| Message ID | 1422220293-21005-4-git-send-email-christophe-h.ricard@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am Sonntag, 25. Januar 2015, 22:11:32 schrieb Christophe Ricard: > st33zp24 TIS 1.2 support also SPI. It is using a proprietary protocol to > transport TIS data. > > Reviewed-by: Jason Gunthorpe <jason.gunthorpe@obsidianresearch.com> > Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com> > --- > drivers/char/tpm/st33zp24/Kconfig | 10 + > drivers/char/tpm/st33zp24/Makefile | 3 + > drivers/char/tpm/st33zp24/spi.c | 386 > +++++++++++++++++++++++++++++++++++++ 3 files changed, 399 insertions(+) > create mode 100644 drivers/char/tpm/st33zp24/spi.c > > diff --git a/drivers/char/tpm/st33zp24/Kconfig > b/drivers/char/tpm/st33zp24/Kconfig index 51dcef5..09cb7278 100644 > --- a/drivers/char/tpm/st33zp24/Kconfig > +++ b/drivers/char/tpm/st33zp24/Kconfig > @@ -18,3 +18,13 @@ config TCG_TIS_ST33ZP24_I2C > ST33ZP24 with i2c interface. > To compile this driver as a module, choose M here; the module will be > called tpm_st33zp24_i2c. > + > +config TCG_TIS_ST33ZP24_SPI > + tristate "TPM 1.2 ST33ZP24 SPI support" > + depends on TCG_TIS_ST33ZP24 > + depends on SPI > + ---help--- > + This module adds support for the STMicroelectronics TPM security chip > + ST33ZP24 with spi interface. > + To compile this driver as a module, choose M here; the module will be > + called tpm_st33zp24_spi. > diff --git a/drivers/char/tpm/st33zp24/Makefile > b/drivers/char/tpm/st33zp24/Makefile index 414497f..74a722e 100644 > --- a/drivers/char/tpm/st33zp24/Makefile > +++ b/drivers/char/tpm/st33zp24/Makefile > @@ -7,3 +7,6 @@ obj-$(CONFIG_TCG_TIS_ST33ZP24) += tpm_st33zp24.o > > tpm_st33zp24_i2c-objs = i2c.o > obj-$(CONFIG_TCG_TIS_ST33ZP24_I2C) += tpm_st33zp24_i2c.o > + > +tpm_st33zp24_spi-objs = spi.o > +obj-$(CONFIG_TCG_TIS_ST33ZP24_SPI) += tpm_st33zp24_spi.o > diff --git a/drivers/char/tpm/st33zp24/spi.c > b/drivers/char/tpm/st33zp24/spi.c new file mode 100644 > index 0000000..d481478 > --- /dev/null > +++ b/drivers/char/tpm/st33zp24/spi.c > @@ -0,0 +1,386 @@ > +/* > + * STMicroelectronics TPM SPI 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/spi/spi.h> > +#include <linux/gpio.h> > +#include <linux/of_irq.h> > +#include <linux/of_gpio.h> > +#include <linux/tpm.h> > +#include <linux/platform_data/st33zp24.h> > + > +#include "st33zp24.h" > + > +#define TPM_DATA_FIFO 0x24 > +#define TPM_INTF_CAPABILITY 0x14 > + > +#define TPM_DUMMY_BYTE 0x00 > +#define TPM_WRITE_DIRECTION 0x80 > +#define TPM_BUFSIZE 2048 see previous email :) > + > +#define MAX_SPI_LATENCY 15 > +#define LOCALITY0 0 > + > +#define ST33ZP24_OK 0x5A > +#define ST33ZP24_UNDEFINED_ERR 0x80 > +#define ST33ZP24_BADLOCALITY 0x81 > +#define ST33ZP24_TISREGISTER_UKNOWN 0x82 > +#define ST33ZP24_LOCALITY_NOT_ACTIVATED 0x83 > +#define ST33ZP24_HASH_END_BEFORE_HASH_START 0x84 > +#define ST33ZP24_BAD_COMMAND_ORDER 0x85 > +#define ST33ZP24_INCORECT_RECEIVED_LENGTH 0x86 > +#define ST33ZP24_TPM_FIFO_OVERFLOW 0x89 > +#define ST33ZP24_UNEXPECTED_READ_FIFO 0x8A > +#define ST33ZP24_UNEXPECTED_WRITE_FIFO 0x8B > +#define ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END 0x90 > +#define ST33ZP24_DUMMY_BYTES 0x00 > + > +struct st33zp24_spi_phy { > + struct spi_device *spi_device; > + struct spi_transfer spi_xfer; > + int io_lpcpd; > + int latency; > +}; > + > +static int st33zp24_status_to_errno(u8 code) > +{ > + switch (code) { > + case ST33ZP24_OK: > + return 0; > + case ST33ZP24_UNDEFINED_ERR: > + case ST33ZP24_BADLOCALITY: > + case ST33ZP24_TISREGISTER_UKNOWN: > + case ST33ZP24_LOCALITY_NOT_ACTIVATED: > + case ST33ZP24_HASH_END_BEFORE_HASH_START: > + case ST33ZP24_BAD_COMMAND_ORDER: > + case ST33ZP24_UNEXPECTED_READ_FIFO: > + case ST33ZP24_UNEXPECTED_WRITE_FIFO: > + case ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END: > + return -EPROTO; > + case ST33ZP24_INCORECT_RECEIVED_LENGTH: > + case ST33ZP24_TPM_FIFO_OVERFLOW: > + return -EMSGSIZE; > + case ST33ZP24_DUMMY_BYTES: > + default: > + return -ENOSYS; > + } > +} > + > +/* > + * st33zp24_spi_send > + * Send byte to the TIS register according to the ST33ZP24 SPI protocol. > + * @param: tpm, the chip description no such parameter :) > + * @param: tpm_register, the tpm tis register where the data should be > written + * @param: tpm_data, the tpm_data to write inside the > tpm_register + * @param: tpm_size, The length of the data > + * @return: should be zero if success else a negative error code. > + */ > +static int st33zp24_spi_send(void *phy_id, u8 tpm_register, u8 *tpm_data, > + int tpm_size) > +{ > + u8 data = 0; > + int total_length = 0, nbr_dummy_bytes = 0, ret = 0; > + struct st33zp24_spi_phy *phy = phy_id; > + struct spi_device *dev = phy->spi_device; > + u8 *tx_buf = (u8 *)phy->spi_xfer.tx_buf; > + u8 *rx_buf = phy->spi_xfer.rx_buf; > + > + /* Pre-Header */ > + data = TPM_WRITE_DIRECTION | LOCALITY0; > + memcpy(tx_buf + total_length, &data, sizeof(data)); > + total_length++; > + data = tpm_register; > + memcpy(tx_buf + total_length, &data, sizeof(data)); > + total_length++; > + > + if (tpm_size > 0 && tpm_register == TPM_DATA_FIFO) { > + tx_buf[total_length++] = tpm_size >> 8; > + tx_buf[total_length++] = tpm_size; > + } > + > + memcpy(&tx_buf[total_length], tpm_data, tpm_size); > + total_length += tpm_size; > + > + nbr_dummy_bytes = phy->latency; > + memset(&tx_buf[total_length], TPM_DUMMY_BYTE, nbr_dummy_bytes); > + > + phy->spi_xfer.len = total_length + nbr_dummy_bytes; > + > + ret = spi_sync_transfer(dev, &phy->spi_xfer, 1); > + > + if (ret == 0) > + ret = rx_buf[total_length + nbr_dummy_bytes - 1]; > + > + return st33zp24_status_to_errno(ret); > +} /* st33zp24_spi_send() */ > + > +/* > + * read8_recv > + * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. > + * @param: tpm, the chip description no such parameter :) > + * @param: tpm_register, the tpm tis register where the data should be > read + * @param: tpm_data, the TPM response > + * @param: tpm_size, tpm TPM response size to read. > + * @return: should be zero if success else a negative error code. > + */ > +static int read8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int > tpm_size) +{ > + u8 data = 0; > + int total_length = 0, nbr_dummy_bytes, ret; > + struct st33zp24_spi_phy *phy = phy_id; > + struct spi_device *dev = phy->spi_device; > + u8 *tx_buf = (u8 *)phy->spi_xfer.tx_buf; > + u8 *rx_buf = phy->spi_xfer.rx_buf; > + > + /* Pre-Header */ > + data = LOCALITY0; > + memcpy(tx_buf + total_length, &data, sizeof(data)); > + total_length++; > + data = tpm_register; > + memcpy(tx_buf + total_length, &data, sizeof(data)); > + total_length++; > + > + nbr_dummy_bytes = phy->latency; > + memset(&tx_buf[total_length], TPM_DUMMY_BYTE, > + nbr_dummy_bytes + tpm_size); > + > + phy->spi_xfer.len = total_length + nbr_dummy_bytes + tpm_size; > + > + /* header + status byte + size of the data + status byte */ > + ret = spi_sync_transfer(dev, &phy->spi_xfer, 1); > + if (tpm_size > 0 && ret == 0) { > + ret = rx_buf[total_length + nbr_dummy_bytes - 1]; > + > + memcpy(tpm_data, rx_buf + total_length + nbr_dummy_bytes, > + tpm_size); > + } > + > + return ret; > +} /* read8_reg() */ > + > +/* > + * st33zp24_spi_recv > + * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. > + * @param: tpm, the chip description no such parameter :) > + * @param: tpm_register, the tpm tis register where the data should be > read + * @param: tpm_data, the TPM response > + * @param: tpm_size, tpm TPM response size to read. > + * @return: number of byte written successfully: should be one if success. s ^^^^^^^ written on recv? > + */ > +static int st33zp24_spi_recv(void *phy_id, u8 tpm_register, u8 *tpm_data, > + int tpm_size) > +{ > + int ret; > + > + ret = read8_reg(phy_id, tpm_register, tpm_data, tpm_size); > + if (!ret) > + return tpm_size; > + return ret; > +} /* st33zp24_spi_recv() */ > + > +static int evaluate_latency(void *phy_id) > +{ > + struct st33zp24_spi_phy *phy = phy_id; > + int latency = 1, status = 0; > + u8 data = 0; > + > + while (!status && latency < MAX_SPI_LATENCY) { > + phy->latency = latency; > + status = read8_reg(phy_id, TPM_INTF_CAPABILITY, &data, 1); > + latency++; > + } > + return latency - 1; why start at 1 and then deduce -1 at the end? > +} /* evaluate_latency() */ > + > +static const struct st33zp24_phy_ops spi_phy_ops = { > + .send = st33zp24_spi_send, > + .recv = st33zp24_spi_recv, > +}; > + > +#ifdef CONFIG_OF > +static int tpm_stm_spi_of_request_resources(struct st33zp24_spi_phy *phy) > +{ > + struct device_node *pp; > + struct spi_device *dev = phy->spi_device; > + int gpio; > + int ret; > + > + pp = dev->dev.of_node; > + if (!pp) { > + dev_err(&dev->dev, "No platform data\n"); > + return -ENODEV; > + } > + > + /* Get GPIO from device tree */ > + gpio = of_get_named_gpio(pp, "lpcpd-gpios", 0); > + if (gpio < 0) { > + dev_err(&dev->dev, > + "Failed to retrieve lpcpd-gpios from dts.\n"); > + phy->io_lpcpd = -1; > + /* > + * lpcpd pin is not specified. This is not an issue as > + * power management can be also managed by TPM specific > + * commands. So leave with a success status code. > + */ > + return 0; > + } > + /* GPIO request and configuration */ > + ret = devm_gpio_request_one(&dev->dev, gpio, > + GPIOF_OUT_INIT_HIGH, "TPM IO LPCPD"); > + if (ret) { > + dev_err(&dev->dev, "Failed to request lpcpd pin\n"); > + return -ENODEV; > + } > + phy->io_lpcpd = gpio; > + > + return 0; > +} > +#else > +static int tpm_stm_spi_of_request_resources(struct st33zp24_spi_phy *phy) > +{ > + return -ENODEV; > +} > +#endif > + > +static int tpm_stm_spi_request_resources(struct spi_device *dev, > + struct st33zp24_spi_phy *phy) > +{ > + struct st33zp24_platform_data *pdata; > + int ret; > + > + pdata = dev->dev.platform_data; > + if (!pdata) { > + dev_err(&dev->dev, "No platform data\n"); > + return -ENODEV; > + } > + > + /* store for late use */ > + phy->io_lpcpd = pdata->io_lpcpd; > + > + if (gpio_is_valid(pdata->io_lpcpd)) { > + ret = devm_gpio_request_one(&dev->dev, > + pdata->io_lpcpd, GPIOF_OUT_INIT_HIGH, > + "TPM IO_LPCPD"); > + if (ret) { > + dev_err(&dev->dev, "%s : reset gpio_request failed\n", > + __FILE__); > + return ret; > + } > + } > + > + return 0; > +} > + > +/* > + * tpm_st33_spi_probe initialize the TPM device > + * @param: client, the spi_device drescription (TPM SPI description). > + * @param: id, the spi_device_id struct. the params don't match the function below so again no such parameters :) > + * @return: 0 in case of success. > + * -1 in other case. is this true? I guess not. > + */ > +static int > +tpm_st33_spi_probe(struct spi_device *dev) > +{ > + int ret; > + struct st33zp24_platform_data *pdata; > + struct st33zp24_spi_phy *phy; > + > + /* Check SPI platform functionnalities */ > + if (!dev) { > + pr_info("%s: dev is NULL. Device is not accessible.\n", > + __func__); > + return -ENODEV; > + } > + > + phy = devm_kzalloc(&dev->dev, sizeof(struct st33zp24_spi_phy), > + GFP_KERNEL); > + if (!phy) > + return -ENOMEM; > + > + phy->spi_device = dev; > + pdata = dev->dev.platform_data; > + if (!pdata && dev->dev.of_node) { > + ret = tpm_stm_spi_of_request_resources(phy); > + if (ret) > + return ret; > + } else if (pdata) { > + ret = tpm_stm_spi_request_resources(dev, phy); > + if (ret) > + return ret; > + } > + > + phy->spi_xfer.tx_buf = devm_kmalloc(&dev->dev, (TPM_BUFSIZE + > + (TPM_BUFSIZE / 2) + TPM_DIGEST_SIZE) * I don't get this calculation, why is this bugger so big? > + sizeof(u8), GFP_KERNEL); sizeof(u8) can be removed. > + if (!phy->spi_xfer.tx_buf) > + return -ENOMEM; > + > + phy->spi_xfer.rx_buf = devm_kmalloc(&dev->dev, (TPM_BUFSIZE + > + (TPM_BUFSIZE / 2) + TPM_DIGEST_SIZE) * I don't get this calculation. > + sizeof(u8), GFP_KERNEL); sizeof(u8) can be removed. > + if (!phy->spi_xfer.rx_buf) > + return -ENOMEM; > + > + phy->latency = evaluate_latency(phy); > + if (phy->latency <= 0) > + return -ENODEV; > + > + return st33zp24_probe(phy, &spi_phy_ops, &dev->dev, dev->irq, > + phy->io_lpcpd); > +} > + > +/* > + * tpm_st33_spi_remove remove the TPM device > + * @param: client, the spi_device drescription (TPM SPI description). > + * @return: 0 in case of success. > + */ > +static int tpm_st33_spi_remove(struct spi_device *dev) > +{ > + struct tpm_chip *chip = spi_get_drvdata(dev); > + > + return st33zp24_remove(chip); > +} > + > +#ifdef CONFIG_OF > +static const struct of_device_id of_st33zp24_spi_match[] = { > + { .compatible = "st,st33zp24-spi", }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, of_st33zp24_spi_match); > +#endif > + > +static SIMPLE_DEV_PM_OPS(st33zp24_spi_ops, st33zp24_pm_suspend, > + st33zp24_pm_resume); > + > +static struct spi_driver tpm_st33_spi_driver = { > + .driver = { > + .owner = THIS_MODULE, > + .name = TPM_ST33_SPI, > + .pm = &st33zp24_spi_ops, > + .of_match_table = of_match_ptr(of_st33zp24_spi_match), > + }, > + .probe = tpm_st33_spi_probe, > + .remove = tpm_st33_spi_remove, > +}; > + > +module_spi_driver(tpm_st33_spi_driver); > + > +MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)"); > +MODULE_DESCRIPTION("STM TPM 1.2 SPI ST33 Driver"); > +MODULE_VERSION("1.3.0"); > +MODULE_LICENSE("GPL"); ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. 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diff --git a/drivers/char/tpm/st33zp24/Kconfig b/drivers/char/tpm/st33zp24/Kconfig index 51dcef5..09cb7278 100644 --- a/drivers/char/tpm/st33zp24/Kconfig +++ b/drivers/char/tpm/st33zp24/Kconfig @@ -18,3 +18,13 @@ config TCG_TIS_ST33ZP24_I2C ST33ZP24 with i2c interface. To compile this driver as a module, choose M here; the module will be called tpm_st33zp24_i2c. + +config TCG_TIS_ST33ZP24_SPI + tristate "TPM 1.2 ST33ZP24 SPI support" + depends on TCG_TIS_ST33ZP24 + depends on SPI + ---help--- + This module adds support for the STMicroelectronics TPM security chip + ST33ZP24 with spi interface. + To compile this driver as a module, choose M here; the module will be + called tpm_st33zp24_spi. diff --git a/drivers/char/tpm/st33zp24/Makefile b/drivers/char/tpm/st33zp24/Makefile index 414497f..74a722e 100644 --- a/drivers/char/tpm/st33zp24/Makefile +++ b/drivers/char/tpm/st33zp24/Makefile @@ -7,3 +7,6 @@ obj-$(CONFIG_TCG_TIS_ST33ZP24) += tpm_st33zp24.o tpm_st33zp24_i2c-objs = i2c.o obj-$(CONFIG_TCG_TIS_ST33ZP24_I2C) += tpm_st33zp24_i2c.o + +tpm_st33zp24_spi-objs = spi.o +obj-$(CONFIG_TCG_TIS_ST33ZP24_SPI) += tpm_st33zp24_spi.o diff --git a/drivers/char/tpm/st33zp24/spi.c b/drivers/char/tpm/st33zp24/spi.c new file mode 100644 index 0000000..d481478 --- /dev/null +++ b/drivers/char/tpm/st33zp24/spi.c @@ -0,0 +1,386 @@ +/* + * STMicroelectronics TPM SPI 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/spi/spi.h> +#include <linux/gpio.h> +#include <linux/of_irq.h> +#include <linux/of_gpio.h> +#include <linux/tpm.h> +#include <linux/platform_data/st33zp24.h> + +#include "st33zp24.h" + +#define TPM_DATA_FIFO 0x24 +#define TPM_INTF_CAPABILITY 0x14 + +#define TPM_DUMMY_BYTE 0x00 +#define TPM_WRITE_DIRECTION 0x80 +#define TPM_BUFSIZE 2048 + +#define MAX_SPI_LATENCY 15 +#define LOCALITY0 0 + +#define ST33ZP24_OK 0x5A +#define ST33ZP24_UNDEFINED_ERR 0x80 +#define ST33ZP24_BADLOCALITY 0x81 +#define ST33ZP24_TISREGISTER_UKNOWN 0x82 +#define ST33ZP24_LOCALITY_NOT_ACTIVATED 0x83 +#define ST33ZP24_HASH_END_BEFORE_HASH_START 0x84 +#define ST33ZP24_BAD_COMMAND_ORDER 0x85 +#define ST33ZP24_INCORECT_RECEIVED_LENGTH 0x86 +#define ST33ZP24_TPM_FIFO_OVERFLOW 0x89 +#define ST33ZP24_UNEXPECTED_READ_FIFO 0x8A +#define ST33ZP24_UNEXPECTED_WRITE_FIFO 0x8B +#define ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END 0x90 +#define ST33ZP24_DUMMY_BYTES 0x00 + +struct st33zp24_spi_phy { + struct spi_device *spi_device; + struct spi_transfer spi_xfer; + int io_lpcpd; + int latency; +}; + +static int st33zp24_status_to_errno(u8 code) +{ + switch (code) { + case ST33ZP24_OK: + return 0; + case ST33ZP24_UNDEFINED_ERR: + case ST33ZP24_BADLOCALITY: + case ST33ZP24_TISREGISTER_UKNOWN: + case ST33ZP24_LOCALITY_NOT_ACTIVATED: + case ST33ZP24_HASH_END_BEFORE_HASH_START: + case ST33ZP24_BAD_COMMAND_ORDER: + case ST33ZP24_UNEXPECTED_READ_FIFO: + case ST33ZP24_UNEXPECTED_WRITE_FIFO: + case ST33ZP24_CMDRDY_SET_WHEN_PROCESSING_HASH_END: + return -EPROTO; + case ST33ZP24_INCORECT_RECEIVED_LENGTH: + case ST33ZP24_TPM_FIFO_OVERFLOW: + return -EMSGSIZE; + case ST33ZP24_DUMMY_BYTES: + default: + return -ENOSYS; + } +} + +/* + * st33zp24_spi_send + * Send byte to the TIS register according to the ST33ZP24 SPI protocol. + * @param: tpm, the chip description + * @param: tpm_register, the tpm tis register where the data should be written + * @param: tpm_data, the tpm_data to write inside the tpm_register + * @param: tpm_size, The length of the data + * @return: should be zero if success else a negative error code. + */ +static int st33zp24_spi_send(void *phy_id, u8 tpm_register, u8 *tpm_data, + int tpm_size) +{ + u8 data = 0; + int total_length = 0, nbr_dummy_bytes = 0, ret = 0; + struct st33zp24_spi_phy *phy = phy_id; + struct spi_device *dev = phy->spi_device; + u8 *tx_buf = (u8 *)phy->spi_xfer.tx_buf; + u8 *rx_buf = phy->spi_xfer.rx_buf; + + /* Pre-Header */ + data = TPM_WRITE_DIRECTION | LOCALITY0; + memcpy(tx_buf + total_length, &data, sizeof(data)); + total_length++; + data = tpm_register; + memcpy(tx_buf + total_length, &data, sizeof(data)); + total_length++; + + if (tpm_size > 0 && tpm_register == TPM_DATA_FIFO) { + tx_buf[total_length++] = tpm_size >> 8; + tx_buf[total_length++] = tpm_size; + } + + memcpy(&tx_buf[total_length], tpm_data, tpm_size); + total_length += tpm_size; + + nbr_dummy_bytes = phy->latency; + memset(&tx_buf[total_length], TPM_DUMMY_BYTE, nbr_dummy_bytes); + + phy->spi_xfer.len = total_length + nbr_dummy_bytes; + + ret = spi_sync_transfer(dev, &phy->spi_xfer, 1); + + if (ret == 0) + ret = rx_buf[total_length + nbr_dummy_bytes - 1]; + + return st33zp24_status_to_errno(ret); +} /* st33zp24_spi_send() */ + +/* + * read8_recv + * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. + * @param: tpm, the chip description + * @param: tpm_register, the tpm tis register where the data should be read + * @param: tpm_data, the TPM response + * @param: tpm_size, tpm TPM response size to read. + * @return: should be zero if success else a negative error code. + */ +static int read8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size) +{ + u8 data = 0; + int total_length = 0, nbr_dummy_bytes, ret; + struct st33zp24_spi_phy *phy = phy_id; + struct spi_device *dev = phy->spi_device; + u8 *tx_buf = (u8 *)phy->spi_xfer.tx_buf; + u8 *rx_buf = phy->spi_xfer.rx_buf; + + /* Pre-Header */ + data = LOCALITY0; + memcpy(tx_buf + total_length, &data, sizeof(data)); + total_length++; + data = tpm_register; + memcpy(tx_buf + total_length, &data, sizeof(data)); + total_length++; + + nbr_dummy_bytes = phy->latency; + memset(&tx_buf[total_length], TPM_DUMMY_BYTE, + nbr_dummy_bytes + tpm_size); + + phy->spi_xfer.len = total_length + nbr_dummy_bytes + tpm_size; + + /* header + status byte + size of the data + status byte */ + ret = spi_sync_transfer(dev, &phy->spi_xfer, 1); + if (tpm_size > 0 && ret == 0) { + ret = rx_buf[total_length + nbr_dummy_bytes - 1]; + + memcpy(tpm_data, rx_buf + total_length + nbr_dummy_bytes, + tpm_size); + } + + return ret; +} /* read8_reg() */ + +/* + * st33zp24_spi_recv + * Recv byte from the TIS register according to the ST33ZP24 SPI protocol. + * @param: tpm, the chip description + * @param: tpm_register, the tpm tis register where the data should be read + * @param: tpm_data, the TPM response + * @param: tpm_size, tpm TPM response size to read. + * @return: number of byte written successfully: should be one if success. + */ +static int st33zp24_spi_recv(void *phy_id, u8 tpm_register, u8 *tpm_data, + int tpm_size) +{ + int ret; + + ret = read8_reg(phy_id, tpm_register, tpm_data, tpm_size); + if (!ret) + return tpm_size; + return ret; +} /* st33zp24_spi_recv() */ + +static int evaluate_latency(void *phy_id) +{ + struct st33zp24_spi_phy *phy = phy_id; + int latency = 1, status = 0; + u8 data = 0; + + while (!status && latency < MAX_SPI_LATENCY) { + phy->latency = latency; + status = read8_reg(phy_id, TPM_INTF_CAPABILITY, &data, 1); + latency++; + } + return latency - 1; +} /* evaluate_latency() */ + +static const struct st33zp24_phy_ops spi_phy_ops = { + .send = st33zp24_spi_send, + .recv = st33zp24_spi_recv, +}; + +#ifdef CONFIG_OF +static int tpm_stm_spi_of_request_resources(struct st33zp24_spi_phy *phy) +{ + struct device_node *pp; + struct spi_device *dev = phy->spi_device; + int gpio; + int ret; + + pp = dev->dev.of_node; + if (!pp) { + dev_err(&dev->dev, "No platform data\n"); + return -ENODEV; + } + + /* Get GPIO from device tree */ + gpio = of_get_named_gpio(pp, "lpcpd-gpios", 0); + if (gpio < 0) { + dev_err(&dev->dev, + "Failed to retrieve lpcpd-gpios from dts.\n"); + phy->io_lpcpd = -1; + /* + * lpcpd pin is not specified. This is not an issue as + * power management can be also managed by TPM specific + * commands. So leave with a success status code. + */ + return 0; + } + /* GPIO request and configuration */ + ret = devm_gpio_request_one(&dev->dev, gpio, + GPIOF_OUT_INIT_HIGH, "TPM IO LPCPD"); + if (ret) { + dev_err(&dev->dev, "Failed to request lpcpd pin\n"); + return -ENODEV; + } + phy->io_lpcpd = gpio; + + return 0; +} +#else +static int tpm_stm_spi_of_request_resources(struct st33zp24_spi_phy *phy) +{ + return -ENODEV; +} +#endif + +static int tpm_stm_spi_request_resources(struct spi_device *dev, + struct st33zp24_spi_phy *phy) +{ + struct st33zp24_platform_data *pdata; + int ret; + + pdata = dev->dev.platform_data; + if (!pdata) { + dev_err(&dev->dev, "No platform data\n"); + return -ENODEV; + } + + /* store for late use */ + phy->io_lpcpd = pdata->io_lpcpd; + + if (gpio_is_valid(pdata->io_lpcpd)) { + ret = devm_gpio_request_one(&dev->dev, + pdata->io_lpcpd, GPIOF_OUT_INIT_HIGH, + "TPM IO_LPCPD"); + if (ret) { + dev_err(&dev->dev, "%s : reset gpio_request failed\n", + __FILE__); + return ret; + } + } + + return 0; +} + +/* + * tpm_st33_spi_probe initialize the TPM device + * @param: client, the spi_device drescription (TPM SPI description). + * @param: id, the spi_device_id struct. + * @return: 0 in case of success. + * -1 in other case. + */ +static int +tpm_st33_spi_probe(struct spi_device *dev) +{ + int ret; + struct st33zp24_platform_data *pdata; + struct st33zp24_spi_phy *phy; + + /* Check SPI platform functionnalities */ + if (!dev) { + pr_info("%s: dev is NULL. Device is not accessible.\n", + __func__); + return -ENODEV; + } + + phy = devm_kzalloc(&dev->dev, sizeof(struct st33zp24_spi_phy), + GFP_KERNEL); + if (!phy) + return -ENOMEM; + + phy->spi_device = dev; + pdata = dev->dev.platform_data; + if (!pdata && dev->dev.of_node) { + ret = tpm_stm_spi_of_request_resources(phy); + if (ret) + return ret; + } else if (pdata) { + ret = tpm_stm_spi_request_resources(dev, phy); + if (ret) + return ret; + } + + phy->spi_xfer.tx_buf = devm_kmalloc(&dev->dev, (TPM_BUFSIZE + + (TPM_BUFSIZE / 2) + TPM_DIGEST_SIZE) * + sizeof(u8), GFP_KERNEL); + if (!phy->spi_xfer.tx_buf) + return -ENOMEM; + + phy->spi_xfer.rx_buf = devm_kmalloc(&dev->dev, (TPM_BUFSIZE + + (TPM_BUFSIZE / 2) + TPM_DIGEST_SIZE) * + sizeof(u8), GFP_KERNEL); + if (!phy->spi_xfer.rx_buf) + return -ENOMEM; + + phy->latency = evaluate_latency(phy); + if (phy->latency <= 0) + return -ENODEV; + + return st33zp24_probe(phy, &spi_phy_ops, &dev->dev, dev->irq, + phy->io_lpcpd); +} + +/* + * tpm_st33_spi_remove remove the TPM device + * @param: client, the spi_device drescription (TPM SPI description). + * @return: 0 in case of success. + */ +static int tpm_st33_spi_remove(struct spi_device *dev) +{ + struct tpm_chip *chip = spi_get_drvdata(dev); + + return st33zp24_remove(chip); +} + +#ifdef CONFIG_OF +static const struct of_device_id of_st33zp24_spi_match[] = { + { .compatible = "st,st33zp24-spi", }, + {} +}; +MODULE_DEVICE_TABLE(of, of_st33zp24_spi_match); +#endif + +static SIMPLE_DEV_PM_OPS(st33zp24_spi_ops, st33zp24_pm_suspend, + st33zp24_pm_resume); + +static struct spi_driver tpm_st33_spi_driver = { + .driver = { + .owner = THIS_MODULE, + .name = TPM_ST33_SPI, + .pm = &st33zp24_spi_ops, + .of_match_table = of_match_ptr(of_st33zp24_spi_match), + }, + .probe = tpm_st33_spi_probe, + .remove = tpm_st33_spi_remove, +}; + +module_spi_driver(tpm_st33_spi_driver); + +MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)"); +MODULE_DESCRIPTION("STM TPM 1.2 SPI ST33 Driver"); +MODULE_VERSION("1.3.0"); +MODULE_LICENSE("GPL");