On 01/06/20, 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.
any comments please? > > Signed-off-by: Jorge Ramirez-Ortiz <jo...@foundries.io> > --- > drivers/tee/optee/optee_msg.h | 18 +++++++++++ > drivers/tee/optee/rpc.c | 57 +++++++++++++++++++++++++++++++++++ > 2 files changed, 75 insertions(+) > > diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h > index 795bc19ae17a..b6cc964fdeea 100644 > --- a/drivers/tee/optee/optee_msg.h > +++ b/drivers/tee/optee/optee_msg.h > @@ -419,4 +419,22 @@ 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 > + * > + * [io] param[1].u.tmem.buf_ptr physical address > + * [io] param[1].u.tmem.size transfer size in bytes > + * [io] param[1].u.tmem.shm_ref shared memory reference > + * > + * [out] param[0].u.value.a bytes transferred > + * > + */ > +#define OPTEE_MSG_RPC_CMD_I2C_TRANSFER 8 > +#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..21d452805c6f 100644 > --- a/drivers/tee/optee/rpc.c > +++ b/drivers/tee/optee/rpc.c > @@ -9,6 +9,7 @@ > #include <linux/device.h> > #include <linux/slab.h> > #include <linux/tee_drv.h> > +#include <linux/i2c.h> > #include "optee_private.h" > #include "optee_smc.h" > > @@ -48,6 +49,59 @@ static void handle_rpc_func_cmd_get_time(struct > optee_msg_arg *arg) > bad: > arg->ret = TEEC_ERROR_BAD_PARAMETERS; > } > +static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx, > + struct optee_msg_arg *arg) > +{ > + struct i2c_client client; > + struct tee_shm *shm; > + int i, ret; > + char *buf; > + uint32_t attr[] = { > + OPTEE_MSG_ATTR_TYPE_VALUE_INPUT, > + OPTEE_MSG_ATTR_TYPE_TMEM_INOUT, > + OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT, > + }; > + > + if (arg->num_params != ARRAY_SIZE(attr)) > + goto bad; > + > + for (i = 0; i < ARRAY_SIZE(attr); i++) > + if ((arg->params[i].attr & OPTEE_MSG_ATTR_TYPE_MASK) != attr[i]) > + goto bad; > + > + shm = (struct tee_shm *)(unsigned long)arg->params[1].u.tmem.shm_ref; > + buf = (char *)shm->kaddr; > + > + client.addr = arg->params[0].u.value.c; > + client.adapter = i2c_get_adapter(arg->params[0].u.value.b); > + if (!client.adapter) > + goto bad; > + > + snprintf(client.name, I2C_NAME_SIZE, "i2c%d", client.adapter->nr); > + > + switch (arg->params[0].u.value.a) { > + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD: > + ret = i2c_master_recv(&client, buf, arg->params[1].u.tmem.size); > + break; > + case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR: > + ret = i2c_master_send(&client, buf, arg->params[1].u.tmem.size); > + break; > + default: > + i2c_put_adapter(client.adapter); > + goto bad; > + } > + > + if (ret >= 0) { > + arg->params[2].u.value.a = ret; > + arg->ret = TEEC_SUCCESS; > + } else > + arg->ret = TEEC_ERROR_COMMUNICATION; > + > + i2c_put_adapter(client.adapter); > + return; > +bad: > + arg->ret = TEEC_ERROR_BAD_PARAMETERS; > +} > > static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key) > { > @@ -382,6 +436,9 @@ 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); > } > -- > 2.17.1 >