/* * 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 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * 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. * */ #include #include #include #include #include #include #include #include #include /* 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 /* 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; }; struct rcar_gen3_thermal_priv { struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM]; unsigned int num_tscs; }; struct rcar_gen3_thermal_data { 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 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 96 #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]) * 137) / (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 struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = { .get_temp = rcar_gen3_thermal_get_temp, }; static void r8a7795_thermal_init(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_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 r8a7796_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); 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 rcar_gen3_thermal_data r8a7795_data = { .thermal_init = r8a7795_thermal_init, }; static const struct rcar_gen3_thermal_data r8a7796_data = { .thermal_init = r8a7796_thermal_init, }; static const struct of_device_id rcar_gen3_thermal_dt_ids[] = { { .compatible = "renesas,r8a7795-thermal", .data = &r8a7795_data}, { .compatible = "renesas,r8a7796-thermal", .data = &r8a7796_data}, {}, }; MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids); static int rcar_gen3_thermal_remove(struct platform_device *pdev) { struct device *dev = &pdev->dev; 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, i; const struct rcar_gen3_thermal_data *match_data = of_device_get_match_data(dev); /* default values if FUSEs are missing */ /* TODO: Read values from hardware on supported platforms */ int ptat[3] = { 2351, 1509, 435 }; int thcode[TSC_MAX_NUM][3] = { { 3248, 2800, 2221 }, { 3245, 2795, 2216 }, { 3250, 2805, 2237 }, }; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; platform_set_drvdata(pdev, priv); 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; match_data->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; } priv->num_tscs = i; if (!priv->num_tscs) { ret = -ENODEV; goto error_unregister; } return 0; error_unregister: rcar_gen3_thermal_remove(pdev); return ret; } static struct platform_driver rcar_gen3_thermal_driver = { .driver = { .name = "rcar_gen3_thermal", .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 ");