All of lore.kernel.org
 help / color / mirror / Atom feed
From: Igor Opaniuk <igor.opaniuk@gmail.com>
To: u-boot@lists.denx.de
Subject: [PATCH v5 1/4] drivers: tee: i2c trampoline driver
Date: Wed, 20 Jan 2021 19:55:27 +0200	[thread overview]
Message-ID: <20210120175530.92057-2-igor.opaniuk@gmail.com> (raw)
In-Reply-To: <20210120175530.92057-1-igor.opaniuk@gmail.com>

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>
---

(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;
+	}
+
+	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

  reply	other threads:[~2021-01-20 17:55 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-20 17:55 [PATCH v5 0/4] OP-TEE I2C trampoline and associated tests Igor Opaniuk
2021-01-20 17:55 ` Igor Opaniuk [this message]
2021-01-20 17:55 ` [PATCH v5 2/4] test: py: add pygit2 and pyelftools to requirements.txt Igor Opaniuk
2021-01-20 17:55 ` [PATCH v5 3/4] drivers: tee: sandbox: add rpc test ta emulation Igor Opaniuk
2021-01-21  7:39   ` Etienne Carriere
2021-01-21 10:41     ` Igor Opaniuk
2021-01-22 11:54       ` Etienne Carriere
2021-01-20 17:55 ` [PATCH v5 4/4] test: dm: tee: extend with RPC test Igor Opaniuk
2021-01-21  8:00   ` Etienne Carriere
2021-01-21 10:44     ` Igor Opaniuk

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210120175530.92057-2-igor.opaniuk@gmail.com \
    --to=igor.opaniuk@gmail.com \
    --cc=u-boot@lists.denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.