spi-nor: intel-spi: Fix number of protected range registers for BYT/LPT

The number of protected range registers is not the same on BYT/LPT/
BXT. GPR0 only exists on Apollo Lake and its offset is reserved on
other platforms.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>

drivers/mtd/spi-nor/intel-spi.c

@@ -67,8 +67,6 @@
 #define PR_LIMIT_MASK			(0x3fff << PR_LIMIT_SHIFT)
 #define PR_RPE				BIT(15)
 #define PR_BASE_MASK			0x3fff
-/* Last PR is GPR0 */
-#define PR_NUM				(5 + 1)
 
 /* Offsets are from @ispi->sregs */
 #define SSFSTS_CTL			0x00
@@ -96,14 +94,17 @@
 #define BYT_BCR				0xfc
 #define BYT_BCR_WPD			BIT(0)
 #define BYT_FREG_NUM			5
+#define BYT_PR_NUM			5
 
 #define LPT_PR				0x74
 #define LPT_SSFSTS_CTL			0x90
 #define LPT_FREG_NUM			5
+#define LPT_PR_NUM			5
 
 #define BXT_PR				0x84
 #define BXT_SSFSTS_CTL			0xa0
 #define BXT_FREG_NUM			12
+#define BXT_PR_NUM			6
 
 #define INTEL_SPI_TIMEOUT		5000 /* ms */
 #define INTEL_SPI_FIFO_SZ		64
@@ -117,6 +118,7 @@
  * @pregs: Start of protection registers
  * @sregs: Start of software sequencer registers
  * @nregions: Maximum number of regions
+ * @pr_num: Maximum number of protected range registers
  * @writeable: Is the chip writeable
  * @swseq: Use SW sequencer in register reads/writes
  * @erase_64k: 64k erase supported
@@ -132,6 +134,7 @@ struct intel_spi {
 	void __iomem *pregs;
 	void __iomem *sregs;
 	size_t nregions;
+	size_t pr_num;
 	bool writeable;
 	bool swseq;
 	bool erase_64k;
@@ -167,7 +170,7 @@ static void intel_spi_dump_regs(struct intel_spi *ispi)
 	for (i = 0; i < ispi->nregions; i++)
 		dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
 			readl(ispi->base + FREG(i)));
-	for (i = 0; i < PR_NUM; i++)
+	for (i = 0; i < ispi->pr_num; i++)
 		dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
 			readl(ispi->pregs + PR(i)));
 
@@ -182,7 +185,7 @@ static void intel_spi_dump_regs(struct intel_spi *ispi)
 		dev_dbg(ispi->dev, "BCR=0x%08x\n", readl(ispi->base + BYT_BCR));
 
 	dev_dbg(ispi->dev, "Protected regions:\n");
-	for (i = 0; i < PR_NUM; i++) {
+	for (i = 0; i < ispi->pr_num; i++) {
 		u32 base, limit;
 
 		value = readl(ispi->pregs + PR(i));
@@ -286,6 +289,7 @@ static int intel_spi_init(struct intel_spi *ispi)
 		ispi->sregs = ispi->base + BYT_SSFSTS_CTL;
 		ispi->pregs = ispi->base + BYT_PR;
 		ispi->nregions = BYT_FREG_NUM;
+		ispi->pr_num = BYT_PR_NUM;
 
 		if (writeable) {
 			/* Disable write protection */
@@ -305,12 +309,14 @@ static int intel_spi_init(struct intel_spi *ispi)
 		ispi->sregs = ispi->base + LPT_SSFSTS_CTL;
 		ispi->pregs = ispi->base + LPT_PR;
 		ispi->nregions = LPT_FREG_NUM;
+		ispi->pr_num = LPT_PR_NUM;
 		break;
 
 	case INTEL_SPI_BXT:
 		ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
 		ispi->pregs = ispi->base + BXT_PR;
 		ispi->nregions = BXT_FREG_NUM;
+		ispi->pr_num = BXT_PR_NUM;
 		ispi->erase_64k = true;
 		break;
 
@@ -652,7 +658,7 @@ static bool intel_spi_is_protected(const struct intel_spi *ispi,
 {
 	int i;
 
-	for (i = 0; i < PR_NUM; i++) {
+	for (i = 0; i < ispi->pr_num; i++) {
 		u32 pr_base, pr_limit, pr_value;
 
 		pr_value = readl(ispi->pregs + PR(i));