1 files changed, 570 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel_mid_thermal.c b/drivers/platform/x86/intel_mid_thermal.c
new file mode 100644
index 000000000..008a76903
--- /dev/null
+++ b/drivers/platform/x86/intel_mid_thermal.c
@@ -0,0 +1,570 @@
+/*
+ * intel_mid_thermal.c - Intel MID platform thermal driver
+ *
+ * Copyright (C) 2011 Intel Corporation
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * Author: Durgadoss R <durgadoss.r@intel.com>
+ */
+
+#define pr_fmt(fmt) "intel_mid_thermal: " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/param.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pm.h>
+#include <linux/thermal.h>
+#include <linux/mfd/intel_msic.h>
+
+/* Number of thermal sensors */
+#define MSIC_THERMAL_SENSORS	4
+
+/* ADC1 - thermal registers */
+#define MSIC_ADC_ENBL		0x10
+#define MSIC_ADC_START		0x08
+
+#define MSIC_ADCTHERM_ENBL	0x04
+#define MSIC_ADCRRDATA_ENBL	0x05
+#define MSIC_CHANL_MASK_VAL	0x0F
+
+#define MSIC_STOPBIT_MASK	16
+#define MSIC_ADCTHERM_MASK	4
+/* Number of ADC channels */
+#define ADC_CHANLS_MAX		15
+#define ADC_LOOP_MAX		(ADC_CHANLS_MAX - MSIC_THERMAL_SENSORS)
+
+/* ADC channel code values */
+#define SKIN_SENSOR0_CODE	0x08
+#define SKIN_SENSOR1_CODE	0x09
+#define SYS_SENSOR_CODE		0x0A
+#define MSIC_DIE_SENSOR_CODE	0x03
+
+#define SKIN_THERM_SENSOR0	0
+#define SKIN_THERM_SENSOR1	1
+#define SYS_THERM_SENSOR2	2
+#define MSIC_DIE_THERM_SENSOR3	3
+
+/* ADC code range */
+#define ADC_MAX			977
+#define ADC_MIN			162
+#define ADC_VAL0C		887
+#define ADC_VAL20C		720
+#define ADC_VAL40C		508
+#define ADC_VAL60C		315
+
+/* ADC base addresses */
+#define ADC_CHNL_START_ADDR	INTEL_MSIC_ADC1ADDR0	/* increments by 1 */
+#define ADC_DATA_START_ADDR	INTEL_MSIC_ADC1SNS0H	/* increments by 2 */
+
+/* MSIC die attributes */
+#define MSIC_DIE_ADC_MIN	488
+#define MSIC_DIE_ADC_MAX	1004
+
+/* This holds the address of the first free ADC channel,
+ * among the 15 channels
+ */
+static int channel_index;
+
+struct platform_info {
+	struct platform_device *pdev;
+	struct thermal_zone_device *tzd[MSIC_THERMAL_SENSORS];
+};
+
+struct thermal_device_info {
+	unsigned int chnl_addr;
+	int direct;
+	/* This holds the current temperature in millidegree celsius */
+	long curr_temp;
+};
+
+/**
+ * to_msic_die_temp - converts adc_val to msic_die temperature
+ * @adc_val: ADC value to be converted
+ *
+ * Can sleep
+ */
+static int to_msic_die_temp(uint16_t adc_val)
+{
+	return (368 * (adc_val) / 1000) - 220;
+}
+
+/**
+ * is_valid_adc - checks whether the adc code is within the defined range
+ * @min: minimum value for the sensor
+ * @max: maximum value for the sensor
+ *
+ * Can sleep
+ */
+static int is_valid_adc(uint16_t adc_val, uint16_t min, uint16_t max)
+{
+	return (adc_val >= min) && (adc_val <= max);
+}
+
+/**
+ * adc_to_temp - converts the ADC code to temperature in C
+ * @direct: true if ths channel is direct index
+ * @adc_val: the adc_val that needs to be converted
+ * @tp: temperature return value
+ *
+ * Linear approximation is used to covert the skin adc value into temperature.
+ * This technique is used to avoid very long look-up table to get
+ * the appropriate temp value from ADC value.
+ * The adc code vs sensor temp curve is split into five parts
+ * to achieve very close approximate temp value with less than
+ * 0.5C error
+ */
+static int adc_to_temp(int direct, uint16_t adc_val, int *tp)
+{
+	int temp;
+
+	/* Direct conversion for die temperature */
+	if (direct) {
+		if (is_valid_adc(adc_val, MSIC_DIE_ADC_MIN, MSIC_DIE_ADC_MAX)) {
+			*tp = to_msic_die_temp(adc_val) * 1000;
+			return 0;
+		}
+		return -ERANGE;
+	}
+
+	if (!is_valid_adc(adc_val, ADC_MIN, ADC_MAX))
+		return -ERANGE;
+
+	/* Linear approximation for skin temperature */
+	if (adc_val > ADC_VAL0C)
+		temp = 177 - (adc_val/5);
+	else if ((adc_val <= ADC_VAL0C) && (adc_val > ADC_VAL20C))
+		temp = 111 - (adc_val/8);
+	else if ((adc_val <= ADC_VAL20C) && (adc_val > ADC_VAL40C))
+		temp = 92 - (adc_val/10);
+	else if ((adc_val <= ADC_VAL40C) && (adc_val > ADC_VAL60C))
+		temp = 91 - (adc_val/10);
+	else
+		temp = 112 - (adc_val/6);
+
+	/* Convert temperature in celsius to milli degree celsius */
+	*tp = temp * 1000;
+	return 0;
+}
+
+/**
+ * mid_read_temp - read sensors for temperature
+ * @temp: holds the current temperature for the sensor after reading
+ *
+ * reads the adc_code from the channel and converts it to real
+ * temperature. The converted value is stored in temp.
+ *
+ * Can sleep
+ */
+static int mid_read_temp(struct thermal_zone_device *tzd, int *temp)
+{
+	struct thermal_device_info *td_info = tzd->devdata;
+	uint16_t adc_val, addr;
+	uint8_t data = 0;
+	int ret;
+	int curr_temp;
+
+	addr = td_info->chnl_addr;
+
+	/* Enable the msic for conversion before reading */
+	ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
+	if (ret)
+		return ret;
+
+	/* Re-toggle the RRDATARD bit (temporary workaround) */
+	ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
+	if (ret)
+		return ret;
+
+	/* Read the higher bits of data */
+	ret = intel_msic_reg_read(addr, &data);
+	if (ret)
+		return ret;
+
+	/* Shift bits to accommodate the lower two data bits */
+	adc_val = (data << 2);
+	addr++;
+
+	ret = intel_msic_reg_read(addr, &data);/* Read lower bits */
+	if (ret)
+		return ret;
+
+	/* Adding lower two bits to the higher bits */
+	data &= 03;
+	adc_val += data;
+
+	/* Convert ADC value to temperature */
+	ret = adc_to_temp(td_info->direct, adc_val, &curr_temp);
+	if (ret == 0)
+		*temp = td_info->curr_temp = curr_temp;
+	return ret;
+}
+
+/**
+ * configure_adc - enables/disables the ADC for conversion
+ * @val: zero: disables the ADC non-zero:enables the ADC
+ *
+ * Enable/Disable the ADC depending on the argument
+ *
+ * Can sleep
+ */
+static int configure_adc(int val)
+{
+	int ret;
+	uint8_t data;
+
+	ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
+	if (ret)
+		return ret;
+
+	if (val) {
+		/* Enable and start the ADC */
+		data |= (MSIC_ADC_ENBL | MSIC_ADC_START);
+	} else {
+		/* Just stop the ADC */
+		data &= (~MSIC_ADC_START);
+	}
+	return intel_msic_reg_write(INTEL_MSIC_ADC1CNTL1, data);
+}
+
+/**
+ * set_up_therm_channel - enable thermal channel for conversion
+ * @base_addr: index of free msic ADC channel
+ *
+ * Enable all the three channels for conversion
+ *
+ * Can sleep
+ */
+static int set_up_therm_channel(u16 base_addr)
+{
+	int ret;
+
+	/* Enable all the sensor channels */
+	ret = intel_msic_reg_write(base_addr, SKIN_SENSOR0_CODE);
+	if (ret)
+		return ret;
+
+	ret = intel_msic_reg_write(base_addr + 1, SKIN_SENSOR1_CODE);
+	if (ret)
+		return ret;
+
+	ret = intel_msic_reg_write(base_addr + 2, SYS_SENSOR_CODE);
+	if (ret)
+		return ret;
+
+	/* Since this is the last channel, set the stop bit
+	 * to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
+	ret = intel_msic_reg_write(base_addr + 3,
+			(MSIC_DIE_SENSOR_CODE | 0x10));
+	if (ret)
+		return ret;
+
+	/* Enable ADC and start it */
+	return configure_adc(1);
+}
+
+/**
+ * reset_stopbit - sets the stop bit to 0 on the given channel
+ * @addr: address of the channel
+ *
+ * Can sleep
+ */
+static int reset_stopbit(uint16_t addr)
+{
+	int ret;
+	uint8_t data;
+	ret = intel_msic_reg_read(addr, &data);
+	if (ret)
+		return ret;
+	/* Set the stop bit to zero */
+	return intel_msic_reg_write(addr, (data & 0xEF));
+}
+
+/**
+ * find_free_channel - finds an empty channel for conversion
+ *
+ * If the ADC is not enabled then start using 0th channel
+ * itself. Otherwise find an empty channel by looking for a
+ * channel in which the stopbit is set to 1. returns the index
+ * of the first free channel if succeeds or an error code.
+ *
+ * Context: can sleep
+ *
+ * FIXME: Ultimately the channel allocator will move into the intel_scu_ipc
+ * code.
+ */
+static int find_free_channel(void)
+{
+	int ret;
+	int i;
+	uint8_t data;
+
+	/* check whether ADC is enabled */
+	ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL1, &data);
+	if (ret)
+		return ret;
+
+	if ((data & MSIC_ADC_ENBL) == 0)
+		return 0;
+
+	/* ADC is already enabled; Looking for an empty channel */
+	for (i = 0; i < ADC_CHANLS_MAX; i++) {
+		ret = intel_msic_reg_read(ADC_CHNL_START_ADDR + i, &data);
+		if (ret)
+			return ret;
+
+		if (data & MSIC_STOPBIT_MASK) {
+			ret = i;
+			break;
+		}
+	}
+	return (ret > ADC_LOOP_MAX) ? (-EINVAL) : ret;
+}
+
+/**
+ * mid_initialize_adc - initializing the ADC
+ * @dev: our device structure
+ *
+ * Initialize the ADC for reading thermistor values. Can sleep.
+ */
+static int mid_initialize_adc(struct device *dev)
+{
+	u8  data;
+	u16 base_addr;
+	int ret;
+
+	/*
+	 * Ensure that adctherm is disabled before we
+	 * initialize the ADC
+	 */
+	ret = intel_msic_reg_read(INTEL_MSIC_ADC1CNTL3, &data);
+	if (ret)
+		return ret;
+
+	data &= ~MSIC_ADCTHERM_MASK;
+	ret = intel_msic_reg_write(INTEL_MSIC_ADC1CNTL3, data);
+	if (ret)
+		return ret;
+
+	/* Index of the first channel in which the stop bit is set */
+	channel_index = find_free_channel();
+	if (channel_index < 0) {
+		dev_err(dev, "No free ADC channels");
+		return channel_index;
+	}
+
+	base_addr = ADC_CHNL_START_ADDR + channel_index;
+
+	if (!(channel_index == 0 || channel_index == ADC_LOOP_MAX)) {
+		/* Reset stop bit for channels other than 0 and 12 */
+		ret = reset_stopbit(base_addr);
+		if (ret)
+			return ret;
+
+		/* Index of the first free channel */
+		base_addr++;
+		channel_index++;
+	}
+
+	ret = set_up_therm_channel(base_addr);
+	if (ret) {
+		dev_err(dev, "unable to enable ADC");
+		return ret;
+	}
+	dev_dbg(dev, "ADC initialization successful");
+	return ret;
+}
+
+/**
+ * initialize_sensor - sets default temp and timer ranges
+ * @index: index of the sensor
+ *
+ * Context: can sleep
+ */
+static struct thermal_device_info *initialize_sensor(int index)
+{
+	struct thermal_device_info *td_info =
+		kzalloc(sizeof(struct thermal_device_info), GFP_KERNEL);
+
+	if (!td_info)
+		return NULL;
+
+	/* Set the base addr of the channel for this sensor */
+	td_info->chnl_addr = ADC_DATA_START_ADDR + 2 * (channel_index + index);
+	/* Sensor 3 is direct conversion */
+	if (index == 3)
+		td_info->direct = 1;
+	return td_info;
+}
+
+#ifdef CONFIG_PM_SLEEP
+/**
+ * mid_thermal_resume - resume routine
+ * @dev: device structure
+ *
+ * mid thermal resume: re-initializes the adc. Can sleep.
+ */
+static int mid_thermal_resume(struct device *dev)
+{
+	return mid_initialize_adc(dev);
+}
+
+/**
+ * mid_thermal_suspend - suspend routine
+ * @dev: device structure
+ *
+ * mid thermal suspend implements the suspend functionality
+ * by stopping the ADC. Can sleep.
+ */
+static int mid_thermal_suspend(struct device *dev)
+{
+	/*
+	 * This just stops the ADC and does not disable it.
+	 * temporary workaround until we have a generic ADC driver.
+	 * If 0 is passed, it disables the ADC.
+	 */
+	return configure_adc(0);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(mid_thermal_pm,
+			 mid_thermal_suspend, mid_thermal_resume);
+
+/**
+ * read_curr_temp - reads the current temperature and stores in temp
+ * @temp: holds the current temperature value after reading
+ *
+ * Can sleep
+ */
+static int read_curr_temp(struct thermal_zone_device *tzd, int *temp)
+{
+	WARN_ON(tzd == NULL);
+	return mid_read_temp(tzd, temp);
+}
+
+/* Can't be const */
+static struct thermal_zone_device_ops tzd_ops = {
+	.get_temp = read_curr_temp,
+};
+
+/**
+ * mid_thermal_probe - mfld thermal initialize
+ * @pdev: platform device structure
+ *
+ * mid thermal probe initializes the hardware and registers
+ * all the sensors with the generic thermal framework. Can sleep.
+ */
+static int mid_thermal_probe(struct platform_device *pdev)
+{
+	static char *name[MSIC_THERMAL_SENSORS] = {
+		"skin0", "skin1", "sys", "msicdie"
+	};
+
+	int ret;
+	int i;
+	struct platform_info *pinfo;
+
+	pinfo = devm_kzalloc(&pdev->dev, sizeof(struct platform_info),
+			     GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	/* Initializing the hardware */
+	ret = mid_initialize_adc(&pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "ADC init failed");
+		return ret;
+	}
+
+	/* Register each sensor with the generic thermal framework*/
+	for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
+		struct thermal_device_info *td_info = initialize_sensor(i);
+
+		if (!td_info) {
+			ret = -ENOMEM;
+			goto err;
+		}
+		pinfo->tzd[i] = thermal_zone_device_register(name[i],
+				0, 0, td_info, &tzd_ops, NULL, 0, 0);
+		if (IS_ERR(pinfo->tzd[i])) {
+			kfree(td_info);
+			ret = PTR_ERR(pinfo->tzd[i]);
+			goto err;
+		}
+	}
+
+	pinfo->pdev = pdev;
+	platform_set_drvdata(pdev, pinfo);
+	return 0;
+
+err:
+	while (--i >= 0) {
+		kfree(pinfo->tzd[i]->devdata);
+		thermal_zone_device_unregister(pinfo->tzd[i]);
+	}
+	configure_adc(0);
+	return ret;
+}
+
+/**
+ * mid_thermal_remove - mfld thermal finalize
+ * @dev: platform device structure
+ *
+ * MLFD thermal remove unregisters all the sensors from the generic
+ * thermal framework. Can sleep.
+ */
+static int mid_thermal_remove(struct platform_device *pdev)
+{
+	int i;
+	struct platform_info *pinfo = platform_get_drvdata(pdev);
+
+	for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
+		kfree(pinfo->tzd[i]->devdata);
+		thermal_zone_device_unregister(pinfo->tzd[i]);
+	}
+
+	/* Stop the ADC */
+	return configure_adc(0);
+}
+
+#define DRIVER_NAME "msic_thermal"
+
+static const struct platform_device_id therm_id_table[] = {
+	{ DRIVER_NAME, 1 },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, therm_id_table);
+
+static struct platform_driver mid_thermal_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.pm = &mid_thermal_pm,
+	},
+	.probe = mid_thermal_probe,
+	.remove = mid_thermal_remove,
+	.id_table = therm_id_table,
+};
+
+module_platform_driver(mid_thermal_driver);
+
+MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
+MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
+MODULE_LICENSE("GPL");