hwmon: Add Gateworks System Controller support

The Gateworks System Controller has a hwmon sub-component that exposes
up to 16 ADC's, some of which are temperature sensors, others which are
voltage inputs. The ADC configuration (register mapping and name) is
configured via device-tree and varies board to board.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/include/linux/platform_data/gsc_hwmon.h b/include/linux/platform_data/gsc_hwmon.h
new file mode 100644
index 000000000000..ec1611aff863
--- /dev/null
+++ b/include/linux/platform_data/gsc_hwmon.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _GSC_HWMON_H
+#define _GSC_HWMON_H
+
+enum gsc_hwmon_mode {
+	mode_temperature,
+	mode_voltage,
+	mode_voltage_raw,
+	mode_max,
+};
+
+/**
+ * struct gsc_hwmon_channel - configuration parameters
+ * @reg:  I2C register offset
+ * @mode: channel mode
+ * @name: channel name
+ * @mvoffset: voltage offset
+ * @vdiv: voltage divider array (2 resistor values in milli-ohms)
+ */
+struct gsc_hwmon_channel {
+	unsigned int reg;
+	unsigned int mode;
+	const char *name;
+	unsigned int mvoffset;
+	unsigned int vdiv[2];
+};
+
+/**
+ * struct gsc_hwmon_platform_data - platform data for gsc_hwmon driver
+ * @channels:	pointer to array of gsc_hwmon_channel structures
+ *		describing channels
+ * @nchannels:	number of elements in @channels array
+ * @vreference: voltage reference (mV)
+ * @resolution: ADC bit resolution
+ * @fan_base: register base for FAN controller
+ */
+struct gsc_hwmon_platform_data {
+	const struct gsc_hwmon_channel *channels;
+	int nchannels;
+	unsigned int resolution;
+	unsigned int vreference;
+	unsigned int fan_base;
+};
+#endif