thermal: qcom: tsens: Add a skeletal TSENS drivers

TSENS is Qualcomms' thermal temperature sensor device. It
supports reading temperatures from multiple thermal sensors
present on various QCOM SoCs.
Calibration data is generally read from a non-volatile memory
(eeprom) device.

Add a skeleton driver with all the necessary abstractions so
a variety of qcom device families which support TSENS can
add driver extensions.

Also add the required device tree bindings which can be used
to describe the TSENS device in DT.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 90 insertions, 0 deletions

diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
new file mode 100644
index 000000000000..3b1b6ae82a47
--- /dev/null
+++ b/drivers/thermal/qcom/tsens.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __QCOM_TSENS_H__
+#define __QCOM_TSENS_H__
+
+#define ONE_PT_CALIB		0x1
+#define ONE_PT_CALIB2		0x2
+#define TWO_PT_CALIB		0x3
+
+struct tsens_device;
+
+struct tsens_sensor {
+	struct tsens_device		*tmdev;
+	struct thermal_zone_device	*tzd;
+	int				offset;
+	int				id;
+	int				hw_id;
+	int				slope;
+	u32				status;
+};
+
+/**
+ * struct tsens_ops - operations as supported by the tsens device
+ * @init: Function to initialize the tsens device
+ * @calibrate: Function to calibrate the tsens device
+ * @get_temp: Function which returns the temp in millidegC
+ * @enable: Function to enable (clocks/power) tsens device
+ * @disable: Function to disable the tsens device
+ * @suspend: Function to suspend the tsens device
+ * @resume: Function to resume the tsens device
+ * @get_trend: Function to get the thermal/temp trend
+ */
+struct tsens_ops {
+	/* mandatory callbacks */
+	int (*init)(struct tsens_device *);
+	int (*calibrate)(struct tsens_device *);
+	int (*get_temp)(struct tsens_device *, int, int *);
+	/* optional callbacks */
+	int (*enable)(struct tsens_device *, int);
+	void (*disable)(struct tsens_device *);
+	int (*suspend)(struct tsens_device *);
+	int (*resume)(struct tsens_device *);
+	int (*get_trend)(struct tsens_device *, int, long *);
+};
+
+/**
+ * struct tsens_data - tsens instance specific data
+ * @num_sensors: Max number of sensors supported by platform
+ * @ops: operations the tsens instance supports
+ * @hw_ids: Subset of sensors ids supported by platform, if not the first n
+ */
+struct tsens_data {
+	const u32		num_sensors;
+	const struct tsens_ops	*ops;
+	unsigned int		*hw_ids;
+};
+
+/* Registers to be saved/restored across a context loss */
+struct tsens_context {
+	int	threshold;
+	int	control;
+};
+
+struct tsens_device {
+	struct device			*dev;
+	u32				num_sensors;
+	struct regmap			*map;
+	struct regmap_field		*status_field;
+	struct tsens_context		ctx;
+	bool				trdy;
+	const struct tsens_ops		*ops;
+	struct tsens_sensor		sensor[0];
+};
+
+char *qfprom_read(struct device *, const char *);
+void compute_intercept_slope(struct tsens_device *, u32 *, u32 *, u32);
+int init_common(struct tsens_device *);
+int get_temp_common(struct tsens_device *, int, int *);
+
+#endif /* __QCOM_TSENS_H__ */