stm32mp1: add bsec driver

Add a MISC driver with read and write access to BSEC IP
(Boot and Security and OTP control)
- offset 0: shadowed values
- offset 0x80000000: OTP fuse box values (SAFMEM)

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

arch/arm/mach-stm32mp/Makefile

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+# SPDX-License-Identifier: GPL-2.0+
 #
 # Copyright (C) 2018, STMicroelectronics - All Rights Reserved
 #
@@ -7,6 +7,10 @@ obj-y += cpu.o
 obj-y += dram_init.o
 obj-y += syscon.o
 
-obj-$(CONFIG_SPL_BUILD) += spl.o
+ifdef CONFIG_SPL_BUILD
+obj-y += spl.o
+else
+obj-y += bsec.o
+endif
 obj-$(CONFIG_ARMV7_PSCI) += psci.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR) += pwr_regulator.o

arch/arm/mach-stm32mp/bsec.c

@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <misc.h>
+#include <asm/io.h>
+#include <linux/iopoll.h>
+
+#define BSEC_OTP_MAX_VALUE		95
+
+#define BSEC_TIMEOUT_US			10000
+
+/* BSEC REGISTER OFFSET (base relative) */
+#define BSEC_OTP_CONF_OFF		0x000
+#define BSEC_OTP_CTRL_OFF		0x004
+#define BSEC_OTP_WRDATA_OFF		0x008
+#define BSEC_OTP_STATUS_OFF		0x00C
+#define BSEC_OTP_LOCK_OFF		0x010
+#define BSEC_DISTURBED_OFF		0x01C
+#define BSEC_ERROR_OFF			0x034
+#define BSEC_SPLOCK_OFF			0x064 /* Program safmem sticky lock */
+#define BSEC_SWLOCK_OFF			0x07C /* write in OTP sticky lock */
+#define BSEC_SRLOCK_OFF			0x094 /* shadowing sticky lock */
+#define BSEC_OTP_DATA_OFF		0x200
+
+/* BSEC_CONFIGURATION Register MASK */
+#define BSEC_CONF_POWER_UP		0x001
+
+/* BSEC_CONTROL Register */
+#define BSEC_READ			0x000
+#define BSEC_WRITE			0x100
+
+/* LOCK Register */
+#define OTP_LOCK_MASK			0x1F
+#define OTP_LOCK_BANK_SHIFT		0x05
+#define OTP_LOCK_BIT_MASK		0x01
+
+/* STATUS Register */
+#define BSEC_MODE_BUSY_MASK		0x08
+#define BSEC_MODE_PROGFAIL_MASK		0x10
+#define BSEC_MODE_PWR_MASK		0x20
+
+/*
+ * OTP Lock services definition
+ * Value must corresponding to the bit number in the register
+ */
+#define BSEC_LOCK_PROGRAM		0x04
+
+/**
+ * bsec_check_error() - Check status of one otp
+ * @base: base address of bsec IP
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: 0 if no error, -EAGAIN or -ENOTSUPP
+ */
+static u32 bsec_check_error(u32 base, u32 otp)
+{
+	u32 bit;
+	u32 bank;
+
+	bit = 1 << (otp & OTP_LOCK_MASK);
+	bank = ((otp >> OTP_LOCK_BANK_SHIFT) & OTP_LOCK_MASK) * sizeof(u32);
+
+	if (readl(base + BSEC_DISTURBED_OFF + bank) & bit)
+		return -EAGAIN;
+	else if (readl(base + BSEC_ERROR_OFF + bank) & bit)
+		return -ENOTSUPP;
+
+	return 0;
+}
+
+/**
+ * bsec_lock() - manage lock for each type SR/SP/SW
+ * @address: address of bsec IP register
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: true if locked else false
+ */
+static bool bsec_read_lock(u32 address, u32 otp)
+{
+	u32 bit;
+	u32 bank;
+
+	bit = 1 << (otp & OTP_LOCK_MASK);
+	bank = ((otp >> OTP_LOCK_BANK_SHIFT) & OTP_LOCK_MASK) * sizeof(u32);
+
+	return !!(readl(address + bank) & bit);
+}
+
+/**
+ * bsec_read_SR_lock() - read SR lock (Shadowing)
+ * @base: base address of bsec IP
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: true if locked else false
+ */
+static bool bsec_read_SR_lock(u32 base, u32 otp)
+{
+	return bsec_read_lock(base + BSEC_SRLOCK_OFF, otp);
+}
+
+/**
+ * bsec_read_SP_lock() - read SP lock (program Lock)
+ * @base: base address of bsec IP
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: true if locked else false
+ */
+static bool bsec_read_SP_lock(u32 base, u32 otp)
+{
+	return bsec_read_lock(base + BSEC_SPLOCK_OFF, otp);
+}
+
+/**
+ * bsec_SW_lock() - manage SW lock (Write in Shadow)
+ * @base: base address of bsec IP
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: true if locked else false
+ */
+static bool bsec_read_SW_lock(u32 base, u32 otp)
+{
+	return bsec_read_lock(base + BSEC_SWLOCK_OFF, otp);
+}
+
+/**
+ * bsec_power_safmem() - Activate or deactivate safmem power
+ * @base: base address of bsec IP
+ * @power: true to power up , false to power down
+ * Return: 0 if succeed
+ */
+static int bsec_power_safmem(u32 base, bool power)
+{
+	u32 val;
+	u32 mask;
+
+	if (power) {
+		setbits_le32(base + BSEC_OTP_CONF_OFF, BSEC_CONF_POWER_UP);
+		mask = BSEC_MODE_PWR_MASK;
+	} else {
+		clrbits_le32(base + BSEC_OTP_CONF_OFF, BSEC_CONF_POWER_UP);
+		mask = 0;
+	}
+
+	/* waiting loop */
+	return readl_poll_timeout(base + BSEC_OTP_STATUS_OFF,
+				  val, (val & BSEC_MODE_PWR_MASK) == mask,
+				  BSEC_TIMEOUT_US);
+}
+
+/**
+ * bsec_shadow_register() - copy safmen otp to bsec data
+ * @base: base address of bsec IP
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: 0 if no error
+ */
+static int bsec_shadow_register(u32 base, u32 otp)
+{
+	u32 val;
+	int ret;
+	bool power_up = false;
+
+	/* check if shadowing of otp is locked */
+	if (bsec_read_SR_lock(base, otp))
+		pr_debug("bsec : OTP %d is locked and refreshed with 0\n", otp);
+
+	/* check if safemem is power up */
+	val = readl(base + BSEC_OTP_STATUS_OFF);
+	if (!(val & BSEC_MODE_PWR_MASK)) {
+		ret = bsec_power_safmem(base, true);
+		if (ret)
+			return ret;
+		power_up = 1;
+	}
+	/* set BSEC_OTP_CTRL_OFF with the otp value*/
+	writel(otp | BSEC_READ, base + BSEC_OTP_CTRL_OFF);
+
+	/* check otp status*/
+	ret = readl_poll_timeout(base + BSEC_OTP_STATUS_OFF,
+				 val, (val & BSEC_MODE_BUSY_MASK) == 0,
+				 BSEC_TIMEOUT_US);
+	if (ret)
+		return ret;
+
+	ret = bsec_check_error(base, otp);
+
+	if (power_up)
+		bsec_power_safmem(base, false);
+
+	return ret;
+}
+
+/**
+ * bsec_read_shadow() - read an otp data value from shadow
+ * @base: base address of bsec IP
+ * @val: read value
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: 0 if no error
+ */
+static int bsec_read_shadow(u32 base, u32 *val, u32 otp)
+{
+	*val = readl(base + BSEC_OTP_DATA_OFF + otp * sizeof(u32));
+
+	return bsec_check_error(base, otp);
+}
+
+/**
+ * bsec_write_shadow() - write value in BSEC data register in shadow
+ * @base: base address of bsec IP
+ * @val: value to write
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * Return: 0 if no error
+ */
+static int bsec_write_shadow(u32 base, u32 val, u32 otp)
+{
+	/* check if programming of otp is locked */
+	if (bsec_read_SW_lock(base, otp))
+		pr_debug("bsec : OTP %d is lock, write will be ignore\n", otp);
+
+	writel(val, base + BSEC_OTP_DATA_OFF + otp * sizeof(u32));
+
+	return bsec_check_error(base, otp);
+}
+
+/**
+ * bsec_program_otp() - program a bit in SAFMEM
+ * @base: base address of bsec IP
+ * @val: value to program
+ * @otp: otp number (0 - BSEC_OTP_MAX_VALUE)
+ * after the function the otp data is not refreshed in shadow
+ * Return: 0 if no error
+ */
+static int bsec_program_otp(long base, u32 val, u32 otp)
+{
+	u32 ret;
+	bool power_up = false;
+
+	if (bsec_read_SP_lock(base, otp))
+		pr_debug("bsec : OTP %d locked, prog will be ignore\n", otp);
+
+	if (readl(base + BSEC_OTP_LOCK_OFF) & (1 << BSEC_LOCK_PROGRAM))
+		pr_debug("bsec : Global lock, prog will be ignore\n");
+
+	/* check if safemem is power up */
+	if (!(readl(base + BSEC_OTP_STATUS_OFF) & BSEC_MODE_PWR_MASK)) {
+		ret = bsec_power_safmem(base, true);
+		if (ret)
+			return ret;
+
+		power_up = true;
+	}
+	/* set value in write register*/
+	writel(val, base + BSEC_OTP_WRDATA_OFF);
+
+	/* set BSEC_OTP_CTRL_OFF with the otp value */
+	writel(otp | BSEC_WRITE, base + BSEC_OTP_CTRL_OFF);
+
+	/* check otp status*/
+	ret = readl_poll_timeout(base + BSEC_OTP_STATUS_OFF,
+				 val, (val & BSEC_MODE_BUSY_MASK) == 0,
+				 BSEC_TIMEOUT_US);
+	if (ret)
+		return ret;
+
+	if (val & BSEC_MODE_PROGFAIL_MASK)
+		ret = -EACCES;
+	else
+		ret = bsec_check_error(base, otp);
+
+	if (power_up)
+		bsec_power_safmem(base, false);
+
+	return ret;
+}
+
+/* BSEC MISC driver *******************************************************/
+struct stm32mp_bsec_platdata {
+	u32 base;
+};
+
+static int stm32mp_bsec_read_otp(struct udevice *dev, u32 *val, u32 otp)
+{
+	struct stm32mp_bsec_platdata *plat = dev_get_platdata(dev);
+	u32 tmp_data = 0;
+	int ret;
+
+	/* read current shadow value */
+	ret = bsec_read_shadow(plat->base, &tmp_data, otp);
+	if (ret)
+		return ret;
+
+	/* copy otp in shadow */
+	ret = bsec_shadow_register(plat->base, otp);
+	if (ret)
+		return ret;
+
+	ret = bsec_read_shadow(plat->base, val, otp);
+	if (ret)
+		return ret;
+
+	/* restore shadow value */
+	ret = bsec_write_shadow(plat->base, tmp_data, otp);
+	return ret;
+}
+
+static int stm32mp_bsec_read_shadow(struct udevice *dev, u32 *val, u32 otp)
+{
+	struct stm32mp_bsec_platdata *plat = dev_get_platdata(dev);
+
+	return bsec_read_shadow(plat->base, val, otp);
+}
+
+static int stm32mp_bsec_write_otp(struct udevice *dev, u32 val, u32 otp)
+{
+	struct stm32mp_bsec_platdata *plat = dev_get_platdata(dev);
+
+	return bsec_program_otp(plat->base, val, otp);
+}
+
+static int stm32mp_bsec_write_shadow(struct udevice *dev, u32 val, u32 otp)
+{
+	struct stm32mp_bsec_platdata *plat = dev_get_platdata(dev);
+
+	return bsec_write_shadow(plat->base, val, otp);
+}
+
+static int stm32mp_bsec_read(struct udevice *dev, int offset,
+			     void *buf, int size)
+{
+	int ret;
+	int i;
+	bool shadow = true;
+	int nb_otp = size / sizeof(u32);
+	int otp;
+
+	if (offset >= STM32_BSEC_OTP_OFFSET) {
+		offset -= STM32_BSEC_OTP_OFFSET;
+		shadow = false;
+	}
+	otp = offset / sizeof(u32);
+
+	if (otp < 0 || (otp + nb_otp - 1) > BSEC_OTP_MAX_VALUE) {
+		dev_err(dev, "wrong value for otp, max value : %i\n",
+			BSEC_OTP_MAX_VALUE);
+		return -EINVAL;
+	}
+
+	for (i = otp; i < (otp + nb_otp); i++) {
+		u32 *addr = &((u32 *)buf)[i - otp];
+
+		if (shadow)
+			ret = stm32mp_bsec_read_shadow(dev, addr, i);
+		else
+			ret = stm32mp_bsec_read_otp(dev, addr, i);
+
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
+static int stm32mp_bsec_write(struct udevice *dev, int offset,
+			      const void *buf, int size)
+{
+	int ret = 0;
+	int i;
+	bool shadow = true;
+	int nb_otp = size / sizeof(u32);
+	int otp;
+
+	if (offset >= STM32_BSEC_OTP_OFFSET) {
+		offset -= STM32_BSEC_OTP_OFFSET;
+		shadow = false;
+	}
+	otp = offset / sizeof(u32);
+
+	if (otp < 0 || (otp + nb_otp - 1) > BSEC_OTP_MAX_VALUE) {
+		dev_err(dev, "wrong value for otp, max value : %d\n",
+			BSEC_OTP_MAX_VALUE);
+		return -EINVAL;
+	}
+
+	for (i = otp; i < otp + nb_otp; i++) {
+		u32 *val = &((u32 *)buf)[i - otp];
+
+		if (shadow)
+			ret = stm32mp_bsec_write_shadow(dev, *val, i);
+		else
+			ret = stm32mp_bsec_write_otp(dev, *val, i);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
+static const struct misc_ops stm32mp_bsec_ops = {
+	.read = stm32mp_bsec_read,
+	.write = stm32mp_bsec_write,
+};
+
+static int stm32mp_bsec_ofdata_to_platdata(struct udevice *dev)
+{
+	struct stm32mp_bsec_platdata *plat = dev_get_platdata(dev);
+
+	plat->base = (u32)dev_read_addr_ptr(dev);
+
+	return 0;
+}
+
+static const struct udevice_id stm32mp_bsec_ids[] = {
+	{ .compatible = "st,stm32mp-bsec" },
+	{}
+};
+
+U_BOOT_DRIVER(stm32mp_bsec) = {
+	.name = "stm32mp_bsec",
+	.id = UCLASS_MISC,
+	.of_match = stm32mp_bsec_ids,
+	.ofdata_to_platdata = stm32mp_bsec_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct stm32mp_bsec_platdata),
+	.ops = &stm32mp_bsec_ops,
+	.flags  = DM_FLAG_PRE_RELOC,
+};
+
+/* bsec IP is not present in device tee, manage IP address by platdata */
+static struct stm32mp_bsec_platdata stm32_bsec_platdata = {
+	.base = STM32_BSEC_BASE,
+};
+
+U_BOOT_DEVICE(stm32mp_bsec) = {
+	.name = "stm32mp_bsec",
+	.platdata = &stm32_bsec_platdata,
+};

arch/arm/mach-stm32mp/include/mach/stm32.h

@@ -13,6 +13,7 @@
 #define STM32_RCC_BASE			0x50000000
 #define STM32_PWR_BASE			0x50001000
 #define STM32_DBGMCU_BASE		0x50081000
+#define STM32_BSEC_BASE			0x5C005000
 #define STM32_TZC_BASE			0x5C006000
 #define STM32_ETZPC_BASE		0x5C007000
 #define STM32_TAMP_BASE			0x5C00A000
@@ -95,5 +96,9 @@ enum boot_device {
 #define TAMP_BOOT_DEVICE_MASK		GENMASK(7, 4)
 #define TAMP_BOOT_INSTANCE_MASK		GENMASK(3, 0)
 
+/* offset used for BSEC driver: misc_read and misc_write */
+#define STM32_BSEC_SHADOW_OFFSET	0x0
+#define STM32_BSEC_OTP_OFFSET		0x80000000
+
 #endif /* __ASSEMBLY__*/
 #endif /* _MACH_STM32_H_ */