From 214f0d9264f9b8c3b847a2ba2286c5ca5a33ab10 Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Thu, 8 May 2014 08:36:19 +0200
Subject: [PATCH] mfd: mc13xxx: Allow to set callback for mc13xxx

Some boards have to initialize the PMIC before other devices can
be initialized. This requires three levels of initcalls: one level
in which the PMIC is probed, one in which the board can call mc13xxx_get()
and the third one to initialize the PMIC dependent devices.

Allow to register a callback which is called once the PMIC is initialized.
This way mc13xxx_get() is no longer necessary and the number of required
initcalls levels is reduced to two.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/mfd/mc13xxx.c | 18 ++++++++++++++++++
 include/mfd/mc13xxx.h |  6 ++++++
 2 files changed, 24 insertions(+)

diff --git a/drivers/mfd/mc13xxx.c b/drivers/mfd/mc13xxx.c
index bfbd32832..eabd5c472 100644
--- a/drivers/mfd/mc13xxx.c
+++ b/drivers/mfd/mc13xxx.c
@@ -60,6 +60,21 @@ int mc13xxx_revision(struct mc13xxx *mc13xxx)
 }
 EXPORT_SYMBOL(mc13xxx_revision);
 
+static void(*mc13xxx_init_callback)(struct mc13xxx *mc13xxx);
+
+int mc13xxx_register_init_callback(void(*callback)(struct mc13xxx *mc13xxx))
+{
+	if (mc13xxx_init_callback)
+		return -EBUSY;
+
+	mc13xxx_init_callback = callback;
+
+	if (mc_dev)
+		mc13xxx_init_callback(mc_dev);
+
+	return 0;
+}
+
 #ifdef CONFIG_SPI
 static int spi_rw(struct spi_device *spi, void * buf, size_t len)
 {
@@ -350,6 +365,9 @@ static int __init mc13xxx_probe(struct device_d *dev)
 	mc_dev->revision = rev;
 	devfs_create(&mc_dev->cdev);
 
+	if (mc13xxx_init_callback)
+		mc13xxx_init_callback(mc_dev);
+
 	return 0;
 }
 
diff --git a/include/mfd/mc13xxx.h b/include/mfd/mc13xxx.h
index 1946b1a1c..96a32e4da 100644
--- a/include/mfd/mc13xxx.h
+++ b/include/mfd/mc13xxx.h
@@ -171,6 +171,7 @@ extern int mc13xxx_revision(struct mc13xxx *mc13xxx);
 extern int mc13xxx_reg_read(struct mc13xxx *mc13xxx, u8 reg, u32 *val);
 extern int mc13xxx_reg_write(struct mc13xxx *mc13xxx, u8 reg, u32 val);
 extern int mc13xxx_set_bits(struct mc13xxx *mc13xxx, u8 reg, u32 mask, u32 val);
+int mc13xxx_register_init_callback(void(*callback)(struct mc13xxx *mc13xxx));
 #else
 static inline struct mc13xxx *mc13xxx_get(void)
 {
@@ -196,6 +197,11 @@ static inline int mc13xxx_set_bits(struct mc13xxx *mc13xxx, u8 reg, u32 mask, u3
 {
 	return -ENODEV;
 }
+
+static inline int mc13xxx_register_init_callback(void(*callback)(struct mc13xxx *mc13xxx))
+{
+	return -ENODEV;
+}
 #endif
 
 #endif /* __MFD_MC13XXX_H */