Hi Rajendra, One comment below.
Rajendra Nayak <[email protected]> writes: > Add support to calibrate sensors on 8916 family and also add common > functions to read temperature from sensors (This can be reused on > other SoCs having similar TSENS device) > The calibration data is read from eeprom using the generic nvmem > framework apis. > > Based on the original code by Siddartha Mohanadoss and Stephen Boyd. > > Signed-off-by: Rajendra Nayak <[email protected]> > --- > drivers/thermal/qcom/Makefile | 2 +- > drivers/thermal/qcom/tsens-8916.c | 107 +++++++++++++++++++++++++++++ > drivers/thermal/qcom/tsens-common.c | 130 > ++++++++++++++++++++++++++++++++++++ > drivers/thermal/qcom/tsens.c | 1 + > drivers/thermal/qcom/tsens.h | 11 +++ > 5 files changed, 250 insertions(+), 1 deletion(-) > create mode 100644 drivers/thermal/qcom/tsens-8916.c > create mode 100644 drivers/thermal/qcom/tsens-common.c > [...] > diff --git a/drivers/thermal/qcom/tsens-common.c > b/drivers/thermal/qcom/tsens-common.c > new file mode 100644 > index 0000000..4acf52c > --- /dev/null > +++ b/drivers/thermal/qcom/tsens-common.c > @@ -0,0 +1,130 @@ > +/* > + * 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/platform_device.h> > +#include <linux/nvmem-consumer.h> > +#include <linux/err.h> > +#include <linux/io.h> > +#include <linux/of_address.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 > + > +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; > +} > + > +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]); > + > + 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; > +} The way this function is coded the temperature will only ever change by 1C (i.e., 1000mC). Is there a chance that you're losing precision in the code_to_degc conversion that could be preserved perhaps? This is useful in scenarios where you use the power allocator governor and the greater precision allows better power budget estimation. > + > +static const struct regmap_config tsens_config = { > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > +int init_common(struct tsens_device *tmdev) > +{ > + void __iomem *base; > + > + base = of_iomap(tmdev->dev->of_node, 0); > + if (IS_ERR(base)) > + return -EINVAL; > + > + tmdev->map = devm_regmap_init_mmio(tmdev->dev, base, &tsens_config); > + if (!tmdev->map) > + return -ENODEV; > + > + return 0; > +} [...] -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
