staging: OMAP4+: thermal: introduce bandgap temperature sensor

In the System Control Module, OMAP supplies a voltage reference
and a temperature sensor feature that are gathered in the band
gap voltage and temperature sensor (VBGAPTS) module. The band
gap provides current and voltage reference for its internal
circuits and other analog IP blocks. The analog-to-digital
converter (ADC) produces an output value that is proportional
to the silicon temperature.

This patch provides a platform driver which expose this feature.
It is moduled as a MFD child of the System Control Module core
MFD driver.

This driver provides only APIs to access the device properties,
like temperature, thresholds and update rate.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: J Keerthy <j-keerthy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1167 insertions, 0 deletions

diff --git a/drivers/staging/omap-thermal/omap-bandgap.c b/drivers/staging/omap-thermal/omap-bandgap.c
new file mode 100644
index 000000000000..8ea626406a34
--- /dev/null
+++ b/drivers/staging/omap-thermal/omap-bandgap.c
@@ -0,0 +1,1167 @@
+/*
+ * OMAP4 Bandgap temperature sensor driver
+ *
+ * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
+ * Author: J Keerthy <j-keerthy@ti.com>
+ * Author: Moiz Sonasath <m-sonasath@ti.com>
+ * Couple of fixes, DT and MFD adaptation:
+ *   Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/reboot.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+
+#include "omap-bandgap.h"
+
+static u32 omap_bandgap_readl(struct omap_bandgap *bg_ptr, u32 reg)
+{
+	return readl(bg_ptr->base + reg);
+}
+
+static void omap_bandgap_writel(struct omap_bandgap *bg_ptr, u32 val, u32 reg)
+{
+	writel(val, bg_ptr->base + reg);
+}
+
+static int omap_bandgap_power(struct omap_bandgap *bg_ptr, bool on)
+{
+	struct temp_sensor_registers *tsr;
+	int i;
+	u32 ctrl;
+
+	if (!OMAP_BANDGAP_HAS(bg_ptr, POWER_SWITCH))
+		return 0;
+
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		tsr = bg_ptr->conf->sensors[i].registers;
+		ctrl = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+		ctrl &= ~tsr->bgap_tempsoff_mask;
+		/* active on 0 */
+		ctrl |= !on << __ffs(tsr->bgap_tempsoff_mask);
+
+		/* write BGAP_TEMPSOFF should be reset to 0 */
+		omap_bandgap_writel(bg_ptr, ctrl, tsr->temp_sensor_ctrl);
+	}
+
+	return 0;
+}
+
+/* This is the Talert handler. Call it only if HAS(TALERT) is set */
+static irqreturn_t talert_irq_handler(int irq, void *data)
+{
+	struct omap_bandgap *bg_ptr = data;
+	struct temp_sensor_registers *tsr;
+	u32 t_hot = 0, t_cold = 0, temp, ctrl;
+	int i;
+
+	bg_ptr = data;
+	/* Read the status of t_hot */
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		tsr = bg_ptr->conf->sensors[i].registers;
+		t_hot = omap_bandgap_readl(bg_ptr, tsr->bgap_status);
+		t_hot &= tsr->status_hot_mask;
+
+		/* Read the status of t_cold */
+		t_cold = omap_bandgap_readl(bg_ptr, tsr->bgap_status);
+		t_cold &= tsr->status_cold_mask;
+
+		if (!t_cold && !t_hot)
+			continue;
+
+		ctrl = omap_bandgap_readl(bg_ptr, tsr->bgap_mask_ctrl);
+		/*
+		 * One TALERT interrupt: Two sources
+		 * If the interrupt is due to t_hot then mask t_hot and
+		 * and unmask t_cold else mask t_cold and unmask t_hot
+		 */
+		if (t_hot) {
+			ctrl &= ~tsr->mask_hot_mask;
+			ctrl |= tsr->mask_cold_mask;
+		} else if (t_cold) {
+			ctrl &= ~tsr->mask_cold_mask;
+			ctrl |= tsr->mask_hot_mask;
+		}
+
+		omap_bandgap_writel(bg_ptr, ctrl, tsr->bgap_mask_ctrl);
+
+		/* read temperature */
+		temp = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+		temp &= tsr->bgap_dtemp_mask;
+
+		/* report temperature to whom may concern */
+		if (bg_ptr->conf->report_temperature)
+			bg_ptr->conf->report_temperature(bg_ptr, i);
+	}
+
+	return IRQ_HANDLED;
+}
+
+/* This is the Tshut handler. Call it only if HAS(TSHUT) is set */
+static irqreturn_t omap_bandgap_tshut_irq_handler(int irq, void *data)
+{
+	orderly_poweroff(true);
+
+	return IRQ_HANDLED;
+}
+
+static
+int adc_to_temp_conversion(struct omap_bandgap *bg_ptr, int id, int adc_val,
+			   int *t)
+{
+	struct temp_sensor_data *ts_data = bg_ptr->conf->sensors[id].ts_data;
+
+	/* look up for temperature in the table and return the temperature */
+	if (adc_val < ts_data->adc_start_val || adc_val > ts_data->adc_end_val)
+		return -ERANGE;
+
+	*t = bg_ptr->conv_table[adc_val - ts_data->adc_start_val];
+
+	return 0;
+}
+
+static int temp_to_adc_conversion(long temp, struct omap_bandgap *bg_ptr, int i,
+				  int *adc)
+{
+	struct temp_sensor_data *ts_data = bg_ptr->conf->sensors[i].ts_data;
+	int high, low, mid;
+
+	low = 0;
+	high = ts_data->adc_end_val - ts_data->adc_start_val;
+	mid = (high + low) / 2;
+
+	if (temp < bg_ptr->conv_table[high] || temp > bg_ptr->conv_table[high])
+		return -EINVAL;
+
+	while (low < high) {
+		if (temp < bg_ptr->conv_table[mid])
+			high = mid - 1;
+		else
+			low = mid + 1;
+		mid = (low + high) / 2;
+	}
+
+	*adc = ts_data->adc_start_val + low;
+
+	return 0;
+}
+
+/* Talert masks. Call it only if HAS(TALERT) is set */
+static int temp_sensor_unmask_interrupts(struct omap_bandgap *bg_ptr, int id,
+					 u32 t_hot, u32 t_cold)
+{
+	struct temp_sensor_registers *tsr;
+	u32 temp, reg_val;
+
+	/* Read the current on die temperature */
+	tsr = bg_ptr->conf->sensors[id].registers;
+	temp = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+	temp &= tsr->bgap_dtemp_mask;
+
+	reg_val = omap_bandgap_readl(bg_ptr, tsr->bgap_mask_ctrl);
+	if (temp < t_hot)
+		reg_val |= tsr->mask_hot_mask;
+	else
+		reg_val &= ~tsr->mask_hot_mask;
+
+	if (t_cold < temp)
+		reg_val |= tsr->mask_cold_mask;
+	else
+		reg_val &= ~tsr->mask_cold_mask;
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_mask_ctrl);
+
+	return 0;
+}
+
+static
+int add_hyst(int adc_val, int hyst_val, struct omap_bandgap *bg_ptr, int i,
+	     u32 *sum)
+{
+	int temp, ret;
+
+	ret = adc_to_temp_conversion(bg_ptr, i, adc_val, &temp);
+	if (ret < 0)
+		return ret;
+
+	temp += hyst_val;
+
+	return temp_to_adc_conversion(temp, bg_ptr, i, sum);
+}
+
+/* Talert Thot threshold. Call it only if HAS(TALERT) is set */
+static
+int temp_sensor_configure_thot(struct omap_bandgap *bg_ptr, int id, int t_hot)
+{
+	struct temp_sensor_data *ts_data = bg_ptr->conf->sensors[id].ts_data;
+	struct temp_sensor_registers *tsr;
+	u32 thresh_val, reg_val;
+	int cold, err = 0;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+
+	/* obtain the T cold value */
+	thresh_val = omap_bandgap_readl(bg_ptr, tsr->bgap_threshold);
+	cold = (thresh_val & tsr->threshold_tcold_mask) >>
+	    __ffs(tsr->threshold_tcold_mask);
+	if (t_hot <= cold) {
+		/* change the t_cold to t_hot - 5000 millidegrees */
+		err |= add_hyst(t_hot, -ts_data->hyst_val, bg_ptr, id, &cold);
+		/* write the new t_cold value */
+		reg_val = thresh_val & (~tsr->threshold_tcold_mask);
+		reg_val |= cold << __ffs(tsr->threshold_tcold_mask);
+		omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_threshold);
+		thresh_val = reg_val;
+	}
+
+	/* write the new t_hot value */
+	reg_val = thresh_val & ~tsr->threshold_thot_mask;
+	reg_val |= (t_hot << __ffs(tsr->threshold_thot_mask));
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_threshold);
+	if (err) {
+		dev_err(bg_ptr->dev, "failed to reprogram thot threshold\n");
+		return -EIO;
+	}
+
+	return temp_sensor_unmask_interrupts(bg_ptr, id, t_hot, cold);
+}
+
+/* Talert Thot and Tcold thresholds. Call it only if HAS(TALERT) is set */
+static
+int temp_sensor_init_talert_thresholds(struct omap_bandgap *bg_ptr, int id,
+				       int t_hot, int t_cold)
+{
+	struct temp_sensor_registers *tsr;
+	u32 reg_val, thresh_val;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	thresh_val = omap_bandgap_readl(bg_ptr, tsr->bgap_threshold);
+
+	/* write the new t_cold value */
+	reg_val = thresh_val & ~tsr->threshold_tcold_mask;
+	reg_val |= (t_cold << __ffs(tsr->threshold_tcold_mask));
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_threshold);
+
+	thresh_val = omap_bandgap_readl(bg_ptr, tsr->bgap_threshold);
+
+	/* write the new t_hot value */
+	reg_val = thresh_val & ~tsr->threshold_thot_mask;
+	reg_val |= (t_hot << __ffs(tsr->threshold_thot_mask));
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_threshold);
+
+	reg_val = omap_bandgap_readl(bg_ptr, tsr->bgap_mask_ctrl);
+	reg_val |= tsr->mask_hot_mask;
+	reg_val |= tsr->mask_cold_mask;
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_mask_ctrl);
+
+	return 0;
+}
+
+/* Talert Tcold threshold. Call it only if HAS(TALERT) is set */
+static
+int temp_sensor_configure_tcold(struct omap_bandgap *bg_ptr, int id,
+				int t_cold)
+{
+	struct temp_sensor_data *ts_data = bg_ptr->conf->sensors[id].ts_data;
+	struct temp_sensor_registers *tsr;
+	u32 thresh_val, reg_val;
+	int hot, err = 0;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	/* obtain the T cold value */
+	thresh_val = omap_bandgap_readl(bg_ptr, tsr->bgap_threshold);
+	hot = (thresh_val & tsr->threshold_thot_mask) >>
+	    __ffs(tsr->threshold_thot_mask);
+
+	if (t_cold >= hot) {
+		/* change the t_hot to t_cold + 5000 millidegrees */
+		err |= add_hyst(t_cold, ts_data->hyst_val, bg_ptr, id, &hot);
+		/* write the new t_hot value */
+		reg_val = thresh_val & (~tsr->threshold_thot_mask);
+		reg_val |= hot << __ffs(tsr->threshold_thot_mask);
+		omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_threshold);
+		thresh_val = reg_val;
+	}
+
+	/* write the new t_cold value */
+	reg_val = thresh_val & ~tsr->threshold_tcold_mask;
+	reg_val |= (t_cold << __ffs(tsr->threshold_tcold_mask));
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->bgap_threshold);
+	if (err) {
+		dev_err(bg_ptr->dev, "failed to reprogram tcold threshold\n");
+		return -EIO;
+	}
+
+	return temp_sensor_unmask_interrupts(bg_ptr, id, hot, t_cold);
+}
+
+/* This is Tshut Thot config. Call it only if HAS(TSHUT_CONFIG) is set */
+static int temp_sensor_configure_tshut_hot(struct omap_bandgap *bg_ptr,
+					   int id, int tshut_hot)
+{
+	struct temp_sensor_registers *tsr;
+	u32 reg_val;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	reg_val = omap_bandgap_readl(bg_ptr, tsr->tshut_threshold);
+	reg_val &= ~tsr->tshut_hot_mask;
+	reg_val |= tshut_hot << __ffs(tsr->tshut_hot_mask);
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->tshut_threshold);
+
+	return 0;
+}
+
+/* This is Tshut Tcold config. Call it only if HAS(TSHUT_CONFIG) is set */
+static int temp_sensor_configure_tshut_cold(struct omap_bandgap *bg_ptr,
+					    int id, int tshut_cold)
+{
+	struct temp_sensor_registers *tsr;
+	u32 reg_val;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	reg_val = omap_bandgap_readl(bg_ptr, tsr->tshut_threshold);
+	reg_val &= ~tsr->tshut_cold_mask;
+	reg_val |= tshut_cold << __ffs(tsr->tshut_cold_mask);
+	omap_bandgap_writel(bg_ptr, reg_val, tsr->tshut_threshold);
+
+	return 0;
+}
+
+/* This is counter config. Call it only if HAS(COUNTER) is set */
+static int configure_temp_sensor_counter(struct omap_bandgap *bg_ptr, int id,
+					 u32 counter)
+{
+	struct temp_sensor_registers *tsr;
+	u32 val;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	val = omap_bandgap_readl(bg_ptr, tsr->bgap_counter);
+	val &= ~tsr->counter_mask;
+	val |= counter << __ffs(tsr->counter_mask);
+	omap_bandgap_writel(bg_ptr, val, tsr->bgap_counter);
+
+	return 0;
+}
+
+#define bandgap_is_valid(b)						\
+			(!IS_ERR_OR_NULL(b))
+#define bandgap_is_valid_sensor_id(b, i)				\
+			((i) >= 0 && (i) < (b)->conf->sensor_count)
+static inline int omap_bandgap_validate(struct omap_bandgap *bg_ptr, int id)
+{
+	if (!bandgap_is_valid(bg_ptr)) {
+		pr_err("%s: invalid bandgap pointer\n", __func__);
+		return -EINVAL;
+	}
+
+	if (!bandgap_is_valid_sensor_id(bg_ptr, id)) {
+		dev_err(bg_ptr->dev, "%s: sensor id out of range (%d)\n",
+			__func__, id);
+		return -ERANGE;
+	}
+
+	return 0;
+}
+
+/* Exposed APIs */
+/**
+ * omap_bandgap_read_thot() - reads sensor current thot
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @thot - resulting current thot value
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_read_thot(struct omap_bandgap *bg_ptr, int id,
+			      int *thot)
+{
+	struct temp_sensor_registers *tsr;
+	u32 temp;
+	int ret;
+
+	ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	if (!OMAP_BANDGAP_HAS(bg_ptr, TALERT))
+		return -ENOTSUPP;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	temp = omap_bandgap_readl(bg_ptr, tsr->bgap_threshold);
+	temp = (temp & tsr->threshold_thot_mask) >>
+		__ffs(tsr->threshold_thot_mask);
+	ret |= adc_to_temp_conversion(bg_ptr, id, temp, &temp);
+	if (ret) {
+		dev_err(bg_ptr->dev, "failed to read thot\n");
+		return -EIO;
+	}
+
+	*thot = temp;
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_write_thot() - sets sensor current thot
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @val - desired thot value
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_write_thot(struct omap_bandgap *bg_ptr, int id, int val)
+{
+	struct temp_sensor_data *ts_data;
+	struct temp_sensor_registers *tsr;
+	u32 t_hot;
+	int ret;
+
+	ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	if (!OMAP_BANDGAP_HAS(bg_ptr, TALERT))
+		return -ENOTSUPP;
+
+	ts_data = bg_ptr->conf->sensors[id].ts_data;
+	tsr = bg_ptr->conf->sensors[id].registers;
+
+	if (val < ts_data->min_temp + ts_data->hyst_val)
+		return -EINVAL;
+	ret = temp_to_adc_conversion(val, bg_ptr, id, &t_hot);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&bg_ptr->bg_mutex);
+	temp_sensor_configure_thot(bg_ptr, id, t_hot);
+	mutex_unlock(&bg_ptr->bg_mutex);
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_read_tcold() - reads sensor current tcold
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @tcold - resulting current tcold value
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_read_tcold(struct omap_bandgap *bg_ptr, int id,
+			       int *tcold)
+{
+	struct temp_sensor_registers *tsr;
+	u32 temp;
+	int ret;
+
+	ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	if (!OMAP_BANDGAP_HAS(bg_ptr, TALERT))
+		return -ENOTSUPP;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	temp = omap_bandgap_readl(bg_ptr, tsr->bgap_threshold);
+	temp = (temp & tsr->threshold_tcold_mask)
+	    >> __ffs(tsr->threshold_tcold_mask);
+	ret |= adc_to_temp_conversion(bg_ptr, id, temp, &temp);
+	if (ret)
+		return -EIO;
+
+	*tcold = temp;
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_write_tcold() - sets the sensor tcold
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @val - desired tcold value
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_write_tcold(struct omap_bandgap *bg_ptr, int id, int val)
+{
+	struct temp_sensor_data *ts_data;
+	struct temp_sensor_registers *tsr;
+	u32 t_cold;
+	int ret;
+
+	ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	if (!OMAP_BANDGAP_HAS(bg_ptr, TALERT))
+		return -ENOTSUPP;
+
+	ts_data = bg_ptr->conf->sensors[id].ts_data;
+	tsr = bg_ptr->conf->sensors[id].registers;
+	if (val > ts_data->max_temp + ts_data->hyst_val)
+		return -EINVAL;
+
+	ret = temp_to_adc_conversion(val, bg_ptr, id, &t_cold);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&bg_ptr->bg_mutex);
+	temp_sensor_configure_tcold(bg_ptr, id, t_cold);
+	mutex_unlock(&bg_ptr->bg_mutex);
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_read_update_interval() - read the sensor update interval
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @interval - resulting update interval in miliseconds
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_read_update_interval(struct omap_bandgap *bg_ptr, int id,
+					 int *interval)
+{
+	struct temp_sensor_registers *tsr;
+	u32 time;
+	int ret;
+
+	ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	if (!OMAP_BANDGAP_HAS(bg_ptr, COUNTER))
+		return -ENOTSUPP;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	time = omap_bandgap_readl(bg_ptr, tsr->bgap_counter);
+	if (ret)
+		return ret;
+	time = (time & tsr->counter_mask) >> __ffs(tsr->counter_mask);
+	time = time * 1000 / bg_ptr->clk_rate;
+
+	*interval = time;
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_write_update_interval() - set the update interval
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @interval - desired update interval in miliseconds
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_write_update_interval(struct omap_bandgap *bg_ptr,
+					  int id, u32 interval)
+{
+	int ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	if (!OMAP_BANDGAP_HAS(bg_ptr, COUNTER))
+		return -ENOTSUPP;
+
+	interval = interval * bg_ptr->clk_rate / 1000;
+	mutex_lock(&bg_ptr->bg_mutex);
+	configure_temp_sensor_counter(bg_ptr, id, interval);
+	mutex_unlock(&bg_ptr->bg_mutex);
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_read_temperature() - report current temperature
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @temperature - resulting temperature
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_read_temperature(struct omap_bandgap *bg_ptr, int id,
+				     int *temperature)
+{
+	struct temp_sensor_registers *tsr;
+	u32 temp;
+	int ret;
+
+	ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	temp = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+	temp &= tsr->bgap_dtemp_mask;
+
+	ret |= adc_to_temp_conversion(bg_ptr, id, temp, &temp);
+	if (ret)
+		return -EIO;
+
+	*temperature = temp;
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_set_sensor_data() - helper function to store thermal
+ * framework related data.
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ * @data - thermal framework related data to be stored
+ *
+ * returns 0 on success or the proper error code
+ */
+int omap_bandgap_set_sensor_data(struct omap_bandgap *bg_ptr, int id,
+				void *data)
+{
+	int ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ret;
+
+	bg_ptr->conf->sensors[id].data = data;
+
+	return 0;
+}
+
+/**
+ * omap_bandgap_get_sensor_data() - helper function to get thermal
+ * framework related data.
+ * @bg_ptr - pointer to bandgap instance
+ * @id - sensor id
+ *
+ * returns data stored by set function with sensor id on success or NULL
+ */
+void *omap_bandgap_get_sensor_data(struct omap_bandgap *bg_ptr, int id)
+{
+	int ret = omap_bandgap_validate(bg_ptr, id);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return bg_ptr->conf->sensors[id].data;
+}
+
+static int
+omap_bandgap_force_single_read(struct omap_bandgap *bg_ptr, int id)
+{
+	struct temp_sensor_registers *tsr;
+	u32 temp = 0, counter = 1000;
+
+	tsr = bg_ptr->conf->sensors[id].registers;
+	/* Select single conversion mode */
+	if (OMAP_BANDGAP_HAS(bg_ptr, MODE_CONFIG)) {
+		temp = omap_bandgap_readl(bg_ptr, tsr->bgap_mode_ctrl);
+		temp &= ~(1 << __ffs(tsr->mode_ctrl_mask));
+		omap_bandgap_writel(bg_ptr, temp, tsr->bgap_mode_ctrl);
+	}
+
+	/* Start of Conversion = 1 */
+	temp = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+	temp |= 1 << __ffs(tsr->bgap_soc_mask);
+	omap_bandgap_writel(bg_ptr, temp, tsr->temp_sensor_ctrl);
+	/* Wait until DTEMP is updated */
+	temp = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+	temp &= (tsr->bgap_dtemp_mask);
+	while ((temp == 0) && --counter) {
+		temp = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+		temp &= (tsr->bgap_dtemp_mask);
+	}
+	/* Start of Conversion = 0 */
+	temp = omap_bandgap_readl(bg_ptr, tsr->temp_sensor_ctrl);
+	temp &= ~(1 << __ffs(tsr->bgap_soc_mask));
+	omap_bandgap_writel(bg_ptr, temp, tsr->temp_sensor_ctrl);
+
+	return 0;
+}
+
+/**
+ * enable_continuous_mode() - One time enabling of continuous conversion mode
+ * @bg_ptr - pointer to scm instance
+ *
+ * Call this function only if HAS(MODE_CONFIG) is set
+ */
+static int enable_continuous_mode(struct omap_bandgap *bg_ptr)
+{
+	struct temp_sensor_registers *tsr;
+	int i;
+	u32 val;
+
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		/* Perform a single read just before enabling continuous */
+		omap_bandgap_force_single_read(bg_ptr, i);
+		tsr = bg_ptr->conf->sensors[i].registers;
+		val = omap_bandgap_readl(bg_ptr, tsr->bgap_mode_ctrl);
+		val |= 1 << __ffs(tsr->mode_ctrl_mask);
+		omap_bandgap_writel(bg_ptr, val, tsr->bgap_mode_ctrl);
+	}
+
+	return 0;
+}
+
+static int omap_bandgap_tshut_init(struct omap_bandgap *bg_ptr,
+				      struct platform_device *pdev)
+{
+	int gpio_nr = bg_ptr->tshut_gpio;
+	int status;
+
+	/* Request for gpio_86 line */
+	status = gpio_request(gpio_nr, "tshut");
+	if (status < 0) {
+		dev_err(bg_ptr->dev,
+			"Could not request for TSHUT GPIO:%i\n", 86);
+		return status;
+	}
+	status = gpio_direction_input(gpio_nr);
+	if (status) {
+		dev_err(bg_ptr->dev,
+			"Cannot set input TSHUT GPIO %d\n", gpio_nr);
+		return status;
+	}
+
+	status = request_irq(gpio_to_irq(gpio_nr),
+			     omap_bandgap_tshut_irq_handler,
+			     IRQF_TRIGGER_RISING, "tshut",
+			     NULL);
+	if (status) {
+		gpio_free(gpio_nr);
+		dev_err(bg_ptr->dev, "request irq failed for TSHUT");
+	}
+
+	return 0;
+}
+
+/* Initialization of Talert. Call it only if HAS(TALERT) is set */
+static int omap_bandgap_talert_init(struct omap_bandgap *bg_ptr,
+				       struct platform_device *pdev)
+{
+	int ret;
+
+	bg_ptr->irq = platform_get_irq(pdev, 0);
+	if (bg_ptr->irq < 0) {
+		dev_err(&pdev->dev, "get_irq failed\n");
+		return bg_ptr->irq;
+	}
+	ret = request_threaded_irq(bg_ptr->irq, NULL,
+				   talert_irq_handler,
+				   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+				   "talert", bg_ptr);
+	if (ret) {
+		dev_err(&pdev->dev, "Request threaded irq failed.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_omap_bandgap_match[];
+static struct omap_bandgap *omap_bandgap_build(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	const struct of_device_id *of_id;
+	struct omap_bandgap *bg_ptr;
+	struct resource *res;
+	u32 prop;
+	int i;
+
+	/* just for the sake */
+	if (!node) {
+		dev_err(&pdev->dev, "no platform information available\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	bg_ptr = devm_kzalloc(&pdev->dev, sizeof(struct omap_bandgap),
+				    GFP_KERNEL);
+	if (!bg_ptr) {
+		dev_err(&pdev->dev, "Unable to allocate mem for driver ref\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	of_id = of_match_device(of_omap_bandgap_match, &pdev->dev);
+	if (of_id)
+		bg_ptr->conf = of_id->data;
+
+	i = 0;
+	do {
+		void __iomem *chunk;
+
+		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+		if (!res)
+			break;
+		chunk = devm_request_and_ioremap(&pdev->dev, res);
+		if (i == 0)
+			bg_ptr->base = chunk;
+		if (!chunk) {
+			dev_err(&pdev->dev,
+				"failed to request the IO (%d:%pR).\n",
+				i, res);
+			return ERR_PTR(-EADDRNOTAVAIL);
+		}
+		i++;
+	} while (res);
+
+	if (OMAP_BANDGAP_HAS(bg_ptr, TSHUT)) {
+		if (of_property_read_u32(node, "ti,tshut-gpio", &prop) < 0) {
+			dev_err(&pdev->dev, "missing tshut gpio in device tree\n");
+			return ERR_PTR(-EINVAL);
+		}
+		bg_ptr->tshut_gpio = prop;
+		if (!gpio_is_valid(bg_ptr->tshut_gpio)) {
+			dev_err(&pdev->dev, "invalid gpio for tshut (%d)\n",
+				bg_ptr->tshut_gpio);
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	return bg_ptr;
+}
+
+static
+int __devinit omap_bandgap_probe(struct platform_device *pdev)
+{
+	struct omap_bandgap *bg_ptr;
+	int clk_rate, ret = 0, i;
+
+	bg_ptr = omap_bandgap_build(pdev);
+	if (IS_ERR_OR_NULL(bg_ptr)) {
+		dev_err(&pdev->dev, "failed to fetch platform data\n");
+		return PTR_ERR(bg_ptr);
+	}
+	bg_ptr->dev = &pdev->dev;
+
+	if (OMAP_BANDGAP_HAS(bg_ptr, TSHUT)) {
+		ret = omap_bandgap_tshut_init(bg_ptr, pdev);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"failed to initialize system tshut IRQ\n");
+			return ret;
+		}
+	}
+
+	bg_ptr->fclock = clk_get(NULL, bg_ptr->conf->fclock_name);
+	ret = IS_ERR_OR_NULL(bg_ptr->fclock);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request fclock reference\n");
+		goto free_irqs;
+	}
+
+	bg_ptr->div_clk = clk_get(NULL,  bg_ptr->conf->div_ck_name);
+	ret = IS_ERR_OR_NULL(bg_ptr->div_clk);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"failed to request div_ts_ck clock ref\n");
+		goto free_irqs;
+	}
+
+	bg_ptr->conv_table = bg_ptr->conf->conv_table;
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		struct temp_sensor_registers *tsr;
+		u32 val;
+
+		tsr = bg_ptr->conf->sensors[i].registers;
+		/*
+		 * check if the efuse has a non-zero value if not
+		 * it is an untrimmed sample and the temperatures
+		 * may not be accurate
+		 */
+		val = omap_bandgap_readl(bg_ptr, tsr->bgap_efuse);
+		if (ret || !val)
+			dev_info(&pdev->dev,
+				 "Non-trimmed BGAP, Temp not accurate\n");
+	}
+
+	clk_rate = clk_round_rate(bg_ptr->div_clk,
+				  bg_ptr->conf->sensors[0].ts_data->max_freq);
+	if (clk_rate < bg_ptr->conf->sensors[0].ts_data->min_freq ||
+	    clk_rate == 0xffffffff) {
+		ret = -ENODEV;
+		dev_err(&pdev->dev, "wrong clock rate (%d)\n", clk_rate);
+		goto put_clks;
+	}
+
+	ret = clk_set_rate(bg_ptr->div_clk, clk_rate);
+	if (ret)
+		dev_err(&pdev->dev, "Cannot re-set clock rate. Continuing\n");
+
+	bg_ptr->clk_rate = clk_rate;
+	clk_enable(bg_ptr->fclock);
+
+	mutex_init(&bg_ptr->bg_mutex);
+	bg_ptr->dev = &pdev->dev;
+	platform_set_drvdata(pdev, bg_ptr);
+
+	omap_bandgap_power(bg_ptr, true);
+
+	/* Set default counter to 1 for now */
+	if (OMAP_BANDGAP_HAS(bg_ptr, COUNTER))
+		for (i = 0; i < bg_ptr->conf->sensor_count; i++)
+			configure_temp_sensor_counter(bg_ptr, i, 1);
+
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		struct temp_sensor_data *ts_data;
+
+		ts_data = bg_ptr->conf->sensors[i].ts_data;
+
+		if (OMAP_BANDGAP_HAS(bg_ptr, TALERT))
+			temp_sensor_init_talert_thresholds(bg_ptr, i,
+							   ts_data->t_hot,
+							   ts_data->t_cold);
+		if (OMAP_BANDGAP_HAS(bg_ptr, TSHUT_CONFIG)) {
+			temp_sensor_configure_tshut_hot(bg_ptr, i,
+							ts_data->tshut_hot);
+			temp_sensor_configure_tshut_cold(bg_ptr, i,
+							 ts_data->tshut_cold);
+		}
+	}
+
+	if (OMAP_BANDGAP_HAS(bg_ptr, MODE_CONFIG))
+		enable_continuous_mode(bg_ptr);
+
+	/* Set .250 seconds time as default counter */
+	if (OMAP_BANDGAP_HAS(bg_ptr, COUNTER))
+		for (i = 0; i < bg_ptr->conf->sensor_count; i++)
+			configure_temp_sensor_counter(bg_ptr, i,
+						      bg_ptr->clk_rate / 4);
+
+	/* Every thing is good? Then expose the sensors */
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		char *domain;
+
+		domain = bg_ptr->conf->sensors[i].domain;
+		if (bg_ptr->conf->expose_sensor)
+			bg_ptr->conf->expose_sensor(bg_ptr, i, domain);
+
+		if (bg_ptr->conf->sensors[i].register_cooling)
+			bg_ptr->conf->sensors[i].register_cooling(bg_ptr, i);
+	}
+
+	/*
+	 * Enable the Interrupts once everything is set. Otherwise irq handler
+	 * might be called as soon as it is enabled where as rest of framework
+	 * is still getting initialised.
+	 */
+	if (OMAP_BANDGAP_HAS(bg_ptr, TALERT)) {
+		ret = omap_bandgap_talert_init(bg_ptr, pdev);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to initialize Talert IRQ\n");
+			i = bg_ptr->conf->sensor_count;
+			goto disable_clk;
+		}
+	}
+
+	return 0;
+
+disable_clk:
+	clk_disable(bg_ptr->fclock);
+put_clks:
+	clk_put(bg_ptr->fclock);
+	clk_put(bg_ptr->div_clk);
+free_irqs:
+	if (OMAP_BANDGAP_HAS(bg_ptr, TSHUT)) {
+		free_irq(gpio_to_irq(bg_ptr->tshut_gpio), NULL);
+		gpio_free(bg_ptr->tshut_gpio);
+	}
+
+	return ret;
+}
+
+static
+int __devexit omap_bandgap_remove(struct platform_device *pdev)
+{
+	struct omap_bandgap *bg_ptr = platform_get_drvdata(pdev);
+	int i;
+
+	/* First thing is to remove sensor interfaces */
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		if (bg_ptr->conf->sensors[i].register_cooling)
+			bg_ptr->conf->sensors[i].unregister_cooling(bg_ptr, i);
+
+		if (bg_ptr->conf->remove_sensor)
+			bg_ptr->conf->remove_sensor(bg_ptr, i);
+	}
+
+	omap_bandgap_power(bg_ptr, false);
+
+	clk_disable(bg_ptr->fclock);
+	clk_put(bg_ptr->fclock);
+	clk_put(bg_ptr->div_clk);
+
+	if (OMAP_BANDGAP_HAS(bg_ptr, TALERT))
+		free_irq(bg_ptr->irq, bg_ptr);
+
+	if (OMAP_BANDGAP_HAS(bg_ptr, TSHUT)) {
+		free_irq(gpio_to_irq(bg_ptr->tshut_gpio), NULL);
+		gpio_free(bg_ptr->tshut_gpio);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int omap_bandgap_save_ctxt(struct omap_bandgap *bg_ptr)
+{
+	int i;
+
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		struct temp_sensor_registers *tsr;
+		struct temp_sensor_regval *rval;
+
+		rval = &bg_ptr->conf->sensors[i].regval;
+		tsr = bg_ptr->conf->sensors[i].registers;
+
+		if (OMAP_BANDGAP_HAS(bg_ptr, MODE_CONFIG))
+			rval->bg_mode_ctrl = omap_bandgap_readl(bg_ptr,
+								tsr->bgap_mode_ctrl);
+		if (OMAP_BANDGAP_HAS(bg_ptr, COUNTER))
+			rval->bg_counter = omap_bandgap_readl(bg_ptr,
+							      tsr->bgap_counter);
+		if (OMAP_BANDGAP_HAS(bg_ptr, TALERT)) {
+			rval->bg_threshold = omap_bandgap_readl(bg_ptr,
+								tsr->bgap_threshold);
+			rval->bg_ctrl = omap_bandgap_readl(bg_ptr,
+							   tsr->bgap_mask_ctrl);
+		}
+
+		if (OMAP_BANDGAP_HAS(bg_ptr, TSHUT_CONFIG))
+			rval->tshut_threshold = omap_bandgap_readl(bg_ptr,
+								   tsr->tshut_threshold);
+	}
+
+	return 0;
+}
+
+static int omap_bandgap_restore_ctxt(struct omap_bandgap *bg_ptr)
+{
+	int i;
+	u32 temp = 0;
+
+	for (i = 0; i < bg_ptr->conf->sensor_count; i++) {
+		struct temp_sensor_registers *tsr;
+		struct temp_sensor_regval *rval;
+		u32 val = 0;
+
+		rval = &bg_ptr->conf->sensors[i].regval;
+		tsr = bg_ptr->conf->sensors[i].registers;
+
+		if (OMAP_BANDGAP_HAS(bg_ptr, COUNTER))
+			val = omap_bandgap_readl(bg_ptr, tsr->bgap_counter);
+
+		if (val == 0) {
+			if (OMAP_BANDGAP_HAS(bg_ptr, TSHUT_CONFIG))
+				omap_bandgap_writel(bg_ptr, rval->tshut_threshold,
+							   tsr->tshut_threshold);
+			/* Force immediate temperature measurement and update
+			 * of the DTEMP field
+			 */
+			omap_bandgap_force_single_read(bg_ptr, i);
+
+			if (OMAP_BANDGAP_HAS(bg_ptr, COUNTER))
+				omap_bandgap_writel(bg_ptr, rval->bg_counter,
+							   tsr->bgap_counter);
+			if (OMAP_BANDGAP_HAS(bg_ptr, MODE_CONFIG))
+				omap_bandgap_writel(bg_ptr, rval->bg_mode_ctrl,
+							   tsr->bgap_mode_ctrl);
+			if (OMAP_BANDGAP_HAS(bg_ptr, TALERT)) {
+				omap_bandgap_writel(bg_ptr,
+							   rval->bg_threshold,
+							   tsr->bgap_threshold);
+				omap_bandgap_writel(bg_ptr, rval->bg_ctrl,
+							   tsr->bgap_mask_ctrl);
+			}
+		} else {
+			temp = omap_bandgap_readl(bg_ptr,
+						  tsr->temp_sensor_ctrl);
+			temp &= (tsr->bgap_dtemp_mask);
+			omap_bandgap_force_single_read(bg_ptr, i);
+			if (temp == 0 && OMAP_BANDGAP_HAS(bg_ptr, TALERT)) {
+				temp = omap_bandgap_readl(bg_ptr,
+							  tsr->bgap_mask_ctrl);
+				temp |= 1 << __ffs(tsr->mode_ctrl_mask);
+				omap_bandgap_writel(bg_ptr, temp,
+							   tsr->bgap_mask_ctrl);
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int omap_bandgap_suspend(struct device *dev)
+{
+	struct omap_bandgap *bg_ptr = dev_get_drvdata(dev);
+	int err;
+
+	err = omap_bandgap_save_ctxt(bg_ptr);
+	omap_bandgap_power(bg_ptr, false);
+	clk_disable(bg_ptr->fclock);
+
+	return err;
+}
+
+static int omap_bandgap_resume(struct device *dev)
+{
+	struct omap_bandgap *bg_ptr = dev_get_drvdata(dev);
+
+	clk_enable(bg_ptr->fclock);
+	omap_bandgap_power(bg_ptr, true);
+
+	return omap_bandgap_restore_ctxt(bg_ptr);
+}
+static const struct dev_pm_ops omap_bandgap_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(omap_bandgap_suspend,
+				omap_bandgap_resume)
+};
+
+#define DEV_PM_OPS	(&omap_bandgap_dev_pm_ops)
+#else
+#define DEV_PM_OPS	NULL
+#endif
+
+static const struct of_device_id of_omap_bandgap_match[] = {
+	/* Sentinel */
+	{ },
+};
+MODULE_DEVICE_TABLE(of, of_omap_bandgap_match);
+
+static struct platform_driver omap_bandgap_sensor_driver = {
+	.probe = omap_bandgap_probe,
+	.remove = omap_bandgap_remove,
+	.driver = {
+			.name = "omap-bandgap",
+			.pm = DEV_PM_OPS,
+			.of_match_table	= of_omap_bandgap_match,
+	},
+};
+
+module_platform_driver(omap_bandgap_sensor_driver);
+
+MODULE_DESCRIPTION("OMAP4+ bandgap temperature sensor driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:omap-bandgap");
+MODULE_AUTHOR("Texas Instrument Inc.");