soc: mediatek: pwrap: Move PMIC read test sequence in function

The PMIC read test is performed in two places: pwrap_init_dual_io()
and pwrap_init_sidly().
In preparation for adding support for PMICs requiring a companion
part, move this sequence to a new function pwrap_pmic_read_test().

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://lore.kernel.org/r/20230412131216.198313-3-angelogioacchino.delregno@collabora.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Author: AngeloGioacchino Del Regno

drivers/soc/mediatek/mtk-pmic-wrap.c

@@ -1455,6 +1455,18 @@ static int pwrap_regmap_write(void *context, u32 adr, u32 wdata)
 	return pwrap_write(context, adr, wdata);
 }
 
+static bool pwrap_pmic_read_test(struct pmic_wrapper *wrp, const u32 *dew_regs,
+				 u16 read_test_val)
+{
+	bool is_success;
+	u32 rdata;
+
+	pwrap_read(wrp, dew_regs[PWRAP_DEW_READ_TEST], &rdata);
+	is_success = ((rdata & U16_MAX) == read_test_val);
+
+	return is_success;
+}
+
 static int pwrap_reset_spislave(struct pmic_wrapper *wrp)
 {
 	bool tmp;
@@ -1498,18 +1510,18 @@ static int pwrap_reset_spislave(struct pmic_wrapper *wrp)
  */
 static int pwrap_init_sidly(struct pmic_wrapper *wrp)
 {
-	u32 rdata;
 	u32 i;
 	u32 pass = 0;
+	bool read_ok;
 	signed char dly[16] = {
 		-1, 0, 1, 0, 2, -1, 1, 1, 3, -1, -1, -1, 3, -1, 2, 1
 	};
 
 	for (i = 0; i < 4; i++) {
 		pwrap_writel(wrp, i, PWRAP_SIDLY);
-		pwrap_read(wrp, wrp->slave->dew_regs[PWRAP_DEW_READ_TEST],
-			   &rdata);
-		if (rdata == PWRAP_DEW_READ_TEST_VAL) {
+		read_ok = pwrap_pmic_read_test(wrp, wrp->slave->dew_regs,
+					       PWRAP_DEW_READ_TEST_VAL);
+		if (read_ok) {
 			dev_dbg(wrp->dev, "[Read Test] pass, SIDLY=%x\n", i);
 			pass |= 1 << i;
 		}
@@ -1529,8 +1541,7 @@ static int pwrap_init_sidly(struct pmic_wrapper *wrp)
 static int pwrap_init_dual_io(struct pmic_wrapper *wrp)
 {
 	int ret;
-	bool tmp;
-	u32 rdata;
+	bool read_ok, tmp;
 
 	/* Enable dual IO mode */
 	pwrap_write(wrp, wrp->slave->dew_regs[PWRAP_DEW_DIO_EN], 1);
@@ -1546,12 +1557,9 @@ static int pwrap_init_dual_io(struct pmic_wrapper *wrp)
 	pwrap_writel(wrp, 1, PWRAP_DIO_EN);
 
 	/* Read Test */
-	pwrap_read(wrp,
-		   wrp->slave->dew_regs[PWRAP_DEW_READ_TEST], &rdata);
-	if (rdata != PWRAP_DEW_READ_TEST_VAL) {
-		dev_err(wrp->dev,
-			"Read failed on DIO mode: 0x%04x!=0x%04x\n",
-			PWRAP_DEW_READ_TEST_VAL, rdata);
+	read_ok = pwrap_pmic_read_test(wrp, wrp->slave->dew_regs, PWRAP_DEW_READ_TEST_VAL);
+	if (!read_ok) {
+		dev_err(wrp->dev, "Read failed on DIO mode.\n");
 		return -EFAULT;
 	}