medfield: Add Thermal Driver

This is the basic thermal sensor driver for Intel MID platform using the Medfield chipset. It plugs in via the thermal drivers and provides sensor readings for the device sensors. Signed-off-by: Durgadoss R <durgadoss.r@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Matthew Garrett <mjg@redhat.com>

medfield: Add Thermal Driver
This is the basic thermal sensor driver for Intel MID platform using the Medfield chipset. It plugs in via the thermal drivers and provides sensor readings for the device sensors. Signed-off-by: Durgadoss R <durgadoss.r@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Matthew Garrett <mjg@redhat.com>
Durgadoss R · Matthew Garrett
1 parent c0b9c64944
Showing 3 changed files with 584 additions and 1 deletions Side-by-side Diff
drivers/platform/x86/Kconfig
drivers/platform/x86/Makefile
drivers/platform/x86/intel_mid_thermal.c
@@ -637,6 +637,13 @@
  
 	  If unsure, say N.
  
+config INTEL_MFLD_THERMAL
+       tristate "Thermal driver for Intel Medfield platform"
+       depends on INTEL_SCU_IPC && THERMAL
+       help
+         Say Y here to enable thermal driver support for the  Intel Medfield
+         platform.
+
 config RAR_REGISTER
 	bool "Restricted Access Region Register Driver"
 	depends on PCI && X86_MRST
@@ -30,7 +30,8 @@
 obj-$(CONFIG_ACPI_TOSHIBA)	+= toshiba_acpi.o
 obj-$(CONFIG_TOSHIBA_BT_RFKILL)	+= toshiba_bluetooth.o
 obj-$(CONFIG_INTEL_SCU_IPC)	+= intel_scu_ipc.o
-obj-$(CONFIG_INTEL_SCU_IPC_UTIL)+= intel_scu_ipcutil.o
+obj-$(CONFIG_INTEL_SCU_IPC_UTIL) += intel_scu_ipcutil.o
+obj-$(CONFIG_INTEL_MFLD_THERMAL) += intel_mid_thermal.o
 obj-$(CONFIG_RAR_REGISTER)	+= intel_rar_register.o
 obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
 obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
+/*
+ * 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 <asm/intel_scu_ipc.h>
+
+/* Number of thermal sensors */
+#define MSIC_THERMAL_SENSORS   4
+
+/* ADC1 - thermal registers */
+#define MSIC_THERM_ADC1CNTL1   0x1C0
+#define MSIC_ADC_ENBL          0x10
+#define MSIC_ADC_START         0x08
+
+#define MSIC_THERM_ADC1CNTL3   0x1C2
+#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
+#define ADC_CHANLS_MAX         15 /* Number of ADC channels */
+#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    0x1C5   /* increments by 1 */
+#define ADC_DATA_START_ADDR     0x1D4   /* 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, unsigned long *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, unsigned long *temp)
+{
+       struct thermal_device_info *td_info = tzd->devdata;
+       uint16_t adc_val, addr;
+       uint8_t data = 0;
+       int ret;
+       unsigned long curr_temp;
+
+
+       addr = td_info->chnl_addr;
+
+       /* Enable the msic for conversion before reading */
+       ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
+       if (ret)
+               return ret;
+
+       /* Re-toggle the RRDATARD bit (temporary workaround) */
+       ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
+       if (ret)
+               return ret;
+
+       /* Read the higher bits of data */
+       ret = intel_scu_ipc_ioread8(addr, &data);
+       if (ret)
+               return ret;
+
+       /* Shift bits to accomodate the lower two data bits */
+       adc_val = (data << 2);
+       addr++;
+
+       ret = intel_scu_ipc_ioread8(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_scu_ipc_ioread8(MSIC_THERM_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_scu_ipc_iowrite8(MSIC_THERM_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_scu_ipc_iowrite8(base_addr, SKIN_SENSOR0_CODE);
+       if (ret)
+               return ret;
+
+       ret = intel_scu_ipc_iowrite8(base_addr + 1, SKIN_SENSOR1_CODE);
+       if (ret)
+               return ret;
+
+       ret = intel_scu_ipc_iowrite8(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_scu_ipc_iowrite8(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_scu_ipc_ioread8(addr, &data);
+       if (ret)
+               return ret;
+       /* Set the stop bit to zero */
+       return intel_scu_ipc_iowrite8(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_scu_ipc_ioread8(MSIC_THERM_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_scu_ipc_ioread8(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_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL3, &data);
+       if (ret)
+               return ret;
+
+       if (data & MSIC_ADCTHERM_MASK)
+               dev_warn(dev, "ADCTHERM already set");
+
+       /* 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;
+}
+
+/**
+ * mid_thermal_resume - resume routine
+ * @pdev: platform device structure
+ *
+ * mid thermal resume: re-initializes the adc. Can sleep.
+ */
+static int mid_thermal_resume(struct platform_device *pdev)
+{
+       return mid_initialize_adc(&pdev->dev);
+}
+
+/**
+ * mid_thermal_suspend - suspend routine
+ * @pdev: platform device structure
+ *
+ * mid thermal suspend implements the suspend functionality
+ * by stopping the ADC. Can sleep.
+ */
+static int mid_thermal_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+       /*
+        * 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);
+}
+
+/**
+ * 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, unsigned long *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 = kzalloc(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");
+               kfree(pinfo);
+               return ret;
+       }
+
+       /* Register each sensor with the generic thermal framework*/
+       for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
+               pinfo->tzd[i] = thermal_zone_device_register(name[i],
+                                       0, initialize_sensor(i),
+                                       &tzd_ops, 0, 0, 0, 0);
+               if (IS_ERR(pinfo->tzd[i]))
+                       goto reg_fail;
+       }
+
+       pinfo->pdev = pdev;
+       platform_set_drvdata(pdev, pinfo);
+       return 0;
+
+reg_fail:
+       ret = PTR_ERR(pinfo->tzd[i]);
+       while (--i >= 0)
+               thermal_zone_device_unregister(pinfo->tzd[i]);
+       configure_adc(0);
+       kfree(pinfo);
+       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++)
+               thermal_zone_device_unregister(pinfo->tzd[i]);
+
+       platform_set_drvdata(pdev, NULL);
+
+       /* Stop the ADC */
+       return configure_adc(0);
+}
+
+/*********************************************************************
+ *             Driver initialisation and finalization
+ *********************************************************************/
+
+#define DRIVER_NAME "msic_sensor"
+
+static const struct platform_device_id therm_id_table[] = {
+       { DRIVER_NAME, 1 },
+};
+
+static struct platform_driver mid_thermal_driver = {
+       .driver = {
+               .name = DRIVER_NAME,
+               .owner = THIS_MODULE,
+       },
+       .probe = mid_thermal_probe,
+       .suspend = mid_thermal_suspend,
+       .resume = mid_thermal_resume,
+       .remove = __devexit_p(mid_thermal_remove),
+       .id_table = therm_id_table,
+};
+
+static int __init mid_thermal_module_init(void)
+{
+       return platform_driver_register(&mid_thermal_driver);
+}
+
+static void __exit mid_thermal_module_exit(void)
+{
+       platform_driver_unregister(&mid_thermal_driver);
+}
+
+module_init(mid_thermal_module_init);
+module_exit(mid_thermal_module_exit);
+
+MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
+MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
+MODULE_LICENSE("GPL");
...	...	@@ -637,6 +637,13 @@
637	637
638	638	If unsure, say N.
639	639
	640	+config INTEL_MFLD_THERMAL
	641	+ tristate "Thermal driver for Intel Medfield platform"
	642	+ depends on INTEL_SCU_IPC && THERMAL
	643	+ help
	644	+ Say Y here to enable thermal driver support for the Intel Medfield
	645	+ platform.
	646	+
640	647	config RAR_REGISTER
641	648	bool "Restricted Access Region Register Driver"
642	649	depends on PCI && X86_MRST
...	...	@@ -30,7 +30,8 @@
30	30	obj-$(CONFIG_ACPI_TOSHIBA) += toshiba_acpi.o
31	31	obj-$(CONFIG_TOSHIBA_BT_RFKILL) += toshiba_bluetooth.o
32	32	obj-$(CONFIG_INTEL_SCU_IPC) += intel_scu_ipc.o
33		-obj-$(CONFIG_INTEL_SCU_IPC_UTIL)+= intel_scu_ipcutil.o
	33	+obj-$(CONFIG_INTEL_SCU_IPC_UTIL) += intel_scu_ipcutil.o
	34	+obj-$(CONFIG_INTEL_MFLD_THERMAL) += intel_mid_thermal.o
34	35	obj-$(CONFIG_RAR_REGISTER) += intel_rar_register.o
35	36	obj-$(CONFIG_INTEL_IPS) += intel_ips.o
36	37	obj-$(CONFIG_GPIO_INTEL_PMIC) += intel_pmic_gpio.o
	1	+/*
	2	+ * intel_mid_thermal.c - Intel MID platform thermal driver
	3	+ *
	4	+ * Copyright (C) 2011 Intel Corporation
	5	+ *
	6	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	7	+ *
	8	+ * This program is free software; you can redistribute it and/or modify
	9	+ * it under the terms of the GNU General Public License as published by
	10	+ * the Free Software Foundation; version 2 of the License.
	11	+ *
	12	+ * This program is distributed in the hope that it will be useful, but
	13	+ * WITHOUT ANY WARRANTY; without even the implied warranty of
	14	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	+ * General Public License for more details.
	16	+ *
	17	+ * You should have received a copy of the GNU General Public License along
	18	+ * with this program; if not, write to the Free Software Foundation, Inc.,
	19	+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
	20	+ *
	21	+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	22	+ * Author: Durgadoss R <durgadoss.r@intel.com>
	23	+ */
	24	+
	25	+#define pr_fmt(fmt) "intel_mid_thermal: " fmt
	26	+
	27	+#include <linux/module.h>
	28	+#include <linux/init.h>
	29	+#include <linux/err.h>
	30	+#include <linux/param.h>
	31	+#include <linux/device.h>
	32	+#include <linux/platform_device.h>
	33	+#include <linux/slab.h>
	34	+#include <linux/pm.h>
	35	+#include <linux/thermal.h>
	36	+
	37	+#include <asm/intel_scu_ipc.h>
	38	+
	39	+/* Number of thermal sensors */
	40	+#define MSIC_THERMAL_SENSORS 4
	41	+
	42	+/* ADC1 - thermal registers */
	43	+#define MSIC_THERM_ADC1CNTL1 0x1C0
	44	+#define MSIC_ADC_ENBL 0x10
	45	+#define MSIC_ADC_START 0x08
	46	+
	47	+#define MSIC_THERM_ADC1CNTL3 0x1C2
	48	+#define MSIC_ADCTHERM_ENBL 0x04
	49	+#define MSIC_ADCRRDATA_ENBL 0x05
	50	+#define MSIC_CHANL_MASK_VAL 0x0F
	51	+
	52	+#define MSIC_STOPBIT_MASK 16
	53	+#define MSIC_ADCTHERM_MASK 4
	54	+#define ADC_CHANLS_MAX 15 /* Number of ADC channels */
	55	+#define ADC_LOOP_MAX (ADC_CHANLS_MAX - MSIC_THERMAL_SENSORS)
	56	+
	57	+/* ADC channel code values */
	58	+#define SKIN_SENSOR0_CODE 0x08
	59	+#define SKIN_SENSOR1_CODE 0x09
	60	+#define SYS_SENSOR_CODE 0x0A
	61	+#define MSIC_DIE_SENSOR_CODE 0x03
	62	+
	63	+#define SKIN_THERM_SENSOR0 0
	64	+#define SKIN_THERM_SENSOR1 1
	65	+#define SYS_THERM_SENSOR2 2
	66	+#define MSIC_DIE_THERM_SENSOR3 3
	67	+
	68	+/* ADC code range */
	69	+#define ADC_MAX 977
	70	+#define ADC_MIN 162
	71	+#define ADC_VAL0C 887
	72	+#define ADC_VAL20C 720
	73	+#define ADC_VAL40C 508
	74	+#define ADC_VAL60C 315
	75	+
	76	+/* ADC base addresses */
	77	+#define ADC_CHNL_START_ADDR 0x1C5 /* increments by 1 */
	78	+#define ADC_DATA_START_ADDR 0x1D4 /* increments by 2 */
	79	+
	80	+/* MSIC die attributes */
	81	+#define MSIC_DIE_ADC_MIN 488
	82	+#define MSIC_DIE_ADC_MAX 1004
	83	+
	84	+/* This holds the address of the first free ADC channel,
	85	+ * among the 15 channels
	86	+ */
	87	+static int channel_index;
	88	+
	89	+struct platform_info {
	90	+ struct platform_device *pdev;
	91	+ struct thermal_zone_device *tzd[MSIC_THERMAL_SENSORS];
	92	+};
	93	+
	94	+struct thermal_device_info {
	95	+ unsigned int chnl_addr;
	96	+ int direct;
	97	+ /* This holds the current temperature in millidegree celsius */
	98	+ long curr_temp;
	99	+};
	100	+
	101	+/**
	102	+ * to_msic_die_temp - converts adc_val to msic_die temperature
	103	+ * @adc_val: ADC value to be converted
	104	+ *
	105	+ * Can sleep
	106	+ */
	107	+static int to_msic_die_temp(uint16_t adc_val)
	108	+{
	109	+ return (368 * (adc_val) / 1000) - 220;
	110	+}
	111	+
	112	+/**
	113	+ * is_valid_adc - checks whether the adc code is within the defined range
	114	+ * @min: minimum value for the sensor
	115	+ * @max: maximum value for the sensor
	116	+ *
	117	+ * Can sleep
	118	+ */
	119	+static int is_valid_adc(uint16_t adc_val, uint16_t min, uint16_t max)
	120	+{
	121	+ return (adc_val >= min) && (adc_val <= max);
	122	+}
	123	+
	124	+/**
	125	+ * adc_to_temp - converts the ADC code to temperature in C
	126	+ * @direct: true if ths channel is direct index
	127	+ * @adc_val: the adc_val that needs to be converted
	128	+ * @tp: temperature return value
	129	+ *
	130	+ * Linear approximation is used to covert the skin adc value into temperature.
	131	+ * This technique is used to avoid very long look-up table to get
	132	+ * the appropriate temp value from ADC value.
	133	+ * The adc code vs sensor temp curve is split into five parts
	134	+ * to achieve very close approximate temp value with less than
	135	+ * 0.5C error
	136	+ */
	137	+static int adc_to_temp(int direct, uint16_t adc_val, unsigned long *tp)
	138	+{
	139	+ int temp;
	140	+
	141	+ /* Direct conversion for die temperature */
	142	+ if (direct) {
	143	+ if (is_valid_adc(adc_val, MSIC_DIE_ADC_MIN, MSIC_DIE_ADC_MAX)) {
	144	+ tp = to_msic_die_temp(adc_val) 1000;
	145	+ return 0;
	146	+ }
	147	+ return -ERANGE;
	148	+ }
	149	+
	150	+ if (!is_valid_adc(adc_val, ADC_MIN, ADC_MAX))
	151	+ return -ERANGE;
	152	+
	153	+ /* Linear approximation for skin temperature */
	154	+ if (adc_val > ADC_VAL0C)
	155	+ temp = 177 - (adc_val/5);
	156	+ else if ((adc_val <= ADC_VAL0C) && (adc_val > ADC_VAL20C))
	157	+ temp = 111 - (adc_val/8);
	158	+ else if ((adc_val <= ADC_VAL20C) && (adc_val > ADC_VAL40C))
	159	+ temp = 92 - (adc_val/10);
	160	+ else if ((adc_val <= ADC_VAL40C) && (adc_val > ADC_VAL60C))
	161	+ temp = 91 - (adc_val/10);
	162	+ else
	163	+ temp = 112 - (adc_val/6);
	164	+
	165	+ /* Convert temperature in celsius to milli degree celsius */
	166	+ tp = temp 1000;
	167	+ return 0;
	168	+}
	169	+
	170	+/**
	171	+ * mid_read_temp - read sensors for temperature
	172	+ * @temp: holds the current temperature for the sensor after reading
	173	+ *
	174	+ * reads the adc_code from the channel and converts it to real
	175	+ * temperature. The converted value is stored in temp.
	176	+ *
	177	+ * Can sleep
	178	+ */
	179	+static int mid_read_temp(struct thermal_zone_device tzd, unsigned long temp)
	180	+{
	181	+ struct thermal_device_info *td_info = tzd->devdata;
	182	+ uint16_t adc_val, addr;
	183	+ uint8_t data = 0;
	184	+ int ret;
	185	+ unsigned long curr_temp;
	186	+
	187	+
	188	+ addr = td_info->chnl_addr;
	189	+
	190	+ /* Enable the msic for conversion before reading */
	191	+ ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCRRDATA_ENBL);
	192	+ if (ret)
	193	+ return ret;
	194	+
	195	+ /* Re-toggle the RRDATARD bit (temporary workaround) */
	196	+ ret = intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL3, MSIC_ADCTHERM_ENBL);
	197	+ if (ret)
	198	+ return ret;
	199	+
	200	+ /* Read the higher bits of data */
	201	+ ret = intel_scu_ipc_ioread8(addr, &data);
	202	+ if (ret)
	203	+ return ret;
	204	+
	205	+ /* Shift bits to accomodate the lower two data bits */
	206	+ adc_val = (data << 2);
	207	+ addr++;
	208	+
	209	+ ret = intel_scu_ipc_ioread8(addr, &data);/* Read lower bits */
	210	+ if (ret)
	211	+ return ret;
	212	+
	213	+ /* Adding lower two bits to the higher bits */
	214	+ data &= 03;
	215	+ adc_val += data;
	216	+
	217	+ /* Convert ADC value to temperature */
	218	+ ret = adc_to_temp(td_info->direct, adc_val, &curr_temp);
	219	+ if (ret == 0)
	220	+ *temp = td_info->curr_temp = curr_temp;
	221	+ return ret;
	222	+}
	223	+
	224	+/**
	225	+ * configure_adc - enables/disables the ADC for conversion
	226	+ * @val: zero: disables the ADC non-zero:enables the ADC
	227	+ *
	228	+ * Enable/Disable the ADC depending on the argument
	229	+ *
	230	+ * Can sleep
	231	+ */
	232	+static int configure_adc(int val)
	233	+{
	234	+ int ret;
	235	+ uint8_t data;
	236	+
	237	+ ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL1, &data);
	238	+ if (ret)
	239	+ return ret;
	240	+
	241	+ if (val) {
	242	+ /* Enable and start the ADC */
	243	+ data \|= (MSIC_ADC_ENBL \| MSIC_ADC_START);
	244	+ } else {
	245	+ /* Just stop the ADC */
	246	+ data &= (~MSIC_ADC_START);
	247	+ }
	248	+
	249	+ return intel_scu_ipc_iowrite8(MSIC_THERM_ADC1CNTL1, data);
	250	+}
	251	+
	252	+/**
	253	+ * set_up_therm_channel - enable thermal channel for conversion
	254	+ * @base_addr: index of free msic ADC channel
	255	+ *
	256	+ * Enable all the three channels for conversion
	257	+ *
	258	+ * Can sleep
	259	+ */
	260	+static int set_up_therm_channel(u16 base_addr)
	261	+{
	262	+ int ret;
	263	+
	264	+ /* Enable all the sensor channels */
	265	+ ret = intel_scu_ipc_iowrite8(base_addr, SKIN_SENSOR0_CODE);
	266	+ if (ret)
	267	+ return ret;
	268	+
	269	+ ret = intel_scu_ipc_iowrite8(base_addr + 1, SKIN_SENSOR1_CODE);
	270	+ if (ret)
	271	+ return ret;
	272	+
	273	+ ret = intel_scu_ipc_iowrite8(base_addr + 2, SYS_SENSOR_CODE);
	274	+ if (ret)
	275	+ return ret;
	276	+
	277	+ /* Since this is the last channel, set the stop bit
	278	+ to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
	279	+ ret = intel_scu_ipc_iowrite8(base_addr + 3,
	280	+ (MSIC_DIE_SENSOR_CODE \| 0x10));
	281	+ if (ret)
	282	+ return ret;
	283	+
	284	+ /* Enable ADC and start it */
	285	+ return configure_adc(1);
	286	+}
	287	+
	288	+/**
	289	+ * reset_stopbit - sets the stop bit to 0 on the given channel
	290	+ * @addr: address of the channel
	291	+ *
	292	+ * Can sleep
	293	+ */
	294	+static int reset_stopbit(uint16_t addr)
	295	+{
	296	+ int ret;
	297	+ uint8_t data;
	298	+ ret = intel_scu_ipc_ioread8(addr, &data);
	299	+ if (ret)
	300	+ return ret;
	301	+ /* Set the stop bit to zero */
	302	+ return intel_scu_ipc_iowrite8(addr, (data & 0xEF));
	303	+}
	304	+
	305	+/**
	306	+ * find_free_channel - finds an empty channel for conversion
	307	+ *
	308	+ * If the ADC is not enabled then start using 0th channel
	309	+ * itself. Otherwise find an empty channel by looking for a
	310	+ * channel in which the stopbit is set to 1. returns the index
	311	+ * of the first free channel if succeeds or an error code.
	312	+ *
	313	+ * Context: can sleep
	314	+ *
	315	+ * FIXME: Ultimately the channel allocator will move into the intel_scu_ipc
	316	+ * code.
	317	+ */
	318	+static int find_free_channel(void)
	319	+{
	320	+ int ret;
	321	+ int i;
	322	+ uint8_t data;
	323	+
	324	+ /* check whether ADC is enabled */
	325	+ ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL1, &data);
	326	+ if (ret)
	327	+ return ret;
	328	+
	329	+ if ((data & MSIC_ADC_ENBL) == 0)
	330	+ return 0;
	331	+
	332	+ /* ADC is already enabled; Looking for an empty channel */
	333	+ for (i = 0; i < ADC_CHANLS_MAX; i++) {
	334	+ ret = intel_scu_ipc_ioread8(ADC_CHNL_START_ADDR + i, &data);
	335	+ if (ret)
	336	+ return ret;
	337	+
	338	+ if (data & MSIC_STOPBIT_MASK) {
	339	+ ret = i;
	340	+ break;
	341	+ }
	342	+ }
	343	+ return (ret > ADC_LOOP_MAX) ? (-EINVAL) : ret;
	344	+}
	345	+
	346	+/**
	347	+ * mid_initialize_adc - initializing the ADC
	348	+ * @dev: our device structure
	349	+ *
	350	+ * Initialize the ADC for reading thermistor values. Can sleep.
	351	+ */
	352	+static int mid_initialize_adc(struct device *dev)
	353	+{
	354	+ u8 data;
	355	+ u16 base_addr;
	356	+ int ret;
	357	+
	358	+ /*
	359	+ * Ensure that adctherm is disabled before we
	360	+ * initialize the ADC
	361	+ */
	362	+ ret = intel_scu_ipc_ioread8(MSIC_THERM_ADC1CNTL3, &data);
	363	+ if (ret)
	364	+ return ret;
	365	+
	366	+ if (data & MSIC_ADCTHERM_MASK)
	367	+ dev_warn(dev, "ADCTHERM already set");
	368	+
	369	+ /* Index of the first channel in which the stop bit is set */
	370	+ channel_index = find_free_channel();
	371	+ if (channel_index < 0) {
	372	+ dev_err(dev, "No free ADC channels");
	373	+ return channel_index;
	374	+ }
	375	+
	376	+ base_addr = ADC_CHNL_START_ADDR + channel_index;
	377	+
	378	+ if (!(channel_index == 0 \|\| channel_index == ADC_LOOP_MAX)) {
	379	+ /* Reset stop bit for channels other than 0 and 12 */
	380	+ ret = reset_stopbit(base_addr);
	381	+ if (ret)
	382	+ return ret;
	383	+
	384	+ /* Index of the first free channel */
	385	+ base_addr++;
	386	+ channel_index++;
	387	+ }
	388	+
	389	+ ret = set_up_therm_channel(base_addr);
	390	+ if (ret) {
	391	+ dev_err(dev, "unable to enable ADC");
	392	+ return ret;
	393	+ }
	394	+ dev_dbg(dev, "ADC initialization successful");
	395	+ return ret;
	396	+}
	397	+
	398	+/**
	399	+ * initialize_sensor - sets default temp and timer ranges
	400	+ * @index: index of the sensor
	401	+ *
	402	+ * Context: can sleep
	403	+ */
	404	+static struct thermal_device_info *initialize_sensor(int index)
	405	+{
	406	+ struct thermal_device_info *td_info =
	407	+ kzalloc(sizeof(struct thermal_device_info), GFP_KERNEL);
	408	+
	409	+ if (!td_info)
	410	+ return NULL;
	411	+
	412	+ /* Set the base addr of the channel for this sensor */
	413	+ td_info->chnl_addr = ADC_DATA_START_ADDR + 2 * (channel_index + index);
	414	+ /* Sensor 3 is direct conversion */
	415	+ if (index == 3)
	416	+ td_info->direct = 1;
	417	+ return td_info;
	418	+}
	419	+
	420	+/**
	421	+ * mid_thermal_resume - resume routine
	422	+ * @pdev: platform device structure
	423	+ *
	424	+ * mid thermal resume: re-initializes the adc. Can sleep.
	425	+ */
	426	+static int mid_thermal_resume(struct platform_device *pdev)
	427	+{
	428	+ return mid_initialize_adc(&pdev->dev);
	429	+}
	430	+
	431	+/**
	432	+ * mid_thermal_suspend - suspend routine
	433	+ * @pdev: platform device structure
	434	+ *
	435	+ * mid thermal suspend implements the suspend functionality
	436	+ * by stopping the ADC. Can sleep.
	437	+ */
	438	+static int mid_thermal_suspend(struct platform_device *pdev, pm_message_t mesg)
	439	+{
	440	+ /*
	441	+ * This just stops the ADC and does not disable it.
	442	+ * temporary workaround until we have a generic ADC driver.
	443	+ * If 0 is passed, it disables the ADC.
	444	+ */
	445	+ return configure_adc(0);
	446	+}
	447	+
	448	+/**
	449	+ * read_curr_temp - reads the current temperature and stores in temp
	450	+ * @temp: holds the current temperature value after reading
	451	+ *
	452	+ * Can sleep
	453	+ */
	454	+static int read_curr_temp(struct thermal_zone_device tzd, unsigned long temp)
	455	+{
	456	+ WARN_ON(tzd == NULL);
	457	+ return mid_read_temp(tzd, temp);
	458	+}
	459	+
	460	+/* Can't be const */
	461	+static struct thermal_zone_device_ops tzd_ops = {
	462	+ .get_temp = read_curr_temp,
	463	+};
	464	+
	465	+
	466	+/**
	467	+ * mid_thermal_probe - mfld thermal initialize
	468	+ * @pdev: platform device structure
	469	+ *
	470	+ * mid thermal probe initializes the hardware and registers
	471	+ * all the sensors with the generic thermal framework. Can sleep.
	472	+ */
	473	+static int mid_thermal_probe(struct platform_device *pdev)
	474	+{
	475	+ static char *name[MSIC_THERMAL_SENSORS] = {
	476	+ "skin0", "skin1", "sys", "msicdie"
	477	+ };
	478	+
	479	+ int ret;
	480	+ int i;
	481	+ struct platform_info *pinfo;
	482	+
	483	+ pinfo = kzalloc(sizeof(struct platform_info), GFP_KERNEL);
	484	+ if (!pinfo)
	485	+ return -ENOMEM;
	486	+
	487	+ /* Initializing the hardware */
	488	+ ret = mid_initialize_adc(&pdev->dev);
	489	+ if (ret) {
	490	+ dev_err(&pdev->dev, "ADC init failed");
	491	+ kfree(pinfo);
	492	+ return ret;
	493	+ }
	494	+
	495	+ /* Register each sensor with the generic thermal framework*/
	496	+ for (i = 0; i < MSIC_THERMAL_SENSORS; i++) {
	497	+ pinfo->tzd[i] = thermal_zone_device_register(name[i],
	498	+ 0, initialize_sensor(i),
	499	+ &tzd_ops, 0, 0, 0, 0);
	500	+ if (IS_ERR(pinfo->tzd[i]))
	501	+ goto reg_fail;
	502	+ }
	503	+
	504	+ pinfo->pdev = pdev;
	505	+ platform_set_drvdata(pdev, pinfo);
	506	+ return 0;
	507	+
	508	+reg_fail:
	509	+ ret = PTR_ERR(pinfo->tzd[i]);
	510	+ while (--i >= 0)
	511	+ thermal_zone_device_unregister(pinfo->tzd[i]);
	512	+ configure_adc(0);
	513	+ kfree(pinfo);
	514	+ return ret;
	515	+}
	516	+
	517	+/**
	518	+ * mid_thermal_remove - mfld thermal finalize
	519	+ * @dev: platform device structure
	520	+ *
	521	+ * MLFD thermal remove unregisters all the sensors from the generic
	522	+ * thermal framework. Can sleep.
	523	+ */
	524	+static int mid_thermal_remove(struct platform_device *pdev)
	525	+{
	526	+ int i;
	527	+ struct platform_info *pinfo = platform_get_drvdata(pdev);
	528	+
	529	+ for (i = 0; i < MSIC_THERMAL_SENSORS; i++)
	530	+ thermal_zone_device_unregister(pinfo->tzd[i]);
	531	+
	532	+ platform_set_drvdata(pdev, NULL);
	533	+
	534	+ /* Stop the ADC */
	535	+ return configure_adc(0);
	536	+}
	537	+
	538	+/*********************************************************************
	539	+ * Driver initialisation and finalization
	540	+ *********************************************************************/
	541	+
	542	+#define DRIVER_NAME "msic_sensor"
	543	+
	544	+static const struct platform_device_id therm_id_table[] = {
	545	+ { DRIVER_NAME, 1 },
	546	+};
	547	+
	548	+static struct platform_driver mid_thermal_driver = {
	549	+ .driver = {
	550	+ .name = DRIVER_NAME,
	551	+ .owner = THIS_MODULE,
	552	+ },
	553	+ .probe = mid_thermal_probe,
	554	+ .suspend = mid_thermal_suspend,
	555	+ .resume = mid_thermal_resume,
	556	+ .remove = __devexit_p(mid_thermal_remove),
	557	+ .id_table = therm_id_table,
	558	+};
	559	+
	560	+static int __init mid_thermal_module_init(void)
	561	+{
	562	+ return platform_driver_register(&mid_thermal_driver);
	563	+}
	564	+
	565	+static void __exit mid_thermal_module_exit(void)
	566	+{
	567	+ platform_driver_unregister(&mid_thermal_driver);
	568	+}
	569	+
	570	+module_init(mid_thermal_module_init);
	571	+module_exit(mid_thermal_module_exit);
	572	+
	573	+MODULE_AUTHOR("Durgadoss R <durgadoss.r@intel.com>");
	574	+MODULE_DESCRIPTION("Intel Medfield Platform Thermal Driver");
	575	+MODULE_LICENSE("GPL");