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* [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU
@ 2011-08-25  8:13 Donggeun Kim
  2011-08-25  9:17 ` Jean Delvare
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: Donggeun Kim @ 2011-08-25  8:13 UTC (permalink / raw)
  To: lm-sensors

This patch allows to read temperature
from TMU(Thermal Management Unit) of SAMSUNG EXYNOS4 series of SoC.

Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 Documentation/hwmon/exynos4_tmu           |   66 ++++
 drivers/hwmon/Kconfig                     |   10 +
 drivers/hwmon/Makefile                    |    1 +
 drivers/hwmon/exynos4_tmu.c               |  478 +++++++++++++++++++++++++++++
 include/linux/platform_data/exynos4_tmu.h |   83 +++++
 5 files changed, 638 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/hwmon/exynos4_tmu
 create mode 100644 drivers/hwmon/exynos4_tmu.c
 create mode 100644 include/linux/platform_data/exynos4_tmu.h

diff --git a/Documentation/hwmon/exynos4_tmu b/Documentation/hwmon/exynos4_tmu
new file mode 100644
index 0000000..27d8ab6
--- /dev/null
+++ b/Documentation/hwmon/exynos4_tmu
@@ -0,0 +1,66 @@
+Kernel driver exynos4_tmu
+========+
+Supported chips:
+* ARM SAMSUNG EXYNOS4 series of SoC
+  Prefix: 'exynos4-tmu'
+  Datasheet: Not publicly available
+
+Authors: Donggeun Kim <dg77.kim@samsung.com>
+
+Description
+-----------
+
+This driver allows to read temperature inside SAMSUNG EXYNOS4 series of SoC.
+
+The chip only exposes the measured 8-bit temperature code value
+through a register.
+Temperature can be taken from the temperature code.
+There are three equations converting from temperature to temperature code.
+
+The three equations are:
+  1. Two point trimming
+ 	Tc = (T - 25) * (TI2 - TI1) / (85 - 25) + TI1
+
+  2. One point trimming
+ 	Tc = T + TI1 - 25
+
+  3. No trimming
+ 	Tc = T + 50
+
+  Tc: Temperature code, T: Temperature,
+  TI1: Trimming info for 25 degree Celsius (stored at TRIMINFO register)
+       Temperature code measured at 25 degree Celsius which is unchanged
+  TI2: Trimming info for 85 degree Celsius (stored at TRIMINFO register)
+       Temperature code measured at 85 degree Celsius which is unchanged
+
+TMU(Thermal Management Unit) in EXYNOS4 generates interrupt
+when temperature exceeds pre-defined levels.
+The maximum number of configurable threshold is four.
+The threshold levels are defined as follows:
+  Level_0: current temperature > trigger_level_0 + threshold
+  Level_1: current temperature > trigger_level_1 + threshold
+  Level_2: current temperature > trigger_level_2 + threshold
+  Level_3: current temperature > trigger_level_3 + threshold
+
+  The threshold and each trigger_level are set
+  through the corresponding registers.
+
+When an interrupt occurs, this driver notify user space of
+one of four threshold levels for the interrupt
+through kobject_uevent_env and sysfs_notify functions.
+
+Sysfs Interface
+---------------
+name		name of the temperature sensor
+		RO
+
+temp1_input	temperature
+		RO
+
+temp1_alarm	shows which interrupt threshold level is met
+		1: current temperature exceeds level_0
+		10: current temperature exceeds level_1
+		100: current temperature exceeds level_2
+		1000: current temperature exceeds level_3
+		RO
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 0b62c3c..c6fb761 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -303,6 +303,16 @@ config SENSORS_DS1621
 	  This driver can also be built as a module.  If so, the module
 	  will be called ds1621.
 
+config SENSORS_EXYNOS4_TMU
+	tristate "Temperature sensor on Samsung EXYNOS4"
+	depends on EXYNOS4_DEV_TMU
+	help
+	  If you say yes here you get support for TMU (Thermal Managment
+	  Unit) on SAMSUNG EXYNOS4 series of SoC.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called exynos4-tmu.
+
 config SENSORS_I5K_AMB
 	tristate "FB-DIMM AMB temperature sensor on Intel 5000 series chipsets"
 	depends on PCI && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 3c9ccef..dbd8963 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o
 obj-$(CONFIG_SENSORS_EMC1403)	+= emc1403.o
 obj-$(CONFIG_SENSORS_EMC2103)	+= emc2103.o
 obj-$(CONFIG_SENSORS_EMC6W201)	+= emc6w201.o
+obj-$(CONFIG_SENSORS_EXYNOS4_TMU)	+= exynos4_tmu.o
 obj-$(CONFIG_SENSORS_F71805F)	+= f71805f.o
 obj-$(CONFIG_SENSORS_F71882FG)	+= f71882fg.o
 obj-$(CONFIG_SENSORS_F75375S)	+= f75375s.o
diff --git a/drivers/hwmon/exynos4_tmu.c b/drivers/hwmon/exynos4_tmu.c
new file mode 100644
index 0000000..b433c47
--- /dev/null
+++ b/drivers/hwmon/exynos4_tmu.c
@@ -0,0 +1,478 @@
+/*
+ * exynos4_tmu.c - Samsung EXYNOS4 TMU (Thermal Management Unit)
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *  Donggeun Kim <dg77.kim@samsung.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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * 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 <linux/module.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/workqueue.h>
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/io.h>
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+
+#include <linux/platform_data/exynos4_tmu.h>
+
+#define EXYNOS4_TMU_REG_TRIMINFO	0x0
+#define EXYNOS4_TMU_REG_CONTROL		0x20
+#define EXYNOS4_TMU_REG_STATUS		0x28
+#define EXYNOS4_TMU_REG_CURRENT_TEMP	0x40
+#define EXYNOS4_TMU_REG_THRESHOLD_TEMP	0x44
+#define EXYNOS4_TMU_REG_TRIG_LEVEL0	0x50
+#define EXYNOS4_TMU_REG_TRIG_LEVEL1	0x54
+#define EXYNOS4_TMU_REG_TRIG_LEVEL2	0x58
+#define EXYNOS4_TMU_REG_TRIG_LEVEL3	0x5C
+#define EXYNOS4_TMU_REG_PAST_TEMP0	0x60
+#define EXYNOS4_TMU_REG_PAST_TEMP1	0x64
+#define EXYNOS4_TMU_REG_PAST_TEMP2	0x68
+#define EXYNOS4_TMU_REG_PAST_TEMP3	0x6C
+#define EXYNOS4_TMU_REG_INTEN		0x70
+#define EXYNOS4_TMU_REG_INTSTAT		0x74
+#define EXYNOS4_TMU_REG_INTCLEAR	0x78
+
+#define EXYNOS4_TMU_GAIN_SHIFT		8
+#define EXYNOS4_TMU_REF_VOLTAGE_SHIFT	24
+
+#define EXYNOS4_TMU_TRIM_TEMP_MASK	0xff
+#define EXYNOS4_TMU_CORE_ON	3
+#define EXYNOS4_TMU_CORE_OFF	2
+#define EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET	50
+#define EXYNOS4_TMU_TRIG_LEVEL0_MASK	0x1
+#define EXYNOS4_TMU_TRIG_LEVEL1_MASK	0x10
+#define EXYNOS4_TMU_TRIG_LEVEL2_MASK	0x100
+#define EXYNOS4_TMU_TRIG_LEVEL3_MASK	0x1000
+#define EXYNOS4_TMU_INTCLEAR_VAL	0x1111
+
+struct exynos4_tmu_data {
+	struct exynos4_tmu_platform_data *pdata;
+	struct device *hwmon_dev;
+	struct resource *mem;
+	void __iomem *base;
+	int irq;
+	struct work_struct irq_work;
+	struct clk *clk;
+	unsigned int interrupt_stat;
+	u8 temp_error1, temp_error2;
+};
+
+/*
+ * TMU treats temperature as a mapped temperature code.
+ * The temperature is converted differently depending on the calibration type.
+ */
+static u8 translate_temp_to_code(struct exynos4_tmu_data *data, u8 temp)
+{
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	unsigned int temp_code;
+
+	switch (pdata->cal_type) {
+	case TYPE_TWO_POINT_TRIMMING:
+		temp_code = (temp - 25) *
+		    (data->temp_error2 - data->temp_error1) /
+		    (85 - 25) + data->temp_error1;
+		break;
+	case TYPE_ONE_POINT_TRIMMING:
+		temp_code = temp + data->temp_error1 - 25;
+		break;
+	default:
+		temp_code = temp + EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET;
+		break;
+	}
+
+	return temp_code;
+}
+
+/*
+ * Calculate a temperature value from a temperature code.
+ * The unit of the temperature is degree Celsius.
+ */
+static u8 translate_code_to_temp(struct exynos4_tmu_data *data, u8 temp_code)
+{
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	unsigned int temp;
+
+	switch (pdata->cal_type) {
+	case TYPE_TWO_POINT_TRIMMING:
+		temp = (temp_code - data->temp_error1) * (85 - 25) /
+		    (data->temp_error2 - data->temp_error1) + 25;
+		break;
+	case TYPE_ONE_POINT_TRIMMING:
+		temp = temp_code - data->temp_error1 + 25;
+		break;
+	default:
+		temp = temp_code - EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET;
+		break;
+	}
+
+	return temp;
+}
+
+static void exynos4_tmu_initialize(struct platform_device *pdev)
+{
+	struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	unsigned int status, trim_info, interrupt_en;
+	u8 threshold_code;
+
+	clk_enable(data->clk);
+
+	status = readb(data->base + EXYNOS4_TMU_REG_STATUS);
+	if (!status) {
+		printk(KERN_INFO "TMU is busy\n");
+		clk_disable(data->clk);
+		return;
+	}
+
+	/* Save trimming info in order to perform calibration */
+	trim_info = readl(data->base + EXYNOS4_TMU_REG_TRIMINFO);
+	data->temp_error1 = trim_info & EXYNOS4_TMU_TRIM_TEMP_MASK;
+	data->temp_error2 = ((trim_info >> 8) & EXYNOS4_TMU_TRIM_TEMP_MASK);
+
+	/* Write temperature code for threshold */
+	threshold_code = translate_temp_to_code(data, pdata->threshold);
+	writeb(threshold_code,
+		data->base + EXYNOS4_TMU_REG_THRESHOLD_TEMP);
+
+	writeb(pdata->trigger_level0,
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL0);
+	writeb(pdata->trigger_level1,
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL1);
+	writeb(pdata->trigger_level2,
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL2);
+	writeb(pdata->trigger_level3,
+		data->base + EXYNOS4_TMU_REG_TRIG_LEVEL3);
+
+	writel(EXYNOS4_TMU_INTCLEAR_VAL,
+		data->base + EXYNOS4_TMU_REG_INTCLEAR);
+
+	interrupt_en = pdata->trigger_level3_en << 12 |
+		pdata->trigger_level2_en << 8 |
+		pdata->trigger_level1_en << 4 |
+		pdata->trigger_level0_en;
+	writel(interrupt_en, data->base + EXYNOS4_TMU_REG_INTEN);
+
+	clk_disable(data->clk);
+}
+
+static void exynos4_tmu_control(struct platform_device *pdev, bool on)
+{
+	struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
+	struct exynos4_tmu_platform_data *pdata = data->pdata;
+	unsigned int con;
+
+	clk_enable(data->clk);
+
+	con = pdata->reference_voltage << EXYNOS4_TMU_REF_VOLTAGE_SHIFT |
+		pdata->gain << EXYNOS4_TMU_GAIN_SHIFT;
+	if (on)
+		con |= EXYNOS4_TMU_CORE_ON;
+	else
+		con |= EXYNOS4_TMU_CORE_OFF;
+
+	writel(con, data->base + EXYNOS4_TMU_REG_CONTROL);
+
+	clk_disable(data->clk);
+}
+
+static int exynos4_tmu_read(struct exynos4_tmu_data *data, u8 *temp)
+{
+	u8 temp_code;
+
+	clk_enable(data->clk);
+
+	temp_code = readb(data->base + EXYNOS4_TMU_REG_CURRENT_TEMP);
+	if (!temp_code) {
+		dev_err(data->hwmon_dev, "Failed to read temperature code\n");
+		clk_disable(data->clk);
+		return -EAGAIN;
+	}
+	*temp = translate_code_to_temp(data, temp_code);
+
+	clk_disable(data->clk);
+
+	return 0;
+}
+
+static void exynos4_tmu_work(struct work_struct *work)
+{
+	struct exynos4_tmu_data *data = container_of(work,
+			struct exynos4_tmu_data, irq_work);
+	char *envp[2];
+
+	clk_enable(data->clk);
+
+	data->interrupt_stat = readl(data->base + EXYNOS4_TMU_REG_INTSTAT);
+
+	writel(EXYNOS4_TMU_INTCLEAR_VAL, data->base + EXYNOS4_TMU_REG_INTCLEAR);
+
+	if (data->interrupt_stat & EXYNOS4_TMU_TRIG_LEVEL3_MASK)
+		envp[0] = "TRIG_LEVEL=3";
+	else if (data->interrupt_stat & EXYNOS4_TMU_TRIG_LEVEL2_MASK)
+		envp[0] = "TRIG_LEVEL=2";
+	else if (data->interrupt_stat & EXYNOS4_TMU_TRIG_LEVEL1_MASK)
+		envp[0] = "TRIG_LEVEL=1";
+	else
+		envp[0] = "TRIG_LEVEL=0";
+	envp[1] = NULL;
+
+	sysfs_notify(&data->hwmon_dev->kobj, NULL, "temp1_alarm");
+	kobject_uevent_env(&data->hwmon_dev->kobj, KOBJ_CHANGE, envp);
+	enable_irq(data->irq);
+
+	clk_disable(data->clk);
+}
+
+static irqreturn_t exynos4_tmu_irq(int irq, void *id)
+{
+	struct exynos4_tmu_data *data = id;
+
+	if (!work_pending(&data->irq_work)) {
+		disable_irq_nosync(irq);
+		schedule_work(&data->irq_work);
+	} else {
+		dev_err(data->hwmon_dev, "irq_work pending\n");
+	}
+
+	return IRQ_HANDLED;
+}
+
+static ssize_t exynos4_tmu_show_name(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "exynos4-tmu\n");
+}
+
+static ssize_t exynos4_tmu_show_temp(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct exynos4_tmu_data *data = dev_get_drvdata(dev);
+	int ret;
+	u8 temp;
+
+	ret = exynos4_tmu_read(data, &temp);
+	if (ret)
+		return ret;
+	/* convert from degree Celsius to millidegree Celsius */
+	return sprintf(buf, "%d\n", temp * 1000);
+}
+
+static ssize_t exynos4_tmu_show_alarm(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct exynos4_tmu_data *data = dev_get_drvdata(dev);
+
+	/*
+	 * 1: trigger_level0 interrupt generated
+	 * 10: trigger_level1 interrupt generated
+	 * 100: trigger_level2 interrupt generated
+	 * 1000: trigger_level3 interrupt generated
+	 */
+	return sprintf(buf, "%x\n", data->interrupt_stat);
+}
+
+static DEVICE_ATTR(name, S_IRUGO, exynos4_tmu_show_name, NULL);
+static DEVICE_ATTR(temp1_alarm, S_IRUGO, exynos4_tmu_show_alarm, NULL);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, exynos4_tmu_show_temp, NULL, 0);
+
+static struct attribute *exynos4_tmu_attributes[] = {
+	&dev_attr_name.attr,
+	&dev_attr_temp1_alarm.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group exynos4_tmu_attr_group = {
+	.attrs = exynos4_tmu_attributes,
+};
+
+static int __devinit exynos4_tmu_probe(struct platform_device *pdev)
+{
+	struct exynos4_tmu_data *data;
+	struct exynos4_tmu_platform_data *pdata = pdev->dev.platform_data;
+	int ret;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform init data supplied.\n");
+		return -ENODEV;
+	}
+
+	data = kzalloc(sizeof(struct exynos4_tmu_data), GFP_KERNEL);
+	if (!data) {
+		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
+		return -ENOMEM;
+	}
+
+	data->irq = platform_get_irq(pdev, 0);
+	if (data->irq < 0) {
+		ret = data->irq;
+		dev_err(&pdev->dev, "Failed to get platform irq1\n");
+		goto err_free;
+	}
+
+	INIT_WORK(&data->irq_work, exynos4_tmu_work);
+
+	data->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!data->mem) {
+		ret = -ENOENT;
+		dev_err(&pdev->dev, "Failed to get platform resource\n");
+		goto err_free;
+	}
+
+	data->mem = request_mem_region(data->mem->start,
+			resource_size(data->mem), pdev->name);
+	if (!data->mem) {
+		ret = -EBUSY;
+		dev_err(&pdev->dev, "Failed to request memory region\n");
+		goto err_free;
+	}
+
+	data->base = ioremap(data->mem->start, resource_size(data->mem));
+	if (!data->base) {
+		ret = -EBUSY;
+		dev_err(&pdev->dev, "Failed to ioremap memory\n");
+		goto err_mem_region;
+	}
+
+	ret = request_irq(data->irq, exynos4_tmu_irq,
+		IRQF_DISABLED | IRQF_TRIGGER_RISING,
+		"exynos4-tmu", data);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
+		goto err_io_remap;
+	}
+
+	data->clk = clk_get(NULL, "tmu_apbif");
+	if (IS_ERR(data->clk)) {
+		ret = -EINVAL;
+		dev_err(&pdev->dev, "Failed to get clock\n");
+		goto err_irq;
+	}
+
+	data->pdata = pdata;
+	platform_set_drvdata(pdev, data);
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
+		goto err_clk;
+	}
+
+	data->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		ret = PTR_ERR(data->hwmon_dev);
+		goto err_create_group;
+	}
+
+	exynos4_tmu_initialize(pdev);
+	exynos4_tmu_control(pdev, true);
+
+	return 0;
+
+err_create_group:
+	sysfs_remove_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
+err_clk:
+	platform_set_drvdata(pdev, NULL);
+	clk_put(data->clk);
+err_irq:
+	free_irq(data->irq, data);
+err_io_remap:
+	iounmap(data->base);
+err_mem_region:
+	release_mem_region(data->mem->start, resource_size(data->mem));
+err_free:
+	kfree(data);
+
+	return ret;
+}
+
+static int __devexit exynos4_tmu_remove(struct platform_device *pdev)
+{
+	struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
+
+	clk_put(data->clk);
+
+	free_irq(data->irq, data);
+
+	iounmap(data->base);
+	release_mem_region(data->mem->start, resource_size(data->mem));
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfree(data);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int exynos4_tmu_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	exynos4_tmu_control(pdev, false);
+
+	return 0;
+}
+
+static int exynos4_tmu_resume(struct platform_device *pdev)
+{
+	exynos4_tmu_initialize(pdev);
+	exynos4_tmu_control(pdev, true);
+
+	return 0;
+}
+#else
+#define exynos4_tmu_suspend NULL
+#define exynos4_tmu_resume NULL
+#endif
+
+static struct platform_driver exynos4_tmu_driver = {
+	.driver = {
+		.name   = "exynos4-tmu",
+		.owner  = THIS_MODULE,
+	},
+	.probe = exynos4_tmu_probe,
+	.remove	= __devexit_p(exynos4_tmu_remove),
+	.suspend = exynos4_tmu_suspend,
+	.resume = exynos4_tmu_resume,
+};
+
+static int __init exynos4_tmu_driver_init(void)
+{
+	return platform_driver_register(&exynos4_tmu_driver);
+}
+module_init(exynos4_tmu_driver_init);
+
+static void __exit exynos4_tmu_driver_exit(void)
+{
+	platform_driver_unregister(&exynos4_tmu_driver);
+}
+module_exit(exynos4_tmu_driver_exit);
+
+MODULE_DESCRIPTION("EXYNOS4 TMU Driver");
+MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:exynos4-tmu");
diff --git a/include/linux/platform_data/exynos4_tmu.h b/include/linux/platform_data/exynos4_tmu.h
new file mode 100644
index 0000000..b98f024
--- /dev/null
+++ b/include/linux/platform_data/exynos4_tmu.h
@@ -0,0 +1,83 @@
+/*
+ * exynos4_tmu.h - Samsung EXYNOS4 TMU (Thermal Management Unit)
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *  Donggeun Kim <dg77.kim@samsung.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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * 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
+ */
+
+#ifndef _LINUX_EXYNOS4_TMU_H
+#define _LINUX_EXYNOS4_TMU_H
+
+enum calibration_type {
+	TYPE_ONE_POINT_TRIMMING,
+	TYPE_TWO_POINT_TRIMMING,
+	TYPE_NONE,
+};
+
+/**
+ * struct exynos4_tmu_platform_data
+ * @threshold: basic temperature for generating interrupt
+ * @trigger_level0: terperature for trigger_level0 interrupt
+ *	condition for trigger_level0 interrupt:
+ *		current temperature > threshold + trigger_level0
+ * @trigger_level1: terperature for trigger_level1 interrupt
+ *	condition for trigger_level1 interrupt:
+ *		current temperature > threshold + trigger_level1
+ * @trigger_level2: terperature for trigger_level2 interrupt
+ *	condition for trigger_level2 interrupt:
+ *		current temperature > threshold + trigger_level2
+ * @trigger_level3: terperature for trigger_level3 interrupt
+ *	condition for trigger_level3 interrupt:
+ *		current temperature > threshold + trigger_level3
+ * @trigger_level0_en:
+ *	1 = enable trigger_level0 interrupt,
+ *	0 = disable trigger_level0 interrupt
+ * @trigger_level1_en:
+ *	1 = enable trigger_level1 interrupt,
+ *	0 = disable trigger_level1 interrupt
+ * @trigger_level2_en:
+ *	1 = enable trigger_level2 interrupt,
+ *	0 = disable trigger_level2 interrupt
+ * @trigger_level3_en:
+ *	1 = enable trigger_level3 interrupt,
+ *	0 = disable trigger_level3 interrupt
+ * @gain: gain of amplifier in the positive-TC generator block
+ *	0 <= gain <= 15
+ * @reference_voltage: reference voltage of amplifier
+ *	in the positive-TC generator block
+ *	0 <= reference_voltage <= 31
+ * @cal_type: calibration type for temperature
+ *
+ * This structure is required for configuration of exynos4_tmu driver.
+ */
+struct exynos4_tmu_platform_data {
+	u8 threshold;
+	u8 trigger_level0;
+	u8 trigger_level1;
+	u8 trigger_level2;
+	u8 trigger_level3;
+	bool trigger_level0_en;
+	bool trigger_level1_en;
+	bool trigger_level2_en;
+	bool trigger_level3_en;
+
+	u8 gain;
+	u8 reference_voltage;
+
+	enum calibration_type cal_type;
+};
+#endif /* _LINUX_EXYNOS4_TMU_H */
-- 
1.7.4.1


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^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU
  2011-08-25  8:13 [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU Donggeun Kim
@ 2011-08-25  9:17 ` Jean Delvare
  2011-08-25 16:26 ` Guenter Roeck
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 5+ messages in thread
From: Jean Delvare @ 2011-08-25  9:17 UTC (permalink / raw)
  To: lm-sensors

Hi Kim,

On Thu, 25 Aug 2011 17:13:54 +0900, Donggeun Kim wrote:
> This patch allows to read temperature
> from TMU(Thermal Management Unit) of SAMSUNG EXYNOS4 series of SoC.
> 
> Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  Documentation/hwmon/exynos4_tmu           |   66 ++++
>  drivers/hwmon/Kconfig                     |   10 +
>  drivers/hwmon/Makefile                    |    1 +
>  drivers/hwmon/exynos4_tmu.c               |  478 +++++++++++++++++++++++++++++
>  include/linux/platform_data/exynos4_tmu.h |   83 +++++
>  5 files changed, 638 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/hwmon/exynos4_tmu
>  create mode 100644 drivers/hwmon/exynos4_tmu.c
>  create mode 100644 include/linux/platform_data/exynos4_tmu.h

I don't have time for a full review at the moment, but one thing stood
out so I'm commenting on that:

> +temp1_alarm	shows which interrupt threshold level is met
> +		1: current temperature exceeds level_0
> +		10: current temperature exceeds level_1
> +		100: current temperature exceeds level_2
> +		1000: current temperature exceeds level_3
> +		RO

This doesn't fit in the standard interface described in
Documentation/hwmon/sysfs-interface and will thus not be accepted.

Unfortunately the best you can do with the standard interface is 3
limits, not four. So you'd have:

temp1_max_alarm
temp1_crit_alarm
temp1_emergency_alarm

so you'll have to omit one of the levels, or map two levels to one
alarm file. These alarm files can only return 0 or 1.

BTW it would be great if you could also implement the corresponding
temp1_max, temp1_crit and temp1_emergency files, at least read-only,
otherwise the alarm files aren't so useful.

-- 
Jean Delvare

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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU
  2011-08-25  8:13 [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU Donggeun Kim
  2011-08-25  9:17 ` Jean Delvare
@ 2011-08-25 16:26 ` Guenter Roeck
  2011-08-26  2:08 ` Donggeun Kim
  2011-08-26  2:20 ` Donggeun Kim
  3 siblings, 0 replies; 5+ messages in thread
From: Guenter Roeck @ 2011-08-25 16:26 UTC (permalink / raw)
  To: lm-sensors

On Thu, 2011-08-25 at 04:13 -0400, Donggeun Kim wrote:
> This patch allows to read temperature
> from TMU(Thermal Management Unit) of SAMSUNG EXYNOS4 series of SoC.
> 
> Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  Documentation/hwmon/exynos4_tmu           |   66 ++++
>  drivers/hwmon/Kconfig                     |   10 +
>  drivers/hwmon/Makefile                    |    1 +
>  drivers/hwmon/exynos4_tmu.c               |  478 +++++++++++++++++++++++++++++
>  include/linux/platform_data/exynos4_tmu.h |   83 +++++
>  5 files changed, 638 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/hwmon/exynos4_tmu
>  create mode 100644 drivers/hwmon/exynos4_tmu.c
>  create mode 100644 include/linux/platform_data/exynos4_tmu.h
> 
> diff --git a/Documentation/hwmon/exynos4_tmu b/Documentation/hwmon/exynos4_tmu
> new file mode 100644
> index 0000000..27d8ab6
> --- /dev/null
> +++ b/Documentation/hwmon/exynos4_tmu
> @@ -0,0 +1,66 @@
> +Kernel driver exynos4_tmu
> +========> +
> +Supported chips:
> +* ARM SAMSUNG EXYNOS4 series of SoC
> +  Prefix: 'exynos4-tmu'
> +  Datasheet: Not publicly available
> +
> +Authors: Donggeun Kim <dg77.kim@samsung.com>
> +
> +Description
> +-----------
> +
> +This driver allows to read temperature inside SAMSUNG EXYNOS4 series of SoC.
> +
> +The chip only exposes the measured 8-bit temperature code value
> +through a register.
> +Temperature can be taken from the temperature code.
> +There are three equations converting from temperature to temperature code.
> +
> +The three equations are:
> +  1. Two point trimming
> +       Tc = (T - 25) * (TI2 - TI1) / (85 - 25) + TI1
> +
> +  2. One point trimming
> +       Tc = T + TI1 - 25
> +
> +  3. No trimming
> +       Tc = T + 50
> +
> +  Tc: Temperature code, T: Temperature,
> +  TI1: Trimming info for 25 degree Celsius (stored at TRIMINFO register)
> +       Temperature code measured at 25 degree Celsius which is unchanged
> +  TI2: Trimming info for 85 degree Celsius (stored at TRIMINFO register)
> +       Temperature code measured at 85 degree Celsius which is unchanged
> +
> +TMU(Thermal Management Unit) in EXYNOS4 generates interrupt
> +when temperature exceeds pre-defined levels.
> +The maximum number of configurable threshold is four.
> +The threshold levels are defined as follows:
> +  Level_0: current temperature > trigger_level_0 + threshold
> +  Level_1: current temperature > trigger_level_1 + threshold
> +  Level_2: current temperature > trigger_level_2 + threshold
> +  Level_3: current temperature > trigger_level_3 + threshold
> +
> +  The threshold and each trigger_level are set
> +  through the corresponding registers.
> +
> +When an interrupt occurs, this driver notify user space of
> +one of four threshold levels for the interrupt
> +through kobject_uevent_env and sysfs_notify functions.
> +
> +Sysfs Interface
> +---------------
> +name           name of the temperature sensor
> +               RO
> +
> +temp1_input    temperature
> +               RO
> +
> +temp1_alarm    shows which interrupt threshold level is met
> +               1: current temperature exceeds level_0
> +               10: current temperature exceeds level_1
> +               100: current temperature exceeds level_2
> +               1000: current temperature exceeds level_3
> +               RO
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 0b62c3c..c6fb761 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -303,6 +303,16 @@ config SENSORS_DS1621
>           This driver can also be built as a module.  If so, the module
>           will be called ds1621.
> 
> +config SENSORS_EXYNOS4_TMU
> +       tristate "Temperature sensor on Samsung EXYNOS4"
> +       depends on EXYNOS4_DEV_TMU
> +       help
> +         If you say yes here you get support for TMU (Thermal Managment
> +         Unit) on SAMSUNG EXYNOS4 series of SoC.
> +
> +         This driver can also be built as a module. If so, the module
> +         will be called exynos4-tmu.
> +
>  config SENSORS_I5K_AMB
>         tristate "FB-DIMM AMB temperature sensor on Intel 5000 series chipsets"
>         depends on PCI && EXPERIMENTAL
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 3c9ccef..dbd8963 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -47,6 +47,7 @@ obj-$(CONFIG_SENSORS_DS1621)  += ds1621.o
>  obj-$(CONFIG_SENSORS_EMC1403)  += emc1403.o
>  obj-$(CONFIG_SENSORS_EMC2103)  += emc2103.o
>  obj-$(CONFIG_SENSORS_EMC6W201) += emc6w201.o
> +obj-$(CONFIG_SENSORS_EXYNOS4_TMU)      += exynos4_tmu.o
>  obj-$(CONFIG_SENSORS_F71805F)  += f71805f.o
>  obj-$(CONFIG_SENSORS_F71882FG) += f71882fg.o
>  obj-$(CONFIG_SENSORS_F75375S)  += f75375s.o
> diff --git a/drivers/hwmon/exynos4_tmu.c b/drivers/hwmon/exynos4_tmu.c
> new file mode 100644
> index 0000000..b433c47
> --- /dev/null
> +++ b/drivers/hwmon/exynos4_tmu.c
> @@ -0,0 +1,478 @@
> +/*
> + * exynos4_tmu.c - Samsung EXYNOS4 TMU (Thermal Management Unit)
> + *
> + *  Copyright (C) 2011 Samsung Electronics
> + *  Donggeun Kim <dg77.kim@samsung.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; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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.
> + *
> + * 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 <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/interrupt.h>
> +#include <linux/clk.h>
> +#include <linux/workqueue.h>
> +#include <linux/sysfs.h>
> +#include <linux/kobject.h>
> +#include <linux/io.h>
> +
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +
> +#include <linux/platform_data/exynos4_tmu.h>
> +
> +#define EXYNOS4_TMU_REG_TRIMINFO       0x0
> +#define EXYNOS4_TMU_REG_CONTROL                0x20
> +#define EXYNOS4_TMU_REG_STATUS         0x28
> +#define EXYNOS4_TMU_REG_CURRENT_TEMP   0x40
> +#define EXYNOS4_TMU_REG_THRESHOLD_TEMP 0x44
> +#define EXYNOS4_TMU_REG_TRIG_LEVEL0    0x50
> +#define EXYNOS4_TMU_REG_TRIG_LEVEL1    0x54
> +#define EXYNOS4_TMU_REG_TRIG_LEVEL2    0x58
> +#define EXYNOS4_TMU_REG_TRIG_LEVEL3    0x5C
> +#define EXYNOS4_TMU_REG_PAST_TEMP0     0x60
> +#define EXYNOS4_TMU_REG_PAST_TEMP1     0x64
> +#define EXYNOS4_TMU_REG_PAST_TEMP2     0x68
> +#define EXYNOS4_TMU_REG_PAST_TEMP3     0x6C
> +#define EXYNOS4_TMU_REG_INTEN          0x70
> +#define EXYNOS4_TMU_REG_INTSTAT                0x74
> +#define EXYNOS4_TMU_REG_INTCLEAR       0x78
> +
> +#define EXYNOS4_TMU_GAIN_SHIFT         8
> +#define EXYNOS4_TMU_REF_VOLTAGE_SHIFT  24
> +
> +#define EXYNOS4_TMU_TRIM_TEMP_MASK     0xff
> +#define EXYNOS4_TMU_CORE_ON    3
> +#define EXYNOS4_TMU_CORE_OFF   2
> +#define EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET    50
> +#define EXYNOS4_TMU_TRIG_LEVEL0_MASK   0x1
> +#define EXYNOS4_TMU_TRIG_LEVEL1_MASK   0x10
> +#define EXYNOS4_TMU_TRIG_LEVEL2_MASK   0x100
> +#define EXYNOS4_TMU_TRIG_LEVEL3_MASK   0x1000
> +#define EXYNOS4_TMU_INTCLEAR_VAL       0x1111
> +
> +struct exynos4_tmu_data {
> +       struct exynos4_tmu_platform_data *pdata;
> +       struct device *hwmon_dev;
> +       struct resource *mem;
> +       void __iomem *base;
> +       int irq;
> +       struct work_struct irq_work;
> +       struct clk *clk;
> +       unsigned int interrupt_stat;
> +       u8 temp_error1, temp_error2;
> +};
> +
> +/*
> + * TMU treats temperature as a mapped temperature code.
> + * The temperature is converted differently depending on the calibration type.
> + */
> +static u8 translate_temp_to_code(struct exynos4_tmu_data *data, u8 temp)
> +{
> +       struct exynos4_tmu_platform_data *pdata = data->pdata;
> +       unsigned int temp_code;
> +
> +       switch (pdata->cal_type) {
> +       case TYPE_TWO_POINT_TRIMMING:
> +               temp_code = (temp - 25) *
> +                   (data->temp_error2 - data->temp_error1) /
> +                   (85 - 25) + data->temp_error1;
> +               break;
> +       case TYPE_ONE_POINT_TRIMMING:
> +               temp_code = temp + data->temp_error1 - 25;
> +               break;
> +       default:
> +               temp_code = temp + EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET;
> +               break;
> +       }
> +
> +       return temp_code;
> +}
> +
> +/*
> + * Calculate a temperature value from a temperature code.
> + * The unit of the temperature is degree Celsius.
> + */
> +static u8 translate_code_to_temp(struct exynos4_tmu_data *data, u8 temp_code)
> +{
> +       struct exynos4_tmu_platform_data *pdata = data->pdata;
> +       unsigned int temp;
> +
> +       switch (pdata->cal_type) {
> +       case TYPE_TWO_POINT_TRIMMING:
> +               temp = (temp_code - data->temp_error1) * (85 - 25) /
> +                   (data->temp_error2 - data->temp_error1) + 25;
> +               break;
> +       case TYPE_ONE_POINT_TRIMMING:
> +               temp = temp_code - data->temp_error1 + 25;
> +               break;
> +       default:
> +               temp = temp_code - EXYNOS4_TMU_DEF_CODE_TO_TEMP_OFFSET;
> +               break;
> +       }
> +
> +       return temp;
> +}
> +
> +static void exynos4_tmu_initialize(struct platform_device *pdev)
> +{
> +       struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
> +       struct exynos4_tmu_platform_data *pdata = data->pdata;
> +       unsigned int status, trim_info, interrupt_en;
> +       u8 threshold_code;
> +
> +       clk_enable(data->clk);
> +
> +       status = readb(data->base + EXYNOS4_TMU_REG_STATUS);
> +       if (!status) {
> +               printk(KERN_INFO "TMU is busy\n");

Please use dev_info(&pdev->dev, ...);

> +               clk_disable(data->clk);
> +               return;

Are you sure it is a good idea to ignore this error ? Limits won't be
set, threshold won't be set, trigger levels won't be set. In other
words, the chip is left in a completely uninitialized and thus
unpredictable state.

It might be better to abort driver initialization if this happens.

> +       }
> +
> +       /* Save trimming info in order to perform calibration */
> +       trim_info = readl(data->base + EXYNOS4_TMU_REG_TRIMINFO);
> +       data->temp_error1 = trim_info & EXYNOS4_TMU_TRIM_TEMP_MASK;
> +       data->temp_error2 = ((trim_info >> 8) & EXYNOS4_TMU_TRIM_TEMP_MASK);
> +
> +       /* Write temperature code for threshold */
> +       threshold_code = translate_temp_to_code(data, pdata->threshold);
> +       writeb(threshold_code,
> +               data->base + EXYNOS4_TMU_REG_THRESHOLD_TEMP);
> +
> +       writeb(pdata->trigger_level0,
> +               data->base + EXYNOS4_TMU_REG_TRIG_LEVEL0);
> +       writeb(pdata->trigger_level1,
> +               data->base + EXYNOS4_TMU_REG_TRIG_LEVEL1);
> +       writeb(pdata->trigger_level2,
> +               data->base + EXYNOS4_TMU_REG_TRIG_LEVEL2);
> +       writeb(pdata->trigger_level3,
> +               data->base + EXYNOS4_TMU_REG_TRIG_LEVEL3);
> +
> +       writel(EXYNOS4_TMU_INTCLEAR_VAL,
> +               data->base + EXYNOS4_TMU_REG_INTCLEAR);
> +
> +       interrupt_en = pdata->trigger_level3_en << 12 |
> +               pdata->trigger_level2_en << 8 |
> +               pdata->trigger_level1_en << 4 |
> +               pdata->trigger_level0_en;
> +       writel(interrupt_en, data->base + EXYNOS4_TMU_REG_INTEN);
> +
> +       clk_disable(data->clk);
> +}
> +
> +static void exynos4_tmu_control(struct platform_device *pdev, bool on)
> +{
> +       struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
> +       struct exynos4_tmu_platform_data *pdata = data->pdata;
> +       unsigned int con;
> +
> +       clk_enable(data->clk);
> +
> +       con = pdata->reference_voltage << EXYNOS4_TMU_REF_VOLTAGE_SHIFT |
> +               pdata->gain << EXYNOS4_TMU_GAIN_SHIFT;
> +       if (on)
> +               con |= EXYNOS4_TMU_CORE_ON;
> +       else
> +               con |= EXYNOS4_TMU_CORE_OFF;
> +
> +       writel(con, data->base + EXYNOS4_TMU_REG_CONTROL);
> +
> +       clk_disable(data->clk);
> +}
> +
> +static int exynos4_tmu_read(struct exynos4_tmu_data *data, u8 *temp)
> +{
> +       u8 temp_code;
> +
> +       clk_enable(data->clk);
> +
> +       temp_code = readb(data->base + EXYNOS4_TMU_REG_CURRENT_TEMP);
> +       if (!temp_code) {
> +               dev_err(data->hwmon_dev, "Failed to read temperature code\n");

dev_err and EAGAIN ? Is this really necessary ? EAGAIN will result in a
retry; if the condition is permanent you'll fill the log pretty quickly.

> +               clk_disable(data->clk);
> +               return -EAGAIN;
> +       }
> +       *temp = translate_code_to_temp(data, temp_code);
> +
> +       clk_disable(data->clk);
> +
> +       return 0;
> +}
> +
> +static void exynos4_tmu_work(struct work_struct *work)
> +{
> +       struct exynos4_tmu_data *data = container_of(work,
> +                       struct exynos4_tmu_data, irq_work);
> +       char *envp[2];
> +
> +       clk_enable(data->clk);
> +
> +       data->interrupt_stat = readl(data->base + EXYNOS4_TMU_REG_INTSTAT);
> +
> +       writel(EXYNOS4_TMU_INTCLEAR_VAL, data->base + EXYNOS4_TMU_REG_INTCLEAR);
> +
> +       if (data->interrupt_stat & EXYNOS4_TMU_TRIG_LEVEL3_MASK)
> +               envp[0] = "TRIG_LEVEL=3";
> +       else if (data->interrupt_stat & EXYNOS4_TMU_TRIG_LEVEL2_MASK)
> +               envp[0] = "TRIG_LEVEL=2";
> +       else if (data->interrupt_stat & EXYNOS4_TMU_TRIG_LEVEL1_MASK)
> +               envp[0] = "TRIG_LEVEL=1";
> +       else
> +               envp[0] = "TRIG_LEVEL=0";
> +       envp[1] = NULL;
> +
> +       sysfs_notify(&data->hwmon_dev->kobj, NULL, "temp1_alarm");
> +       kobject_uevent_env(&data->hwmon_dev->kobj, KOBJ_CHANGE, envp);
> +       enable_irq(data->irq);
> +
> +       clk_disable(data->clk);
> +}
> +
> +static irqreturn_t exynos4_tmu_irq(int irq, void *id)
> +{
> +       struct exynos4_tmu_data *data = id;
> +
> +       if (!work_pending(&data->irq_work)) {
> +               disable_irq_nosync(irq);
> +               schedule_work(&data->irq_work);
> +       } else {
> +               dev_err(data->hwmon_dev, "irq_work pending\n");
> +       }
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static ssize_t exynos4_tmu_show_name(struct device *dev,
> +               struct device_attribute *attr, char *buf)
> +{
> +       return sprintf(buf, "exynos4-tmu\n");
> +}
> +
> +static ssize_t exynos4_tmu_show_temp(struct device *dev,
> +               struct device_attribute *attr, char *buf)
> +{
> +       struct exynos4_tmu_data *data = dev_get_drvdata(dev);
> +       int ret;
> +       u8 temp;
> +
> +       ret = exynos4_tmu_read(data, &temp);
> +       if (ret)
> +               return ret;
> +       /* convert from degree Celsius to millidegree Celsius */
> +       return sprintf(buf, "%d\n", temp * 1000);
> +}
> +
> +static ssize_t exynos4_tmu_show_alarm(struct device *dev,
> +               struct device_attribute *attr, char *buf)
> +{
> +       struct exynos4_tmu_data *data = dev_get_drvdata(dev);
> +
> +       /*
> +        * 1: trigger_level0 interrupt generated
> +        * 10: trigger_level1 interrupt generated
> +        * 100: trigger_level2 interrupt generated
> +        * 1000: trigger_level3 interrupt generated
> +        */
> +       return sprintf(buf, "%x\n", data->interrupt_stat);
> +}
> +
> +static DEVICE_ATTR(name, S_IRUGO, exynos4_tmu_show_name, NULL);
> +static DEVICE_ATTR(temp1_alarm, S_IRUGO, exynos4_tmu_show_alarm, NULL);
> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, exynos4_tmu_show_temp, NULL, 0);
> +
> +static struct attribute *exynos4_tmu_attributes[] = {
> +       &dev_attr_name.attr,
> +       &dev_attr_temp1_alarm.attr,
> +       &sensor_dev_attr_temp1_input.dev_attr.attr,
> +       NULL,
> +};
> +
> +static const struct attribute_group exynos4_tmu_attr_group = {
> +       .attrs = exynos4_tmu_attributes,
> +};
> +
> +static int __devinit exynos4_tmu_probe(struct platform_device *pdev)
> +{
> +       struct exynos4_tmu_data *data;
> +       struct exynos4_tmu_platform_data *pdata = pdev->dev.platform_data;
> +       int ret;
> +
> +       if (!pdata) {
> +               dev_err(&pdev->dev, "No platform init data supplied.\n");
> +               return -ENODEV;
> +       }
> +
> +       data = kzalloc(sizeof(struct exynos4_tmu_data), GFP_KERNEL);
> +       if (!data) {
> +               dev_err(&pdev->dev, "Failed to allocate driver structure\n");
> +               return -ENOMEM;
> +       }
> +
> +       data->irq = platform_get_irq(pdev, 0);
> +       if (data->irq < 0) {
> +               ret = data->irq;
> +               dev_err(&pdev->dev, "Failed to get platform irq1\n");
> +               goto err_free;
> +       }
> +
> +       INIT_WORK(&data->irq_work, exynos4_tmu_work);
> +
> +       data->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!data->mem) {
> +               ret = -ENOENT;
> +               dev_err(&pdev->dev, "Failed to get platform resource\n");
> +               goto err_free;
> +       }
> +
> +       data->mem = request_mem_region(data->mem->start,
> +                       resource_size(data->mem), pdev->name);
> +       if (!data->mem) {
> +               ret = -EBUSY;
> +               dev_err(&pdev->dev, "Failed to request memory region\n");
> +               goto err_free;
> +       }
> +
> +       data->base = ioremap(data->mem->start, resource_size(data->mem));
> +       if (!data->base) {
> +               ret = -EBUSY;
> +               dev_err(&pdev->dev, "Failed to ioremap memory\n");
> +               goto err_mem_region;
> +       }
> +
> +       ret = request_irq(data->irq, exynos4_tmu_irq,
> +               IRQF_DISABLED | IRQF_TRIGGER_RISING,
> +               "exynos4-tmu", data);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
> +               goto err_io_remap;
> +       }
> +
> +       data->clk = clk_get(NULL, "tmu_apbif");
> +       if (IS_ERR(data->clk)) {
> +               ret = -EINVAL;
> +               dev_err(&pdev->dev, "Failed to get clock\n");
> +               goto err_irq;
> +       }
> +
> +       data->pdata = pdata;
> +       platform_set_drvdata(pdev, data);
> +
> +       ret = sysfs_create_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
> +               goto err_clk;
> +       }
> +
> +       data->hwmon_dev = hwmon_device_register(&pdev->dev);
> +       if (IS_ERR(data->hwmon_dev)) {
> +               ret = PTR_ERR(data->hwmon_dev);
> +               goto err_create_group;
> +       }
> +
> +       exynos4_tmu_initialize(pdev);
> +       exynos4_tmu_control(pdev, true);
> +
> +       return 0;
> +
> +err_create_group:
> +       sysfs_remove_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
> +err_clk:
> +       platform_set_drvdata(pdev, NULL);
> +       clk_put(data->clk);
> +err_irq:
> +       free_irq(data->irq, data);
> +err_io_remap:
> +       iounmap(data->base);
> +err_mem_region:
> +       release_mem_region(data->mem->start, resource_size(data->mem));
> +err_free:
> +       kfree(data);
> +
> +       return ret;
> +}
> +
> +static int __devexit exynos4_tmu_remove(struct platform_device *pdev)
> +{
> +       struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
> +
> +       hwmon_device_unregister(data->hwmon_dev);
> +       sysfs_remove_group(&pdev->dev.kobj, &exynos4_tmu_attr_group);
> +
> +       clk_put(data->clk);
> +
> +       free_irq(data->irq, data);
> +
> +       iounmap(data->base);
> +       release_mem_region(data->mem->start, resource_size(data->mem));
> +
> +       platform_set_drvdata(pdev, NULL);
> +
> +       kfree(data);
> +
> +       return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int exynos4_tmu_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> +       exynos4_tmu_control(pdev, false);
> +
> +       return 0;
> +}
> +
> +static int exynos4_tmu_resume(struct platform_device *pdev)
> +{
> +       exynos4_tmu_initialize(pdev);
> +       exynos4_tmu_control(pdev, true);
> +
> +       return 0;
> +}
> +#else
> +#define exynos4_tmu_suspend NULL
> +#define exynos4_tmu_resume NULL
> +#endif
> +
> +static struct platform_driver exynos4_tmu_driver = {
> +       .driver = {
> +               .name   = "exynos4-tmu",
> +               .owner  = THIS_MODULE,
> +       },
> +       .probe = exynos4_tmu_probe,
> +       .remove = __devexit_p(exynos4_tmu_remove),
> +       .suspend = exynos4_tmu_suspend,
> +       .resume = exynos4_tmu_resume,
> +};
> +
> +static int __init exynos4_tmu_driver_init(void)
> +{
> +       return platform_driver_register(&exynos4_tmu_driver);
> +}
> +module_init(exynos4_tmu_driver_init);
> +
> +static void __exit exynos4_tmu_driver_exit(void)
> +{
> +       platform_driver_unregister(&exynos4_tmu_driver);
> +}
> +module_exit(exynos4_tmu_driver_exit);
> +
> +MODULE_DESCRIPTION("EXYNOS4 TMU Driver");
> +MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:exynos4-tmu");
> diff --git a/include/linux/platform_data/exynos4_tmu.h b/include/linux/platform_data/exynos4_tmu.h
> new file mode 100644
> index 0000000..b98f024
> --- /dev/null
> +++ b/include/linux/platform_data/exynos4_tmu.h
> @@ -0,0 +1,83 @@
> +/*
> + * exynos4_tmu.h - Samsung EXYNOS4 TMU (Thermal Management Unit)
> + *
> + *  Copyright (C) 2011 Samsung Electronics
> + *  Donggeun Kim <dg77.kim@samsung.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; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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.
> + *
> + * 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
> + */
> +
> +#ifndef _LINUX_EXYNOS4_TMU_H
> +#define _LINUX_EXYNOS4_TMU_H
> +
> +enum calibration_type {
> +       TYPE_ONE_POINT_TRIMMING,
> +       TYPE_TWO_POINT_TRIMMING,
> +       TYPE_NONE,
> +};
> +
> +/**
> + * struct exynos4_tmu_platform_data
> + * @threshold: basic temperature for generating interrupt
> + * @trigger_level0: terperature for trigger_level0 interrupt
> + *     condition for trigger_level0 interrupt:
> + *             current temperature > threshold + trigger_level0
> + * @trigger_level1: terperature for trigger_level1 interrupt
> + *     condition for trigger_level1 interrupt:
> + *             current temperature > threshold + trigger_level1
> + * @trigger_level2: terperature for trigger_level2 interrupt
> + *     condition for trigger_level2 interrupt:
> + *             current temperature > threshold + trigger_level2
> + * @trigger_level3: terperature for trigger_level3 interrupt
> + *     condition for trigger_level3 interrupt:
> + *             current temperature > threshold + trigger_level3
> + * @trigger_level0_en:
> + *     1 = enable trigger_level0 interrupt,
> + *     0 = disable trigger_level0 interrupt
> + * @trigger_level1_en:
> + *     1 = enable trigger_level1 interrupt,
> + *     0 = disable trigger_level1 interrupt
> + * @trigger_level2_en:
> + *     1 = enable trigger_level2 interrupt,
> + *     0 = disable trigger_level2 interrupt
> + * @trigger_level3_en:
> + *     1 = enable trigger_level3 interrupt,
> + *     0 = disable trigger_level3 interrupt
> + * @gain: gain of amplifier in the positive-TC generator block
> + *     0 <= gain <= 15
> + * @reference_voltage: reference voltage of amplifier
> + *     in the positive-TC generator block
> + *     0 <= reference_voltage <= 31
> + * @cal_type: calibration type for temperature
> + *
> + * This structure is required for configuration of exynos4_tmu driver.
> + */
> +struct exynos4_tmu_platform_data {
> +       u8 threshold;
> +       u8 trigger_level0;
> +       u8 trigger_level1;
> +       u8 trigger_level2;
> +       u8 trigger_level3;
> +       bool trigger_level0_en;
> +       bool trigger_level1_en;
> +       bool trigger_level2_en;
> +       bool trigger_level3_en;
> +
> +       u8 gain;
> +       u8 reference_voltage;
> +
> +       enum calibration_type cal_type;
> +};
> +#endif /* _LINUX_EXYNOS4_TMU_H */
> --
> 1.7.4.1
> 



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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU
  2011-08-25  8:13 [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU Donggeun Kim
  2011-08-25  9:17 ` Jean Delvare
  2011-08-25 16:26 ` Guenter Roeck
@ 2011-08-26  2:08 ` Donggeun Kim
  2011-08-26  2:20 ` Donggeun Kim
  3 siblings, 0 replies; 5+ messages in thread
From: Donggeun Kim @ 2011-08-26  2:08 UTC (permalink / raw)
  To: lm-sensors

On 2011년 08월 25일 18:17, Jean Delvare wrote:
> Hi Kim,
> 
> On Thu, 25 Aug 2011 17:13:54 +0900, Donggeun Kim wrote:
>> This patch allows to read temperature
>> from TMU(Thermal Management Unit) of SAMSUNG EXYNOS4 series of SoC.
>>
>> Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
>> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>>  Documentation/hwmon/exynos4_tmu           |   66 ++++
>>  drivers/hwmon/Kconfig                     |   10 +
>>  drivers/hwmon/Makefile                    |    1 +
>>  drivers/hwmon/exynos4_tmu.c               |  478 +++++++++++++++++++++++++++++
>>  include/linux/platform_data/exynos4_tmu.h |   83 +++++
>>  5 files changed, 638 insertions(+), 0 deletions(-)
>>  create mode 100644 Documentation/hwmon/exynos4_tmu
>>  create mode 100644 drivers/hwmon/exynos4_tmu.c
>>  create mode 100644 include/linux/platform_data/exynos4_tmu.h
> 
> I don't have time for a full review at the moment, but one thing stood
> out so I'm commenting on that:
> 
>> +temp1_alarm	shows which interrupt threshold level is met
>> +		1: current temperature exceeds level_0
>> +		10: current temperature exceeds level_1
>> +		100: current temperature exceeds level_2
>> +		1000: current temperature exceeds level_3
>> +		RO
> 
> This doesn't fit in the standard interface described in
> Documentation/hwmon/sysfs-interface and will thus not be accepted.
> 
> Unfortunately the best you can do with the standard interface is 3
> limits, not four. So you'd have:
> 
> temp1_max_alarm
> temp1_crit_alarm
> temp1_emergency_alarm
> 
> so you'll have to omit one of the levels, or map two levels to one
> alarm file. These alarm files can only return 0 or 1.
> 
> BTW it would be great if you could also implement the corresponding
> temp1_max, temp1_crit and temp1_emergency files, at least read-only,
> otherwise the alarm files aren't so useful.
> 
I will add the mentioned files in the next patch.
Thank you for your review.


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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU
  2011-08-25  8:13 [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU Donggeun Kim
                   ` (2 preceding siblings ...)
  2011-08-26  2:08 ` Donggeun Kim
@ 2011-08-26  2:20 ` Donggeun Kim
  3 siblings, 0 replies; 5+ messages in thread
From: Donggeun Kim @ 2011-08-26  2:20 UTC (permalink / raw)
  To: lm-sensors

On 2011년 08월 26일 01:26, Guenter Roeck wrote:
> On Thu, 2011-08-25 at 04:13 -0400, Donggeun Kim wrote:
>> +static void exynos4_tmu_initialize(struct platform_device *pdev)
>> +{
>> +       struct exynos4_tmu_data *data = platform_get_drvdata(pdev);
>> +       struct exynos4_tmu_platform_data *pdata = data->pdata;
>> +       unsigned int status, trim_info, interrupt_en;
>> +       u8 threshold_code;
>> +
>> +       clk_enable(data->clk);
>> +
>> +       status = readb(data->base + EXYNOS4_TMU_REG_STATUS);
>> +       if (!status) {
>> +               printk(KERN_INFO "TMU is busy\n");
> 
> Please use dev_info(&pdev->dev, ...);
> 
>> +               clk_disable(data->clk);
>> +               return;
> 
> Are you sure it is a good idea to ignore this error ? Limits won't be
> set, threshold won't be set, trigger levels won't be set. In other
> words, the chip is left in a completely uninitialized and thus
> unpredictable state.
> 
> It might be better to abort driver initialization if this happens.
> 
I should have handled this as a error. I will fix it.

>> +static int exynos4_tmu_read(struct exynos4_tmu_data *data, u8 *temp)
>> +{
>> +       u8 temp_code;
>> +
>> +       clk_enable(data->clk);
>> +
>> +       temp_code = readb(data->base + EXYNOS4_TMU_REG_CURRENT_TEMP);
>> +       if (!temp_code) {
>> +               dev_err(data->hwmon_dev, "Failed to read temperature code\n");
> 
> dev_err and EAGAIN ? Is this really necessary ? EAGAIN will result in a
> retry; if the condition is permanent you'll fill the log pretty quickly.
> 
Okay, it would be better to change the error code.

Thanks for your review.



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^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2011-08-26  2:20 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-08-25  8:13 [lm-sensors] [PATCH] hwmon: Add driver for EXYNOS4 TMU Donggeun Kim
2011-08-25  9:17 ` Jean Delvare
2011-08-25 16:26 ` Guenter Roeck
2011-08-26  2:08 ` Donggeun Kim
2011-08-26  2:20 ` Donggeun Kim

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