On 22/07/20, Jorge Ramirez-Ortiz wrote: > Some secure elements like NXP's SE050 sit on I2C buses. For OP-TEE to > control this type of cryptographic devices it needs coordinated access > to the bus, so collisions and RUNTIME_PM dont get in the way. > > This trampoline driver allow OP-TEE to access them. > Tested on imx8mm LPDDR4 > > Signed-off-by: Jorge Ramirez-Ortiz <jo...@foundries.io> > --- > v6: compile out if CONFIG_I2C not enabled > v5: alphabetic order of includes > v4: remove unnecessary extra line in optee_msg.h > v3: use from/to msg param to support all types of memory > modify OPTEE_MSG_RPC_CMD_I2C_TRANSFER message id > > drivers/tee/optee/optee_msg.h | 16 +++++++ > drivers/tee/optee/rpc.c | 88 +++++++++++++++++++++++++++++++++++ > 2 files changed, 104 insertions(+) > > diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h > index 795bc19ae17a..14b580f55356 100644 > --- a/drivers/tee/optee/optee_msg.h > +++ b/drivers/tee/optee/optee_msg.h > @@ -419,4 +419,20 @@ 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/out] memref[1] buffer to exchange the transfer > data > + * with the secure world > + * > + * [out] param[0].u.value.a bytes transferred by the driver > + */ > +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER 21 > +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD 0 > +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR 1 > + > #endif /* _OPTEE_MSG_H */ > diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c > index b4ade54d1f28..5fd5c6c93896 100644 > --- a/drivers/tee/optee/rpc.c > +++ b/drivers/tee/optee/rpc.c > @@ -7,6 +7,7 @@ > > #include <linux/delay.h> > #include <linux/device.h> > +#include <linux/i2c.h> > #include <linux/slab.h> > #include <linux/tee_drv.h> > #include "optee_private.h" > @@ -49,6 +50,90 @@ static void handle_rpc_func_cmd_get_time(struct > optee_msg_arg *arg) > arg->ret = TEEC_ERROR_BAD_PARAMETERS; > } > > +#if IS_ENABLED(CONFIG_I2C) > +static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx, > + struct optee_msg_arg *arg) > +{ > + struct i2c_client client; > + struct tee_param *params; > + uint32_t type; > + int i, ret; > + size_t len; > + char *buf; > + uint32_t attr[] = { > + TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT, > + TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT, > + TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT, > + }; > + > + if (arg->num_params != ARRAY_SIZE(attr)) { > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + return; > + } > + > + params = kmalloc_array(arg->num_params, sizeof(struct tee_param), > + GFP_KERNEL); > + if (!params) { > + arg->ret = TEEC_ERROR_OUT_OF_MEMORY; > + return; > + } > + > + if (optee_from_msg_param(params, arg->num_params, arg->params)) > + goto bad; > + > + for (i = 0; i < arg->num_params; i++) { > + type = params[i].attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK; > + if (type != attr[i]) > + goto bad; > + } > + > + client.addr = params[0].u.value.c; > + client.adapter = i2c_get_adapter(params[0].u.value.b); > + if (!client.adapter) > + goto bad; > + > + snprintf(client.name, I2C_NAME_SIZE, "i2c%d", client.adapter->nr); > + > + buf = params[1].u.memref.shm->kaddr; > + len = params[1].u.memref.size; > + > + switch (params[0].u.value.a) { > + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD: > + ret = i2c_master_recv(&client, buf, len); > + break; > + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR: > + ret = i2c_master_send(&client, buf, len); > + break; > + default: > + i2c_put_adapter(client.adapter); > + goto bad; > + } > + > + if (ret >= 0) { > + params[2].u.value.a = ret; > + arg->ret = TEEC_SUCCESS; > + } else { > + arg->ret = TEEC_ERROR_COMMUNICATION; > + } > + > + if (optee_to_msg_param(arg->params, arg->num_params, params)) > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > + > + i2c_put_adapter(client.adapter); > + kfree(params); > + return; > +bad: > + kfree(params); > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > +} > +#else > +static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx, > + struct optee_msg_arg *arg) > +{ > + arg->ret = TEEC_ERROR_COMMUNICATION; > +} > +#endif > + > static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key) > { > struct wq_entry *w; > @@ -382,6 +467,9 @@ static void handle_rpc_func_cmd(struct tee_context *ctx, > struct optee *optee, > case OPTEE_MSG_RPC_CMD_SHM_FREE: > handle_rpc_func_cmd_shm_free(ctx, arg); > break; > + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER: > + handle_rpc_func_cmd_i2c_transfer(ctx, arg); > + break; > default: > handle_rpc_supp_cmd(ctx, arg); > }
any comments to this feature? TIA