572 lines
14 KiB
C
572 lines
14 KiB
C
/*
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* intel_mid_thermal.c - Intel MID platform thermal driver
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*
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* Copyright (C) 2011 Intel Corporation
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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* Author: Durgadoss R <durgadoss.r@intel.com>
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*/
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#define pr_fmt(fmt) "intel_mid_thermal: " fmt
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/err.h>
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#include <linux/param.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/pm.h>
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#include <linux/thermal.h>
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#include <linux/mfd/intel_msic.h>
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/* Number of thermal sensors */
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#define MSIC_THERMAL_SENSORS 4
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/* ADC1 - thermal registers */
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#define MSIC_ADC_ENBL 0x10
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#define MSIC_ADC_START 0x08
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#define MSIC_ADCTHERM_ENBL 0x04
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#define MSIC_ADCRRDATA_ENBL 0x05
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#define MSIC_CHANL_MASK_VAL 0x0F
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#define MSIC_STOPBIT_MASK 16
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#define MSIC_ADCTHERM_MASK 4
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/* Number of ADC channels */
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#define ADC_CHANLS_MAX 15
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#define ADC_LOOP_MAX (ADC_CHANLS_MAX - MSIC_THERMAL_SENSORS)
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/* ADC channel code values */
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#define SKIN_SENSOR0_CODE 0x08
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#define SKIN_SENSOR1_CODE 0x09
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#define SYS_SENSOR_CODE 0x0A
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#define MSIC_DIE_SENSOR_CODE 0x03
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#define SKIN_THERM_SENSOR0 0
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#define SKIN_THERM_SENSOR1 1
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#define SYS_THERM_SENSOR2 2
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#define MSIC_DIE_THERM_SENSOR3 3
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/* ADC code range */
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#define ADC_MAX 977
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#define ADC_MIN 162
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#define ADC_VAL0C 887
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#define ADC_VAL20C 720
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#define ADC_VAL40C 508
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#define ADC_VAL60C 315
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/* ADC base addresses */
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#define ADC_CHNL_START_ADDR INTEL_MSIC_ADC1ADDR0 /* increments by 1 */
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#define ADC_DATA_START_ADDR INTEL_MSIC_ADC1SNS0H /* increments by 2 */
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/* MSIC die attributes */
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#define MSIC_DIE_ADC_MIN 488
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#define MSIC_DIE_ADC_MAX 1004
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/* This holds the address of the first free ADC channel,
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* among the 15 channels
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*/
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static int channel_index;
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struct platform_info {
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struct platform_device *pdev;
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struct thermal_zone_device *tzd[MSIC_THERMAL_SENSORS];
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};
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struct thermal_device_info {
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unsigned int chnl_addr;
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int direct;
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/* This holds the current temperature in millidegree celsius */
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long curr_temp;
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};
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/**
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* to_msic_die_temp - converts adc_val to msic_die temperature
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* @adc_val: ADC value to be converted
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*
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* Can sleep
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*/
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static int to_msic_die_temp(uint16_t adc_val)
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{
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return (368 * (adc_val) / 1000) - 220;
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}
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/**
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* is_valid_adc - checks whether the adc code is within the defined range
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* @min: minimum value for the sensor
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* @max: maximum value for the sensor
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*
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* Can sleep
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*/
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static int is_valid_adc(uint16_t adc_val, uint16_t min, uint16_t max)
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{
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return (adc_val >= min) && (adc_val <= max);
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}
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/**
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* adc_to_temp - converts the ADC code to temperature in C
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* @direct: true if ths channel is direct index
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* @adc_val: the adc_val that needs to be converted
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* @tp: temperature return value
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*
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* Linear approximation is used to covert the skin adc value into temperature.
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* This technique is used to avoid very long look-up table to get
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* the appropriate temp value from ADC value.
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* The adc code vs sensor temp curve is split into five parts
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* to achieve very close approximate temp value with less than
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* 0.5C error
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*/
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static int adc_to_temp(int direct, uint16_t adc_val, int *tp)
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{
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int temp;
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/* Direct conversion for die temperature */
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if (direct) {
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if (is_valid_adc(adc_val, MSIC_DIE_ADC_MIN, MSIC_DIE_ADC_MAX)) {
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*tp = to_msic_die_temp(adc_val) * 1000;
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return 0;
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}
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return -ERANGE;
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}
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if (!is_valid_adc(adc_val, ADC_MIN, ADC_MAX))
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return -ERANGE;
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/* Linear approximation for skin temperature */
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if (adc_val > ADC_VAL0C)
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temp = 177 - (adc_val/5);
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else if ((adc_val <= ADC_VAL0C) && (adc_val > ADC_VAL20C))
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temp = 111 - (adc_val/8);
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else if ((adc_val <= ADC_VAL20C) && (adc_val > ADC_VAL40C))
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temp = 92 - (adc_val/10);
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else if ((adc_val <= ADC_VAL40C) && (adc_val > ADC_VAL60C))
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temp = 91 - (adc_val/10);
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else
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temp = 112 - (adc_val/6);
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/* Convert temperature in celsius to milli degree celsius */
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*tp = temp * 1000;
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return 0;
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}
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/**
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* mid_read_temp - read sensors for temperature
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* @temp: holds the current temperature for the sensor after reading
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*
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* reads the adc_code from the channel and converts it to real
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* temperature. The converted value is stored in temp.
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*
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* Can sleep
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*/
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static int mid_read_temp(struct thermal_zone_device *tzd, int *temp)
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{
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struct thermal_device_info *td_info = tzd->devdata;
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uint16_t adc_val, addr;
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uint8_t data = 0;
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int ret;
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int curr_temp;
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addr = td_info->chnl_addr;
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/* Enable the msic for conversion before reading */
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ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
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if (ret)
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return ret;
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/* Re-toggle the RRDATARD bit (temporary workaround) */
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ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
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if (ret)
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return ret;
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/* Read the higher bits of data */
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ret = intel_msic_reg_read(addr, &data);
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if (ret)
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return ret;
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/* Shift bits to accommodate the lower two data bits */
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adc_val = (data << 2);
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addr++;
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ret = intel_msic_reg_read(addr, &data);/* Read lower bits */
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if (ret)
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return ret;
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/* Adding lower two bits to the higher bits */
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data &= 03;
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adc_val += data;
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/* Convert ADC value to temperature */
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ret = adc_to_temp(td_info->direct, adc_val, &curr_temp);
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if (ret == 0)
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*temp = td_info->curr_temp = curr_temp;
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return ret;
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}
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/**
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* configure_adc - enables/disables the ADC for conversion
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* @val: zero: disables the ADC non-zero:enables the ADC
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*
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* Enable/Disable the ADC depending on the argument
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*
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* Can sleep
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*/
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static int configure_adc(int val)
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{
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int ret;
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uint8_t data;
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ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
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if (ret)
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return ret;
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if (val) {
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/* Enable and start the ADC */
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data |= (MSIC_ADC_ENBL | MSIC_ADC_START);
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} else {
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/* Just stop the ADC */
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data &= (~MSIC_ADC_START);
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}
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return intel_msic_reg_write(INTEL_MSIC_ADC1CNTL1, data);
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}
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/**
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* set_up_therm_channel - enable thermal channel for conversion
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* @base_addr: index of free msic ADC channel
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*
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* Enable all the three channels for conversion
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*
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* Can sleep
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*/
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static int set_up_therm_channel(u16 base_addr)
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{
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int ret;
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/* Enable all the sensor channels */
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ret = intel_msic_reg_write(base_addr, SKIN_SENSOR0_CODE);
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if (ret)
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return ret;
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ret = intel_msic_reg_write(base_addr + 1, SKIN_SENSOR1_CODE);
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if (ret)
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return ret;
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ret = intel_msic_reg_write(base_addr + 2, SYS_SENSOR_CODE);
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if (ret)
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return ret;
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/* Since this is the last channel, set the stop bit
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* to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
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ret = intel_msic_reg_write(base_addr + 3,
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(MSIC_DIE_SENSOR_CODE | 0x10));
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if (ret)
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return ret;
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/* Enable ADC and start it */
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return configure_adc(1);
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}
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/**
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* reset_stopbit - sets the stop bit to 0 on the given channel
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* @addr: address of the channel
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*
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* Can sleep
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*/
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static int reset_stopbit(uint16_t addr)
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{
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int ret;
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uint8_t data;
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ret = intel_msic_reg_read(addr, &data);
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if (ret)
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return ret;
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/* Set the stop bit to zero */
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return intel_msic_reg_write(addr, (data & 0xEF));
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}
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/**
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* find_free_channel - finds an empty channel for conversion
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*
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* If the ADC is not enabled then start using 0th channel
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* itself. Otherwise find an empty channel by looking for a
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* channel in which the stopbit is set to 1. returns the index
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* of the first free channel if succeeds or an error code.
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*
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* Context: can sleep
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*
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* FIXME: Ultimately the channel allocator will move into the intel_scu_ipc
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* code.
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*/
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static int find_free_channel(void)
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{
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int ret;
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int i;
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uint8_t data;
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/* check whether ADC is enabled */
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ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
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if (ret)
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return ret;
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if ((data & MSIC_ADC_ENBL) == 0)
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return 0;
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/* ADC is already enabled; Looking for an empty channel */
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for (i = 0; i < ADC_CHANLS_MAX; i++) {
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ret = intel_msic_reg_read(ADC_CHNL_START_ADDR + i, &data);
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if (ret)
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return ret;
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if (data & MSIC_STOPBIT_MASK) {
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ret = i;
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break;
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}
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}
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return (ret > ADC_LOOP_MAX) ? (-EINVAL) : ret;
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}
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/**
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* mid_initialize_adc - initializing the ADC
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* @dev: our device structure
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*
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* Initialize the ADC for reading thermistor values. Can sleep.
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*/
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static int mid_initialize_adc(struct device *dev)
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{
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u8 data;
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u16 base_addr;
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int ret;
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/*
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* Ensure that adctherm is disabled before we
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* initialize the ADC
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*/
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ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL3, &data);
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if (ret)
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return ret;
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data &= ~MSIC_ADCTHERM_MASK;
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ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, data);
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if (ret)
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return ret;
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/* Index of the first channel in which the stop bit is set */
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channel_index = find_free_channel();
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if (channel_index < 0) {
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dev_err(dev, "No free ADC channels");
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return channel_index;
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}
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base_addr = ADC_CHNL_START_ADDR + channel_index;
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if (!(channel_index == 0 || channel_index == ADC_LOOP_MAX)) {
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/* Reset stop bit for channels other than 0 and 12 */
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ret = reset_stopbit(base_addr);
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if (ret)
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return ret;
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/* Index of the first free channel */
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base_addr++;
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channel_index++;
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}
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ret = set_up_therm_channel(base_addr);
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if (ret) {
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dev_err(dev, "unable to enable ADC");
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return ret;
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}
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dev_dbg(dev, "ADC initialization successful");
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return ret;
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}
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/**
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* initialize_sensor - sets default temp and timer ranges
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* @index: index of the sensor
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*
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* Context: can sleep
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*/
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static struct thermal_device_info *initialize_sensor(int index)
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{
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struct thermal_device_info *td_info =
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kzalloc(sizeof(struct thermal_device_info), GFP_KERNEL);
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if (!td_info)
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return NULL;
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/* Set the base addr of the channel for this sensor */
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td_info->chnl_addr = ADC_DATA_START_ADDR + 2 * (channel_index + index);
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/* Sensor 3 is direct conversion */
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if (index == 3)
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td_info->direct = 1;
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return td_info;
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}
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#ifdef CONFIG_PM_SLEEP
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/**
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* mid_thermal_resume - resume routine
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* @dev: device structure
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*
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* mid thermal resume: re-initializes the adc. Can sleep.
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*/
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static int mid_thermal_resume(struct device *dev)
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{
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return mid_initialize_adc(dev);
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}
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/**
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* mid_thermal_suspend - suspend routine
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* @dev: device structure
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*
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* mid thermal suspend implements the suspend functionality
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* by stopping the ADC. Can sleep.
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*/
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static int mid_thermal_suspend(struct device *dev)
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{
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/*
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* This just stops the ADC and does not disable it.
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* temporary workaround until we have a generic ADC driver.
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* If 0 is passed, it disables the ADC.
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*/
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return configure_adc(0);
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}
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#endif
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static SIMPLE_DEV_PM_OPS(mid_thermal_pm,
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mid_thermal_suspend, mid_thermal_resume);
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/**
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* read_curr_temp - reads the current temperature and stores in temp
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* @temp: holds the current temperature value after reading
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*
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* Can sleep
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*/
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static int read_curr_temp(struct thermal_zone_device *tzd, int *temp)
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{
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WARN_ON(tzd == NULL);
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return mid_read_temp(tzd, temp);
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}
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/* Can't be const */
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static struct thermal_zone_device_ops tzd_ops = {
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.get_temp = read_curr_temp,
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};
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/**
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* mid_thermal_probe - mfld thermal initialize
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* @pdev: platform device structure
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*
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* mid thermal probe initializes the hardware and registers
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* all the sensors with the generic thermal framework. Can sleep.
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*/
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static int mid_thermal_probe(struct platform_device *pdev)
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{
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static char *name[MSIC_THERMAL_SENSORS] = {
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"skin0", "skin1", "sys", "msicdie"
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};
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int ret;
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int i;
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struct platform_info *pinfo;
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pinfo = devm_kzalloc(&pdev->dev, sizeof(struct platform_info),
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GFP_KERNEL);
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if (!pinfo)
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return -ENOMEM;
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/* Initializing the hardware */
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ret = mid_initialize_adc(&pdev->dev);
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if (ret) {
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dev_err(&pdev->dev, "ADC init failed");
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return ret;
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}
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/* Register each sensor with the generic thermal framework*/
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for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
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struct thermal_device_info *td_info = initialize_sensor(i);
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if (!td_info) {
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ret = -ENOMEM;
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goto err;
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}
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pinfo->tzd[i] = thermal_zone_device_register(name[i],
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0, 0, td_info, &tzd_ops, NULL, 0, 0);
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if (IS_ERR(pinfo->tzd[i])) {
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kfree(td_info);
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ret = PTR_ERR(pinfo->tzd[i]);
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goto err;
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}
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}
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pinfo->pdev = pdev;
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platform_set_drvdata(pdev, pinfo);
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return 0;
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err:
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while (--i >= 0) {
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kfree(pinfo->tzd[i]->devdata);
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thermal_zone_device_unregister(pinfo->tzd[i]);
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}
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configure_adc(0);
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return ret;
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}
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/**
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* mid_thermal_remove - mfld thermal finalize
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* @dev: platform device structure
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*
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* MLFD thermal remove unregisters all the sensors from the generic
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* thermal framework. Can sleep.
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*/
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static int mid_thermal_remove(struct platform_device *pdev)
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{
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int i;
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struct platform_info *pinfo = platform_get_drvdata(pdev);
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for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
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kfree(pinfo->tzd[i]->devdata);
|
|
thermal_zone_device_unregister(pinfo->tzd[i]);
|
|
}
|
|
|
|
/* Stop the ADC */
|
|
return configure_adc(0);
|
|
}
|
|
|
|
#define DRIVER_NAME "msic_thermal"
|
|
|
|
static const struct platform_device_id therm_id_table[] = {
|
|
{ DRIVER_NAME, 1 },
|
|
{ "msic_thermal", 1 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(platform, therm_id_table);
|
|
|
|
static struct platform_driver mid_thermal_driver = {
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
.pm = &mid_thermal_pm,
|
|
},
|
|
.probe = mid_thermal_probe,
|
|
.remove = mid_thermal_remove,
|
|
.id_table = therm_id_table,
|
|
};
|
|
|
|
module_platform_driver(mid_thermal_driver);
|
|
|
|
MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
|
|
MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
|
|
MODULE_LICENSE("GPL");
|