Exynos5: TMU: Add driver for Thermal Management Unit

Adding Exynos Thermal Management Unit driver to monitor SOC
temperature and take actions corresponding to states of TMU.

Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

2 files changed, 305 insertions, 0 deletions

diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index 8c71901..1dac16a 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -25,6 +25,7 @@ include $(TOPDIR)/config.mk
 
 LIB	:= $(obj)libpower.o
 
+COBJS-$(CONFIG_EXYNOS_TMU)	+= exynos-tmu.o
 COBJS-$(CONFIG_FTPMU010_POWER)	+= ftpmu010.o
 COBJS-$(CONFIG_TPS6586X_POWER)	+= tps6586x.o
 COBJS-$(CONFIG_TWL4030_POWER)	+= twl4030.o
diff --git a/drivers/power/exynos-tmu.c b/drivers/power/exynos-tmu.c
new file mode 100644
index 0000000..d8313b1
--- /dev/null
+++ b/drivers/power/exynos-tmu.c
@@ -0,0 +1,304 @@
+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *      http://www.samsung.com
+ * Akshay Saraswat <akshay.s@samsung.com>
+ *
+ * EXYNOS - Thermal Management Unit
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <tmu.h>
+#include <asm/arch/tmu.h>
+
+#define TRIMINFO_RELOAD		1
+#define CORE_EN			1
+
+#define INTEN_RISE0		1
+#define INTEN_RISE1		(1 << 4)
+#define INTEN_RISE2		(1 << 8)
+#define INTEN_FALL0		(1 << 16)
+#define INTEN_FALL1		(1 << 20)
+#define INTEN_FALL2		(1 << 24)
+
+#define TRIM_INFO_MASK		0xff
+
+#define INTCLEAR_RISE0		1
+#define INTCLEAR_RISE1		(1 << 4)
+#define INTCLEAR_RISE2		(1 << 8)
+#define INTCLEAR_FALL0		(1 << 16)
+#define INTCLEAR_FALL1		(1 << 20)
+#define INTCLEAR_FALL2		(1 << 24)
+#define INTCLEARALL		(INTCLEAR_RISE0 | INTCLEAR_RISE1 | \
+				 INTCLEAR_RISE2 | INTCLEAR_FALL0 | \
+				 INTCLEAR_FALL1 | INTCLEAR_FALL2)
+
+/* Tmeperature threshold values for various thermal events */
+struct temperature_params {
+	/* minimum value in temperature code range */
+	unsigned int min_val;
+	/* maximum value in temperature code range */
+	unsigned int max_val;
+	/* temperature threshold to start warning */
+	unsigned int start_warning;
+	/* temperature threshold CPU tripping */
+	unsigned int start_tripping;
+};
+
+/* Pre-defined values and thresholds for calibration of current temperature */
+struct tmu_data {
+	/* pre-defined temperature thresholds */
+	struct temperature_params ts;
+	/* pre-defined efuse range minimum value */
+	unsigned int efuse_min_value;
+	/* pre-defined efuse value for temperature calibration */
+	unsigned int efuse_value;
+	/* pre-defined efuse range maximum value */
+	unsigned int efuse_max_value;
+	/* current temperature sensing slope */
+	unsigned int slope;
+};
+
+/* TMU device specific details and status */
+struct tmu_info {
+	/* base Address for the TMU */
+	unsigned tmu_base;
+	/* pre-defined values for calibration and thresholds */
+	struct tmu_data data;
+	/* value required for triminfo_25 calibration */
+	unsigned int te1;
+	/* value required for triminfo_85 calibration */
+	unsigned int te2;
+	/* Value for measured data calibration */
+	int dc_value;
+	/* enum value indicating status of the TMU */
+	int tmu_state;
+};
+
+/* Global struct tmu_info variable to store init values */
+static struct tmu_info gbl_info;
+
+/*
+ * Get current temperature code from register,
+ * then calculate and calibrate it's value
+ * in degree celsius.
+ *
+ * @return	current temperature of the chip as sensed by TMU
+ */
+static int get_cur_temp(struct tmu_info *info)
+{
+	int cur_temp;
+	struct exynos5_tmu_reg *reg = (struct exynos5_tmu_reg *)info->tmu_base;
+
+	/*
+	 * Temperature code range between min 25 and max 125.
+	 * May run more than once for first call as initial sensing
+	 * has not yet happened.
+	 */
+	do {
+		cur_temp = readl(&reg->current_temp) & 0xff;
+	} while (cur_temp == 0 && info->tmu_state == TMU_STATUS_NORMAL);
+
+	/* Calibrate current temperature */
+	cur_temp = cur_temp - info->te1 + info->dc_value;
+
+	return cur_temp;
+}
+
+/*
+ * Monitors status of the TMU device and exynos temperature
+ *
+ * @param temp	pointer to the current temperature value
+ * @return	enum tmu_status_t value, code indicating event to execute
+ */
+enum tmu_status_t tmu_monitor(int *temp)
+{
+	int cur_temp;
+	struct tmu_data *data = &gbl_info.data;
+
+	if (gbl_info.tmu_state == TMU_STATUS_INIT)
+		return TMU_STATUS_INIT;
+
+	/* Read current temperature of the SOC */
+	cur_temp = get_cur_temp(&gbl_info);
+	*temp = cur_temp;
+
+	/* Temperature code lies between min 25 and max 125 */
+	if (cur_temp >= data->ts.start_tripping &&
+			cur_temp <= data->ts.max_val) {
+		return TMU_STATUS_TRIPPED;
+	} else if (cur_temp >= data->ts.start_warning) {
+		return TMU_STATUS_WARNING;
+	} else if (cur_temp < data->ts.start_warning &&
+			cur_temp >= data->ts.min_val) {
+		return TMU_STATUS_NORMAL;
+	} else {
+		/* Temperature code does not lie between min 25 and max 125 */
+		gbl_info.tmu_state = TMU_STATUS_INIT;
+		debug("EXYNOS_TMU: Thermal reading failed\n");
+		return TMU_STATUS_INIT;
+	}
+}
+
+/*
+ * Get TMU specific pre-defined values from FDT
+ *
+ * @param info	pointer to the tmu_info struct
+ * @param blob  FDT blob
+ * @return	int value, 0 for success
+ */
+static int get_tmu_fdt_values(struct tmu_info *info, const void *blob)
+{
+#ifdef CONFIG_OF_CONTROL
+	int node;
+	int error = 0;
+
+	/* Get the node from FDT for TMU */
+	node = fdtdec_next_compatible(blob, 0,
+				      COMPAT_SAMSUNG_EXYNOS_TMU);
+	if (node < 0) {
+		debug("EXYNOS_TMU: No node for tmu in device tree\n");
+		return -1;
+	}
+
+	/*
+	 * Get the pre-defined TMU specific values from FDT.
+	 * All of these are expected to be correct otherwise
+	 * miscalculation of register values in tmu_setup_parameters
+	 * may result in misleading current temperature.
+	 */
+	info->tmu_base = fdtdec_get_addr(blob, node, "reg");
+	if (info->tmu_base == FDT_ADDR_T_NONE) {
+		debug("%s: Missing tmu-base\n", __func__);
+		return -1;
+	}
+	info->data.ts.min_val = fdtdec_get_int(blob,
+				node, "samsung,min-temp", -1);
+	error |= info->data.ts.min_val;
+	info->data.ts.max_val = fdtdec_get_int(blob,
+				node, "samsung,max-temp", -1);
+	error |= info->data.ts.max_val;
+	info->data.ts.start_warning = fdtdec_get_int(blob,
+				node, "samsung,start-warning", -1);
+	error |= info->data.ts.start_warning;
+	info->data.ts.start_tripping = fdtdec_get_int(blob,
+				node, "samsung,start-tripping", -1);
+	error |= info->data.ts.start_tripping;
+	info->data.efuse_min_value = fdtdec_get_int(blob,
+				node, "samsung,efuse-min-value", -1);
+	error |= info->data.efuse_min_value;
+	info->data.efuse_value = fdtdec_get_int(blob,
+				node, "samsung,efuse-value", -1);
+	error |= info->data.efuse_value;
+	info->data.efuse_max_value = fdtdec_get_int(blob,
+				node, "samsung,efuse-max-value", -1);
+	error |= info->data.efuse_max_value;
+	info->data.slope = fdtdec_get_int(blob,
+				node, "samsung,slope", -1);
+	error |= info->data.slope;
+	info->dc_value = fdtdec_get_int(blob,
+				node, "samsung,dc-value", -1);
+	error |= info->dc_value;
+
+	if (error == -1) {
+		debug("fail to get tmu node properties\n");
+		return -1;
+	}
+#endif
+
+	return 0;
+}
+
+/*
+ * Calibrate and calculate threshold values and
+ * enable interrupt levels
+ *
+ * @param	info pointer to the tmu_info struct
+ */
+static void tmu_setup_parameters(struct tmu_info *info)
+{
+	unsigned int te_code, con;
+	unsigned int warning_code, trip_code;
+	unsigned int cooling_temp;
+	unsigned int rising_value;
+	struct tmu_data *data = &info->data;
+	struct exynos5_tmu_reg *reg = (struct exynos5_tmu_reg *)info->tmu_base;
+
+	/* Must reload for reading efuse value from triminfo register */
+	writel(TRIMINFO_RELOAD, &reg->triminfo_control);
+
+	/* Get the compensation parameter */
+	te_code = readl(&reg->triminfo);
+	info->te1 = te_code & TRIM_INFO_MASK;
+	info->te2 = ((te_code >> 8) & TRIM_INFO_MASK);
+
+	if ((data->efuse_min_value > info->te1) ||
+			(info->te1 > data->efuse_max_value)
+			||  (info->te2 != 0))
+		info->te1 = data->efuse_value;
+
+	/* Get RISING & FALLING Threshold value */
+	warning_code = data->ts.start_warning
+			+ info->te1 - info->dc_value;
+	trip_code = data->ts.start_tripping
+			+ info->te1 - info->dc_value;
+	cooling_temp = 0;
+
+	rising_value = ((warning_code << 8) | (trip_code << 16));
+
+	/* Set interrupt level */
+	writel(rising_value, &reg->threshold_temp_rise);
+	writel(cooling_temp, &reg->threshold_temp_fall);
+
+	/*
+	 * Init TMU control tuning parameters
+	 * [28:24] VREF - Voltage reference
+	 * [15:13] THERM_TRIP_MODE - Tripping mode
+	 * [12] THERM_TRIP_EN - Thermal tripping enable
+	 * [11:8] BUF_SLOPE_SEL - Gain of amplifier
+	 * [6] THERM_TRIP_BY_TQ_EN - Tripping by TQ pin
+	 */
+	writel(data->slope, &reg->tmu_control);
+
+	writel(INTCLEARALL, &reg->intclear);
+
+	/* TMU core enable */
+	con = readl(&reg->tmu_control);
+	con |= CORE_EN;
+
+	writel(con, &reg->tmu_control);
+
+	/* LEV0 LEV1 LEV2 interrupt enable */
+	writel(INTEN_RISE0 | INTEN_RISE1 | INTEN_RISE2,	&reg->inten);
+}
+
+/*
+ * Initialize TMU device
+ *
+ * @param blob  FDT blob
+ * @return	int value, 0 for success
+ */
+int tmu_init(const void *blob)
+{
+	gbl_info.tmu_state = TMU_STATUS_INIT;
+	if (get_tmu_fdt_values(&gbl_info, blob) < 0)
+		goto ret;
+
+	tmu_setup_parameters(&gbl_info);
+	gbl_info.tmu_state = TMU_STATUS_NORMAL;
+ret:
+
+	return gbl_info.tmu_state;
+}