[PATCH v4 4/6] tpm: tpm_tis_spi: Export functionality to other drivers

Stephen Boyd
2019-08-12T22:36:33Z

Export a new function, tpm_tis_spi_init(), and the associated
read/write/transfer APIs so that we can create variant drivers based on
the core functionality of this TPM SPI driver. Variant drivers can wrap
the tpm_tis_spi_phy struct with their own struct and override the
behavior of tpm_tis_spi_transfer() by supplying their own flow control
and pre-transfer hooks. This shares the most code between the core
driver and any variants that want to override certain behavior without
cluttering the core driver.

Cc: Andrey Pronin <apronin@chromium.org>
Cc: Duncan Laurie <dlaurie@chromium.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
drivers/char/tpm/tpm_tis_spi.c | 52 ++++++++++++++++------------------
drivers/char/tpm/tpm_tis_spi.h | 37 ++++++++++++++++++++++++
2 files changed, 62 insertions(+), 27 deletions(-)
create mode 100644 drivers/char/tpm/tpm_tis_spi.h

diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index 93f49b1941f0..fd3fb4f9f506 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -36,23 +36,10 @@
#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;
- int (*flow_control)(struct tpm_tis_spi_phy *phy,
- struct spi_transfer *xfer);
- void (*pre_transfer)(struct tpm_tis_spi_phy *phy);
- u8 *iobuf;
-};
-
-static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *data)
-{
- return container_of(data, struct tpm_tis_spi_phy, priv);
-}
-
static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
struct spi_transfer *spi_xfer)
{
@@ -81,7 +68,7 @@ static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
return 0;
}

-static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
+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);
@@ -148,9 +135,10 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
spi_bus_unlock(phy->spi_device->master);
return ret;
}
+EXPORT_SYMBOL_GPL(tpm_tis_spi_transfer);

-static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
- u16 len, u8 *result)
+static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
+ u8 *result)
{
return tpm_tis_spi_transfer(data, addr, len, result, NULL);
}
@@ -161,7 +149,7 @@ 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;
@@ -173,8 +161,9 @@ static int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)

return rc;
}
+EXPORT_SYMBOL_GPL(tpm_tis_spi_read16);

-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;
@@ -186,8 +175,9 @@ static int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)

return rc;
}
+EXPORT_SYMBOL_GPL(tpm_tis_spi_read32);

-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;
@@ -198,6 +188,20 @@ static int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)

return rc;
}
+EXPORT_SYMBOL_GPL(tpm_tis_spi_write32);
+
+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);
+}
+EXPORT_SYMBOL_GPL(tpm_tis_spi_init);

static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
.read_bytes = tpm_tis_spi_read_bytes,
@@ -217,11 +221,6 @@ 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 */
@@ -230,8 +229,7 @@ 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);
+ return tpm_tis_spi_init(dev, phy, irq, &tpm_spi_phy_ops);
}

static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
diff --git a/drivers/char/tpm/tpm_tis_spi.h b/drivers/char/tpm/tpm_tis_spi.h
new file mode 100644
index 000000000000..48be5130794a
--- /dev/null
+++ b/drivers/char/tpm/tpm_tis_spi.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2015 Infineon Technologies AG
+ * Copyright (C) 2016 STMicroelectronics SAS
+ */
+
+#ifndef TPM_TIS_SPI_H
+#define TPM_TIS_SPI_H
+
+#include "tpm_tis_core.h"
+
+struct tpm_tis_spi_phy {
+ struct tpm_tis_data priv;
+ struct spi_device *spi_device;
+ int (*flow_control)(struct tpm_tis_spi_phy *phy,
+ struct spi_transfer *xfer);
+ void (*pre_transfer)(struct tpm_tis_spi_phy *phy);
+
+ u8 *iobuf;
+};
+
+static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *data)
+{
+ return container_of(data, struct tpm_tis_spi_phy, priv);
+}
+
+extern 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);
+
+extern int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
+ u8 *in, const u8 *out);
+
+extern int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result);
+extern int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result);
+extern int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value);
+
+#endif
--
Sent by a computer through tubes