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staging: omap-thermal: update documentation of omap-bandgap.h
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This patch updates the existing data structures for omap bandgap,
inside omap-bandgap.h.

TODO: remove unused fields.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Eduardo Valentin authored and Greg Kroah-Hartman committed Mar 15, 2013
1 parent 787f3c2 commit 0c00477
Showing 1 changed file with 189 additions and 41 deletions.
230 changes: 189 additions & 41 deletions drivers/staging/omap-thermal/omap-bandgap.h
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Original file line number Diff line number Diff line change
Expand Up @@ -28,24 +28,101 @@
#include <linux/err.h>

/**
* The register offsets and bit fields might change across
* OMAP versions hence populating them in this structure.
* DOC: bandgap driver data structure
* ==================================
* +---------------------+ +-----------------+
* | struct omap_bandgap |-->| struct device * |
* +----------+----------+ +-----------------+
* |
* |
* V
* +--------------------------+
* | struct omap_bandgap_data |
* +--------------------------+
* |
* |
* * (Array of)
* +------------+------------------------------------------------------+
* | +----------+--------------+ +-------------------------+ |
* | | struct omap_temp_sensor |-->| struct temp_sensor_data | |
* | +-------------------------+ +------------+------------+ |
* | | |
* | +--------------------------+ |
* | V V |
* | +----------+- --------------+ +----+-------------------------+ |
* | | struct temp_sensor_regval | | 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 omap_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_sidlemode_mask: mask to bandgap_mask_ctrl.mask_sidlemode
* @mask_freeze_mask: mask to bandgap_mask_ctrl.mask_free
* @mask_clear_mask: mask to bandgap_mask_ctrl.mask_clear
* @mask_clear_accum_mask: mask to bandgap_mask_ctrl.mask_clear_accum
* @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_efuse_mask: mask to tshut_threshold.tshut_efuse
* @tshut_efuse_shift: shift to tshut_threshold.tshut_efuse
* @tshut_hot_mask: mask to tshut_threhold.thot
* @tshut_cold_mask: mask to tshut_threhold.thot
* @bgap_status: BANDGAP_STATUS register offset
* @status_clean_stop_mask: mask to bandgap_status.clean_stop
* @status_bgap_alert_mask: mask to bandgap_status.bandgap_alert
* @status_hot_mask: mask to bandgap_status.hot
* @status_cold_mask: mask to bandgap_status.cold
* @bgap_cumul_dtemp: BANDGAP_CUMUL_DTEMP register offset
* @ctrl_dtemp_0: CTRL_DTEMP0 register offset
* @ctrl_dtemp_1: CTRL_DTEMP1 register offset
* @ctrl_dtemp_2: CTRL_DTEMP2 register offset
* @ctrl_dtemp_3: CTRL_DTEMP3 register offset
* @ctrl_dtemp_4: CTRL_DTEMP4 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_eocz_mask; /* not used: but needs revisit */
u32 bgap_dtemp_mask;

u32 bgap_mask_ctrl;
u32 mask_hot_mask;
u32 mask_cold_mask;
u32 mask_sidlemode_mask;
u32 mask_sidlemode_mask; /* not used: but may be needed for pm */
u32 mask_freeze_mask;
u32 mask_clear_mask;
u32 mask_clear_accum_mask;
u32 mask_clear_mask; /* not used: but needed for trending */
u32 mask_clear_accum_mask; /* not used: but needed for trending */

u32 bgap_mode_ctrl;
u32 mode_ctrl_mask;
Expand All @@ -58,28 +135,45 @@ struct temp_sensor_registers {
u32 threshold_tcold_mask;

u32 tshut_threshold;
u32 tshut_efuse_mask;
u32 tshut_efuse_shift;
u32 tshut_efuse_mask; /* not used */
u32 tshut_efuse_shift; /* not used */
u32 tshut_hot_mask;
u32 tshut_cold_mask;

u32 bgap_status;
u32 status_clean_stop_mask;
u32 status_bgap_alert_mask;
u32 status_clean_stop_mask; /* not used: but needed for trending */
u32 status_bgap_alert_mask; /* not used */
u32 status_hot_mask;
u32 status_cold_mask;

u32 bgap_cumul_dtemp;
u32 ctrl_dtemp_0;
u32 ctrl_dtemp_1;
u32 ctrl_dtemp_2;
u32 ctrl_dtemp_3;
u32 ctrl_dtemp_4;
u32 bgap_cumul_dtemp; /* not used: but needed for trending */
u32 ctrl_dtemp_0; /* not used: but needed for trending */
u32 ctrl_dtemp_1; /* not used: but needed for trending */
u32 ctrl_dtemp_2; /* not used: but needed for trending */
u32 ctrl_dtemp_3; /* not used: but needed for trending */
u32 ctrl_dtemp_4; /* not used: but needed for trending */
u32 bgap_efuse;
};

/**
* The thresholds and limits for temperature sensors.
* 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
* @max_temp: sensor maximum temperature
* @min_temp: sensor minimum temperature
* @hyst_val: temperature hysteresis considered while converting ADC values
* @adc_start_val: ADC conversion table starting value
* @adc_end_val: ADC conversion table ending value
* @update_int1: update interval
* @update_int2: update interval
*
* 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;
Expand All @@ -93,31 +187,35 @@ struct temp_sensor_data {
int hyst_val;
u32 adc_start_val;
u32 adc_end_val;
u32 update_int1;
u32 update_int2;
u32 update_int1; /* not used */
u32 update_int2; /* not used */
};

struct omap_bandgap_data;

/**
* struct omap_bandgap - bandgap device structure
* @dev: device pointer
* @conf: platform data with sensor data
* @dev: struct device pointer
* @base: io memory base address
* @conf: struct with bandgap configuration set (# sensors, conv_table, etc)
* @fclock: pointer to functional clock of temperature sensor
* @div_clk: pointer to parent clock of temperature sensor fclk
* @conv_table: Pointer to adc to temperature conversion table
* @bg_mutex: Mutex for sysfs, irq and PM
* @irq: MPU Irq number for thermal alert
* @div_clk: pointer to divider clock of temperature sensor fclk
* @bg_mutex: mutex for omap_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 omap_bandgap {
struct device *dev;
void __iomem *base;
struct omap_bandgap_data *conf;
struct clk *fclock;
struct clk *div_clk;
struct mutex bg_mutex; /* Mutex for irq and PM */
struct mutex bg_mutex; /* shields this struct */
int irq;
int tshut_gpio;
u32 clk_rate;
Expand All @@ -130,6 +228,9 @@ struct omap_bandgap {
* @bg_counter: bandgap counter value
* @bg_threshold: bandgap threshold register value
* @tshut_threshold: bandgap tshut register value
*
* 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;
Expand All @@ -140,21 +241,26 @@ struct temp_sensor_regval {
};

/**
* struct omap_temp_sensor - bandgap temperature sensor platform data
* struct omap_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
* @regval: temperature sensor register values
* @domain: the name of the domain where the sensor is located
* @cooling_data: description on how the zone should be cooled off.
* @slope: sensor gradient slope info for hotspot extrapolation
* @const: sensor gradient const info for hotspot extrapolation
* @slope_pcb: sensor gradient slope info for hotspot extrapolation
* @slope: sensor gradient slope info for hotspot extrapolation equation
* @const: sensor gradient const info for hotspot extrapolation equation
* @slope_pcb: sensor gradient slope info for hotspot extrapolation equation
* with no external influence
* @const_pcb: sensor gradient const info for hotspot extrapolation
* @constant_pcb: sensor gradient const info for hotspot extrapolation equation
* with no external influence
* @data: private data
* @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 omap_temp_sensor {
struct temp_sensor_data *ts_data;
Expand All @@ -172,16 +278,38 @@ struct omap_temp_sensor {
};

/**
* struct omap_bandgap_data - bandgap platform data structure
* @features: a bitwise flag set to describe the device features
* @conv_table: Pointer to adc to temperature conversion table
* @fclock_name: clock name of the functional clock
* @div_ck_nme: clock name of the clock divisor
* @sensor_count: count of temperature sensor device in scm
* @sensors: array of sensors present in this bandgap instance
* @expose_sensor: callback to export sensor to thermal API
* DOC: omap bandgap feature types
*
* OMAP_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).
*
* OMAP_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.
*
* OMAP_BANDGAP_FEATURE_TALERT - used when the bandgap device instance outputs
* a signal representing violation of programmable alert thresholds.
*
* OMAP_BANDGAP_FEATURE_MODE_CONFIG - used when it is possible to choose which
* mode, continuous or one shot, the bandgap device instance will operate.
*
* OMAP_BANDGAP_FEATURE_COUNTER - used when the bandgap device instance allows
* programming the update interval of its internal state machine.
*
* OMAP_BANDGAP_FEATURE_POWER_SWITCH - used when the bandgap device allows
* itself to be switched on/off.
*
* OMAP_BANDGAP_FEATURE_CLK_CTRL - used when the clocks feeding the bandgap
* device are gateable or not.
*
* OMAP_BANDGAP_FEATURE_FREEZE_BIT - used when the bandgap device features
* a history buffer that its update can be freezed/unfreezed.
*
* OMAP_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.
*/
struct omap_bandgap_data {
#define OMAP_BANDGAP_FEATURE_TSHUT BIT(0)
#define OMAP_BANDGAP_FEATURE_TSHUT_CONFIG BIT(1)
#define OMAP_BANDGAP_FEATURE_TALERT BIT(2)
Expand All @@ -192,6 +320,26 @@ struct omap_bandgap_data {
#define OMAP_BANDGAP_FEATURE_FREEZE_BIT BIT(7)
#define OMAP_BANDGAP_HAS(b, f) \
((b)->conf->features & OMAP_BANDGAP_FEATURE_ ## f)

/**
* struct omap_bandgap_data - omap bandgap data configuration structure
* @features: a bitwise flag set to describe the device features
* @conv_table: Pointer to ADC to temperature conversion table
* @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 omap_bandgap_data {
unsigned int features;
const int *conv_table;
char *fclock_name;
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