diff options
Diffstat (limited to 'drivers/char/tpm/st33zp24/st33zp24.c')
| -rw-r--r-- | drivers/char/tpm/st33zp24/st33zp24.c | 698 |
1 files changed, 698 insertions, 0 deletions
diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c new file mode 100644 index 000000000000..8d626784cd8d --- /dev/null +++ b/drivers/char/tpm/st33zp24/st33zp24.c @@ -0,0 +1,698 @@ +/* + * STMicroelectronics TPM Linux driver for TPM ST33ZP24 + * Copyright (C) 2009 - 2015 STMicroelectronics + * + * 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/>. + */ + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/wait.h> +#include <linux/freezer.h> +#include <linux/string.h> +#include <linux/interrupt.h> +#include <linux/gpio.h> +#include <linux/sched.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/slab.h> + +#include "../tpm.h" +#include "st33zp24.h" + +#define TPM_ACCESS 0x0 +#define TPM_STS 0x18 +#define TPM_DATA_FIFO 0x24 +#define TPM_INTF_CAPABILITY 0x14 +#define TPM_INT_STATUS 0x10 +#define TPM_INT_ENABLE 0x08 + +#define LOCALITY0 0 + +enum st33zp24_access { + TPM_ACCESS_VALID = 0x80, + TPM_ACCESS_ACTIVE_LOCALITY = 0x20, + TPM_ACCESS_REQUEST_PENDING = 0x04, + TPM_ACCESS_REQUEST_USE = 0x02, +}; + +enum st33zp24_status { + TPM_STS_VALID = 0x80, + TPM_STS_COMMAND_READY = 0x40, + TPM_STS_GO = 0x20, + TPM_STS_DATA_AVAIL = 0x10, + TPM_STS_DATA_EXPECT = 0x08, +}; + +enum st33zp24_int_flags { + TPM_GLOBAL_INT_ENABLE = 0x80, + TPM_INTF_CMD_READY_INT = 0x080, + TPM_INTF_FIFO_AVALAIBLE_INT = 0x040, + TPM_INTF_WAKE_UP_READY_INT = 0x020, + TPM_INTF_LOCALITY_CHANGE_INT = 0x004, + TPM_INTF_STS_VALID_INT = 0x002, + TPM_INTF_DATA_AVAIL_INT = 0x001, +}; + +enum tis_defaults { + TIS_SHORT_TIMEOUT = 750, + TIS_LONG_TIMEOUT = 2000, +}; + +struct st33zp24_dev { + struct tpm_chip *chip; + void *phy_id; + const struct st33zp24_phy_ops *ops; + u32 intrs; + int io_lpcpd; +}; + +/* + * clear_interruption clear the pending interrupt. + * @param: tpm_dev, the tpm device device. + * @return: the interrupt status value. + */ +static u8 clear_interruption(struct st33zp24_dev *tpm_dev) +{ + u8 interrupt; + + tpm_dev->ops->recv(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1); + tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1); + return interrupt; +} /* clear_interruption() */ + +/* + * st33zp24_cancel, cancel the current command execution or + * set STS to COMMAND READY. + * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h + */ +static void st33zp24_cancel(struct tpm_chip *chip) +{ + struct st33zp24_dev *tpm_dev; + u8 data; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + data = TPM_STS_COMMAND_READY; + tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1); +} /* st33zp24_cancel() */ + +/* + * st33zp24_status return the TPM_STS register + * @param: chip, the tpm chip description + * @return: the TPM_STS register value. + */ +static u8 st33zp24_status(struct tpm_chip *chip) +{ + struct st33zp24_dev *tpm_dev; + u8 data; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS, &data, 1); + return data; +} /* st33zp24_status() */ + +/* + * check_locality if the locality is active + * @param: chip, the tpm chip description + * @return: the active locality or -EACCESS. + */ +static int check_locality(struct tpm_chip *chip) +{ + struct st33zp24_dev *tpm_dev; + u8 data; + u8 status; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_ACCESS, &data, 1); + if (status && (data & + (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) == + (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) + return chip->vendor.locality; + + return -EACCES; +} /* check_locality() */ + +/* + * request_locality request the TPM locality + * @param: chip, the chip description + * @return: the active locality or negative value. + */ +static int request_locality(struct tpm_chip *chip) +{ + unsigned long stop; + long ret; + struct st33zp24_dev *tpm_dev; + u8 data; + + if (check_locality(chip) == chip->vendor.locality) + return chip->vendor.locality; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + data = TPM_ACCESS_REQUEST_USE; + ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1); + if (ret < 0) + return ret; + + stop = jiffies + chip->vendor.timeout_a; + + /* Request locality is usually effective after the request */ + do { + if (check_locality(chip) >= 0) + return chip->vendor.locality; + msleep(TPM_TIMEOUT); + } while (time_before(jiffies, stop)); + + /* could not get locality */ + return -EACCES; +} /* request_locality() */ + +/* + * release_locality release the active locality + * @param: chip, the tpm chip description. + */ +static void release_locality(struct tpm_chip *chip) +{ + struct st33zp24_dev *tpm_dev; + u8 data; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + data = TPM_ACCESS_ACTIVE_LOCALITY; + + tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1); +} + +/* + * get_burstcount return the burstcount value + * @param: chip, the chip description + * return: the burstcount or negative value. + */ +static int get_burstcount(struct tpm_chip *chip) +{ + unsigned long stop; + int burstcnt, status; + u8 tpm_reg, temp; + struct st33zp24_dev *tpm_dev; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + stop = jiffies + chip->vendor.timeout_d; + do { + tpm_reg = TPM_STS + 1; + status = tpm_dev->ops->recv(tpm_dev->phy_id, tpm_reg, &temp, 1); + if (status < 0) + return -EBUSY; + + tpm_reg = TPM_STS + 2; + burstcnt = temp; + status = tpm_dev->ops->recv(tpm_dev->phy_id, tpm_reg, &temp, 1); + if (status < 0) + return -EBUSY; + + burstcnt |= temp << 8; + if (burstcnt) + return burstcnt; + msleep(TPM_TIMEOUT); + } while (time_before(jiffies, stop)); + return -EBUSY; +} /* get_burstcount() */ + + +/* + * wait_for_tpm_stat_cond + * @param: chip, chip description + * @param: mask, expected mask value + * @param: check_cancel, does the command expected to be canceled ? + * @param: canceled, did we received a cancel request ? + * @return: true if status == mask or if the command is canceled. + * false in other cases. + */ +static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, + bool check_cancel, bool *canceled) +{ + u8 status = chip->ops->status(chip); + + *canceled = false; + if ((status & mask) == mask) + return true; + if (check_cancel && chip->ops->req_canceled(chip, status)) { + *canceled = true; + return true; + } + return false; +} + +/* + * wait_for_stat wait for a TPM_STS value + * @param: chip, the tpm chip description + * @param: mask, the value mask to wait + * @param: timeout, the timeout + * @param: queue, the wait queue. + * @param: check_cancel, does the command can be cancelled ? + * @return: the tpm status, 0 if success, -ETIME if timeout is reached. + */ +static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, + wait_queue_head_t *queue, bool check_cancel) +{ + unsigned long stop; + int ret = 0; + bool canceled = false; + bool condition; + u32 cur_intrs; + u8 status; + struct st33zp24_dev *tpm_dev; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + /* check current status */ + status = st33zp24_status(chip); + if ((status & mask) == mask) + return 0; + + stop = jiffies + timeout; + + if (chip->vendor.irq) { + cur_intrs = tpm_dev->intrs; + clear_interruption(tpm_dev); + enable_irq(chip->vendor.irq); + + do { + if (ret == -ERESTARTSYS && freezing(current)) + clear_thread_flag(TIF_SIGPENDING); + + timeout = stop - jiffies; + if ((long) timeout <= 0) + return -1; + + ret = wait_event_interruptible_timeout(*queue, + cur_intrs != tpm_dev->intrs, + timeout); + clear_interruption(tpm_dev); + condition = wait_for_tpm_stat_cond(chip, mask, + check_cancel, &canceled); + if (ret >= 0 && condition) { + if (canceled) + return -ECANCELED; + return 0; + } + } while (ret == -ERESTARTSYS && freezing(current)); + + disable_irq_nosync(chip->vendor.irq); + + } else { + do { + msleep(TPM_TIMEOUT); + status = chip->ops->status(chip); + if ((status & mask) == mask) + return 0; + } while (time_before(jiffies, stop)); + } + + return -ETIME; +} /* wait_for_stat() */ + +/* + * recv_data receive data + * @param: chip, the tpm chip description + * @param: buf, the buffer where the data are received + * @param: count, the number of data to receive + * @return: the number of bytes read from TPM FIFO. + */ +static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) +{ + int size = 0, burstcnt, len, ret; + struct st33zp24_dev *tpm_dev; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + while (size < count && + wait_for_stat(chip, + TPM_STS_DATA_AVAIL | TPM_STS_VALID, + chip->vendor.timeout_c, + &chip->vendor.read_queue, true) == 0) { + burstcnt = get_burstcount(chip); + if (burstcnt < 0) + return burstcnt; + len = min_t(int, burstcnt, count - size); + ret = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_DATA_FIFO, + buf + size, len); + if (ret < 0) + return ret; + + size += len; + } + return size; +} + +/* + * tpm_ioserirq_handler the serirq irq handler + * @param: irq, the tpm chip description + * @param: dev_id, the description of the chip + * @return: the status of the handler. + */ +static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id) +{ + struct tpm_chip *chip = dev_id; + struct st33zp24_dev *tpm_dev; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + tpm_dev->intrs++; + wake_up_interruptible(&chip->vendor.read_queue); + disable_irq_nosync(chip->vendor.irq); + + return IRQ_HANDLED; +} /* tpm_ioserirq_handler() */ + +/* + * st33zp24_send send TPM commands through the I2C bus. + * + * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h + * @param: buf, the buffer to send. + * @param: count, the number of bytes to send. + * @return: In case of success the number of bytes sent. + * In other case, a < 0 value describing the issue. + */ +static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf, + size_t len) +{ + u32 status, i, size, ordinal; + int burstcnt = 0; + int ret; + u8 data; + struct st33zp24_dev *tpm_dev; + + if (!chip) + return -EBUSY; + if (len < TPM_HEADER_SIZE) + return -EBUSY; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + ret = request_locality(chip); + if (ret < 0) + return ret; + + status = st33zp24_status(chip); + if ((status & TPM_STS_COMMAND_READY) == 0) { + st33zp24_cancel(chip); + if (wait_for_stat + (chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b, + &chip->vendor.read_queue, false) < 0) { + ret = -ETIME; + goto out_err; + } + } + + for (i = 0; i < len - 1;) { + burstcnt = get_burstcount(chip); + if (burstcnt < 0) + return burstcnt; + size = min_t(int, len - i - 1, burstcnt); + ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO, + buf + i, size); + if (ret < 0) + goto out_err; + + i += size; + } + + status = st33zp24_status(chip); + if ((status & TPM_STS_DATA_EXPECT) == 0) { + ret = -EIO; + goto out_err; + } + + ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO, + buf + len - 1, 1); + if (ret < 0) + goto out_err; + + status = st33zp24_status(chip); + if ((status & TPM_STS_DATA_EXPECT) != 0) { + ret = -EIO; + goto out_err; + } + + data = TPM_STS_GO; + ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1); + if (ret < 0) + goto out_err; + + if (chip->vendor.irq) { + ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); + + ret = wait_for_stat(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, + tpm_calc_ordinal_duration(chip, ordinal), + &chip->vendor.read_queue, false); + if (ret < 0) + goto out_err; + } + + return len; +out_err: + st33zp24_cancel(chip); + release_locality(chip); + return ret; +} + +/* + * st33zp24_recv received TPM response through TPM phy. + * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h. + * @param: buf, the buffer to store datas. + * @param: count, the number of bytes to send. + * @return: In case of success the number of bytes received. + * In other case, a < 0 value describing the issue. + */ +static int st33zp24_recv(struct tpm_chip *chip, unsigned char *buf, + size_t count) +{ + int size = 0; + int expected; + + if (!chip) + return -EBUSY; + + if (count < TPM_HEADER_SIZE) { + size = -EIO; + goto out; + } + + size = recv_data(chip, buf, TPM_HEADER_SIZE); + if (size < TPM_HEADER_SIZE) { + dev_err(&chip->dev, "Unable to read header\n"); + goto out; + } + + expected = be32_to_cpu(*(__be32 *)(buf + 2)); + if (expected > count) { + size = -EIO; + goto out; + } + + size += recv_data(chip, &buf[TPM_HEADER_SIZE], + expected - TPM_HEADER_SIZE); + if (size < expected) { + dev_err(&chip->dev, "Unable to read remainder of result\n"); + size = -ETIME; + } + +out: + st33zp24_cancel(chip); + release_locality(chip); + return size; +} + +/* + * st33zp24_req_canceled + * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h. + * @param: status, the TPM status. + * @return: Does TPM ready to compute a new command ? true. + */ +static bool st33zp24_req_canceled(struct tpm_chip *chip, u8 status) +{ + return (status == TPM_STS_COMMAND_READY); +} + +static const struct tpm_class_ops st33zp24_tpm = { + .send = st33zp24_send, + .recv = st33zp24_recv, + .cancel = st33zp24_cancel, + .status = st33zp24_status, + .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID, + .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID, + .req_canceled = st33zp24_req_canceled, +}; + +/* + * st33zp24_probe initialize the TPM device + * @param: client, the i2c_client drescription (TPM I2C description). + * @param: id, the i2c_device_id struct. + * @return: 0 in case of success. + * -1 in other case. + */ +int st33zp24_probe(void *phy_id, const struct st33zp24_phy_ops *ops, + struct device *dev, int irq, int io_lpcpd) +{ + int ret; + u8 intmask = 0; + struct tpm_chip *chip; + struct st33zp24_dev *tpm_dev; + + chip = tpmm_chip_alloc(dev, &st33zp24_tpm); + if (IS_ERR(chip)) + return PTR_ERR(chip); + + tpm_dev = devm_kzalloc(dev, sizeof(struct st33zp24_dev), + GFP_KERNEL); + if (!tpm_dev) + return -ENOMEM; + + TPM_VPRIV(chip) = tpm_dev; + tpm_dev->phy_id = phy_id; + tpm_dev->ops = ops; + + chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT); + chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT); + chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT); + chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT); + + chip->vendor.locality = LOCALITY0; + + if (irq) { + /* INTERRUPT Setup */ + init_waitqueue_head(&chip->vendor.read_queue); + tpm_dev->intrs = 0; + + if (request_locality(chip) != LOCALITY0) { + ret = -ENODEV; + goto _tpm_clean_answer; + } + + clear_interruption(tpm_dev); + ret = devm_request_irq(dev, irq, tpm_ioserirq_handler, + IRQF_TRIGGER_HIGH, "TPM SERIRQ management", + chip); + if (ret < 0) { + dev_err(&chip->dev, "TPM SERIRQ signals %d not available\n", + irq); + goto _tpm_clean_answer; + } + + intmask |= TPM_INTF_CMD_READY_INT + | TPM_INTF_STS_VALID_INT + | TPM_INTF_DATA_AVAIL_INT; + + ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_ENABLE, + &intmask, 1); + if (ret < 0) + goto _tpm_clean_answer; + + intmask = TPM_GLOBAL_INT_ENABLE; + ret = tpm_dev->ops->send(tpm_dev->phy_id, (TPM_INT_ENABLE + 3), + &intmask, 1); + if (ret < 0) + goto _tpm_clean_answer; + + chip->vendor.irq = irq; + + disable_irq_nosync(chip->vendor.irq); + + tpm_gen_interrupt(chip); + } + + tpm_get_timeouts(chip); + tpm_do_selftest(chip); + + return tpm_chip_register(chip); +_tpm_clean_answer: + dev_info(&chip->dev, "TPM initialization fail\n"); + return ret; +} +EXPORT_SYMBOL(st33zp24_probe); + +/* + * st33zp24_remove remove the TPM device + * @param: tpm_data, the tpm phy. + * @return: 0 in case of success. + */ +int st33zp24_remove(struct tpm_chip *chip) +{ + tpm_chip_unregister(chip); + return 0; +} +EXPORT_SYMBOL(st33zp24_remove); + +#ifdef CONFIG_PM_SLEEP +/* + * st33zp24_pm_suspend suspend the TPM device + * @param: tpm_data, the tpm phy. + * @param: mesg, the power management message. + * @return: 0 in case of success. + */ +int st33zp24_pm_suspend(struct device *dev) +{ + struct tpm_chip *chip = dev_get_drvdata(dev); + struct st33zp24_dev *tpm_dev; + int ret = 0; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + if (gpio_is_valid(tpm_dev->io_lpcpd)) + gpio_set_value(tpm_dev->io_lpcpd, 0); + else + ret = tpm_pm_suspend(dev); + + return ret; +} /* st33zp24_pm_suspend() */ +EXPORT_SYMBOL(st33zp24_pm_suspend); + +/* + * st33zp24_pm_resume resume the TPM device + * @param: tpm_data, the tpm phy. + * @return: 0 in case of success. + */ +int st33zp24_pm_resume(struct device *dev) +{ + struct tpm_chip *chip = dev_get_drvdata(dev); + struct st33zp24_dev *tpm_dev; + int ret = 0; + + tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip); + + if (gpio_is_valid(tpm_dev->io_lpcpd)) { + gpio_set_value(tpm_dev->io_lpcpd, 1); + ret = wait_for_stat(chip, + TPM_STS_VALID, chip->vendor.timeout_b, + &chip->vendor.read_queue, false); + } else { + ret = tpm_pm_resume(dev); + if (!ret) + tpm_do_selftest(chip); + } + return ret; +} /* st33zp24_pm_resume() */ +EXPORT_SYMBOL(st33zp24_pm_resume); +#endif + +MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)"); +MODULE_DESCRIPTION("ST33ZP24 TPM 1.2 driver"); +MODULE_VERSION("1.3.0"); +MODULE_LICENSE("GPL"); |