diff mbox series

[V6,3/3] spi: tegra210-quad: Enable TPM wait polling

Message ID 20230227172108.8206-4-kyarlagadda@nvidia.com (mailing list archive)
State Superseded
Headers show
Series Tegra TPM driver with HW flow control | expand

Commit Message

Krishna Yarlagadda Feb. 27, 2023, 5:21 p.m. UTC
Trusted Platform Module requires flow control. As defined in TPM
interface specification, client would drive MISO line at same cycle as
last address bit on MOSI.
Tegra241 QSPI controller has TPM wait state detection feature which is
enabled for TPM client devices reported in SPI device mode bits.
Set half duplex flag for TPM device to detect and send entire message
to controller in one shot.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 drivers/spi/spi-tegra210-quad.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Thierry Reding March 1, 2023, 1:39 p.m. UTC | #1
On Mon, Feb 27, 2023 at 10:51:08PM +0530, Krishna Yarlagadda wrote:
> Trusted Platform Module requires flow control. As defined in TPM
> interface specification, client would drive MISO line at same cycle as
> last address bit on MOSI.
> Tegra241 QSPI controller has TPM wait state detection feature which is
> enabled for TPM client devices reported in SPI device mode bits.
> Set half duplex flag for TPM device to detect and send entire message
> to controller in one shot.
> 
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
>  drivers/spi/spi-tegra210-quad.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)

Acked-by: Thierry Reding <treding@nvidia.com>
Thierry Reding March 1, 2023, 1:41 p.m. UTC | #2
On Mon, Feb 27, 2023 at 10:51:08PM +0530, Krishna Yarlagadda wrote:
> Trusted Platform Module requires flow control. As defined in TPM
> interface specification, client would drive MISO line at same cycle as
> last address bit on MOSI.
> Tegra241 QSPI controller has TPM wait state detection feature which is
> enabled for TPM client devices reported in SPI device mode bits.
> Set half duplex flag for TPM device to detect and send entire message
> to controller in one shot.
> 
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
>  drivers/spi/spi-tegra210-quad.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
> index b967576b6c96..e1165584a20a 100644
> --- a/drivers/spi/spi-tegra210-quad.c
> +++ b/drivers/spi/spi-tegra210-quad.c
> @@ -142,6 +142,7 @@
>  
>  #define QSPI_GLOBAL_CONFIG			0X1a4
>  #define QSPI_CMB_SEQ_EN				BIT(0)
> +#define QSPI_TPM_WAIT_POLL_EN			BIT(1)
>  
>  #define QSPI_CMB_SEQ_ADDR			0x1a8
>  #define QSPI_ADDRESS_VALUE_SET(X)		(((x) & 0xFFFF) << 0)
> @@ -164,6 +165,7 @@
>  struct tegra_qspi_soc_data {
>  	bool has_dma;
>  	bool cmb_xfer_capable;
> +	bool support_tpm;

Nit: this could be "supports_tpm" for slightly more consistency with
"has_dma".

Thierry
Jon Hunter March 1, 2023, 1:51 p.m. UTC | #3
On 27/02/2023 17:21, Krishna Yarlagadda wrote:
> Trusted Platform Module requires flow control. As defined in TPM
> interface specification, client would drive MISO line at same cycle as
> last address bit on MOSI.
> Tegra241 QSPI controller has TPM wait state detection feature which is
> enabled for TPM client devices reported in SPI device mode bits.

Earlier in patch 2/3 we say Tegra234 and Tegra241 but here we just say 
Tegra241.

>   static struct tegra_qspi_soc_data tegra186_qspi_soc_data = {
>   	.has_dma = true,
>   	.cmb_xfer_capable = true,
> +	.support_tpm = false,
>   	.cs_count = 1,
>   };
>   
>   static struct tegra_qspi_soc_data tegra234_qspi_soc_data = {
>   	.has_dma = false,
>   	.cmb_xfer_capable = true,
> +	.support_tpm = true,
>   	.cs_count = 1,
>   };
>   
>   static struct tegra_qspi_soc_data tegra241_qspi_soc_data = {
>   	.has_dma = false,
>   	.cmb_xfer_capable = true,
> +	.support_tpm = true,
>   	.cs_count = 4,
>   };
>   

We enable for both Tegra234 and Tegra241 and so the commit message 
should say so.

Jon
diff mbox series

Patch

diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c
index b967576b6c96..e1165584a20a 100644
--- a/drivers/spi/spi-tegra210-quad.c
+++ b/drivers/spi/spi-tegra210-quad.c
@@ -142,6 +142,7 @@ 
 
 #define QSPI_GLOBAL_CONFIG			0X1a4
 #define QSPI_CMB_SEQ_EN				BIT(0)
+#define QSPI_TPM_WAIT_POLL_EN			BIT(1)
 
 #define QSPI_CMB_SEQ_ADDR			0x1a8
 #define QSPI_ADDRESS_VALUE_SET(X)		(((x) & 0xFFFF) << 0)
@@ -164,6 +165,7 @@ 
 struct tegra_qspi_soc_data {
 	bool has_dma;
 	bool cmb_xfer_capable;
+	bool support_tpm;
 	unsigned int cs_count;
 };
 
@@ -1065,6 +1067,12 @@  static int tegra_qspi_combined_seq_xfer(struct tegra_qspi *tqspi,
 
 	/* Enable Combined sequence mode */
 	val = tegra_qspi_readl(tqspi, QSPI_GLOBAL_CONFIG);
+	if (spi->mode & SPI_TPM_HW_FLOW) {
+		if (tqspi->soc_data->support_tpm)
+			val |= QSPI_TPM_WAIT_POLL_EN;
+		else
+			return -EIO;
+	}
 	val |= QSPI_CMB_SEQ_EN;
 	tegra_qspi_writel(tqspi, val, QSPI_GLOBAL_CONFIG);
 	/* Process individual transfer list */
@@ -1192,6 +1200,8 @@  static int tegra_qspi_non_combined_seq_xfer(struct tegra_qspi *tqspi,
 	/* Disable Combined sequence mode */
 	val = tegra_qspi_readl(tqspi, QSPI_GLOBAL_CONFIG);
 	val &= ~QSPI_CMB_SEQ_EN;
+	if (tqspi->soc_data->support_tpm)
+		val &= ~QSPI_TPM_WAIT_POLL_EN;
 	tegra_qspi_writel(tqspi, val, QSPI_GLOBAL_CONFIG);
 	list_for_each_entry(transfer, &msg->transfers, transfer_list) {
 		struct spi_transfer *xfer = transfer;
@@ -1450,24 +1460,28 @@  static irqreturn_t tegra_qspi_isr_thread(int irq, void *context_data)
 static struct tegra_qspi_soc_data tegra210_qspi_soc_data = {
 	.has_dma = true,
 	.cmb_xfer_capable = false,
+	.support_tpm = false,
 	.cs_count = 1,
 };
 
 static struct tegra_qspi_soc_data tegra186_qspi_soc_data = {
 	.has_dma = true,
 	.cmb_xfer_capable = true,
+	.support_tpm = false,
 	.cs_count = 1,
 };
 
 static struct tegra_qspi_soc_data tegra234_qspi_soc_data = {
 	.has_dma = false,
 	.cmb_xfer_capable = true,
+	.support_tpm = true,
 	.cs_count = 1,
 };
 
 static struct tegra_qspi_soc_data tegra241_qspi_soc_data = {
 	.has_dma = false,
 	.cmb_xfer_capable = true,
+	.support_tpm = true,
 	.cs_count = 4,
 };