cros_typec_vdm.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * USB Power Delivery Vendor Defined Message (VDM) support code.
  4 *
  5 * Copyright 2023 Google LLC
  6 * Author: Prashant Malani <pmalani@chromium.org>
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/platform_data/cros_ec_commands.h>
 11#include <linux/usb/pd_vdo.h>
 12
 13#include "cros_ec_typec.h"
 14#include "cros_typec_vdm.h"
 15
 16/*
 17 * Retrieves pending VDM attention messages from the EC and forwards them to the altmode driver
 18 * based on SVID.
 19 */
 20void cros_typec_handle_vdm_attention(struct cros_typec_data *typec, int port_num)
 21{
 22	struct ec_response_typec_vdm_response resp;
 23	struct ec_params_typec_vdm_response req = {
 24		.port = port_num,
 25	};
 26	struct typec_altmode *amode;
 27	u16 svid;
 28	u32 hdr;
 29	int ret;
 30
 31	do {
 32		ret = cros_ec_cmd(typec->ec, 0, EC_CMD_TYPEC_VDM_RESPONSE, &req,
 33				sizeof(req), &resp, sizeof(resp));
 34		if (ret < 0) {
 35			dev_warn(typec->dev, "Failed VDM response fetch, port: %d\n", port_num);
 36			return;
 37		}
 38
 39		hdr = resp.vdm_response[0];
 40		svid = PD_VDO_VID(hdr);
 41		dev_dbg(typec->dev, "Received VDM Attention header: %x, port: %d\n", hdr, port_num);
 42
 43		amode = typec_match_altmode(typec->ports[port_num]->port_altmode,
 44					    CROS_EC_ALTMODE_MAX, svid, PD_VDO_OPOS(hdr));
 45		if (!amode) {
 46			dev_err(typec->dev,
 47				"Received VDM for unregistered altmode (SVID:%x), port: %d\n",
 48				svid, port_num);
 49			return;
 50		}
 51
 52		typec_altmode_attention(amode, resp.vdm_attention[1]);
 53	} while (resp.vdm_attention_left);
 54}
 55
 56/*
 57 * Retrieves a VDM response from the EC and forwards it to the altmode driver based on SVID.
 58 */
 59void cros_typec_handle_vdm_response(struct cros_typec_data *typec, int port_num)
 60{
 61	struct ec_response_typec_vdm_response resp;
 62	struct ec_params_typec_vdm_response req = {
 63		.port = port_num,
 64	};
 65	struct typec_altmode *amode;
 66	u16 svid;
 67	u32 hdr;
 68	int ret;
 69
 70	ret = cros_ec_cmd(typec->ec, 0, EC_CMD_TYPEC_VDM_RESPONSE, &req,
 71			  sizeof(req), &resp, sizeof(resp));
 72	if (ret < 0) {
 73		dev_warn(typec->dev, "Failed VDM response fetch, port: %d\n", port_num);
 74		return;
 75	}
 76
 77	hdr = resp.vdm_response[0];
 78	svid = PD_VDO_VID(hdr);
 79	dev_dbg(typec->dev, "Received VDM header: %x, port: %d\n", hdr, port_num);
 80
 81	amode = typec_match_altmode(typec->ports[port_num]->port_altmode, CROS_EC_ALTMODE_MAX,
 82				    svid, PD_VDO_OPOS(hdr));
 83	if (!amode) {
 84		dev_err(typec->dev, "Received VDM for unregistered altmode (SVID:%x), port: %d\n",
 85			svid, port_num);
 86		return;
 87	}
 88
 89	ret = typec_altmode_vdm(amode, hdr, &resp.vdm_response[1], resp.vdm_data_objects);
 90	if (ret)
 91		dev_err(typec->dev, "Failed to forward VDM to altmode (SVID:%x), port: %d\n",
 92			svid, port_num);
 93}
 94
 95static int cros_typec_port_amode_enter(struct typec_altmode *amode, u32 *vdo)
 96{
 97	struct cros_typec_port *port = typec_altmode_get_drvdata(amode);
 98	struct ec_params_typec_control req = {
 99		.port = port->port_num,
100		.command = TYPEC_CONTROL_COMMAND_SEND_VDM_REQ,
101	};
102	struct typec_vdm_req vdm_req = {};
103	u32 hdr;
104
105	hdr = VDO(amode->svid, 1, SVDM_VER_2_0, CMD_ENTER_MODE);
106	hdr |= VDO_OPOS(amode->mode);
107
108	vdm_req.vdm_data[0] = hdr;
109	vdm_req.vdm_data_objects = 1;
110	vdm_req.partner_type = TYPEC_PARTNER_SOP;
111	req.vdm_req_params = vdm_req;
112
113	dev_dbg(port->typec_data->dev, "Sending EnterMode VDM, hdr: %x, port: %d\n",
114		hdr, port->port_num);
115
116	return cros_ec_cmd(port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
117			   sizeof(req), NULL, 0);
118}
119
120static int cros_typec_port_amode_vdm(struct typec_altmode *amode, const u32 hdr,
121				     const u32 *vdo, int cnt)
122{
123	struct cros_typec_port *port = typec_altmode_get_drvdata(amode);
124	struct ec_params_typec_control req = {
125		.port = port->port_num,
126		.command = TYPEC_CONTROL_COMMAND_SEND_VDM_REQ,
127	};
128	struct typec_vdm_req vdm_req = {};
129	int i;
130
131	vdm_req.vdm_data[0] = hdr;
132	vdm_req.vdm_data_objects = cnt;
133	for (i = 1; i < cnt; i++)
134		vdm_req.vdm_data[i] = vdo[i-1];
135	vdm_req.partner_type = TYPEC_PARTNER_SOP;
136	req.vdm_req_params = vdm_req;
137
138	dev_dbg(port->typec_data->dev, "Sending VDM, hdr: %x, num_objects: %d, port: %d\n",
139		hdr, cnt, port->port_num);
140
141	return cros_ec_cmd(port->typec_data->ec, 0, EC_CMD_TYPEC_CONTROL, &req,
142			   sizeof(req), NULL, 0);
143}
144
145const struct typec_altmode_ops port_amode_ops = {
146	.enter = cros_typec_port_amode_enter,
147	.vdm = cros_typec_port_amode_vdm,
148};