hw/nvram: Add BCM2835 OTP device

The OTP device registers are currently stubbed. For now, the device
houses the OTP rows which will be accessed directly by other peripherals.

Signed-off-by: Rayhan Faizel <rayhan.faizel@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/include/hw/nvram/bcm2835_otp.h b/include/hw/nvram/bcm2835_otp.h
new file mode 100644
index 0000000..1df3370
--- /dev/null
+++ b/include/hw/nvram/bcm2835_otp.h
@@ -0,0 +1,68 @@
+/*
+ * BCM2835 One-Time Programmable (OTP) Memory
+ *
+ * Copyright (c) 2024 Rayhan Faizel <rayhan.faizel@gmail.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef BCM2835_OTP_H
+#define BCM2835_OTP_H
+
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define TYPE_BCM2835_OTP "bcm2835-otp"
+OBJECT_DECLARE_SIMPLE_TYPE(BCM2835OTPState, BCM2835_OTP)
+
+#define BCM2835_OTP_ROW_COUNT                              66
+
+/* https://elinux.org/BCM2835_registers#OTP */
+#define BCM2835_OTP_BOOTMODE_REG                         0x00
+#define BCM2835_OTP_CONFIG_REG                           0x04
+#define BCM2835_OTP_CTRL_LO_REG                          0x08
+#define BCM2835_OTP_CTRL_HI_REG                          0x0c
+#define BCM2835_OTP_STATUS_REG                           0x10
+#define BCM2835_OTP_BITSEL_REG                           0x14
+#define BCM2835_OTP_DATA_REG                             0x18
+#define BCM2835_OTP_ADDR_REG                             0x1c
+#define BCM2835_OTP_WRITE_DATA_READ_REG                  0x20
+#define BCM2835_OTP_INIT_STATUS_REG                      0x24
+
+
+/* -- Row 32: Undocumented -- */
+
+#define BCM2835_OTP_ROW_32                                 32
+
+/* Lock OTP Programming (Customer OTP and private key) */
+#define BCM2835_OTP_ROW_32_LOCK                        BIT(6)
+
+/* -- Row 36-43: Customer OTP -- */
+
+#define BCM2835_OTP_CUSTOMER_OTP                           36
+#define BCM2835_OTP_CUSTOMER_OTP_LEN                        8
+
+/* Magic numbers to lock programming of customer OTP and private key */
+#define BCM2835_OTP_LOCK_NUM1                      0xffffffff
+#define BCM2835_OTP_LOCK_NUM2                      0xaffe0000
+
+/* -- Row 56-63: Device-specific private key -- */
+
+#define BCM2835_OTP_PRIVATE_KEY                            56
+#define BCM2835_OTP_PRIVATE_KEY_LEN                         8
+
+
+struct BCM2835OTPState {
+    /* <private> */
+    SysBusDevice parent_obj;
+
+    /* <public> */
+    MemoryRegion iomem;
+    uint32_t otp_rows[BCM2835_OTP_ROW_COUNT];
+};
+
+
+uint32_t bcm2835_otp_get_row(BCM2835OTPState *s, unsigned int row);
+void bcm2835_otp_set_row(BCM2835OTPState *s, unsigned int row, uint32_t value);
+
+#endif