drivers/thermal/ti-bandgap.c

/*
 * TI Bandgap temperature sensor driver
 *
 * Copyright (C) 2017 Texas Instruments Incorporated - http://www.ti.com/
 *
 * 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.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Taken from Linux v4.9 (drivers/thermal/ti-soc-thermal/ti-bandgap.c)
 * and ported to uboot.
 *
 */

#include <asm/io.h>
#include <dm.h>
#include <thermal.h>

#define CTRL_CORE_TEMP_SENSOR_MPU	0
#define DRA752_ADC_START_VALUE		540

struct ti_bandgap {
	ulong			base;
	int			temperature;	/* in mili degree celsius */
};

/*
 * DRA752 : Temperature values in milli degree celsius
 * ADC code values from 540 to 945
 */
static int dra752_adc_to_temp[] = {
	/* Index 540 - 549 */
	-40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200,
	-37800,
	/* Index 550 - 559 */
	-37400, -37000, -36600, -36200, -35800, -35300, -34700, -34200, -33800,
	-33400,
	/* Index 560 - 569 */
	-33000, -32600, -32200, -31800, -31400, -31000, -30600, -30200, -29800,
	-29400,
	/* Index 570 - 579 */
	-29000, -28600, -28200, -27700, -27100, -26600, -26200, -25800, -25400,
	-25000,
	/* Index 580 - 589 */
	-24600, -24200, -23800, -23400, -23000, -22600, -22200, -21800, -21400,
	-21000,
	/* Index 590 - 599 */
	-20500, -19900, -19400, -19000, -18600, -18200, -17800, -17400, -17000,
	-16600,
	/* Index 600 - 609 */
	-16200, -15800, -15400, -15000, -14600, -14200, -13800, -13400, -13000,
	-12500,
	/* Index 610 - 619 */
	-11900, -11400, -11000, -10600, -10200, -9800, -9400, -9000, -8600,
	-8200,
	/* Index 620 - 629 */
	-7800, -7400, -7000, -6600, -6200, -5800, -5400, -5000, -4500,
	-3900,
	/* Index 630 - 639 */
	-3400, -3000, -2600, -2200, -1800, -1400, -1000, -600, -200,
	200,
	/* Index 640 - 649 */
	600, 1000, 1400, 1800, 2200, 2600, 3000, 3400, 3900,
	4500,
	/* Index 650 - 659 */
	5000, 5400, 5800, 6200, 6600, 7000, 7400, 7800, 8200,
	8600,
	/* Index 660 - 669 */
	9000, 9400, 9800, 10200, 10600, 11000, 11400, 11800, 12200,
	12700,
	/* Index 670 - 679 */
	13300, 13800, 14200, 14600, 15000, 15400, 15800, 16200, 16600,
	17000,
	/* Index 680 - 689 */
	17400, 17800, 18200, 18600, 19000, 19400, 19800, 20200, 20600,
	21000,
	/* Index 690 - 699 */
	21400, 21900, 22500, 23000, 23400, 23800, 24200, 24600, 25000,
	25400,
	/* Index 700 - 709 */
	25800, 26200, 26600, 27000, 27400, 27800, 28200, 28600, 29000,
	29400,
	/* Index 710 - 719 */
	29800, 30200, 30600, 31000, 31400, 31900, 32500, 33000, 33400,
	33800,
	/* Index 720 - 729 */
	34200, 34600, 35000, 35400, 35800, 36200, 36600, 37000, 37400,
	37800,
	/* Index 730 - 739 */
	38200, 38600, 39000, 39400, 39800, 40200, 40600, 41000, 41400,
	41800,
	/* Index 740 - 749 */
	42200, 42600, 43100, 43700, 44200, 44600, 45000, 45400, 45800,
	46200,
	/* Index 750 - 759 */
	46600, 47000, 47400, 47800, 48200, 48600, 49000, 49400, 49800,
	50200,
	/* Index 760 - 769 */
	50600, 51000, 51400, 51800, 52200, 52600, 53000, 53400, 53800,
	54200,
	/* Index 770 - 779 */
	54600, 55000, 55400, 55900, 56500, 57000, 57400, 57800, 58200,
	58600,
	/* Index 780 - 789 */
	59000, 59400, 59800, 60200, 60600, 61000, 61400, 61800, 62200,
	62600,
	/* Index 790 - 799 */
	63000, 63400, 63800, 64200, 64600, 65000, 65400, 65800, 66200,
	66600,
	/* Index 800 - 809 */
	67000, 67400, 67800, 68200, 68600, 69000, 69400, 69800, 70200,
	70600,
	/* Index 810 - 819 */
	71000, 71500, 72100, 72600, 73000, 73400, 73800, 74200, 74600,
	75000,
	/* Index 820 - 829 */
	75400, 75800, 76200, 76600, 77000, 77400, 77800, 78200, 78600,
	79000,
	/* Index 830 - 839 */
	79400, 79800, 80200, 80600, 81000, 81400, 81800, 82200, 82600,
	83000,
	/* Index 840 - 849 */
	83400, 83800, 84200, 84600, 85000, 85400, 85800, 86200, 86600,
	87000,
	/* Index 850 - 859 */
	87400, 87800, 88200, 88600, 89000, 89400, 89800, 90200, 90600,
	91000,
	/* Index 860 - 869 */
	91400, 91800, 92200, 92600, 93000, 93400, 93800, 94200, 94600,
	95000,
	/* Index 870 - 879 */
	95400, 95800, 96200, 96600, 97000, 97500, 98100, 98600, 99000,
	99400,
	/* Index 880 - 889 */
	99800, 100200, 100600, 101000, 101400, 101800, 102200, 102600, 103000,
	103400,
	/* Index 890 - 899 */
	103800, 104200, 104600, 105000, 105400, 105800, 106200, 106600, 107000,
	107400,
	/* Index 900 - 909 */
	107800, 108200, 108600, 109000, 109400, 109800, 110200, 110600, 111000,
	111400,
	/* Index 910 - 919 */
	111800, 112200, 112600, 113000, 113400, 113800, 114200, 114600, 115000,
	115400,
	/* Index 920 - 929 */
	115800, 116200, 116600, 117000, 117400, 117800, 118200, 118600, 119000,
	119400,
	/* Index 930 - 939 */
	119800, 120200, 120600, 121000, 121400, 121800, 122200, 122600, 123000,
	123400,
	/* Index 940 - 945 */
	123800, 124200, 124600, 124900, 125000, 125000,
};

static int ti_bandgap_get_temp(struct udevice *dev,  int *temp)
{
	struct ti_bandgap *bgp = dev_get_priv(dev);

	bgp->temperature = 0x3ff & readl(bgp->base + CTRL_CORE_TEMP_SENSOR_MPU);
	*temp = dra752_adc_to_temp[bgp->temperature - DRA752_ADC_START_VALUE];

	return 0;
}

static struct dm_thermal_ops ti_thermal_ops = {
	.get_temp	= ti_bandgap_get_temp,
};

static int ti_bandgap_probe(struct udevice *dev)
{
	struct ti_bandgap *bgp = dev_get_priv(dev);

	bgp->base = devfdt_get_addr_index(dev, 1);

	return 0;
}

static const struct udevice_id of_ti_bandgap_match[] = {
	{
		.compatible = "ti,dra752-bandgap",
	},
	{},
};

U_BOOT_DRIVER(ti_bandgap_thermal) = {
	.name	= "ti_bandgap_thermal",
	.id	= UCLASS_THERMAL,
	.ops	= &ti_thermal_ops,
	.probe	= ti_bandgap_probe,
	.of_match = of_ti_bandgap_match,
	.priv_auto_alloc_size = sizeof(struct ti_bandgap),
};