diff options
Diffstat (limited to 'drivers/platform/x86/intel_mid_thermal.c')
| -rw-r--r-- | drivers/platform/x86/intel_mid_thermal.c | 576 |
1 files changed, 576 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 000000000000..6c12db503161 --- /dev/null +++ b/drivers/platform/x86/intel_mid_thermal.c @@ -0,0 +1,576 @@ +/* + * 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"); |