spi: hisi-sfc-v3xx: add error check after per operation

The controller may receive instructions of accessing protected address,
or may perform failed page program. These operations will not succeed
and the controller will receive interrupts when such failure occur.
Previously we don't check the interrupts and return 0 even if such
operation fails.

Check the interrupts after per command and inform the user
if there is an error.
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Acked-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1587109707-23597-1-git-send-email-yangyicong@hisilicon.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-hisi-sfc-v3xx.c

@@ -17,6 +17,11 @@
 
 #define HISI_SFC_V3XX_VERSION (0x1f8)
 
+#define HISI_SFC_V3XX_INT_STAT (0x120)
+#define HISI_SFC_V3XX_INT_STAT_PP_ERR BIT(2)
+#define HISI_SFC_V3XX_INT_STAT_ADDR_IACCES BIT(5)
+#define HISI_SFC_V3XX_INT_CLR (0x12c)
+#define HISI_SFC_V3XX_INT_CLR_CLEAR (0xff)
 #define HISI_SFC_V3XX_CMD_CFG (0x300)
 #define HISI_SFC_V3XX_CMD_CFG_DUAL_IN_DUAL_OUT (1 << 17)
 #define HISI_SFC_V3XX_CMD_CFG_DUAL_IO (2 << 17)
@@ -163,7 +168,7 @@ static int hisi_sfc_v3xx_generic_exec_op(struct hisi_sfc_v3xx_host *host,
 					 u8 chip_select)
 {
 	int ret, len = op->data.nbytes;
-	u32 config = 0;
+	u32 int_stat, config = 0;
 
 	if (op->addr.nbytes)
 		config |= HISI_SFC_V3XX_CMD_CFG_ADDR_EN_MSK;
@@ -228,6 +233,25 @@ static int hisi_sfc_v3xx_generic_exec_op(struct hisi_sfc_v3xx_host *host,
 	if (ret)
 		return ret;
 
+	/*
+	 * The interrupt status register indicates whether an error occurs
+	 * after per operation. Check it, and clear the interrupts for
+	 * next time judgement.
+	 */
+	int_stat = readl(host->regbase + HISI_SFC_V3XX_INT_STAT);
+	writel(HISI_SFC_V3XX_INT_CLR_CLEAR,
+	       host->regbase + HISI_SFC_V3XX_INT_CLR);
+
+	if (int_stat & HISI_SFC_V3XX_INT_STAT_ADDR_IACCES) {
+		dev_err(host->dev, "fail to access protected address\n");
+		return -EIO;
+	}
+
+	if (int_stat & HISI_SFC_V3XX_INT_STAT_PP_ERR) {
+		dev_err(host->dev, "page program operation failed\n");
+		return -EIO;
+	}
+
 	if (op->data.dir == SPI_MEM_DATA_IN)
 		hisi_sfc_v3xx_read_databuf(host, op->data.buf.in, len);