| /* |
| * 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 <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of_device.h> |
| #include <linux/platform_device.h> |
| #include <linux/pm_runtime.h> |
| #include <linux/thermal.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 |
| |
| /* 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 mutex lock; |
| }; |
| |
| struct rcar_gen3_thermal_priv { |
| struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM]; |
| }; |
| |
| 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 */ |
| mutex_lock(&tsc->lock); |
| |
| 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); |
| |
| mutex_unlock(&tsc->lock); |
| |
| /* 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); |
| } |
| |
| 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; |
| |
| tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL); |
| if (!tsc) { |
| ret = -ENOMEM; |
| goto error_unregister; |
| } |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, i); |
| if (!res) |
| break; |
| |
| tsc->base = devm_ioremap_resource(dev, res); |
| if (IS_ERR(tsc->base)) { |
| ret = PTR_ERR(tsc->base); |
| goto error_unregister; |
| } |
| |
| priv->tscs[i] = tsc; |
| mutex_init(&tsc->lock); |
| |
| 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; |
| } |
| |
| 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 <wsa+renesas@sang-engineering.com>"); |