Add support for unprotected spare data page

index 1a77542c6d67..ec11599ba689 100644
@@ -80,8 +80,10 @@
 #define	DISABLE_STATUS_AFTER_WRITE	4
 #define	CW_PER_PAGE			6
 #define	UD_SIZE_BYTES			9
+#define	UD_SIZE_BYTES_MASK		GENMASK(18, 9)
 #define	ECC_PARITY_SIZE_BYTES_RS	19
 #define	SPARE_SIZE_BYTES		23
+#define	SPARE_SIZE_BYTES_MASK		GENMASK(26, 23)
 #define	NUM_ADDR_CYCLES			27
 #define	STATUS_BFR_READ			30
 #define	SET_RD_MODE_AFTER_STATUS	31

@@ -102,6 +104,7 @@
 #define	ECC_MODE			4
 #define	ECC_PARITY_SIZE_BYTES_BCH	8
 #define	ECC_NUM_DATA_BYTES		16
+#define	ECC_NUM_DATA_BYTES_MASK		GENMASK(25, 16)
 #define	ECC_FORCE_CLK_OPEN		30
 
 /* NAND_DEV_CMD1 bits */

@@ -418,6 +421,19 @@ struct qcom_nand_controller {
 	const struct qcom_nandc_props *props;
 };
 
+/*
+ * NAND special boot pages
+ *
+ * @offset:			offset of the page where spare data is not protected
+ *				by ECC
+ * @size:			size of the page where spare data is not protected
+ *				by ECC
+ */
+struct qcom_nand_boot_page {
+	u32 offset;
+	u32 size;
+};
+
 /*
  * NAND chip structure
  *

@@ -444,6 +460,13 @@ struct qcom_nand_controller {
  * @cfg0, cfg1, cfg0_raw..:	NANDc register configurations needed for
  *				ecc/non-ecc mode for the current nand flash
  *				device
+ *
+ * @unprotect_spare_data:	keep track of the current ecc configuration used by
+ *				the driver for read/write operation.
+ * @boot_pages_count:		count of the boot pages where spare data is not
+ *				protected by ECC
+ * @boot_pages:			array of boot pages where offset and size of the
+ *				boot pages are stored
  */
 struct qcom_nand_host {
 	struct nand_chip chip;

@@ -466,6 +489,10 @@ struct qcom_nand_host {
 	u32 ecc_bch_cfg;
 	u32 clrflashstatus;
 	u32 clrreadstatus;
+
+	bool unprotect_spare_data;
+	int boot_pages_count;
+	struct qcom_nand_boot_page *boot_pages;
 };
 
 /*

@@ -475,6 +502,7 @@ struct qcom_nand_host {
  * @is_bam - whether NAND controller is using BAM
  * @is_qpic - whether NAND CTRL is part of qpic IP
  * @qpic_v2 - flag to indicate QPIC IP version 2
+ * @has_boot_pages - whether NAND has different ecc settings for boot pages
  * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
  */
 struct qcom_nandc_props {

@@ -482,6 +510,7 @@ struct qcom_nandc_props {
 	bool is_bam;
 	bool is_qpic;
 	bool qpic_v2;
+	bool has_boot_pages;
 	u32 dev_cmd_reg_start;
 };
 

@@ -1701,7 +1730,7 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
 	data_size1 = mtd->writesize - host->cw_size * (ecc->steps - 1);
 	oob_size1 = host->bbm_size;
 
-	if (qcom_nandc_is_last_cw(ecc, cw)) {
+	if (qcom_nandc_is_last_cw(ecc, cw) && !host->unprotect_spare_data) {
 		data_size2 = ecc->size - data_size1 -
 			     ((ecc->steps - 1) * 4);
 		oob_size2 = (ecc->steps * 4) + host->ecc_bytes_hw +

@@ -1782,7 +1811,7 @@ check_for_erased_page(struct qcom_nand_host *host, u8 *data_buf,
 	}
 
 	for_each_set_bit(cw, &uncorrectable_cws, ecc->steps) {
-		if (qcom_nandc_is_last_cw(ecc, cw)) {
+		if (qcom_nandc_is_last_cw(ecc, cw) && !host->unprotect_spare_data) {
 			data_size = ecc->size - ((ecc->steps - 1) * 4);
 			oob_size = (ecc->steps * 4) + host->ecc_bytes_hw;
 		} else {

@@ -1940,7 +1969,7 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
 	for (i = 0; i < ecc->steps; i++) {
 		int data_size, oob_size;
 
-		if (qcom_nandc_is_last_cw(ecc, i)) {
+		if (qcom_nandc_is_last_cw(ecc, i) && !host->unprotect_spare_data) {
 			data_size = ecc->size - ((ecc->steps - 1) << 2);
 			oob_size = (ecc->steps << 2) + host->ecc_bytes_hw +
 				   host->spare_bytes;

@@ -2037,6 +2066,52 @@ static int copy_last_cw(struct qcom_nand_host *host, int page)
 	return ret;
 }
 
+static bool
+qcom_nandc_is_boot_page(struct qcom_nand_host *host, int page)
+{
+	struct qcom_nand_boot_page *boot_page;
+	u32 start, end;
+	int i;
+
+	for (i = 0; i < host->boot_pages_count; i++) {
+		boot_page = &host->boot_pages[i];
+		start = boot_page->offset;
+		end = start + boot_page->size;
+		/* Boot page are at the start of the nand.
+		 * Check the page from the boot page end first
+		 * to save one extra check.
+		 */
+		if (page < end && page >= start)
+			return 1;
+	}
+
+	return 0;
+}
+
+static void
+qcom_nandc_check_boot_pages(struct qcom_nand_host *host, int page)
+{
+	bool unprotect_spare_data = qcom_nandc_is_boot_page(host, page);
+
+	/* Skip conf write if we are already in the correct mode */
+	if (unprotect_spare_data == host->unprotect_spare_data)
+		return;
+
+	host->unprotect_spare_data = unprotect_spare_data;
+
+	host->cw_data = unprotect_spare_data ? 512 : 516;
+	host->spare_bytes = host->cw_size - host->ecc_bytes_hw -
+			    host->bbm_size - host->cw_data;
+
+	host->cfg0 &= ~(SPARE_SIZE_BYTES_MASK | UD_SIZE_BYTES_MASK);
+	host->cfg0 |= host->spare_bytes << SPARE_SIZE_BYTES |
+		      host->cw_data << UD_SIZE_BYTES;
+
+	host->ecc_bch_cfg &= ~ECC_NUM_DATA_BYTES_MASK;
+	host->ecc_bch_cfg |= host->cw_data << ECC_NUM_DATA_BYTES;
+	host->ecc_buf_cfg = (unprotect_spare_data ? 0x1ff : 0x203) << NUM_STEPS;
+}
+
 /* implements ecc->read_page() */
 static int qcom_nandc_read_page(struct nand_chip *chip, uint8_t *buf,
 				int oob_required, int page)

@@ -2045,6 +2120,9 @@ static int qcom_nandc_read_page(struct nand_chip *chip, uint8_t *buf,
 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 	u8 *data_buf, *oob_buf = NULL;
 
+	if (host->boot_pages_count)
+		qcom_nandc_check_boot_pages(host, page);
+
 	nand_read_page_op(chip, page, 0, NULL, 0);
 	data_buf = buf;
 	oob_buf = oob_required ? chip->oob_poi : NULL;

@@ -2064,6 +2142,9 @@ static int qcom_nandc_read_page_raw(struct nand_chip *chip, uint8_t *buf,
 	int cw, ret;
 	u8 *data_buf = buf, *oob_buf = chip->oob_poi;
 
+	if (host->boot_pages_count)
+		qcom_nandc_check_boot_pages(host, page);
+
 	for (cw = 0; cw < ecc->steps; cw++) {
 		ret = qcom_nandc_read_cw_raw(mtd, chip, data_buf, oob_buf,
 					     page, cw);

@@ -2084,6 +2165,9 @@ static int qcom_nandc_read_oob(struct nand_chip *chip, int page)
 	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 
+	if (host->boot_pages_count)
+		qcom_nandc_check_boot_pages(host, page);
+
 	clear_read_regs(nandc);
 	clear_bam_transaction(nandc);
 

@@ -2104,6 +2188,9 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const uint8_t *buf,
 	u8 *data_buf, *oob_buf;
 	int i, ret;
 
+	if (host->boot_pages_count)
+		qcom_nandc_check_boot_pages(host, page);
+
 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
 
 	clear_read_regs(nandc);

@@ -2119,7 +2206,7 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const uint8_t *buf,
 	for (i = 0; i < ecc->steps; i++) {
 		int data_size, oob_size;
 
-		if (qcom_nandc_is_last_cw(ecc, i)) {
+		if (qcom_nandc_is_last_cw(ecc, i) && !host->unprotect_spare_data) {
 			data_size = ecc->size - ((ecc->steps - 1) << 2);
 			oob_size = (ecc->steps << 2) + host->ecc_bytes_hw +
 				   host->spare_bytes;

@@ -2176,6 +2263,9 @@ static int qcom_nandc_write_page_raw(struct nand_chip *chip,
 	u8 *data_buf, *oob_buf;
 	int i, ret;
 
+	if (host->boot_pages_count)
+		qcom_nandc_check_boot_pages(host, page);
+
 	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
 	clear_read_regs(nandc);
 	clear_bam_transaction(nandc);

@@ -2194,7 +2284,7 @@ static int qcom_nandc_write_page_raw(struct nand_chip *chip,
 		data_size1 = mtd->writesize - host->cw_size * (ecc->steps - 1);
 		oob_size1 = host->bbm_size;
 
-		if (qcom_nandc_is_last_cw(ecc, i)) {
+		if (qcom_nandc_is_last_cw(ecc, i) && !host->unprotect_spare_data) {
 			data_size2 = ecc->size - data_size1 -
 				     ((ecc->steps - 1) << 2);
 			oob_size2 = (ecc->steps << 2) + host->ecc_bytes_hw +

@@ -2254,6 +2344,9 @@ static int qcom_nandc_write_oob(struct nand_chip *chip, int page)
 	int data_size, oob_size;
 	int ret;
 
+	if (host->boot_pages_count)
+		qcom_nandc_check_boot_pages(host, page);
+
 	host->use_ecc = true;
 	clear_bam_transaction(nandc);
 

@@ -2902,6 +2995,48 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
 
 static const char * const probes[] = { "cmdlinepart", "ofpart", "qcomsmem", NULL };
 
+static int qcom_nand_host_parse_boot_pages(struct qcom_nand_controller *nandc,
+					   struct qcom_nand_host *host,
+					   struct device_node *dn)
+{
+	struct nand_chip *chip = &host->chip;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct qcom_nand_boot_page *boot_page;
+	struct device *dev = nandc->dev;
+	int pages_count, i, ret;
+
+	if (!nandc->props->has_boot_pages)
+		return 0;
+
+	pages_count = of_property_count_u32_elems(dn, "qcom,boot_pages");
+	if (pages_count < 0) {
+		dev_err(dev, "Error parsing boot_pages. Ignoring.");
+		return 0;
+	}
+
+	host->boot_pages_count = pages_count / 2;
+	host->boot_pages = devm_kcalloc(dev, host->boot_pages_count,
+					sizeof(*host->boot_pages), GFP_KERNEL);
+	if (!host->boot_pages)
+		return 0;
+
+	ret = of_property_read_u32_array(dn, "qcom,boot_pages", (u32 *)host->boot_pages,
+					 pages_count);
+	if (ret) {
+		dev_err(dev, "Error reading boot_pages. Ignoring.");
+		return 0;
+	}
+
+	/* Convert offset to nand pages */
+	for (i = 0 ; i < host->boot_pages_count; i++) {
+		boot_page = &host->boot_pages[i];
+		boot_page->offset /= mtd->writesize;
+		boot_page->size /= mtd->writesize;
+	}
+
+	return 0;
+}
+
 static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
 					    struct qcom_nand_host *host,
 					    struct device_node *dn)

@@ -2970,6 +3105,8 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
 	if (ret)
 		nand_cleanup(chip);
 
+	qcom_nand_host_parse_boot_pages(nandc, host, dn);
+
 	return ret;
 }
 

@@ -3135,6 +3272,7 @@ static int qcom_nandc_remove(struct platform_device *pdev)
 static const struct qcom_nandc_props ipq806x_nandc_props = {
 	.ecc_modes = (ECC_RS_4BIT | ECC_BCH_8BIT),
 	.is_bam = false,
+	.has_boot_pages = true,
 	.dev_cmd_reg_start = 0x0,
 };