mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-14 06:24:53 +08:00
be6f48a7c8
After commitb8a1a4cd5a
("i2c: Provide a temporary .probe_new() call-back type"), all drivers being converted to .probe_new() and then03c835f498
("i2c: Switch .probe() to not take an id parameter") convert back to (the new) .probe() to be able to eventually drop .probe_new() from struct i2c_driver. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
220 lines
5.8 KiB
C
220 lines
5.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* ATMEL I2C TPM AT97SC3204T
|
|
*
|
|
* Copyright (C) 2012 V Lab Technologies
|
|
* Teddy Reed <teddy@prosauce.org>
|
|
* Copyright (C) 2013, Obsidian Research Corp.
|
|
* Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
|
|
* Device driver for ATMEL I2C TPMs.
|
|
*
|
|
* Teddy Reed determined the basic I2C command flow, unlike other I2C TPM
|
|
* devices the raw TCG formatted TPM command data is written via I2C and then
|
|
* raw TCG formatted TPM command data is returned via I2C.
|
|
*
|
|
* TGC status/locality/etc functions seen in the LPC implementation do not
|
|
* seem to be present.
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/i2c.h>
|
|
#include "tpm.h"
|
|
|
|
#define I2C_DRIVER_NAME "tpm_i2c_atmel"
|
|
|
|
#define TPM_I2C_SHORT_TIMEOUT 750 /* ms */
|
|
#define TPM_I2C_LONG_TIMEOUT 2000 /* 2 sec */
|
|
|
|
#define ATMEL_STS_OK 1
|
|
|
|
struct priv_data {
|
|
size_t len;
|
|
/* This is the amount we read on the first try. 25 was chosen to fit a
|
|
* fair number of read responses in the buffer so a 2nd retry can be
|
|
* avoided in small message cases. */
|
|
u8 buffer[sizeof(struct tpm_header) + 25];
|
|
};
|
|
|
|
static int i2c_atmel_send(struct tpm_chip *chip, u8 *buf, size_t len)
|
|
{
|
|
struct priv_data *priv = dev_get_drvdata(&chip->dev);
|
|
struct i2c_client *client = to_i2c_client(chip->dev.parent);
|
|
s32 status;
|
|
|
|
priv->len = 0;
|
|
|
|
if (len <= 2)
|
|
return -EIO;
|
|
|
|
status = i2c_master_send(client, buf, len);
|
|
|
|
dev_dbg(&chip->dev,
|
|
"%s(buf=%*ph len=%0zx) -> sts=%d\n", __func__,
|
|
(int)min_t(size_t, 64, len), buf, len, status);
|
|
|
|
if (status < 0)
|
|
return status;
|
|
|
|
/* The upper layer does not support incomplete sends. */
|
|
if (status != len)
|
|
return -E2BIG;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int i2c_atmel_recv(struct tpm_chip *chip, u8 *buf, size_t count)
|
|
{
|
|
struct priv_data *priv = dev_get_drvdata(&chip->dev);
|
|
struct i2c_client *client = to_i2c_client(chip->dev.parent);
|
|
struct tpm_header *hdr = (struct tpm_header *)priv->buffer;
|
|
u32 expected_len;
|
|
int rc;
|
|
|
|
if (priv->len == 0)
|
|
return -EIO;
|
|
|
|
/* Get the message size from the message header, if we didn't get the
|
|
* whole message in read_status then we need to re-read the
|
|
* message. */
|
|
expected_len = be32_to_cpu(hdr->length);
|
|
if (expected_len > count)
|
|
return -ENOMEM;
|
|
|
|
if (priv->len >= expected_len) {
|
|
dev_dbg(&chip->dev,
|
|
"%s early(buf=%*ph count=%0zx) -> ret=%d\n", __func__,
|
|
(int)min_t(size_t, 64, expected_len), buf, count,
|
|
expected_len);
|
|
memcpy(buf, priv->buffer, expected_len);
|
|
return expected_len;
|
|
}
|
|
|
|
rc = i2c_master_recv(client, buf, expected_len);
|
|
dev_dbg(&chip->dev,
|
|
"%s reread(buf=%*ph count=%0zx) -> ret=%d\n", __func__,
|
|
(int)min_t(size_t, 64, expected_len), buf, count,
|
|
expected_len);
|
|
return rc;
|
|
}
|
|
|
|
static void i2c_atmel_cancel(struct tpm_chip *chip)
|
|
{
|
|
dev_err(&chip->dev, "TPM operation cancellation was requested, but is not supported");
|
|
}
|
|
|
|
static u8 i2c_atmel_read_status(struct tpm_chip *chip)
|
|
{
|
|
struct priv_data *priv = dev_get_drvdata(&chip->dev);
|
|
struct i2c_client *client = to_i2c_client(chip->dev.parent);
|
|
int rc;
|
|
|
|
/* The TPM fails the I2C read until it is ready, so we do the entire
|
|
* transfer here and buffer it locally. This way the common code can
|
|
* properly handle the timeouts. */
|
|
priv->len = 0;
|
|
memset(priv->buffer, 0, sizeof(priv->buffer));
|
|
|
|
|
|
/* Once the TPM has completed the command the command remains readable
|
|
* until another command is issued. */
|
|
rc = i2c_master_recv(client, priv->buffer, sizeof(priv->buffer));
|
|
dev_dbg(&chip->dev,
|
|
"%s: sts=%d", __func__, rc);
|
|
if (rc <= 0)
|
|
return 0;
|
|
|
|
priv->len = rc;
|
|
|
|
return ATMEL_STS_OK;
|
|
}
|
|
|
|
static bool i2c_atmel_req_canceled(struct tpm_chip *chip, u8 status)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static const struct tpm_class_ops i2c_atmel = {
|
|
.flags = TPM_OPS_AUTO_STARTUP,
|
|
.status = i2c_atmel_read_status,
|
|
.recv = i2c_atmel_recv,
|
|
.send = i2c_atmel_send,
|
|
.cancel = i2c_atmel_cancel,
|
|
.req_complete_mask = ATMEL_STS_OK,
|
|
.req_complete_val = ATMEL_STS_OK,
|
|
.req_canceled = i2c_atmel_req_canceled,
|
|
};
|
|
|
|
static int i2c_atmel_probe(struct i2c_client *client)
|
|
{
|
|
struct tpm_chip *chip;
|
|
struct device *dev = &client->dev;
|
|
struct priv_data *priv;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
chip = tpmm_chip_alloc(dev, &i2c_atmel);
|
|
if (IS_ERR(chip))
|
|
return PTR_ERR(chip);
|
|
|
|
priv = devm_kzalloc(dev, sizeof(struct priv_data), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
/* Default timeouts */
|
|
chip->timeout_a = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
|
|
chip->timeout_b = msecs_to_jiffies(TPM_I2C_LONG_TIMEOUT);
|
|
chip->timeout_c = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
|
|
chip->timeout_d = msecs_to_jiffies(TPM_I2C_SHORT_TIMEOUT);
|
|
|
|
dev_set_drvdata(&chip->dev, priv);
|
|
|
|
/* There is no known way to probe for this device, and all version
|
|
* information seems to be read via TPM commands. Thus we rely on the
|
|
* TPM startup process in the common code to detect the device. */
|
|
|
|
return tpm_chip_register(chip);
|
|
}
|
|
|
|
static void i2c_atmel_remove(struct i2c_client *client)
|
|
{
|
|
struct device *dev = &(client->dev);
|
|
struct tpm_chip *chip = dev_get_drvdata(dev);
|
|
tpm_chip_unregister(chip);
|
|
}
|
|
|
|
static const struct i2c_device_id i2c_atmel_id[] = {
|
|
{I2C_DRIVER_NAME, 0},
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, i2c_atmel_id);
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id i2c_atmel_of_match[] = {
|
|
{.compatible = "atmel,at97sc3204t"},
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, i2c_atmel_of_match);
|
|
#endif
|
|
|
|
static SIMPLE_DEV_PM_OPS(i2c_atmel_pm_ops, tpm_pm_suspend, tpm_pm_resume);
|
|
|
|
static struct i2c_driver i2c_atmel_driver = {
|
|
.id_table = i2c_atmel_id,
|
|
.probe = i2c_atmel_probe,
|
|
.remove = i2c_atmel_remove,
|
|
.driver = {
|
|
.name = I2C_DRIVER_NAME,
|
|
.pm = &i2c_atmel_pm_ops,
|
|
.of_match_table = of_match_ptr(i2c_atmel_of_match),
|
|
},
|
|
};
|
|
|
|
module_i2c_driver(i2c_atmel_driver);
|
|
|
|
MODULE_AUTHOR("Jason Gunthorpe <jgunthorpe@obsidianresearch.com>");
|
|
MODULE_DESCRIPTION("Atmel TPM I2C Driver");
|
|
MODULE_LICENSE("GPL");
|