diff options
Diffstat (limited to 'drivers/platform/chrome/cros_typec_switch.c')
-rw-r--r-- | drivers/platform/chrome/cros_typec_switch.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c new file mode 100644 index 0000000000..0eefdcf14d --- /dev/null +++ b/drivers/platform/chrome/cros_typec_switch.c @@ -0,0 +1,329 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2022 Google LLC + * + * This driver provides the ability to configure Type-C muxes and retimers which are controlled by + * the ChromeOS EC. + */ + +#include <linux/acpi.h> +#include <linux/delay.h> +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/platform_device.h> +#include <linux/usb/typec_altmode.h> +#include <linux/usb/typec_dp.h> +#include <linux/usb/typec_mux.h> +#include <linux/usb/typec_retimer.h> + +/* Handles and other relevant data required for each port's switches. */ +struct cros_typec_port { + int port_num; + struct typec_mux_dev *mode_switch; + struct typec_retimer *retimer; + struct cros_typec_switch_data *sdata; +}; + +/* Driver-specific data. */ +struct cros_typec_switch_data { + struct device *dev; + struct cros_ec_device *ec; + struct cros_typec_port *ports[EC_USB_PD_MAX_PORTS]; +}; + +static int cros_typec_cmd_mux_set(struct cros_typec_switch_data *sdata, int port_num, u8 index, + u8 state) +{ + struct ec_params_typec_control req = { + .port = port_num, + .command = TYPEC_CONTROL_COMMAND_USB_MUX_SET, + .mux_params = { + .mux_index = index, + .mux_flags = state, + }, + }; + + return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req, sizeof(req), NULL, 0); +} + +static int cros_typec_get_mux_state(unsigned long mode, struct typec_altmode *alt) +{ + int ret = -EOPNOTSUPP; + u8 pin_assign; + + if (mode == TYPEC_STATE_SAFE) { + ret = USB_PD_MUX_SAFE_MODE; + } else if (mode == TYPEC_STATE_USB) { + ret = USB_PD_MUX_USB_ENABLED; + } else if (alt && alt->svid == USB_TYPEC_DP_SID) { + ret = USB_PD_MUX_DP_ENABLED; + pin_assign = mode - TYPEC_STATE_MODAL; + if (pin_assign & DP_PIN_ASSIGN_D) + ret |= USB_PD_MUX_USB_ENABLED; + } + + return ret; +} + +static int cros_typec_send_clear_event(struct cros_typec_switch_data *sdata, int port_num, + u32 events_mask) +{ + struct ec_params_typec_control req = { + .port = port_num, + .command = TYPEC_CONTROL_COMMAND_CLEAR_EVENTS, + .clear_events_mask = events_mask, + }; + + return cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_CONTROL, &req, sizeof(req), NULL, 0); +} + +static bool cros_typec_check_event(struct cros_typec_switch_data *sdata, int port_num, u32 mask) +{ + struct ec_response_typec_status resp; + struct ec_params_typec_status req = { + .port = port_num, + }; + int ret; + + ret = cros_ec_cmd(sdata->ec, 0, EC_CMD_TYPEC_STATUS, &req, sizeof(req), + &resp, sizeof(resp)); + if (ret < 0) { + dev_warn(sdata->dev, "EC_CMD_TYPEC_STATUS failed for port: %d\n", port_num); + return false; + } + + if (resp.events & mask) + return true; + + return false; +} + +/* + * The ChromeOS EC treats both mode-switches and retimers as "muxes" for the purposes of the + * host command API. This common function configures and verifies the retimer/mode-switch + * according to the provided setting. + */ +static int cros_typec_configure_mux(struct cros_typec_switch_data *sdata, int port_num, int index, + unsigned long mode, struct typec_altmode *alt) +{ + unsigned long end; + u32 event_mask; + u8 mux_state; + int ret; + + ret = cros_typec_get_mux_state(mode, alt); + if (ret < 0) + return ret; + mux_state = (u8)ret; + + /* Clear any old mux set done event. */ + if (index == 0) + event_mask = PD_STATUS_EVENT_MUX_0_SET_DONE; + else + event_mask = PD_STATUS_EVENT_MUX_1_SET_DONE; + + ret = cros_typec_send_clear_event(sdata, port_num, event_mask); + if (ret < 0) + return ret; + + /* Send the set command. */ + ret = cros_typec_cmd_mux_set(sdata, port_num, index, mux_state); + if (ret < 0) + return ret; + + /* Check for the mux set done event. */ + end = jiffies + msecs_to_jiffies(1000); + do { + if (cros_typec_check_event(sdata, port_num, event_mask)) + return 0; + + usleep_range(500, 1000); + } while (time_before(jiffies, end)); + + dev_err(sdata->dev, "Timed out waiting for mux set done on index: %d, state: %d\n", + index, mux_state); + + return -ETIMEDOUT; +} + +static int cros_typec_mode_switch_set(struct typec_mux_dev *mode_switch, + struct typec_mux_state *state) +{ + struct cros_typec_port *port = typec_mux_get_drvdata(mode_switch); + + /* Mode switches have index 0. */ + return cros_typec_configure_mux(port->sdata, port->port_num, 0, state->mode, state->alt); +} + +static int cros_typec_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state) +{ + struct cros_typec_port *port = typec_retimer_get_drvdata(retimer); + + /* Retimers have index 1. */ + return cros_typec_configure_mux(port->sdata, port->port_num, 1, state->mode, state->alt); +} + +static void cros_typec_unregister_switches(struct cros_typec_switch_data *sdata) +{ + int i; + + for (i = 0; i < EC_USB_PD_MAX_PORTS; i++) { + if (!sdata->ports[i]) + continue; + typec_retimer_unregister(sdata->ports[i]->retimer); + typec_mux_unregister(sdata->ports[i]->mode_switch); + } +} + +static int cros_typec_register_mode_switch(struct cros_typec_port *port, + struct fwnode_handle *fwnode) +{ + struct typec_mux_desc mode_switch_desc = { + .fwnode = fwnode, + .drvdata = port, + .name = fwnode_get_name(fwnode), + .set = cros_typec_mode_switch_set, + }; + + port->mode_switch = typec_mux_register(port->sdata->dev, &mode_switch_desc); + + return PTR_ERR_OR_ZERO(port->mode_switch); +} + +static int cros_typec_register_retimer(struct cros_typec_port *port, struct fwnode_handle *fwnode) +{ + struct typec_retimer_desc retimer_desc = { + .fwnode = fwnode, + .drvdata = port, + .name = fwnode_get_name(fwnode), + .set = cros_typec_retimer_set, + }; + + port->retimer = typec_retimer_register(port->sdata->dev, &retimer_desc); + + return PTR_ERR_OR_ZERO(port->retimer); +} + +static int cros_typec_register_switches(struct cros_typec_switch_data *sdata) +{ + struct cros_typec_port *port; + struct device *dev = sdata->dev; + struct fwnode_handle *fwnode; + struct acpi_device *adev; + unsigned long long index; + int nports, ret; + + nports = device_get_child_node_count(dev); + if (nports == 0) { + dev_err(dev, "No switch devices found.\n"); + return -ENODEV; + } + + device_for_each_child_node(dev, fwnode) { + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL); + if (!port) { + ret = -ENOMEM; + goto err_switch; + } + + adev = to_acpi_device_node(fwnode); + if (!adev) { + dev_err(fwnode->dev, "Couldn't get ACPI device handle\n"); + ret = -ENODEV; + goto err_switch; + } + + ret = acpi_evaluate_integer(adev->handle, "_ADR", NULL, &index); + if (ACPI_FAILURE(ret)) { + dev_err(fwnode->dev, "_ADR wasn't evaluated\n"); + ret = -ENODATA; + goto err_switch; + } + + if (index >= EC_USB_PD_MAX_PORTS) { + dev_err(fwnode->dev, "Invalid port index number: %llu\n", index); + ret = -EINVAL; + goto err_switch; + } + port->sdata = sdata; + port->port_num = index; + sdata->ports[index] = port; + + if (fwnode_property_present(fwnode, "retimer-switch")) { + ret = cros_typec_register_retimer(port, fwnode); + if (ret) { + dev_err(dev, "Retimer switch register failed\n"); + goto err_switch; + } + + dev_dbg(dev, "Retimer switch registered for index %llu\n", index); + } + + if (!fwnode_property_present(fwnode, "mode-switch")) + continue; + + ret = cros_typec_register_mode_switch(port, fwnode); + if (ret) { + dev_err(dev, "Mode switch register failed\n"); + goto err_switch; + } + + dev_dbg(dev, "Mode switch registered for index %llu\n", index); + } + + return 0; +err_switch: + fwnode_handle_put(fwnode); + cros_typec_unregister_switches(sdata); + return ret; +} + +static int cros_typec_switch_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct cros_typec_switch_data *sdata; + + sdata = devm_kzalloc(dev, sizeof(*sdata), GFP_KERNEL); + if (!sdata) + return -ENOMEM; + + sdata->dev = dev; + sdata->ec = dev_get_drvdata(pdev->dev.parent); + + platform_set_drvdata(pdev, sdata); + + return cros_typec_register_switches(sdata); +} + +static int cros_typec_switch_remove(struct platform_device *pdev) +{ + struct cros_typec_switch_data *sdata = platform_get_drvdata(pdev); + + cros_typec_unregister_switches(sdata); + return 0; +} + +#ifdef CONFIG_ACPI +static const struct acpi_device_id cros_typec_switch_acpi_id[] = { + { "GOOG001A", 0 }, + {} +}; +MODULE_DEVICE_TABLE(acpi, cros_typec_switch_acpi_id); +#endif + +static struct platform_driver cros_typec_switch_driver = { + .driver = { + .name = "cros-typec-switch", + .acpi_match_table = ACPI_PTR(cros_typec_switch_acpi_id), + }, + .probe = cros_typec_switch_probe, + .remove = cros_typec_switch_remove, +}; + +module_platform_driver(cros_typec_switch_driver); + +MODULE_AUTHOR("Prashant Malani <pmalani@chromium.org>"); +MODULE_DESCRIPTION("ChromeOS EC Type-C Switch control"); +MODULE_LICENSE("GPL"); |