mfd: pm8xxx-misc: Add API to read PMIC registers
This API reads the PMIC registers at runtime and can be called
from process/interrupt context. It is currently enabled for PM8921.
Change-Id: I63a80293e37725569d075de814f27f67382976ca
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>
diff --git a/drivers/mfd/pm8xxx-misc.c b/drivers/mfd/pm8xxx-misc.c
index 59b4dd9..6da845d 100644
--- a/drivers/mfd/pm8xxx-misc.c
+++ b/drivers/mfd/pm8xxx-misc.c
@@ -182,6 +182,41 @@
return rc;
}
+/**
+ * pm8xxx_read_register - Read a PMIC register
+ * @addr: PMIC register address
+ * @value: Output parameter which gets the value of the register read.
+ * RETURNS: an appropriate -ERRNO error value on error, or zero for success.
+ */
+int pm8xxx_read_register(u16 addr, u8 *value)
+{
+ struct pm8xxx_misc_chip *chip;
+ unsigned long flags;
+ int rc = 0;
+
+ spin_lock_irqsave(&pm8xxx_misc_chips_lock, flags);
+
+ /* Loop over all attached PMICs and call specific functions for them. */
+ list_for_each_entry(chip, &pm8xxx_misc_chips, link) {
+ switch (chip->version) {
+ case PM8XXX_VERSION_8921:
+ rc = pm8xxx_readb(chip->dev->parent, addr, value);
+ if (rc) {
+ pr_err("pm8xxx_readb(0x%03X) failed, rc=%d\n",
+ addr, rc);
+ break;
+ }
+ default:
+ break;
+ }
+ }
+
+ spin_unlock_irqrestore(&pm8xxx_misc_chips_lock, flags);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(pm8xxx_read_register);
+
/*
* Set an SMPS regulator to be disabled in its CTRL register, but enabled
* in the master enable register. Also set it's pull down enable bit.