Subject: [PATCH v4 2/8] thermal: qcom: tsens-8916: Add support for 8916 family of SoCs

From: [email-masked] (Eduardo Valentin)
Date: Mon, 2 Nov 2015 12:42:40 -0800

On Fri, Oct 09, 2015 at 03:11:04PM +0530, Rajendra Nayak wrote:
> 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-masked]>
> ---
>  drivers/thermal/qcom/Makefile       |   2 +-
>  drivers/thermal/qcom/tsens-8916.c   | 107 +++++++++++++++++++++++++++++
>  drivers/thermal/qcom/tsens-common.c | 130 ++++++++++++++++++++++++++++++++++++

Just a small comment on organization, does it make sense to move tsens-common
addition to the first patch, and then leave this patch only with the
support for 8916 (like you did for the other chips)?

>  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/Makefile b/drivers/thermal/qcom/Makefile
> index 401069b..05c98e4 100644
> --- a/drivers/thermal/qcom/Makefile
> +++ b/drivers/thermal/qcom/Makefile
> @@ -1,2 +1,2 @@
>  obj-$(CONFIG_QCOM_TSENS)	+= qcom_tsens.o
> -qcom_tsens-y			+= tsens.o
> +qcom_tsens-y			+= tsens.o tsens-common.o tsens-8916.o
> diff --git a/drivers/thermal/qcom/tsens-8916.c b/drivers/thermal/qcom/tsens-8916.c
> new file mode 100644
> index 0000000..a69aea3
> --- /dev/null
> +++ b/drivers/thermal/qcom/tsens-8916.c
> @@ -0,0 +1,107 @@
> +/*
> + * 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 "tsens.h"
> +
> +/* eeprom layout data for 8916 */
> +#define BASE0_MASK	0x0000007f
> +#define BASE1_MASK	0xfe000000
> +#define BASE0_SHIFT	0
> +#define BASE1_SHIFT	25
> +
> +#define S0_P1_MASK	0x00000f80
> +#define S1_P1_MASK	0x003e0000
> +#define S2_P1_MASK	0xf8000000
> +#define S3_P1_MASK	0x000003e0
> +#define S4_P1_MASK	0x000f8000
> +
> +#define S0_P2_MASK	0x0001f000
> +#define S1_P2_MASK	0x07c00000
> +#define S2_P2_MASK	0x0000001f
> +#define S3_P2_MASK	0x00007c00
> +#define S4_P2_MASK	0x01f00000
> +
> +#define S0_P1_SHIFT	7
> +#define S1_P1_SHIFT	17
> +#define S2_P1_SHIFT	27
> +#define S3_P1_SHIFT	5
> +#define S4_P1_SHIFT	15
> +
> +#define S0_P2_SHIFT	12
> +#define S1_P2_SHIFT	22
> +#define S2_P2_SHIFT	0
> +#define S3_P2_SHIFT	10
> +#define S4_P2_SHIFT	20
> +
> +#define CAL_SEL_MASK	0xe0000000
> +#define CAL_SEL_SHIFT	29
> +
> +static int calibrate_8916(struct tsens_device *tmdev)
> +{
> +	int base0 = 0, base1 = 0, i;
> +	u32 p1[5], p2[5];
> +	int mode = 0;
> +	u32 *qfprom_cdata, *qfprom_csel;
> +
> +	qfprom_cdata = (u32 *)qfprom_read(tmdev->dev, "calib");
> +	if (IS_ERR(qfprom_cdata))
> +		return PTR_ERR(qfprom_cdata);
> +
> +	qfprom_csel = (u32 *)qfprom_read(tmdev->dev, "calib_sel");
> +	if (IS_ERR(qfprom_csel))
> +		return PTR_ERR(qfprom_csel);
> +
> +	mode = (qfprom_csel[0] & CAL_SEL_MASK) >> CAL_SEL_SHIFT;
> +	dev_dbg(tmdev->dev, "calibration mode is %d\n", mode);
> +
> +	switch (mode) {
> +	case TWO_PT_CALIB:
> +		base1 = (qfprom_cdata[1] & BASE1_MASK) >> BASE1_SHIFT;
> +		p2[0] = (qfprom_cdata[0] & S0_P2_MASK) >> S0_P2_SHIFT;
> +		p2[1] = (qfprom_cdata[0] & S1_P2_MASK) >> S1_P2_SHIFT;
> +		p2[2] = (qfprom_cdata[1] & S2_P2_MASK) >> S2_P2_SHIFT;
> +		p2[3] = (qfprom_cdata[1] & S3_P2_MASK) >> S3_P2_SHIFT;
> +		p2[4] = (qfprom_cdata[1] & S4_P2_MASK) >> S4_P2_SHIFT;
> +		for (i = 0; i < tmdev->num_sensors; i++)
> +			p2[i] = ((base1 + p2[i]) << 3);
> +		/* Fall through */
> +	case ONE_PT_CALIB2:
> +		base0 = (qfprom_cdata[0] & BASE0_MASK);
> +		p1[0] = (qfprom_cdata[0] & S0_P1_MASK) >> S0_P1_SHIFT;
> +		p1[1] = (qfprom_cdata[0] & S1_P1_MASK) >> S1_P1_SHIFT;
> +		p1[2] = (qfprom_cdata[0] & S2_P1_MASK) >> S2_P1_SHIFT;
> +		p1[3] = (qfprom_cdata[1] & S3_P1_MASK) >> S3_P1_SHIFT;
> +		p1[4] = (qfprom_cdata[1] & S4_P1_MASK) >> S4_P1_SHIFT;
> +		for (i = 0; i < tmdev->num_sensors; i++)
> +			p1[i] = (((base0) + p1[i]) << 3);
> +		break;
> +	default:
> +		for (i = 0; i < tmdev->num_sensors; i++) {
> +			p1[i] = 500;
> +			p2[i] = 780;
> +		}
> +		break;
> +	}
> +
> +	compute_intercept_slope(tmdev, p1, p2, mode);
> +
> +	return 0;

Can calibration fail ? In which cases?

> +}
> +
> +const struct tsens_ops ops_8916 = {
> +	.init		= init_common,
> +	.calibrate	= calibrate_8916,
> +	.get_temp	= get_temp_common,
> +};
> 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);
nip: add a blank line here.
> +	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;
> +}
> +
> +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);

Should this function be marked as __init so devm_* works?

> +	if (!tmdev->map)
> +		return -ENODEV;

Should you do iounmap?

> +
> +	return 0;
> +}
> diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
> index 87f5215..3d49293 100644
> --- a/drivers/thermal/qcom/tsens.c
> +++ b/drivers/thermal/qcom/tsens.c
> @@ -65,6 +65,7 @@ static SIMPLE_DEV_PM_OPS(tsens_pm_ops, tsens_suspend, tsens_resume);
>  static const struct of_device_id tsens_table[] = {
>  	{
>  		.compatible = "qcom,msm8916-tsens",
> +		.data = &ops_8916,
>  	}, {
>  		.compatible = "qcom,msm8974-tsens",
>  	},
> diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
> index f0fc353..0923822 100644
> --- a/drivers/thermal/qcom/tsens.h
> +++ b/drivers/thermal/qcom/tsens.h
> @@ -13,6 +13,10 @@
>  #ifndef __QCOM_TSENS_H__
>  #define __QCOM_TSENS_H__
>  
> +#define ONE_PT_CALIB		0x1
> +#define ONE_PT_CALIB2		0x2
> +#define TWO_PT_CALIB		0x3
> +
>  struct tsens_device;
>  
>  struct tsens_sensor {
> @@ -55,4 +59,11 @@ struct tsens_device {
>  	struct tsens_sensor		sensor[0];
>  };
>  
> +char *qfprom_read(struct device *, const char *);
> +void compute_intercept_slope(struct tsens_device *, u32 *, u32 *, u32);
> +int init_common(struct tsens_device *);
> +int get_temp_common(struct tsens_device *, int, int *);
> +
> +extern const struct tsens_ops ops_8916;
> +
>  #endif /* __QCOM_TSENS_H__ */
> -- 
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> of Code Aurora Forum, hosted by The Linux Foundation
>