From: Jorge Ramirez-Ortiz jorge@foundries.io
This commit gives the secure world access to the I2C bus so it can communicate with I2C slaves (typically those would be secure elements like the NXP SE050).
A similar service implementation has been merged in linux: c05210ab ("drivers: optee: allow op-tee to access devices on the i2c bus")
Signed-off-by: Jorge Ramirez-Ortiz jorge@foundries.io Reviewed-by: Simon Glass sjg@chromium.org Reviewed-by: Etienne Carriere etienne.carriere@linaro.org ---
drivers/tee/optee/Makefile | 1 + drivers/tee/optee/i2c.c | 90 ++++++++++++++++++++++++ drivers/tee/optee/optee_msg.h | 21 ++++++ drivers/tee/optee/optee_msg_supplicant.h | 5 ++ drivers/tee/optee/optee_private.h | 17 +++++ drivers/tee/optee/supplicant.c | 3 + 6 files changed, 137 insertions(+) create mode 100644 drivers/tee/optee/i2c.c
diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile index 928d3f8002..068c6e7aa1 100644 --- a/drivers/tee/optee/Makefile +++ b/drivers/tee/optee/Makefile @@ -2,4 +2,5 @@
obj-y += core.o obj-y += supplicant.o +obj-$(CONFIG_DM_I2C) += i2c.o obj-$(CONFIG_SUPPORT_EMMC_RPMB) += rpmb.o diff --git a/drivers/tee/optee/i2c.c b/drivers/tee/optee/i2c.c new file mode 100644 index 0000000000..ef4e10f991 --- /dev/null +++ b/drivers/tee/optee/i2c.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: BSD-2-Clause +/* + * Copyright (c) 2020 Foundries.io Ltd + */ + +#include <common.h> +#include <dm.h> +#include <i2c.h> +#include <tee.h> +#include "optee_msg.h" +#include "optee_private.h" + +static int check_xfer_flags(struct udevice *chip, uint tee_flags) +{ + uint flags; + int ret; + + ret = i2c_get_chip_flags(chip, &flags); + if (ret) + return ret; + + if (tee_flags & OPTEE_MSG_RPC_CMD_I2C_FLAGS_TEN_BIT) { + if (!(flags & DM_I2C_CHIP_10BIT)) + return -EINVAL; + } else { + if (flags & DM_I2C_CHIP_10BIT) + return -EINVAL; + } + + return 0; +} + +void optee_suppl_cmd_i2c_transfer(struct optee_msg_arg *arg) +{ + const u8 attr[] = { + OPTEE_MSG_ATTR_TYPE_VALUE_INPUT, + OPTEE_MSG_ATTR_TYPE_VALUE_INPUT, + OPTEE_MSG_ATTR_TYPE_RMEM_INOUT, + OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT, + }; + struct udevice *chip_dev; + struct tee_shm *shm; + u8 *buf; + int ret; + + if (arg->num_params != ARRAY_SIZE(attr) || + arg->params[0].attr != attr[0] || + arg->params[1].attr != attr[1] || + arg->params[2].attr != attr[2] || + arg->params[3].attr != attr[3]) { + goto bad; + } + + shm = (struct tee_shm *)(unsigned long)arg->params[2].u.rmem.shm_ref; + buf = shm->addr; + if (!buf) + goto bad; + + if (i2c_get_chip_for_busnum((int)arg->params[0].u.value.b, + (int)arg->params[0].u.value.c, + 0, &chip_dev)) + goto bad; + + if (check_xfer_flags(chip_dev, arg->params[1].u.value.a)) + goto bad; + + switch (arg->params[0].u.value.a) { + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD: + ret = dm_i2c_read(chip_dev, 0, buf, + (size_t)arg->params[2].u.rmem.size); + break; + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR: + ret = dm_i2c_write(chip_dev, 0, buf, + (size_t)arg->params[2].u.rmem.size); + break; + default: + goto bad; + } + + if (ret) { + arg->ret = TEE_ERROR_COMMUNICATION; + } else { + arg->params[3].u.value.a = arg->params[2].u.rmem.size; + arg->ret = TEE_SUCCESS; + } + + return; +bad: + arg->ret = TEE_ERROR_BAD_PARAMETERS; +} diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h index 24c60960fc..8d40ce60c2 100644 --- a/drivers/tee/optee/optee_msg.h +++ b/drivers/tee/optee/optee_msg.h @@ -422,4 +422,25 @@ struct optee_msg_arg { */ #define OPTEE_MSG_RPC_CMD_SHM_FREE 7
+/* + * Access a device on an i2c bus + * + * [in] param[0].u.value.a mode: RD(0), WR(1) + * [in] param[0].u.value.b i2c adapter + * [in] param[0].u.value.c i2c chip + * + * [in] param[1].u.value.a i2c control flags + * + * [in/out] memref[2] buffer to exchange the transfer data + * with the secure world + * + * [out] param[3].u.value.a bytes transferred by the driver + */ +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER 21 +/* I2C master transfer modes */ +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD 0 +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR 1 +/* I2C master control flags */ +#define OPTEE_MSG_RPC_CMD_I2C_FLAGS_TEN_BIT BIT(0) + #endif /* _OPTEE_MSG_H */ diff --git a/drivers/tee/optee/optee_msg_supplicant.h b/drivers/tee/optee/optee_msg_supplicant.h index a0fb8063c8..963cfd4782 100644 --- a/drivers/tee/optee/optee_msg_supplicant.h +++ b/drivers/tee/optee/optee_msg_supplicant.h @@ -147,6 +147,11 @@ #define OPTEE_MSG_RPC_CMD_SHM_ALLOC 6 #define OPTEE_MSG_RPC_CMD_SHM_FREE 7
+/* + * I2C bus access + */ +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER 21 + /* * Was OPTEE_MSG_RPC_CMD_SQL_FS, which isn't supported any longer */ diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 9442d1c176..1f07a27ee4 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -60,6 +60,23 @@ static inline void optee_suppl_rpmb_release(struct udevice *dev) } #endif
+#ifdef CONFIG_DM_I2C +/** + * optee_suppl_cmd_i2c_transfer() - route I2C requests to an I2C chip + * @arg: OP-TEE message (layout specified in optee_msg.h) defining the + * transfer mode (read/write), adapter, chip and control flags. + * + * Handles OP-TEE requests to transfer data to the I2C chip on the I2C adapter. + */ +void optee_suppl_cmd_i2c_transfer(struct optee_msg_arg *arg); +#else +static inline void optee_suppl_cmd_i2c_transfer(struct optee_msg_arg *arg) +{ + debug("OPTEE_MSG_RPC_CMD_I2C_TRANSFER not implemented\n"); + arg->ret = TEE_ERROR_NOT_IMPLEMENTED; +} +#endif + void *optee_alloc_and_init_page_list(void *buf, ulong len, u64 *phys_buf_ptr);
#endif /* __OPTEE_PRIVATE_H */ diff --git a/drivers/tee/optee/supplicant.c b/drivers/tee/optee/supplicant.c index ae042b9a20..f9dd874b59 100644 --- a/drivers/tee/optee/supplicant.c +++ b/drivers/tee/optee/supplicant.c @@ -89,6 +89,9 @@ void optee_suppl_cmd(struct udevice *dev, struct tee_shm *shm_arg, case OPTEE_MSG_RPC_CMD_RPMB: optee_suppl_cmd_rpmb(dev, arg); break; + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER: + optee_suppl_cmd_i2c_transfer(arg); + break; default: arg->ret = TEE_ERROR_NOT_IMPLEMENTED; }