From: Alexander Steffen <Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org>
To: jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org,
tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: [PATCH v3 2/2] tpm_tis_spi: Use a single buffer for SPI transfers
Date: Thu, 24 Aug 2017 10:27:45 +0200 [thread overview]
Message-ID: <20170824082745.9372-3-Alexander.Steffen@infineon.com> (raw)
In-Reply-To: <20170824082745.9372-1-Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org>
A single buffer is sufficient for both tx and rx, since bytes that have
already been sent are not used anymore and can safely be overwritten with
the received bytes.
Signed-off-by: Alexander Steffen <Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org>
---
drivers/char/tpm/tpm_tis_spi.c | 34 ++++++++++++++--------------------
1 file changed, 14 insertions(+), 20 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index 05ce841..5321245 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -46,9 +46,7 @@
struct tpm_tis_spi_phy {
struct tpm_tis_data priv;
struct spi_device *spi_device;
-
- u8 *tx_buf;
- u8 *rx_buf;
+ u8 *iobuf;
};
static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *data)
@@ -71,14 +69,14 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
while (len) {
transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
- phy->tx_buf[0] = direction | (transfer_len - 1);
- phy->tx_buf[1] = 0xd4;
- phy->tx_buf[2] = addr >> 8;
- phy->tx_buf[3] = addr;
+ phy->iobuf[0] = direction | (transfer_len - 1);
+ phy->iobuf[1] = 0xd4;
+ phy->iobuf[2] = addr >> 8;
+ phy->iobuf[3] = addr;
memset(&spi_xfer, 0, sizeof(spi_xfer));
- spi_xfer.tx_buf = phy->tx_buf;
- spi_xfer.rx_buf = phy->rx_buf;
+ spi_xfer.tx_buf = phy->iobuf;
+ spi_xfer.rx_buf = phy->iobuf;
spi_xfer.len = 4;
spi_xfer.cs_change = 1;
@@ -88,9 +86,9 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
if (ret < 0)
goto exit;
- if ((phy->rx_buf[3] & 0x01) == 0) {
+ if ((phy->iobuf[3] & 0x01) == 0) {
// handle SPI wait states
- phy->tx_buf[0] = 0;
+ phy->iobuf[0] = 0;
for (i = 0; i < TPM_RETRY; i++) {
spi_xfer.len = 1;
@@ -99,7 +97,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
ret = spi_sync_locked(phy->spi_device, &m);
if (ret < 0)
goto exit;
- if (phy->rx_buf[0] & 0x01)
+ if (phy->iobuf[0] & 0x01)
break;
}
@@ -117,7 +115,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
spi_xfer.tx_buf = NULL;
} else {
spi_xfer.rx_buf = NULL;
- memcpy(phy->tx_buf, buffer, transfer_len);
+ memcpy(phy->iobuf, buffer, transfer_len);
}
spi_message_init(&m);
@@ -127,7 +125,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
goto exit;
if (direction)
- memcpy(buffer, phy->rx_buf, transfer_len);
+ memcpy(buffer, phy->iobuf, transfer_len);
len -= transfer_len;
buffer += transfer_len;
@@ -196,12 +194,8 @@ static int tpm_tis_spi_probe(struct spi_device *dev)
phy->spi_device = dev;
- phy->tx_buf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
- if (!phy->tx_buf)
- return -ENOMEM;
-
- phy->rx_buf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
- if (!phy->rx_buf)
+ phy->iobuf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
+ if (!phy->iobuf)
return -ENOMEM;
return tpm_tis_core_init(&dev->dev, &phy->priv, -1, &tpm_spi_phy_ops,
--
2.7.4
------------------------------------------------------------------------------
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next prev parent reply other threads:[~2017-08-24 8:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-24 8:27 [PATCH v3 0/2] tpm_tis_spi: Use DMA-safe memory Alexander Steffen
[not found] ` <20170824082745.9372-1-Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org>
2017-08-24 8:27 ` [PATCH v3 1/2] tpm_tis_spi: Use DMA-safe memory for SPI transfers Alexander Steffen
2017-08-25 16:39 ` Jarkko Sakkinen
2017-08-24 8:27 ` Alexander Steffen [this message]
[not found] ` <20170824082745.9372-3-Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w@public.gmane.org>
2017-08-25 16:39 ` [PATCH v3 2/2] tpm_tis_spi: Use a single buffer " Jarkko Sakkinen
2017-08-26 11:22 ` [PATCH v3 0/2] tpm_tis_spi: Use DMA-safe memory Jarkko Sakkinen
[not found] ` <20170826112259.ypwtqbwakyfdqkzo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2017-08-29 12:14 ` Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w
[not found] ` <9aea582eccbe4655b5de487dacf7c745-nFblLGNE8XKJSz+rYg/bSJowlv4uC7bZ@public.gmane.org>
2017-08-30 8:42 ` Benoit HOUYERE
[not found] ` <fe81962beaec4c6fa21ea90df0f01560-tklXXlf0F76qZDvoWP1BVkEOCMrvLtNR@public.gmane.org>
2017-08-31 12:34 ` Alexander.Steffen-d0qZbvYSIPpWk0Htik3J/w
2017-08-30 10:08 ` Jarkko Sakkinen
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