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authorJorge Ramirez-Ortiz <jorge@foundries.io>2020-08-14 13:12:21 +0200
committerJens Wiklander <jens.wiklander@linaro.org>2020-08-21 11:41:45 +0200
commitc05210ab975771e161427eb47696b869d820bdaf (patch)
treea2c858ff2aa873c31a4c7882702c992cdce9d0b5 /drivers/tee
parentLinux 5.9-rc1 (diff)
downloadlinux-c05210ab975771e161427eb47696b869d820bdaf.tar.xz
linux-c05210ab975771e161427eb47696b869d820bdaf.zip
drivers: optee: allow op-tee to access devices on the i2c bus
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. Signed-off-by: Jorge Ramirez-Ortiz <jorge@foundries.io> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Diffstat (limited to 'drivers/tee')
-rw-r--r--drivers/tee/optee/optee_msg.h21
-rw-r--r--drivers/tee/optee/optee_private.h1
-rw-r--r--drivers/tee/optee/rpc.c95
3 files changed, 117 insertions, 0 deletions
diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h
index 795bc19ae17a..7b2d919da2ac 100644
--- a/drivers/tee/optee/optee_msg.h
+++ b/drivers/tee/optee/optee_msg.h
@@ -419,4 +419,25 @@ 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_private.h b/drivers/tee/optee/optee_private.h
index 8b71839a357e..e25b216a14ef 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -17,6 +17,7 @@
/* Some Global Platform error codes used in this driver */
#define TEEC_SUCCESS 0x00000000
#define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006
+#define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A
#define TEEC_ERROR_COMMUNICATION 0xFFFF000E
#define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C
#define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010
diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
index b4ade54d1f28..64a206c56264 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 +50,97 @@ bad:
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 = { 0 };
+ struct tee_param *params;
+ size_t i;
+ int ret = -EOPNOTSUPP;
+ u8 attr[] = {
+ TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
+ 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++) {
+ if (params[i].attr != attr[i])
+ goto bad;
+ }
+
+ client.adapter = i2c_get_adapter(params[0].u.value.b);
+ if (!client.adapter)
+ goto bad;
+
+ if (params[1].u.value.a & OPTEE_MSG_RPC_CMD_I2C_FLAGS_TEN_BIT) {
+ if (!i2c_check_functionality(client.adapter,
+ I2C_FUNC_10BIT_ADDR)) {
+ i2c_put_adapter(client.adapter);
+ goto bad;
+ }
+
+ client.flags = I2C_CLIENT_TEN;
+ }
+
+ client.addr = params[0].u.value.c;
+ snprintf(client.name, I2C_NAME_SIZE, "i2c%d", client.adapter->nr);
+
+ switch (params[0].u.value.a) {
+ case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_RD:
+ ret = i2c_master_recv(&client, params[2].u.memref.shm->kaddr,
+ params[2].u.memref.size);
+ break;
+ case OPTEE_MSG_RPC_CMD_I2C_TRANSFER_WR:
+ ret = i2c_master_send(&client, params[2].u.memref.shm->kaddr,
+ params[2].u.memref.size);
+ break;
+ default:
+ i2c_put_adapter(client.adapter);
+ goto bad;
+ }
+
+ if (ret < 0) {
+ arg->ret = TEEC_ERROR_COMMUNICATION;
+ } else {
+ params[3].u.value.a = ret;
+ if (optee_to_msg_param(arg->params, arg->num_params, params))
+ arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+ else
+ arg->ret = TEEC_SUCCESS;
+ }
+
+ 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_NOT_SUPPORTED;
+}
+#endif
+
static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key)
{
struct wq_entry *w;
@@ -382,6 +474,9 @@ 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);
}