text: /*
   * This file is part of the coreboot project.
   *
   * Copyright (C) 2011 The Chromium OS Authors. All rights reserved.
   *
   * 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; version 2 of the License.
   *
   * 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.
   */
  
  /*
   * The code in this file has been heavily based on the article "Writing a TPM
   * Device Driver" published on http://ptgmedia.pearsoncmg.com and the
   * submission by Stefan Berger on Qemu-devel mailing list.
   *
   * One principal difference is that in the simplest config the other than 0
   * TPM localities do not get mapped by some devices (for instance, by
   * Infineon slb9635), so this driver provides access to locality 0 only.
   */
  
  #include <stdlib.h>
  #include <string.h>
  #include <delay.h>
  #include <arch/io.h>
  #include <arch/acpi.h>
  #include <arch/acpigen.h>
  #include <arch/acpi_device.h>
  #include <device/device.h>
  #include <console/console.h>
  #include <security/tpm/tis.h>
  #include <arch/early_variables.h>
  #include <device/pnp.h>
  #include "chip.h"
  
  #define PREFIX "lpc_tpm: "
  /* TCG Physical Presence Interface */
  #define TPM_PPI_UUID	"3dddfaa6-361b-4eb4-a424-8d10089d1653"
  /* TCG Memory Clear Interface */
  #define TPM_MCI_UUID	"376054ed-cc13-4675-901c-4756d7f2d45d"
  /* coreboot wrapper for TPM driver (start) */
  #define	TPM_DEBUG(fmt, args...)		\
  	if (IS_ENABLED(CONFIG_DEBUG_TPM)) {		\
  		printk(BIOS_DEBUG, PREFIX);		\
  		printk(BIOS_DEBUG, fmt , ##args);	\
  	}
  #define TPM_DEBUG_IO_READ(reg_, val_) \
  	TPM_DEBUG("Read reg 0x%x returns 0x%x\n", (reg_), (val_))
  #define TPM_DEBUG_IO_WRITE(reg_, val_) \
  	TPM_DEBUG("Write reg 0x%x with 0x%x\n", (reg_), (val_))
  #define printf(x...) printk(BIOS_ERR, x)
  
  /* coreboot wrapper for TPM driver (end) */
  
  /* the macro accepts the locality value, but only locality 0 is operational */
  #define TIS_REG(LOCALITY, REG) \
  	(void *)(CONFIG_TPM_TIS_BASE_ADDRESS + (LOCALITY << 12) + REG)
  
  /* hardware registers' offsets */
  #define TIS_REG_ACCESS                 0x0
  #define TIS_REG_INT_ENABLE             0x8
  #define TIS_REG_INT_VECTOR             0xc
  #define TIS_REG_INT_STATUS             0x10
  #define TIS_REG_INTF_CAPABILITY        0x14
  #define TIS_REG_STS                    0x18
  #define TIS_REG_BURST_COUNT            0x19
  #define TIS_REG_DATA_FIFO              0x24
  #define TIS_REG_DID_VID                0xf00
  #define TIS_REG_RID                    0xf04
  
  /* Some registers' bit field definitions */
  #define TIS_STS_VALID                  (1 << 7) /* 0x80 */
  #define TIS_STS_COMMAND_READY          (1 << 6) /* 0x40 */
  #define TIS_STS_TPM_GO                 (1 << 5) /* 0x20 */
  #define TIS_STS_DATA_AVAILABLE         (1 << 4) /* 0x10 */
  #define TIS_STS_EXPECT                 (1 << 3) /* 0x08 */
  #define TIS_STS_RESPONSE_RETRY         (1 << 1) /* 0x02 */
  
  #define TIS_ACCESS_TPM_REG_VALID_STS   (1 << 7) /* 0x80 */
  #define TIS_ACCESS_ACTIVE_LOCALITY     (1 << 5) /* 0x20 */
  #define TIS_ACCESS_BEEN_SEIZED         (1 << 4) /* 0x10 */
  #define TIS_ACCESS_SEIZE               (1 << 3) /* 0x08 */
  #define TIS_ACCESS_PENDING_REQUEST     (1 << 2) /* 0x04 */
  #define TIS_ACCESS_REQUEST_USE         (1 << 1) /* 0x02 */
  #define TIS_ACCESS_TPM_ESTABLISHMENT   (1 << 0) /* 0x01 */
  
  /*
   * Error value returned if a tpm register does not enter the expected state
   * after continuous polling. No actual TPM register reading ever returns ~0,
   * so this value is a safe error indication to be mixed with possible status
   * register values.
   */
  #define TPM_TIMEOUT_ERR			(~0)
  
  /* Error value returned on various TPM driver errors */
  #define TPM_DRIVER_ERR		(~0)
  
   /* 1 second is plenty for anything TPM does.*/
  #define MAX_DELAY_US	(1000 * 1000)
  
  /*
   * Structures defined below allow creating descriptions of TPM vendor/device
   * ID information for run time discovery. The only device the system knows
   * about at this time is Infineon slb9635
   */
  struct device_name {
  	u16 dev_id;
  	const char * const dev_name;
  };
  
  struct vendor_name {
  	u16 vendor_id;
  	const char * vendor_name;
  	const struct device_name* dev_names;
  };
  
  static const struct device_name atmel_devices[] = {
  	{0x3204, "AT97SC3204"},
  	{0xffff}
  };
  
  static const struct device_name infineon_devices[] = {
  	{0x000b, "SLB9635 TT 1.2"},
  	{0x001a, "SLB9660 TT 1.2"},
  #if IS_ENABLED(CONFIG_TPM2)
  	{0x001b, "SLB9670 TT 2.0"},
  #else
  	{0x001b, "SLB9670 TT 1.2"},
  #endif
  	{0xffff}
  };
  
  static const struct device_name nuvoton_devices[] = {
  	{0x00fe, "NPCT420AA V2"},
  	{0xffff}
  };
  
  static const struct device_name stmicro_devices[] = {
  	{0x0000, "ST33ZP24" },
  	{0xffff}
  };
  
  static const struct vendor_name vendor_names[] = {
  	{0x1114, "Atmel", atmel_devices},
  	{0x15d1, "Infineon", infineon_devices},
  	{0x1050, "Nuvoton", nuvoton_devices},
  	{0x104a, "ST Microelectronics", stmicro_devices},
  };
  
  /*
   * Cached vendor/device ID pair to indicate that the device has been already
   * discovered
   */
  static u32 vendor_dev_id CAR_GLOBAL;
  
  static inline u8 tpm_read_status(int locality)
  {
  	u8 value = read8(TIS_REG(locality, TIS_REG_STS));
  	TPM_DEBUG_IO_READ(TIS_REG_STS, value);
  	return value;
  }
  
  static inline void tpm_write_status(u8 sts, int locality)
  {
  	TPM_DEBUG_IO_WRITE(TIS_REG_STS, sts);
  	write8(TIS_REG(locality, TIS_REG_STS), sts);
  }
  
  static inline u8 tpm_read_data(int locality)
  {
  	u8 value = read8(TIS_REG(locality, TIS_REG_DATA_FIFO));
  	TPM_DEBUG_IO_READ(TIS_REG_DATA_FIFO, value);
  	return value;
  }
  
  static inline void tpm_write_data(u8 data, int locality)
  {
  	TPM_DEBUG_IO_WRITE(TIS_REG_STS, data);
  	write8(TIS_REG(locality, TIS_REG_DATA_FIFO), data);
  }
  
  static inline u16 tpm_read_burst_count(int locality)
  {
  	u16 count;
  	count = read8(TIS_REG(locality, TIS_REG_BURST_COUNT));
  	count |= read8(TIS_REG(locality, TIS_REG_BURST_COUNT + 1)) << 8;
  	TPM_DEBUG_IO_READ(TIS_REG_BURST_COUNT, count);
  	return count;
  }
  
  static inline u8 tpm_read_access(int locality)
  {
  	u8 value = read8(TIS_REG(locality, TIS_REG_ACCESS));
  	TPM_DEBUG_IO_READ(TIS_REG_ACCESS, value);
  	return value;
  }
  
  static inline void tpm_write_access(u8 data, int locality)
  {
  	TPM_DEBUG_IO_WRITE(TIS_REG_ACCESS, data);
  	write8(TIS_REG(locality, TIS_REG_ACCESS), data);
  }
  
  static inline u32 tpm_read_did_vid(int locality)
  {
  	u32 value = read32(TIS_REG(locality, TIS_REG_DID_VID));
  	TPM_DEBUG_IO_READ(TIS_REG_DID_VID, value);
  	return value;
  }
  
  static inline void tpm_write_int_vector(int vector, int locality)
  {
  	TPM_DEBUG_IO_WRITE(TIS_REG_INT_VECTOR, vector);
  	write8(TIS_REG(locality, TIS_REG_INT_VECTOR), vector & 0xf);
  }
  
  static inline u8 tpm_read_int_vector(int locality)
  {
  	u8 value = read8(TIS_REG(locality, TIS_REG_INT_VECTOR));
  	TPM_DEBUG_IO_READ(TIS_REG_INT_VECTOR, value);
  	return value;
  }
  
  static inline void tpm_write_int_polarity(int polarity, int locality)
  {
  	/* Set polarity and leave all other bits at 0 */
  	u32 value = (polarity & 0x3) << 3;
  	TPM_DEBUG_IO_WRITE(TIS_REG_INT_ENABLE, value);
  	write32(TIS_REG(locality, TIS_REG_INT_ENABLE), value);
  }
  
  static inline u32 tpm_read_int_polarity(int locality)
  {
  	/* Get polarity and leave all other bits */
  	u32 value = read8(TIS_REG(locality, TIS_REG_INT_ENABLE));
  	value = (value >> 3) & 0x3;
  	TPM_DEBUG_IO_READ(TIS_REG_INT_ENABLE, value);
  	return value;
  }
  
  /*
   * tis_wait_sts()
   *
   * Wait for at least a second for a status to change its state to match the
   * expected state. Normally the transition happens within microseconds.
   *
   * @locality - locality
   * @mask - bitmask for the bitfield(s) to watch
   * @expected - value the field(s) are supposed to be set to
   *
   * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
   */
  static int tis_wait_sts(int locality, u8 mask, u8 expected)
  {
  	u32 time_us = MAX_DELAY_US;
  	while (time_us > 0) {
  		u8 value = tpm_read_status(locality);
  		if ((value & mask) == expected)
  			return 0;
  		udelay(1); /* 1 us */
  		time_us--;
  	}
  	return TPM_TIMEOUT_ERR;
  }
  
  static inline int tis_wait_ready(int locality)
  {
  	return tis_wait_sts(locality, TIS_STS_COMMAND_READY,
  	                    TIS_STS_COMMAND_READY);
  }
  
  static inline int tis_wait_valid(int locality)
  {
  	return tis_wait_sts(locality, TIS_STS_VALID, TIS_STS_VALID);
  }
  
  static inline int tis_wait_valid_data(int locality)
  {
  	const u8 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
  	return tis_wait_sts(locality, has_data, has_data);
  }
  
  static inline int tis_has_valid_data(int locality)
  {
  	const u8 has_data = TIS_STS_DATA_AVAILABLE | TIS_STS_VALID;
  	return (tpm_read_status(locality) & has_data) == has_data;
  }
  
  static inline int tis_expect_data(int locality)
  {
  	return !!(tpm_read_status(locality) & TIS_STS_EXPECT);
  }
  
  /*
   * tis_wait_access()
   *
   * Wait for at least a second for a access to change its state to match the
   * expected state. Normally the transition happens within microseconds.
   *
   * @locality - locality
   * @mask - bitmask for the bitfield(s) to watch
   * @expected - value the field(s) are supposed to be set to
   *
   * Returns 0 on success or TPM_TIMEOUT_ERR on timeout.
   */
  static int tis_wait_access(int locality, u8 mask, u8 expected)
  {
  	u32 time_us = MAX_DELAY_US;
  	while (time_us > 0) {
  		u8 value = tpm_read_access(locality);
  		if ((value & mask) == expected)
  			return 0;
  		udelay(1); /* 1 us */
  		time_us--;
  	}
  	return TPM_TIMEOUT_ERR;
  }
  
  static inline int tis_wait_dropped_access(int locality)
  {
  	return tis_wait_access(locality, TIS_ACCESS_ACTIVE_LOCALITY, 0);
  }
  
  static inline int tis_wait_received_access(int locality)
  {
  	return tis_wait_access(locality, TIS_ACCESS_ACTIVE_LOCALITY,
  	                       TIS_ACCESS_ACTIVE_LOCALITY);
  }
  
  static inline int tis_has_access(int locality)
  {
  	return !!(tpm_read_access(locality) & TIS_ACCESS_ACTIVE_LOCALITY);
  }
  
  static inline void tis_request_access(int locality)
  {
  	tpm_write_access(TIS_ACCESS_REQUEST_USE, locality);
  }
  
  static inline void tis_drop_access(int locality)
  {
  	tpm_write_access(TIS_ACCESS_ACTIVE_LOCALITY, locality);
  }
  
  /*
   * PC Client Specific TPM Interface Specification section 11.2.12:
   *
   *  Software must be prepared to send two writes of a "1" to command ready
   *  field: the first to indicate successful read of all the data, thus
   *  clearing the data from the ReadFIFO and freeing the TPM's resources,
   *  and the second to indicate to the TPM it is about to send a new command.
   *
   * In practice not all TPMs behave the same so it is necessary to be
   * flexible when trying to set command ready.
   *
   * Returns 0 on success if the TPM is ready for transactions.
   * Returns TPM_TIMEOUT_ERR if the command ready bit does not get set.
   */
  static int tis_command_ready(u8 locality)
  {
  	u32 status;
  
  	/* 1st attempt to set command ready */
  	tpm_write_status(TIS_STS_COMMAND_READY, locality);
  
  	/* Wait for response */
  	status = tpm_read_status(locality);
  
  	/* Check if command ready is set yet */
  	if (status & TIS_STS_COMMAND_READY)
  		return 0;
  
  	/* 2nd attempt to set command ready */
  	tpm_write_status(TIS_STS_COMMAND_READY, locality);
  
  	return tis_wait_ready(locality);
  }
  
  /*
   * Probe the TPM device and try determining its manufacturer/device name.
   *
   * Returns 0 on success (the device is found or was found during an earlier
   * invocation) or TPM_DRIVER_ERR if the device is not found.
   */
  static u32 tis_probe(void)
  {
  	const char *device_name = "unknown";
  	const char *vendor_name = device_name;
  	const struct device_name *dev;
  	u32 didvid;
  	u16 vid, did;
  	int i;
  
  	if (car_get_var(vendor_dev_id))
  		return 0;  /* Already probed. */
  
  	didvid = tpm_read_did_vid(0);
  	if (!didvid || (didvid == 0xffffffff)) {
  		printf("%s: No TPM device found\n", __FUNCTION__);
  		return TPM_DRIVER_ERR;
  	}
  
  	car_set_var(vendor_dev_id, didvid);
  
  	vid = didvid & 0xffff;
  	did = (didvid >> 16) & 0xffff;
  	for (i = 0; i < ARRAY_SIZE(vendor_names); i++) {
  		int j = 0;
  		u16 known_did;
  		if (vid == vendor_names[i].vendor_id) {
  			vendor_name = vendor_names[i].vendor_name;
  		} else {
  			continue;
  		}
  		dev = &vendor_names[i].dev_names[j];
  		while ((known_did = dev->dev_id) != 0xffff) {
  			if (known_did == did) {
  				device_name = dev->dev_name;
  				break;
  			}
  			j++;
  			dev = &vendor_names[i].dev_names[j];
  		}
  		break;
  	}
  	/* this will have to be converted into debug printout */
  	printk(BIOS_INFO, "Found TPM %s by %s\n", device_name, vendor_name);
  	return 0;
  }
  
  /*
   * tis_senddata()
   *
   * send the passed in data to the TPM device.
   *
   * @data - address of the data to send, byte by byte
   * @len - length of the data to send
   *
   * Returns 0 on success, TPM_DRIVER_ERR on error (in case the device does
   * not accept the entire command).
   */
  static u32 tis_senddata(const u8 * const data, u32 len)
  {
  	u32 offset = 0;
  	u16 burst = 0;
  	u32 max_cycles = 0;
  	u8 locality = 0;
  
  	if (tis_wait_ready(locality)) {
  		printf("%s:%d - failed to get 'command_ready' status\n",
  		       __FILE__, __LINE__);
  		return TPM_DRIVER_ERR;
  	}
  	burst = tpm_read_burst_count(locality);
  
  	while (1) {
  		unsigned count;
  
  		/* Wait till the device is ready to accept more data. */
  		while (!burst) {
  			if (max_cycles++ == MAX_DELAY_US) {
  				printf("%s:%d failed to feed %d bytes of %d\n",
  				       __FILE__, __LINE__, len - offset, len);
  				return TPM_DRIVER_ERR;
  			}
  			udelay(1);
  			burst = tpm_read_burst_count(locality);
  		}
  
  		max_cycles = 0;
  
  		/*
  		 * Calculate number of bytes the TPM is ready to accept in one
  		 * shot.
  		 *
  		 * We want to send the last byte outside of the loop (hence
  		 * the -1 below) to make sure that the 'expected' status bit
  		 * changes to zero exactly after the last byte is fed into the
  		 * FIFO.
  		 */
  		count = min(burst, len - offset - 1);
  		while (count--)
  			tpm_write_data(data[offset++], locality);
  
  		if (tis_wait_valid(locality) || !tis_expect_data(locality)) {
  			printf("%s:%d TPM command feed overflow\n",
  			       __FILE__, __LINE__);
  			return TPM_DRIVER_ERR;
  		}
  
  		burst = tpm_read_burst_count(locality);
  		if ((offset == (len - 1)) && burst)
  			/*
  			 * We need to be able to send the last byte to the
  			 * device, so burst size must be nonzero before we
  			 * break out.
  			 */
  			break;
  	}
  
  	/* Send the last byte. */
  	tpm_write_data(data[offset++], locality);
  
  	/*
  	 * Verify that TPM does not expect any more data as part of this
  	 * command.
  	 */
  	if (tis_wait_valid(locality) || tis_expect_data(locality)) {
  		printf("%s:%d unexpected TPM status 0x%x\n",
  		       __FILE__, __LINE__, tpm_read_status(locality));
  		return TPM_DRIVER_ERR;
  	}
  
  	/* OK, sitting pretty, let's start the command execution. */
  	tpm_write_status(TIS_STS_TPM_GO, locality);
  
  	return 0;
  }
  
  /*
   * tis_readresponse()
   *
   * read the TPM device response after a command was issued.
   *
   * @buffer - address where to read the response, byte by byte.
   * @len - pointer to the size of buffer
   *
   * On success stores the number of received bytes to len and returns 0. On
   * errors (misformatted TPM data or synchronization problems) returns
   * TPM_DRIVER_ERR.
   */
  static u32 tis_readresponse(u8 *buffer, size_t *len)
  {
  	u16 burst_count;
  	u32 offset = 0;
  	u8 locality = 0;
  	u32 expected_count = *len;
  	int max_cycles = 0;
  
  	/* Wait for the TPM to process the command */
  	if (tis_wait_valid_data(locality)) {
  		printf("%s:%d failed processing command\n", __FILE__, __LINE__);
  		return TPM_DRIVER_ERR;
  	}
  
  	do {
  		while ((burst_count = tpm_read_burst_count(locality)) == 0) {
  			if (max_cycles++ == MAX_DELAY_US) {
  				printf("%s:%d TPM stuck on read\n",
  				       __FILE__, __LINE__);
  				return TPM_DRIVER_ERR;
  			}
  			udelay(1);
  		}
  
  		max_cycles = 0;
  
  		while (burst_count-- && (offset < expected_count)) {
  			buffer[offset++] = tpm_read_data(locality);
  			if (offset == 6) {
  				/*
  				 * We got the first six bytes of the reply,
  				 * let's figure out how many bytes to expect
  				 * total - it is stored as a 4 byte number in
  				 * network order, starting with offset 2 into
  				 * the body of the reply.
  				 */
  				u32 real_length;
  				memcpy(&real_length,
  				       buffer + 2,
  				       sizeof(real_length));
  				expected_count = be32_to_cpu(real_length);
  
  				if ((expected_count < offset) ||
  				    (expected_count > *len)) {
  					printf("%s:%d bad response size %d\n",
  					       __FILE__, __LINE__,
  					       expected_count);
  					return TPM_DRIVER_ERR;
  				}
  			}
  		}
  
  		/* Wait for the next portion */
  		if (tis_wait_valid(locality)) {
  			printf("%s:%d failed to read response\n",
  			       __FILE__, __LINE__);
  			return TPM_DRIVER_ERR;
  		}
  
  		if (offset == expected_count)
  			break;	/* We got all we need */
  
  		/*
  		 * Certain TPMs seem to need some delay between tis_wait_valid()
  		 * and tis_has_valid_data(), or some race-condition-related
  		 * issue will occur.
  		 */
  		if (IS_ENABLED(CONFIG_TPM_RDRESP_NEED_DELAY))
  			udelay(10);
  
  	} while (tis_has_valid_data(locality));
  
  	/* * Make sure we indeed read all there was. */
  	if (tis_has_valid_data(locality)) {
  		printf("%s:%d wrong receive status: %x %d bytes left\n",
  		       __FILE__, __LINE__, tpm_read_status(locality),
  	               tpm_read_burst_count(locality));
  		return TPM_DRIVER_ERR;
  	}
  
  	/* Tell the TPM that we are done. */
  	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
  		return TPM_DRIVER_ERR;
  
  	*len = offset;
  	return 0;
  }
  
  /*
   * tis_init()
   *
   * Initialize the TPM device. Returns 0 on success or TPM_DRIVER_ERR on
   * failure (in case device probing did not succeed).
   */
  int tis_init(void)
  {
  	if (tis_probe())
  		return TPM_DRIVER_ERR;
  	return 0;
  }
  
  /*
   * tis_open()
   *
   * Requests access to locality 0 for the caller. After all commands have been
   * completed the caller is supposed to call tis_close().
   *
   * Returns 0 on success, TPM_DRIVER_ERR on failure.
   */
  int tis_open(void)
  {
  	u8 locality = 0; /* we use locality zero for everything */
  
  	if (tis_close())
  		return TPM_DRIVER_ERR;
  
  	/* now request access to locality */
  	tis_request_access(locality);
  
  	/* did we get a lock? */
  	if (tis_wait_received_access(locality)) {
  		printf("%s:%d - failed to lock locality %d\n",
  		       __FILE__, __LINE__, locality);
  		return TPM_DRIVER_ERR;
  	}
  
  	/* Certain TPMs seem to need some delay here or they hang... */
  	udelay(10);
  
  	if (tis_command_ready(locality) == TPM_TIMEOUT_ERR)
  		return TPM_DRIVER_ERR;
  
  	return 0;
  }
  
  /*
   * tis_close()
   *
   * terminate the current session with the TPM by releasing the locked
   * locality. Returns 0 on success of TPM_DRIVER_ERR on failure (in case lock
   * removal did not succeed).
   */
  int tis_close(void)
  {
  	u8 locality = 0;
  	if (tis_has_access(locality)) {
  		tis_drop_access(locality);
  		if (tis_wait_dropped_access(locality)) {
  			printf("%s:%d - failed to release locality %d\n",
  			       __FILE__, __LINE__, locality);
  			return TPM_DRIVER_ERR;
  		}
  	}
  	return 0;
  }
  
  /*
   * tis_sendrecv()
   *
   * Send the requested data to the TPM and then try to get its response
   *
   * @sendbuf - buffer of the data to send
   * @send_size size of the data to send
   * @recvbuf - memory to save the response to
   * @recv_len - pointer to the size of the response buffer
   *
   * Returns 0 on success (and places the number of response bytes at recv_len)
   * or TPM_DRIVER_ERR on failure.
   */
  int tis_sendrecv(const uint8_t *sendbuf, size_t send_size,
  		 uint8_t *recvbuf, size_t *recv_len)
  {
  	if (tis_senddata(sendbuf, send_size)) {
  		printf("%s:%d failed sending data to TPM\n",
  		       __FILE__, __LINE__);
  		return TPM_DRIVER_ERR;
  	}
  
  	return tis_readresponse(recvbuf, recv_len);
  }
  
  #ifdef __RAMSTAGE__
  
  /*
   * tis_setup_interrupt()
   *
   * Set up the interrupt vector and polarity for locality 0 and
   * disable all interrupts so they are unused in firmware but can
   * be enabled by the OS.
   *
   * The values used here must match what is passed in the TPM ACPI
   * device if ACPI is used on the platform.
   *
   * @vector - TPM interrupt vector
   * @polarity - TPM interrupt polarity
   *
   * Returns 0 on success, TPM_DRIVER_ERR on failure.
   */
  static int tis_setup_interrupt(int vector, int polarity)
  {
  	u8 locality = 0;
  	int has_access = tis_has_access(locality);
  
  	/* Open connection and request access if not already granted */
  	if (!has_access && tis_open() < 0)
  		return TPM_DRIVER_ERR;
  
  	/* Set TPM interrupt vector */
  	tpm_write_int_vector(vector, locality);
  
  	/* Set TPM interupt polarity and disable interrupts */
  	tpm_write_int_polarity(polarity, locality);
  
  	/* Close connection if it was opened */
  	if (!has_access && tis_close() < 0)
  		return TPM_DRIVER_ERR;
  
  	return 0;
  }
  
  static void lpc_tpm_read_resources(struct device *dev)
  {
  	/* Static 5K memory region specified in Kconfig */
  	mmio_resource(dev, 0, CONFIG_TPM_TIS_BASE_ADDRESS >> 10, 0x5000 >> 10);
  }
  
  static void lpc_tpm_set_resources(struct device *dev)
  {
  	tpm_config_t *config = (tpm_config_t *)dev->chip_info;
  	struct resource *res;
  
  	for (res = dev->resource_list; res; res = res->next) {
  		if (!(res->flags & IORESOURCE_ASSIGNED))
  			continue;
  
  		if (res->flags & IORESOURCE_IRQ) {
  			/* Set interrupt vector */
  			tis_setup_interrupt((int)res->base,
  					    config->irq_polarity);
  		} else {
  			continue;
  		}
  
  		res->flags |= IORESOURCE_STORED;
  		report_resource_stored(dev, res, " <tpm>");
  	}
  }
  
  #if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
  
  static void tpm_ppi_func0_cb(void *arg)
  {
  	/* Functions 1-8. */
  	u8 buf[] = {0xff, 0x01};
  	acpigen_write_return_byte_buffer(buf, 2);
  }
  
  static void tpm_ppi_func1_cb(void *arg)
  {
  	if (IS_ENABLED(CONFIG_TPM2))
  		/* Interface version: 2.0 */
  		acpigen_write_return_string("2.0");
  	else
  		/* Interface version: 1.2 */
  		acpigen_write_return_string("1.2");
  }
  
  static void tpm_ppi_func2_cb(void *arg)
  {
  	/* Submit operations: drop on the floor and return success. */
  	acpigen_write_return_byte(0);
  }
  
  static void tpm_ppi_func3_cb(void *arg)
  {
  	/* Pending operation: none. */
  	acpigen_emit_byte(RETURN_OP);
  	acpigen_write_package(2);
  	acpigen_write_byte(0);
  	acpigen_write_byte(0);
  	acpigen_pop_len();
  }
  static void tpm_ppi_func4_cb(void *arg)
  {
  	/* Pre-OS transition method: reboot. */
  	acpigen_write_return_byte(2);
  }
  static void tpm_ppi_func5_cb(void *arg)
  {
  	/* Operation response: no operation executed. */
  	acpigen_emit_byte(RETURN_OP);
  	acpigen_write_package(3);
  	acpigen_write_byte(0);
  	acpigen_write_byte(0);
  	acpigen_write_byte(0);
  	acpigen_pop_len();
  }
  static void tpm_ppi_func6_cb(void *arg)
  {
  	/*
  	 * Set preferred user language: deprecated and must return 3 aka
  	 * "not implemented".
  	 */
  	acpigen_write_return_byte(3);
  }
  static void tpm_ppi_func7_cb(void *arg)
  {
  	/* Submit operations: deny. */
  	acpigen_write_return_byte(3);
  }
  static void tpm_ppi_func8_cb(void *arg)
  {
  	/* All actions are forbidden. */
  	acpigen_write_return_byte(1);
  }
  static void (*tpm_ppi_callbacks[])(void *) = {
  	tpm_ppi_func0_cb,
  	tpm_ppi_func1_cb,
  	tpm_ppi_func2_cb,
  	tpm_ppi_func3_cb,
  	tpm_ppi_func4_cb,
  	tpm_ppi_func5_cb,
  	tpm_ppi_func6_cb,
  	tpm_ppi_func7_cb,
  	tpm_ppi_func8_cb,
  };
  
  static void tpm_mci_func0_cb(void *arg)
  {
  	/* Function 1. */
  	acpigen_write_return_singleton_buffer(0x3);
  }
  static void tpm_mci_func1_cb(void *arg)
  {
  	/* Just return success. */
  	acpigen_write_return_byte(0);
  }
  
  static void (*tpm_mci_callbacks[])(void *) = {
  	tpm_mci_func0_cb,
  	tpm_mci_func1_cb,
  };
  
  static void lpc_tpm_fill_ssdt(struct device *dev)
  {
  	const char *path = acpi_device_path(dev->bus->dev);
  	u32 arg;
  
  	if (!path) {
  		path = "\\_SB_.PCI0.LPCB";
  		printk(BIOS_DEBUG, "Using default TPM ACPI path: '%s'\n", path);
  	}
  
  	/* Device */
  	acpigen_write_scope(path);
  	acpigen_write_device(acpi_device_name(dev));
  
  	acpigen_write_name("_HID");
  	acpigen_emit_eisaid("PNP0C31");
  
  	acpigen_write_name("_CID");
  	acpigen_emit_eisaid("PNP0C31");
  
  	acpigen_write_name_integer("_UID", 1);
  
  	u32 did_vid = tpm_read_did_vid(0);
  	if (did_vid > 0 && did_vid < 0xffffffff)
  		acpigen_write_STA(ACPI_STATUS_DEVICE_ALL_ON);
  	else
  		acpigen_write_STA(ACPI_STATUS_DEVICE_ALL_OFF);
  
  	u16 port = dev->path.pnp.port;
  
  	/* Resources */
  	acpigen_write_name("_CRS");
  	acpigen_write_resourcetemplate_header();
  	acpigen_write_mem32fixed(1, CONFIG_TPM_TIS_BASE_ADDRESS, 0x5000);
  	acpigen_write_io16(port, port, 1, 2, 1);
  
  	if (CONFIG_TPM_PIRQ) {
  		/*
  		 * PIRQ: Update interrupt vector with configured PIRQ
  		 * Active-Low Level-Triggered Shared
  		 */
  		struct acpi_irq tpm_irq_a = ACPI_IRQ_LEVEL_LOW(CONFIG_TPM_PIRQ);
  		acpi_device_write_interrupt(&tpm_irq_a);
  	} else if (tpm_read_int_vector(0) > 0) {
  		u8 int_vec = tpm_read_int_vector(0);
  		u8 int_pol = tpm_read_int_polarity(0);
  		struct acpi_irq tpm_irq = ACPI_IRQ_LEVEL_LOW(int_vec);
  
  		if (int_pol & 1)
  			tpm_irq.polarity = ACPI_IRQ_ACTIVE_LOW;
  		else
  			tpm_irq.polarity = ACPI_IRQ_ACTIVE_HIGH;
  
  		if (int_pol & 2)
  			tpm_irq.mode = ACPI_IRQ_EDGE_TRIGGERED;
  		else
  			tpm_irq.mode = ACPI_IRQ_LEVEL_TRIGGERED;
  
  		acpi_device_write_interrupt(&tpm_irq);
  	}
  
  	acpigen_write_resourcetemplate_footer();
  
  	if (!IS_ENABLED(CONFIG_CHROMEOS)) {
  		/*
  		 * _DSM method
  		 */
  		struct dsm_uuid ids[] = {
  			/* Physical presence interface.
  			 * This is used to submit commands like "Clear TPM" to
  			 * be run at next reboot provided that user confirms
  			 * them. Spec allows user to cancel all commands and/or
  			 * configure BIOS to reject commands. So we pretend that
  			 * user did just this: cancelled everything. If user
  			 * really wants to clear TPM the only option now is to
  			 * do it manually in payload.
  			 */
  			DSM_UUID(TPM_PPI_UUID, &tpm_ppi_callbacks[0],
  				ARRAY_SIZE(tpm_ppi_callbacks), (void *) &arg),
  			/* Memory clearing on boot: just a dummy. */
  			DSM_UUID(TPM_MCI_UUID, &tpm_mci_callbacks[0],
  				ARRAY_SIZE(tpm_mci_callbacks), (void *) &arg),
  		};
  
  		acpigen_write_dsm_uuid_arr(ids, ARRAY_SIZE(ids));
  	}
  	acpigen_pop_len(); /* Device */
  	acpigen_pop_len(); /* Scope */
  
  	printk(BIOS_INFO, "%s.%s: %s %s\n", path, acpi_device_name(dev),
  	       dev->chip_ops->name, dev_path(dev));
  }
  
  static const char *lpc_tpm_acpi_name(const struct device *dev)
  {
  	return "TPM";
  }
  #endif
  
  static struct device_operations lpc_tpm_ops = {
  	.read_resources   = &lpc_tpm_read_resources,
  	.set_resources    = &lpc_tpm_set_resources,
  #if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
  	.acpi_name		= &lpc_tpm_acpi_name,
  	.acpi_fill_ssdt_generator = &lpc_tpm_fill_ssdt,
  #endif
  };
  
  static struct pnp_info pnp_dev_info[] = {
  	{ .flags = PNP_IRQ0 }
  };
  
  static void enable_dev(struct device *dev)
  {
  	pnp_enable_devices(dev, &lpc_tpm_ops,
  			   ARRAY_SIZE(pnp_dev_info), pnp_dev_info);
  }
  
  struct chip_operations drivers_pc80_tpm_ops = {
  	CHIP_NAME("LPC TPM")
  	.enable_dev = enable_dev
  };
  
  #endif /* __RAMSTAGE__ */
  