Change in coreboot[master]: soc/intel/common: Configure TCSS access through IOE P2SB

[Eric Lai (Code Review)]

Attention is currently required from: Subrata Banik, Tim Wawrzynczak, John Zhao, Paul Menzel, Angel Pons, Patrick Rudolph, EricR Lai.
Eric Lai has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/62723 )

Change subject: soc/intel/common: Configure TCSS access through IOE P2SB
......................................................................

Patch Set 5:

(1 comment)

File src/soc/intel/common/block/tcss/tcss.c:

https://review.coreboot.org/c/coreboot/+/62723/comment/124b61b2_c9e54cdb 
PS5, Line 371: static void ioe_tcss_configure_aux_bias_pads_sbi(
             : 	const struct typec_aux_bias_pads *pads)
             : {
             : 	for (size_t i = 0; i < MAX_TYPE_C_PORTS; i++) {
             : 		if (pads[i].pad_auxn_dc && pads[i].pad_auxp_dc) {
             : 			ioe_p2sb_sbi_write(PID_IOM, IOM_AUX_BIAS_CTRL_PULLUP_OFFSET(i),
             : 				calc_bias_ctrl_reg_value(pads[i].pad_auxp_dc));
             : 			ioe_p2sb_sbi_write(PID_IOM, IOM_AUX_BIAS_CTRL_PULLDOWN_OFFSET(i),
             : 				calc_bias_ctrl_reg_value(pads[i].pad_auxn_dc));
             : 		}
             : 	}
             : }
             : 
             : static void tcss_configure_aux_bias_pads(
             : 	const struct typec_aux_bias_pads *pads)
             : {
             : 	if (CONFIG(SOC_INTEL_COMMON_BLOCK_TCSS_REG_ACCESS_REGBAR))
             : 		tcss_configure_aux_bias_pads_regbar(pads);
             : 	else if (CONFIG(SOC_INTEL_COMMON_BLOCK_TCSS_REG_ACCESS_SBI)) {
             : 		if (CONFIG(SOC_INTEL_COMMON_BLOCK_IOE_P2SB))
             : 			ioe_tcss_configure_aux_bias_pads_sbi(pads);
             : 	}
             : 	else
             : 		printk(BIOS_ERR, "%s: Error: No TCSS configuration method is selected!\n",
             : 					__func__);
             : }
             : 
             : const struct tcss_port_map *tcss_get_port_info(size_t *num_ports)
             : {
             : 	static struct tcss_port_map port_map[MAX_TYPE_C_PORTS];
             : 	size_t active_ports = 0;
             : 	size_t port;
             : 
             : 	for (port = 0; port < MAX_TYPE_C_PORTS; port++) {
             : 		const struct device_path conn_path[] = {
             : 			{.type = DEVICE_PATH_PCI, .pci.devfn = PCH_DEVFN_PMC},
             : 			{.type = DEVICE_PATH_GENERIC, .generic.id = 0, .generic.subid = 0},
             : 			{.type = DEVICE_PATH_GENERIC, .generic.id = port},
             : 		};
             : 		const struct device *conn = find_dev_nested_path(pci_root_bus(), conn_path,
             : 								ARRAY_SIZE(conn_path));
             : 		unsigned int usb2_port, usb3_port;
             : 
             : 		if (!conn)
             : 			continue;
             : 
             : 		if (CONFIG(DRIVERS_INTEL_PMC) &&
             : 			intel_pmc_mux_conn_get_ports(conn, &usb2_port, &usb3_port)) {
             : 			port_map[active_ports].usb2_port = usb2_port;
             : 			port_map[active_ports].usb3_port = usb3_port;
             : 			++active_ports;
             : 		}
             : 	}
             : 
             : 	*num_ports = active_ports;
             : 	return port_map;
             : }
             : 
             : void tcss_configure(const struct typec_aux_bias_pads aux_bias_pads[MAX_TYPE_C_PORTS])
             : {
             : 	const struct tcss_port_map *port_map;
             : 	size_t num_ports;
             : 	size_t i;
             : 
             : 	port_map = tcss_get_port_info(&num_ports);
             : 	if (port_map == NULL)
             : 		return;
             : 
             : 	for (i = 0; i < num_ports; i++)
             : 		tcss_init_mux(i, &port_map[i]);
             : 
             : 	/* This should be performed before alternate modes are entered */
             : 	tcss_configure_aux_bias_pads(aux_bias_pads);
             : 
             : 	if (CONFIG(ENABLE_TCSS_DISPLAY_DETECTION))
             : 		tcss_configure_dp_mode(port_map, num_ports);
             : }
             : 
             : uint32_t tcss_valid_tbt_auth(void)
             : {
             : 	if (CONFIG(SOC_INTEL_COMMON_BLOCK_TCSS_REG_ACCESS_REGBAR)) {
             : 		return REGBAR32(PID_IOM, IOM_CSME_IMR_TBT_STATUS) & TBT_VALID_AUTHENTICATION;
             : 	} else if (CONFIG(SOC_INTEL_COMMON_BLOCK_TCSS_REG_ACCESS_SBI)) {
             : 		if (CONFIG(SOC_INTEL_COMMON_BLOCK_IOE_P2SB))
             : 			return (ioe_p2sb_sbi_read(PID_IOM, IOM_CSME_IMR_TBT_STATUS) &
             : 							TBT_VALID_AUTHENTICATION);
             : 	}
             : 
             : 	printk(BIOS_ERR, "%s: Error: No validation for Thunderbolt authentication!\n",
             : 					__func__);
             : 	return 0;
             : }
> This is getting to be pretty complex logic to pick which method is used to access TCSS registers her […]

I vote soc_tcss_ops. Very objective way like other chips driver.