Re: [PATCH v9 2/4] media: i2c: Add MAX9286 driver

From: Kieran Bingham
Date: Thu May 14 2020 - 05:53:20 EST

Hi Mani,

On 12/05/2020 18:40, Manivannan Sadhasivam wrote:
> Hi Kieran,
>
> On Tue, May 12, 2020 at 04:51:03PM +0100, Kieran Bingham wrote:
>> 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 SÃderlund <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
>>
>> v8:
>>
>> [Kieran]
>> - Update the bound_sources mask on unbind
>> - Convert probe kzalloc usage to devm_ variant
>> - Fix up cleanup path from GPIO PowerDown registration
>> - cleanup GPIO device registration fail path
>> - Convert to use devm_regulator_get()
>> - Fit max9286_parse_dt print on one line
>> - Move multi-device workarounds out of upstream driver
>> - Remove I2C mod-table
>> - Lock format changes
>> - Describe pad index usage
>> - Remove poc_enabled workaround
>> - Rename the max9286_gpio to be more explicit on it's actions.
>> - Move max9286_init_format call
>> - Rework probe sequence and simplify error paths.
>> - Simplify i2c comments
>> - Implement Pixelrate control
>> - Disable overlap window
>>
>> [Jacopo]
>> - Adapt Kconfig to latest upstream changes
>> - Put of node on error
>> - Calculate pixel rate
>> - Simplify overlap window disablement
>>
>> v9:
>>
>> [Kieran]
>> - Kconfig: Depend on OF
>> - Re-sort addition to Makefile
>> ---
>> MAINTAINERS | 10 +
>> drivers/media/i2c/Kconfig | 13 +
>> drivers/media/i2c/Makefile | 1 +
>> drivers/media/i2c/max9286.c | 1332 +++++++++++++++++++++++++++++++++++
>> 4 files changed, 1356 insertions(+)
>> create mode 100644 drivers/media/i2c/max9286.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index a7bb6e22d5da..99e3bf7760fd 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10274,6 +10274,16 @@ F: Documentation/hwmon/max6697.rst
>> 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 SÃderlund <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 3abc80373ec0..2e390f41f6da 100644
>> --- a/drivers/media/i2c/Kconfig
>> +++ b/drivers/media/i2c/Kconfig
>> @@ -464,6 +464,19 @@ 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 OF
>> + select V4L2_FWNODE
>> + select VIDEO_V4L2_SUBDEV_API
>> + select MEDIA_CONTROLLER
>> + 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 77bf7d0b691f..f0b001ee4b05 100644
>> --- a/drivers/media/i2c/Makefile
>> +++ b/drivers/media/i2c/Makefile
>> @@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_IMX274) += imx274.o
>> obj-$(CONFIG_VIDEO_IMX290) += imx290.o
>> obj-$(CONFIG_VIDEO_IMX319) += imx319.o
>> obj-$(CONFIG_VIDEO_IMX355) += imx355.o
>> +obj-$(CONFIG_VIDEO_MAX9286) += max9286.o
>> obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.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..481d65f2b51d
>> --- /dev/null
>> +++ b/drivers/media/i2c/max9286.c
>> @@ -0,0 +1,1332 @@
>> +// 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 SÃderlund
>> + * 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/mutex.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)
>> +
>> +/*
>> + * The sink and source pads are created to match the OF graph port numbers so
>> + * that their indexes can be used interchangeably.
>> + */
>> +#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;
>> +
>> + 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_ctrl *pixelrate;
>> +
>> + struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
>> +
>> + /* Protects controls and fmt structures */
>> + struct mutex mutex;
>> +
>> + 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_set_pixelrate(struct max9286_priv *priv)
>> +{
>> + struct max9286_source *source = NULL;
>> + u64 pixelrate = 0;
>> +
>> + for_each_source(priv, source) {
>> + struct v4l2_ctrl *ctrl;
>> + u64 source_rate = 0;
>> +
>> + /* Pixel rate is mandatory to be reported by sources. */
>> + ctrl = v4l2_ctrl_find(source->sd->ctrl_handler,
>> + V4L2_CID_PIXEL_RATE);
>> + if (!ctrl) {
>> + pixelrate = 0;
>> + break;
>> + }
>> +
>> + /* All source must report the same pixel rate. */
>> + source_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
>> + if (!pixelrate) {
>> + pixelrate = source_rate;
>> + } else if (pixelrate != source_rate) {
>> + dev_err(&priv->client->dev,
>> + "Unable to calculate pixel rate\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + if (!pixelrate) {
>> + dev_err(&priv->client->dev,
>> + "No pixel rate control available in sources\n");
>> + return -EINVAL;
>> + }
>> +
>> + /*
>> + * The CSI-2 transmitter pixel rate is the single source rate multiplied
>> + * by the number of available sources.
>> + */
>> + return v4l2_ctrl_s_ctrl_int64(priv->pixelrate,
>> + pixelrate * priv->nsources);
>> +}
>> +
>> +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 remote 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 max9286_set_pixelrate(priv);
>> +}
>> +
>> +static void max9286_notify_unbind(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);
>> +
>> + source->sd = NULL;
>> + priv->bound_sources &= ~BIT(index);
>> +}
>> +
>> +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;
>
> Is there any reason for not setting default format to MEDIA_BUS_FMT_UYVY8_2X8?
>


No good reason no, and I see that in max9286_enum_mbus_code(), we
currently code to MEDIA_BUS_FMT_YUYV8_2X8, and that's the value that we
init to, so that would be a better default indeed.

I'll update this for v10.


> Thanks,
> Mani
>
>> + break;
>> + }
>> +
>> + cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
>> + if (!cfg_fmt)
>> + return -EINVAL;
>> +
>> + mutex_lock(&priv->mutex);
>> + *cfg_fmt = format->format;
>> + mutex_unlock(&priv->mutex);
>> +
>> + 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;
>> +
>> + mutex_lock(&priv->mutex);
>> + format->format = *cfg_fmt;
>> + mutex_unlock(&priv->mutex);
>> +
>> + 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_s_ctrl(struct v4l2_ctrl *ctrl)
>> +{
>> + switch (ctrl->id) {
>> + case V4L2_CID_PIXEL_RATE:
>> + return 0;
>> + default:
>> + return -EINVAL;
>> + }
>> +}
>> +
>> +static const struct v4l2_ctrl_ops max9286_ctrl_ops = {
>> + .s_ctrl = max9286_s_ctrl,
>> +};
>> +
>> +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 */
>> +
>> + for (i = 0; i < MAX9286_N_SINKS; i++)
>> + max9286_init_format(&priv->fmt[i]);
>> +
>> + 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);
>> + priv->pixelrate = v4l2_ctrl_new_std(&priv->ctrls,
>> + &max9286_ctrl_ops,
>> + V4L2_CID_PIXEL_RATE,
>> + 1, INT_MAX, 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);
>> +
>> + /*
>> + * The overlap window seems to provide additional validation by tracking
>> + * the delay between vsync and frame sync, generating an error if the
>> + * delay is bigger than the programmed window, though it's not yet clear
>> + * what value should be set.
>> + *
>> + * As it's an optional value and can be disabled, we do so by setting
>> + * a 0 overlap value.
>> + */
>> + max9286_write(priv, 0x63, 0);
>> + max9286_write(priv, 0x64, 0);
>> +
>> + /*
>> + * Wait for 2ms to allow the link to resynchronize after the
>> + * configuration change.
>> + */
>> + usleep_range(2000, 5000);
>> +
>> + return 0;
>> +}
>> +
>> +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_register_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;
>> +
>> + 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;
>> + }
>> +
>> + 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);
>> +
>> + 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");
>> + of_node_put(dev->of_node);
>> + 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);
>> + of_node_put(dev->of_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);
>> + of_node_put(dev->of_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);
>> + of_node_put(dev->of_node);
>> +
>> + priv->route_mask = priv->source_mask;
>> +
>> + return 0;
>> +}
>> +
>> +static int max9286_probe(struct i2c_client *client)
>> +{
>> + struct max9286_priv *priv;
>> + int ret;
>> +
>> + priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
>> + if (!priv)
>> + return -ENOMEM;
>> +
>> + mutex_init(&priv->mutex);
>> +
>> + priv->client = client;
>> + i2c_set_clientdata(client, priv);
>> +
>> + 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);
>> +
>> + /*
>> + * The MAX9286 starts by default with all ports enabled, we disable all
>> + * ports early to ensure that all channels are disabled if we error out
>> + * and keep the bus consistent.
>> + */
>> + max9286_i2c_mux_close(priv);
>> +
>> + /*
>> + * The MAX9286 initialises with auto-acknowledge enabled by default.
>> + * This can be invasive to other transactions on the same bus, so
>> + * disable it early. It will be enabled only as and when needed.
>> + */
>> + max9286_configure_i2c(priv, false);
>> +
>> + ret = max9286_register_gpio(priv);
>> + if (ret)
>> + goto err_powerdown;
>> +
>> + priv->regulator = devm_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);
>> + goto err_powerdown;
>> + }
>> +
>> + ret = max9286_parse_dt(priv);
>> + if (ret)
>> + goto err_powerdown;
>> +
>> + ret = max9286_init(&client->dev);
>> + if (ret < 0)
>> + goto err_cleanup_dt;
>> +
>> + return 0;
>> +
>> +err_cleanup_dt:
>> + max9286_cleanup_dt(priv);
>> +err_powerdown:
>> + gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>> +
>> + 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);
>> +
>> + regulator_disable(priv->regulator);
>> +
>> + gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
>> +
>> + max9286_cleanup_dt(priv);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id max9286_dt_ids[] = {
>> + { .compatible = "maxim,max9286" },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, max9286_dt_ids);
>> +
>> +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,
>> +};
>> +
>> +module_i2c_driver(max9286_i2c_driver);
>> +
>> +MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
>> +MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas SÃderlund, Vladimir Barinov");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.25.1
>>