dm: tpm: Add a uclass for Trusted Platform Modules

[karo-tx-uboot.git] / drivers / tpm / tpm-uclass.c

diff --git a/drivers/tpm/tpm-uclass.c b/drivers/tpm/tpm-uclass.c
new file mode 100644 (file)
index 0000000..b6e1fc5
--- /dev/null
+++ b/drivers/tpm/tpm-uclass.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <tpm.h>
+#include <linux/unaligned/be_byteshift.h>
+#include "tpm_internal.h"
+
+int tpm_open(struct udevice *dev)
+{
+       struct tpm_ops *ops = tpm_get_ops(dev);
+
+       if (!ops->open)
+               return -ENOSYS;
+
+       return ops->open(dev);
+}
+
+int tpm_close(struct udevice *dev)
+{
+       struct tpm_ops *ops = tpm_get_ops(dev);
+
+       if (!ops->close)
+               return -ENOSYS;
+
+       return ops->close(dev);
+}
+
+int tpm_get_desc(struct udevice *dev, char *buf, int size)
+{
+       struct tpm_ops *ops = tpm_get_ops(dev);
+
+       if (!ops->get_desc)
+               return -ENOSYS;
+
+       return ops->get_desc(dev, buf, size);
+}
+
+/* Returns max number of milliseconds to wait */
+static ulong tpm_tis_i2c_calc_ordinal_duration(struct tpm_chip_priv *priv,
+                                              u32 ordinal)
+{
+       int duration_idx = TPM_UNDEFINED;
+       int duration = 0;
+
+       if (ordinal < TPM_MAX_ORDINAL) {
+               duration_idx = tpm_ordinal_duration[ordinal];
+       } else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
+                       TPM_MAX_PROTECTED_ORDINAL) {
+               duration_idx = tpm_protected_ordinal_duration[
+                               ordinal & TPM_PROTECTED_ORDINAL_MASK];
+       }
+
+       if (duration_idx != TPM_UNDEFINED)
+               duration = priv->duration_ms[duration_idx];
+
+       if (duration <= 0)
+               return 2 * 60 * 1000; /* Two minutes timeout */
+       else
+               return duration;
+}
+
+int tpm_xfer(struct udevice *dev, const uint8_t *sendbuf, size_t send_size,
+       uint8_t *recvbuf, size_t *recv_size)
+{
+       struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
+       struct tpm_ops *ops = tpm_get_ops(dev);
+       ulong start, stop;
+       uint count, ordinal;
+       int ret, ret2;
+
+       if (ops->xfer)
+               return ops->xfer(dev, sendbuf, send_size, recvbuf, recv_size);
+
+       if (!ops->send || !ops->recv)
+               return -ENOSYS;
+
+       /* switch endianess: big->little */
+       count = get_unaligned_be32(sendbuf + TPM_CMD_COUNT_BYTE);
+       ordinal = get_unaligned_be32(sendbuf + TPM_CMD_ORDINAL_BYTE);
+
+       if (count == 0) {
+               debug("no data\n");
+               return -ENODATA;
+       }
+       if (count > send_size) {
+               debug("invalid count value %x %zx\n", count, send_size);
+               return -E2BIG;
+       }
+
+       debug("%s: Calling send\n", __func__);
+       ret = ops->send(dev, sendbuf, send_size);
+       if (ret < 0)
+               return ret;
+
+       start = get_timer(0);
+       stop = tpm_tis_i2c_calc_ordinal_duration(priv, ordinal);
+       do {
+               ret = ops->recv(dev, priv->buf, sizeof(priv->buf));
+               if (ret >= 0) {
+                       if (ret > *recv_size)
+                               return -ENOSPC;
+                       memcpy(recvbuf, priv->buf, ret);
+                       *recv_size = ret;
+                       ret = 0;
+                       break;
+               } else if (ret != -EAGAIN) {
+                       return ret;
+               }
+
+               mdelay(priv->retry_time_ms);
+               if (get_timer(start) > stop) {
+                       ret = -ETIMEDOUT;
+                       break;
+               }
+       } while (ret);
+
+       ret2 = ops->cleanup ? ops->cleanup(dev) : 0;
+
+       return ret2 ? ret2 : ret;
+}
+
+UCLASS_DRIVER(tpm) = {
+       .id             = UCLASS_TPM,
+       .name           = "tpm",
+       .flags          = DM_UC_FLAG_SEQ_ALIAS,
+       .per_device_auto_alloc_size     = sizeof(struct tpm_chip_priv),
+};