From: Prashant Malani Date: Tue, 16 Aug 2022 21:48:30 +0000 (+0000) Subject: platform/chrome: cros_typec_switch: Add switch driver X-Git-Tag: v6.6.17~6496^2~16 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=affc804c44c8259ae53423aa3b5c20907e3a9a34;p=platform%2Fkernel%2Flinux-rpi.git platform/chrome: cros_typec_switch: Add switch driver Introduce a driver to configure USB Type-C mode switches and retimers which are controlled by the ChromeOS EC (Embedded Controller). This allows Type-C port drivers, as well as alternate mode drivers to configure their relevant mode switches and retimers according to the Type-C state they want to achieve. ACPI devices with ID GOOG001A will bind to this driver. Currently, we only register a retimer switch with a stub set function. Subsequent patches will implement the host command set functionality, and introduce mode switches. Signed-off-by: Prashant Malani Reviewed-by: Tzung-Bi Shih Link: https://lore.kernel.org/r/20220816214857.2088914-3-pmalani@chromium.org --- diff --git a/MAINTAINERS b/MAINTAINERS index 8a5012b..c1e4977 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4894,6 +4894,7 @@ M: Prashant Malani L: chrome-platform@lists.linux.dev S: Maintained F: drivers/platform/chrome/cros_ec_typec.c +F: drivers/platform/chrome/cros_typec_switch.c CHROMEOS EC USB PD NOTIFY DRIVER M: Prashant Malani diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig index c45fb37..6b954c5 100644 --- a/drivers/platform/chrome/Kconfig +++ b/drivers/platform/chrome/Kconfig @@ -265,6 +265,17 @@ config CHROMEOS_PRIVACY_SCREEN this should probably always be built into the kernel to avoid or minimize drm probe deferral. +config CROS_TYPEC_SWITCH + tristate "ChromeOS EC Type-C Switch Control" + depends on MFD_CROS_EC_DEV && TYPEC && ACPI + default MFD_CROS_EC_DEV + help + If you say Y here, you get support for configuring the ChromeOS EC Type-C + muxes and retimers. + + To compile this driver as a module, choose M here: the module will be + called cros_typec_switch. + source "drivers/platform/chrome/wilco_ec/Kconfig" # Kunit test cases diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile index f7e74a8..2950610 100644 --- a/drivers/platform/chrome/Makefile +++ b/drivers/platform/chrome/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o obj-$(CONFIG_CROS_EC) += cros_ec.o obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o obj-$(CONFIG_CROS_EC_ISHTP) += cros_ec_ishtp.o +obj-$(CONFIG_CROS_TYPEC_SWITCH) += cros_typec_switch.o obj-$(CONFIG_CROS_EC_RPMSG) += cros_ec_rpmsg.o obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_mec.o diff --git a/drivers/platform/chrome/cros_typec_switch.c b/drivers/platform/chrome/cros_typec_switch.c new file mode 100644 index 0000000..db773bf --- /dev/null +++ b/drivers/platform/chrome/cros_typec_switch.c @@ -0,0 +1,169 @@ +// 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 +#include +#include +#include +#include + +#define DRV_NAME "cros-typec-switch" + +/* Handles and other relevant data required for each port's switches. */ +struct cros_typec_port { + int port_num; + 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_retimer_set(struct typec_retimer *retimer, struct typec_retimer_state *state) +{ + return 0; +} + +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); + } +} + +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); + if (IS_ERR(port->retimer)) + return PTR_ERR(port->retimer); + + return 0; +} + +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 < 0 || index >= EC_USB_PD_MAX_PORTS) { + dev_err(fwnode->dev, "Invalid port index number: %llu", index); + ret = -EINVAL; + goto err_switch; + } + port->sdata = sdata; + port->port_num = index; + sdata->ports[index] = port; + + 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); + } + + return 0; +err_switch: + 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 = DRV_NAME, + .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 "); +MODULE_DESCRIPTION("ChromeOS EC Type-C Switch control"); +MODULE_LICENSE("GPL");