Hi Jarkko,
Am 09.09.24 um 19:05 schrieb Jarkko Sakkinen:
On Fri Sep 6, 2024 at 5:46 PM EEST, Stefan Wahren wrote:
Am 06.09.24 um 11:47 schrieb Jarkko Sakkinen:
On Fri Sep 6, 2024 at 9:09 AM EEST, Stefan Wahren wrote:
According to TCG PC Client Platform TPM Profile (PTP) Specification
only SPI mode 0 is supported. In order to ensure the SPI controller
supports the necessary settings, call spi_setup() and bail out
as soon as possible in error case.
This change should affect all supported TPM SPI devices, because
tpm_tis_spi_probe is either called direct or indirectly.
Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
---
drivers/char/tpm/tpm_tis_spi_main.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
index 61b42c83ced8..e62d297b040e 100644
--- a/drivers/char/tpm/tpm_tis_spi_main.c
+++ b/drivers/char/tpm/tpm_tis_spi_main.c
@@ -248,6 +248,17 @@ static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
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)
{
+ int ret;
+
+ spi->mode &= ~SPI_MODE_X_MASK;
+ spi->mode |= SPI_MODE_0;
+
+ ret = spi_setup(spi);
+ if (ret < 0) {
+ dev_err(&spi->dev, "SPI setup failed: %d\n", ret);
+ return ret;
+ }
+
phy->iobuf = devm_kmalloc(&spi->dev, SPI_HDRSIZE + MAX_SPI_FRAMESIZE, GFP_KERNEL);
if (!phy->iobuf)
return -ENOMEM;
--
2.34.1
Why?
SPI protocol driver usually call spi_setup to verify that the SPI
controller accept the settings (SPI mode, bit, clock rate ...). Bailing
out early is more helpful for debugging issues.
What problem has this patch solved for you? I think it makes the code
only less robust and more error prone.
this is not a fix for an issue i was experiencing.
It is just an improvement to catch possible invalid settings which has
been passed via DT device for example or the SPI controller doesn't
support SPI mode 0.
BR, Jarkko
