diff mbox series

[v2,5/7] platform/chrome: cros_ec_typec: Displayport support

Message ID 20241030142833.v2.5.I142fc0c09df58689b98f0cebf1c5e48b9d4fa800@changeid (mailing list archive)
State New
Headers show
Series Thunderbolt and DP altmode support for cros-ec-typec | expand

Commit Message

Abhishek Pandit-Subedi Oct. 30, 2024, 9:28 p.m. UTC
Add support for entering and exiting displayport alt-mode on systems
using AP driven alt-mode.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v2:
- Refactored displayport into cros_typec_altmode.c to extract common
  implementation between altmodes

 MAINTAINERS                                  |   3 +
 drivers/platform/chrome/Makefile             |   3 +-
 drivers/platform/chrome/cros_ec_typec.c      |  13 +-
 drivers/platform/chrome/cros_ec_typec.h      |   1 +
 drivers/platform/chrome/cros_typec_altmode.c | 277 +++++++++++++++++++
 drivers/platform/chrome/cros_typec_altmode.h |  34 +++
 6 files changed, 329 insertions(+), 2 deletions(-)
 create mode 100644 drivers/platform/chrome/cros_typec_altmode.c
 create mode 100644 drivers/platform/chrome/cros_typec_altmode.h

Comments

kernel test robot Oct. 31, 2024, 5:48 p.m. UTC | #1
Hi Abhishek,

kernel test robot noticed the following build warnings:

[auto build test WARNING on chrome-platform/for-next]
[also build test WARNING on chrome-platform/for-firmware-next usb/usb-testing usb/usb-next usb/usb-linus westeri-thunderbolt/next linus/master v6.12-rc5 next-20241031]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Abhishek-Pandit-Subedi/usb-typec-Add-driver-for-Thunderbolt-3-Alternate-Mode/20241031-053304
base:   https://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux.git for-next
patch link:    https://lore.kernel.org/r/20241030142833.v2.5.I142fc0c09df58689b98f0cebf1c5e48b9d4fa800%40changeid
patch subject: [PATCH v2 5/7] platform/chrome: cros_ec_typec: Displayport support
config: arm-defconfig (https://download.01.org/0day-ci/archive/20241101/202411010134.yJIy0Z3P-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241101/202411010134.yJIy0Z3P-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411010134.yJIy0Z3P-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/platform/chrome/cros_typec_altmode.c:40:13: warning: unused function 'cros_typec_altmode_work' [-Wunused-function]
   static void cros_typec_altmode_work(struct work_struct *work)
               ^
>> drivers/platform/chrome/cros_typec_altmode.c:212:39: warning: unused variable 'cros_typec_altmode_ops' [-Wunused-const-variable]
   static const struct typec_altmode_ops cros_typec_altmode_ops = {
                                         ^
   2 warnings generated.


vim +/cros_typec_altmode_ops +212 drivers/platform/chrome/cros_typec_altmode.c

    39	
  > 40	static void cros_typec_altmode_work(struct work_struct *work)
    41	{
    42		struct cros_typec_altmode_data *data =
    43			container_of(work, struct cros_typec_altmode_data, work);
    44	
    45		if (typec_altmode_vdm(data->alt, data->header, data->vdo_data,
    46				      data->vdo_size))
    47			dev_err(&data->alt->dev, "VDM 0x%x failed", data->header);
    48	
    49		data->header = 0;
    50		data->vdo_data = NULL;
    51		data->vdo_size = 0;
    52	}
    53	
    54	static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
    55	{
    56		struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
    57		struct ec_params_typec_control req = {
    58			.port = data->port->port_num,
    59			.command = TYPEC_CONTROL_COMMAND_ENTER_MODE,
    60		};
    61		int svdm_version;
    62		int ret;
    63	
    64		if (!data->ap_mode_entry) {
    65			const struct typec_altmode *partner =
    66				typec_altmode_get_partner(alt);
    67			dev_warn(&partner->dev,
    68				 "EC does not support ap driven mode entry\n");
    69			return -EOPNOTSUPP;
    70		}
    71	
    72		if (data->sid == USB_TYPEC_DP_SID)
    73			req.mode_to_enter = CROS_EC_ALTMODE_DP;
    74		else
    75			return -EOPNOTSUPP;
    76	
    77		ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
    78				  &req, sizeof(req), NULL, 0);
    79		if (ret < 0)
    80			return ret;
    81	
    82		svdm_version = typec_altmode_get_svdm_version(alt);
    83		if (svdm_version < 0)
    84			return svdm_version;
    85	
    86		data->header = VDO(data->sid, 1, svdm_version, CMD_ENTER_MODE);
    87		data->header |= VDO_OPOS(data->mode);
    88		data->header |= VDO_CMDT(CMDT_RSP_ACK);
    89	
    90		data->vdo_data = NULL;
    91		data->vdo_size = 1;
    92	
    93		schedule_work(&data->work);
    94	
    95		return ret;
    96	}
    97	
    98	static int cros_typec_altmode_exit(struct typec_altmode *alt)
    99	{
   100		struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
   101		struct ec_params_typec_control req = {
   102			.port = data->port->port_num,
   103			.command = TYPEC_CONTROL_COMMAND_EXIT_MODES,
   104		};
   105		int svdm_version;
   106		int ret;
   107	
   108		if (!data->ap_mode_entry) {
   109			const struct typec_altmode *partner =
   110				typec_altmode_get_partner(alt);
   111			dev_warn(&partner->dev,
   112				 "EC does not support ap driven mode entry\n");
   113			return -EOPNOTSUPP;
   114		}
   115	
   116		ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
   117				  &req, sizeof(req), NULL, 0);
   118	
   119		if (ret < 0)
   120			return ret;
   121	
   122		svdm_version = typec_altmode_get_svdm_version(alt);
   123		if (svdm_version < 0)
   124			return svdm_version;
   125	
   126		data->header = VDO(data->sid, 1, svdm_version, CMD_EXIT_MODE);
   127		data->header |= VDO_OPOS(data->mode);
   128		data->header |= VDO_CMDT(CMDT_RSP_ACK);
   129	
   130		data->vdo_data = NULL;
   131		data->vdo_size = 1;
   132	
   133		schedule_work(&data->work);
   134	
   135		return ret;
   136	}
   137	
   138	static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
   139					      const u32 *data, int count)
   140	{
   141		struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
   142	
   143		int cmd_type = PD_VDO_CMDT(header);
   144		int cmd = PD_VDO_CMD(header);
   145		int svdm_version;
   146	
   147		if (!adata->ap_mode_entry) {
   148			const struct typec_altmode *partner =
   149				typec_altmode_get_partner(alt);
   150			dev_warn(&partner->dev,
   151				 "EC does not support ap driven mode entry\n");
   152			return -EOPNOTSUPP;
   153		}
   154	
   155		svdm_version = typec_altmode_get_svdm_version(alt);
   156		if (svdm_version < 0)
   157			return svdm_version;
   158	
   159		switch (cmd_type) {
   160		case CMDT_INIT:
   161			if (PD_VDO_SVDM_VER(header) < svdm_version) {
   162				typec_partner_set_svdm_version(adata->port->partner,
   163							       PD_VDO_SVDM_VER(header));
   164				svdm_version = PD_VDO_SVDM_VER(header);
   165			}
   166	
   167			adata->header = VDO(adata->sid, 1, svdm_version, cmd);
   168			adata->header |= VDO_OPOS(adata->mode);
   169	
   170			/*
   171			 * DP_CMD_CONFIGURE: We can't actually do anything with the
   172			 * provided VDO yet so just send back an ACK.
   173			 *
   174			 * DP_CMD_STATUS_UPDATE: We wait for Mux changes to send
   175			 * DPStatus Acks.
   176			 */
   177			switch (cmd) {
   178			case DP_CMD_CONFIGURE:
   179				adata->am_data.dp.data.conf = *data;
   180				adata->header |= VDO_CMDT(CMDT_RSP_ACK);
   181				adata->am_data.dp.configured = true;
   182				schedule_work(&adata->work);
   183				break;
   184			case DP_CMD_STATUS_UPDATE:
   185				adata->am_data.dp.pending_status_update = true;
   186				break;
   187			default:
   188				adata->header |= VDO_CMDT(CMDT_RSP_ACK);
   189				schedule_work(&adata->work);
   190				break;
   191			}
   192	
   193			break;
   194		default:
   195			break;
   196		}
   197	
   198		return 0;
   199	}
   200	
   201	static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
   202					      const u32 *data, int count)
   203	{
   204		struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
   205	
   206		if (adata->sid == USB_TYPEC_DP_SID)
   207			return cros_typec_displayport_vdm(alt, header, data, count);
   208	
   209		return -EINVAL;
   210	}
   211	
 > 212	static const struct typec_altmode_ops cros_typec_altmode_ops = {
   213		.enter = cros_typec_altmode_enter,
   214		.exit = cros_typec_altmode_exit,
   215		.vdm = cros_typec_altmode_vdm,
   216	};
   217
Dmitry Baryshkov Oct. 31, 2024, 6:54 p.m. UTC | #2
On Wed, Oct 30, 2024 at 02:28:36PM -0700, Abhishek Pandit-Subedi wrote:
> Add support for entering and exiting displayport alt-mode on systems
> using AP driven alt-mode.
> 
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> ---
> 
> Changes in v2:
> - Refactored displayport into cros_typec_altmode.c to extract common
>   implementation between altmodes

Thanks!

> 
>  MAINTAINERS                                  |   3 +
>  drivers/platform/chrome/Makefile             |   3 +-
>  drivers/platform/chrome/cros_ec_typec.c      |  13 +-
>  drivers/platform/chrome/cros_ec_typec.h      |   1 +
>  drivers/platform/chrome/cros_typec_altmode.c | 277 +++++++++++++++++++
>  drivers/platform/chrome/cros_typec_altmode.h |  34 +++
>  6 files changed, 329 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/platform/chrome/cros_typec_altmode.c
>  create mode 100644 drivers/platform/chrome/cros_typec_altmode.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e9659a5a7fb3..de99bcbda7d4 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5369,9 +5369,12 @@ F:	include/linux/platform_data/cros_usbpd_notify.h
>  
>  CHROMEOS EC USB TYPE-C DRIVER
>  M:	Prashant Malani <pmalani@chromium.org>
> +M:	Benson Leung <bleung@chromium.org>
> +M:	Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
>  L:	chrome-platform@lists.linux.dev
>  S:	Maintained
>  F:	drivers/platform/chrome/cros_ec_typec.*
> +F:	drivers/platform/chrome/cros_typec_altmode.*
>  F:	drivers/platform/chrome/cros_typec_switch.c
>  F:	drivers/platform/chrome/cros_typec_vdm.*
>  
> diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
> index 2dcc6ccc2302..8b007404c024 100644
> --- a/drivers/platform/chrome/Makefile
> +++ b/drivers/platform/chrome/Makefile
> @@ -17,8 +17,9 @@ obj-$(CONFIG_CROS_EC_RPMSG)		+= cros_ec_rpmsg.o
>  obj-$(CONFIG_CROS_EC_SPI)		+= cros_ec_spi.o
>  obj-$(CONFIG_CROS_EC_UART)		+= cros_ec_uart.o
>  cros_ec_lpcs-objs			:= cros_ec_lpc.o cros_ec_lpc_mec.o
> -cros-ec-typec-objs			:= cros_ec_typec.o cros_typec_vdm.o
> +cros-ec-typec-objs			:= cros_ec_typec.o cros_typec_vdm.o cros_typec_altmode.o
>  obj-$(CONFIG_CROS_EC_TYPEC)		+= cros-ec-typec.o
> +
>  obj-$(CONFIG_CROS_EC_LPC)		+= cros_ec_lpcs.o
>  obj-$(CONFIG_CROS_EC_PROTO)		+= cros_ec_proto.o cros_ec_trace.o
>  obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT)	+= cros_kbd_led_backlight.o
> diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> index 0c8db11bd8a4..7997e7136c4c 100644
> --- a/drivers/platform/chrome/cros_ec_typec.c
> +++ b/drivers/platform/chrome/cros_ec_typec.c
> @@ -18,6 +18,7 @@
>  
>  #include "cros_ec_typec.h"
>  #include "cros_typec_vdm.h"
> +#include "cros_typec_altmode.h"
>  
>  #define DRV_NAME "cros-ec-typec"
>  
> @@ -293,12 +294,16 @@ static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
>  	desc.svid = USB_TYPEC_DP_SID;
>  	desc.mode = USB_TYPEC_DP_MODE;
>  	desc.vdo = DP_PORT_VDO;
> -	amode = typec_port_register_altmode(port->port, &desc);
> +	amode = cros_typec_register_displayport(port, &desc,
> +						typec->ap_driven_altmode);
>  	if (IS_ERR(amode))
>  		return PTR_ERR(amode);
>  	port->port_altmode[CROS_EC_ALTMODE_DP] = amode;
> +
> +#if !IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
>  	typec_altmode_set_drvdata(amode, port);
>  	amode->ops = &port_amode_ops;
> +#endif
>  
>  	/*
>  	 * Register TBT compatibility alt mode. The EC will not enter the mode
> @@ -575,6 +580,10 @@ static int cros_typec_enable_dp(struct cros_typec_data *typec,
>  	if (!ret)
>  		ret = typec_mux_set(port->mux, &port->state);
>  
> +	if (!ret)
> +		cros_typec_displayport_status_update(port->state.alt,
> +						     port->state.data);
> +
>  	return ret;
>  }
>  
> @@ -1254,6 +1263,8 @@ static int cros_typec_probe(struct platform_device *pdev)
>  
>  	typec->typec_cmd_supported = cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_CMD);
>  	typec->needs_mux_ack = cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
> +	typec->ap_driven_altmode = cros_ec_check_features(
> +		ec_dev, EC_FEATURE_TYPEC_REQUIRE_AP_MODE_ENTRY);
>  
>  	ret = cros_ec_cmd(typec->ec, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
>  			  &resp, sizeof(resp));
> diff --git a/drivers/platform/chrome/cros_ec_typec.h b/drivers/platform/chrome/cros_ec_typec.h
> index deda180a646f..9fd5342bb0ad 100644
> --- a/drivers/platform/chrome/cros_ec_typec.h
> +++ b/drivers/platform/chrome/cros_ec_typec.h
> @@ -39,6 +39,7 @@ struct cros_typec_data {
>  	struct work_struct port_work;
>  	bool typec_cmd_supported;
>  	bool needs_mux_ack;
> +	bool ap_driven_altmode;
>  };
>  
>  /* Per port data. */
> diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
> new file mode 100644
> index 000000000000..af2f077674f1
> --- /dev/null
> +++ b/drivers/platform/chrome/cros_typec_altmode.c
> @@ -0,0 +1,277 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Alt-mode implementation on ChromeOS EC.
> + *
> + * Copyright 2024 Google LLC
> + * Author: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> + */
> +#include "cros_ec_typec.h"
> +
> +#include <linux/usb/typec_dp.h>
> +#include <linux/usb/pd_vdo.h>
> +
> +#include "cros_typec_altmode.h"
> +
> +struct cros_typec_dp_data {
> +	struct typec_displayport_data data;
> +
> +	bool configured;
> +	bool pending_status_update;
> +};
> +
> +struct cros_typec_altmode_data {
> +	struct work_struct work;
> +	struct cros_typec_port *port;
> +	struct typec_altmode *alt;
> +	bool ap_mode_entry;
> +
> +	u32 header;
> +	u32 *vdo_data;
> +	u8 vdo_size;
> +
> +	u16 sid;
> +	u8 mode;
> +
> +	union am_specific {
> +		struct cros_typec_dp_data dp;
> +	} am_data;

Can this be done other way around?

struct cros_typec_dp_altmode_data {
  struct cros_typec_altmode_data base;
  struct cros_typec_dp_data dp;
};

> +};
> +
> +static void cros_typec_altmode_work(struct work_struct *work)
> +{
> +	struct cros_typec_altmode_data *data =
> +		container_of(work, struct cros_typec_altmode_data, work);
> +
> +	if (typec_altmode_vdm(data->alt, data->header, data->vdo_data,
> +			      data->vdo_size))
> +		dev_err(&data->alt->dev, "VDM 0x%x failed", data->header);
> +
> +	data->header = 0;
> +	data->vdo_data = NULL;
> +	data->vdo_size = 0;
> +}
> +
> +static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
> +{
> +	struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
> +	struct ec_params_typec_control req = {
> +		.port = data->port->port_num,
> +		.command = TYPEC_CONTROL_COMMAND_ENTER_MODE,
> +	};
> +	int svdm_version;
> +	int ret;
> +
> +	if (!data->ap_mode_entry) {
> +		const struct typec_altmode *partner =
> +			typec_altmode_get_partner(alt);
> +		dev_warn(&partner->dev,
> +			 "EC does not support ap driven mode entry\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (data->sid == USB_TYPEC_DP_SID)
> +		req.mode_to_enter = CROS_EC_ALTMODE_DP;
> +	else
> +		return -EOPNOTSUPP;
> +
> +	ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
> +			  &req, sizeof(req), NULL, 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	svdm_version = typec_altmode_get_svdm_version(alt);
> +	if (svdm_version < 0)
> +		return svdm_version;
> +
> +	data->header = VDO(data->sid, 1, svdm_version, CMD_ENTER_MODE);
> +	data->header |= VDO_OPOS(data->mode);
> +	data->header |= VDO_CMDT(CMDT_RSP_ACK);
> +
> +	data->vdo_data = NULL;
> +	data->vdo_size = 1;
> +
> +	schedule_work(&data->work);
> +
> +	return ret;
> +}
> +
> +static int cros_typec_altmode_exit(struct typec_altmode *alt)
> +{
> +	struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
> +	struct ec_params_typec_control req = {
> +		.port = data->port->port_num,
> +		.command = TYPEC_CONTROL_COMMAND_EXIT_MODES,
> +	};
> +	int svdm_version;
> +	int ret;
> +
> +	if (!data->ap_mode_entry) {
> +		const struct typec_altmode *partner =
> +			typec_altmode_get_partner(alt);
> +		dev_warn(&partner->dev,
> +			 "EC does not support ap driven mode entry\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
> +			  &req, sizeof(req), NULL, 0);
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	svdm_version = typec_altmode_get_svdm_version(alt);
> +	if (svdm_version < 0)
> +		return svdm_version;
> +
> +	data->header = VDO(data->sid, 1, svdm_version, CMD_EXIT_MODE);
> +	data->header |= VDO_OPOS(data->mode);
> +	data->header |= VDO_CMDT(CMDT_RSP_ACK);
> +
> +	data->vdo_data = NULL;
> +	data->vdo_size = 1;
> +
> +	schedule_work(&data->work);
> +
> +	return ret;
> +}
> +
> +static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
> +				      const u32 *data, int count)
> +{
> +	struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
> +
> +	int cmd_type = PD_VDO_CMDT(header);
> +	int cmd = PD_VDO_CMD(header);
> +	int svdm_version;
> +
> +	if (!adata->ap_mode_entry) {
> +		const struct typec_altmode *partner =
> +			typec_altmode_get_partner(alt);
> +		dev_warn(&partner->dev,
> +			 "EC does not support ap driven mode entry\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	svdm_version = typec_altmode_get_svdm_version(alt);
> +	if (svdm_version < 0)
> +		return svdm_version;
> +
> +	switch (cmd_type) {
> +	case CMDT_INIT:
> +		if (PD_VDO_SVDM_VER(header) < svdm_version) {
> +			typec_partner_set_svdm_version(adata->port->partner,
> +						       PD_VDO_SVDM_VER(header));
> +			svdm_version = PD_VDO_SVDM_VER(header);
> +		}
> +
> +		adata->header = VDO(adata->sid, 1, svdm_version, cmd);
> +		adata->header |= VDO_OPOS(adata->mode);
> +
> +		/*
> +		 * DP_CMD_CONFIGURE: We can't actually do anything with the
> +		 * provided VDO yet so just send back an ACK.
> +		 *
> +		 * DP_CMD_STATUS_UPDATE: We wait for Mux changes to send
> +		 * DPStatus Acks.
> +		 */
> +		switch (cmd) {
> +		case DP_CMD_CONFIGURE:
> +			adata->am_data.dp.data.conf = *data;
> +			adata->header |= VDO_CMDT(CMDT_RSP_ACK);
> +			adata->am_data.dp.configured = true;
> +			schedule_work(&adata->work);
> +			break;
> +		case DP_CMD_STATUS_UPDATE:
> +			adata->am_data.dp.pending_status_update = true;
> +			break;
> +		default:
> +			adata->header |= VDO_CMDT(CMDT_RSP_ACK);
> +			schedule_work(&adata->work);
> +			break;
> +		}
> +
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
> +				      const u32 *data, int count)
> +{
> +	struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
> +
> +	if (adata->sid == USB_TYPEC_DP_SID)
> +		return cros_typec_displayport_vdm(alt, header, data, count);
> +
> +	return -EINVAL;
> +}
> +
> +static const struct typec_altmode_ops cros_typec_altmode_ops = {
> +	.enter = cros_typec_altmode_enter,
> +	.exit = cros_typec_altmode_exit,
> +	.vdm = cros_typec_altmode_vdm,
> +};
> +
> +#if IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
> +int cros_typec_displayport_status_update(struct typec_altmode *altmode,
> +					 struct typec_displayport_data *data)
> +{
> +	struct cros_typec_altmode_data *adata =
> +		typec_altmode_get_drvdata(altmode);
> +
> +	if (!adata->am_data.dp.pending_status_update) {
> +		dev_dbg(&altmode->dev,
> +			"Got DPStatus without a pending request");
> +		return 0;
> +	}
> +
> +	if (adata->am_data.dp.configured && adata->am_data.dp.data.conf != data->conf)
> +		dev_dbg(&altmode->dev,
> +			"DP Conf doesn't match. Requested 0x%04x, Actual 0x%04x",
> +			adata->am_data.dp.data.conf, data->conf);
> +
> +	adata->am_data.dp.data = *data;
> +	adata->am_data.dp.pending_status_update = false;
> +	adata->header |= VDO_CMDT(CMDT_RSP_ACK);
> +	adata->vdo_data = &adata->am_data.dp.data.status;
> +	adata->vdo_size = 2;
> +
> +	schedule_work(&adata->work);
> +	return 0;
> +}
> +
> +struct typec_altmode *
> +cros_typec_register_displayport(struct cros_typec_port *port,
> +				struct typec_altmode_desc *desc,
> +				bool ap_mode_entry)
> +{
> +	struct typec_altmode *alt;
> +	struct cros_typec_altmode_data *data;
> +
> +	alt = typec_port_register_altmode(port->port, desc);
> +	if (IS_ERR(alt))
> +		return alt;
> +
> +	data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data) {
> +		typec_unregister_altmode(alt);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	INIT_WORK(&data->work, cros_typec_altmode_work);
> +	data->alt = alt;
> +	data->port = port;
> +	data->ap_mode_entry = ap_mode_entry;
> +	data->sid = USB_TYPEC_DP_SID;
> +	data->mode = USB_TYPEC_DP_MODE;
> +
> +	data->am_data.dp.configured = false;
> +	typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
> +	typec_altmode_set_drvdata(alt, data);
> +
> +	return alt;
> +}
> +#endif
> diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
> new file mode 100644
> index 000000000000..c6f8fb02c99c
> --- /dev/null
> +++ b/drivers/platform/chrome/cros_typec_altmode.h
> @@ -0,0 +1,34 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef __CROS_TYPEC_ALTMODE_H__
> +#define __CROS_TYPEC_ALTMODE_H__
> +
> +struct cros_typec_port;
> +struct typec_altmode;
> +struct typec_altmode_desc;
> +struct typec_displayport_data;
> +
> +#if IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
> +struct typec_altmode *
> +cros_typec_register_displayport(struct cros_typec_port *port,
> +				struct typec_altmode_desc *desc,
> +				bool ap_mode_entry);
> +
> +int cros_typec_displayport_status_update(struct typec_altmode *altmode,
> +					 struct typec_displayport_data *data);
> +#else
> +static inline struct typec_altmode *
> +cros_typec_register_displayport(struct cros_typec_port *port,
> +				struct typec_altmode_desc *desc,
> +				bool ap_mode_entry)
> +{
> +	return typec_port_register_altmode(port->port, desc);
> +}
> +
> +static inline int cros_typec_displayport_status_update(struct typec_altmode *altmode,
> +					 struct typec_displayport_data *data)
> +{
> +	return 0;
> +}
> +#endif
> +#endif /* __CROS_TYPEC_ALTMODE_H__ */
> -- 
> 2.47.0.163.g1226f6d8fa-goog
>
kernel test robot Oct. 31, 2024, 7:43 p.m. UTC | #3
Hi Abhishek,

kernel test robot noticed the following build warnings:

[auto build test WARNING on chrome-platform/for-next]
[also build test WARNING on chrome-platform/for-firmware-next usb/usb-testing usb/usb-next usb/usb-linus westeri-thunderbolt/next linus/master v6.12-rc5 next-20241031]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Abhishek-Pandit-Subedi/usb-typec-Add-driver-for-Thunderbolt-3-Alternate-Mode/20241031-053304
base:   https://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux.git for-next
patch link:    https://lore.kernel.org/r/20241030142833.v2.5.I142fc0c09df58689b98f0cebf1c5e48b9d4fa800%40changeid
patch subject: [PATCH v2 5/7] platform/chrome: cros_ec_typec: Displayport support
config: arm-multi_v7_defconfig (https://download.01.org/0day-ci/archive/20241101/202411010346.AqbfMqLc-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 13.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241101/202411010346.AqbfMqLc-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411010346.AqbfMqLc-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/platform/chrome/cros_typec_altmode.c:212:39: warning: 'cros_typec_altmode_ops' defined but not used [-Wunused-const-variable=]
     212 | static const struct typec_altmode_ops cros_typec_altmode_ops = {
         |                                       ^~~~~~~~~~~~~~~~~~~~~~
>> drivers/platform/chrome/cros_typec_altmode.c:40:13: warning: 'cros_typec_altmode_work' defined but not used [-Wunused-function]
      40 | static void cros_typec_altmode_work(struct work_struct *work)
         |             ^~~~~~~~~~~~~~~~~~~~~~~


vim +/cros_typec_altmode_ops +212 drivers/platform/chrome/cros_typec_altmode.c

    39	
  > 40	static void cros_typec_altmode_work(struct work_struct *work)
    41	{
    42		struct cros_typec_altmode_data *data =
    43			container_of(work, struct cros_typec_altmode_data, work);
    44	
    45		if (typec_altmode_vdm(data->alt, data->header, data->vdo_data,
    46				      data->vdo_size))
    47			dev_err(&data->alt->dev, "VDM 0x%x failed", data->header);
    48	
    49		data->header = 0;
    50		data->vdo_data = NULL;
    51		data->vdo_size = 0;
    52	}
    53	
    54	static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
    55	{
    56		struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
    57		struct ec_params_typec_control req = {
    58			.port = data->port->port_num,
    59			.command = TYPEC_CONTROL_COMMAND_ENTER_MODE,
    60		};
    61		int svdm_version;
    62		int ret;
    63	
    64		if (!data->ap_mode_entry) {
    65			const struct typec_altmode *partner =
    66				typec_altmode_get_partner(alt);
    67			dev_warn(&partner->dev,
    68				 "EC does not support ap driven mode entry\n");
    69			return -EOPNOTSUPP;
    70		}
    71	
    72		if (data->sid == USB_TYPEC_DP_SID)
    73			req.mode_to_enter = CROS_EC_ALTMODE_DP;
    74		else
    75			return -EOPNOTSUPP;
    76	
    77		ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
    78				  &req, sizeof(req), NULL, 0);
    79		if (ret < 0)
    80			return ret;
    81	
    82		svdm_version = typec_altmode_get_svdm_version(alt);
    83		if (svdm_version < 0)
    84			return svdm_version;
    85	
    86		data->header = VDO(data->sid, 1, svdm_version, CMD_ENTER_MODE);
    87		data->header |= VDO_OPOS(data->mode);
    88		data->header |= VDO_CMDT(CMDT_RSP_ACK);
    89	
    90		data->vdo_data = NULL;
    91		data->vdo_size = 1;
    92	
    93		schedule_work(&data->work);
    94	
    95		return ret;
    96	}
    97	
    98	static int cros_typec_altmode_exit(struct typec_altmode *alt)
    99	{
   100		struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
   101		struct ec_params_typec_control req = {
   102			.port = data->port->port_num,
   103			.command = TYPEC_CONTROL_COMMAND_EXIT_MODES,
   104		};
   105		int svdm_version;
   106		int ret;
   107	
   108		if (!data->ap_mode_entry) {
   109			const struct typec_altmode *partner =
   110				typec_altmode_get_partner(alt);
   111			dev_warn(&partner->dev,
   112				 "EC does not support ap driven mode entry\n");
   113			return -EOPNOTSUPP;
   114		}
   115	
   116		ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
   117				  &req, sizeof(req), NULL, 0);
   118	
   119		if (ret < 0)
   120			return ret;
   121	
   122		svdm_version = typec_altmode_get_svdm_version(alt);
   123		if (svdm_version < 0)
   124			return svdm_version;
   125	
   126		data->header = VDO(data->sid, 1, svdm_version, CMD_EXIT_MODE);
   127		data->header |= VDO_OPOS(data->mode);
   128		data->header |= VDO_CMDT(CMDT_RSP_ACK);
   129	
   130		data->vdo_data = NULL;
   131		data->vdo_size = 1;
   132	
   133		schedule_work(&data->work);
   134	
   135		return ret;
   136	}
   137	
   138	static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
   139					      const u32 *data, int count)
   140	{
   141		struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
   142	
   143		int cmd_type = PD_VDO_CMDT(header);
   144		int cmd = PD_VDO_CMD(header);
   145		int svdm_version;
   146	
   147		if (!adata->ap_mode_entry) {
   148			const struct typec_altmode *partner =
   149				typec_altmode_get_partner(alt);
   150			dev_warn(&partner->dev,
   151				 "EC does not support ap driven mode entry\n");
   152			return -EOPNOTSUPP;
   153		}
   154	
   155		svdm_version = typec_altmode_get_svdm_version(alt);
   156		if (svdm_version < 0)
   157			return svdm_version;
   158	
   159		switch (cmd_type) {
   160		case CMDT_INIT:
   161			if (PD_VDO_SVDM_VER(header) < svdm_version) {
   162				typec_partner_set_svdm_version(adata->port->partner,
   163							       PD_VDO_SVDM_VER(header));
   164				svdm_version = PD_VDO_SVDM_VER(header);
   165			}
   166	
   167			adata->header = VDO(adata->sid, 1, svdm_version, cmd);
   168			adata->header |= VDO_OPOS(adata->mode);
   169	
   170			/*
   171			 * DP_CMD_CONFIGURE: We can't actually do anything with the
   172			 * provided VDO yet so just send back an ACK.
   173			 *
   174			 * DP_CMD_STATUS_UPDATE: We wait for Mux changes to send
   175			 * DPStatus Acks.
   176			 */
   177			switch (cmd) {
   178			case DP_CMD_CONFIGURE:
   179				adata->am_data.dp.data.conf = *data;
   180				adata->header |= VDO_CMDT(CMDT_RSP_ACK);
   181				adata->am_data.dp.configured = true;
   182				schedule_work(&adata->work);
   183				break;
   184			case DP_CMD_STATUS_UPDATE:
   185				adata->am_data.dp.pending_status_update = true;
   186				break;
   187			default:
   188				adata->header |= VDO_CMDT(CMDT_RSP_ACK);
   189				schedule_work(&adata->work);
   190				break;
   191			}
   192	
   193			break;
   194		default:
   195			break;
   196		}
   197	
   198		return 0;
   199	}
   200	
   201	static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
   202					      const u32 *data, int count)
   203	{
   204		struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
   205	
   206		if (adata->sid == USB_TYPEC_DP_SID)
   207			return cros_typec_displayport_vdm(alt, header, data, count);
   208	
   209		return -EINVAL;
   210	}
   211	
 > 212	static const struct typec_altmode_ops cros_typec_altmode_ops = {
   213		.enter = cros_typec_altmode_enter,
   214		.exit = cros_typec_altmode_exit,
   215		.vdm = cros_typec_altmode_vdm,
   216	};
   217
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e9659a5a7fb3..de99bcbda7d4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5369,9 +5369,12 @@  F:	include/linux/platform_data/cros_usbpd_notify.h
 
 CHROMEOS EC USB TYPE-C DRIVER
 M:	Prashant Malani <pmalani@chromium.org>
+M:	Benson Leung <bleung@chromium.org>
+M:	Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
 L:	chrome-platform@lists.linux.dev
 S:	Maintained
 F:	drivers/platform/chrome/cros_ec_typec.*
+F:	drivers/platform/chrome/cros_typec_altmode.*
 F:	drivers/platform/chrome/cros_typec_switch.c
 F:	drivers/platform/chrome/cros_typec_vdm.*
 
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 2dcc6ccc2302..8b007404c024 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -17,8 +17,9 @@  obj-$(CONFIG_CROS_EC_RPMSG)		+= cros_ec_rpmsg.o
 obj-$(CONFIG_CROS_EC_SPI)		+= cros_ec_spi.o
 obj-$(CONFIG_CROS_EC_UART)		+= cros_ec_uart.o
 cros_ec_lpcs-objs			:= cros_ec_lpc.o cros_ec_lpc_mec.o
-cros-ec-typec-objs			:= cros_ec_typec.o cros_typec_vdm.o
+cros-ec-typec-objs			:= cros_ec_typec.o cros_typec_vdm.o cros_typec_altmode.o
 obj-$(CONFIG_CROS_EC_TYPEC)		+= cros-ec-typec.o
+
 obj-$(CONFIG_CROS_EC_LPC)		+= cros_ec_lpcs.o
 obj-$(CONFIG_CROS_EC_PROTO)		+= cros_ec_proto.o cros_ec_trace.o
 obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT)	+= cros_kbd_led_backlight.o
diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
index 0c8db11bd8a4..7997e7136c4c 100644
--- a/drivers/platform/chrome/cros_ec_typec.c
+++ b/drivers/platform/chrome/cros_ec_typec.c
@@ -18,6 +18,7 @@ 
 
 #include "cros_ec_typec.h"
 #include "cros_typec_vdm.h"
+#include "cros_typec_altmode.h"
 
 #define DRV_NAME "cros-ec-typec"
 
@@ -293,12 +294,16 @@  static int cros_typec_register_port_altmodes(struct cros_typec_data *typec,
 	desc.svid = USB_TYPEC_DP_SID;
 	desc.mode = USB_TYPEC_DP_MODE;
 	desc.vdo = DP_PORT_VDO;
-	amode = typec_port_register_altmode(port->port, &desc);
+	amode = cros_typec_register_displayport(port, &desc,
+						typec->ap_driven_altmode);
 	if (IS_ERR(amode))
 		return PTR_ERR(amode);
 	port->port_altmode[CROS_EC_ALTMODE_DP] = amode;
+
+#if !IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
 	typec_altmode_set_drvdata(amode, port);
 	amode->ops = &port_amode_ops;
+#endif
 
 	/*
 	 * Register TBT compatibility alt mode. The EC will not enter the mode
@@ -575,6 +580,10 @@  static int cros_typec_enable_dp(struct cros_typec_data *typec,
 	if (!ret)
 		ret = typec_mux_set(port->mux, &port->state);
 
+	if (!ret)
+		cros_typec_displayport_status_update(port->state.alt,
+						     port->state.data);
+
 	return ret;
 }
 
@@ -1254,6 +1263,8 @@  static int cros_typec_probe(struct platform_device *pdev)
 
 	typec->typec_cmd_supported = cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_CMD);
 	typec->needs_mux_ack = cros_ec_check_features(ec_dev, EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);
+	typec->ap_driven_altmode = cros_ec_check_features(
+		ec_dev, EC_FEATURE_TYPEC_REQUIRE_AP_MODE_ENTRY);
 
 	ret = cros_ec_cmd(typec->ec, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
 			  &resp, sizeof(resp));
diff --git a/drivers/platform/chrome/cros_ec_typec.h b/drivers/platform/chrome/cros_ec_typec.h
index deda180a646f..9fd5342bb0ad 100644
--- a/drivers/platform/chrome/cros_ec_typec.h
+++ b/drivers/platform/chrome/cros_ec_typec.h
@@ -39,6 +39,7 @@  struct cros_typec_data {
 	struct work_struct port_work;
 	bool typec_cmd_supported;
 	bool needs_mux_ack;
+	bool ap_driven_altmode;
 };
 
 /* Per port data. */
diff --git a/drivers/platform/chrome/cros_typec_altmode.c b/drivers/platform/chrome/cros_typec_altmode.c
new file mode 100644
index 000000000000..af2f077674f1
--- /dev/null
+++ b/drivers/platform/chrome/cros_typec_altmode.c
@@ -0,0 +1,277 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Alt-mode implementation on ChromeOS EC.
+ *
+ * Copyright 2024 Google LLC
+ * Author: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
+ */
+#include "cros_ec_typec.h"
+
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/pd_vdo.h>
+
+#include "cros_typec_altmode.h"
+
+struct cros_typec_dp_data {
+	struct typec_displayport_data data;
+
+	bool configured;
+	bool pending_status_update;
+};
+
+struct cros_typec_altmode_data {
+	struct work_struct work;
+	struct cros_typec_port *port;
+	struct typec_altmode *alt;
+	bool ap_mode_entry;
+
+	u32 header;
+	u32 *vdo_data;
+	u8 vdo_size;
+
+	u16 sid;
+	u8 mode;
+
+	union am_specific {
+		struct cros_typec_dp_data dp;
+	} am_data;
+};
+
+static void cros_typec_altmode_work(struct work_struct *work)
+{
+	struct cros_typec_altmode_data *data =
+		container_of(work, struct cros_typec_altmode_data, work);
+
+	if (typec_altmode_vdm(data->alt, data->header, data->vdo_data,
+			      data->vdo_size))
+		dev_err(&data->alt->dev, "VDM 0x%x failed", data->header);
+
+	data->header = 0;
+	data->vdo_data = NULL;
+	data->vdo_size = 0;
+}
+
+static int cros_typec_altmode_enter(struct typec_altmode *alt, u32 *vdo)
+{
+	struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
+	struct ec_params_typec_control req = {
+		.port = data->port->port_num,
+		.command = TYPEC_CONTROL_COMMAND_ENTER_MODE,
+	};
+	int svdm_version;
+	int ret;
+
+	if (!data->ap_mode_entry) {
+		const struct typec_altmode *partner =
+			typec_altmode_get_partner(alt);
+		dev_warn(&partner->dev,
+			 "EC does not support ap driven mode entry\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (data->sid == USB_TYPEC_DP_SID)
+		req.mode_to_enter = CROS_EC_ALTMODE_DP;
+	else
+		return -EOPNOTSUPP;
+
+	ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
+			  &req, sizeof(req), NULL, 0);
+	if (ret < 0)
+		return ret;
+
+	svdm_version = typec_altmode_get_svdm_version(alt);
+	if (svdm_version < 0)
+		return svdm_version;
+
+	data->header = VDO(data->sid, 1, svdm_version, CMD_ENTER_MODE);
+	data->header |= VDO_OPOS(data->mode);
+	data->header |= VDO_CMDT(CMDT_RSP_ACK);
+
+	data->vdo_data = NULL;
+	data->vdo_size = 1;
+
+	schedule_work(&data->work);
+
+	return ret;
+}
+
+static int cros_typec_altmode_exit(struct typec_altmode *alt)
+{
+	struct cros_typec_altmode_data *data = typec_altmode_get_drvdata(alt);
+	struct ec_params_typec_control req = {
+		.port = data->port->port_num,
+		.command = TYPEC_CONTROL_COMMAND_EXIT_MODES,
+	};
+	int svdm_version;
+	int ret;
+
+	if (!data->ap_mode_entry) {
+		const struct typec_altmode *partner =
+			typec_altmode_get_partner(alt);
+		dev_warn(&partner->dev,
+			 "EC does not support ap driven mode entry\n");
+		return -EOPNOTSUPP;
+	}
+
+	ret = cros_ec_cmd(data->port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL,
+			  &req, sizeof(req), NULL, 0);
+
+	if (ret < 0)
+		return ret;
+
+	svdm_version = typec_altmode_get_svdm_version(alt);
+	if (svdm_version < 0)
+		return svdm_version;
+
+	data->header = VDO(data->sid, 1, svdm_version, CMD_EXIT_MODE);
+	data->header |= VDO_OPOS(data->mode);
+	data->header |= VDO_CMDT(CMDT_RSP_ACK);
+
+	data->vdo_data = NULL;
+	data->vdo_size = 1;
+
+	schedule_work(&data->work);
+
+	return ret;
+}
+
+static int cros_typec_displayport_vdm(struct typec_altmode *alt, u32 header,
+				      const u32 *data, int count)
+{
+	struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
+
+	int cmd_type = PD_VDO_CMDT(header);
+	int cmd = PD_VDO_CMD(header);
+	int svdm_version;
+
+	if (!adata->ap_mode_entry) {
+		const struct typec_altmode *partner =
+			typec_altmode_get_partner(alt);
+		dev_warn(&partner->dev,
+			 "EC does not support ap driven mode entry\n");
+		return -EOPNOTSUPP;
+	}
+
+	svdm_version = typec_altmode_get_svdm_version(alt);
+	if (svdm_version < 0)
+		return svdm_version;
+
+	switch (cmd_type) {
+	case CMDT_INIT:
+		if (PD_VDO_SVDM_VER(header) < svdm_version) {
+			typec_partner_set_svdm_version(adata->port->partner,
+						       PD_VDO_SVDM_VER(header));
+			svdm_version = PD_VDO_SVDM_VER(header);
+		}
+
+		adata->header = VDO(adata->sid, 1, svdm_version, cmd);
+		adata->header |= VDO_OPOS(adata->mode);
+
+		/*
+		 * DP_CMD_CONFIGURE: We can't actually do anything with the
+		 * provided VDO yet so just send back an ACK.
+		 *
+		 * DP_CMD_STATUS_UPDATE: We wait for Mux changes to send
+		 * DPStatus Acks.
+		 */
+		switch (cmd) {
+		case DP_CMD_CONFIGURE:
+			adata->am_data.dp.data.conf = *data;
+			adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+			adata->am_data.dp.configured = true;
+			schedule_work(&adata->work);
+			break;
+		case DP_CMD_STATUS_UPDATE:
+			adata->am_data.dp.pending_status_update = true;
+			break;
+		default:
+			adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+			schedule_work(&adata->work);
+			break;
+		}
+
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int cros_typec_altmode_vdm(struct typec_altmode *alt, u32 header,
+				      const u32 *data, int count)
+{
+	struct cros_typec_altmode_data *adata = typec_altmode_get_drvdata(alt);
+
+	if (adata->sid == USB_TYPEC_DP_SID)
+		return cros_typec_displayport_vdm(alt, header, data, count);
+
+	return -EINVAL;
+}
+
+static const struct typec_altmode_ops cros_typec_altmode_ops = {
+	.enter = cros_typec_altmode_enter,
+	.exit = cros_typec_altmode_exit,
+	.vdm = cros_typec_altmode_vdm,
+};
+
+#if IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
+int cros_typec_displayport_status_update(struct typec_altmode *altmode,
+					 struct typec_displayport_data *data)
+{
+	struct cros_typec_altmode_data *adata =
+		typec_altmode_get_drvdata(altmode);
+
+	if (!adata->am_data.dp.pending_status_update) {
+		dev_dbg(&altmode->dev,
+			"Got DPStatus without a pending request");
+		return 0;
+	}
+
+	if (adata->am_data.dp.configured && adata->am_data.dp.data.conf != data->conf)
+		dev_dbg(&altmode->dev,
+			"DP Conf doesn't match. Requested 0x%04x, Actual 0x%04x",
+			adata->am_data.dp.data.conf, data->conf);
+
+	adata->am_data.dp.data = *data;
+	adata->am_data.dp.pending_status_update = false;
+	adata->header |= VDO_CMDT(CMDT_RSP_ACK);
+	adata->vdo_data = &adata->am_data.dp.data.status;
+	adata->vdo_size = 2;
+
+	schedule_work(&adata->work);
+	return 0;
+}
+
+struct typec_altmode *
+cros_typec_register_displayport(struct cros_typec_port *port,
+				struct typec_altmode_desc *desc,
+				bool ap_mode_entry)
+{
+	struct typec_altmode *alt;
+	struct cros_typec_altmode_data *data;
+
+	alt = typec_port_register_altmode(port->port, desc);
+	if (IS_ERR(alt))
+		return alt;
+
+	data = devm_kzalloc(&alt->dev, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		typec_unregister_altmode(alt);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	INIT_WORK(&data->work, cros_typec_altmode_work);
+	data->alt = alt;
+	data->port = port;
+	data->ap_mode_entry = ap_mode_entry;
+	data->sid = USB_TYPEC_DP_SID;
+	data->mode = USB_TYPEC_DP_MODE;
+
+	data->am_data.dp.configured = false;
+	typec_altmode_set_ops(alt, &cros_typec_altmode_ops);
+	typec_altmode_set_drvdata(alt, data);
+
+	return alt;
+}
+#endif
diff --git a/drivers/platform/chrome/cros_typec_altmode.h b/drivers/platform/chrome/cros_typec_altmode.h
new file mode 100644
index 000000000000..c6f8fb02c99c
--- /dev/null
+++ b/drivers/platform/chrome/cros_typec_altmode.h
@@ -0,0 +1,34 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __CROS_TYPEC_ALTMODE_H__
+#define __CROS_TYPEC_ALTMODE_H__
+
+struct cros_typec_port;
+struct typec_altmode;
+struct typec_altmode_desc;
+struct typec_displayport_data;
+
+#if IS_ENABLED(CONFIG_TYPEC_DP_ALTMODE)
+struct typec_altmode *
+cros_typec_register_displayport(struct cros_typec_port *port,
+				struct typec_altmode_desc *desc,
+				bool ap_mode_entry);
+
+int cros_typec_displayport_status_update(struct typec_altmode *altmode,
+					 struct typec_displayport_data *data);
+#else
+static inline struct typec_altmode *
+cros_typec_register_displayport(struct cros_typec_port *port,
+				struct typec_altmode_desc *desc,
+				bool ap_mode_entry)
+{
+	return typec_port_register_altmode(port->port, desc);
+}
+
+static inline int cros_typec_displayport_status_update(struct typec_altmode *altmode,
+					 struct typec_displayport_data *data)
+{
+	return 0;
+}
+#endif
+#endif /* __CROS_TYPEC_ALTMODE_H__ */