From 0c00477daee106502d89f9e724aee8bf405a81b8 Mon Sep 17 00:00:00 2001 From: Eduardo Valentin Date: Fri, 15 Mar 2013 08:59:52 -0400 Subject: [PATCH] staging: omap-thermal: update documentation of omap-bandgap.h This patch updates the existing data structures for omap bandgap, inside omap-bandgap.h. TODO: remove unused fields. Signed-off-by: Eduardo Valentin Signed-off-by: Greg Kroah-Hartman --- drivers/staging/omap-thermal/omap-bandgap.h | 230 ++++++++++++++++---- 1 file changed, 189 insertions(+), 41 deletions(-) diff --git a/drivers/staging/omap-thermal/omap-bandgap.h b/drivers/staging/omap-thermal/omap-bandgap.h index 7d5ac3fa91c5..28d9104369cc 100644 --- a/drivers/staging/omap-thermal/omap-bandgap.h +++ b/drivers/staging/omap-thermal/omap-bandgap.h @@ -28,24 +28,101 @@ #include /** - * 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; @@ -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; @@ -93,23 +187,27 @@ 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; @@ -117,7 +215,7 @@ struct omap_bandgap { 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; @@ -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; @@ -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; @@ -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) @@ -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; -- 2.30.2