GK SDK 源码库: XMIPCLinuxV100R005C00SPC030 (kernel/tools/open_source excluded)

source/trusted-firmware/trusted-firmware-a-2.8/drivers/cfi/v2m/v2m_flash.c

@@ -0,0 +1,196 @@
+/*
+ * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+
+#include <drivers/cfi/v2m_flash.h>
+#include <lib/mmio.h>
+
+/*
+ * This file supplies a low level interface to the vexpress NOR flash
+ * memory of juno and fvp. This memory is organized as an interleaved
+ * memory of two chips with a 16 bit word. It means that every 32 bit
+ * access is going to access to two different chips. This is very
+ * important when we send commands or read status of the chips.
+ */
+
+/*
+ * DWS ready poll retries. The number of retries in this driver have been
+ * obtained empirically from Juno. FVP implements a zero wait state NOR flash
+ * model
+ */
+#define DWS_WORD_PROGRAM_RETRIES	1000
+#define DWS_WORD_ERASE_RETRIES		3000000
+#define DWS_WORD_LOCK_RETRIES		1000
+
+/* Helper macro to detect end of command */
+#define NOR_CMD_END (NOR_DWS | (NOR_DWS << 16l))
+
+/* Helper macros to access two flash banks in parallel */
+#define NOR_2X16(d)			((d << 16) | (d & 0xffff))
+
+static unsigned int nor_status(uintptr_t base_addr)
+{
+	unsigned long status;
+
+	nor_send_cmd(base_addr, NOR_CMD_READ_STATUS_REG);
+	status = mmio_read_32(base_addr);
+	status |= status >> 16; /* merge status from both flash banks */
+
+	return status & 0xFFFF;
+}
+
+/*
+ * Poll Write State Machine.
+ * Return values:
+ *    0      = WSM ready
+ *    -EBUSY = WSM busy after the number of retries
+ */
+static int nor_poll_dws(uintptr_t base_addr, unsigned long int retries)
+{
+	unsigned long status;
+
+	do {
+		nor_send_cmd(base_addr, NOR_CMD_READ_STATUS_REG);
+		status = mmio_read_32(base_addr);
+		if ((status & NOR_CMD_END) == NOR_CMD_END)
+			return 0;
+	} while (retries-- > 0);
+
+	return -EBUSY;
+}
+
+/*
+ * Return values:
+ *    0      = success
+ *    -EPERM = Device protected or Block locked
+ *    -EIO   = General I/O error
+ */
+static int nor_full_status_check(uintptr_t base_addr)
+{
+	unsigned long status;
+
+	/* Full status check */
+	status = nor_status(base_addr);
+
+	if (status & (NOR_PS | NOR_BLS | NOR_ESS | NOR_PSS))
+		return -EPERM;
+	if (status & (NOR_VPPS | NOR_ES))
+		return -EIO;
+	return 0;
+}
+
+void nor_send_cmd(uintptr_t base_addr, unsigned long cmd)
+{
+	mmio_write_32(base_addr, NOR_2X16(cmd));
+}
+
+/*
+ * This function programs a word in the flash. Be aware that it only
+ * can reset bits that were previously set. It cannot set bits that
+ * were previously reset. The resulting bits = old_bits & new bits.
+ * Return values:
+ *  0 = success
+ *  otherwise it returns a negative value
+ */
+int nor_word_program(uintptr_t base_addr, unsigned long data)
+{
+	uint32_t status;
+	int ret;
+
+	nor_send_cmd(base_addr, NOR_CMD_CLEAR_STATUS_REG);
+
+	/* Set the device in write word mode */
+	nor_send_cmd(base_addr, NOR_CMD_WORD_PROGRAM);
+	mmio_write_32(base_addr, data);
+
+	ret = nor_poll_dws(base_addr, DWS_WORD_PROGRAM_RETRIES);
+	if (ret == 0) {
+		/* Full status check */
+		nor_send_cmd(base_addr, NOR_CMD_READ_STATUS_REG);
+		status = mmio_read_32(base_addr);
+
+		if (status & (NOR_PS | NOR_BLS)) {
+			nor_send_cmd(base_addr, NOR_CMD_CLEAR_STATUS_REG);
+			ret = -EPERM;
+		}
+	}
+
+	if (ret == 0)
+		ret = nor_full_status_check(base_addr);
+	nor_send_cmd(base_addr, NOR_CMD_READ_ARRAY);
+
+	return ret;
+}
+
+/*
+ * Erase a full 256K block
+ * Return values:
+ *  0 = success
+ *  otherwise it returns a negative value
+ */
+int nor_erase(uintptr_t base_addr)
+{
+	int ret;
+
+	nor_send_cmd(base_addr, NOR_CMD_CLEAR_STATUS_REG);
+
+	nor_send_cmd(base_addr, NOR_CMD_BLOCK_ERASE);
+	nor_send_cmd(base_addr, NOR_CMD_BLOCK_ERASE_ACK);
+
+	ret = nor_poll_dws(base_addr, DWS_WORD_ERASE_RETRIES);
+	if (ret == 0)
+		ret = nor_full_status_check(base_addr);
+	nor_send_cmd(base_addr, NOR_CMD_READ_ARRAY);
+
+	return ret;
+}
+
+/*
+ * Lock a full 256 block
+ * Return values:
+ *  0 = success
+ *  otherwise it returns a negative value
+ */
+int nor_lock(uintptr_t base_addr)
+{
+	int ret;
+
+	nor_send_cmd(base_addr, NOR_CMD_CLEAR_STATUS_REG);
+
+	nor_send_cmd(base_addr, NOR_CMD_LOCK_UNLOCK);
+	nor_send_cmd(base_addr, NOR_LOCK_BLOCK);
+
+	ret = nor_poll_dws(base_addr, DWS_WORD_LOCK_RETRIES);
+	if (ret == 0)
+		ret = nor_full_status_check(base_addr);
+	nor_send_cmd(base_addr, NOR_CMD_READ_ARRAY);
+
+	return ret;
+}
+
+/*
+ * unlock a full 256 block
+ * Return values:
+ *  0 = success
+ *  otherwise it returns a negative value
+ */
+int nor_unlock(uintptr_t base_addr)
+{
+	int ret;
+
+	nor_send_cmd(base_addr, NOR_CMD_CLEAR_STATUS_REG);
+
+	nor_send_cmd(base_addr, NOR_CMD_LOCK_UNLOCK);
+	nor_send_cmd(base_addr, NOR_UNLOCK_BLOCK);
+
+	ret = nor_poll_dws(base_addr, DWS_WORD_LOCK_RETRIES);
+	if (ret == 0)
+		ret = nor_full_status_check(base_addr);
+	nor_send_cmd(base_addr, NOR_CMD_READ_ARRAY);
+
+	return ret;
+}