| /* |
| * 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 accommodate 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"); |