--- /dev/null
+/*
+ * 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>");
git.samba.org / sfrench / cifs-2.6.git / commitdiff