[PATCH v7 4/4] thermal: Add Tegra SOCTHERM thermal management driver

[Mikko Perttunen <mikko.perttunen@kapsi.fi>]

From: Mikko Perttunen <mperttunen@nvidia.com>

This adds support for the Tegra SOCTHERM thermal sensing and management
system found in the Tegra124 system-on-chip. This initial driver supports
temperature polling for four thermal zones.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
v7: bunch of style fixes

 drivers/thermal/Kconfig          |  10 +
 drivers/thermal/Makefile         |   1 +
 drivers/thermal/tegra_soctherm.c | 473 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 484 insertions(+)
 create mode 100644 drivers/thermal/tegra_soctherm.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 693208e..fd9d049 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -175,6 +175,16 @@ config ARMADA_THERMAL
 	  Enable this option if you want to have support for thermal management
 	  controller present in Armada 370 and Armada XP SoC.
 
+config TEGRA_SOCTHERM
+	tristate "Tegra SOCTHERM thermal management"
+	depends on ARCH_TEGRA
+	help
+	  Enable this option for integrated thermal management support on NVIDIA
+	  Tegra124 systems-on-chip. The driver supports four thermal zones
+	  (CPU, GPU, MEM, PLLX). Cooling devices can be bound to the thermal
+	  zones to manage temperatures. This option is also required for the
+	  emergency thermal reset (thermtrip) feature to function.
+
 config DB8500_CPUFREQ_COOLING
 	tristate "DB8500 cpufreq cooling"
 	depends on ARCH_U8500
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 31e232f..f0b94d5 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_INTEL_SOC_DTS_THERMAL)	+= intel_soc_dts_thermal.o
 obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
 obj-$(CONFIG_ACPI_INT3403_THERMAL)	+= int3403_thermal.o
 obj-$(CONFIG_ST_THERMAL)	+= st/
+obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra_soctherm.o
diff --git a/drivers/thermal/tegra_soctherm.c b/drivers/thermal/tegra_soctherm.c
new file mode 100644
index 0000000..70f7e9e
--- /dev/null
+++ b/drivers/thermal/tegra_soctherm.c
@@ -0,0 +1,473 @@
+/*
+ * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Author:
+ *	Mikko Perttunen <mperttunen@nvidia.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/thermal.h>
+
+#include <soc/tegra/fuse.h>
+
+#define SENSOR_CONFIG0				0
+#define SENSOR_CONFIG0_STOP			BIT(0)
+#define SENSOR_CONFIG0_TALL_SHIFT		8
+#define SENSOR_CONFIG0_TCALC_OVER		BIT(4)
+#define SENSOR_CONFIG0_OVER			BIT(3)
+#define SENSOR_CONFIG0_CPTR_OVER		BIT(2)
+
+#define SENSOR_CONFIG1				4
+#define SENSOR_CONFIG1_TSAMPLE_SHIFT		0
+#define SENSOR_CONFIG1_TIDDQ_EN_SHIFT		15
+#define SENSOR_CONFIG1_TEN_COUNT_SHIFT		24
+#define SENSOR_CONFIG1_TEMP_ENABLE		BIT(31)
+
+#define SENSOR_CONFIG2				8
+#define SENSOR_CONFIG2_THERMA_SHIFT		16
+#define SENSOR_CONFIG2_THERMB_SHIFT		0
+
+#define SENSOR_PDIV				0x1c0
+#define SENSOR_PDIV_T124			0x8888
+#define SENSOR_HOTSPOT_OFF			0x1c4
+#define SENSOR_HOTSPOT_OFF_T124			0x00060600
+#define SENSOR_TEMP1				0x1c8
+#define SENSOR_TEMP2				0x1cc
+
+#define SENSOR_TEMP_MASK			0xffff
+#define READBACK_VALUE_MASK			0xff00
+#define READBACK_VALUE_SHIFT			8
+#define READBACK_ADD_HALF			BIT(7)
+#define READBACK_NEGATE				BIT(1)
+
+#define FUSE_TSENSOR8_CALIB			0x180
+#define FUSE_SPARE_REALIGNMENT_REG_0		0x1fc
+
+#define FUSE_TSENSOR_CALIB_CP_TS_BASE_MASK	0x1fff
+#define FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK	(0x1fff << 13)
+#define FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT	13
+
+#define FUSE_TSENSOR8_CALIB_CP_TS_BASE_MASK	0x3ff
+#define FUSE_TSENSOR8_CALIB_FT_TS_BASE_MASK	(0x7ff << 10)
+#define FUSE_TSENSOR8_CALIB_FT_TS_BASE_SHIFT	10
+
+#define FUSE_SPARE_REALIGNMENT_REG_SHIFT_CP_MASK 0x3f
+#define FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_MASK (0x1f << 21)
+#define FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_SHIFT 21
+
+#define NOMINAL_CALIB_FT_T124			105
+#define NOMINAL_CALIB_CP_T124			25
+
+struct tegra_tsensor_configuration {
+	u32 tall, tsample, tiddq_en, ten_count, pdiv, tsample_ate, pdiv_ate;
+};
+
+struct tegra_tsensor {
+	const struct tegra_tsensor_configuration *config;
+	u32 base, calib_fuse_offset;
+	/* Correction values used to modify values read from calibration fuses */
+	s32 fuse_corr_alpha, fuse_corr_beta;
+};
+
+struct tegra_thermctl_zone {
+	void __iomem *reg;
+	unsigned int shift;
+};
+
+static const struct tegra_tsensor_configuration t124_tsensor_config = {
+	.tall = 16300,
+	.tsample = 120,
+	.tiddq_en = 1,
+	.ten_count = 1,
+	.pdiv = 8,
+	.tsample_ate = 480,
+	.pdiv_ate = 8
+};
+
+static const struct tegra_tsensor t124_tsensors[] = {
+	{
+		.config = &t124_tsensor_config,
+		.base = 0xc0,
+		.calib_fuse_offset = 0x098,
+		.fuse_corr_alpha = 1135400,
+		.fuse_corr_beta = -6266900,
+	},
+	{
+		.config = &t124_tsensor_config,
+		.base = 0xe0,
+		.calib_fuse_offset = 0x084,
+		.fuse_corr_alpha = 1122220,
+		.fuse_corr_beta = -5700700,
+	},
+	{
+		.config = &t124_tsensor_config,
+		.base = 0x100,
+		.calib_fuse_offset = 0x088,
+		.fuse_corr_alpha = 1127000,
+		.fuse_corr_beta = -6768200,
+	},
+	{
+		.config = &t124_tsensor_config,
+		.base = 0x120,
+		.calib_fuse_offset = 0x12c,
+		.fuse_corr_alpha = 1110900,
+		.fuse_corr_beta = -6232000,
+	},
+	{
+		.config = &t124_tsensor_config,
+		.base = 0x140,
+		.calib_fuse_offset = 0x158,
+		.fuse_corr_alpha = 1122300,
+		.fuse_corr_beta = -5936400,
+	},
+	{
+		.config = &t124_tsensor_config,
+		.base = 0x160,
+		.calib_fuse_offset = 0x15c,
+		.fuse_corr_alpha = 1145700,
+		.fuse_corr_beta = -7124600,
+	},
+	{
+		.config = &t124_tsensor_config,
+		.base = 0x180,
+		.calib_fuse_offset = 0x154,
+		.fuse_corr_alpha = 1120100,
+		.fuse_corr_beta = -6000500,
+	},
+	{
+		.config = &t124_tsensor_config,
+		.base = 0x1a0,
+		.calib_fuse_offset = 0x160,
+		.fuse_corr_alpha = 1106500,
+		.fuse_corr_beta = -6729300,
+	},
+};
+
+struct tegra_soctherm {
+	struct reset_control *reset;
+	struct clk *clock_tsensor;
+	struct clk *clock_soctherm;
+	void __iomem *regs;
+
+	struct thermal_zone_device *thermctl_tzs[4];
+};
+
+struct tsensor_shared_calibration {
+	u32 base_cp, base_ft;
+	u32 actual_temp_cp, actual_temp_ft;
+};
+
+static int calculate_shared_calibration(struct tsensor_shared_calibration *r)
+{
+	u32 val, shifted_cp, shifted_ft;
+	int err;
+
+	err = tegra_fuse_readl(FUSE_TSENSOR8_CALIB, &val);
+	if (err)
+		return err;
+	r->base_cp = val & FUSE_TSENSOR8_CALIB_CP_TS_BASE_MASK;
+	r->base_ft = (val & FUSE_TSENSOR8_CALIB_FT_TS_BASE_MASK)
+		>> FUSE_TSENSOR8_CALIB_FT_TS_BASE_SHIFT;
+	val = ((val & FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_MASK)
+		>> FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_SHIFT);
+	shifted_ft = sign_extend32(val, 4);
+
+	err = tegra_fuse_readl(FUSE_SPARE_REALIGNMENT_REG_0, &val);
+	if (err)
+		return err;
+	shifted_cp = sign_extend32(val, 5);
+
+	r->actual_temp_cp = 2 * NOMINAL_CALIB_CP_T124 + shifted_cp;
+	r->actual_temp_ft = 2 * NOMINAL_CALIB_FT_T124 + shifted_ft;
+
+	return 0;
+}
+
+static s64 div64_s64_precise(s64 a, s64 b)
+{
+	s64 r, al;
+
+	/* Scale up for increased precision division */
+	al = a << 16;
+
+	r = div64_s64(al * 2 + 1, 2 * b);
+	return r >> 16;
+}
+
+static int
+calculate_tsensor_calibration(const struct tegra_tsensor *sensor,
+			      const struct tsensor_shared_calibration *shared,
+			      u32 *calib)
+{
+	u32 val;
+	s32 actual_tsensor_ft, actual_tsensor_cp, delta_sens, delta_temp,
+	    mult, div;
+	s16 therma, thermb;
+	s64 tmp;
+	int err;
+
+	err = tegra_fuse_readl(sensor->calib_fuse_offset, &val);
+	if (err)
+		return err;
+
+	actual_tsensor_cp = (shared->base_cp * 64) + sign_extend32(val, 12);
+	val = (val & FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK)
+		>> FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT;
+	actual_tsensor_ft = (shared->base_ft * 32) + sign_extend32(val, 12);
+
+	delta_sens = actual_tsensor_ft - actual_tsensor_cp;
+	delta_temp = shared->actual_temp_ft - shared->actual_temp_cp;
+
+	mult = sensor->config->pdiv * sensor->config->tsample_ate;
+	div = sensor->config->tsample * sensor->config->pdiv_ate;
+
+	therma = div64_s64_precise((s64) delta_temp * (1LL << 13) * mult,
+				   (s64) delta_sens * div);
+
+	tmp = (s64)actual_tsensor_ft * shared->actual_temp_cp -
+	      (s64)actual_tsensor_cp * shared->actual_temp_ft;
+	thermb = div64_s64_precise(tmp, (s64)delta_sens);
+
+	therma = div64_s64_precise((s64)therma * sensor->fuse_corr_alpha,
+				   (s64)1000000LL);
+	thermb = div64_s64_precise((s64)thermb * sensor->fuse_corr_alpha +
+				   sensor->fuse_corr_beta, (s64)1000000LL);
+
+	*calib = ((u16)therma << SENSOR_CONFIG2_THERMA_SHIFT) |
+		 ((u16)thermb << SENSOR_CONFIG2_THERMB_SHIFT);
+
+	return 0;
+}
+
+static int enable_tsensor(struct tegra_soctherm *tegra,
+			  const struct tegra_tsensor *sensor,
+			  const struct tsensor_shared_calibration *shared)
+{
+	void __iomem *base = tegra->regs + sensor->base;
+	unsigned int val;
+	u32 calib;
+	int err;
+
+	err = calculate_tsensor_calibration(sensor, shared, &calib);
+	if (err)
+		return err;
+
+	val = sensor->config->tall << SENSOR_CONFIG0_TALL_SHIFT;
+	writel(val, base + SENSOR_CONFIG0);
+
+	val  = (sensor->config->tsample - 1) << SENSOR_CONFIG1_TSAMPLE_SHIFT;
+	val |= sensor->config->tiddq_en << SENSOR_CONFIG1_TIDDQ_EN_SHIFT;
+	val |= sensor->config->ten_count << SENSOR_CONFIG1_TEN_COUNT_SHIFT;
+	val |= SENSOR_CONFIG1_TEMP_ENABLE;
+	writel(val, base + SENSOR_CONFIG1);
+
+	writel(calib, base + SENSOR_CONFIG2);
+
+	return 0;
+}
+
+/*
+ * Translate from soctherm readback format to millicelsius.
+ * The soctherm readback format in bits is as follows:
+ *   TTTTTTTT H______N
+ * where T's contain the temperature in Celsius,
+ * H denotes an addition of 0.5 Celsius and N denotes negation
+ * of the final value.
+ */
+static long translate_temp(u16 val)
+{
+	long t;
+
+	t = ((val & READBACK_VALUE_MASK) >> READBACK_VALUE_SHIFT) * 1000;
+	if (val & READBACK_ADD_HALF)
+		t += 500;
+	if (val & READBACK_NEGATE)
+		t *= -1;
+
+	return t;
+}
+
+static int tegra_thermctl_get_temp(void *data, long *out_temp)
+{
+	struct tegra_thermctl_zone *zone = data;
+	u32 val;
+
+	val = (readl(zone->reg) >> zone->shift) & SENSOR_TEMP_MASK;
+	*out_temp = translate_temp(val);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_soctherm_of_match[] = {
+	{ .compatible = "nvidia,tegra124-soctherm" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra_soctherm_of_match);
+
+struct thermctl_zone_desc {
+	unsigned int offset;
+	unsigned int shift;
+};
+
+static const struct thermctl_zone_desc t124_thermctl_temp_zones[] = {
+	{ SENSOR_TEMP1, 16 },
+	{ SENSOR_TEMP2, 16 },
+	{ SENSOR_TEMP1, 0 },
+	{ SENSOR_TEMP2, 0 }
+};
+
+static int tegra_soctherm_probe(struct platform_device *pdev)
+{
+	struct tegra_soctherm *tegra;
+	struct thermal_zone_device *tz;
+	struct tsensor_shared_calibration shared_calib;
+	struct resource *res;
+	unsigned int i;
+	int err;
+
+	const struct tegra_tsensor *tsensors = t124_tsensors;
+
+	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
+	if (!tegra)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	tegra->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tegra->regs))
+		return PTR_ERR(tegra->regs);
+
+	tegra->reset = devm_reset_control_get(&pdev->dev, "soctherm");
+	if (IS_ERR(tegra->reset)) {
+		dev_err(&pdev->dev, "can't get soctherm reset\n");
+		return PTR_ERR(tegra->reset);
+	}
+
+	tegra->clock_tsensor = devm_clk_get(&pdev->dev, "tsensor");
+	if (IS_ERR(tegra->clock_tsensor)) {
+		dev_err(&pdev->dev, "can't get tsensor clock\n");
+		return PTR_ERR(tegra->clock_tsensor);
+	}
+
+	tegra->clock_soctherm = devm_clk_get(&pdev->dev, "soctherm");
+	if (IS_ERR(tegra->clock_soctherm)) {
+		dev_err(&pdev->dev, "can't get soctherm clock\n");
+		return PTR_ERR(tegra->clock_soctherm);
+	}
+
+	reset_control_assert(tegra->reset);
+
+	err = clk_prepare_enable(tegra->clock_soctherm);
+	if (err)
+		return err;
+
+	err = clk_prepare_enable(tegra->clock_tsensor);
+	if (err) {
+		clk_disable_unprepare(tegra->clock_soctherm);
+		return err;
+	}
+
+	reset_control_deassert(tegra->reset);
+
+	/* Initialize raw sensors */
+
+	err = calculate_shared_calibration(&shared_calib);
+	if (err)
+		goto disable_clocks;
+
+	for (i = 0; i < ARRAY_SIZE(t124_tsensors); ++i) {
+		err = enable_tsensor(tegra, tsensors + i, &shared_calib);
+		if (err)
+			goto disable_clocks;
+	}
+
+	writel(SENSOR_PDIV_T124, tegra->regs + SENSOR_PDIV);
+	writel(SENSOR_HOTSPOT_OFF_T124, tegra->regs + SENSOR_HOTSPOT_OFF);
+
+	/* Initialize thermctl sensors */
+
+	for (i = 0; i < ARRAY_SIZE(tegra->thermctl_tzs); ++i) {
+		struct tegra_thermctl_zone *zone =
+			devm_kzalloc(&pdev->dev, sizeof(*zone), GFP_KERNEL);
+		if (!zone) {
+			err = -ENOMEM;
+			goto unregister_tzs;
+		}
+
+		zone->reg = tegra->regs + t124_thermctl_temp_zones[i].offset;
+		zone->shift = t124_thermctl_temp_zones[i].shift;
+
+		tz = thermal_zone_of_sensor_register(&pdev->dev, i, zone,
+						     tegra_thermctl_get_temp,
+						     NULL);
+		if (IS_ERR(tz)) {
+			err = PTR_ERR(tz);
+			dev_err(&pdev->dev, "failed to register sensor: %d\n",
+				err);
+			goto unregister_tzs;
+		}
+
+		tegra->thermctl_tzs[i] = tz;
+	}
+
+	return 0;
+
+unregister_tzs:
+	while (i--)
+		thermal_zone_of_sensor_unregister(&pdev->dev,
+						  tegra->thermctl_tzs[i]);
+
+disable_clocks:
+	clk_disable_unprepare(tegra->clock_tsensor);
+	clk_disable_unprepare(tegra->clock_soctherm);
+
+	return err;
+}
+
+static int tegra_soctherm_remove(struct platform_device *pdev)
+{
+	struct tegra_soctherm *tegra = platform_get_drvdata(pdev);
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tegra->thermctl_tzs); ++i) {
+		thermal_zone_of_sensor_unregister(&pdev->dev,
+						  tegra->thermctl_tzs[i]);
+	}
+
+	clk_disable_unprepare(tegra->clock_tsensor);
+	clk_disable_unprepare(tegra->clock_soctherm);
+
+	return 0;
+}
+
+static struct platform_driver tegra_soctherm_driver = {
+	.probe = tegra_soctherm_probe,
+	.remove = tegra_soctherm_remove,
+	.driver = {
+		.name = "tegra-soctherm",
+		.of_match_table = tegra_soctherm_of_match,
+	},
+};
+module_platform_driver(tegra_soctherm_driver);
+
+MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra SOCTHERM thermal management driver");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0