thermal: ti-bandgap: Add support for temperature sensor

The dra7xx series of SOCs contain a temperature sensor and an associated analog-to-digital converter (ADC) which produces an output which is proportional to the SOC temperature. Add support for this temperature sensor. Signed-off-by: Faiz Abbas <faiz_abbas@ti.com> Reviewed-by: Simon Glass <sjg@chromium.org>
7 years ago · 8502f9f6d7
parent 5ad1fec6ed
commit 8502f9f6d7
6 changed files with 249 additions and 0 deletions
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@ -605,6 +605,14 @@ config SPL_SPI_SUPPORT
 	  enable SPI drivers that are needed for other purposes also, such
 	  as a SPI PMIC.

+config SPL_THERMAL
+	bool "Driver support for thermal devices"
+	help
+	  Enable support for temperature-sensing devices. Some SoCs have on-chip
+	  temperature sensors to permit warnings, speed throttling or even
+	  automatic power-off when the temperature gets too high or low. Other
+	  devices may be discrete but connected on a suitable bus.
+
 config SPL_USB_HOST_SUPPORT
 	bool "Support USB host drivers"
 	help
--- a/doc/device-tree-bindings/thermal/ti_soc_thermal.txt
+++ b/doc/device-tree-bindings/thermal/ti_soc_thermal.txt
@ -0,0 +1,35 @@
+* Texas Instrument dra7xx SCM bandgap bindings
+
+In the System Control Module, SoC supplies a voltage reference
+and a temperature sensor feature that are gathered in the band
+gap voltage and temperature sensor (VBGAPTS) module. The band
+gap provides current and voltage reference for its internal
+circuits and other analog IP blocks. The analog-to-digital
+converter (ADC) produces an output value that is proportional
+to the silicon temperature.
+
+Required properties:
+- compatible : Should be:
+  - "ti,dra752-bandgap"
+- interrupts : this entry should indicate which interrupt line
+the talert signal is routed to;
+- regs : this is specific to each bandgap version, because
+the mapping may change from soc to soc, apart from depending
+on available features.
+
+Optional:
+- gpios : this entry should be used to inform which GPIO
+line the tshut signal is routed to. The informed GPIO will
+be treated as an IRQ;
+
+Example:
+bandgap {
+	reg = <0x4a0021e0 0xc
+		0x4a00232c 0xc
+		0x4a002380 0x2c
+		0x4a0023C0 0x3c
+		0x4a002564 0x8
+		0x4a002574 0x50>;
+	compatible = "ti,dra752-bandgap";
+	interrupts = <0 126 4>; /* talert */
+};
--- a/drivers/Makefile
+++ b/drivers/Makefile
@ -50,6 +50,7 @@ obj-$(CONFIG_SPL_SATA_SUPPORT) += ata/ scsi/
 obj-$(CONFIG_SPL_USB_HOST_SUPPORT) += block/
 obj-$(CONFIG_SPL_MMC_SUPPORT) += block/
 obj-$(CONFIG_SPL_FPGA_SUPPORT) += fpga/
+obj-$(CONFIG_SPL_THERMAL) += thermal/

 endif
 endif
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@ -17,4 +17,10 @@ config IMX_THERMAL
          cpufreq is used as the cooling device to throttle CPUs when the
          passive trip is crossed.

+config TI_DRA7_THERMAL
+        bool "Temperature sensor driver for TI dra7xx SOCs"
+        help
+	 Enable thermal support for for the Texas Instruments DRA752 SoC family.
+	 The driver supports reading CPU temperature.
+
 endif # if DM_THERMAL
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@ -7,3 +7,4 @@

 obj-$(CONFIG_DM_THERMAL) += thermal-uclass.o
 obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o
+obj-$(CONFIG_TI_DRA7_THERMAL) += ti-bandgap.o
--- a/drivers/thermal/ti-bandgap.c
+++ b/drivers/thermal/ti-bandgap.c
@ -0,0 +1,198 @@
+/*
+ * 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),
+};