[PATCH v6 1/4] drivers: tee: i2c trampoline driver
Etienne Carriere
etienne.carriere at linaro.org
Fri Jan 22 14:59:34 CET 2021
Hi Igor,
With comment addressed or not:
Reviewed-by: Etienne Carriere <etienne.carriere at linaro.org>
On Fri, 22 Jan 2021 at 12:51, Igor Opaniuk <igor.opaniuk at foundries.io> wrote:
>
> From: Jorge Ramirez-Ortiz <jorge at 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 at foundries.io>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
>
> (no changes since v1)
>
> 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;
> + }
nitpicking:
if ((bool)(tee_flags & OPTEE_MSG_RPC_CMD_I2C_FLAGS_TEN_BIT) !=
(bool)(dev_flags & DM_I2C_CHIP_10BIT))
return -EINVAL;
br,
etienne
> +
> + 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;
> }
> --
> 2.25.1
>
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