misc: nuvoton: Add NPCM7xx otp controller driver

Add Nuvoton BMC npcm750 otp driver

Signed-off-by: Jim Liu <JJLIU0@nuvoton.com>
diff --git a/drivers/misc/npcm_otp.c b/drivers/misc/npcm_otp.c
new file mode 100644
index 0000000..3049108
--- /dev/null
+++ b/drivers/misc/npcm_otp.c
@@ -0,0 +1,512 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Nuvoton Technology Corp.
+ */
+
+#include <clk.h>
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fuse.h>
+#include <asm/io.h>
+#include <linux/delay.h>
+#include <asm/arch/otp.h>
+
+struct npcm_otp_priv {
+	struct npcm_otp_regs *regs[2];
+};
+
+static struct npcm_otp_priv *otp_priv;
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_check_inputs                                     */
+/*                                                                            */
+/* Parameters:      arr - fuse array number to check                          */
+/*                  word - fuse word (offset) to check                        */
+/* Returns:         int                                                       */
+/* Side effects:                                                              */
+/* Description:     Checks is arr and word are illegal and do not exceed      */
+/*                  their range. Return 0 if they are legal, -1 if not        */
+/*----------------------------------------------------------------------------*/
+static int npcm_otp_check_inputs(u32 arr, u32 word)
+{
+	if (arr >= NPCM_NUM_OF_SA) {
+		if (IS_ENABLED(CONFIG_ARCH_NPCM8XX))
+			printf("\nError: npcm8XX otp includs only one bank: 0\n");
+		if (IS_ENABLED(CONFIG_ARCH_NPCM7XX))
+			printf("\nError: npcm7XX otp includs only two banks: 0 and 1\n");
+		return -1;
+	}
+
+	if (word >= NPCM_OTP_ARR_BYTE_SIZE) {
+		printf("\nError: npcm otp array comprises only %d bytes, numbered from 0 to %d\n",
+		       NPCM_OTP_ARR_BYTE_SIZE, NPCM_OTP_ARR_BYTE_SIZE - 1);
+		return -1;
+	}
+
+	return 0;
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_wait_for_otp_ready                               */
+/*                                                                            */
+/* Parameters:      array - fuse array to wait for                            */
+/* Returns:         int                                                       */
+/* Side effects:                                                              */
+/* Description:     Initialize the Fuse HW module.                            */
+/*----------------------------------------------------------------------------*/
+static int npcm_otp_wait_for_otp_ready(u32 arr, u32 timeout)
+{
+	struct npcm_otp_regs *regs = otp_priv->regs[arr];
+	u32 time = timeout;
+
+	/*------------------------------------------------------------------------*/
+	/* check parameters validity                                              */
+	/*------------------------------------------------------------------------*/
+	if (arr > NPCM_FUSE_SA)
+		return -EINVAL;
+
+	while (--time > 1) {
+		if (readl(&regs->fst) & FST_RDY) {
+			/* fuse is ready, clear the status. */
+			writel(readl(&regs->fst) | FST_RDST, &regs->fst);
+			return 0;
+		}
+	}
+
+	/* try to clear the status in case it was set */
+	writel(readl(&regs->fst) | FST_RDST, &regs->fst);
+
+	return -EINVAL;
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_read_byte                                        */
+/*                                                                            */
+/* Parameters:      arr  - Storage Array type [input].                        */
+/*                  addr - Byte-address to read from [input].                 */
+/*                  data - Pointer to result [output].                        */
+/* Returns:         none                                                      */
+/* Side effects:                                                              */
+/* Description:     Read 8-bit data from an OTP storage array.                */
+/*----------------------------------------------------------------------------*/
+static void npcm_otp_read_byte(u32 arr, u32 addr, u8 *data)
+{
+	struct npcm_otp_regs *regs = otp_priv->regs[arr];
+
+	/* Wait for the Fuse Box Idle */
+	npcm_otp_wait_for_otp_ready(arr, 0xDEADBEEF);
+
+	/* Configure the byte address in the fuse array for read operation */
+	writel(FADDR_VAL(addr, 0), &regs->faddr);
+
+	/* Initiate a read cycle */
+	writel(READ_INIT, &regs->fctl);
+
+	/* Wait for read operation completion */
+	npcm_otp_wait_for_otp_ready(arr, 0xDEADBEEF);
+
+	/* Read the result */
+	*data = readl(&regs->fdata) & FDATA_MASK;
+
+	/* Clean FDATA contents to prevent unauthorized software from reading
+	 * sensitive information
+	 */
+	writel(FDATA_CLEAN_VALUE, &regs->fdata);
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_bit_is_programmed                                */
+/*                                                                            */
+/* Parameters:      arr     - Storage Array type [input].                     */
+/*                  byte_offset - Byte offset in array [input].               */
+/*                  bit_offset  - Bit offset in byte [input].                 */
+/* Returns:         Nonzero if bit is programmed, zero otherwise.             */
+/* Side effects:                                                              */
+/* Description:     Check if a bit is programmed in an OTP storage array.     */
+/*----------------------------------------------------------------------------*/
+static bool npcm_otp_bit_is_programmed(u32  arr,
+				       u32 byte_offset, u8 bit_offset)
+{
+	u32 data = 0;
+
+	/* Read the entire byte you wish to program */
+	npcm_otp_read_byte(arr, byte_offset, (u8 *)&data);
+
+	/* Check whether the bit is already programmed */
+	if (data & (1 << bit_offset))
+		return true;
+
+	return false;
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_program_bit                                      */
+/*                                                                            */
+/* Parameters:      arr     - Storage Array type [input].                     */
+/*                  byte)offset - Byte offset in array [input].               */
+/*                  bit_offset  - Bit offset in byte [input].                 */
+/* Returns:         int                                                       */
+/* Side effects:                                                              */
+/* Description:     Program (set to 1) a bit in an OTP storage array.         */
+/*----------------------------------------------------------------------------*/
+static int npcm_otp_program_bit(u32 arr, u32 byte_offset,
+				u8 bit_offset)
+{
+	struct npcm_otp_regs *regs = otp_priv->regs[arr];
+	int count;
+	u8 read_data;
+
+	/* Wait for the Fuse Box Idle */
+	npcm_otp_wait_for_otp_ready(arr, 0xDEADBEEF);
+
+	/* Make sure the bit is not already programmed */
+	if (npcm_otp_bit_is_programmed(arr, byte_offset, bit_offset))
+		return 0;
+
+	/* Configure the bit address in the fuse array for program operation */
+	writel(FADDR_VAL(byte_offset, bit_offset), &regs->faddr);
+	writel(readl(&regs->faddr) | FADDR_IN_PROG, &regs->faddr);
+
+	// program up to MAX_PROGRAM_PULSES
+	for (count = 1; count <= MAX_PROGRAM_PULSES; count++) {
+		/* Initiate a program cycle */
+		writel(PROGRAM_ARM, &regs->fctl);
+		writel(PROGRAM_INIT, &regs->fctl);
+
+		/* Wait for program operation completion */
+		npcm_otp_wait_for_otp_ready(arr, 0xDEADBEEF);
+
+		// after MIN_PROGRAM_PULSES start verifying the result
+		if (count >= MIN_PROGRAM_PULSES) {
+			/* Initiate a read cycle */
+			writel(READ_INIT, &regs->fctl);
+
+			/* Wait for read operation completion */
+			npcm_otp_wait_for_otp_ready(arr, 0xDEADBEEF);
+
+			/* Read the result */
+			read_data = readl(&regs->fdata) & FDATA_MASK;
+
+			/* If the bit is set the sequence ended correctly */
+			if (read_data & (1 << bit_offset))
+				break;
+		}
+	}
+
+	// check if programmking failed
+	if (count > MAX_PROGRAM_PULSES) {
+		printf("program fail\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Clean FDATA contents to prevent unauthorized software from reading
+	 * sensitive information
+	 */
+	writel(FDATA_CLEAN_VALUE, &regs->fdata);
+
+	return 0;
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_program_byte                                     */
+/*                                                                            */
+/* Parameters:      arr     - Storage Array type [input].                     */
+/*                  byte_offset - Byte offset in array [input].               */
+/*                  value   - Byte to program [input].                        */
+/* Returns:         int                                                       */
+/* Side effects:                                                              */
+/* Description:     Program (set to 1) a given byte's relevant bits in an     */
+/*                  OTP storage array.                                        */
+/*----------------------------------------------------------------------------*/
+static int npcm_otp_program_byte(u32 arr, u32 byte_offset,
+				 u8 value)
+{
+	int status = 0;
+	unsigned int i;
+	u8 data = 0;
+	int rc;
+
+	rc = npcm_otp_check_inputs(arr, byte_offset);
+	if (rc != 0)
+		return rc;
+
+	/* Wait for the Fuse Box Idle */
+	npcm_otp_wait_for_otp_ready(arr, 0xDEADBEEF);
+
+	/* Read the entire byte you wish to program */
+	npcm_otp_read_byte(arr, byte_offset, &data);
+
+	/* In case all relevant bits are already programmed - nothing to do */
+	if ((~data & value) == 0)
+		return status;
+
+	/* Program unprogrammed bits. */
+	for (i = 0; i < 8; i++) {
+		if (value & (1 << i)) {
+			/* Program (set to 1) the relevant bit */
+			int last_status = npcm_otp_program_bit(arr, byte_offset, (u8)i);
+
+			if (last_status != 0)
+				status = last_status;
+		}
+	}
+	return status;
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_is_fuse_array_disabled                           */
+/*                                                                            */
+/* Parameters:      arr - Storage Array type [input].                         */
+/* Returns:         bool                                                      */
+/* Side effects:                                                              */
+/* Description:     Return true if access to the first 2048 bits of the       */
+/*                  specified fuse array is disabled, false if not            */
+/*----------------------------------------------------------------------------*/
+bool npcm_otp_is_fuse_array_disabled(u32 arr)
+{
+	struct npcm_otp_regs *regs = otp_priv->regs[arr];
+
+	return (readl(&regs->fcfg) & FCFG_FDIS) != 0;
+}
+
+int npcm_otp_select_key(u8 key_index)
+{
+	struct npcm_otp_regs *regs = otp_priv->regs[NPCM_KEY_SA];
+	u32 idx = 0;
+	u32 time = 0xDAEDBEEF;
+
+	if (key_index >= 4)
+		return -1;
+
+	/* Do not destroy ECCDIS bit */
+	idx = readl(&regs->fustrap_fkeyind);
+
+	/* Configure the key size */
+	idx &= ~FKEYIND_KSIZE_MASK;
+	idx |= FKEYIND_KSIZE_256;
+
+	/* Configure the key index (0 to 3) */
+	idx &= ~FKEYIND_KIND_MASK;
+	idx |= FKEYIND_KIND_KEY(key_index);
+
+	writel(idx, &regs->fustrap_fkeyind);
+
+	/* Wait for selection completetion */
+	while (--time > 1) {
+		if (readl(&regs->fustrap_fkeyind) & FKEYIND_KVAL)
+			return 0;
+		udelay(1);
+	}
+
+	return -1;
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_nibble_parity_ecc_encode                         */
+/*                                                                            */
+/* Parameters:      datain - pointer to decoded data buffer                   */
+/*                  dataout - pointer to encoded data buffer (buffer size     */
+/*                            should be 2 x dataout)                          */
+/*                  size - size of encoded data (decoded data x 2)            */
+/* Returns:         none                                                      */
+/* Side effects:                                                              */
+/* Description:     Decodes the data according to nibble parity ECC scheme.   */
+/*                  Size specifies the encoded data size.                     */
+/*                  Decodes whole bytes only                                  */
+/*----------------------------------------------------------------------------*/
+void npcm_otp_nibble_parity_ecc_encode(u8 *datain, u8 *dataout, u32 size)
+{
+	u32 i, idx;
+	u8 E0, E1, E2, E3;
+
+	for (i = 0; i < (size / 2); i++) {
+		E0 = (datain[i] >> 0) & 0x01;
+		E1 = (datain[i] >> 1) & 0x01;
+		E2 = (datain[i] >> 2) & 0x01;
+		E3 = (datain[i] >> 3) & 0x01;
+
+		idx = i * 2;
+		dataout[idx] = datain[i] & 0x0f;
+		dataout[idx] |= (E0 ^ E1) << 4;
+		dataout[idx] |= (E2 ^ E3) << 5;
+		dataout[idx] |= (E0 ^ E2) << 6;
+		dataout[idx] |= (E1 ^ E3) << 7;
+
+		E0 = (datain[i] >> 4) & 0x01;
+		E1 = (datain[i] >> 5) & 0x01;
+		E2 = (datain[i] >> 6) & 0x01;
+		E3 = (datain[i] >> 7) & 0x01;
+
+		idx = i * 2 + 1;
+		dataout[idx] = (datain[i] & 0xf0) >> 4;
+		dataout[idx] |= (E0 ^ E1) << 4;
+		dataout[idx] |= (E2 ^ E3) << 5;
+		dataout[idx] |= (E0 ^ E2) << 6;
+		dataout[idx] |= (E1 ^ E3) << 7;
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        npcm_otp_majority_rule_ecc_encode                         */
+/*                                                                            */
+/* Parameters:      datain - pointer to decoded data buffer                   */
+/*                  dataout - pointer to encoded data buffer (buffer size     */
+/*                            should be 3 x dataout)                          */
+/*                  size - size of encoded data (decoded data x 3)            */
+/* Returns:         none                                                      */
+/* Side effects:                                                              */
+/* Description:     Decodes the data according to Major Rule ECC scheme.      */
+/*                  Size specifies the encoded data size.                     */
+/*                  Decodes whole bytes only                                  */
+/*----------------------------------------------------------------------------*/
+void npcm_otp_majority_rule_ecc_encode(u8 *datain, u8 *dataout, u32 size)
+{
+	u32 byte;
+	u32 bit;
+	u8 bit_val;
+	u32 decoded_size = size / 3;
+
+	for (byte = 0; byte < decoded_size; byte++) {
+		for (bit = 0; bit < 8; bit++) {
+			bit_val = (datain[byte] >> bit) & 0x01;
+
+			if (bit_val) {
+				dataout[byte] |= (1 << bit);
+				dataout[decoded_size + byte] |= (1 << bit);
+				dataout[decoded_size * 2 + byte] |= (1 << bit);
+			} else {
+				dataout[byte] &= ~(1 << bit);
+				dataout[decoded_size + byte] &= ~(1 << bit);
+				dataout[decoded_size * 2 + byte] &= ~(1 << bit);
+			}
+		}
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+/* Function:        fuse_program_data                                         */
+/*                                                                            */
+/* Parameters:      bank - Storage Array type [input].                        */
+/*                  word - Byte offset in array [input].                      */
+/*                  data - Pointer to data buffer to program.                 */
+/*                  size - Number of bytes to program.                        */
+/* Returns:         none                                                      */
+/* Side effects:                                                              */
+/* Description:     Programs the given byte array (size bytes) to the given   */
+/*                  OTP storage array, starting from offset word.             */
+/*----------------------------------------------------------------------------*/
+int fuse_program_data(u32 bank, u32 word, u8 *data, u32 size)
+{
+	u32 arr = (u32)bank;
+	u32 byte;
+	int rc;
+
+	rc = npcm_otp_check_inputs(bank, word + size - 1);
+	if (rc != 0)
+		return rc;
+
+	for (byte = 0; byte < size; byte++) {
+		u8 val;
+
+		val = data[byte];
+		if (val == 0) // optimization
+			continue;
+
+		rc = npcm_otp_program_byte(arr, word + byte, data[byte]);
+		if (rc != 0)
+			return rc;
+
+		// verify programming of every '1' bit
+		val = 0;
+		npcm_otp_read_byte((u32)bank, byte, &val);
+		if ((data[byte] & ~val) != 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+int fuse_prog_image(u32 bank, uintptr_t address)
+{
+	return fuse_program_data(bank, 0, (u8 *)address, NPCM_OTP_ARR_BYTE_SIZE);
+}
+
+int fuse_read(u32 bank, u32 word, u32 *val)
+{
+	int rc = npcm_otp_check_inputs(bank, word);
+
+	if (rc != 0)
+		return rc;
+
+	*val = 0;
+	npcm_otp_read_byte((u32)bank, word, (u8 *)val);
+
+	return 0;
+}
+
+int fuse_sense(u32 bank, u32 word, u32 *val)
+{
+	/* We do not support overriding */
+	return -EINVAL;
+}
+
+int fuse_prog(u32 bank, u32 word, u32 val)
+{
+	int rc;
+
+	rc = npcm_otp_check_inputs(bank, word);
+	if (rc != 0)
+		return rc;
+
+	return npcm_otp_program_byte(bank, word, (u8)val);
+}
+
+int fuse_override(u32 bank, u32 word, u32 val)
+{
+	/* We do not support overriding */
+	return -EINVAL;
+}
+
+static int npcm_otp_bind(struct udevice *dev)
+{
+	struct npcm_otp_regs *regs;
+
+	otp_priv = calloc(1, sizeof(struct npcm_otp_priv));
+	if (!otp_priv)
+		return -ENOMEM;
+
+	regs = dev_remap_addr_index(dev, 0);
+	if (!regs) {
+		printf("Cannot find reg address (arr #0), binding failed\n");
+		return -EINVAL;
+	}
+	otp_priv->regs[0] = regs;
+
+	if (IS_ENABLED(CONFIG_ARCH_NPCM7xx)) {
+		regs = dev_remap_addr_index(dev, 1);
+		if (!regs) {
+			printf("Cannot find reg address (arr #1), binding failed\n");
+			return -EINVAL;
+		}
+		otp_priv->regs[1] = regs;
+	}
+	printf("OTP: NPCM OTP module bind OK\n");
+
+	return 0;
+}
+
+static const struct udevice_id npcm_otp_ids[] = {
+	{ .compatible = "nuvoton,npcm845-otp" },
+	{ .compatible = "nuvoton,npcm750-otp" },
+	{ }
+};
+
+U_BOOT_DRIVER(npcm_otp) = {
+	.name = "npcm_otp",
+	.id = UCLASS_MISC,
+	.of_match = npcm_otp_ids,
+	.priv_auto = sizeof(struct npcm_otp_priv),
+	.bind = npcm_otp_bind,
+};