Subject: [PATCH 2/3] hwmon: Driver for OMAP3 temperature sensor

From: [email-masked] (Pavel Machek)
Date: Sat, 3 Jan 2015 10:18:58 +0100

On Mon 2014-12-29 11:04:48, Guenter Roeck wrote:
> On Mon, Dec 29, 2014 at 07:15:56PM +0100, Pavel Machek wrote:
> > On Mon 2014-12-29 12:01:03, Nishanth Menon wrote:
> > > On Mon, Dec 29, 2014 at 11:52 AM, Grazvydas Ignotas <[email-masked]> wrote:
> > > > On Fri, Dec 26, 2014 at 2:34 PM, Sebastian Reichel <[email-masked]> wrote:
> > > >> OMAP34xx and OMAP36xx processors contain a register in the syscon area,
> > > >> which can be used to determine the SoCs temperature. This patch provides
> > > >> a DT based driver for the temperature sensor based on an older driver
> > > >> written by Peter De Schrijver for the Nokia N900 and N9.
> > > >
> > > > The sensor looks like an earlier iteration of sensors used in newer
> > > > OMAPs, which are already supported by maybe
> > > > drivers/thermal/ti-soc-thermal/ , maybe it would make sense to update
> > > > that driver instead?
> > > 
> > > Just to be clear - OMAP4 is the first time that the sensors were
> > > reliable enough to be used.
> > 
> > When testing initial version of the patch, they seem to work very well
> > in the omap3 case.
> > 
> Pavel,
> 
> can you look into the omap4 thermal driver to see if it can be used ?

After some fixes... yes, it seems to be same hardware.

Signed-off-by: Pavel Machek <[email-masked]>

diff --git a/drivers/thermal/ti-soc-thermal/Kconfig b/drivers/thermal/ti-soc-thermal/Kconfig
index bd4c7be..a49495f 100644
--- a/drivers/thermal/ti-soc-thermal/Kconfig
+++ b/drivers/thermal/ti-soc-thermal/Kconfig
@@ -21,6 +21,15 @@ config TI_THERMAL
 	  This includes trip points definitions, extrapolation rules and
 	  CPU cooling device bindings.
 
+config OMAP3_THERMAL
+	bool "Texas Instruments OMAP3 thermal support"
+	depends on TI_SOC_THERMAL
+	depends on ARCH_OMAP3
+	help
+	  If you say yes here you get thermal support for the Texas Instruments
+	  OMAP3 SoC family. The current chip supported are:
+	   - OMAP3430
+
 config OMAP4_THERMAL
 	bool "Texas Instruments OMAP4 thermal support"
 	depends on TI_SOC_THERMAL
diff --git a/drivers/thermal/ti-soc-thermal/Makefile b/drivers/thermal/ti-soc-thermal/Makefile
index 1226b24..2b5b220 100644
--- a/drivers/thermal/ti-soc-thermal/Makefile
+++ b/drivers/thermal/ti-soc-thermal/Makefile
@@ -2,5 +2,6 @@ obj-$(CONFIG_TI_SOC_THERMAL)		+= ti-soc-thermal.o
 ti-soc-thermal-y			:= ti-bandgap.o
 ti-soc-thermal-$(CONFIG_TI_THERMAL)	+= ti-thermal-common.o
 ti-soc-thermal-$(CONFIG_DRA752_THERMAL)	+= dra752-thermal-data.o
+ti-soc-thermal-$(CONFIG_OMAP3_THERMAL)  += omap3-thermal-data.o
 ti-soc-thermal-$(CONFIG_OMAP4_THERMAL)	+= omap4-thermal-data.o
 ti-soc-thermal-$(CONFIG_OMAP5_THERMAL)	+= omap5-thermal-data.o
diff --git a/drivers/thermal/ti-soc-thermal/omap3-thermal-data.c b/drivers/thermal/ti-soc-thermal/omap3-thermal-data.c
new file mode 100644
index 0000000..a79ebf2
--- /dev/null
+++ b/drivers/thermal/ti-soc-thermal/omap3-thermal-data.c
@@ -0,0 +1,99 @@
+/*
+ * OMAP3 thermal driver.
+ *
+ * Copyright (C) 2011-2012 Texas Instruments Inc.
+ * Copyright (C) 2014 Pavel Machek <[email-masked]>
+ *
+ * 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 "ti-thermal.h"
+#include "ti-bandgap.h"
+
+/*
+ * OMAP34XX has one instance of thermal sensor for MPU
+ * need to describe the individual bit fields
+ */
+static struct temp_sensor_registers
+omap34xx_mpu_temp_sensor_registers = {
+	.temp_sensor_ctrl = 0,
+	.bgap_tempsoff_mask = 0, /* Unused, we don't have POWER_SWITCH */
+	.bgap_soc_mask = BIT(8),
+	.bgap_eocz_mask = BIT(7),
+	.bgap_dtemp_mask = 0x7f,
+
+	.bgap_mode_ctrl = 0,
+	.mode_ctrl_mask = 0,	/* Unused, no MODE_CONFIG */
+
+	.bgap_efuse = 0,
+};
+
+/* Thresholds and limits for OMAP34XX MPU temperature sensor */
+static struct temp_sensor_data omap34xx_mpu_temp_sensor_data = {
+	.min_freq = 32768,
+	.max_freq = 32768,
+	.max_temp = -99000,
+	.min_temp = 99000,
+	.hyst_val = 5000,
+};
+
+/*
+ * Temperature values in milli degree celsius
+ * ADC code values from 530 to 923
+ */
+static const int
+omap34xx_adc_to_temp[] = {
+	-40000, -40000, -40000, -40000, -40000, -39000, -38000, -36000,
+	-34000, -32000, -31000,	-29000, -28000, -26000, -25000, -24000,
+	-22000, -21000, -19000, -18000, -17000, -15000,	-14000, -12000,
+	-11000, -9000, -8000, -7000, -5000, -4000, -2000, -1000, 0000,
+	1000, 3000, 4000, 5000, 7000, 8000, 10000, 11000, 13000, 14000,
+	15000, 17000, 18000, 20000, 21000, 22000, 24000, 25000, 27000,
+	28000, 30000, 31000, 32000, 34000, 35000, 37000, 38000, 39000,
+	41000, 42000, 44000, 45000, 47000, 48000, 49000, 51000, 52000,
+	53000, 55000, 56000, 58000, 59000, 60000, 62000, 63000, 65000,
+	66000, 67000, 69000, 70000, 72000, 73000, 74000, 76000, 77000,
+	79000, 80000, 81000, 83000, 84000, 85000, 87000, 88000, 89000,
+	91000, 92000, 94000, 95000, 96000, 98000, 99000, 100000,
+	102000, 103000, 105000, 106000, 107000, 109000, 110000, 111000,
+	113000, 114000, 116000, 117000, 118000, 120000, 121000, 122000,
+	124000, 124000, 125000, 125000, 125000, 125000,	125000
+};
+
+/* OMAP34XX data */
+const struct ti_bandgap_data omap34xx_data = {
+	.features = TI_BANDGAP_FEATURE_CLK_CTRL,
+	.fclock_name = "ts_fck",
+	.div_ck_name = "ts_fck",
+	.conv_table = omap34xx_adc_to_temp,
+	.adc_start_val = 0,
+	.adc_end_val = 127,
+	.expose_sensor = ti_thermal_expose_sensor,
+	.remove_sensor = ti_thermal_remove_sensor,
+
+	.sensors = {
+		{
+		.registers = &omap34xx_mpu_temp_sensor_registers,
+		.ts_data = &omap34xx_mpu_temp_sensor_data,
+		.domain = "cpu",
+		.slope = 0,
+		.constant = 20000,
+		.slope_pcb = 0,
+		.constant_pcb = 20000,
+		.register_cooling = NULL,
+		.unregister_cooling = NULL,
+		},
+	},
+	.sensor_count = 1,
+
+//	.sensor_count = 0,
+};
+
diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
index 634b6ce..a4180a5 100644
--- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c
+++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
@@ -40,6 +40,7 @@
 #include <linux/of_irq.h>
 #include <linux/of_gpio.h>
 #include <linux/io.h>
+#include <linux/delay.h>
 
 #include "ti-bandgap.h"
 
@@ -103,19 +104,15 @@ do {								\
  */
 static int ti_bandgap_power(struct ti_bandgap *bgp, bool on)
 {
-	int i, ret = 0;
+	int i;
 
-	if (!TI_BANDGAP_HAS(bgp, POWER_SWITCH)) {
-		ret = -ENOTSUPP;
-		goto exit;
-	}
+	if (!TI_BANDGAP_HAS(bgp, POWER_SWITCH))
+		return -ENOTSUPP;
 
 	for (i = 0; i < bgp->conf->sensor_count; i++)
 		/* active on 0 */
 		RMW_BITS(bgp, i, temp_sensor_ctrl, bgap_tempsoff_mask, !on);
-
-exit:
-	return ret;
+	return 0;
 }
 
 /**
@@ -154,6 +151,7 @@ static u32 ti_bandgap_read_temp(struct ti_bandgap *bgp, int id)
 	if (TI_BANDGAP_HAS(bgp, FREEZE_BIT))
 		RMW_BITS(bgp, id, bgap_mask_ctrl, mask_freeze_mask, 0);
 
+	printk("Bandgap: ADC is %d\n", temp);
 	return temp;
 }
 
@@ -263,18 +261,13 @@ static
 int ti_bandgap_adc_to_mcelsius(struct ti_bandgap *bgp, int adc_val, int *t)
 {
 	const struct ti_bandgap_data *conf = bgp->conf;
-	int ret = 0;
 
 	/* look up for temperature in the table and return the temperature */
-	if (adc_val < conf->adc_start_val || adc_val > conf->adc_end_val) {
-		ret = -ERANGE;
-		goto exit;
-	}
+	if (adc_val < conf->adc_start_val || adc_val > conf->adc_end_val)
+		return -ERANGE;
 
 	*t = bgp->conf->conv_table[adc_val - conf->adc_start_val];
-
-exit:
-	return ret;
+	return 0;
 }
 
 /**
@@ -295,16 +288,14 @@ int ti_bandgap_mcelsius_to_adc(struct ti_bandgap *bgp, long temp, int *adc)
 {
 	const struct ti_bandgap_data *conf = bgp->conf;
 	const int *conv_table = bgp->conf->conv_table;
-	int high, low, mid, ret = 0;
+	int high, low, mid;
 
 	low = 0;
 	high = conf->adc_end_val - conf->adc_start_val;
 	mid = (high + low) / 2;
 
-	if (temp < conv_table[low] || temp > conv_table[high]) {
-		ret = -ERANGE;
-		goto exit;
-	}
+	if (temp < conv_table[low] || temp > conv_table[high])
+		return -ERANGE;
 
 	while (low < high) {
 		if (temp < conv_table[mid])
@@ -315,9 +306,7 @@ int ti_bandgap_mcelsius_to_adc(struct ti_bandgap *bgp, long temp, int *adc)
 	}
 
 	*adc = conf->adc_start_val + low;
-
-exit:
-	return ret;
+	return 0;
 }
 
 /**
@@ -343,13 +332,11 @@ int ti_bandgap_add_hyst(struct ti_bandgap *bgp, int adc_val, int hyst_val,
 	 */
 	ret = ti_bandgap_adc_to_mcelsius(bgp, adc_val, &temp);
 	if (ret < 0)
-		goto exit;
+		return ret;
 
 	temp += hyst_val;
 
 	ret = ti_bandgap_mcelsius_to_adc(bgp, temp, sum);
-
-exit:
 	return ret;
 }
 
@@ -468,22 +455,18 @@ exit:
  */
 static inline int ti_bandgap_validate(struct ti_bandgap *bgp, int id)
 {
-	int ret = 0;
-
 	if (!bgp || IS_ERR(bgp)) {
 		pr_err("%s: invalid bandgap pointer\n", __func__);
-		ret = -EINVAL;
-		goto exit;
+		return -EINVAL;
 	}
 
 	if ((id < 0) || (id >= bgp->conf->sensor_count)) {
 		dev_err(bgp->dev, "%s: sensor id out of range (%d)\n",
 			__func__, id);
-		ret = -ERANGE;
+		return -ERANGE;
 	}
 
-exit:
-	return ret;
+	return 0;
 }
 
 /**
@@ -511,12 +494,10 @@ static int _ti_bandgap_write_threshold(struct ti_bandgap *bgp, int id, int val,
 
 	ret = ti_bandgap_validate(bgp, id);
 	if (ret)
-		goto exit;
+		return ret;
 
-	if (!TI_BANDGAP_HAS(bgp, TALERT)) {
-		ret = -ENOTSUPP;
-		goto exit;
-	}
+	if (!TI_BANDGAP_HAS(bgp, TALERT))
+		return -ENOTSUPP;
 
 	ts_data = bgp->conf->sensors[id].ts_data;
 	tsr = bgp->conf->sensors[id].registers;
@@ -529,17 +510,15 @@ static int _ti_bandgap_write_threshold(struct ti_bandgap *bgp, int id, int val,
 	}
 
 	if (ret)
-		goto exit;
-
+		return ret;
+	
 	ret = ti_bandgap_mcelsius_to_adc(bgp, val, &adc_val);
 	if (ret < 0)
-		goto exit;
+		return ret;		
 
 	spin_lock(&bgp->lock);
 	ret = ti_bandgap_update_alert_threshold(bgp, id, adc_val, hot);
 	spin_unlock(&bgp->lock);
-
-exit:
 	return ret;
 }
 
@@ -582,7 +561,7 @@ static int _ti_bandgap_read_threshold(struct ti_bandgap *bgp, int id,
 
 	temp = ti_bandgap_readl(bgp, tsr->bgap_threshold);
 	temp = (temp & mask) >> __ffs(mask);
-	ret |= ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
+	ret = ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
 	if (ret) {
 		dev_err(bgp->dev, "failed to read thot\n");
 		ret = -EIO;
@@ -856,10 +835,11 @@ int ti_bandgap_read_temperature(struct ti_bandgap *bgp, int id,
 	temp = ti_bandgap_read_temp(bgp, id);
 	spin_unlock(&bgp->lock);
 
-	ret |= ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
+	ret = ti_bandgap_adc_to_mcelsius(bgp, temp, &temp);
 	if (ret)
 		return -EIO;
 
+	printk("Bandgap: temperature is %d\n", temp);
 	*temperature = temp;
 
 	return 0;
@@ -918,6 +898,7 @@ static int
 ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
 {
 	u32 temp = 0, counter = 1000;
+	struct temp_sensor_registers *tsr;
 
 	/* Select single conversion mode */
 	if (TI_BANDGAP_HAS(bgp, MODE_CONFIG))
@@ -925,16 +906,26 @@ ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
 
 	/* Start of Conversion = 1 */
 	RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 1);
-	/* Wait until DTEMP is updated */
-	temp = ti_bandgap_read_temp(bgp, id);
 
-	while ((temp == 0) && --counter)
-		temp = ti_bandgap_read_temp(bgp, id);
-	/* REVISIT: Check correct condition for end of conversion */
+	/* Wait for EOCZ going up */
+	tsr = bgp->conf->sensors[id].registers;
+	
+	while (--counter) {
+		if (ti_bandgap_readl(bgp, tsr->temp_sensor_ctrl) & tsr->bgap_eocz_mask)
+			break;
+		printk("@");
+	}
 
 	/* Start of Conversion = 0 */
 	RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 0);
 
+	counter = 1000;
+	while (--counter) {
+		if (!(ti_bandgap_readl(bgp, tsr->temp_sensor_ctrl) & tsr->bgap_eocz_mask))
+			break;
+		printk("#");
+	}
+
 	return 0;
 }
 
@@ -1196,6 +1187,8 @@ int ti_bandgap_probe(struct platform_device *pdev)
 	struct ti_bandgap *bgp;
 	int clk_rate, ret = 0, i;
 
+	printk("ti_bandgap: probe\n");
+
 	bgp = ti_bandgap_build(pdev);
 	if (IS_ERR(bgp)) {
 		dev_err(&pdev->dev, "failed to fetch platform data\n");
@@ -1220,11 +1213,10 @@ int ti_bandgap_probe(struct platform_device *pdev)
 		goto free_irqs;
 	}
 
-	bgp->div_clk = clk_get(NULL,  bgp->conf->div_ck_name);
+	bgp->div_clk = clk_get(NULL, bgp->conf->div_ck_name);
 	ret = IS_ERR(bgp->div_clk);
 	if (ret) {
-		dev_err(&pdev->dev,
-			"failed to request div_ts_ck clock ref\n");
+		dev_err(&pdev->dev, "failed to request div_ts_ck clock ref\n");
 		ret = PTR_ERR(bgp->div_clk);
 		goto free_irqs;
 	}
@@ -1312,6 +1304,8 @@ int ti_bandgap_probe(struct platform_device *pdev)
 	/* Every thing is good? Then expose the sensors */
 	for (i = 0; i < bgp->conf->sensor_count; i++) {
 		char *domain;
+		extern int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
+					     char *domain);
 
 		if (bgp->conf->sensors[i].register_cooling) {
 			ret = bgp->conf->sensors[i].register_cooling(bgp, i);
@@ -1319,12 +1313,29 @@ int ti_bandgap_probe(struct platform_device *pdev)
 				goto remove_sensors;
 		}
 
+		printk("bandgap: exposing sensor: %p\n", bgp->conf->expose_sensor);
+		
 		if (bgp->conf->expose_sensor) {
+			printk("bandgap: calling %p %p\n", bgp->conf->expose_sensor, ti_thermal_expose_sensor);
 			domain = bgp->conf->sensors[i].domain;
 			ret = bgp->conf->expose_sensor(bgp, i, domain);
+			printk("bandgap: done\n");
 			if (ret)
 				goto remove_last_cooling;
 		}
+
+		printk("bandgap: exposing sensor\n");
+		{
+			int t;
+
+			ti_bandgap_force_single_read(bgp, 0);
+
+			t = ti_bandgap_read_temp(bgp, 0);
+			printk("Temperature ADC: %d\n", t);			
+			ti_bandgap_read_temperature(bgp, 0, &t);
+			printk("Temperature: %d\n", t);
+			mdelay(1000);
+		}
 	}
 
 	/*
@@ -1365,6 +1376,8 @@ free_irqs:
 		free_irq(gpio_to_irq(bgp->tshut_gpio), NULL);
 		gpio_free(bgp->tshut_gpio);
 	}
+	printk("ti_bandgap: probe: something failed\n");
+	mdelay(10000);
 
 	return ret;
 }
@@ -1509,6 +1522,12 @@ static SIMPLE_DEV_PM_OPS(ti_bandgap_dev_pm_ops, ti_bandgap_suspend,
 #endif
 
 static const struct of_device_id of_ti_bandgap_match[] = {
+#ifdef CONFIG_OMAP3_THERMAL
+	{
+		.compatible = "ti,omap34xx-bandgap",
+		.data = (void *)&omap34xx_data,
+	},
+#endif
 #ifdef CONFIG_OMAP4_THERMAL
 	{
 		.compatible = "ti,omap4430-bandgap",
diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.h b/drivers/thermal/ti-soc-thermal/ti-bandgap.h
index b3adf72..3f05386 100644
--- a/drivers/thermal/ti-soc-thermal/ti-bandgap.h
+++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.h
@@ -384,6 +384,8 @@ int ti_bandgap_set_sensor_data(struct ti_bandgap *bgp, int id, void *data);
 void *ti_bandgap_get_sensor_data(struct ti_bandgap *bgp, int id);
 int ti_bandgap_get_trend(struct ti_bandgap *bgp, int id, int *trend);
 
+extern const struct ti_bandgap_data omap34xx_data;
+
 #ifdef CONFIG_OMAP4_THERMAL
 extern const struct ti_bandgap_data omap4430_data;
 extern const struct ti_bandgap_data omap4460_data;
diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
index 5fd0386..f91655f 100644
--- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
+++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
@@ -328,18 +328,23 @@ int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
 {
 	struct ti_thermal_data *data;
 
+	printk("expose_sensor\n");
+
 	data = ti_bandgap_get_sensor_data(bgp, id);
 
 	if (!data || IS_ERR(data))
 		data = ti_thermal_build_data(bgp, id);
 
-	if (!data)
+	if (!data) {
+		printk("no data\n");	
 		return -EINVAL;
+	}
 
 	/* in case this is specified by DT */
 	data->ti_thermal = thermal_zone_of_sensor_register(bgp->dev, id,
 					data, &ti_of_thermal_ops);
 	if (IS_ERR(data->ti_thermal)) {
+		printk("of_sensor_register failed\n");
 		/* Create thermal zone */
 		data->ti_thermal = thermal_zone_device_register(domain,
 				OMAP_TRIP_NUMBER, 0, data, &ti_thermal_ops,

-- 
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