/* * tsc210x_sensors.c - hwmon interface to TI TSC210x sensors * * Copyright (c) 2005-2007 Andrzej Zaborowski * * This package 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 package 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 package; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include #include #ifdef CONFIG_APM # include #endif #include /* * TI TSC210x chips include an ADC that's shared between various * sensors (temperature, battery, vAUX, etc) and the touchscreen. * This driver packages access to the non-touchscreen sensors * available on a given board. */ struct tsc210x_hwmon { int bat[2], aux[2], temp[2]; struct device *dev; struct tsc210x_config *pdata; #ifdef CONFIG_APM /* prevent APM from colliding with normal hwmon accessors */ spinlock_t apm_lock; #endif }; #ifdef CONFIG_APM # define apm_lock(h) spin_lock(&(h)->apm_lock) # define apm_unlock(h) spin_unlock(&(h)->apm_lock) #else # define apm_lock(h) do { } while (0) # define apm_unlock(h) do { } while (0) #endif static void tsc210x_ports(void *context, int bat[], int aux[]) { struct tsc210x_hwmon *hwmon = context; apm_lock(hwmon); /* FIXME for tsc2101 and tsc2111, battery voltage is: * VBAT = (5 * VREF * (bat[x])) / (2 ^ bits) * For tsc2100 and tsc2102, use "6" not "5"; that formula ignores * an external 100-300 Ohm resistor making the right value be just * a bit over 5 (or 6). * * FIXME the vAUX measurements need scaling too, but in that case * there's no *internal* voltage divider so just scale to VREF. * * --> This code needs to know VREF, the VBAT multiplier, and * the precision. For now, assume VREF 1.25V and 12 bits. * When an external reference is used, it normally won't * match the 1.25V (or 2.5V) values supported internally... * * --> Output units should become milliVolts; currently they are * dimensionless... */ hwmon->bat[0] = bat[0]; hwmon->bat[1] = bat[1]; hwmon->aux[0] = aux[0]; hwmon->aux[1] = aux[1]; apm_unlock(hwmon); } /* FIXME temp sensors also need scaling so values are milliVolts... * temperature (given calibration data) should be millidegrees C. */ static void tsc210x_temp1(void *context, int temp) { struct tsc210x_hwmon *hwmon = context; apm_lock(hwmon); hwmon->temp[0] = temp; apm_unlock(hwmon); } static void tsc210x_temp2(void *context, int temp) { struct tsc210x_hwmon *hwmon = context; apm_lock(hwmon); hwmon->temp[1] = temp; apm_unlock(hwmon); } #define TSC210X_INPUT(devname, field) \ static ssize_t tsc_show_ ## devname(struct device *dev, \ struct device_attribute *devattr, char *buf) \ { \ struct tsc210x_hwmon *hwmon = dev_get_drvdata(dev); \ return sprintf(buf, "%i\n", hwmon->field); \ } \ static DEVICE_ATTR(devname ## _input, S_IRUGO, tsc_show_ ## devname, NULL); TSC210X_INPUT(in0, bat[0]) TSC210X_INPUT(in1, bat[1]) TSC210X_INPUT(in2, aux[0]) TSC210X_INPUT(in3, aux[1]) TSC210X_INPUT(in4, temp[0]) TSC210X_INPUT(in5, temp[1]) static ssize_t tsc_show_temp1(struct device *dev, struct device_attribute *devattr, char *buf) { struct tsc210x_hwmon *hwmon = dev_get_drvdata(dev); int t1 = hwmon->temp[0]; int t2 = hwmon->temp[1]; int diff; int value; /* * Use method #2 (differential) to calculate current temperature. * The difference between TEMP2 and TEMP1 input values is * multiplied by a constant to obtain current temperature. * To find this constant we use the values measured at 25 C as * thermometer calibration data. * * 298150 is 25 degrees Celcius represented in Kelvins and * multiplied by 1000 for fixed point precision (273.15 + 25). * 273150 is zero degrees Celcius. */ diff = hwmon->pdata->temp_at25c[1] - hwmon->pdata->temp_at25c[0]; value = (t2 - t1) * 298150 / diff; /* This is in Kelvins now */ value -= 273150; /* Celcius millidegree */ return sprintf(buf, "%i\n", value); } static DEVICE_ATTR(temp1_input, S_IRUGO, tsc_show_temp1, NULL); #ifdef CONFIG_APM static struct tsc210x_hwmon *apm_hwmon; static void tsc210x_get_power_status(struct apm_power_info *info) { struct tsc210x_hwmon *hwmon = apm_hwmon; apm_lock(hwmon); hwmon->pdata->apm_report(info, hwmon->bat); apm_unlock(hwmon); } #endif static int tsc210x_hwmon_probe(struct platform_device *pdev) { struct tsc210x_hwmon *hwmon; struct tsc210x_config *pdata = pdev->dev.platform_data; int status = 0; hwmon = (struct tsc210x_hwmon *) kzalloc(sizeof(struct tsc210x_hwmon), GFP_KERNEL); if (!hwmon) { dev_dbg(&pdev->dev, "allocation failed\n"); return -ENOMEM; } hwmon->dev = hwmon_device_register(&pdev->dev); if (IS_ERR(hwmon->dev)) { kfree(hwmon); dev_dbg(&pdev->dev, "registration failed\n"); return PTR_ERR(hwmon->dev); } hwmon->pdata = pdata; #ifdef CONFIG_APM spin_lock_init(&hwmon->apm_lock); if (pdata->apm_report) { apm_hwmon = hwmon; apm_get_power_status = tsc210x_get_power_status; } #endif platform_set_drvdata(pdev, hwmon); if (pdata->monitor & (TSC_BAT1 | TSC_BAT2 | TSC_AUX1 | TSC_AUX2)) status |= tsc210x_ports_cb(pdev->dev.parent, tsc210x_ports, hwmon); if (pdata->monitor & TSC_TEMP) { status |= tsc210x_temp1_cb(pdev->dev.parent, tsc210x_temp1, hwmon); status |= tsc210x_temp2_cb(pdev->dev.parent, tsc210x_temp2, hwmon); } if (status) { tsc210x_ports_cb(pdev->dev.parent, NULL, NULL); tsc210x_temp1_cb(pdev->dev.parent, NULL, NULL); tsc210x_temp2_cb(pdev->dev.parent, NULL, NULL); platform_set_drvdata(pdev, NULL); #ifdef CONFIG_APM if (pdata->apm_report) apm_get_power_status = 0; #endif hwmon_device_unregister(hwmon->dev); kfree(hwmon); return status; } if (pdata->monitor & TSC_BAT1) status |= device_create_file(&pdev->dev, &dev_attr_in0_input); if (pdata->monitor & TSC_BAT2) status |= device_create_file(&pdev->dev, &dev_attr_in1_input); if (pdata->monitor & TSC_AUX1) status |= device_create_file(&pdev->dev, &dev_attr_in2_input); if (pdata->monitor & TSC_AUX2) status |= device_create_file(&pdev->dev, &dev_attr_in3_input); if (pdata->monitor & TSC_TEMP) { status |= device_create_file(&pdev->dev, &dev_attr_in4_input); status |= device_create_file(&pdev->dev, &dev_attr_in5_input); if ((pdata->temp_at25c[1] - pdata->temp_at25c[0]) == 0) dev_warn(&pdev->dev, "No temp calibration data.\n"); else status |= device_create_file(&pdev->dev, &dev_attr_temp1_input); } if (status) /* Not fatal */ dev_dbg(&pdev->dev, "Creating one or more " "attribute files failed\n"); return 0; } static int __exit tsc210x_hwmon_remove(struct platform_device *pdev) { struct tsc210x_hwmon *dev = platform_get_drvdata(pdev); tsc210x_ports_cb(pdev->dev.parent, NULL, NULL); tsc210x_temp1_cb(pdev->dev.parent, NULL, NULL); tsc210x_temp2_cb(pdev->dev.parent, NULL, NULL); platform_set_drvdata(pdev, NULL); #ifdef CONFIG_APM if (dev->pdata->apm_report) apm_get_power_status = 0; #endif hwmon_device_unregister(dev->dev); kfree(dev); return 0; } static struct platform_driver tsc210x_hwmon_driver = { .probe = tsc210x_hwmon_probe, .remove = __exit_p(tsc210x_hwmon_remove), /* Nothing to do on suspend/resume */ .driver = { .name = "tsc210x-hwmon", }, }; static int __init tsc210x_hwmon_init(void) { /* can't use driver_probe() here since the parent device * gets registered "late" */ return platform_driver_register(&tsc210x_hwmon_driver); } module_init(tsc210x_hwmon_init); static void __exit tsc210x_hwmon_exit(void) { platform_driver_unregister(&tsc210x_hwmon_driver); } module_exit(tsc210x_hwmon_exit); MODULE_AUTHOR("Andrzej Zaborowski"); MODULE_DESCRIPTION("hwmon driver for TI TSC210x-connected sensors."); MODULE_LICENSE("GPL");