omap-bandgap.c

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/*
 * OMAP4 Bandgap temperature sensor driver
 *
 * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
 * Author: J Keerthy <[email protected]>
 * Author: Moiz Sonasath <[email protected]>
 * Couple of fixes, DT and MFD adaptation:
 *   Eduardo Valentin <[email protected]>
 *
 * 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[low] || 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 */
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;
}

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;
}

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;
}

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;
}

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;
}

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;
}

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;
}

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;
}

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;
}

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;

        if (bg_ptr->conf->sensors[i].register_cooling)
            bg_ptr->conf->sensors[i].register_cooling(bg_ptr, i);

        domain = bg_ptr->conf->sensors[i].domain;
        if (bg_ptr->conf->expose_sensor)
            bg_ptr->conf->expose_sensor(bg_ptr, i, domain);
    }

    /*
     * 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[] = {
#ifdef CONFIG_OMAP4_THERMAL
    {
        .compatible = "ti,omap4430-bandgap",
        .data = (void *)&omap4430_data,
    },
    {
        .compatible = "ti,omap4460-bandgap",
        .data = (void *)&omap4460_data,
    },
    {
        .compatible = "ti,omap4470-bandgap",
        .data = (void *)&omap4470_data,
    },
#endif
#ifdef CONFIG_OMAP5_THERMAL
    {
        .compatible = "ti,omap5430-bandgap",
        .data = (void *)&omap5430_data,
    },
#endif
    /* 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.");