mfd: stmfx: wait boot time after a regulator enable

VCASTM · ashishverma2691 · commit 74cc379a37fe · 2024-07-25T14:42:13.000+05:30
STMFX has a boot time of 10ms between reset and first register access. But this delay is not yet respected after a regulator_enable, and sometimes register access could failed with -ENXIO. As we cannot get the time since the regulator was enabled, we poll every 1ms the STMFX_REG_FW_VERSION_MSB, to wait the completed boot of chip. A timeout is set to 10ms. Change-Id: I2eeeccac00fc6087d60cd30dbb7fad4c30a72e1b Signed-off-by: Valentin Caron <valentin.caron@foss.st.com> Signed-off-by: Deepak kumar <deepak.kumar01@st.com> Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/369823 Domain-Review: Amelie DELAUNAY <amelie.delaunay@foss.st.com> ACI: CIBUILD <MDG-smet-aci-builds@list.st.com> ACI: CITOOLS <MDG-smet-aci-reviews@list.st.com> Reviewed-by: Amelie DELAUNAY <amelie.delaunay@foss.st.com>
diff --git a/drivers/mfd/stmfx.c b/drivers/mfd/stmfx.c
@@ -304,6 +304,21 @@ static int stmfx_irq_init(struct i2c_client *client)
 	return ret;
 }
 
+static int stmfx_chip_wait_boot(struct stmfx *stmfx)
+{
+	unsigned long timeout_ms = 0;
+	unsigned int val;
+	int ret;
+
+	while (1) {
+		ret = regmap_read(stmfx->map, STMFX_REG_FW_VERSION_MSB, &val);
+		if (ret != -ENXIO || timeout_ms > STMFX_BOOT_TIME_MS)
+			return ret;
+		mdelay(1);
+		timeout_ms++;
+	}
+}
+
 static int stmfx_chip_reset(struct stmfx *stmfx)
 {
 	int ret;
@@ -340,6 +355,11 @@ static int stmfx_chip_init(struct i2c_client *client)
 			return ret;
 		}
 	}
+	ret = stmfx_chip_wait_boot(stmfx);
+	if (ret) {
+		dev_err(stmfx->dev, "Boot chip failed: %d\n", ret);
+		return ret;
+	}
 
 	ret = regmap_read(stmfx->map, STMFX_REG_CHIP_ID, &id);
 	if (ret) {
@@ -504,6 +524,11 @@ static int stmfx_resume(struct device *dev)
 			return ret;
 		}
 	}
+	ret = stmfx_chip_wait_boot(stmfx);
+	if (ret) {
+		dev_err(stmfx->dev, "Boot chip failed: %d\n", ret);
+		return ret;
+	}
 
 	/* Reset STMFX - supply has been stopped during suspend */
 	ret = stmfx_chip_reset(stmfx);
