tpm: Add support for new Infineon I2C TPM (SLB 9645 TT 1.2 I2C)

Add support for Infineon's new SLB 9645 TT 1.2 I2C TPMs,
which supports clockstretching, combined reads and a bus speed of
up to 400khz. The device also has a new device id.

This is based on the kernel patch provided by Infineon :
https://gerrit.chromium.org/gerrit/42332

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Tom Wai-Hong Tam <waihong@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>

diff --git a/drivers/tpm/slb9635_i2c/tpm_tis_i2c.c b/drivers/tpm/slb9635_i2c/tpm_tis_i2c.c
index 82a41bf5b272ce2b3f99791c0174a977089f304a..c2e104189a7638e0cbceec6a680993d6062c958b 100644 (file)
--- a/drivers/tpm/slb9635_i2c/tpm_tis_i2c.c
+++ b/drivers/tpm/slb9635_i2c/tpm_tis_i2c.c
@@ -37,12 +37,15 @@
  */
 
 #include <common.h>
+#include <fdtdec.h>
 #include <i2c.h>
 #include <linux/types.h>
 
 #include "compatibility.h"
 #include "tpm.h"
 
+DECLARE_GLOBAL_DATA_PTR;
+
 /* max. buffer size supported by our tpm */
 #ifdef TPM_BUFSIZE
 #undef TPM_BUFSIZE
@@ -65,12 +68,26 @@
 #define SLEEP_DURATION_LONG 210 /* in usec */
 
 /* expected value for DIDVID register */
-#define TPM_TIS_I2C_DID_VID 0x000b15d1L
+#define TPM_TIS_I2C_DID_VID_9635 0x000b15d1L
+#define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
+
+enum i2c_chip_type {
+       SLB9635,
+       SLB9645,
+       UNKNOWN,
+};
+
+static const char * const chip_name[] = {
+       [SLB9635] = "slb9635tt",
+       [SLB9645] = "slb9645tt",
+       [UNKNOWN] = "unknown/fallback to slb9635",
+};
 
 /* Structure to store I2C TPM specific stuff */
 struct tpm_inf_dev {
        uint addr;
        u8 buf[TPM_BUFSIZE + sizeof(u8)];       /* max. buffer size + addr */
+       enum i2c_chip_type chip_type;
 };
 
 static struct tpm_inf_dev tpm_dev = {
@@ -98,27 +115,47 @@ int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
        uint myaddr = addr;
        /* we have to use uint here, uchar hangs the board */
 
-       for (count = 0; count < MAX_COUNT; count++) {
-               rc = i2c_write(tpm_dev.addr, 0, 0, (uchar *)&myaddr, 1);
-               if (rc == 0)
-                       break; /*success, break to skip sleep*/
-
-               udelay(SLEEP_DURATION);
-       }
+       if ((tpm_dev.chip_type == SLB9635) || (tpm_dev.chip_type == UNKNOWN)) {
+               /* slb9635 protocol should work in both cases */
+               for (count = 0; count < MAX_COUNT; count++) {
+                       rc = i2c_write(tpm_dev.addr, 0, 0,
+                                      (uchar *)&myaddr, 1);
+                       if (rc == 0)
+                               break;  /* success, break to skip sleep */
 
-       if (rc)
-               return -rc;
+                       udelay(SLEEP_DURATION);
+               }
 
-       /* After the TPM has successfully received the register address it needs
-        * some time, thus we're sleeping here again, before retrieving the data
-        */
-       for (count = 0; count < MAX_COUNT; count++) {
-               udelay(SLEEP_DURATION);
-               rc = i2c_read(tpm_dev.addr, 0, 0, buffer, len);
-               if (rc == 0)
-                       break; /*success, break to skip sleep*/
+               if (rc)
+                       return -rc;
+
+               /* After the TPM has successfully received the register address
+                * it needs some time, thus we're sleeping here again, before
+                * retrieving the data
+                */
+               for (count = 0; count < MAX_COUNT; count++) {
+                       udelay(SLEEP_DURATION);
+                       rc = i2c_read(tpm_dev.addr, 0, 0, buffer, len);
+                       if (rc == 0)
+                               break;  /* success, break to skip sleep */
+               }
+       } else {
+               /* use a combined read for newer chips
+                * unfortunately the smbus functions are not suitable due to
+                * the 32 byte limit of the smbus.
+                * retries should usually not be needed, but are kept just to
+                * be safe on the safe side.
+                */
+               for (count = 0; count < MAX_COUNT; count++) {
+                       rc = i2c_read(tpm_dev.addr, addr, 1, buffer, len);
+                       if (rc == 0)
+                               break;  /* break here to skip sleep */
+                       udelay(SLEEP_DURATION);
+               }
        }
 
+       /* take care of 'guard time' */
+       udelay(SLEEP_DURATION);
        if (rc)
                return -rc;
 
@@ -139,11 +176,13 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
        for (count = 0; count < max_count; count++) {
                rc = i2c_write(tpm_dev.addr, 0, 0, tpm_dev.buf, len + 1);
                if (rc == 0)
-                       break; /*success, break to skip sleep*/
+                       break;  /* success, break to skip sleep */
 
                udelay(sleep_time);
        }
 
+       /* take care of 'guard time' */
+       udelay(SLEEP_DURATION);
        if (rc)
                return -rc;
 
@@ -490,12 +529,27 @@ static struct tpm_vendor_specific tpm_tis_i2c = {
        .req_canceled = TPM_STS_COMMAND_READY,
 };
 
+static enum i2c_chip_type tpm_vendor_chip_type(void)
+{
+#ifdef CONFIG_OF_CONTROL
+       const void *blob = gd->fdt_blob;
+
+       if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9645_TPM) >= 0)
+               return SLB9645;
+
+       if (fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM) >= 0)
+               return SLB9635;
+#endif
+       return UNKNOWN;
+}
+
 /* initialisation of i2c tpm */
 
 
 int tpm_vendor_init(uint32_t dev_addr)
 {
        u32 vendor;
+       u32 expected_did_vid;
        uint old_addr;
        int rc = 0;
        struct tpm_chip *chip;
@@ -504,6 +558,8 @@ int tpm_vendor_init(uint32_t dev_addr)
        if (dev_addr != 0)
                tpm_dev.addr = dev_addr;
 
+       tpm_dev.chip_type = tpm_vendor_chip_type();
+
        chip = tpm_register_hardware(&tpm_tis_i2c);
        if (chip < 0) {
                rc = -ENODEV;
@@ -530,15 +586,22 @@ int tpm_vendor_init(uint32_t dev_addr)
                goto out_release;
        }
 
-       /* create DID_VID register value, after swapping to little-endian */
-       vendor = be32_to_cpu(vendor);
+       if (tpm_dev.chip_type == SLB9635) {
+               vendor = be32_to_cpu(vendor);
+               expected_did_vid = TPM_TIS_I2C_DID_VID_9635;
+       } else {
+               /* device id and byte order has changed for newer i2c tpms */
+               expected_did_vid = TPM_TIS_I2C_DID_VID_9645;
+       }
 
-       if (vendor != TPM_TIS_I2C_DID_VID) {
+       if (tpm_dev.chip_type != UNKNOWN && vendor != expected_did_vid) {
+               dev_err(dev, "vendor id did not match! ID was %08x\n", vendor);
                rc = -ENODEV;
                goto out_release;
        }
 
-       dev_info(dev, "1.2 TPM (device-id 0x%X)\n", vendor >> 16);
+       dev_info(dev, "1.2 TPM (chip type %s device-id 0x%X)\n",
+                chip_name[tpm_dev.chip_type], vendor >> 16);
 
        /*
         * A timeout query to TPM can be placed here.

diff --git a/drivers/tpm/tis_i2c.c b/drivers/tpm/tis_i2c.c
index e818fbaf541808953c60c62e7b348b7f002b055e..22554e1456b345fa5511131616dec7469d86caa3 100644 (file)
--- a/drivers/tpm/tis_i2c.c
+++ b/drivers/tpm/tis_i2c.c
@@ -67,6 +67,10 @@ static int tpm_decode_config(struct tpm *dev)
        int i2c_bus;
 
        node = fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM);
+       if (node < 0) {
+               node = fdtdec_next_compatible(blob, 0,
+                                             COMPAT_INFINEON_SLB9645_TPM);
+       }
        if (node < 0) {
                debug("%s: Node not found\n", __func__);
                return -1;

diff --git a/include/fdtdec.h b/include/fdtdec.h
index 4e8032ba6cdfd4632ff5bec1a25b793c7defe4ce..1ece6122f5dfa1e0db21b2e4809267b780db1678 100644 (file)
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -93,6 +93,7 @@ enum fdt_compat_id {
        COMPAT_GENERIC_SPI_FLASH,       /* Generic SPI Flash chip */
        COMPAT_MAXIM_98095_CODEC,       /* MAX98095 Codec */
        COMPAT_INFINEON_SLB9635_TPM,    /* Infineon SLB9635 TPM */
+       COMPAT_INFINEON_SLB9645_TPM,    /* Infineon SLB9645 TPM */
 
        COMPAT_COUNT,
 };

diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index ac1fe0be20dc2915038b67318f15d88746e354e1..005ad3d535fbdc32211bd93757858bfce26c411d 100644 (file)
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -66,6 +66,7 @@ static const char * const compat_names[COMPAT_COUNT] = {
        COMPAT(GENERIC_SPI_FLASH, "spi-flash"),
        COMPAT(MAXIM_98095_CODEC, "maxim,max98095-codec"),
        COMPAT(INFINEON_SLB9635_TPM, "infineon,slb9635-tpm"),
+       COMPAT(INFINEON_SLB9645_TPM, "infineon,slb9645-tpm"),
 };
 
 const char *fdtdec_get_compatible(enum fdt_compat_id id)