diff options
Diffstat (limited to 'drivers/thermal/broadcom/brcmstb_thermal.c')
| -rw-r--r-- | drivers/thermal/broadcom/brcmstb_thermal.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/thermal/broadcom/brcmstb_thermal.c b/drivers/thermal/broadcom/brcmstb_thermal.c new file mode 100644 index 000000000..8d16a41ea --- /dev/null +++ b/drivers/thermal/broadcom/brcmstb_thermal.c @@ -0,0 +1,374 @@ +/* + * Broadcom STB AVS TMON thermal sensor driver + * + * Copyright (c) 2015-2017 Broadcom + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#define DRV_NAME "brcmstb_thermal" + +#define pr_fmt(fmt) DRV_NAME ": " fmt + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/irqreturn.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of_device.h> +#include <linux/thermal.h> + +#define AVS_TMON_STATUS 0x00 + #define AVS_TMON_STATUS_valid_msk BIT(11) + #define AVS_TMON_STATUS_data_msk GENMASK(10, 1) + #define AVS_TMON_STATUS_data_shift 1 + +#define AVS_TMON_EN_OVERTEMP_RESET 0x04 + #define AVS_TMON_EN_OVERTEMP_RESET_msk BIT(0) + +#define AVS_TMON_RESET_THRESH 0x08 + #define AVS_TMON_RESET_THRESH_msk GENMASK(10, 1) + #define AVS_TMON_RESET_THRESH_shift 1 + +#define AVS_TMON_INT_IDLE_TIME 0x10 + +#define AVS_TMON_EN_TEMP_INT_SRCS 0x14 + #define AVS_TMON_EN_TEMP_INT_SRCS_high BIT(1) + #define AVS_TMON_EN_TEMP_INT_SRCS_low BIT(0) + +#define AVS_TMON_INT_THRESH 0x18 + #define AVS_TMON_INT_THRESH_high_msk GENMASK(26, 17) + #define AVS_TMON_INT_THRESH_high_shift 17 + #define AVS_TMON_INT_THRESH_low_msk GENMASK(10, 1) + #define AVS_TMON_INT_THRESH_low_shift 1 + +#define AVS_TMON_TEMP_INT_CODE 0x1c +#define AVS_TMON_TP_TEST_ENABLE 0x20 + +/* Default coefficients */ +#define AVS_TMON_TEMP_SLOPE 487 +#define AVS_TMON_TEMP_OFFSET 410040 + +/* HW related temperature constants */ +#define AVS_TMON_TEMP_MAX 0x3ff +#define AVS_TMON_TEMP_MIN -88161 +#define AVS_TMON_TEMP_MASK AVS_TMON_TEMP_MAX + +enum avs_tmon_trip_type { + TMON_TRIP_TYPE_LOW = 0, + TMON_TRIP_TYPE_HIGH, + TMON_TRIP_TYPE_RESET, + TMON_TRIP_TYPE_MAX, +}; + +struct avs_tmon_trip { + /* HW bit to enable the trip */ + u32 enable_offs; + u32 enable_mask; + + /* HW field to read the trip temperature */ + u32 reg_offs; + u32 reg_msk; + int reg_shift; +}; + +static struct avs_tmon_trip avs_tmon_trips[] = { + /* Trips when temperature is below threshold */ + [TMON_TRIP_TYPE_LOW] = { + .enable_offs = AVS_TMON_EN_TEMP_INT_SRCS, + .enable_mask = AVS_TMON_EN_TEMP_INT_SRCS_low, + .reg_offs = AVS_TMON_INT_THRESH, + .reg_msk = AVS_TMON_INT_THRESH_low_msk, + .reg_shift = AVS_TMON_INT_THRESH_low_shift, + }, + /* Trips when temperature is above threshold */ + [TMON_TRIP_TYPE_HIGH] = { + .enable_offs = AVS_TMON_EN_TEMP_INT_SRCS, + .enable_mask = AVS_TMON_EN_TEMP_INT_SRCS_high, + .reg_offs = AVS_TMON_INT_THRESH, + .reg_msk = AVS_TMON_INT_THRESH_high_msk, + .reg_shift = AVS_TMON_INT_THRESH_high_shift, + }, + /* Automatically resets chip when above threshold */ + [TMON_TRIP_TYPE_RESET] = { + .enable_offs = AVS_TMON_EN_OVERTEMP_RESET, + .enable_mask = AVS_TMON_EN_OVERTEMP_RESET_msk, + .reg_offs = AVS_TMON_RESET_THRESH, + .reg_msk = AVS_TMON_RESET_THRESH_msk, + .reg_shift = AVS_TMON_RESET_THRESH_shift, + }, +}; + +struct brcmstb_thermal_priv { + void __iomem *tmon_base; + struct device *dev; + struct thermal_zone_device *thermal; +}; + +/* Convert a HW code to a temperature reading (millidegree celsius) */ +static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz, + u32 code) +{ + return (AVS_TMON_TEMP_OFFSET - + (int)((code & AVS_TMON_TEMP_MAX) * AVS_TMON_TEMP_SLOPE)); +} + +/* + * Convert a temperature value (millidegree celsius) to a HW code + * + * @temp: temperature to convert + * @low: if true, round toward the low side + */ +static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz, + int temp, bool low) +{ + if (temp < AVS_TMON_TEMP_MIN) + return AVS_TMON_TEMP_MAX; /* Maximum code value */ + + if (temp >= AVS_TMON_TEMP_OFFSET) + return 0; /* Minimum code value */ + + if (low) + return (u32)(DIV_ROUND_UP(AVS_TMON_TEMP_OFFSET - temp, + AVS_TMON_TEMP_SLOPE)); + else + return (u32)((AVS_TMON_TEMP_OFFSET - temp) / + AVS_TMON_TEMP_SLOPE); +} + +static int brcmstb_get_temp(void *data, int *temp) +{ + struct brcmstb_thermal_priv *priv = data; + u32 val; + long t; + + val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS); + + if (!(val & AVS_TMON_STATUS_valid_msk)) { + dev_err(priv->dev, "reading not valid\n"); + return -EIO; + } + + val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift; + + t = avs_tmon_code_to_temp(priv->thermal, val); + if (t < 0) + *temp = 0; + else + *temp = t; + + return 0; +} + +static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv, + enum avs_tmon_trip_type type, int en) +{ + struct avs_tmon_trip *trip = &avs_tmon_trips[type]; + u32 val = __raw_readl(priv->tmon_base + trip->enable_offs); + + dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type); + + if (en) + val |= trip->enable_mask; + else + val &= ~trip->enable_mask; + + __raw_writel(val, priv->tmon_base + trip->enable_offs); +} + +static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv, + enum avs_tmon_trip_type type) +{ + struct avs_tmon_trip *trip = &avs_tmon_trips[type]; + u32 val = __raw_readl(priv->tmon_base + trip->reg_offs); + + val &= trip->reg_msk; + val >>= trip->reg_shift; + + return avs_tmon_code_to_temp(priv->thermal, val); +} + +static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv, + enum avs_tmon_trip_type type, + int temp) +{ + struct avs_tmon_trip *trip = &avs_tmon_trips[type]; + u32 val, orig; + + dev_dbg(priv->dev, "set temp %d to %d\n", type, temp); + + /* round toward low temp for the low interrupt */ + val = avs_tmon_temp_to_code(priv->thermal, temp, + type == TMON_TRIP_TYPE_LOW); + + val <<= trip->reg_shift; + val &= trip->reg_msk; + + orig = __raw_readl(priv->tmon_base + trip->reg_offs); + orig &= ~trip->reg_msk; + orig |= val; + __raw_writel(orig, priv->tmon_base + trip->reg_offs); +} + +static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv) +{ + u32 val; + + val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE); + return avs_tmon_code_to_temp(priv->thermal, val); +} + +static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data) +{ + struct brcmstb_thermal_priv *priv = data; + int low, high, intr; + + low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW); + high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH); + intr = avs_tmon_get_intr_temp(priv); + + dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n", + low, intr, high); + + /* Disable high-temp until next threshold shift */ + if (intr >= high) + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0); + /* Disable low-temp until next threshold shift */ + if (intr <= low) + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0); + + /* + * Notify using the interrupt temperature, in case the temperature + * changes before it can next be read out + */ + thermal_zone_device_update(priv->thermal, intr); + + return IRQ_HANDLED; +} + +static int brcmstb_set_trips(void *data, int low, int high) +{ + struct brcmstb_thermal_priv *priv = data; + + dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high); + + /* + * Disable low-temp if "low" is too small. As per thermal framework + * API, we use -INT_MAX rather than INT_MIN. + */ + if (low <= -INT_MAX) { + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0); + } else { + avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low); + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1); + } + + /* Disable high-temp if "high" is too big. */ + if (high == INT_MAX) { + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0); + } else { + avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high); + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1); + } + + return 0; +} + +static struct thermal_zone_of_device_ops of_ops = { + .get_temp = brcmstb_get_temp, + .set_trips = brcmstb_set_trips, +}; + +static const struct of_device_id brcmstb_thermal_id_table[] = { + { .compatible = "brcm,avs-tmon" }, + {}, +}; +MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table); + +static int brcmstb_thermal_probe(struct platform_device *pdev) +{ + struct thermal_zone_device *thermal; + struct brcmstb_thermal_priv *priv; + struct resource *res; + int irq, ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->tmon_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(priv->tmon_base)) + return PTR_ERR(priv->tmon_base); + + priv->dev = &pdev->dev; + platform_set_drvdata(pdev, priv); + + thermal = thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &of_ops); + if (IS_ERR(thermal)) { + ret = PTR_ERR(thermal); + dev_err(&pdev->dev, "could not register sensor: %d\n", ret); + return ret; + } + + priv->thermal = thermal; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "could not get IRQ\n"); + ret = irq; + goto err; + } + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, + brcmstb_tmon_irq_thread, IRQF_ONESHOT, + DRV_NAME, priv); + if (ret < 0) { + dev_err(&pdev->dev, "could not request IRQ: %d\n", ret); + goto err; + } + + dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n"); + + return 0; + +err: + thermal_zone_of_sensor_unregister(&pdev->dev, thermal); + return ret; +} + +static int brcmstb_thermal_exit(struct platform_device *pdev) +{ + struct brcmstb_thermal_priv *priv = platform_get_drvdata(pdev); + struct thermal_zone_device *thermal = priv->thermal; + + if (thermal) + thermal_zone_of_sensor_unregister(&pdev->dev, priv->thermal); + + return 0; +} + +static struct platform_driver brcmstb_thermal_driver = { + .probe = brcmstb_thermal_probe, + .remove = brcmstb_thermal_exit, + .driver = { + .name = DRV_NAME, + .of_match_table = brcmstb_thermal_id_table, + }, +}; +module_platform_driver(brcmstb_thermal_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Brian Norris"); +MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver"); |