mfd: Add JZ4740 ADC driver

This patch adds a MFD driver for the JZ4740 ADC unit. The driver is used to
demultiplex IRQs and synchronize access to shared registers between the
battery, hwmon and (future) touchscreen driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/linux/jz4740-adc.h

@@ -0,0 +1,32 @@
+
+#ifndef __LINUX_JZ4740_ADC
+#define __LINUX_JZ4740_ADC
+
+#include <linux/device.h>
+
+/*
+ * jz4740_adc_set_config - Configure a JZ4740 adc device
+ * @dev: Pointer to a jz4740-adc device
+ * @mask: Mask for the config value to be set
+ * @val: Value to be set
+ *
+ * This function can be used by the JZ4740 ADC mfd cells to configure their
+ * options in the shared config register.
+*/
+int jz4740_adc_set_config(struct device *dev, uint32_t mask, uint32_t val);
+
+#define JZ_ADC_CONFIG_SPZZ		BIT(31)
+#define JZ_ADC_CONFIG_EX_IN		BIT(30)
+#define JZ_ADC_CONFIG_DNUM_MASK		(0x7 << 16)
+#define JZ_ADC_CONFIG_DMA_ENABLE	BIT(15)
+#define JZ_ADC_CONFIG_XYZ_MASK		(0x2 << 13)
+#define JZ_ADC_CONFIG_SAMPLE_NUM_MASK	(0x7 << 10)
+#define JZ_ADC_CONFIG_CLKDIV_MASK	(0xf << 5)
+#define JZ_ADC_CONFIG_BAT_MB		BIT(4)
+
+#define JZ_ADC_CONFIG_DNUM(dnum)	((dnum) << 16)
+#define JZ_ADC_CONFIG_XYZ_OFFSET(dnum)	((xyz) << 13)
+#define JZ_ADC_CONFIG_SAMPLE_NUM(x)	((x) << 10)
+#define JZ_ADC_CONFIG_CLKDIV(div)	((div) << 5)
+
+#endif