stm32mp1: add FUSE command support

Add support of fuse command (read/write/program/sense)
on bank 0 to access to BSEC SAFMEM (4096 OTP bits).

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

MAINTAINERS

@@ -204,6 +204,7 @@ M:	Patrick Delaunay <patrick.delaunay@st.com>
 S:	Maintained
 F:	arch/arm/mach-stm32mp
 F:	drivers/clk/clk_stm32mp1.c
+F:	drivers/misc/stm32mp_fuse.c
 F:	drivers/ram/stm32mp1/
 
 ARM STM STV0991

arch/arm/Kconfig

@@ -1225,6 +1225,7 @@ config ARCH_STM32MP
 	select DM_SERIAL
 	select OF_CONTROL
 	select OF_LIBFDT
+	select MISC
 	select PINCTRL
 	select REGMAP
 	select SUPPORT_SPL

configs/stm32mp15_basic_defconfig

@@ -18,6 +18,7 @@ CONFIG_SYS_PROMPT="STM32MP> "
 # CONFIG_CMD_EXPORTENV is not set
 # CONFIG_CMD_IMPORTENV is not set
 CONFIG_CMD_MEMINFO=y
+CONFIG_CMD_FUSE=y
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_GPT=y
 CONFIG_CMD_I2C=y

drivers/misc/Kconfig

@@ -158,6 +158,15 @@ config PCA9551_I2C_ADDR
 	help
 	  The I2C address of the PCA9551 LED controller.
 
+config STM32MP_FUSE
+	bool "Enable STM32MP fuse wrapper providing the fuse API"
+	depends on ARCH_STM32MP && MISC
+	default y if CMD_FUSE
+	help
+	  If you say Y here, you will get support for the fuse API (OTP)
+	  for STM32MP architecture.
+	  This API is needed for CMD_FUSE.
+
 config STM32_RCC
 	bool "Enable RCC driver for the STM32 SoC's family"
 	depends on STM32 && MISC

drivers/misc/Makefile

@@ -51,5 +51,6 @@ obj-$(CONFIG_WINBOND_W83627) += winbond_w83627.o
 obj-$(CONFIG_QFW) += qfw.o
 obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
 obj-$(CONFIG_STM32_RCC) += stm32_rcc.o
+obj-$(CONFIG_STM32MP_FUSE) += stm32mp_fuse.o
 obj-$(CONFIG_SYS_DPAA_QBMAN) += fsl_portals.o
 obj-$(CONFIG_GDSYS_RXAUI_CTRL) += gdsys_rxaui_ctrl.o

drivers/misc/stm32mp_fuse.c

@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <command.h>
+#include <misc.h>
+#include <errno.h>
+#include <dm/device.h>
+#include <dm/uclass.h>
+
+#define STM32MP_OTP_BANK	0
+
+/*
+ * The 'fuse' command API
+ */
+int fuse_read(u32 bank, u32 word, u32 *val)
+{
+	int ret = 0;
+	struct udevice *dev;
+
+	switch (bank) {
+	case STM32MP_OTP_BANK:
+		ret = uclass_get_device_by_driver(UCLASS_MISC,
+						  DM_GET_DRIVER(stm32mp_bsec),
+						  &dev);
+		if (ret)
+			return ret;
+		ret = misc_read(dev, word * 4 + STM32_BSEC_SHADOW_OFFSET,
+				val, 4);
+		break;
+
+	default:
+		printf("stm32mp %s: wrong value for bank %i\n", __func__, bank);
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+int fuse_prog(u32 bank, u32 word, u32 val)
+{
+	struct udevice *dev;
+	int ret;
+
+	switch (bank) {
+	case STM32MP_OTP_BANK:
+		ret = uclass_get_device_by_driver(UCLASS_MISC,
+						  DM_GET_DRIVER(stm32mp_bsec),
+						  &dev);
+		if (ret)
+			return ret;
+		ret = misc_write(dev, word * 4 + STM32_BSEC_OTP_OFFSET,
+				 &val, 4);
+		break;
+
+	default:
+		printf("stm32mp %s: wrong value for bank %i\n", __func__, bank);
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+int fuse_sense(u32 bank, u32 word, u32 *val)
+{
+	struct udevice *dev;
+	int ret;
+
+	switch (bank) {
+	case STM32MP_OTP_BANK:
+		ret = uclass_get_device_by_driver(UCLASS_MISC,
+						  DM_GET_DRIVER(stm32mp_bsec),
+						  &dev);
+		if (ret)
+			return ret;
+		ret = misc_read(dev, word * 4 + STM32_BSEC_OTP_OFFSET, val, 4);
+		break;
+
+	default:
+		printf("stm32mp %s: wrong value for bank %i\n", __func__, bank);
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+int fuse_override(u32 bank, u32 word, u32 val)
+{
+	struct udevice *dev;
+	int ret;
+
+	switch (bank) {
+	case STM32MP_OTP_BANK:
+		ret = uclass_get_device_by_driver(UCLASS_MISC,
+						  DM_GET_DRIVER(stm32mp_bsec),
+						  &dev);
+		if (ret)
+			return ret;
+		ret = misc_write(dev, word * 4 + STM32_BSEC_SHADOW_OFFSET,
+				 &val, 4);
+		break;
+
+	default:
+		printf("stm32mp %s: wrong value for bank %i\n",
+		       __func__, bank);
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}