mfd: sta2x11-mfd: Add sta2x11_mfd_get_regs_data() function

A couple of predefined clocks (mux and gated) need to be
initialized with the virtual address of the clock's controlling
register and the address of a spinlock used to protect against
races.

This function exports such data for all the mfd cells.

Signed-off-by: Davide Ciminaghi <ciminaghi@gnudd.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/sta2x11-mfd.c b/drivers/mfd/sta2x11-mfd.c
index 0cac201..6d12ab4 100644
--- a/drivers/mfd/sta2x11-mfd.c
+++ b/drivers/mfd/sta2x11-mfd.c
@@ -135,6 +135,28 @@
 }
 EXPORT_SYMBOL(__sta2x11_mfd_mask);
 
+int sta2x11_mfd_get_regs_data(struct platform_device *dev,
+			      enum sta2x11_mfd_plat_dev index,
+			      void __iomem **regs,
+			      spinlock_t **lock)
+{
+	struct pci_dev *pdev = *(struct pci_dev **)(dev->dev.platform_data);
+	struct sta2x11_mfd *mfd;
+
+	if (!pdev)
+		return -ENODEV;
+	mfd = sta2x11_mfd_find(pdev);
+	if (!mfd)
+		return -ENODEV;
+	if (index >= sta2x11_n_mfd_plat_devs)
+		return -ENODEV;
+	*regs = mfd->regs[index];
+	*lock = &mfd->lock[index];
+	pr_debug("%s %d *regs = %p\n", __func__, __LINE__, *regs);
+	return *regs ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL(sta2x11_mfd_get_regs_data);
+
 /*
  * Special sta2x11-mfd regmap lock/unlock functions
  */
diff --git a/include/linux/mfd/sta2x11-mfd.h b/include/linux/mfd/sta2x11-mfd.h
index 8334430..e813e5e 100644
--- a/include/linux/mfd/sta2x11-mfd.h
+++ b/include/linux/mfd/sta2x11-mfd.h
@@ -474,4 +474,9 @@
 #define COMPENSATION_REG3		0x3cc
 #define TEST_CTL_REG			0x3d0
 
+extern int sta2x11_mfd_get_regs_data(struct platform_device *pdev,
+				     enum sta2x11_mfd_plat_dev index,
+				     void __iomem **regs,
+				     spinlock_t **lock);
+
 #endif /* __STA2X11_MFD_H */