diff options
Diffstat (limited to 'drivers/mfd/tps65911-comparator.c')
| -rw-r--r-- | drivers/mfd/tps65911-comparator.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/mfd/tps65911-comparator.c b/drivers/mfd/tps65911-comparator.c new file mode 100644 index 000000000000..3d2dc56a3d40 --- /dev/null +++ b/drivers/mfd/tps65911-comparator.c @@ -0,0 +1,188 @@ +/* + * tps65910.c -- TI TPS6591x + * + * Copyright 2010 Texas Instruments Inc. + * + * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk> + * + * 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; either version 2 of the License, or (at your + * option) any later version. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/debugfs.h> +#include <linux/gpio.h> +#include <linux/mfd/tps65910.h> + +#define COMP 0 +#define COMP1 1 +#define COMP2 2 + +/* Comparator 1 voltage selection table in milivolts */ +static const u16 COMP_VSEL_TABLE[] = { + 0, 2500, 2500, 2500, 2500, 2550, 2600, 2650, + 2700, 2750, 2800, 2850, 2900, 2950, 3000, 3050, + 3100, 3150, 3200, 3250, 3300, 3350, 3400, 3450, + 3500, +}; + +struct comparator { + const char *name; + int reg; + int uV_max; + const u16 *vsel_table; +}; + +static struct comparator tps_comparators[] = { + { + .name = "COMP1", + .reg = TPS65911_VMBCH, + .uV_max = 3500, + .vsel_table = COMP_VSEL_TABLE, + }, + { + .name = "COMP2", + .reg = TPS65911_VMBCH2, + .uV_max = 3500, + .vsel_table = COMP_VSEL_TABLE, + }, +}; + +static int comp_threshold_set(struct tps65910 *tps65910, int id, int voltage) +{ + struct comparator tps_comp = tps_comparators[id]; + int curr_voltage = 0; + int ret; + u8 index = 0, val; + + if (id == COMP) + return 0; + + while (curr_voltage < tps_comp.uV_max) { + curr_voltage = tps_comp.vsel_table[index]; + if (curr_voltage >= voltage) + break; + else if (curr_voltage < voltage) + index ++; + } + + if (curr_voltage > tps_comp.uV_max) + return -EINVAL; + + val = index << 1; + ret = tps65910->write(tps65910, tps_comp.reg, 1, &val); + + return ret; +} + +static int comp_threshold_get(struct tps65910 *tps65910, int id) +{ + struct comparator tps_comp = tps_comparators[id]; + int ret; + u8 val; + + if (id == COMP) + return 0; + + ret = tps65910->read(tps65910, tps_comp.reg, 1, &val); + if (ret < 0) + return ret; + + val >>= 1; + return tps_comp.vsel_table[val]; +} + +static ssize_t comp_threshold_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tps65910 *tps65910 = dev_get_drvdata(dev->parent); + struct attribute comp_attr = attr->attr; + int id, uVolt; + + if (!strcmp(comp_attr.name, "comp1_threshold")) + id = COMP1; + else if (!strcmp(comp_attr.name, "comp2_threshold")) + id = COMP2; + else + return -EINVAL; + + uVolt = comp_threshold_get(tps65910, id); + + return sprintf(buf, "%d\n", uVolt); +} + +static DEVICE_ATTR(comp1_threshold, S_IRUGO, comp_threshold_show, NULL); +static DEVICE_ATTR(comp2_threshold, S_IRUGO, comp_threshold_show, NULL); + +static __devinit int tps65911_comparator_probe(struct platform_device *pdev) +{ + struct tps65910 *tps65910 = dev_get_drvdata(pdev->dev.parent); + struct tps65910_platform_data *pdata = dev_get_platdata(tps65910->dev); + int ret; + + ret = comp_threshold_set(tps65910, COMP1, pdata->vmbch_threshold); + if (ret < 0) { + dev_err(&pdev->dev, "cannot set COMP1 threshold\n"); + return ret; + } + + ret = comp_threshold_set(tps65910, COMP2, pdata->vmbch2_threshold); + if (ret < 0) { + dev_err(&pdev->dev, "cannot set COMP2 theshold\n"); + return ret; + } + + /* Create sysfs entry */ + ret = device_create_file(&pdev->dev, &dev_attr_comp1_threshold); + if (ret < 0) + dev_err(&pdev->dev, "failed to add COMP1 sysfs file\n"); + + ret = device_create_file(&pdev->dev, &dev_attr_comp2_threshold); + if (ret < 0) + dev_err(&pdev->dev, "failed to add COMP2 sysfs file\n"); + + return ret; +} + +static __devexit int tps65911_comparator_remove(struct platform_device *pdev) +{ + struct tps65910 *tps65910; + + tps65910 = dev_get_drvdata(pdev->dev.parent); + + return 0; +} + +static struct platform_driver tps65911_comparator_driver = { + .driver = { + .name = "tps65911-comparator", + .owner = THIS_MODULE, + }, + .probe = tps65911_comparator_probe, + .remove = __devexit_p(tps65911_comparator_remove), +}; + +static int __init tps65911_comparator_init(void) +{ + return platform_driver_register(&tps65911_comparator_driver); +} +subsys_initcall(tps65911_comparator_init); + +static void __exit tps65911_comparator_exit(void) +{ + platform_driver_unregister(&tps65911_comparator_driver); +} +module_exit(tps65911_comparator_exit); + +MODULE_AUTHOR("Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>"); +MODULE_DESCRIPTION("TPS65911 comparator driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:tps65911-comparator"); |