diff options
| -rw-r--r-- | drivers/thermal/armada_thermal.c | 270 |
1 files changed, 269 insertions, 1 deletions
diff --git a/drivers/thermal/armada_thermal.c b/drivers/thermal/armada_thermal.c index 4b36a3022849..df3054b0ae6b 100644 --- a/drivers/thermal/armada_thermal.c +++ b/drivers/thermal/armada_thermal.c @@ -26,6 +26,11 @@ #include <linux/iopoll.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> +#include <linux/interrupt.h> + +#include "thermal_core.h" + +#define TO_MCELSIUS(c) ((c) * 1000) /* Thermal Manager Control and Status Register */ #define PMU_TDC0_SW_RST_MASK (0x1 << 1) @@ -61,9 +66,13 @@ #define CONTROL1_TSEN_AVG_MASK 0x7 #define CONTROL1_EXT_TSEN_SW_RESET BIT(7) #define CONTROL1_EXT_TSEN_HW_RESETn BIT(8) +#define CONTROL1_TSEN_INT_EN BIT(25) +#define CONTROL1_TSEN_SELECT_OFF 21 +#define CONTROL1_TSEN_SELECT_MASK 0x3 #define STATUS_POLL_PERIOD_US 1000 #define STATUS_POLL_TIMEOUT_US 100000 +#define OVERHEAT_INT_POLL_DELAY_MS 1000 struct armada_thermal_data; @@ -75,7 +84,11 @@ struct armada_thermal_priv { /* serialize temperature reads/updates */ struct mutex update_lock; struct armada_thermal_data *data; + struct thermal_zone_device *overheat_sensor; + int interrupt_source; int current_channel; + long current_threshold; + long current_hysteresis; }; struct armada_thermal_data { @@ -93,12 +106,20 @@ struct armada_thermal_data { /* Register shift and mask to access the sensor temperature */ unsigned int temp_shift; unsigned int temp_mask; + unsigned int thresh_shift; + unsigned int hyst_shift; + unsigned int hyst_mask; u32 is_valid_bit; /* Syscon access */ unsigned int syscon_control0_off; unsigned int syscon_control1_off; unsigned int syscon_status_off; + unsigned int dfx_irq_cause_off; + unsigned int dfx_irq_mask_off; + unsigned int dfx_overheat_irq; + unsigned int dfx_server_irq_mask_off; + unsigned int dfx_server_irq_en; /* One sensor is in the thermal IC, the others are in the CPUs if any */ unsigned int cpu_nr; @@ -272,6 +293,41 @@ static bool armada_is_valid(struct armada_thermal_priv *priv) return reg & priv->data->is_valid_bit; } +static void armada_enable_overheat_interrupt(struct armada_thermal_priv *priv) +{ + struct armada_thermal_data *data = priv->data; + u32 reg; + + /* Clear DFX temperature IRQ cause */ + regmap_read(priv->syscon, data->dfx_irq_cause_off, ®); + + /* Enable DFX Temperature IRQ */ + regmap_read(priv->syscon, data->dfx_irq_mask_off, ®); + reg |= data->dfx_overheat_irq; + regmap_write(priv->syscon, data->dfx_irq_mask_off, reg); + + /* Enable DFX server IRQ */ + regmap_read(priv->syscon, data->dfx_server_irq_mask_off, ®); + reg |= data->dfx_server_irq_en; + regmap_write(priv->syscon, data->dfx_server_irq_mask_off, reg); + + /* Enable overheat interrupt */ + regmap_read(priv->syscon, data->syscon_control1_off, ®); + reg |= CONTROL1_TSEN_INT_EN; + regmap_write(priv->syscon, data->syscon_control1_off, reg); +} + +static void __maybe_unused +armada_disable_overheat_interrupt(struct armada_thermal_priv *priv) +{ + struct armada_thermal_data *data = priv->data; + u32 reg; + + regmap_read(priv->syscon, data->syscon_control1_off, ®); + reg &= ~CONTROL1_TSEN_INT_EN; + regmap_write(priv->syscon, data->syscon_control1_off, reg); +} + /* There is currently no board with more than one sensor per channel */ static int armada_select_channel(struct armada_thermal_priv *priv, int channel) { @@ -388,6 +444,14 @@ static int armada_get_temp(void *_sensor, int *temp) /* Do the actual reading */ ret = armada_read_sensor(priv, temp); + if (ret) + goto unlock_mutex; + + /* + * Select back the interrupt source channel from which a potential + * critical trip point has been set. + */ + ret = armada_select_channel(priv, priv->interrupt_source); unlock_mutex: mutex_unlock(&priv->update_lock); @@ -399,6 +463,123 @@ static struct thermal_zone_of_device_ops of_ops = { .get_temp = armada_get_temp, }; +static unsigned int armada_mc_to_reg_temp(struct armada_thermal_data *data, + unsigned int temp_mc) +{ + s64 b = data->coef_b; + s64 m = data->coef_m; + s64 div = data->coef_div; + unsigned int sample; + + if (data->inverted) + sample = div_s64(((temp_mc * div) + b), m); + else + sample = div_s64((b - (temp_mc * div)), m); + + return sample & data->temp_mask; +} + +/* + * The documentation states: + * high/low watermark = threshold +/- 0.4761 * 2^(hysteresis + 2) + * which is the mathematical derivation for: + * 0x0 <=> 1.9°C, 0x1 <=> 3.8°C, 0x2 <=> 7.6°C, 0x3 <=> 15.2°C + */ +static unsigned int hyst_levels_mc[] = {1900, 3800, 7600, 15200}; + +static unsigned int armada_mc_to_reg_hyst(struct armada_thermal_data *data, + unsigned int hyst_mc) +{ + int i; + + /* + * We will always take the smallest possible hysteresis to avoid risking + * the hardware integrity by enlarging the threshold by +8°C in the + * worst case. + */ + for (i = ARRAY_SIZE(hyst_levels_mc) - 1; i > 0; i--) + if (hyst_mc >= hyst_levels_mc[i]) + break; + + return i & data->hyst_mask; +} + +static void armada_set_overheat_thresholds(struct armada_thermal_priv *priv, + int thresh_mc, int hyst_mc) +{ + struct armada_thermal_data *data = priv->data; + unsigned int threshold = armada_mc_to_reg_temp(data, thresh_mc); + unsigned int hysteresis = armada_mc_to_reg_hyst(data, hyst_mc); + u32 ctrl1; + + regmap_read(priv->syscon, data->syscon_control1_off, &ctrl1); + + /* Set Threshold */ + if (thresh_mc >= 0) { + ctrl1 &= ~(data->temp_mask << data->thresh_shift); + ctrl1 |= threshold << data->thresh_shift; + priv->current_threshold = thresh_mc; + } + + /* Set Hysteresis */ + if (hyst_mc >= 0) { + ctrl1 &= ~(data->hyst_mask << data->hyst_shift); + ctrl1 |= hysteresis << data->hyst_shift; + priv->current_hysteresis = hyst_mc; + } + + regmap_write(priv->syscon, data->syscon_control1_off, ctrl1); +} + +static irqreturn_t armada_overheat_isr(int irq, void *blob) +{ + /* + * Disable the IRQ and continue in thread context (thermal core + * notification and temperature monitoring). + */ + disable_irq_nosync(irq); + + return IRQ_WAKE_THREAD; +} + +static irqreturn_t armada_overheat_isr_thread(int irq, void *blob) +{ + struct armada_thermal_priv *priv = blob; + int low_threshold = priv->current_threshold - priv->current_hysteresis; + int temperature; + u32 dummy; + int ret; + + /* Notify the core in thread context */ + thermal_zone_device_update(priv->overheat_sensor, + THERMAL_EVENT_UNSPECIFIED); + + /* + * The overheat interrupt must be cleared by reading the DFX interrupt + * cause _after_ the temperature has fallen down to the low threshold. + * Otherwise future interrupts might not be served. + */ + do { + msleep(OVERHEAT_INT_POLL_DELAY_MS); + mutex_lock(&priv->update_lock); + ret = armada_read_sensor(priv, &temperature); + mutex_unlock(&priv->update_lock); + if (ret) + goto enable_irq; + } while (temperature >= low_threshold); + + regmap_read(priv->syscon, priv->data->dfx_irq_cause_off, &dummy); + + /* Notify the thermal core that the temperature is acceptable again */ + thermal_zone_device_update(priv->overheat_sensor, + THERMAL_EVENT_UNSPECIFIED); + +enable_irq: + enable_irq(irq); + + return IRQ_HANDLED; +} + static const struct armada_thermal_data armadaxp_data = { .init = armadaxp_init, .temp_shift = 10, @@ -454,6 +635,9 @@ static const struct armada_thermal_data armada_ap806_data = { .is_valid_bit = BIT(16), .temp_shift = 0, .temp_mask = 0x3ff, + .thresh_shift = 3, + .hyst_shift = 19, + .hyst_mask = 0x3, .coef_b = -150000LL, .coef_m = 423ULL, .coef_div = 1, @@ -462,6 +646,11 @@ static const struct armada_thermal_data armada_ap806_data = { .syscon_control0_off = 0x84, .syscon_control1_off = 0x88, .syscon_status_off = 0x8C, + .dfx_irq_cause_off = 0x108, + .dfx_irq_mask_off = 0x10C, + .dfx_overheat_irq = BIT(22), + .dfx_server_irq_mask_off = 0x104, + .dfx_server_irq_en = BIT(1), .cpu_nr = 4, }; @@ -470,6 +659,9 @@ static const struct armada_thermal_data armada_cp110_data = { .is_valid_bit = BIT(10), .temp_shift = 0, .temp_mask = 0x3ff, + .thresh_shift = 16, + .hyst_shift = 26, + .hyst_mask = 0x3, .coef_b = 1172499100ULL, .coef_m = 2000096ULL, .coef_div = 4201, @@ -477,6 +669,11 @@ static const struct armada_thermal_data armada_cp110_data = { .syscon_control0_off = 0x70, .syscon_control1_off = 0x74, .syscon_status_off = 0x78, + .dfx_irq_cause_off = 0x108, + .dfx_irq_mask_off = 0x10C, + .dfx_overheat_irq = BIT(20), + .dfx_server_irq_mask_off = 0x104, + .dfx_server_irq_en = BIT(1), }; static const struct of_device_id armada_thermal_id_table[] = { @@ -586,6 +783,48 @@ static void armada_set_sane_name(struct platform_device *pdev, } while (insane_char); } +/* + * The IP can manage to trigger interrupts on overheat situation from all the + * sensors. However, the interrupt source changes along with the last selected + * source (ie. the last read sensor), which is an inconsistent behavior. Avoid + * possible glitches by always selecting back only one channel (arbitrarily: the + * first in the DT which has a critical trip point). We also disable sensor + * switch during overheat situations. + */ +static int armada_configure_overheat_int(struct armada_thermal_priv *priv, + struct thermal_zone_device *tz, + int sensor_id) +{ + /* Retrieve the critical trip point to enable the overheat interrupt */ + const struct thermal_trip *trips = of_thermal_get_trip_points(tz); + int ret; + int i; + + if (!trips) + return -EINVAL; + + for (i = 0; i < of_thermal_get_ntrips(tz); i++) + if (trips[i].type == THERMAL_TRIP_CRITICAL) + break; + + if (i == of_thermal_get_ntrips(tz)) + return -EINVAL; + + ret = armada_select_channel(priv, sensor_id); + if (ret) + return ret; + + armada_set_overheat_thresholds(priv, + trips[i].temperature, + trips[i].hysteresis); + priv->overheat_sensor = tz; + priv->interrupt_source = sensor_id; + + armada_enable_overheat_interrupt(priv); + + return 0; +} + static int armada_thermal_probe(struct platform_device *pdev) { struct thermal_zone_device *tz; @@ -593,7 +832,7 @@ static int armada_thermal_probe(struct platform_device *pdev) struct armada_drvdata *drvdata; const struct of_device_id *match; struct armada_thermal_priv *priv; - int sensor_id; + int sensor_id, irq; int ret; match = of_match_device(armada_thermal_id_table, &pdev->dev); @@ -663,6 +902,23 @@ static int armada_thermal_probe(struct platform_device *pdev) drvdata->data.priv = priv; platform_set_drvdata(pdev, drvdata); + irq = platform_get_irq(pdev, 0); + if (irq == -EPROBE_DEFER) + return irq; + + /* The overheat interrupt feature is not mandatory */ + if (irq > 0) { + ret = devm_request_threaded_irq(&pdev->dev, irq, + armada_overheat_isr, + armada_overheat_isr_thread, + 0, NULL, priv); + if (ret) { + dev_err(&pdev->dev, "Cannot request threaded IRQ %d\n", + irq); + return ret; + } + } + /* * There is one channel for the IC and one per CPU (if any), each * channel has one sensor. @@ -686,8 +942,20 @@ static int armada_thermal_probe(struct platform_device *pdev) devm_kfree(&pdev->dev, sensor); continue; } + + /* + * The first channel that has a critical trip point registered + * in the DT will serve as interrupt source. Others possible + * critical trip points will simply be ignored by the driver. + */ + if (irq > 0 && !priv->overheat_sensor) + armada_configure_overheat_int(priv, tz, sensor->id); } + /* Just complain if no overheat interrupt was set up */ + if (!priv->overheat_sensor) + dev_warn(&pdev->dev, "Overheat interrupt not available\n"); + return 0; } |