[PATCH v3 01/10] misc: add driver for the Sifive otp controller

Pragnesh Patel pragnesh.patel at sifive.com
Fri Jan 24 06:50:14 CET 2020


Added a misc driver to handle OTP memory in FU540.

Signed-off-by: Pragnesh Patel <pragnesh.patel at sifive.com>
Reviewed-by: Anup Patel <anup.patel at wdc.com>
---
 arch/riscv/dts/fu540-c000-u-boot.dtsi         |  13 ++
 .../dts/hifive-unleashed-a00-u-boot.dtsi      |   6 +
 board/sifive/fu540/fu540.c                    | 113 ++++------
 configs/sifive_fu540_defconfig                |   2 +
 drivers/misc/Kconfig                          |   7 +
 drivers/misc/Makefile                         |   1 +
 drivers/misc/ememory-otp.c                    | 207 ++++++++++++++++++
 7 files changed, 276 insertions(+), 73 deletions(-)
 create mode 100644 arch/riscv/dts/fu540-c000-u-boot.dtsi
 create mode 100644 arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
 create mode 100644 drivers/misc/ememory-otp.c

diff --git a/arch/riscv/dts/fu540-c000-u-boot.dtsi b/arch/riscv/dts/fu540-c000-u-boot.dtsi
new file mode 100644
index 0000000000..615a68c0e9
--- /dev/null
+++ b/arch/riscv/dts/fu540-c000-u-boot.dtsi
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2019 SiFive, Inc
+ */
+
+/ {
+	soc {
+		otp: otp at 10070000 {
+			compatible = "sifive,fu540-otp";
+			reg = <0x0 0x10070000 0x0 0x0FFF>;
+		};
+	};
+};
diff --git a/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi b/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
new file mode 100644
index 0000000000..bec0d19134
--- /dev/null
+++ b/arch/riscv/dts/hifive-unleashed-a00-u-boot.dtsi
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 SiFive, Inc
+ */
+
+#include "fu540-c000-u-boot.dtsi"
diff --git a/board/sifive/fu540/fu540.c b/board/sifive/fu540/fu540.c
index 47a2090251..3a5e74f1fb 100644
--- a/board/sifive/fu540/fu540.c
+++ b/board/sifive/fu540/fu540.c
@@ -10,94 +10,61 @@
 #include <dm.h>
 #include <linux/delay.h>
 #include <linux/io.h>
+#include <misc.h>
 
-#ifdef CONFIG_MISC_INIT_R
-
-#define FU540_OTP_BASE_ADDR			0x10070000
-
-struct fu540_otp_regs {
-	u32 pa;     /* Address input */
-	u32 paio;   /* Program address input */
-	u32 pas;    /* Program redundancy cell selection input */
-	u32 pce;    /* OTP Macro enable input */
-	u32 pclk;   /* Clock input */
-	u32 pdin;   /* Write data input */
-	u32 pdout;  /* Read data output */
-	u32 pdstb;  /* Deep standby mode enable input (active low) */
-	u32 pprog;  /* Program mode enable input */
-	u32 ptc;    /* Test column enable input */
-	u32 ptm;    /* Test mode enable input */
-	u32 ptm_rep;/* Repair function test mode enable input */
-	u32 ptr;    /* Test row enable input */
-	u32 ptrim;  /* Repair function enable input */
-	u32 pwe;    /* Write enable input (defines program cycle) */
-} __packed;
-
-#define BYTES_PER_FUSE				4
-#define NUM_FUSES				0x1000
-
-static int fu540_otp_read(int offset, void *buf, int size)
-{
-	struct fu540_otp_regs *regs = (void __iomem *)FU540_OTP_BASE_ADDR;
-	unsigned int i;
-	int fuseidx = offset / BYTES_PER_FUSE;
-	int fusecount = size / BYTES_PER_FUSE;
-	u32 fusebuf[fusecount];
-
-	/* check bounds */
-	if (offset < 0 || size < 0)
-		return -EINVAL;
-	if (fuseidx >= NUM_FUSES)
-		return -EINVAL;
-	if ((fuseidx + fusecount) > NUM_FUSES)
-		return -EINVAL;
-
-	/* init OTP */
-	writel(0x01, &regs->pdstb); /* wake up from stand-by */
-	writel(0x01, &regs->ptrim); /* enable repair function */
-	writel(0x01, &regs->pce);   /* enable input */
-
-	/* read all requested fuses */
-	for (i = 0; i < fusecount; i++, fuseidx++) {
-		writel(fuseidx, &regs->pa);
-
-		/* cycle clock to read */
-		writel(0x01, &regs->pclk);
-		mdelay(1);
-		writel(0x00, &regs->pclk);
-		mdelay(1);
-
-		/* read the value */
-		fusebuf[i] = readl(&regs->pdout);
-	}
-
-	/* shut down */
-	writel(0, &regs->pce);
-	writel(0, &regs->ptrim);
-	writel(0, &regs->pdstb);
-
-	/* copy out */
-	memcpy(buf, fusebuf, size);
+/*
+ * This define is a value used for error/unknown serial.
+ * If we really care about distinguishing errors and 0 is
+ * valid, we'll need a different one.
+ */
+#define ERROR_READING_SERIAL_NUMBER       0
 
-	return 0;
-}
+#ifdef CONFIG_MISC_INIT_R
 
-static u32 fu540_read_serialnum(void)
+#if CONFIG_IS_ENABLED(EMEMORY_OTP)
+static u32 otp_read_serialnum(struct udevice *dev)
 {
 	int ret;
 	u32 serial[2] = {0};
 
 	for (int i = 0xfe * 4; i > 0; i -= 8) {
-		ret = fu540_otp_read(i, serial, sizeof(serial));
+		ret = misc_read(dev, i, serial, sizeof(serial));
+
 		if (ret) {
-			printf("%s: error reading from OTP\n", __func__);
+			printf("%s: error reading serial from OTP\n", __func__);
 			break;
 		}
+
 		if (serial[0] == ~serial[1])
 			return serial[0];
 	}
 
-	return 0;
+	return ERROR_READING_SERIAL_NUMBER;
+}
+#endif
+
+static u32 fu540_read_serialnum(void)
+{
+	u32 serial = ERROR_READING_SERIAL_NUMBER;
+
+#if CONFIG_IS_ENABLED(EMEMORY_OTP)
+	struct udevice *dev;
+	int ret;
+
+	// init OTP
+	ret = uclass_get_device_by_driver(UCLASS_MISC,
+					  DM_GET_DRIVER(hifive_otp), &dev);
+
+	if (ret) {
+		debug("%s: could not find otp device\n", __func__);
+		return serial;
+	}
+
+	// read serial from OTP and set env var
+	serial = otp_read_serialnum(dev);
+#endif
+
+	return serial;
 }
 
 static void fu540_setup_macaddr(u32 serialnum)
diff --git a/configs/sifive_fu540_defconfig b/configs/sifive_fu540_defconfig
index 6d61e6c960..40e78f12a2 100644
--- a/configs/sifive_fu540_defconfig
+++ b/configs/sifive_fu540_defconfig
@@ -6,6 +6,8 @@ CONFIG_ARCH_RV64I=y
 CONFIG_RISCV_SMODE=y
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
+CONFIG_MISC=y
+CONFIG_EMEMORY_OTP=y
 CONFIG_MISC_INIT_R=y
 CONFIG_DISPLAY_CPUINFO=y
 CONFIG_DISPLAY_BOARDINFO=y
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index f18aa8f7ba..cbda0deb14 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -68,6 +68,13 @@ config ROCKCHIP_OTP
 	  addressing and a length or through child-nodes that are generated
 	  based on the e-fuse map retrieved from the DTS.
 
+config EMEMORY_OTP
+       bool "Sifive Ememory OTP driver"
+       depends on RISCV && MISC
+       help
+         Enable support for reading the Ememory OTP on the HiFive Unleashed
+         OTP storage.
+
 config VEXPRESS_CONFIG
 	bool "Enable support for Arm Versatile Express config bus"
 	depends on MISC
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 2b843de93c..dcf9b628c8 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_$(SPL_)PWRSEQ) += pwrseq-uclass.o
 obj-$(CONFIG_QFW) += qfw.o
 obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
 obj-$(CONFIG_ROCKCHIP_OTP) += rockchip-otp.o
+obj-$(CONFIG_EMEMORY_OTP) += ememory-otp.o
 obj-$(CONFIG_SANDBOX) += syscon_sandbox.o misc_sandbox.o
 obj-$(CONFIG_SMSC_LPC47M) += smsc_lpc47m.o
 obj-$(CONFIG_SMSC_SIO1007) += smsc_sio1007.o
diff --git a/drivers/misc/ememory-otp.c b/drivers/misc/ememory-otp.c
new file mode 100644
index 0000000000..73e7af496a
--- /dev/null
+++ b/drivers/misc/ememory-otp.c
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This is a driver for the eMemory EG004K32TQ028XW01 NeoFuse
+ * One-Time-Programmable (OTP) memory used within the SiFive FU540.
+ * It is documented in the FU540 manual here:
+ * https://www.sifive.com/documentation/chips/freedom-u540-c000-manual/
+ *
+ * Copyright (C) 2018 Philipp Hug <philipp at hug.cx>
+ * Copyright (C) 2018 Joey Hewitt <joey at joeyhewitt.com>
+ *
+ * Copyright (C) 2020 SiFive, Inc
+ */
+
+/*
+ * The FU540 stores 4096x32 bit (16KiB) values.
+ * Index 0x00-0xff are reserved for SiFive internal use. (first 1KiB)
+ */
+
+#include <common.h>
+#include <dm/device.h>
+#include <dm/read.h>
+#include <linux/io.h>
+#include <misc.h>
+
+struct hifive_otp_regs {
+	u32 pa;     /* Address input */
+	u32 paio;   /* Program address input */
+	u32 pas;    /* Program redundancy cell selection input */
+	u32 pce;    /* OTP Macro enable input */
+	u32 pclk;   /* Clock input */
+	u32 pdin;   /* Write data input */
+	u32 pdout;  /* Read data output */
+	u32 pdstb;  /* Deep standby mode enable input (active low) */
+	u32 pprog;  /* Program mode enable input */
+	u32 ptc;    /* Test column enable input */
+	u32 ptm;    /* Test mode enable input */
+	u32 ptm_rep;/* Repair function test mode enable input */
+	u32 ptr;    /* Test row enable input */
+	u32 ptrim;  /* Repair function enable input */
+	u32 pwe;    /* Write enable input (defines program cycle) */
+} __packed;
+
+struct hifive_otp_platdata {
+	struct hifive_otp_regs __iomem *regs;
+};
+
+typedef u32 fuse_value_t;
+#define BYTES_PER_FUSE     4
+
+#define NUM_FUSES          0x1000
+
+/*
+ * offset and size are assumed aligned to the size of the fuses (32bit).
+ */
+static int hifive_otp_read(struct udevice *dev, int offset,
+			   void *buf, int size)
+{
+	struct hifive_otp_platdata *plat = dev_get_platdata(dev);
+	struct hifive_otp_regs *regs = (struct hifive_otp_regs *)plat->regs;
+
+	int fuseidx = offset / BYTES_PER_FUSE;
+	int fusecount = size / BYTES_PER_FUSE;
+	fuse_value_t fusebuf[fusecount];
+
+	// check bounds
+	if (offset < 0 || size < 0)
+		return -EINVAL;
+	if (fuseidx >= NUM_FUSES)
+		return -EINVAL;
+	if ((fuseidx + fusecount) > NUM_FUSES)
+		return -EINVAL;
+
+	// init OTP
+	iowrite32(0x01, &regs->pdstb); // wake up from stand-by
+	iowrite32(0x01, &regs->ptrim); // enable repair function
+	iowrite32(0x01, &regs->pce);   // enable input
+
+	// read all requested fuses
+	for (unsigned int i = 0; i < fusecount; i++, fuseidx++) {
+		iowrite32(fuseidx, &regs->pa);
+
+		// cycle clock to read
+		iowrite32(0x01, &regs->pclk);
+		mdelay(1);
+		iowrite32(0x00, &regs->pclk);
+		mdelay(1);
+
+		// read the value
+		fusebuf[i] = ioread32(&regs->pdout);
+	}
+
+	// shut down
+	iowrite32(0, &regs->pce);
+	iowrite32(0, &regs->ptrim);
+	iowrite32(0, &regs->pdstb);
+
+	// copy out
+	memcpy(buf, fusebuf, size);
+
+	return 0;
+}
+
+/*
+ * Caution:
+ * OTP can be write only once, so use carefully.
+ *
+ * offset and size are assumed aligned to the size of the fuses (32bit).
+ */
+static int hifive_otp_write(struct udevice *dev, int offset,
+			    const void *buf, int size)
+{
+	struct hifive_otp_platdata *plat = dev_get_platdata(dev);
+	struct hifive_otp_regs *regs = (struct hifive_otp_regs *)plat->regs;
+
+	int fuseidx = offset / BYTES_PER_FUSE;
+	int fusecount = size / BYTES_PER_FUSE;
+	u32 *write_buf = (u32 *)buf;
+	u32 write_data;
+	int i, pas, bit;
+
+	// check bounds
+	if (offset < 0 || size < 0)
+		return -EINVAL;
+	if (fuseidx >= NUM_FUSES)
+		return -EINVAL;
+	if ((fuseidx + fusecount) > NUM_FUSES)
+		return -EINVAL;
+
+	// init OTP
+	iowrite32(0x01, &regs->pdstb);  // wake up from stand-by
+	iowrite32(0x01, &regs->ptrim);  // enable repair function
+
+	iowrite32(0x00, &regs->pclk);
+	iowrite32(0x00, &regs->pa);
+	iowrite32(0x00, &regs->pas);
+	iowrite32(0x00, &regs->paio);
+	iowrite32(0x00, &regs->pdin);
+	iowrite32(0x00, &regs->pwe);
+	iowrite32(0x02, &regs->ptm);
+	mdelay(1);
+
+	iowrite32(0x01, &regs->pce);    // enable input
+	iowrite32(0x01, &regs->pprog);  // Program mode enable input
+	iowrite32(0x01, &regs->ptrim);
+
+	// write all requested fuses
+	for (i = 0; i < fusecount; i++, fuseidx++) {
+		iowrite32(fuseidx, &regs->pa);
+		write_data = *(write_buf++);
+
+		for (pas = 0; pas < 2; pas++) {
+			iowrite32(pas, &regs->pas);
+
+			for (bit = 0; bit < 32; bit++) {
+				iowrite32(bit, &regs->paio);
+				iowrite32(((write_data >> bit) & 1),
+					  &regs->pdin);
+				mdelay(1);
+
+				iowrite32(0x01, &regs->pwe);
+				mdelay(1);
+				iowrite32(0x00, &regs->pwe);
+				mdelay(1);
+			}
+		}
+
+		iowrite32(0x00, &regs->pas);
+	}
+
+	// shut down
+	iowrite32(0x00, &regs->pwe);
+	iowrite32(0x00, &regs->pprog);
+	iowrite32(0x00, &regs->pce);
+	iowrite32(0x00, &regs->ptm);
+
+	iowrite32(0x00, &regs->ptrim);
+	iowrite32(0x00, &regs->pdstb);
+
+	return 0;
+}
+
+static int hifive_otp_ofdata_to_platdata(struct udevice *dev)
+{
+	struct hifive_otp_platdata *plat = dev_get_platdata(dev);
+
+	plat->regs = dev_read_addr_ptr(dev);
+	return 0;
+}
+
+static const struct misc_ops hifive_otp_ops = {
+	.read = hifive_otp_read,
+	.write = hifive_otp_write,
+};
+
+static const struct udevice_id hifive_otp_ids[] = {
+	{ .compatible = "sifive,fu540-otp" },
+	{}
+};
+
+U_BOOT_DRIVER(hifive_otp) = {
+	.name = "hifive_otp",
+	.id = UCLASS_MISC,
+	.of_match = hifive_otp_ids,
+	.ofdata_to_platdata = hifive_otp_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct hifive_otp_platdata),
+	.ops = &hifive_otp_ops,
+};
-- 
2.17.1



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