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path: root/drivers/char/tpm/tpm_tis_spi.c
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Diffstat (limited to 'drivers/char/tpm/tpm_tis_spi.c')
-rw-r--r--drivers/char/tpm/tpm_tis_spi.c143
1 files changed, 87 insertions, 56 deletions
diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index 19513e622053..d1754fd6c573 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -20,42 +20,64 @@
* Dorn and Kyleen Hall and Jarko Sakkinnen.
*/
+#include <linux/acpi.h>
+#include <linux/completion.h>
#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/moduleparam.h>
#include <linux/slab.h>
-#include <linux/interrupt.h>
-#include <linux/wait.h>
-#include <linux/acpi.h>
-#include <linux/freezer.h>
+#include <linux/of_device.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 "tpm.h"
#include "tpm_tis_core.h"
+#include "tpm_tis_spi.h"
#define MAX_SPI_FRAMESIZE 64
-struct tpm_tis_spi_phy {
- struct tpm_tis_data priv;
- struct spi_device *spi_device;
- u8 *iobuf;
-};
-
-static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *data)
+/*
+ * TCG SPI flow control is documented in section 6.4 of the spec[1]. In short,
+ * keep trying to read from the device until MISO goes high indicating the
+ * wait state has ended.
+ *
+ * [1] https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
+ */
+static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
+ struct spi_transfer *spi_xfer)
{
- return container_of(data, struct tpm_tis_spi_phy, priv);
+ struct spi_message m;
+ int ret, i;
+
+ if ((phy->iobuf[3] & 0x01) == 0) {
+ // handle SPI wait states
+ phy->iobuf[0] = 0;
+
+ for (i = 0; i < TPM_RETRY; i++) {
+ spi_xfer->len = 1;
+ spi_message_init(&m);
+ spi_message_add_tail(spi_xfer, &m);
+ ret = spi_sync_locked(phy->spi_device, &m);
+ if (ret < 0)
+ return ret;
+ if (phy->iobuf[0] & 0x01)
+ break;
+ }
+
+ if (i == TPM_RETRY)
+ return -ETIMEDOUT;
+ }
+
+ return 0;
}
-static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
- u8 *in, const u8 *out)
+int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
+ u8 *in, const u8 *out)
{
struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
int ret = 0;
- int i;
struct spi_message m;
struct spi_transfer spi_xfer;
u8 transfer_len;
@@ -82,26 +104,9 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
if (ret < 0)
goto exit;
- if ((phy->iobuf[3] & 0x01) == 0) {
- // handle SPI wait states
- phy->iobuf[0] = 0;
-
- for (i = 0; i < TPM_RETRY; i++) {
- spi_xfer.len = 1;
- spi_message_init(&m);
- spi_message_add_tail(&spi_xfer, &m);
- ret = spi_sync_locked(phy->spi_device, &m);
- if (ret < 0)
- goto exit;
- if (phy->iobuf[0] & 0x01)
- break;
- }
-
- if (i == TPM_RETRY) {
- ret = -ETIMEDOUT;
- goto exit;
- }
- }
+ ret = phy->flow_control(phy, &spi_xfer);
+ if (ret < 0)
+ goto exit;
spi_xfer.cs_change = 0;
spi_xfer.len = transfer_len;
@@ -117,6 +122,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
spi_message_init(&m);
spi_message_add_tail(&spi_xfer, &m);
+ reinit_completion(&phy->ready);
ret = spi_sync_locked(phy->spi_device, &m);
if (ret < 0)
goto exit;
@@ -146,7 +152,7 @@ static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
return tpm_tis_spi_transfer(data, addr, len, NULL, value);
}
-static int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
+int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
{
__le16 result_le;
int rc;
@@ -159,7 +165,7 @@ static int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
return rc;
}
-static int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
+int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
{
__le32 result_le;
int rc;
@@ -172,7 +178,7 @@ static int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
return rc;
}
-static int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)
+int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)
{
__le32 value_le;
int rc;
@@ -184,6 +190,18 @@ static int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)
return rc;
}
+int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,
+ int irq, const struct tpm_tis_phy_ops *phy_ops)
+{
+ phy->iobuf = devm_kmalloc(&spi->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
+ if (!phy->iobuf)
+ return -ENOMEM;
+
+ phy->spi_device = spi;
+
+ return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL);
+}
+
static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
.read_bytes = tpm_tis_spi_read_bytes,
.write_bytes = tpm_tis_spi_write_bytes,
@@ -202,11 +220,7 @@ static int tpm_tis_spi_probe(struct spi_device *dev)
if (!phy)
return -ENOMEM;
- phy->spi_device = dev;
-
- phy->iobuf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
- if (!phy->iobuf)
- return -ENOMEM;
+ phy->flow_control = tpm_tis_spi_flow_control;
/* If the SPI device has an IRQ then use that */
if (dev->irq > 0)
@@ -214,11 +228,27 @@ static int tpm_tis_spi_probe(struct spi_device *dev)
else
irq = -1;
- return tpm_tis_core_init(&dev->dev, &phy->priv, irq, &tpm_spi_phy_ops,
- NULL);
+ init_completion(&phy->ready);
+ return tpm_tis_spi_init(dev, phy, irq, &tpm_spi_phy_ops);
+}
+
+typedef int (*tpm_tis_spi_probe_func)(struct spi_device *);
+
+static int tpm_tis_spi_driver_probe(struct spi_device *spi)
+{
+ const struct spi_device_id *spi_dev_id = spi_get_device_id(spi);
+ tpm_tis_spi_probe_func probe_func;
+
+ probe_func = of_device_get_match_data(&spi->dev);
+ if (!probe_func && spi_dev_id)
+ probe_func = (tpm_tis_spi_probe_func)spi_dev_id->driver_data;
+ if (!probe_func)
+ return -ENODEV;
+
+ return probe_func(spi);
}
-static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
+static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_spi_resume);
static int tpm_tis_spi_remove(struct spi_device *dev)
{
@@ -230,15 +260,17 @@ static int tpm_tis_spi_remove(struct spi_device *dev)
}
static const struct spi_device_id tpm_tis_spi_id[] = {
- {"tpm_tis_spi", 0},
+ { "tpm_tis_spi", (unsigned long)tpm_tis_spi_probe },
+ { "cr50", (unsigned long)cr50_spi_probe },
{}
};
MODULE_DEVICE_TABLE(spi, tpm_tis_spi_id);
static const struct of_device_id of_tis_spi_match[] = {
- { .compatible = "st,st33htpm-spi", },
- { .compatible = "infineon,slb9670", },
- { .compatible = "tcg,tpm_tis-spi", },
+ { .compatible = "st,st33htpm-spi", .data = tpm_tis_spi_probe },
+ { .compatible = "infineon,slb9670", .data = tpm_tis_spi_probe },
+ { .compatible = "tcg,tpm_tis-spi", .data = tpm_tis_spi_probe },
+ { .compatible = "google,cr50", .data = cr50_spi_probe },
{}
};
MODULE_DEVICE_TABLE(of, of_tis_spi_match);
@@ -251,13 +283,12 @@ MODULE_DEVICE_TABLE(acpi, acpi_tis_spi_match);
static struct spi_driver tpm_tis_spi_driver = {
.driver = {
- .owner = THIS_MODULE,
.name = "tpm_tis_spi",
.pm = &tpm_tis_pm,
.of_match_table = of_match_ptr(of_tis_spi_match),
.acpi_match_table = ACPI_PTR(acpi_tis_spi_match),
},
- .probe = tpm_tis_spi_probe,
+ .probe = tpm_tis_spi_driver_probe,
.remove = tpm_tis_spi_remove,
.id_table = tpm_tis_spi_id,
};
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-26 14:50:48 +0300