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authorJason Gunthorpe <jgunthorpe@obsidianresearch.com>2013-10-06 12:43:13 -0600
committerPeter Huewe <peterhuewe@gmx.de>2013-10-22 19:43:04 +0200
commit4c336e4b1556f4b722ba597bc6e3df786968a600 (patch)
tree06c87151784a45fa4ae7beb7c0121fd045b469a1 /drivers/char
parent187eea0c353abd4ffa3a9cc86a660af9605fcb10 (diff)
downloadlinux-linaro-stable-4c336e4b1556f4b722ba597bc6e3df786968a600.tar.gz
tpm: Add support for the Nuvoton NPCT501 I2C TPM
This chip is/was also branded as a Winbond WPCT301. Originally written by Dan Morav <dmorav@nuvoton.com> and posted to LKML: https://lkml.org/lkml/2011/9/7/206 The original posting was not merged, I have taken it as a starting point, forward ported, tested and revised the driver: - Rework interrupt handling to work properly with level triggered interrupts. The old version just locked up. - Synchronize various items with Peter Huewe's Infineon driver: * Add durations/timeouts sysfs calls * Remove I2C device auto-detection * Don't fiddle with chip->release * Call tpm_dev_vendor_release in the probe error path * Use MODULE_DEVICE_TABLE for the I2C ids * Provide OF compatible strings for DT support * Use SIMPLE_DEV_PM_OPS * Use module_i2c_driver - checkpatch cleanups - Testing on ARM Kirkwood with GPIO interrupts, with this device tree: tpm@57 { compatible = "nuvoton,npct501"; reg = <0x57>; interrupt-parent = <&gpio1>; interrupts = <6 IRQ_TYPE_LEVEL_LOW>; }; Signed-off-by: Dan Morav <dmorav@nuvoton.com> [jgg: revised and tested] Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> [phuewe: minor whitespace changes, fixed module name in kconfig] Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/Kconfig10
-rw-r--r--drivers/char/tpm/Makefile1
-rw-r--r--drivers/char/tpm/tpm_i2c_nuvoton.c710
3 files changed, 721 insertions, 0 deletions
diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index 94c0c74434ea..ade71c134a1a 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -44,6 +44,16 @@ config TCG_TIS_I2C_INFINEON
To compile this driver as a module, choose M here; the module
will be called tpm_tis_i2c_infineon.
+config TCG_TIS_I2C_NUVOTON
+ tristate "TPM Interface Specification 1.2 Interface (I2C - Nuvoton)"
+ depends on I2C
+ ---help---
+ If you have a TPM security chip with an I2C interface from
+ Nuvoton Technology Corp. say Yes and it will be accessible
+ from within Linux.
+ To compile this driver as a module, choose M here; the module
+ will be called tpm_i2c_nuvoton.
+
config TCG_NSC
tristate "National Semiconductor TPM Interface"
depends on X86
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 15df2f38ae42..07ee67cf3341 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -14,6 +14,7 @@ endif
endif
obj-$(CONFIG_TCG_TIS) += tpm_tis.o
obj-$(CONFIG_TCG_TIS_I2C_INFINEON) += tpm_i2c_infineon.o
+obj-$(CONFIG_TCG_TIS_I2C_NUVOTON) += tpm_i2c_nuvoton.o
obj-$(CONFIG_TCG_NSC) += tpm_nsc.o
obj-$(CONFIG_TCG_ATMEL) += tpm_atmel.o
obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o
diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
new file mode 100644
index 000000000000..6276fea01ff0
--- /dev/null
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -0,0 +1,710 @@
+/******************************************************************************
+ * Nuvoton TPM I2C Device Driver Interface for WPCT301/NPCT501,
+ * based on the TCG TPM Interface Spec version 1.2.
+ * Specifications at www.trustedcomputinggroup.org
+ *
+ * Copyright (C) 2011, Nuvoton Technology Corporation.
+ * Dan Morav <dan.morav@nuvoton.com>
+ * Copyright (C) 2013, Obsidian Research Corp.
+ * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/>.
+ *
+ * Nuvoton contact information: APC.Support@nuvoton.com
+ *****************************************************************************/
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/i2c.h>
+#include "tpm.h"
+
+/* I2C interface offsets */
+#define TPM_STS 0x00
+#define TPM_BURST_COUNT 0x01
+#define TPM_DATA_FIFO_W 0x20
+#define TPM_DATA_FIFO_R 0x40
+#define TPM_VID_DID_RID 0x60
+/* TPM command header size */
+#define TPM_HEADER_SIZE 10
+#define TPM_RETRY 5
+/*
+ * I2C bus device maximum buffer size w/o counting I2C address or command
+ * i.e. max size required for I2C write is 34 = addr, command, 32 bytes data
+ */
+#define TPM_I2C_MAX_BUF_SIZE 32
+#define TPM_I2C_RETRY_COUNT 32
+#define TPM_I2C_BUS_DELAY 1 /* msec */
+#define TPM_I2C_RETRY_DELAY_SHORT 2 /* msec */
+#define TPM_I2C_RETRY_DELAY_LONG 10 /* msec */
+
+#define I2C_DRIVER_NAME "tpm_i2c_nuvoton"
+
+struct priv_data {
+ unsigned int intrs;
+};
+
+static s32 i2c_nuvoton_read_buf(struct i2c_client *client, u8 offset, u8 size,
+ u8 *data)
+{
+ s32 status;
+
+ status = i2c_smbus_read_i2c_block_data(client, offset, size, data);
+ dev_dbg(&client->dev,
+ "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
+ offset, size, (int)size, data, status);
+ return status;
+}
+
+static s32 i2c_nuvoton_write_buf(struct i2c_client *client, u8 offset, u8 size,
+ u8 *data)
+{
+ s32 status;
+
+ status = i2c_smbus_write_i2c_block_data(client, offset, size, data);
+ dev_dbg(&client->dev,
+ "%s(offset=%u size=%u data=%*ph) -> sts=%d\n", __func__,
+ offset, size, (int)size, data, status);
+ return status;
+}
+
+#define TPM_STS_VALID 0x80
+#define TPM_STS_COMMAND_READY 0x40
+#define TPM_STS_GO 0x20
+#define TPM_STS_DATA_AVAIL 0x10
+#define TPM_STS_EXPECT 0x08
+#define TPM_STS_RESPONSE_RETRY 0x02
+#define TPM_STS_ERR_VAL 0x07 /* bit2...bit0 reads always 0 */
+
+#define TPM_I2C_SHORT_TIMEOUT 750 /* ms */
+#define TPM_I2C_LONG_TIMEOUT 2000 /* 2 sec */
+
+/* read TPM_STS register */
+static u8 i2c_nuvoton_read_status(struct tpm_chip *chip)
+{
+ struct i2c_client *client = to_i2c_client(chip->dev);
+ s32 status;
+ u8 data;
+
+ status = i2c_nuvoton_read_buf(client, TPM_STS, 1, &data);
+ if (status <= 0) {
+ dev_err(chip->dev, "%s() error return %d\n", __func__,
+ status);
+ data = TPM_STS_ERR_VAL;
+ }
+
+ return data;
+}
+
+/* write byte to TPM_STS register */
+static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
+{
+ s32 status;
+ int i;
+
+ /* this causes the current command to be aborted */
+ for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
+ status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
+ msleep(TPM_I2C_BUS_DELAY);
+ }
+ return status;
+}
+
+/* write commandReady to TPM_STS register */
+static void i2c_nuvoton_ready(struct tpm_chip *chip)
+{
+ struct i2c_client *client = to_i2c_client(chip->dev);
+ s32 status;
+
+ /* this causes the current command to be aborted */
+ status = i2c_nuvoton_write_status(client, TPM_STS_COMMAND_READY);
+ if (status < 0)
+ dev_err(chip->dev,
+ "%s() fail to write TPM_STS.commandReady\n", __func__);
+}
+
+/* read burstCount field from TPM_STS register
+ * return -1 on fail to read */
+static int i2c_nuvoton_get_burstcount(struct i2c_client *client,
+ struct tpm_chip *chip)
+{
+ unsigned long stop = jiffies + chip->vendor.timeout_d;
+ s32 status;
+ int burst_count = -1;
+ u8 data;
+
+ /* wait for burstcount to be non-zero */
+ do {
+ /* in I2C burstCount is 1 byte */
+ status = i2c_nuvoton_read_buf(client, TPM_BURST_COUNT, 1,
+ &data);
+ if (status > 0 && data > 0) {
+ burst_count = min_t(u8, TPM_I2C_MAX_BUF_SIZE, data);
+ break;
+ }
+ msleep(TPM_I2C_BUS_DELAY);
+ } while (time_before(jiffies, stop));
+
+ return burst_count;
+}
+
+/*
+ * WPCT301/NPCT501 SINT# supports only dataAvail
+ * any call to this function which is not waiting for dataAvail will
+ * set queue to NULL to avoid waiting for interrupt
+ */
+static bool i2c_nuvoton_check_status(struct tpm_chip *chip, u8 mask, u8 value)
+{
+ u8 status = i2c_nuvoton_read_status(chip);
+ return (status != TPM_STS_ERR_VAL) && ((status & mask) == value);
+}
+
+static int i2c_nuvoton_wait_for_stat(struct tpm_chip *chip, u8 mask, u8 value,
+ u32 timeout, wait_queue_head_t *queue)
+{
+ if (chip->vendor.irq && queue) {
+ s32 rc;
+ DEFINE_WAIT(wait);
+ struct priv_data *priv = chip->vendor.priv;
+ unsigned int cur_intrs = priv->intrs;
+
+ enable_irq(chip->vendor.irq);
+ rc = wait_event_interruptible_timeout(*queue,
+ cur_intrs != priv->intrs,
+ timeout);
+ if (rc > 0)
+ return 0;
+ /* At this point we know that the SINT pin is asserted, so we
+ * do not need to do i2c_nuvoton_check_status */
+ } else {
+ unsigned long ten_msec, stop;
+ bool status_valid;
+
+ /* check current status */
+ status_valid = i2c_nuvoton_check_status(chip, mask, value);
+ if (status_valid)
+ return 0;
+
+ /* use polling to wait for the event */
+ ten_msec = jiffies + msecs_to_jiffies(TPM_I2C_RETRY_DELAY_LONG);
+ stop = jiffies + timeout;
+ do {
+ if (time_before(jiffies, ten_msec))
+ msleep(TPM_I2C_RETRY_DELAY_SHORT);
+ else
+ msleep(TPM_I2C_RETRY_DELAY_LONG);
+ status_valid = i2c_nuvoton_check_status(chip, mask,
+ value);
+ if (status_valid)
+ return 0;
+ } while (time_before(jiffies, stop));
+ }
+ dev_err(chip->dev, "%s(%02x, %02x) -> timeout\n", __func__, mask,
+ value);
+ return -ETIMEDOUT;
+}
+
+/* wait for dataAvail field to be set in the TPM_STS register */
+static int i2c_nuvoton_wait_for_data_avail(struct tpm_chip *chip, u32 timeout,
+ wait_queue_head_t *queue)
+{
+ return i2c_nuvoton_wait_for_stat(chip,
+ TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ timeout, queue);
+}
+
+/* Read @count bytes into @buf from TPM_RD_FIFO register */
+static int i2c_nuvoton_recv_data(struct i2c_client *client,
+ struct tpm_chip *chip, u8 *buf, size_t count)
+{
+ s32 rc;
+ int burst_count, bytes2read, size = 0;
+
+ while (size < count &&
+ i2c_nuvoton_wait_for_data_avail(chip,
+ chip->vendor.timeout_c,
+ &chip->vendor.read_queue) == 0) {
+ burst_count = i2c_nuvoton_get_burstcount(client, chip);
+ if (burst_count < 0) {
+ dev_err(chip->dev,
+ "%s() fail to read burstCount=%d\n", __func__,
+ burst_count);
+ return -EIO;
+ }
+ bytes2read = min_t(size_t, burst_count, count - size);
+ rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_R,
+ bytes2read, &buf[size]);
+ if (rc < 0) {
+ dev_err(chip->dev,
+ "%s() fail on i2c_nuvoton_read_buf()=%d\n",
+ __func__, rc);
+ return -EIO;
+ }
+ dev_dbg(chip->dev, "%s(%d):", __func__, bytes2read);
+ size += bytes2read;
+ }
+
+ return size;
+}
+
+/* Read TPM command results */
+static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 *buf, size_t count)
+{
+ struct device *dev = chip->dev;
+ struct i2c_client *client = to_i2c_client(dev);
+ s32 rc;
+ int expected, status, burst_count, retries, size = 0;
+
+ if (count < TPM_HEADER_SIZE) {
+ i2c_nuvoton_ready(chip); /* return to idle */
+ dev_err(dev, "%s() count < header size\n", __func__);
+ return -EIO;
+ }
+ for (retries = 0; retries < TPM_RETRY; retries++) {
+ if (retries > 0) {
+ /* if this is not the first trial, set responseRetry */
+ i2c_nuvoton_write_status(client,
+ TPM_STS_RESPONSE_RETRY);
+ }
+ /*
+ * read first available (> 10 bytes), including:
+ * tag, paramsize, and result
+ */
+ status = i2c_nuvoton_wait_for_data_avail(
+ chip, chip->vendor.timeout_c, &chip->vendor.read_queue);
+ if (status != 0) {
+ dev_err(dev, "%s() timeout on dataAvail\n", __func__);
+ size = -ETIMEDOUT;
+ continue;
+ }
+ burst_count = i2c_nuvoton_get_burstcount(client, chip);
+ if (burst_count < 0) {
+ dev_err(dev, "%s() fail to get burstCount\n", __func__);
+ size = -EIO;
+ continue;
+ }
+ size = i2c_nuvoton_recv_data(client, chip, buf,
+ burst_count);
+ if (size < TPM_HEADER_SIZE) {
+ dev_err(dev, "%s() fail to read header\n", __func__);
+ size = -EIO;
+ continue;
+ }
+ /*
+ * convert number of expected bytes field from big endian 32 bit
+ * to machine native
+ */
+ expected = be32_to_cpu(*(__be32 *) (buf + 2));
+ if (expected > count) {
+ dev_err(dev, "%s() expected > count\n", __func__);
+ size = -EIO;
+ continue;
+ }
+ rc = i2c_nuvoton_recv_data(client, chip, &buf[size],
+ expected - size);
+ size += rc;
+ if (rc < 0 || size < expected) {
+ dev_err(dev, "%s() fail to read remainder of result\n",
+ __func__);
+ size = -EIO;
+ continue;
+ }
+ if (i2c_nuvoton_wait_for_stat(
+ chip, TPM_STS_VALID | TPM_STS_DATA_AVAIL,
+ TPM_STS_VALID, chip->vendor.timeout_c,
+ NULL)) {
+ dev_err(dev, "%s() error left over data\n", __func__);
+ size = -ETIMEDOUT;
+ continue;
+ }
+ break;
+ }
+ i2c_nuvoton_ready(chip);
+ dev_dbg(chip->dev, "%s() -> %d\n", __func__, size);
+ return size;
+}
+
+/*
+ * Send TPM command.
+ *
+ * If interrupts are used (signaled by an irq set in the vendor structure)
+ * tpm.c can skip polling for the data to be available as the interrupt is
+ * waited for here
+ */
+static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
+{
+ struct device *dev = chip->dev;
+ struct i2c_client *client = to_i2c_client(dev);
+ u32 ordinal;
+ size_t count = 0;
+ int burst_count, bytes2write, retries, rc = -EIO;
+
+ for (retries = 0; retries < TPM_RETRY; retries++) {
+ i2c_nuvoton_ready(chip);
+ if (i2c_nuvoton_wait_for_stat(chip, TPM_STS_COMMAND_READY,
+ TPM_STS_COMMAND_READY,
+ chip->vendor.timeout_b, NULL)) {
+ dev_err(dev, "%s() timeout on commandReady\n",
+ __func__);
+ rc = -EIO;
+ continue;
+ }
+ rc = 0;
+ while (count < len - 1) {
+ burst_count = i2c_nuvoton_get_burstcount(client,
+ chip);
+ if (burst_count < 0) {
+ dev_err(dev, "%s() fail get burstCount\n",
+ __func__);
+ rc = -EIO;
+ break;
+ }
+ bytes2write = min_t(size_t, burst_count,
+ len - 1 - count);
+ rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W,
+ bytes2write, &buf[count]);
+ if (rc < 0) {
+ dev_err(dev, "%s() fail i2cWriteBuf\n",
+ __func__);
+ break;
+ }
+ dev_dbg(dev, "%s(%d):", __func__, bytes2write);
+ count += bytes2write;
+ rc = i2c_nuvoton_wait_for_stat(chip,
+ TPM_STS_VALID |
+ TPM_STS_EXPECT,
+ TPM_STS_VALID |
+ TPM_STS_EXPECT,
+ chip->vendor.timeout_c,
+ NULL);
+ if (rc < 0) {
+ dev_err(dev, "%s() timeout on Expect\n",
+ __func__);
+ rc = -ETIMEDOUT;
+ break;
+ }
+ }
+ if (rc < 0)
+ continue;
+
+ /* write last byte */
+ rc = i2c_nuvoton_write_buf(client, TPM_DATA_FIFO_W, 1,
+ &buf[count]);
+ if (rc < 0) {
+ dev_err(dev, "%s() fail to write last byte\n",
+ __func__);
+ rc = -EIO;
+ continue;
+ }
+ dev_dbg(dev, "%s(last): %02x", __func__, buf[count]);
+ rc = i2c_nuvoton_wait_for_stat(chip,
+ TPM_STS_VALID | TPM_STS_EXPECT,
+ TPM_STS_VALID,
+ chip->vendor.timeout_c, NULL);
+ if (rc) {
+ dev_err(dev, "%s() timeout on Expect to clear\n",
+ __func__);
+ rc = -ETIMEDOUT;
+ continue;
+ }
+ break;
+ }
+ if (rc < 0) {
+ /* retries == TPM_RETRY */
+ i2c_nuvoton_ready(chip);
+ return rc;
+ }
+ /* execute the TPM command */
+ rc = i2c_nuvoton_write_status(client, TPM_STS_GO);
+ if (rc < 0) {
+ dev_err(dev, "%s() fail to write Go\n", __func__);
+ i2c_nuvoton_ready(chip);
+ return rc;
+ }
+ ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
+ rc = i2c_nuvoton_wait_for_data_avail(chip,
+ tpm_calc_ordinal_duration(chip,
+ ordinal),
+ &chip->vendor.read_queue);
+ if (rc) {
+ dev_err(dev, "%s() timeout command duration\n", __func__);
+ i2c_nuvoton_ready(chip);
+ return rc;
+ }
+
+ dev_dbg(dev, "%s() -> %zd\n", __func__, len);
+ return len;
+}
+
+static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
+{
+ return (status == TPM_STS_COMMAND_READY);
+}
+
+static const struct file_operations i2c_nuvoton_ops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .open = tpm_open,
+ .read = tpm_read,
+ .write = tpm_write,
+ .release = tpm_release,
+};
+
+static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
+static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
+static DEVICE_ATTR(enabled, S_IRUGO, tpm_show_enabled, NULL);
+static DEVICE_ATTR(active, S_IRUGO, tpm_show_active, NULL);
+static DEVICE_ATTR(owned, S_IRUGO, tpm_show_owned, NULL);
+static DEVICE_ATTR(temp_deactivated, S_IRUGO, tpm_show_temp_deactivated, NULL);
+static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
+static DEVICE_ATTR(cancel, S_IWUSR | S_IWGRP, NULL, tpm_store_cancel);
+static DEVICE_ATTR(durations, S_IRUGO, tpm_show_durations, NULL);
+static DEVICE_ATTR(timeouts, S_IRUGO, tpm_show_timeouts, NULL);
+
+static struct attribute *i2c_nuvoton_attrs[] = {
+ &dev_attr_pubek.attr,
+ &dev_attr_pcrs.attr,
+ &dev_attr_enabled.attr,
+ &dev_attr_active.attr,
+ &dev_attr_owned.attr,
+ &dev_attr_temp_deactivated.attr,
+ &dev_attr_caps.attr,
+ &dev_attr_cancel.attr,
+ &dev_attr_durations.attr,
+ &dev_attr_timeouts.attr,
+ NULL,
+};
+
+static struct attribute_group i2c_nuvoton_attr_grp = {
+ .attrs = i2c_nuvoton_attrs
+};
+
+static const struct tpm_vendor_specific tpm_i2c = {
+ .status = i2c_nuvoton_read_status,
+ .recv = i2c_nuvoton_recv,
+ .send = i2c_nuvoton_send,
+ .cancel = i2c_nuvoton_ready,
+ .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+ .req_canceled = i2c_nuvoton_req_canceled,
+ .attr_group = &i2c_nuvoton_attr_grp,
+ .miscdev.fops = &i2c_nuvoton_ops,
+};
+
+/* The only purpose for the handler is to signal to any waiting threads that
+ * the interrupt is currently being asserted. The driver does not do any
+ * processing triggered by interrupts, and the chip provides no way to mask at
+ * the source (plus that would be slow over I2C). Run the IRQ as a one-shot,
+ * this means it cannot be shared. */
+static irqreturn_t i2c_nuvoton_int_handler(int dummy, void *dev_id)
+{
+ struct tpm_chip *chip = dev_id;
+ struct priv_data *priv = chip->vendor.priv;
+
+ priv->intrs++;
+ wake_up(&chip->vendor.read_queue);
+ disable_irq_nosync(chip->vendor.irq);
+ return IRQ_HANDLED;
+}
+
+static int get_vid(struct i2c_client *client, u32 *res)
+{
+ static const u8 vid_did_rid_value[] = { 0x50, 0x10, 0xfe };
+ u32 temp;
+ s32 rc;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ return -ENODEV;
+ rc = i2c_nuvoton_read_buf(client, TPM_VID_DID_RID, 4, (u8 *)&temp);
+ if (rc < 0)
+ return rc;
+
+ /* check WPCT301 values - ignore RID */
+ if (memcmp(&temp, vid_did_rid_value, sizeof(vid_did_rid_value))) {
+ /*
+ * f/w rev 2.81 has an issue where the VID_DID_RID is not
+ * reporting the right value. so give it another chance at
+ * offset 0x20 (FIFO_W).
+ */
+ rc = i2c_nuvoton_read_buf(client, TPM_DATA_FIFO_W, 4,
+ (u8 *) (&temp));
+ if (rc < 0)
+ return rc;
+
+ /* check WPCT301 values - ignore RID */
+ if (memcmp(&temp, vid_did_rid_value,
+ sizeof(vid_did_rid_value)))
+ return -ENODEV;
+ }
+
+ *res = temp;
+ return 0;
+}
+
+static int i2c_nuvoton_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int rc;
+ struct tpm_chip *chip;
+ struct device *dev = &client->dev;
+ u32 vid = 0;
+
+ rc = get_vid(client, &vid);
+ if (rc)
+ return rc;
+
+ dev_info(dev, "VID: %04X DID: %02X RID: %02X\n", (u16) vid,
+ (u8) (vid >> 16), (u8) (vid >> 24));
+
+ chip = tpm_register_hardware(dev, &tpm_i2c);
+ if (!chip) {
+ dev_err(dev, "%s() error in tpm_register_hardware\n", __func__);
+ return -ENODEV;
+ }
+
+ chip->vendor.priv = devm_kzalloc(dev, sizeof(struct priv_data),
+ GFP_KERNEL);
+ init_waitqueue_head(&chip->vendor.read_queue);
+ init_waitqueue_head(&chip->vendor.int_queue);
+
+ /* Default timeouts */
+ chip->vendor.timeout_a = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
+ chip->vendor.timeout_b = msecs_to_jiffies(TPM_I2C_LONG_TIMEOUT);
+ chip->vendor.timeout_c = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
+ chip->vendor.timeout_d = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
+
+ /*
+ * I2C intfcaps (interrupt capabilitieis) in the chip are hard coded to:
+ * TPM_INTF_INT_LEVEL_LOW | TPM_INTF_DATA_AVAIL_INT
+ * The IRQ should be set in the i2c_board_info (which is done
+ * automatically in of_i2c_register_devices, for device tree users */
+ chip->vendor.irq = client->irq;
+
+ if (chip->vendor.irq) {
+ dev_dbg(dev, "%s() chip-vendor.irq\n", __func__);
+ rc = devm_request_irq(dev, chip->vendor.irq,
+ i2c_nuvoton_int_handler,
+ IRQF_TRIGGER_LOW,
+ chip->vendor.miscdev.name,
+ chip);
+ if (rc) {
+ dev_err(dev, "%s() Unable to request irq: %d for use\n",
+ __func__, chip->vendor.irq);
+ chip->vendor.irq = 0;
+ } else {
+ /* Clear any pending interrupt */
+ i2c_nuvoton_ready(chip);
+ /* - wait for TPM_STS==0xA0 (stsValid, commandReady) */
+ rc = i2c_nuvoton_wait_for_stat(chip,
+ TPM_STS_COMMAND_READY,
+ TPM_STS_COMMAND_READY,
+ chip->vendor.timeout_b,
+ NULL);
+ if (rc == 0) {
+ /*
+ * TIS is in ready state
+ * write dummy byte to enter reception state
+ * TPM_DATA_FIFO_W <- rc (0)
+ */
+ rc = i2c_nuvoton_write_buf(client,
+ TPM_DATA_FIFO_W,
+ 1, (u8 *) (&rc));
+ if (rc < 0)
+ goto out_err;
+ /* TPM_STS <- 0x40 (commandReady) */
+ i2c_nuvoton_ready(chip);
+ } else {
+ /*
+ * timeout_b reached - command was
+ * aborted. TIS should now be in idle state -
+ * only TPM_STS_VALID should be set
+ */
+ if (i2c_nuvoton_read_status(chip) !=
+ TPM_STS_VALID) {
+ rc = -EIO;
+ goto out_err;
+ }
+ }
+ }
+ }
+
+ if (tpm_get_timeouts(chip)) {
+ rc = -ENODEV;
+ goto out_err;
+ }
+
+ if (tpm_do_selftest(chip)) {
+ rc = -ENODEV;
+ goto out_err;
+ }
+
+ return 0;
+
+out_err:
+ tpm_dev_vendor_release(chip);
+ tpm_remove_hardware(chip->dev);
+ return rc;
+}
+
+static int i2c_nuvoton_remove(struct i2c_client *client)
+{
+ struct device *dev = &(client->dev);
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ if (chip)
+ tpm_dev_vendor_release(chip);
+ tpm_remove_hardware(dev);
+ kfree(chip);
+ return 0;
+}
+
+
+static const struct i2c_device_id i2c_nuvoton_id[] = {
+ {I2C_DRIVER_NAME, 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, i2c_nuvoton_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id i2c_nuvoton_of_match[] = {
+ {.compatible = "nuvoton,npct501"},
+ {.compatible = "winbond,wpct301"},
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_nuvoton_of_match);
+#endif
+
+static SIMPLE_DEV_PM_OPS(i2c_nuvoton_pm_ops, tpm_pm_suspend, tpm_pm_resume);
+
+static struct i2c_driver i2c_nuvoton_driver = {
+ .id_table = i2c_nuvoton_id,
+ .probe = i2c_nuvoton_probe,
+ .remove = i2c_nuvoton_remove,
+ .driver = {
+ .name = I2C_DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .pm = &i2c_nuvoton_pm_ops,
+ .of_match_table = of_match_ptr(i2c_nuvoton_of_match),
+ },
+};
+
+module_i2c_driver(i2c_nuvoton_driver);
+
+MODULE_AUTHOR("Dan Morav (dan.morav@nuvoton.com)");
+MODULE_DESCRIPTION("Nuvoton TPM I2C Driver");
+MODULE_LICENSE("GPL");