[PATCH 2/4] tpm: tegra: Support SPI tpm wait state detect

[Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>]

Tegra234 and Tegra241 chips have QSPI controller that supports TCG
TIS hardware flow control. Since the controller only supports half
duplex, sw wait polling method implemented in tpm_tis_spi does not
suffice. Added extending driver to disable sw flow control and send
all transfers in single message.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>
---
 drivers/char/tpm/Makefile            |   1 +
 drivers/char/tpm/tpm_tis_spi.h       |   1 +
 drivers/char/tpm/tpm_tis_spi_main.c  |   4 +-
 drivers/char/tpm/tpm_tis_spi_tegra.c | 123 +++++++++++++++++++++++++++
 4 files changed, 128 insertions(+), 1 deletion(-)
 create mode 100644 drivers/char/tpm/tpm_tis_spi_tegra.c

diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 0222b1ddb310..445b15493cb3 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_TCG_TIS_SYNQUACER) += tpm_tis_synquacer.o
 
 obj-$(CONFIG_TCG_TIS_SPI) += tpm_tis_spi.o
 tpm_tis_spi-y := tpm_tis_spi_main.o
+tpm_tis_spi-y += tpm_tis_spi_tegra.o
 tpm_tis_spi-$(CONFIG_TCG_TIS_SPI_CR50) += tpm_tis_spi_cr50.o
 
 obj-$(CONFIG_TCG_TIS_I2C_CR50) += tpm_tis_i2c_cr50.o
diff --git a/drivers/char/tpm/tpm_tis_spi.h b/drivers/char/tpm/tpm_tis_spi.h
index d0f66f6f1931..feaea14b428b 100644
--- a/drivers/char/tpm/tpm_tis_spi.h
+++ b/drivers/char/tpm/tpm_tis_spi.h
@@ -31,6 +31,7 @@ extern int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,
 extern int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
 				u8 *in, const u8 *out);
 
+extern int tegra_tpm_spi_probe(struct spi_device *spi);
 #ifdef CONFIG_TCG_TIS_SPI_CR50
 extern int cr50_spi_probe(struct spi_device *spi);
 #else
diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
index a0963a3e92bd..5d4502a4461a 100644
--- a/drivers/char/tpm/tpm_tis_spi_main.c
+++ b/drivers/char/tpm/tpm_tis_spi_main.c
@@ -198,7 +198,7 @@ static int tpm_tis_spi_driver_probe(struct spi_device *spi)
 	const struct spi_device_id *spi_dev_id = spi_get_device_id(spi);
 	tpm_tis_spi_probe_func probe_func;
 
-	probe_func = of_device_get_match_data(&spi->dev);
+	probe_func = device_get_match_data(&spi->dev);
 	if (!probe_func) {
 		if (spi_dev_id) {
 			probe_func = (tpm_tis_spi_probe_func)spi_dev_id->driver_data;
@@ -227,6 +227,7 @@ static const struct spi_device_id tpm_tis_spi_id[] = {
 	{ "tpm_tis_spi", (unsigned long)tpm_tis_spi_probe },
 	{ "tpm_tis-spi", (unsigned long)tpm_tis_spi_probe },
 	{ "cr50", (unsigned long)cr50_spi_probe },
+	{ "tegra-tpm-spi", (unsigned long)tegra_tpm_spi_probe },
 	{}
 };
 MODULE_DEVICE_TABLE(spi, tpm_tis_spi_id);
@@ -236,6 +237,7 @@ static const struct of_device_id of_tis_spi_match[] = {
 	{ .compatible = "infineon,slb9670", .data = tpm_tis_spi_probe },
 	{ .compatible = "tcg,tpm_tis-spi", .data = tpm_tis_spi_probe },
 	{ .compatible = "google,cr50", .data = cr50_spi_probe },
+	{ .compatible = "nvidia,tegra-tpm-spi", .data = tegra_tpm_spi_probe },
 	{}
 };
 MODULE_DEVICE_TABLE(of, of_tis_spi_match);
diff --git a/drivers/char/tpm/tpm_tis_spi_tegra.c b/drivers/char/tpm/tpm_tis_spi_tegra.c
new file mode 100644
index 000000000000..23f20684513d
--- /dev/null
+++ b/drivers/char/tpm/tpm_tis_spi_tegra.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 NVIDIA CORPORATION.
+ *
+ * This device driver implements TEGRA QSPI hw wait detection for chips
+ *
+ * It is based on tpm_tis_spi driver by Peter Huewe and Christophe Ricard.
+ */
+
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/spi/spi.h>
+#include <linux/wait.h>
+
+#include "tpm_tis_core.h"
+#include "tpm_tis_spi.h"
+
+#define MAX_SPI_FRAMESIZE 64
+
+int tpm_tis_spi_tegra_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
+			       u8 *in, const u8 *out)
+{
+	struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
+	int ret = 0;
+	struct spi_message m;
+	struct spi_transfer spi_xfer[3];
+	u8 transfer_len;
+
+	spi_bus_lock(phy->spi_device->master);
+
+	while (len) {
+		transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
+
+		spi_message_init(&m);
+		phy->iobuf[0] = (in ? 0x80 : 0) | (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[0].tx_buf = phy->iobuf;
+		spi_xfer[0].len = 1;
+		spi_message_add_tail(&spi_xfer[0], &m);
+
+		spi_xfer[1].tx_buf = phy->iobuf + 1;
+		spi_xfer[1].len = 3;
+		spi_message_add_tail(&spi_xfer[1], &m);
+
+		if (out) {
+			spi_xfer[2].tx_buf = &phy->iobuf[4];
+			spi_xfer[2].rx_buf = NULL;
+			memcpy(&phy->iobuf[4], out, transfer_len);
+			out += transfer_len;
+		}
+		if (in) {
+			spi_xfer[2].tx_buf = NULL;
+			spi_xfer[2].rx_buf = &phy->iobuf[4];
+		}
+		spi_xfer[2].len = transfer_len;
+		spi_message_add_tail(&spi_xfer[2], &m);
+
+		reinit_completion(&phy->ready);
+		ret = spi_sync_locked(phy->spi_device, &m);
+		if (ret < 0)
+			goto exit;
+
+		if (in) {
+			memcpy(in, &phy->iobuf[4], transfer_len);
+			in += transfer_len;
+		}
+
+		len -= transfer_len;
+	}
+
+exit:
+	spi_bus_unlock(phy->spi_device->master);
+	return ret;
+}
+
+static int tpm_tis_spi_tegra_read_bytes(struct tpm_tis_data *data, u32 addr,
+					u16 len, u8 *result,
+					enum tpm_tis_io_mode io_mode)
+{
+	return tpm_tis_spi_tegra_transfer(data, addr, len, result, NULL);
+}
+
+static int tpm_tis_spi_tegra_write_bytes(struct tpm_tis_data *data, u32 addr,
+					 u16 len, const u8 *value,
+					 enum tpm_tis_io_mode io_mode)
+{
+	return tpm_tis_spi_tegra_transfer(data, addr, len, NULL, value);
+}
+
+static const struct tpm_tis_phy_ops tegra_tpm_spi_phy_ops = {
+	.read_bytes = tpm_tis_spi_tegra_read_bytes,
+	.write_bytes = tpm_tis_spi_tegra_write_bytes,
+};
+
+int tegra_tpm_spi_probe(struct spi_device *dev)
+{
+	struct tpm_tis_spi_phy *phy;
+	int irq;
+
+	phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
+			   GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->flow_control = NULL;
+
+	/* If the SPI device has an IRQ then use that */
+	if (dev->irq > 0)
+		irq = dev->irq;
+	else
+		irq = -1;
+
+	init_completion(&phy->ready);
+	return tpm_tis_spi_init(dev, phy, irq, &tegra_tpm_spi_phy_ops);
+}
-- 
2.17.1