From 67a142dc9eb96a5cc018e5db62390665eb5f038c Mon Sep 17 00:00:00 2001 From: Krishna Yarlagadda Date: Fri, 21 Apr 2023 14:43:07 +0530 Subject: spi: Add TPM HW flow flag TPM specification [1] defines flow control over SPI. Client device can insert a wait state on MISO when address is transmitted by controller on MOSI. Detecting the wait state in software is only possible for full duplex controllers. For controllers that support only half- duplex, the wait state detection needs to be implemented in hardware. Add a flag SPI_TPM_HW_FLOW for TPM device to set when software flow control is not possible and hardware flow control is expected from SPI controller. Reference: [1] https://trustedcomputinggroup.org/resource/pc-client-platform-tpm -profile-ptp-specification/ Signed-off-by: Krishna Yarlagadda Reviewed-by: Jerry Snitselaar Link: https://lore.kernel.org/r/20230421091309.2672-2-kyarlagadda@nvidia.com Signed-off-by: Mark Brown --- include/linux/spi/spi.h | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 873ced6ae4ca..cfe42f8cd7a4 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -184,8 +184,18 @@ 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 */ + /* + * TPM specification defines flow control over SPI. Client device + * can insert a wait state on MISO when address is transmitted by + * controller on MOSI. Detecting the wait state in software is only + * possible for full duplex controllers. For controllers that support + * only half-duplex, the wait state detection needs to be implemented + * in hardware. TPM devices would set this flag when hardware flow + * control is expected from SPI controller. + */ +#define SPI_TPM_HW_FLOW BIT(29) /* TPM HW 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 +205,7 @@ 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; -- cgit From 967ca91a996f82219f2883e9e53d8e20df49025a Mon Sep 17 00:00:00 2001 From: Krishna Yarlagadda Date: Fri, 21 Apr 2023 14:43:09 +0530 Subject: spi: tegra210-quad: Enable TPM wait polling 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. Tegra234 and Tegra241 QSPI controllers have TPM wait state detection feature which is enabled for TPM client devices reported in SPI device mode bits. Signed-off-by: Krishna Yarlagadda Reviewed-by: Jon Hunter Reviewed-by: Jerry Snitselaar Link: https://lore.kernel.org/r/20230421091309.2672-4-kyarlagadda@nvidia.com Signed-off-by: Mark Brown --- 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 bea376acea1f..fbd14dd7be44 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 supports_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->supports_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 */ @@ -1196,6 +1204,8 @@ 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->supports_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; @@ -1454,24 +1464,28 @@ 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, + .supports_tpm = false, .cs_count = 1, }; static struct tegra_qspi_soc_data tegra186_qspi_soc_data = { .has_dma = true, .cmb_xfer_capable = true, + .supports_tpm = false, .cs_count = 1, }; static struct tegra_qspi_soc_data tegra234_qspi_soc_data = { .has_dma = false, .cmb_xfer_capable = true, + .supports_tpm = true, .cs_count = 1, }; static struct tegra_qspi_soc_data tegra241_qspi_soc_data = { .has_dma = false, .cmb_xfer_capable = true, + .supports_tpm = true, .cs_count = 4, }; -- cgit