIT(7)
+/* Register 0x31 */
+#define MAX9286_FSYNC_LOCKED BIT(6)
+/* Register 0x34 */
+#define MAX9286_I2CLOCACK BIT(7)
+#define MAX9286_I2CSLVSH_1046NS_469NS (3 << 5)
+#define MAX9286_I2CSLVSH_938NS_352NS (2 << 5)
+#define MAX9286_I2CSLVSH_469NS_234NS (1 << 5)
+#define MAX9286_I2CSLVSH_352NS_117NS (0 << 5)
+#define MAX9286_I2CMSTBT_837KBPS (7 << 2)
+#define MAX9286_I2CMSTBT_533KBPS (6 << 2)
+#define MAX9286_I2CMSTBT_339KBPS (5 << 2)
+#define MAX9286_I2CMSTBT_173KBPS (4 << 2)
+#define MAX9286_I2CMSTBT_105KBPS (3 << 2)
+#define MAX9286_I2CMSTBT_84KBPS (2 << 2)
+#define MAX9286_I2CMSTBT_28KBPS (1 << 2)
+#define MAX9286_I2CMSTBT_8KBPS (0 << 2)
+#define MAX9286_I2CSLVTO_NONE (3 << 0)
+#define MAX9286_I2CSLVTO_1024US (2 << 0)
+#define MAX9286_I2CSLVTO_256US (1 << 0)
+#define MAX9286_I2CSLVTO_64US (0 << 0)
+/* Register 0x3b */
+#define MAX9286_REV_TRF(n) ((n) << 4)
+#define MAX9286_REV_AMP(n) ((((n) - 30) / 10) << 1) /* in mV */
+#define MAX9286_REV_AMP_X BIT(0)
+/* Register 0x3f */
+#define MAX9286_EN_REV_CFG BIT(6)
+#define MAX9286_REV_FLEN(n) ((n) - 20)
+/* Register 0x49 */
+#define MAX9286_VIDEO_DETECT_MASK 0x0f
+/* Register 0x69 */
+#define MAX9286_LFLTBMONMASKED BIT(7)
+#define MAX9286_LOCKMONMASKED BIT(6)
+#define MAX9286_AUTOCOMBACKEN BIT(5)
+#define MAX9286_AUTOMASKEN BIT(4)
+#define MAX9286_MASKLINK(n) ((n) << 0)
+
+#define MAX9286_NUM_GMSL 4
+#define MAX9286_N_SINKS 4
+#define MAX9286_N_PADS 5
+#define MAX9286_SRC_PAD 4
+
+struct max9286_source {
+ struct v4l2_async_subdev asd;
+ struct v4l2_subdev *sd;
+ struct fwnode_handle *fwnode;
+};
+
+#define asd_to_max9286_source(_asd) \
+ container_of(_asd, struct max9286_source, asd)
+
+struct max9286_priv {
+ struct i2c_client *client;
+ struct gpio_desc *gpiod_pwdn;
+ struct v4l2_subdev sd;
+ struct media_pad pads[MAX9286_N_PADS];
+ struct regulator *regulator;
+ bool poc_enabled;
+
+ struct gpio_chip gpio;
+ u8 gpio_state;
+
+ struct i2c_mux_core *mux;
+ unsigned int mux_channel;
+ bool mux_open;
+
+ struct v4l2_ctrl_handler ctrls;
+
+ struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
+
+ unsigned int nsources;
+ unsigned int source_mask;
+ unsigned int route_mask;
+ unsigned int bound_sources;
+ unsigned int csi2_data_lanes;
+ struct max9286_source sources[MAX9286_NUM_GMSL];
+ struct v4l2_async_notifier notifier;
+};
+
+static struct max9286_source *next_source(struct max9286_priv *priv,
+ struct max9286_source *source)
+{
+ if (!source)
+ source = &priv->sources[0];
+ else
+ source++;
+
+ for (; source < &priv->sources[MAX9286_NUM_GMSL]; source++) {
+ if (source->fwnode)
+ return source;
+ }
+
+ return NULL;
+}
+
+#define for_each_source(priv, source) \
+ for ((source) = NULL; ((source) = next_source((priv), (source))); )
+
+#define to_index(priv, source) ((source) - &(priv)->sources[0])
+
+static inline struct max9286_priv *sd_to_max9286(struct v4l2_subdev *sd)
+{
+ return container_of(sd, struct max9286_priv, sd);
+}
+
+/* -----------------------------------------------------------------------------
+ * I2C IO
+ */
+
+static int max9286_read(struct max9286_priv *priv, u8 reg)
+{
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(priv->client, reg);
+ if (ret < 0)
+ dev_err(&priv->client->dev,
+ "%s: register 0x%02x read failed (%d)\n",
+ __func__, reg, ret);
+
+ return ret;
+}
+
+static int max9286_write(struct max9286_priv *priv, u8 reg, u8 val)
+{
+ int ret;
+
+ ret = i2c_smbus_write_byte_data(priv->client, reg, val);
+ if (ret < 0)
+ dev_err(&priv->client->dev,
+ "%s: register 0x%02x write failed (%d)\n",
+ __func__, reg, ret);
+
+ return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * I2C Multiplexer
+ */
+
+static void max9286_i2c_mux_configure(struct max9286_priv *priv, u8 conf)
+{
+ max9286_write(priv, 0x0a, conf);
+
+ /*
+ * We must sleep after any change to the forward or reverse channel
+ * configuration.
+ */
+ usleep_range(3000, 5000);
+}
+
+static void max9286_i2c_mux_open(struct max9286_priv *priv)
+{
+ /* Open all channels on the MAX9286 */
+ max9286_i2c_mux_configure(priv, 0xff);
+
+ priv->mux_open = true;
+}
+
+static void max9286_i2c_mux_close(struct max9286_priv *priv)
+{
+ /*
+ * Ensure that both the forward and reverse channel are disabled on the
+ * mux, and that the channel ID is invalidated to ensure we reconfigure
+ * on the next max9286_i2c_mux_select() call.
+ */
+ max9286_i2c_mux_configure(priv, 0x00);
+
+ priv->mux_open = false;
+ priv->mux_channel = -1;
+}
+
+static int max9286_i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct max9286_priv *priv = i2c_mux_priv(muxc);
+
+ /* Channel select is disabled when configured in the opened state. */
+ if (priv->mux_open)
+ return 0;
+
+ if (priv->mux_channel == chan)
+ return 0;
+
+ priv->mux_channel = chan;
+
+ max9286_i2c_mux_configure(priv,
+ MAX9286_FWDCCEN(chan) |
+ MAX9286_REVCCEN(chan));
+
+ return 0;
+}
+
+static int max9286_i2c_mux_init(struct max9286_priv *priv)
+{
+ struct max9286_source *source;
+ int ret;
+
+ if (!i2c_check_functionality(priv->client->adapter,
+ I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
+ return -ENODEV;
+
+ priv->mux = i2c_mux_alloc(priv->client->adapter, &priv->client->dev,
+ priv->nsources, 0, I2C_MUX_LOCKED,
+ max9286_i2c_mux_select, NULL);
+ if (!priv->mux)
+ return -ENOMEM;
+
+ priv->mux->priv = priv;
+
+ for_each_source(priv, source) {
+ unsigned int index = to_index(priv, source);
+
+ ret = i2c_mux_add_adapter(priv->mux, 0, index, 0);
+ if (ret < 0)
+ goto error;
+ }
+
+ return 0;
+
+error:
+ i2c_mux_del_adapters(priv->mux);
+ return ret;
+}
+
+static void max9286_configure_i2c(struct max9286_priv *priv, bool localack)
+{
+ u8 config = MAX9286_I2CSLVSH_469NS_234NS | MAX9286_I2CSLVTO_1024US |
+ MAX9286_I2CMSTBT_105KBPS;
+
+ if (localack)
+ config |= MAX9286_I2CLOCACK;
+
+ max9286_write(priv, 0x34, config);
+ usleep_range(3000, 5000);
+}
+
+/*
+ * max9286_check_video_links() - Make sure video links are detected and locked
+ *
+ * Performs safety checks on video link status. Make sure they are detected
+ * and all enabled links are locked.
+ *
+ * Returns 0 for success, -EIO for errors.
+ */
+static int max9286_check_video_links(struct max9286_priv *priv)
+{
+ unsigned int i;
+ int ret;
+
+ /*
+ * Make sure valid video links are detected.
+ * The delay is not characterized in de-serializer manual, wait up
+ * to 5 ms.
+ */
+ for (i = 0; i < 10; i++) {
+ ret = max9286_read(priv, 0x49);
+ if (ret < 0)
+ return -EIO;
+
+ if ((ret & MAX9286_VIDEO_DETECT_MASK) == priv->source_mask)
+ break;
+
+ usleep_range(350, 500);
+ }
+
+ if (i == 10) {
+ dev_err(&priv->client->dev,
+ "Unable to detect video links: 0x%02x\n", ret);
+ return -EIO;
+ }
+
+ /* Make sure all enabled links are locked (4ms max). */
+ for (i = 0; i < 10; i++) {
+ ret = max9286_read(priv, 0x27);
+ if (ret < 0)
+ return -EIO;
+
+ if (ret & MAX9286_LOCKED)
+ break;
+
+ usleep_range(350, 450);
+ }
+
+ if (i == 10) {
+ dev_err(&priv->client->dev, "Not all enabled links locked\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/*
+ * max9286_check_config_link() - Detect and wait for configuration links
+ *
+ * Determine if the configuration channel is up and settled for a link.
+ *
+ * Returns 0 for success, -EIO for errors.
+ */
+static int max9286_check_config_link(struct max9286_priv *priv,
+ unsigned int source_mask)
+{
+ unsigned int conflink_mask = (source_mask & 0x0f) << 4;
+ unsigned int i;
+ int ret;
+
+ /*
+ * Make sure requested configuration links are detected.
+ * The delay is not characterized in the chip manual: wait up
+ * to 5 milliseconds.
+ */
+ for (i = 0; i < 10; i++) {
+ ret = max9286_read(priv, 0x49) & 0xf0;
+ if (ret < 0)
+ return -EIO;
+
+ if (ret == conflink_mask)
+ break;
+
+ usleep_range(350, 500);
+ }
+
+ if (ret != conflink_mask) {
+ dev_err(&priv->client->dev,
+ "Unable to detect configuration links: 0x%02x expected 0x%02x\n",
+ ret, conflink_mask);
+ return -EIO;
+ }
+
+ dev_info(&priv->client->dev,
+ "Successfully detected configuration links after %u loops: 0x%02x\n",
+ i, conflink_mask);
+
+ return 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 Subdev
+ */
+
+static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
+ struct v4l2_subdev *subdev,
+ struct v4l2_async_subdev *asd)
+{
+ struct max9286_priv *priv = sd_to_max9286(notifier->sd);
+ struct max9286_source *source = asd_to_max9286_source(asd);
+ unsigned int index = to_index(priv, source);
+ unsigned int src_pad;
+ int ret;
+
+ ret = media_entity_get_fwnode_pad(&subdev->entity,
+ source->fwnode,
+ MEDIA_PAD_FL_SOURCE);
+ if (ret < 0) {
+ dev_err(&priv->client->dev,
+ "Failed to find pad for %s\n", subdev->name);
+ return ret;
+ }
+
+ priv->bound_sources |= BIT(index);
+ source->sd = subdev;
+ src_pad = ret;
+
+ ret = media_create_pad_link(&source->sd->entity, src_pad,
+ &priv->sd.entity, index,
+ MEDIA_LNK_FL_ENABLED |
+ MEDIA_LNK_FL_IMMUTABLE);
+ if (ret) {
+ dev_err(&priv->client->dev,
+ "Unable to link %s:%u -> %s:%u\n",
+ source->sd->name, src_pad, priv->sd.name, index);
+ return ret;
+ }
+
+ dev_dbg(&priv->client->dev, "Bound %s pad: %u on index %u\n",
+ subdev->name, src_pad, index);
+
+ /*
+ * We can only register v4l2_async_notifiers which do not provide a
+ * means to register a complete callback. bound_sources allows us to
+ * identify when all remove serializers have completed their probe.
+ */
+ if (priv->bound_sources != priv->source_mask)
+ return 0;
+
+ /*
+ * All enabled sources have probed and enabled their reverse control
+ * channels:
+ *
+ * - Verify all configuration links are properly detected
+ * - Disable auto-ack as communication on the control channel are now
+ * stable.
+ */
+ max9286_check_config_link(priv, priv->source_mask);
+
+ /*
+ * Re-configure I2C with local acknowledge disabled after cameras have
+ * probed.
+ */
+ max9286_configure_i2c(priv, false);
+
+ return 0;
+}
+
+static void max9286_notify_unbind(struct v4l2_async_notifier *notifier,
+ struct v4l2_subdev *subdev,
+ struct v4l2_async_subdev *asd)
+{
+ struct max9286_source *source = asd_to_max9286_source(asd);
+
+ source->sd = NULL;
+}
+
+static const struct v4l2_async_notifier_operations max9286_notify_ops = {
+ .bound = max9286_notify_bound,
+ .unbind = max9286_notify_unbind,
+};
+
+static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
+{
+ struct device *dev = &priv->client->dev;
+ struct max9286_source *source = NULL;
+ int ret;
+
+ if (!priv->nsources)
+ return 0;
+
+ v4l2_async_notifier_init(&priv->notifier);
+
+ for_each_source(priv, source) {
+ unsigned int i = to_index(priv, source);
+
+ source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
+ source->asd.match.fwnode = source->fwnode;
+
+ ret = v4l2_async_notifier_add_subdev(&priv->notifier,
+ &source->asd);
+ if (ret) {
+ dev_err(dev, "Failed to add subdev for source %d", i);
+ v4l2_async_notifier_cleanup(&priv->notifier);
+ return ret;
+ }
+
+ /*
+ * Balance the reference counting handled through
+ * v4l2_async_notifier_cleanup()
+ */
+ fwnode_handle_get(source->fwnode);
+ }
+
+ priv->notifier.ops = &max9286_notify_ops;
+
+ ret = v4l2_async_subdev_notifier_register(&priv->sd, &priv->notifier);
+ if (ret) {
+ dev_err(dev, "Failed to register subdev_notifier");
+ v4l2_async_notifier_cleanup(&priv->notifier);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void max9286_v4l2_notifier_unregister(struct max9286_priv *priv)
+{
+ if (!priv->nsources)
+ return;
+
+ v4l2_async_notifier_unregister(&priv->notifier);
+ v4l2_async_notifier_cleanup(&priv->notifier);
+}
+
+static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
+{
+ struct max9286_priv *priv = sd_to_max9286(sd);
+ struct max9286_source *source;
+ unsigned int i;
+ bool sync = false;
+ int ret;
+
+ if (enable) {
+ /*
+ * The frame sync between cameras is transmitted across the
+ * reverse channel as GPIO. We must open all channels while
+ * streaming to allow this synchronisation signal to be shared.
+ */
+ max9286_i2c_mux_open(priv);
+
+ /* Start all cameras. */
+ for_each_source(priv, source) {
+ ret = v4l2_subdev_call(source->sd, video, s_stream, 1);
+ if (ret)
+ return ret;
+ }
+
+ ret = max9286_check_video_links(priv);
+ if (ret)
+ return ret;
+
+ /*
+ * Wait until frame synchronization is locked.
+ *
+ * Manual says frame sync locking should take ~6 VTS.
+ * From practical experience at least 8 are required. Give
+ * 12 complete frames time (~400ms at 30 fps) to achieve frame
+ * locking before returning error.
+ */
+ for (i = 0; i < 40; i++) {
+ if (max9286_read(priv, 0x31) & MAX9286_FSYNC_LOCKED) {
+ sync = true;
+ break;
+ }
+ usleep_range(9000, 11000);
+ }
+
+ if (!sync) {
+ dev_err(&priv->client->dev,
+ "Failed to get frame synchronization\n");
+ return -EXDEV; /* Invalid cross-device link */
+ }
+
+ /*
+ * Enable CSI output, VC set according to link number.
+ * Bit 7 must be set (chip manual says it's 0 and reserved).
+ */
+ max9286_write(priv, 0x15, 0x80 | MAX9286_VCTYPE |
+ MAX9286_CSIOUTEN | MAX9286_0X15_RESV);
+ } else {
+ max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
+
+ /* Stop all cameras. */
+ for_each_source(priv, source)
+ v4l2_subdev_call(source->sd, video, s_stream, 0);
+
+ max9286_i2c_mux_close(priv);
+ }
+
+ return 0;
+}
+
+static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_mbus_code_enum *code)
+{
+ if (code->pad || code->index > 0)
+ return -EINVAL;
+
+ code->code = MEDIA_BUS_FMT_UYVY8_2X8;
+
+ return 0;
+}
+
+static struct v4l2_mbus_framefmt *
+max9286_get_pad_format(struct max9286_priv *priv,
+ struct v4l2_subdev_pad_config *cfg,
+ unsigned int pad, u32 which)
+{
+ switch (which) {
+ case V4L2_SUBDEV_FORMAT_TRY:
+ return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
+ case V4L2_SUBDEV_FORMAT_ACTIVE:
+ return &priv->fmt[pad];
+ default:
+ return NULL;
+ }
+}
+
+static int max9286_set_fmt(struct v4l2_subdev *sd,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *format)
+{
+ struct max9286_priv *priv = sd_to_max9286(sd);
+ struct v4l2_mbus_framefmt *cfg_fmt;
+
+ if (format->pad >= MAX9286_SRC_PAD)
+ return -EINVAL;
+
+ /* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
+ switch (format->format.code) {
+ case MEDIA_BUS_FMT_UYVY8_2X8:
+ case MEDIA_BUS_FMT_VYUY8_2X8:
+ case MEDIA_BUS_FMT_YUYV8_2X8:
+ case MEDIA_BUS_FMT_YVYU8_2X8:
+ break;
+ default:
+ format->format.code = MEDIA_BUS_FMT_YUYV8_2X8;
+ break;
+ }
+
+ cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
+ if (!cfg_fmt)
+ return -EINVAL;
+
+ *cfg_fmt = format->format;
+
+ return 0;
+}
+
+static int max9286_get_fmt(struct v4l2_subdev *sd,
+ struct v4l2_subdev_pad_config *cfg,
+ struct v4l2_subdev_format *format)
+{
+ struct max9286_priv *priv = sd_to_max9286(sd);
+ struct v4l2_mbus_framefmt *cfg_fmt;
+
+ if (format->pad >= MAX9286_SRC_PAD)
+ return -EINVAL;
+
+ cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
+ if (!cfg_fmt)
+ return -EINVAL;
+
+ format->format = *cfg_fmt;
+
+ return 0;
+}
+
+static const struct v4l2_subdev_video_ops max9286_video_ops = {
+ .s_stream = max9286_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
+ .enum_mbus_code = max9286_enum_mbus_code,
+ .get_fmt = max9286_get_fmt,
+ .set_fmt = max9286_set_fmt,
+};
+
+static const struct v4l2_subdev_ops max9286_subdev_ops = {
+ .video = &max9286_video_ops,
+ .pad = &max9286_pad_ops,
+};
+
+static void max9286_init_format(struct v4l2_mbus_framefmt *fmt)
+{
+ fmt->width = 1280;
+ fmt->height = 800;
+ fmt->code = MEDIA_BUS_FMT_UYVY8_2X8;
+ fmt->colorspace = V4L2_COLORSPACE_SRGB;
+ fmt->field = V4L2_FIELD_NONE;
+ fmt->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+ fmt->quantization = V4L2_QUANTIZATION_DEFAULT;
+ fmt->xfer_func = V4L2_XFER_FUNC_DEFAULT;
+}
+
+static int max9286_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
+{
+ struct v4l2_mbus_framefmt *format;
+ unsigned int i;
+
+ for (i = 0; i < MAX9286_N_SINKS; i++) {
+ format = v4l2_subdev_get_try_format(subdev, fh->pad, i);
+ max9286_init_format(format);
+ }
+
+ return 0;
+}
+
+static const struct v4l2_subdev_internal_ops max9286_subdev_internal_ops = {
+ .open = max9286_open,
+};
+
+static int max9286_v4l2_register(struct max9286_priv *priv)
+{
+ struct device *dev = &priv->client->dev;
+ struct fwnode_handle *ep;
+ int ret;
+ int i;
+
+ /* Register v4l2 async notifiers for connected Camera subdevices */
+ ret = max9286_v4l2_notifier_register(priv);
+ if (ret) {
+ dev_err(dev, "Unable to register V4L2 async notifiers\n");
+ return ret;
+ }
+
+ /* Configure V4L2 for the MAX9286 itself */
+
+ v4l2_i2c_subdev_init(&priv->sd, priv->client, &max9286_subdev_ops);
+ priv->sd.internal_ops = &max9286_subdev_internal_ops;
+ priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+ v4l2_ctrl_handler_init(&priv->ctrls, 1);
+ /*
+ * FIXME: Compute the real pixel rate. The 50 MP/s value comes from the
+ * hardcoded frequency in the BSP CSI-2 receiver driver.
+ */
+ v4l2_ctrl_new_std(&priv->ctrls, NULL, V4L2_CID_PIXEL_RATE,
+ 50000000, 50000000, 1, 50000000);
+ priv->sd.ctrl_handler = &priv->ctrls;
+ ret = priv->ctrls.error;
+ if (ret)
+ goto err_async;
+
+ priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
+
+ priv->pads[MAX9286_SRC_PAD].flags = MEDIA_PAD_FL_SOURCE;
+ for (i = 0; i < MAX9286_SRC_PAD; i++)
+ priv->pads[i].flags = MEDIA_PAD_FL_SINK;
+ ret = media_entity_pads_init(&priv->sd.entity, MAX9286_N_PADS,
+ priv->pads);
+ if (ret)
+ goto err_async;
+
+ ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), MAX9286_SRC_PAD,
+ 0, 0);
+ if (!ep) {
+ dev_err(dev, "Unable to retrieve endpoint on \"port@4\"\n");
+ ret = -ENOENT;
+ goto err_async;
+ }
+ priv->sd.fwnode = ep;
+
+ ret = v4l2_async_register_subdev(&priv->sd);
+ if (ret < 0) {
+ dev_err(dev, "Unable to register subdevice\n");
+ goto err_put_node;
+ }
+
+ return 0;
+
+err_put_node:
+ fwnode_handle_put(ep);
+err_async:
+ max9286_v4l2_notifier_unregister(priv);
+
+ return ret;
+}
+
+static void max9286_v4l2_unregister(struct max9286_priv *priv)
+{
+ fwnode_handle_put(priv->sd.fwnode);
+ v4l2_async_unregister_subdev(&priv->sd);
+ max9286_v4l2_notifier_unregister(priv);
+}
+
+/* -----------------------------------------------------------------------------
+ * Probe/Remove
+ */
+
+static int max9286_setup(struct max9286_priv *priv)
+{
+ /*
+ * Link ordering values for all enabled links combinations. Orders must
+ * be assigned sequentially from 0 to the number of enabled links
+ * without leaving any hole for disabled links. We thus assign orders to
+ * enabled links first, and use the remaining order values for disabled
+ * links are all links must have a different order value;
+ */
+ static const u8 link_order[] = {
+ (3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxxx */
+ (3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxx0 */
+ (3 << 6) | (2 << 4) | (0 << 2) | (1 << 0), /* xx0x */
+ (3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xx10 */
+ (3 << 6) | (0 << 4) | (2 << 2) | (1 << 0), /* x0xx */
+ (3 << 6) | (1 << 4) | (2 << 2) | (0 << 0), /* x1x0 */
+ (3 << 6) | (1 << 4) | (0 << 2) | (2 << 0), /* x10x */
+ (3 << 6) | (1 << 4) | (1 << 2) | (0 << 0), /* x210 */
+ (0 << 6) | (3 << 4) | (2 << 2) | (1 << 0), /* 0xxx */
+ (1 << 6) | (3 << 4) | (2 << 2) | (0 << 0), /* 1xx0 */
+ (1 << 6) | (3 << 4) | (0 << 2) | (2 << 0), /* 1x0x */
+ (2 << 6) | (3 << 4) | (1 << 2) | (0 << 0), /* 2x10 */
+ (1 << 6) | (0 << 4) | (3 << 2) | (2 << 0), /* 10xx */
+ (2 << 6) | (1 << 4) | (3 << 2) | (0 << 0), /* 21x0 */
+ (2 << 6) | (1 << 4) | (0 << 2) | (3 << 0), /* 210x */
+ (3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* 3210 */
+ };
+
+ /*
+ * Set the I2C bus speed.
+ *
+ * Enable I2C Local Acknowledge during the probe sequences of the camera
+ * only. This should be disabled after the mux is initialised.
+ */
+ max9286_configure_i2c(priv, true);
+
+ /*
+ * Reverse channel setup.
+ *
+ * - Enable custom reverse channel configuration (through register 0x3f)
+ * and set the first pulse length to 35 clock cycles.
+ * - Increase the reverse channel amplitude to 170mV to accommodate the
+ * high threshold enabled by the serializer driver.
+ */
+ max9286_write(priv, 0x3f, MAX9286_EN_REV_CFG | MAX9286_REV_FLEN(35));
+ max9286_write(priv, 0x3b, MAX9286_REV_TRF(1) | MAX9286_REV_AMP(70) |
+ MAX9286_REV_AMP_X);
+ usleep_range(2000, 2500);
+
+ /*
+ * Enable GMSL links, mask unused ones and autodetect link
+ * used as CSI clock source.
+ */
+ max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
+ max9286_write(priv, 0x0b, link_order[priv->route_mask]);
+ max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
+
+ /*
+ * Video format setup:
+ * Disable CSI output, VC is set according to Link number.
+ */
+ max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
+
+ /* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
+ max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
+ MAX9286_CSILANECNT(priv->csi2_data_lanes) |
+ MAX9286_DATATYPE_YUV422_8BIT);
+
+ /* Automatic: FRAMESYNC taken from the slowest Link. */
+ max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
+ MAX9286_FSYNCMETH_AUTO);
+
+ /* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
+ max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
+ MAX9286_HVSRC_D14);
+
+ /*
+ * Wait for 2ms to allow the link to resynchronize after the
+ * configuration change.
+ */
+ usleep_range(2000, 5000);
+
+ return 0;
+}
+
+static const struct of_device_id max9286_dt_ids[] = {
+ { .compatible = "maxim,max9286" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, max9286_dt_ids);
+
+static void max9286_gpio_set(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ struct max9286_priv *priv = gpiochip_get_data(chip);
+
+ if (value)
+ priv->gpio_state |= BIT(offset);
+ else
+ priv->gpio_state &= ~BIT(offset);
+
+ max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state);
+}
+
+static int max9286_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct max9286_priv *priv = gpiochip_get_data(chip);
+
+ return priv->gpio_state & BIT(offset);
+}
+
+static int max9286_gpio(struct max9286_priv *priv)
+{
+ struct device *dev = &priv->client->dev;
+ struct gpio_chip *gpio = &priv->gpio;
+ int ret;
+
+ static const char * const names[] = {
+ "GPIO0OUT",
+ "GPIO1OUT",
+ };
+
+ /* Configure the GPIO */
+ gpio->label = dev_name(dev);
+ gpio->parent = dev;
+ gpio->owner = THIS_MODULE;
+ gpio->of_node = dev->of_node;
+ gpio->ngpio = 2;
+ gpio->base = -1;
+ gpio->set = max9286_gpio_set;
+ gpio->get = max9286_gpio_get;
+ gpio->can_sleep = true;
+ gpio->names = names;
+
+ /* GPIO values default to high */
+ priv->gpio_state = BIT(0) | BIT(1);
+
+ ret = devm_gpiochip_add_data(dev, gpio, priv);
+ if (ret)
+ dev_err(dev, "Unable to create gpio_chip\n");
+
+ return ret;
+}
+
+static int max9286_init(struct device *dev)
+{
+ struct max9286_priv *priv;
+ struct i2c_client *client;
+ int ret;
+
+ /* Skip non-max9286 devices. */
+ if (!dev->of_node || !of_match_node(max9286_dt_ids, dev->of_node))
+ return 0;
+
+ client = to_i2c_client(dev);
+ priv = i2c_get_clientdata(client);
+
+ /* Enable the bus power. */
+ ret = regulator_enable(priv->regulator);
+ if (ret < 0) {
+ dev_err(&client->dev, "Unable to turn PoC on\n");
+ return ret;
+ }
+
+ priv->poc_enabled = true;
+
+ ret = max9286_setup(priv);
+ if (ret) {
+ dev_err(dev, "Unable to setup max9286\n");
+ goto err_regulator;
+ }
+
+ /*
+ * Register all V4L2 interactions for the MAX9286 and notifiers for
+ * any subdevices connected.
+ */
+ ret = max9286_v4l2_register(priv);
+ if (ret) {
+ dev_err(dev, "Failed to register with V4L2\n");
+ goto err_regulator;
+ }
+
+ ret = max9286_i2c_mux_init(priv);
+ if (ret) {
+ dev_err(dev, "Unable to initialize I2C multiplexer\n");
+ goto err_v4l2_register;
+ }
+
+ /* Leave the mux channels disabled until they are selected. */
+ max9286_i2c_mux_close(priv);
+
+ return 0;
+
+err_v4l2_register:
+ max9286_v4l2_unregister(priv);
+err_regulator:
+ regulator_disable(priv->regulator);
+ priv->poc_enabled = false;
+
+ return ret;
+}
+
+static void max9286_cleanup_dt(struct max9286_priv *priv)
+{
+ struct max9286_source *source;
+
+ for_each_source(priv, source) {
+ fwnode_handle_put(source->fwnode);
+ source->fwnode = NULL;
+ }
+}
+
+static int max9286_parse_dt(struct max9286_priv *priv)
+{
+ struct device *dev = &priv->client->dev;
+ struct device_node *i2c_mux;
+ struct device_node *node = NULL;
+ unsigned int i2c_mux_mask = 0;
+
+ of_node_get(dev->of_node);
+ i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
+ if (!i2c_mux) {
+ dev_err(dev, "Failed to find i2c-mux node\n");
+ return -EINVAL;
+ }
+
+ /* Identify which i2c-mux channels are enabled */
+ for_each_child_of_node(i2c_mux, node) {
+ u32 id = 0;
+
+ of_property_read_u32(node, "reg", &id);
+ if (id >= MAX9286_NUM_GMSL)
+ continue;
+
+ if (!of_device_is_available(node)) {
+ dev_dbg(dev, "Skipping disabled I2C bus port %u\n",
+ id);
+ continue;
+ }
+
+ i2c_mux_mask |= BIT(id);
+ }
+ of_node_put(node);
+ of_node_put(i2c_mux);
+
+ /* Parse the endpoints */
+ for_each_endpoint_of_node(dev->of_node, node) {
+ struct max9286_source *source;
+ struct of_endpoint ep;
+
+ of_graph_parse_endpoint(node, &ep);
+ dev_dbg(dev, "Endpoint %pOF on port %d",
+ ep.local_node, ep.port);
+
+ if (ep.port > MAX9286_NUM_GMSL) {
+ dev_err(dev, "Invalid endpoint %s on port %d",
+ of_node_full_name(ep.local_node), ep.port);
+ continue;
+ }
+
+ /* For the source endpoint just parse the bus configuration. */
+ if (ep.port == MAX9286_SRC_PAD) {
+ struct v4l2_fwnode_endpoint vep = {
+ .bus_type = V4L2_MBUS_CSI2_DPHY
+ };
+ int ret;
+
+ ret = v4l2_fwnode_endpoint_parse(
+ of_fwnode_handle(node), &vep);
+ if (ret) {
+ of_node_put(node);
+ return ret;
+ }
+
+ if (vep.bus_type != V4L2_MBUS_CSI2_DPHY) {
+ dev_err(dev,
+ "Media bus %u type not supported\n",
+ vep.bus_type);
+ v4l2_fwnode_endpoint_free(&vep);
+ of_node_put(node);
+ return -EINVAL;
+ }
+
+ priv->csi2_data_lanes =
+ vep.bus.mipi_csi2.num_data_lanes;
+ v4l2_fwnode_endpoint_free(&vep);
+
+ continue;
+ }
+
+ /* Skip if the corresponding GMSL link is unavailable. */
+ if (!(i2c_mux_mask & BIT(ep.port)))
+ continue;
+
+ if (priv->sources[ep.port].fwnode) {
+ dev_err(dev,
+ "Multiple port endpoints are not supported: %d",
+ ep.port);
+
+ continue;
+ }
+
+ source = &priv->sources[ep.port];
+ source->fwnode = fwnode_graph_get_remote_endpoint(
+ of_fwnode_handle(node));
+ if (!source->fwnode) {
+ dev_err(dev,
+ "Endpoint %pOF has no remote endpoint connection\n",
+ ep.local_node);
+
+ continue;
+ }
+
+ priv->source_mask |= BIT(ep.port);
+ priv->nsources++;
+ }
+ of_node_put(node);
+
+ priv->route_mask = priv->source_mask;
+
+ return 0;
+}
+
+static int max9286_probe(struct i2c_client *client)
+{
+ struct max9286_priv *priv;
+ unsigned int i;
+ int ret;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->client = client;
+ i2c_set_clientdata(client, priv);
+
+ for (i = 0; i < MAX9286_N_SINKS; i++)
+ max9286_init_format(&priv->fmt[i]);
+
+ ret = max9286_parse_dt(priv);
+ if (ret)
+ return ret;
+
+ priv->gpiod_pwdn = devm_gpiod_get_optional(&client->dev, "enable",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(priv->gpiod_pwdn))
+ return PTR_ERR(priv->gpiod_pwdn);
+
+ gpiod_set_consumer_name(priv->gpiod_pwdn, "max9286-pwdn");
+ gpiod_set_value_cansleep(priv->gpiod_pwdn, 1);
+
+ /* Wait at least 4ms before the I2C lines latch to the address */
+ if (priv->gpiod_pwdn)
+ usleep_range(4000, 5000);
+
+ ret = max9286_gpio(priv);
+ if (ret)
+ return ret;
+
+ priv->regulator = regulator_get(&client->dev, "poc");
+ if (IS_ERR(priv->regulator)) {
+ if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
+ dev_err(&client->dev,
+ "Unable to get PoC regulator (%ld)\n",
+ PTR_ERR(priv->regulator));
+ ret = PTR_ERR(priv->regulator);
+ priv->regulator = NULL;
+ goto err_free;
+ }
+
+ /*
+ * We can have multiple MAX9286 instances on the same physical I2C
+ * bus, and I2C children behind ports of separate MAX9286 instances
+ * having the same I2C address. As the MAX9286 starts by default with
+ * all ports enabled, we need to disable all ports on all MAX9286
+ * instances before proceeding to further initialize the devices and
+ * instantiate children.
+ *
+ * Start by just disabling all channels on the current device. Then,
+ * if all other MAX9286 on the parent bus have been probed, proceed
+ * to initialize them all, including the current one.
+ */
+ max9286_i2c_mux_close(priv);
+
+ /*
+ * The MAX9286 initialises with auto-acknowledge enabled by default.
+ * This means that if multiple MAX9286 devices are connected to an I2C
+ * bus, another MAX9286 could ack I2C transfers meant for a device on
+ * the other side of the GMSL links for this MAX9286 (such as a
+ * MAX9271). To prevent that disable auto-acknowledge early on; it
+ * will be enabled later as needed.
+ */
+ max9286_configure_i2c(priv, false);
+
+ ret = max9286_init(&client->dev);
+ if (ret < 0)
+ goto err_regulator;
+
+ return 0;
+
+err_regulator:
+ regulator_put(priv->regulator);
+ max9286_i2c_mux_close(priv);
+ max9286_configure_i2c(priv, false);
+err_free:
+ max9286_cleanup_dt(priv);
+ kfree(priv);
+
+ return ret;
+}
+
+static int max9286_remove(struct i2c_client *client)
+{
+ struct max9286_priv *priv = i2c_get_clientdata(client);
+
+ i2c_mux_del_adapters(priv->mux);
+
+ max9286_v4l2_unregister(priv);
+
+ if (priv->poc_enabled)
+ regulator_disable(priv->regulator);
+ regulator_put(priv->regulator);
+
+ max9286_cleanup_dt(priv);
+
+ gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
+
+ kfree(priv);
+
+ return 0;
+}
+
+static const struct i2c_device_id max9286_id[] = {
+ { "max9286", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, max9286_id);
+
+static struct i2c_driver max9286_i2c_driver = {
+ .driver = {
+ .name = "max9286",
+ .of_match_table = of_match_ptr(max9286_dt_ids),
+ },
+ .probe_new = max9286_probe,
+ .remove = max9286_remove,
+ .id_table = max9286_id,
+};
+
+module_i2c_driver(max9286_i2c_driver);
+
+MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
+MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
+MODULE_LICENSE("GPL");
--
2.20.1
