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* OMAP4 Bandgap temperature sensor driver
* Copyright (C) 2011 Texas Instruments Incorporated -
* Contact:
* Eduardo Valentin <>
* 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
* 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
#ifndef __TI_BANDGAP_H
#define __TI_BANDGAP_H
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/err.h>
* DOC: bandgap driver data structure
* ==================================
* +----------+----------------+
* | struct temp_sensor_regval |
* +---------------------------+
* * (Array of)
* |
* |
* +-------------------+ +-----------------+
* | struct ti_bandgap |-->| struct device * |
* +----------+--------+ +-----------------+
* |
* |
* V
* +------------------------+
* | struct ti_bandgap_data |
* +------------------------+
* |
* |
* * (Array of)
* +------------+------------------------------------------------------+
* | +----------+------------+ +-------------------------+ |
* | | struct ti_temp_sensor |-->| struct temp_sensor_data | |
* | +-----------------------+ +------------+------------+ |
* | | |
* | + |
* | V |
* | +----------+-------------------+ |
* | | struct temp_sensor_registers | |
* | +------------------------------+ |
* | |
* +-------------------------------------------------------------------+
* Above is a simple diagram describing how the data structure below
* are organized. For each bandgap device there should be a ti_bandgap_data
* containing the device instance configuration, as well as, an array of
* sensors, representing every sensor instance present in this bandgap.
* struct temp_sensor_registers - descriptor to access registers and bitfields
* @temp_sensor_ctrl: TEMP_SENSOR_CTRL register offset
* @bgap_tempsoff_mask: mask to temp_sensor_ctrl.tempsoff
* @bgap_soc_mask: mask to temp_sensor_ctrl.soc
* @bgap_eocz_mask: mask to temp_sensor_ctrl.eocz
* @bgap_dtemp_mask: mask to temp_sensor_ctrl.dtemp
* @bgap_mask_ctrl: BANDGAP_MASK_CTRL register offset
* @mask_hot_mask: mask to bandgap_mask_ctrl.mask_hot
* @mask_cold_mask: mask to bandgap_mask_ctrl.mask_cold
* @mask_counter_delay_mask: mask to bandgap_mask_ctrl.mask_counter_delay
* @mask_freeze_mask: mask to bandgap_mask_ctrl.mask_free
* @bgap_mode_ctrl: BANDGAP_MODE_CTRL register offset
* @mode_ctrl_mask: mask to bandgap_mode_ctrl.mode_ctrl
* @bgap_counter: BANDGAP_COUNTER register offset
* @counter_mask: mask to bandgap_counter.counter
* @bgap_threshold: BANDGAP_THRESHOLD register offset (TALERT thresholds)
* @threshold_thot_mask: mask to bandgap_threhold.thot
* @threshold_tcold_mask: mask to bandgap_threhold.tcold
* @tshut_threshold: TSHUT_THRESHOLD register offset (TSHUT thresholds)
* @tshut_hot_mask: mask to tshut_threhold.thot
* @tshut_cold_mask: mask to tshut_threhold.thot
* @bgap_status: BANDGAP_STATUS register offset
* @status_hot_mask: mask to
* @status_cold_mask: mask to bandgap_status.cold
* @ctrl_dtemp_1: CTRL_DTEMP1 register offset
* @ctrl_dtemp_2: CTRL_DTEMP2 register offset
* @bgap_efuse: BANDGAP_EFUSE register offset
* The register offsets and bitfields might change across
* OMAP and variants versions. Hence this struct serves as a
* descriptor map on how to access the registers and the bitfields.
* This descriptor contains registers of all versions of bandgap chips.
* Not all versions will use all registers, depending on the available
* features. Please read TRMs for descriptive explanation on each bitfield.
struct temp_sensor_registers {
u32 temp_sensor_ctrl;
u32 bgap_tempsoff_mask;
u32 bgap_soc_mask;
u32 bgap_eocz_mask;
u32 bgap_dtemp_mask;
u32 bgap_mask_ctrl;
u32 mask_hot_mask;
u32 mask_cold_mask;
u32 mask_counter_delay_mask;
u32 mask_freeze_mask;
u32 bgap_mode_ctrl;
u32 mode_ctrl_mask;
u32 bgap_counter;
u32 counter_mask;
u32 bgap_threshold;
u32 threshold_thot_mask;
u32 threshold_tcold_mask;
u32 tshut_threshold;
u32 tshut_hot_mask;
u32 tshut_cold_mask;
u32 bgap_status;
u32 status_hot_mask;
u32 status_cold_mask;
u32 ctrl_dtemp_1;
u32 ctrl_dtemp_2;
u32 bgap_efuse;
* struct temp_sensor_data - The thresholds and limits for temperature sensors.
* @tshut_hot: temperature to trigger a thermal reset (initial value)
* @tshut_cold: temp to get the plat out of reset due to thermal (init val)
* @t_hot: temperature to trigger a thermal alert (high initial value)
* @t_cold: temperature to trigger a thermal alert (low initial value)
* @min_freq: sensor minimum clock rate
* @max_freq: sensor maximum clock rate
* This data structure will hold the required thresholds and temperature limits
* for a specific temperature sensor, like shutdown temperature, alert
* temperature, clock / rate used, ADC conversion limits and update intervals
struct temp_sensor_data {
u32 tshut_hot;
u32 tshut_cold;
u32 t_hot;
u32 t_cold;
u32 min_freq;
u32 max_freq;
struct ti_bandgap_data;
* struct temp_sensor_regval - temperature sensor register values and priv data
* @bg_mode_ctrl: temp sensor control register value
* @bg_ctrl: bandgap ctrl register value
* @bg_counter: bandgap counter value
* @bg_threshold: bandgap threshold register value
* @tshut_threshold: bandgap tshut register value
* @data: private data
* Data structure to save and restore bandgap register set context. Only
* required registers are shadowed, when needed.
struct temp_sensor_regval {
u32 bg_mode_ctrl;
u32 bg_ctrl;
u32 bg_counter;
u32 bg_threshold;
u32 tshut_threshold;
void *data;
* struct ti_bandgap - bandgap device structure
* @dev: struct device pointer
* @base: io memory base address
* @conf: struct with bandgap configuration set (# sensors, conv_table, etc)
* @regval: temperature sensor register values
* @fclock: pointer to functional clock of temperature sensor
* @div_clk: pointer to divider clock of temperature sensor fclk
* @lock: spinlock for ti_bandgap structure
* @irq: MPU IRQ number for thermal alert
* @tshut_gpio: GPIO where Tshut signal is routed
* @clk_rate: Holds current clock rate
* The bandgap device structure representing the bandgap device instance.
* It holds most of the dynamic stuff. Configurations and sensor specific
* entries are inside the @conf structure.
struct ti_bandgap {
struct device *dev;
void __iomem *base;
const struct ti_bandgap_data *conf;
struct temp_sensor_regval *regval;
struct clk *fclock;
struct clk *div_clk;
spinlock_t lock; /* shields this struct */
int irq;
int tshut_gpio;
u32 clk_rate;
* struct ti_temp_sensor - bandgap temperature sensor configuration data
* @ts_data: pointer to struct with thresholds, limits of temperature sensor
* @registers: pointer to the list of register offsets and bitfields
* @domain: the name of the domain where the sensor is located
* @slope_pcb: sensor gradient slope info for hotspot extrapolation equation
* with no external influence
* @constant_pcb: sensor gradient const info for hotspot extrapolation equation
* with no external influence
* @register_cooling: function to describe how this sensor is going to be cooled
* @unregister_cooling: function to release cooling data
* Data structure to describe a temperature sensor handled by a bandgap device.
* It should provide configuration details on this sensor, such as how to
* access the registers affecting this sensor, shadow register buffer, how to
* assess the gradient from hotspot, how to cooldown the domain when sensor
* reports too hot temperature.
struct ti_temp_sensor {
struct temp_sensor_data *ts_data;
struct temp_sensor_registers *registers;
char *domain;
/* for hotspot extrapolation */
const int slope_pcb;
const int constant_pcb;
int (*register_cooling)(struct ti_bandgap *bgp, int id);
int (*unregister_cooling)(struct ti_bandgap *bgp, int id);
* DOC: ti bandgap feature types
* TI_BANDGAP_FEATURE_TSHUT - used when the thermal shutdown signal output
* of a bandgap device instance is routed to the processor. This means
* the system must react and perform the shutdown by itself (handle an
* IRQ, for instance).
* TI_BANDGAP_FEATURE_TSHUT_CONFIG - used when the bandgap device has control
* over the thermal shutdown configuration. This means that the thermal
* shutdown thresholds are programmable, for instance.
* TI_BANDGAP_FEATURE_TALERT - used when the bandgap device instance outputs
* a signal representing violation of programmable alert thresholds.
* TI_BANDGAP_FEATURE_MODE_CONFIG - used when it is possible to choose which
* mode, continuous or one shot, the bandgap device instance will operate.
* TI_BANDGAP_FEATURE_COUNTER - used when the bandgap device instance allows
* programming the update interval of its internal state machine.
* TI_BANDGAP_FEATURE_POWER_SWITCH - used when the bandgap device allows
* itself to be switched on/off.
* TI_BANDGAP_FEATURE_CLK_CTRL - used when the clocks feeding the bandgap
* device are gateable or not.
* TI_BANDGAP_FEATURE_FREEZE_BIT - used when the bandgap device features
* a history buffer that its update can be freezed/unfreezed.
* TI_BANDGAP_FEATURE_COUNTER_DELAY - used when the bandgap device features
* a delay programming based on distinct values.
* TI_BANDGAP_FEATURE_HISTORY_BUFFER - used when the bandgap device features
* a history buffer of temperatures.
* TI_BANDGAP_FEATURE_ERRATA_814 - used to workaorund when the bandgap device
* has Errata 814
* TI_BANDGAP_FEATURE_UNRELIABLE - used when the sensor readings are too
* inaccurate.
* TI_BANDGAP_HAS(b, f) - macro to check if a bandgap device is capable of a
* specific feature (above) or not. Return non-zero, if yes.
#define TI_BANDGAP_HAS(b, f) \
((b)->conf->features & TI_BANDGAP_FEATURE_ ## f)
* struct ti_bandgap_data - ti bandgap data configuration structure
* @features: a bitwise flag set to describe the device features
* @conv_table: Pointer to ADC to temperature conversion table
* @adc_start_val: ADC conversion table starting value
* @adc_end_val: ADC conversion table ending value
* @fclock_name: clock name of the functional clock
* @div_ck_name: clock name of the clock divisor
* @sensor_count: count of temperature sensor within this bandgap device
* @report_temperature: callback to report thermal alert to thermal API
* @expose_sensor: callback to export sensor to thermal API
* @remove_sensor: callback to destroy sensor from thermal API
* @sensors: array of sensors present in this bandgap instance
* This is a data structure which should hold most of the static configuration
* of a bandgap device instance. It should describe which features this instance
* is capable of, the clock names to feed this device, the amount of sensors and
* their configuration representation, and how to export and unexport them to
* a thermal API.
struct ti_bandgap_data {
unsigned int features;
const int *conv_table;
u32 adc_start_val;
u32 adc_end_val;
char *fclock_name;
char *div_ck_name;
int sensor_count;
int (*report_temperature)(struct ti_bandgap *bgp, int id);
int (*expose_sensor)(struct ti_bandgap *bgp, int id, char *domain);
int (*remove_sensor)(struct ti_bandgap *bgp, int id);
/* this needs to be at the end */
struct ti_temp_sensor sensors[];
int ti_bandgap_read_thot(struct ti_bandgap *bgp, int id, int *thot);
int ti_bandgap_write_thot(struct ti_bandgap *bgp, int id, int val);
int ti_bandgap_read_tcold(struct ti_bandgap *bgp, int id, int *tcold);
int ti_bandgap_write_tcold(struct ti_bandgap *bgp, int id, int val);
int ti_bandgap_read_update_interval(struct ti_bandgap *bgp, int id,
int *interval);
int ti_bandgap_write_update_interval(struct ti_bandgap *bgp, int id,
u32 interval);
int ti_bandgap_read_temperature(struct ti_bandgap *bgp, int id,
int *temperature);
int ti_bandgap_set_sensor_data(struct ti_bandgap *bgp, int id, void *data);
void *ti_bandgap_get_sensor_data(struct ti_bandgap *bgp, int id);
int ti_bandgap_get_trend(struct ti_bandgap *bgp, int id, int *trend);
extern const struct ti_bandgap_data omap34xx_data;
extern const struct ti_bandgap_data omap36xx_data;
#define omap34xx_data NULL
#define omap36xx_data NULL
extern const struct ti_bandgap_data omap4430_data;
extern const struct ti_bandgap_data omap4460_data;
extern const struct ti_bandgap_data omap4470_data;
#define omap4430_data NULL
#define omap4460_data NULL
#define omap4470_data NULL
extern const struct ti_bandgap_data omap5430_data;
#define omap5430_data NULL
extern const struct ti_bandgap_data dra752_data;
#define dra752_data NULL