diff --git a/MAINTAINERS b/MAINTAINERS index 55af015174a5..63f59748d661 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -25009,6 +25009,7 @@ F: drivers/hwmon/pmbus/stef48h28.c ST STM32 FIREWALL M: Gatien Chevallier S: Maintained +F: drivers/bus/stm32_dbg_bus.c F: drivers/bus/stm32_etzpc.c F: drivers/bus/stm32_firewall.c F: drivers/bus/stm32_rifsc.c diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig index 2a1b46f07080..7a1b04007efb 100644 --- a/drivers/bus/Kconfig +++ b/drivers/bus/Kconfig @@ -169,6 +169,16 @@ config QCOM_SSC_BLOCK_BUS i2c/spi/uart controllers, a hexagon core, and a clock controller which provides clocks for the above. +config STM32_DBG_BUS + tristate "OP-TEE based debug access bus" + depends on OPTEE && STM32_FIREWALL + depends on ARCH_STM32 || COMPILE_TEST + help + Select this to get the support for the OP-TEE based STM32 debug bus + driver that is used to handle debug-related peripherals on STM32 + platforms when the debug configuration is not accessible by the + normal world. + config STM32_FIREWALL bool "STM32 Firewall framework" depends on (ARCH_STM32 || COMPILE_TEST) && OF diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile index 8e693fe8a03a..799724cfc2df 100644 --- a/drivers/bus/Makefile +++ b/drivers/bus/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_OMAP_INTERCONNECT) += omap_l3_smx.o omap_l3_noc.o obj-$(CONFIG_OMAP_OCP2SCP) += omap-ocp2scp.o obj-$(CONFIG_QCOM_EBI2) += qcom-ebi2.o obj-$(CONFIG_QCOM_SSC_BLOCK_BUS) += qcom-ssc-block-bus.o +obj-$(CONFIG_STM32_DBG_BUS) += stm32_dbg_bus.o obj-$(CONFIG_STM32_FIREWALL) += stm32_firewall.o stm32_rifsc.o stm32_etzpc.o obj-$(CONFIG_SUN50I_DE2_BUS) += sun50i-de2.o obj-$(CONFIG_SUNXI_RSB) += sunxi-rsb.o diff --git a/drivers/bus/stm32_dbg_bus.c b/drivers/bus/stm32_dbg_bus.c new file mode 100644 index 000000000000..e30ef3465609 --- /dev/null +++ b/drivers/bus/stm32_dbg_bus.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2026, STMicroelectronics - All Rights Reserved + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +enum stm32_dbg_profile { + PERIPHERAL_DBG_PROFILE = 0, + HDP_DBG_PROFILE = 1, +}; + +enum stm32_dbg_pta_command { + /* + * PTA_CMD_GRANT_DBG_ACCESS - Verify the debug configuration against the given debug profile + * and grant access or not + * + * [in] value[0].a Debug profile to grant access to. + */ + PTA_CMD_GRANT_DBG_ACCESS, +}; + +/** + * struct stm32_dbg_bus - OP-TEE based STM32 debug bus private data + * @dev: STM32 debug bus device. + * @ctx: OP-TEE context handler. + */ +struct stm32_dbg_bus { + struct device *dev; + struct tee_context *ctx; +}; + +/* Expect at most 1 instance of this driver */ +static struct stm32_dbg_bus *stm32_dbg_bus_priv; + +static int stm32_dbg_pta_open_session(u32 *id) +{ + struct tee_client_device *dbg_bus_dev = to_tee_client_device(stm32_dbg_bus_priv->dev); + struct tee_ioctl_open_session_arg sess_arg; + int ret; + + memset(&sess_arg, 0, sizeof(sess_arg)); + export_uuid(sess_arg.uuid, &dbg_bus_dev->id.uuid); + sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; + + ret = tee_client_open_session(stm32_dbg_bus_priv->ctx, &sess_arg, NULL); + if (ret < 0 || sess_arg.ret) { + dev_err(stm32_dbg_bus_priv->dev, "Failed opening tee session, err: %#x\n", + sess_arg.ret); + return -EOPNOTSUPP; + } + + *id = sess_arg.session; + + return 0; +} + +static void stm32_dbg_pta_close_session(u32 id) +{ + tee_client_close_session(stm32_dbg_bus_priv->ctx, id); +} + +static int stm32_dbg_bus_grant_access(struct stm32_firewall_controller *ctrl, u32 dbg_profile) +{ + struct tee_ioctl_invoke_arg inv_arg = {0}; + struct tee_param param[1] = {0}; + u32 session_id; + int ret; + + if (dbg_profile != PERIPHERAL_DBG_PROFILE && dbg_profile != HDP_DBG_PROFILE) + return -EOPNOTSUPP; + + ret = stm32_dbg_pta_open_session(&session_id); + if (ret) + return ret; + + inv_arg.func = PTA_CMD_GRANT_DBG_ACCESS; + inv_arg.session = session_id; + inv_arg.num_params = 1; + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT; + param[0].u.value.a = dbg_profile; + + ret = tee_client_invoke_func(stm32_dbg_bus_priv->ctx, &inv_arg, param); + if (ret < 0 || inv_arg.ret != 0) { + dev_dbg(stm32_dbg_bus_priv->dev, + "When invoking function, err %x, TEE returns: %x\n", ret, inv_arg.ret); + if (!ret) + ret = -EACCES; + } + + stm32_dbg_pta_close_session(session_id); + + return ret; +} + +/* Implement mandatory release_access ops even if it does nothing*/ +static void stm32_dbg_bus_release_access(struct stm32_firewall_controller *ctrl, u32 dbg_profile) +{ +} + +static int stm32_dbg_bus_plat_probe(struct platform_device *pdev) +{ + struct stm32_firewall_controller *dbg_controller; + int ret; + + /* Defer if OP-TEE service is not yet available */ + if (!stm32_dbg_bus_priv) + return -EPROBE_DEFER; + + dbg_controller = devm_kzalloc(&pdev->dev, sizeof(*dbg_controller), GFP_KERNEL); + if (!dbg_controller) + return dev_err_probe(&pdev->dev, -ENOMEM, "Couldn't allocate debug controller\n"); + + dbg_controller->dev = &pdev->dev; + dbg_controller->mmio = NULL; + dbg_controller->name = dev_driver_string(dbg_controller->dev); + dbg_controller->type = STM32_PERIPHERAL_FIREWALL; + dbg_controller->grant_access = stm32_dbg_bus_grant_access; + dbg_controller->release_access = stm32_dbg_bus_release_access; + + ret = stm32_firewall_controller_register(dbg_controller); + if (ret) { + dev_err(dbg_controller->dev, "Couldn't register as a firewall controller: %d", ret); + return ret; + } + + ret = stm32_firewall_populate_bus(dbg_controller); + if (ret) { + dev_err(dbg_controller->dev, "Couldn't populate debug bus: %d", ret); + stm32_firewall_controller_unregister(dbg_controller); + return ret; + } + + pm_runtime_enable(&pdev->dev); + + ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); + if (ret) { + dev_err(dbg_controller->dev, "Couldn't populate the node: %d", ret); + stm32_firewall_controller_unregister(dbg_controller); + return ret; + } + + return 0; +} + +static const struct of_device_id stm32_dbg_bus_of_match[] = { + { .compatible = "st,stm32mp131-dbg-bus", }, + { .compatible = "st,stm32mp151-dbg-bus", }, + { }, +}; +MODULE_DEVICE_TABLE(of, stm32_dbg_bus_of_match); + +static struct platform_driver stm32_dbg_bus_driver = { + .probe = stm32_dbg_bus_plat_probe, + .driver = { + .name = "stm32-dbg-bus", + .of_match_table = stm32_dbg_bus_of_match, + }, +}; + +static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + return (ver->impl_id == TEE_IMPL_ID_OPTEE); +} + +static void stm32_dbg_bus_remove(struct tee_client_device *tee_dev) +{ + tee_client_close_context(stm32_dbg_bus_priv->ctx); + stm32_dbg_bus_priv = NULL; + + of_platform_depopulate(&tee_dev->dev); +} + +static int stm32_dbg_bus_probe(struct tee_client_device *tee_dev) +{ + struct device *dev = &tee_dev->dev; + struct stm32_dbg_bus *priv; + int ret = 0; + + if (stm32_dbg_bus_priv) + return dev_err_probe(dev, -EBUSY, + "A STM32 debug bus device is already initialized\n"); + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + /* Open context with TEE driver */ + priv->ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL); + if (IS_ERR_OR_NULL(priv->ctx)) + return dev_err_probe(dev, PTR_ERR_OR_ZERO(priv->ctx), "Cannot open TEE context\n"); + + stm32_dbg_bus_priv = priv; + stm32_dbg_bus_priv->dev = dev; + + return ret; +} + +static const struct tee_client_device_id optee_dbg_bus_id_table[] = { + {UUID_INIT(0xdd05bc8b, 0x9f3b, 0x49f0, + 0xb6, 0x49, 0x01, 0xaa, 0x10, 0xc1, 0xc2, 0x10)}, + {} +}; + +static struct tee_client_driver stm32_optee_dbg_bus_driver = { + .id_table = optee_dbg_bus_id_table, + .probe = stm32_dbg_bus_probe, + .remove = stm32_dbg_bus_remove, + .driver = { + .name = "optee_dbg_bus", + }, +}; + +static void __exit stm32_optee_dbg_bus_driver_exit(void) +{ + platform_driver_unregister(&stm32_dbg_bus_driver); + tee_client_driver_unregister(&stm32_optee_dbg_bus_driver); +} +module_exit(stm32_optee_dbg_bus_driver_exit); + +static int __init stm32_optee_dbg_bus_driver_init(void) +{ + int err; + + err = tee_client_driver_register(&stm32_optee_dbg_bus_driver); + if (err) + return err; + + err = platform_driver_register(&stm32_dbg_bus_driver); + if (err) + tee_client_driver_unregister(&stm32_optee_dbg_bus_driver); + + return err; +} +module_init(stm32_optee_dbg_bus_driver_init); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Gatien Chevallier "); +MODULE_DESCRIPTION("OP-TEE based STM32 debug access bus driver");