--- /dev/null
+/*
+ * tsc210x_sensors.c - hwmon interface to TI TSC210x sensors
+ *
+ * Copyright (c) 2005-2007 Andrzej Zaborowski <balrog@zabor.org>
+ *
+ * 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 <linux/init.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/autoconf.h>
+#ifdef CONFIG_APM
+# include <linux/apm-emulation.h>
+#endif
+
+#include <linux/spi/tsc210x.h>
+
+
+/*
+ * 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");
projects / linux-2.6-omap-h63xx.git / blobdiff