From: Krishna Yarlagadda <kyarlagadda@nvidia.com>
To: <robh+dt@kernel.org>, <broonie@kernel.org>, <peterhuewe@gmx.de>,
<jgg@ziepe.ca>, <jarkko@kernel.org>,
<krzysztof.kozlowski+dt@linaro.org>, <linux-spi@vger.kernel.org>,
<linux-tegra@vger.kernel.org>, <linux-integrity@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
<skomatineni@nvidia.com>, <ldewangan@nvidia.com>,
Krishna Yarlagadda <kyarlagadda@nvidia.com>
Subject: [Patch V6 1/3] spi: Add TPM HW flow flag
Date: Mon, 27 Feb 2023 22:51:06 +0530 [thread overview]
Message-ID: <20230227172108.8206-2-kyarlagadda@nvidia.com> (raw)
In-Reply-To: <20230227172108.8206-1-kyarlagadda@nvidia.com>
TPM spec defines flow control over SPI. Client device can insert a wait
state on MISO when address is trasmitted by controller on MOSI. It can
work only on full duplex.
Half duplex controllers need to implement flow control in HW.
Add a flag for TPM to indicate flow control is expected in controller.
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
include/linux/spi/spi.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 4fa26b9a3572..6b32c90e9e20 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -184,8 +184,9 @@ struct spi_device {
u8 chip_select;
u8 bits_per_word;
bool rt;
-#define SPI_NO_TX BIT(31) /* No transmit wire */
-#define SPI_NO_RX BIT(30) /* No receive wire */
+#define SPI_NO_TX BIT(31) /* No transmit wire */
+#define SPI_NO_RX BIT(30) /* No receive wire */
+#define SPI_TPM_HW_FLOW BIT(29) /* TPM flow control */
/*
* All bits defined above should be covered by SPI_MODE_KERNEL_MASK.
* The SPI_MODE_KERNEL_MASK has the SPI_MODE_USER_MASK counterpart,
@@ -195,7 +196,7 @@ struct spi_device {
* These bits must not overlap. A static assert check should make sure of that.
* If adding extra bits, make sure to decrease the bit index below as well.
*/
-#define SPI_MODE_KERNEL_MASK (~(BIT(30) - 1))
+#define SPI_MODE_KERNEL_MASK (~(BIT(29) - 1))
u32 mode;
int irq;
void *controller_state;
--
2.17.1
next prev parent reply other threads:[~2023-02-27 17:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-27 17:21 [Patch V6 0/3] Tegra TPM driver with HW flow control Krishna Yarlagadda
2023-02-27 17:21 ` Krishna Yarlagadda [this message]
2023-03-01 13:34 ` [Patch V6 1/3] spi: Add TPM HW flow flag Thierry Reding
2023-03-01 15:27 ` Krishna Yarlagadda
2023-02-27 17:21 ` [Patch V6 2/3] tpm_tis-spi: Support hardware wait polling Krishna Yarlagadda
2023-03-01 13:37 ` Thierry Reding
2023-02-27 17:21 ` [Patch V6 3/3] spi: tegra210-quad: Enable TPM " Krishna Yarlagadda
2023-03-01 13:39 ` Thierry Reding
2023-03-01 13:41 ` Thierry Reding
2023-03-01 13:51 ` Jon Hunter
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