diff options
Diffstat (limited to 'drivers/thermal/rcar_gen3_thermal.c')
| -rw-r--r-- | drivers/thermal/rcar_gen3_thermal.c | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c new file mode 100644 index 000000000..8f553453d --- /dev/null +++ b/drivers/thermal/rcar_gen3_thermal.c @@ -0,0 +1,469 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * R-Car Gen3 THS thermal sensor driver + * Based on rcar_thermal.c and work from Hien Dang and Khiem Nguyen. + * + * Copyright (C) 2016 Renesas Electronics Corporation. + * Copyright (C) 2016 Sang Engineering + */ +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/sys_soc.h> +#include <linux/thermal.h> + +#include "thermal_core.h" + +/* Register offsets */ +#define REG_GEN3_IRQSTR 0x04 +#define REG_GEN3_IRQMSK 0x08 +#define REG_GEN3_IRQCTL 0x0C +#define REG_GEN3_IRQEN 0x10 +#define REG_GEN3_IRQTEMP1 0x14 +#define REG_GEN3_IRQTEMP2 0x18 +#define REG_GEN3_IRQTEMP3 0x1C +#define REG_GEN3_CTSR 0x20 +#define REG_GEN3_THCTR 0x20 +#define REG_GEN3_TEMP 0x28 +#define REG_GEN3_THCODE1 0x50 +#define REG_GEN3_THCODE2 0x54 +#define REG_GEN3_THCODE3 0x58 + +/* IRQ{STR,MSK,EN} bits */ +#define IRQ_TEMP1 BIT(0) +#define IRQ_TEMP2 BIT(1) +#define IRQ_TEMP3 BIT(2) +#define IRQ_TEMPD1 BIT(3) +#define IRQ_TEMPD2 BIT(4) +#define IRQ_TEMPD3 BIT(5) + +/* CTSR bits */ +#define CTSR_PONM BIT(8) +#define CTSR_AOUT BIT(7) +#define CTSR_THBGR BIT(5) +#define CTSR_VMEN BIT(4) +#define CTSR_VMST BIT(1) +#define CTSR_THSST BIT(0) + +/* THCTR bits */ +#define THCTR_PONM BIT(6) +#define THCTR_THSST BIT(0) + +#define CTEMP_MASK 0xFFF + +#define MCELSIUS(temp) ((temp) * 1000) +#define GEN3_FUSE_MASK 0xFFF + +#define TSC_MAX_NUM 3 + +/* Structure for thermal temperature calculation */ +struct equation_coefs { + int a1; + int b1; + int a2; + int b2; +}; + +struct rcar_gen3_thermal_tsc { + void __iomem *base; + struct thermal_zone_device *zone; + struct equation_coefs coef; + int low; + int high; +}; + +struct rcar_gen3_thermal_priv { + struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM]; + unsigned int num_tscs; + void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc); +}; + +static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc, + u32 reg) +{ + return ioread32(tsc->base + reg); +} + +static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc, + u32 reg, u32 data) +{ + iowrite32(data, tsc->base + reg); +} + +/* + * Linear approximation for temperature + * + * [reg] = [temp] * a + b => [temp] = ([reg] - b) / a + * + * The constants a and b are calculated using two triplets of int values PTAT + * and THCODE. PTAT and THCODE can either be read from hardware or use hard + * coded values from driver. The formula to calculate a and b are taken from + * BSP and sparsely documented and understood. + * + * Examining the linear formula and the formula used to calculate constants a + * and b while knowing that the span for PTAT and THCODE values are between + * 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001. + * Integer also needs to be signed so that leaves 7 bits for binary + * fixed point scaling. + */ + +#define FIXPT_SHIFT 7 +#define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT) +#define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT) +#define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b)) +#define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT) + +#define RCAR3_THERMAL_GRAN 500 /* mili Celsius */ + +/* no idea where these constants come from */ +#define TJ_1 116 +#define TJ_3 -41 + +static void rcar_gen3_thermal_calc_coefs(struct equation_coefs *coef, + int *ptat, int *thcode) +{ + int tj_2; + + /* TODO: Find documentation and document constant calculation formula */ + + /* + * Division is not scaled in BSP and if scaled it might overflow + * the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled + */ + tj_2 = (FIXPT_INT((ptat[1] - ptat[2]) * 157) + / (ptat[0] - ptat[2])) - FIXPT_INT(41); + + coef->a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]), + tj_2 - FIXPT_INT(TJ_3)); + coef->b1 = FIXPT_INT(thcode[2]) - coef->a1 * TJ_3; + + coef->a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]), + tj_2 - FIXPT_INT(TJ_1)); + coef->b2 = FIXPT_INT(thcode[0]) - coef->a2 * TJ_1; +} + +static int rcar_gen3_thermal_round(int temp) +{ + int result, round_offs; + + round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 : + -RCAR3_THERMAL_GRAN / 2; + result = (temp + round_offs) / RCAR3_THERMAL_GRAN; + return result * RCAR3_THERMAL_GRAN; +} + +static int rcar_gen3_thermal_get_temp(void *devdata, int *temp) +{ + struct rcar_gen3_thermal_tsc *tsc = devdata; + int mcelsius, val1, val2; + u32 reg; + + /* Read register and convert to mili Celsius */ + reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK; + + val1 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1, tsc->coef.a1); + val2 = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2, tsc->coef.a2); + mcelsius = FIXPT_TO_MCELSIUS((val1 + val2) / 2); + + /* Make sure we are inside specifications */ + if ((mcelsius < MCELSIUS(-40)) || (mcelsius > MCELSIUS(125))) + return -EIO; + + /* Round value to device granularity setting */ + *temp = rcar_gen3_thermal_round(mcelsius); + + return 0; +} + +static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc, + int mcelsius) +{ + int celsius, val1, val2; + + celsius = DIV_ROUND_CLOSEST(mcelsius, 1000); + val1 = celsius * tsc->coef.a1 + tsc->coef.b1; + val2 = celsius * tsc->coef.a2 + tsc->coef.b2; + + return INT_FIXPT((val1 + val2) / 2); +} + +static int rcar_gen3_thermal_set_trips(void *devdata, int low, int high) +{ + struct rcar_gen3_thermal_tsc *tsc = devdata; + + low = clamp_val(low, -40000, 120000); + high = clamp_val(high, -40000, 120000); + + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1, + rcar_gen3_thermal_mcelsius_to_temp(tsc, low)); + + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2, + rcar_gen3_thermal_mcelsius_to_temp(tsc, high)); + + tsc->low = low; + tsc->high = high; + + return 0; +} + +static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = { + .get_temp = rcar_gen3_thermal_get_temp, + .set_trips = rcar_gen3_thermal_set_trips, +}; + +static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on) +{ + unsigned int i; + u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0; + + for (i = 0; i < priv->num_tscs; i++) + rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val); +} + +static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data) +{ + struct rcar_gen3_thermal_priv *priv = data; + u32 status; + int i; + + for (i = 0; i < priv->num_tscs; i++) { + status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR); + rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0); + if (status) + thermal_zone_device_update(priv->tscs[i]->zone, + THERMAL_EVENT_UNSPECIFIED); + } + + return IRQ_HANDLED; +} + +static const struct soc_device_attribute r8a7795es1[] = { + { .soc_id = "r8a7795", .revision = "ES1.*" }, + { /* sentinel */ } +}; + +static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc) +{ + rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_THBGR); + rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, 0x0); + + usleep_range(1000, 2000); + + rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM); + + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F); + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0); + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2); + + rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, + CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN); + + usleep_range(100, 200); + + rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, + CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN | + CTSR_VMST | CTSR_THSST); + + usleep_range(1000, 2000); +} + +static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc) +{ + u32 reg_val; + + reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR); + reg_val &= ~THCTR_PONM; + rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val); + + usleep_range(1000, 2000); + + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F); + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0); + rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2); + + reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR); + reg_val |= THCTR_THSST; + rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val); + + usleep_range(1000, 2000); +} + +static const struct of_device_id rcar_gen3_thermal_dt_ids[] = { + { .compatible = "renesas,r8a7795-thermal", }, + { .compatible = "renesas,r8a7796-thermal", }, + { .compatible = "renesas,r8a77965-thermal", }, + {}, +}; +MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids); + +static int rcar_gen3_thermal_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev); + + rcar_thermal_irq_set(priv, false); + + pm_runtime_put(dev); + pm_runtime_disable(dev); + + return 0; +} + +static int rcar_gen3_thermal_probe(struct platform_device *pdev) +{ + struct rcar_gen3_thermal_priv *priv; + struct device *dev = &pdev->dev; + struct resource *res; + struct thermal_zone_device *zone; + int ret, irq, i; + char *irqname; + + /* default values if FUSEs are missing */ + /* TODO: Read values from hardware on supported platforms */ + int ptat[3] = { 2631, 1509, 435 }; + int thcode[TSC_MAX_NUM][3] = { + { 3397, 2800, 2221 }, + { 3393, 2795, 2216 }, + { 3389, 2805, 2237 }, + }; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->thermal_init = rcar_gen3_thermal_init; + if (soc_device_match(r8a7795es1)) + priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1; + + platform_set_drvdata(pdev, priv); + + /* + * Request 2 (of the 3 possible) IRQs, the driver only needs to + * to trigger on the low and high trip points of the current + * temp window at this point. + */ + for (i = 0; i < 2; i++) { + irq = platform_get_irq(pdev, i); + if (irq < 0) + return irq; + + irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d", + dev_name(dev), i); + if (!irqname) + return -ENOMEM; + + ret = devm_request_threaded_irq(dev, irq, NULL, + rcar_gen3_thermal_irq, + IRQF_ONESHOT, irqname, priv); + if (ret) + return ret; + } + + pm_runtime_enable(dev); + pm_runtime_get_sync(dev); + + for (i = 0; i < TSC_MAX_NUM; i++) { + struct rcar_gen3_thermal_tsc *tsc; + + res = platform_get_resource(pdev, IORESOURCE_MEM, i); + if (!res) + break; + + tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL); + if (!tsc) { + ret = -ENOMEM; + goto error_unregister; + } + + tsc->base = devm_ioremap_resource(dev, res); + if (IS_ERR(tsc->base)) { + ret = PTR_ERR(tsc->base); + goto error_unregister; + } + + priv->tscs[i] = tsc; + + priv->thermal_init(tsc); + rcar_gen3_thermal_calc_coefs(&tsc->coef, ptat, thcode[i]); + + zone = devm_thermal_zone_of_sensor_register(dev, i, tsc, + &rcar_gen3_tz_of_ops); + if (IS_ERR(zone)) { + dev_err(dev, "Can't register thermal zone\n"); + ret = PTR_ERR(zone); + goto error_unregister; + } + tsc->zone = zone; + + ret = of_thermal_get_ntrips(tsc->zone); + if (ret < 0) + goto error_unregister; + + dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret); + } + + priv->num_tscs = i; + + if (!priv->num_tscs) { + ret = -ENODEV; + goto error_unregister; + } + + rcar_thermal_irq_set(priv, true); + + return 0; + +error_unregister: + rcar_gen3_thermal_remove(pdev); + + return ret; +} + +static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev) +{ + struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev); + + rcar_thermal_irq_set(priv, false); + + return 0; +} + +static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev) +{ + struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev); + unsigned int i; + + for (i = 0; i < priv->num_tscs; i++) { + struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i]; + + priv->thermal_init(tsc); + rcar_gen3_thermal_set_trips(tsc, tsc->low, tsc->high); + } + + rcar_thermal_irq_set(priv, true); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend, + rcar_gen3_thermal_resume); + +static struct platform_driver rcar_gen3_thermal_driver = { + .driver = { + .name = "rcar_gen3_thermal", + .pm = &rcar_gen3_thermal_pm_ops, + .of_match_table = rcar_gen3_thermal_dt_ids, + }, + .probe = rcar_gen3_thermal_probe, + .remove = rcar_gen3_thermal_remove, +}; +module_platform_driver(rcar_gen3_thermal_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver"); +MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>"); 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