diff options
Diffstat (limited to 'drivers/thermal/qcom/tsens-common.c')
| -rw-r--r-- | drivers/thermal/qcom/tsens-common.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c new file mode 100644 index 000000000000..b1449ad67fc0 --- /dev/null +++ b/drivers/thermal/qcom/tsens-common.c @@ -0,0 +1,141 @@ +/* + * Copyright (c) 2015, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * 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/err.h> +#include <linux/io.h> +#include <linux/nvmem-consumer.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include "tsens.h" + +#define S0_ST_ADDR 0x1030 +#define SN_ADDR_OFFSET 0x4 +#define SN_ST_TEMP_MASK 0x3ff +#define CAL_DEGC_PT1 30 +#define CAL_DEGC_PT2 120 +#define SLOPE_FACTOR 1000 +#define SLOPE_DEFAULT 3200 + +char *qfprom_read(struct device *dev, const char *cname) +{ + struct nvmem_cell *cell; + ssize_t data; + char *ret; + + cell = nvmem_cell_get(dev, cname); + if (IS_ERR(cell)) + return ERR_CAST(cell); + + ret = nvmem_cell_read(cell, &data); + nvmem_cell_put(cell); + + return ret; +} + +/* + * Use this function on devices where slope and offset calculations + * depend on calibration data read from qfprom. On others the slope + * and offset values are derived from tz->tzp->slope and tz->tzp->offset + * resp. + */ +void compute_intercept_slope(struct tsens_device *tmdev, u32 *p1, + u32 *p2, u32 mode) +{ + int i; + int num, den; + + for (i = 0; i < tmdev->num_sensors; i++) { + dev_dbg(tmdev->dev, + "sensor%d - data_point1:%#x data_point2:%#x\n", + i, p1[i], p2[i]); + + tmdev->sensor[i].slope = SLOPE_DEFAULT; + if (mode == TWO_PT_CALIB) { + /* + * slope (m) = adc_code2 - adc_code1 (y2 - y1)/ + * temp_120_degc - temp_30_degc (x2 - x1) + */ + num = p2[i] - p1[i]; + num *= SLOPE_FACTOR; + den = CAL_DEGC_PT2 - CAL_DEGC_PT1; + tmdev->sensor[i].slope = num / den; + } + + tmdev->sensor[i].offset = (p1[i] * SLOPE_FACTOR) - + (CAL_DEGC_PT1 * + tmdev->sensor[i].slope); + dev_dbg(tmdev->dev, "offset:%d\n", tmdev->sensor[i].offset); + } +} + +static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s) +{ + int degc, num, den; + + num = (adc_code * SLOPE_FACTOR) - s->offset; + den = s->slope; + + if (num > 0) + degc = num + (den / 2); + else if (num < 0) + degc = num - (den / 2); + else + degc = num; + + degc /= den; + + return degc; +} + +int get_temp_common(struct tsens_device *tmdev, int id, int *temp) +{ + struct tsens_sensor *s = &tmdev->sensor[id]; + u32 code; + unsigned int sensor_addr; + int last_temp = 0, ret; + + sensor_addr = S0_ST_ADDR + s->hw_id * SN_ADDR_OFFSET; + ret = regmap_read(tmdev->map, sensor_addr, &code); + if (ret) + return ret; + last_temp = code & SN_ST_TEMP_MASK; + + *temp = code_to_degc(last_temp, s) * 1000; + + return 0; +} + +static const struct regmap_config tsens_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, +}; + +int __init init_common(struct tsens_device *tmdev) +{ + void __iomem *base; + + base = of_iomap(tmdev->dev->of_node, 0); + if (!base) + return -EINVAL; + + tmdev->map = devm_regmap_init_mmio(tmdev->dev, base, &tsens_config); + if (IS_ERR(tmdev->map)) { + iounmap(base); + return PTR_ERR(tmdev->map); + } + + return 0; +} |