[PATCH 1/2] thermal: k3-j72xx-bandgap: Add support for vtm

Udit Kumar u-kumar1 at ti.com
Fri Sep 1 08:14:59 CEST 2023


Add support for VTM (Voltage and Thermal Manager), which
is part of TI's K3 series SOC.

Signed-off-by: Udit Kumar <u-kumar1 at ti.com>
---
 drivers/thermal/Kconfig            |   6 +
 drivers/thermal/Makefile           |   1 +
 drivers/thermal/k3_j72xx_bandgap.c | 539 +++++++++++++++++++++++++++++
 3 files changed, 546 insertions(+)
 create mode 100644 drivers/thermal/k3_j72xx_bandgap.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 681b621760..5ecd916365 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -35,6 +35,12 @@ config IMX_TMU
 	  The boot is hold to the cool device to throttle CPUs when the
 	  passive trip is crossed
 
+config TI_K3_THERMAL
+        bool "Temperature sensor driver for TI K3 j7xx SOCs"
+        help
+	 Enable thermal support for the Texas Instruments TI K3 j7xx family.
+	 The driver supports reading CPU temperature.
+
 config TI_DRA7_THERMAL
         bool "Temperature sensor driver for TI dra7xx SOCs"
         help
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 8acc7d20cb..e2a6d9f877 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -8,4 +8,5 @@ obj-$(CONFIG_SANDBOX) += thermal_sandbox.o
 obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o
 obj-$(CONFIG_IMX_SCU_THERMAL) += imx_scu_thermal.o
 obj-$(CONFIG_TI_DRA7_THERMAL) += ti-bandgap.o
+obj-$(CONFIG_TI_K3_THERMAL) += k3_j72xx_bandgap.o
 obj-$(CONFIG_IMX_TMU) += imx_tmu.o
diff --git a/drivers/thermal/k3_j72xx_bandgap.c b/drivers/thermal/k3_j72xx_bandgap.c
new file mode 100644
index 0000000000..5524bb5c9a
--- /dev/null
+++ b/drivers/thermal/k3_j72xx_bandgap.c
@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI Bandgap temperature sensor driver for J72XX SoC Family
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ *
+ * Taken from Linux v6.5 (drivers/thermal/k3_j72xx_bandgap.c)
+ * and ported to uboot
+ */
+
+#include <linux/math64.h>
+#include <dm.h>
+#include <dm/devres.h>
+#include <thermal.h>
+
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+
+#define K3_VTM_DEVINFO_PWR0_OFFSET		0x4
+#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK	0xf0
+#define K3_VTM_TMPSENS0_CTRL_OFFSET		0x300
+#define K3_VTM_MISC_CTRL_OFFSET			0xc
+#define K3_VTM_TMPSENS_STAT_OFFSET		0x8
+#define K3_VTM_ANYMAXT_OUTRG_ALERT_EN		0x1
+#define K3_VTM_MISC_CTRL2_OFFSET		0x10
+#define K3_VTM_TS_STAT_DTEMP_MASK		0x3ff
+#define K3_VTM_MAX_NUM_TS			8
+#define K3_VTM_TMPSENS_CTRL_SOC			BIT(5)
+#define K3_VTM_TMPSENS_CTRL_CLRZ		BIT(6)
+#define K3_VTM_TMPSENS_CTRL_CLKON_REQ		BIT(7)
+#define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN	BIT(11)
+
+#define K3_VTM_CORRECTION_TEMP_CNT		3
+
+#define MINUS40CREF				5
+#define PLUS30CREF				253
+#define PLUS125CREF				730
+#define PLUS150CREF				940
+
+#define TABLE_SIZE				1024
+#define MAX_TEMP				123000
+#define COOL_DOWN_TEMP				105000
+
+#define FACTORS_REDUCTION			13
+static int *derived_table;
+
+static u64 int_pow(u64 base, unsigned int exp)
+{
+	u64 result = 1;
+
+	while (exp) {
+		if (exp & 1)
+			result *= base;
+		exp >>= 1;
+		base *= base;
+	}
+
+	return result;
+}
+
+static int compute_value(int index, const s64 *factors, int nr_factors,
+			 int reduction)
+{
+	s64 value = 0;
+	int i;
+
+	for (i = 0; i < nr_factors; i++)
+		value += factors[i] * int_pow(index, i);
+
+	return (int)div64_s64(value, int_pow(10, reduction));
+}
+
+static void init_table(int factors_size, int *table, const s64 *factors)
+{
+	int i;
+
+	for (i = 0; i < TABLE_SIZE; i++)
+		table[i] = compute_value(i, factors, factors_size,
+					 FACTORS_REDUCTION);
+}
+
+/**
+ * struct err_values - structure containing error/reference values
+ * @refs: reference error values for -40C, 30C, 125C & 150C
+ * @errs: Actual error values for -40C, 30C, 125C & 150C read from the efuse
+ */
+struct err_values {
+	int refs[4];
+	int errs[4];
+};
+
+static void create_table_segments(struct err_values *err_vals, int seg,
+				  int *ref_table)
+{
+	int m = 0, c, num, den, i, err, idx1, idx2, err1, err2, ref1, ref2;
+
+	if (seg == 0)
+		idx1 = 0;
+	else
+		idx1 = err_vals->refs[seg];
+
+	idx2 = err_vals->refs[seg + 1];
+	err1 = err_vals->errs[seg];
+	err2 = err_vals->errs[seg + 1];
+	ref1 = err_vals->refs[seg];
+	ref2 = err_vals->refs[seg + 1];
+
+	/*
+	 * Calculate the slope with adc values read from the register
+	 * as the y-axis param and err in adc value as x-axis param
+	 */
+	num = ref2 - ref1;
+	den = err2 - err1;
+	if (den)
+		m = num / den;
+	c = ref2 - m * err2;
+
+	/*
+	 * Take care of divide by zero error if error values are same
+	 * Or when the slope is 0
+	 */
+	if (den != 0 && m != 0) {
+		for (i = idx1; i <= idx2; i++) {
+			err = (i - c) / m;
+			if (((i + err) < 0) || ((i + err) >= TABLE_SIZE))
+				continue;
+			derived_table[i] = ref_table[i + err];
+		}
+	} else { /* Constant error take care of divide by zero */
+		for (i = idx1; i <= idx2; i++) {
+			if (((i + err1) < 0) || ((i + err1) >= TABLE_SIZE))
+				continue;
+			derived_table[i] = ref_table[i + err1];
+		}
+	}
+}
+
+static int prep_lookup_table(struct err_values *err_vals, int *ref_table)
+{
+	int inc, i, seg;
+
+	/*
+	 * Fill up the lookup table under 3 segments
+	 * region -40C to +30C
+	 * region +30C to +125C
+	 * region +125C to +150C
+	 */
+	for (seg = 0; seg < 3; seg++)
+		create_table_segments(err_vals, seg, ref_table);
+
+	/* Get to the first valid temperature */
+	i = 0;
+	while (!derived_table[i])
+		i++;
+
+	/*
+	 * Get to the last zero index and back fill the temperature for
+	 * sake of continuity
+	 */
+	if (i) {
+		/* 300 milli celsius steps */
+		while (i--)
+			derived_table[i] = derived_table[i + 1] - 300;
+	}
+
+	/*
+	 * Fill the last trailing 0s which are unfilled with increments of
+	 * 100 milli celsius till 1023 code
+	 */
+	i = TABLE_SIZE - 1;
+	while (!derived_table[i])
+		i--;
+
+	i++;
+	inc = 1;
+	while (i < TABLE_SIZE) {
+		derived_table[i] = derived_table[i - 1] + inc * 100;
+		i++;
+	}
+
+	return 0;
+}
+
+struct k3_thermal_data;
+
+struct k3_j72xx_bandgap {
+	struct udevice *dev;
+	void __iomem *base;
+	void __iomem *cfg2_base;
+	struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
+};
+
+/* common data structures */
+struct k3_thermal_data {
+	struct k3_j72xx_bandgap *bgp;
+	u32 ctrl_offset;
+	u32 stat_offset;
+};
+
+static int two_cmp(int tmp, int mask)
+{
+	tmp = ~(tmp);
+	tmp &= mask;
+	tmp += 1;
+
+	/* Return negative value */
+	return (0 - tmp);
+}
+
+static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1,
+				       unsigned int s2)
+{
+	int d01 = abs(s0 - s1);
+	int d02 = abs(s0 - s2);
+	int d12 = abs(s1 - s2);
+
+	if (d01 <= d02 && d01 <= d12)
+		return (s0 + s1) / 2;
+
+	if (d02 <= d01 && d02 <= d12)
+		return (s0 + s2) / 2;
+
+	return (s1 + s2) / 2;
+}
+
+static inline int k3_bgp_read_temp(struct k3_j72xx_bandgap *bgp,
+				   int *temp)
+{
+	unsigned int dtemp, s0, s1, s2;
+
+	/*
+	 * Errata is applicable for am654 pg 1.0 silicon/J7ES. There
+	 * is a variation of the order for certain degree centigrade on AM654.
+	 * Work around that by getting the average of two closest
+	 * readings out of three readings everytime we want to
+	 * report temperatures.
+	 *
+	 * Errata workaround.
+	 */
+	s0 = readl(bgp->base + bgp->ts_data[0]->stat_offset) &
+		K3_VTM_TS_STAT_DTEMP_MASK;
+	s1 = readl(bgp->base + bgp->ts_data[0]->stat_offset) &
+		K3_VTM_TS_STAT_DTEMP_MASK;
+	s2 = readl(bgp->base + bgp->ts_data[0]->stat_offset) &
+		K3_VTM_TS_STAT_DTEMP_MASK;
+	dtemp = vtm_get_best_value(s0, s1, s2);
+
+	if (dtemp < 0 || dtemp >= TABLE_SIZE)
+		return -EINVAL;
+
+	*temp = derived_table[dtemp];
+
+	return 0;
+}
+
+/* Get temperature callback function for thermal zone */
+static int k3_thermal_get_temp(struct udevice *dev,  int *temp)
+{
+	struct k3_j72xx_bandgap *bgp = dev_get_priv(dev);
+
+	return k3_bgp_read_temp(bgp, temp);
+}
+
+static const struct dm_thermal_ops k3_of_thermal_ops = {
+	.get_temp = k3_thermal_get_temp,
+};
+
+static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
+{
+	int low = 0, high = TABLE_SIZE - 1, mid;
+
+	if (temp > 160000 || temp < -50000)
+		return -EINVAL;
+
+	/* Binary search to find the adc code */
+	while (low < (high - 1)) {
+		mid = (low + high) / 2;
+		if (temp <= derived_table[mid])
+			high = mid;
+		else
+			low = mid;
+	}
+
+	return mid;
+}
+
+static void get_efuse_values(int id, struct k3_thermal_data *data, int *err,
+			     void __iomem *fuse_base)
+{
+	int i, tmp, pow;
+	int ct_offsets[5][K3_VTM_CORRECTION_TEMP_CNT] = {
+		{ 0x0, 0x8, 0x4 },
+		{ 0x0, 0x8, 0x4 },
+		{ 0x0, -1,  0x4 },
+		{ 0x0, 0xC, -1 },
+		{ 0x0, 0xc, 0x8 }
+	};
+	int ct_bm[5][K3_VTM_CORRECTION_TEMP_CNT] = {
+		{ 0x3f, 0x1fe000, 0x1ff },
+		{ 0xfc0, 0x1fe000, 0x3fe00 },
+		{ 0x3f000, 0x7f800000, 0x7fc0000 },
+		{ 0xfc0000, 0x1fe0, 0x1f800000 },
+		{ 0x3f000000, 0x1fe000, 0x1ff0 }
+	};
+
+	for (i = 0; i < 3; i++) {
+		/* Extract the offset value using bit-mask */
+		if (ct_offsets[id][i] == -1 && i == 1) {
+			/* 25C offset Case of Sensor 2 split between 2 regs */
+			tmp = (readl(fuse_base + 0x8) & 0xE0000000) >> (29);
+			tmp |= ((readl(fuse_base + 0xC) & 0x1F) << 3);
+			pow = tmp & 0x80;
+		} else if (ct_offsets[id][i] == -1 && i == 2) {
+			/* 125C Case of Sensor 3 split between 2 regs */
+			tmp = (readl(fuse_base + 0x4) & 0xF8000000) >> (27);
+			tmp |= ((readl(fuse_base + 0x8) & 0xF) << 5);
+			pow = tmp & 0x100;
+		} else {
+			tmp = readl(fuse_base + ct_offsets[id][i]);
+			tmp &= ct_bm[id][i];
+			tmp = tmp >> __ffs(ct_bm[id][i]);
+
+			/* Obtain the sign bit pow*/
+			pow = ct_bm[id][i] >> __ffs(ct_bm[id][i]);
+			pow += 1;
+			pow /= 2;
+		}
+
+		/* Check for negative value */
+		if (tmp & pow) {
+			/* 2's complement value */
+			tmp = two_cmp(tmp, ct_bm[id][i] >> __ffs(ct_bm[id][i]));
+		}
+		err[i] = tmp;
+	}
+
+	/* Err value for 150C is set to 0 */
+	err[i] = 0;
+}
+
+static void print_look_up_table(struct udevice *dev, int *ref_table)
+{
+	int i;
+
+	debug("The contents of derived array\n");
+	debug("Code   Temperature\n");
+	for (i = 0; i < TABLE_SIZE; i++)
+		debug("%d       %d %d\n", i, derived_table[i], ref_table[i]);
+}
+
+struct k3_j72xx_bandgap_data {
+	const bool has_errata_i2128;
+};
+
+static int k3_j72xx_bandgap_probe(struct udevice *dev)
+{
+	int ret = 0, cnt, val, id;
+	int high_max, low_temp;
+	struct k3_j72xx_bandgap *bgp;
+	struct k3_thermal_data *data;
+	bool workaround_needed = false;
+	const struct k3_j72xx_bandgap_data *driver_data;
+	int *ref_table;
+	struct err_values err_vals;
+	void __iomem *fuse_base;
+
+	const s64 golden_factors[] = {
+		-490019999999999936,
+		3251200000000000,
+		-1705800000000,
+		603730000,
+		-92627,
+	};
+
+	const s64 pvt_wa_factors[] = {
+		-415230000000000000,
+		3126600000000000,
+		-1157800000000,
+	};
+	bgp = dev_get_priv(dev);
+	if (!bgp)
+		return -ENOMEM;
+
+	bgp->dev = dev;
+	bgp->base = (void __iomem *)devfdt_get_addr_index(dev, 0);
+	if (IS_ERR(bgp->base))
+		return PTR_ERR(bgp->base);
+
+	bgp->cfg2_base = (void __iomem *)devfdt_get_addr_index(dev, 1);
+	if (IS_ERR(bgp->cfg2_base))
+		return PTR_ERR(bgp->cfg2_base);
+
+	driver_data = (const struct k3_j72xx_bandgap_data *)dev_get_driver_data(dev);
+	if (driver_data)
+		workaround_needed = driver_data->has_errata_i2128;
+
+	/*
+	 * Some of TI's J721E SoCs require a software trimming procedure
+	 * for the temperature monitors to function properly. To determine
+	 * if this particular SoC is NOT affected, both bits in the
+	 * WKUP_SPARE_FUSE0[31:30] will be set (0xC0000000) indicating
+	 * when software trimming should NOT be applied.
+	 *
+	 * https://www.ti.com/lit/er/sprz455c/sprz455c.pdf
+	 */
+	if (workaround_needed) {
+		fuse_base = (void __iomem *)devfdt_get_addr_index(dev, 2);
+		if (IS_ERR(fuse_base))
+			return PTR_ERR(fuse_base);
+
+		if ((readl(fuse_base) & 0xc0000000) == 0xc0000000)
+			workaround_needed = false;
+	}
+
+	debug("Work around %sneeded\n", workaround_needed ? "" : "not ");
+
+	/* Get the sensor count in the VTM */
+	val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
+	cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
+	cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
+
+	data = devm_kcalloc(bgp->dev, cnt, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	ref_table = kzalloc(sizeof(*ref_table) * TABLE_SIZE, GFP_KERNEL);
+	if (!ref_table) {
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	derived_table = devm_kzalloc(bgp->dev, sizeof(*derived_table) * TABLE_SIZE,
+				     GFP_KERNEL);
+	if (!derived_table) {
+		ret = -ENOMEM;
+		goto err_free_ref_table;
+	}
+
+	if (!workaround_needed)
+		init_table(5, ref_table, golden_factors);
+	else
+		init_table(3, ref_table, pvt_wa_factors);
+
+	/* Register the thermal sensors */
+	for (id = 0; id < cnt; id++) {
+		data[id].bgp = bgp;
+		data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
+		data[id].stat_offset = data[id].ctrl_offset +
+					K3_VTM_TMPSENS_STAT_OFFSET;
+
+		if (workaround_needed) {
+			/* ref adc values for -40C, 30C & 125C respectively */
+			err_vals.refs[0] = MINUS40CREF;
+			err_vals.refs[1] = PLUS30CREF;
+			err_vals.refs[2] = PLUS125CREF;
+			err_vals.refs[3] = PLUS150CREF;
+			get_efuse_values(id, &data[id], err_vals.errs, fuse_base);
+		}
+
+		if (id == 0 && workaround_needed)
+			prep_lookup_table(&err_vals, ref_table);
+		else if (id == 0 && !workaround_needed)
+			memcpy(derived_table, ref_table, TABLE_SIZE * 4);
+
+		val = readl(data[id].bgp->cfg2_base + data[id].ctrl_offset);
+		val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
+			K3_VTM_TMPSENS_CTRL_SOC |
+			K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
+		writel(val, data[id].bgp->cfg2_base + data[id].ctrl_offset);
+
+		bgp->ts_data[id] = &data[id];
+	}
+
+	/*
+	 * Program TSHUT thresholds
+	 * Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
+	 * Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN  bit
+	 *         This is already taken care as per of init
+	 * Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN  bit
+	 */
+	high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
+	low_temp = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
+
+	writel((low_temp << 16) | high_max, data[0].bgp->cfg2_base +
+	       K3_VTM_MISC_CTRL2_OFFSET);
+	mdelay(100);
+	writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, data[0].bgp->cfg2_base +
+	       K3_VTM_MISC_CTRL_OFFSET);
+
+	print_look_up_table(dev, ref_table);
+	/*
+	 * Now that the derived_table has the appropriate look up values
+	 * Free up the ref_table
+	 */
+	kfree(ref_table);
+
+	return 0;
+
+err_free_ref_table:
+	kfree(ref_table);
+
+err_alloc:
+
+	return ret;
+}
+
+static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = {
+	.has_errata_i2128 = true,
+};
+
+static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j7200_data = {
+	.has_errata_i2128 = false,
+};
+
+static const struct  udevice_id of_k3_j72xx_bandgap_match[] = {
+	{
+		.compatible = "ti,j721e-vtm",
+		.data = (ulong)&k3_j72xx_bandgap_j721e_data,
+	},
+	{
+		.compatible = "ti,j7200-vtm",
+		.data = (ulong)&k3_j72xx_bandgap_j7200_data,
+	},
+	{ /* sentinel */ },
+};
+
+U_BOOT_DRIVER(ti_bandgap_thermal) = {
+	.name	= "ti_bandgap_thermal",
+	.id	= UCLASS_THERMAL,
+	.ops	= &k3_of_thermal_ops,
+	.probe	= k3_j72xx_bandgap_probe,
+	.of_match = of_k3_j72xx_bandgap_match,
+	.priv_auto	= sizeof(struct k3_j72xx_bandgap),
+};
-- 
2.34.1



More information about the U-Boot mailing list