/* * ad525x_dpot: Driver for the Analog Devices digital potentiometers * Copyright (c) 2009-2010 Analog Devices, Inc. * Author: Michael Hennerich * * DEVID #Wipers #Positions Resistor Options (kOhm) * AD5258 1 64 1, 10, 50, 100 * AD5259 1 256 5, 10, 50, 100 * AD5251 2 64 1, 10, 50, 100 * AD5252 2 256 1, 10, 50, 100 * AD5255 3 512 25, 250 * AD5253 4 64 1, 10, 50, 100 * AD5254 4 256 1, 10, 50, 100 * AD5160 1 256 5, 10, 50, 100 * AD5161 1 256 5, 10, 50, 100 * AD5162 2 256 2.5, 10, 50, 100 * AD5165 1 256 100 * AD5200 1 256 10, 50 * AD5201 1 33 10, 50 * AD5203 4 64 10, 100 * AD5204 4 256 10, 50, 100 * AD5206 6 256 10, 50, 100 * AD5207 2 256 10, 50, 100 * AD5231 1 1024 10, 50, 100 * AD5232 2 256 10, 50, 100 * AD5233 4 64 10, 50, 100 * AD5235 2 1024 25, 250 * AD5260 1 256 20, 50, 200 * AD5262 2 256 20, 50, 200 * AD5263 4 256 20, 50, 200 * AD5290 1 256 10, 50, 100 * AD5291 1 256 20 * AD5292 1 1024 20 * AD5293 1 1024 20 * AD7376 1 128 10, 50, 100, 1M * AD8400 1 256 1, 10, 50, 100 * AD8402 2 256 1, 10, 50, 100 * AD8403 4 256 1, 10, 50, 100 * ADN2850 3 512 25, 250 * * See Documentation/misc-devices/ad525x_dpot.txt for more info. * * derived from ad5258.c * Copyright (c) 2009 Cyber Switching, Inc. * Author: Chris Verges * * derived from ad5252.c * Copyright (c) 2006 Michael Hennerich * * Licensed under the GPL-2 or later. */ #include #include #include #include #include #include #define DRIVER_VERSION "0.2" #include "ad525x_dpot.h" /* * Client data (each client gets its own) */ struct dpot_data { struct ad_dpot_bus_data bdata; struct mutex update_lock; unsigned rdac_mask; unsigned max_pos; unsigned long devid; unsigned uid; unsigned feat; unsigned wipers; u16 rdac_cache[8]; }; static inline int dpot_read_d8(struct dpot_data *dpot) { return dpot->bdata.bops->read_d8(dpot->bdata.client); } static inline int dpot_read_r8d8(struct dpot_data *dpot, u8 reg) { return dpot->bdata.bops->read_r8d8(dpot->bdata.client, reg); } static inline int dpot_read_r8d16(struct dpot_data *dpot, u8 reg) { return dpot->bdata.bops->read_r8d16(dpot->bdata.client, reg); } static inline int dpot_write_d8(struct dpot_data *dpot, u8 val) { return dpot->bdata.bops->write_d8(dpot->bdata.client, val); } static inline int dpot_write_r8d8(struct dpot_data *dpot, u8 reg, u16 val) { return dpot->bdata.bops->write_r8d8(dpot->bdata.client, reg, val); } static inline int dpot_write_r8d16(struct dpot_data *dpot, u8 reg, u16 val) { return dpot->bdata.bops->write_r8d16(dpot->bdata.client, reg, val); } static s32 dpot_read(struct dpot_data *dpot, u8 reg) { unsigned val = 0; if (dpot->feat & F_SPI) { if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) { if (dpot->feat & F_RDACS_WONLY) return dpot->rdac_cache[reg & DPOT_RDAC_MASK]; if (dpot->uid == DPOT_UID(AD5291_ID) || dpot->uid == DPOT_UID(AD5292_ID) || dpot->uid == DPOT_UID(AD5293_ID)) return dpot_read_r8d8(dpot, DPOT_AD5291_READ_RDAC << 2); val = DPOT_SPI_READ_RDAC; } else if (reg & DPOT_ADDR_EEPROM) { val = DPOT_SPI_READ_EEPROM; } if (dpot->feat & F_SPI_16BIT) return dpot_read_r8d8(dpot, val); else if (dpot->feat & F_SPI_24BIT) return dpot_read_r8d16(dpot, val); } else { /* I2C */ if ((reg & DPOT_REG_TOL) || (dpot->max_pos > 256)) return dpot_read_r8d16(dpot, (reg & 0xF8) | ((reg & 0x7) << 1)); else return dpot_read_r8d8(dpot, reg); } return -EFAULT; } static s32 dpot_write(struct dpot_data *dpot, u8 reg, u16 value) { unsigned val = 0; if (dpot->feat & F_SPI) { if (!(reg & (DPOT_ADDR_EEPROM | DPOT_ADDR_CMD))) { if (dpot->feat & F_RDACS_WONLY) dpot->rdac_cache[reg & DPOT_RDAC_MASK] = value; if (dpot->feat & F_AD_APPDATA) { if (dpot->feat & F_SPI_8BIT) { val = ((reg & DPOT_RDAC_MASK) << DPOT_MAX_POS(dpot->devid)) | value; return dpot_write_d8(dpot, val); } else if (dpot->feat & F_SPI_16BIT) { val = ((reg & DPOT_RDAC_MASK) << DPOT_MAX_POS(dpot->devid)) | value; return dpot_write_r8d8(dpot, val >> 8, val & 0xFF); } else BUG(); } else { if (dpot->uid == DPOT_UID(AD5291_ID) || dpot->uid == DPOT_UID(AD5292_ID) || dpot->uid == DPOT_UID(AD5293_ID)) return dpot_write_r8d8(dpot, (DPOT_AD5291_RDAC << 2) | (value >> 8), value & 0xFF); val = DPOT_SPI_RDAC | (reg & DPOT_RDAC_MASK); } } else if (reg & DPOT_ADDR_EEPROM) { val = DPOT_SPI_EEPROM | (reg & DPOT_RDAC_MASK); } else if (reg & DPOT_ADDR_CMD) { switch (reg) { case DPOT_DEC_ALL_6DB: val = DPOT_SPI_DEC_ALL_6DB; break; case DPOT_INC_ALL_6DB: val = DPOT_SPI_INC_ALL_6DB; break; case DPOT_DEC_ALL: val = DPOT_SPI_DEC_ALL; break; case DPOT_INC_ALL: val = DPOT_SPI_INC_ALL; break; } } else BUG(); if (dpot->feat & F_SPI_16BIT) return dpot_write_r8d8(dpot, val, value); else if (dpot->feat & F_SPI_24BIT) return dpot_write_r8d16(dpot, val, value); } else { /* Only write the instruction byte for certain commands */ if (reg & DPOT_ADDR_CMD) return dpot_write_d8(dpot, reg); if (dpot->max_pos > 256) return dpot_write_r8d16(dpot, (reg & 0xF8) | ((reg & 0x7) << 1), value); else /* All other registers require instruction + data bytes */ return dpot_write_r8d8(dpot, reg, value); } return -EFAULT; } /* sysfs functions */ static ssize_t sysfs_show_reg(struct device *dev, struct device_attribute *attr, char *buf, u32 reg) { struct dpot_data *data = dev_get_drvdata(dev); s32 value; mutex_lock(&data->update_lock); value = dpot_read(data, reg); mutex_unlock(&data->update_lock); if (value < 0) return -EINVAL; /* * Let someone else deal with converting this ... * the tolerance is a two-byte value where the MSB * is a sign + integer value, and the LSB is a * decimal value. See page 18 of the AD5258 * datasheet (Rev. A) for more details. */ if (reg & DPOT_REG_TOL) return sprintf(buf, "0x%04x\n", value & 0xFFFF); else return sprintf(buf, "%u\n", value & data->rdac_mask); } static ssize_t sysfs_set_reg(struct device *dev, struct device_attribute *attr, const char *buf, size_t count, u32 reg) { struct dpot_data *data = dev_get_drvdata(dev); unsigned long value; int err; err = strict_strtoul(buf, 10, &value); if (err) return err; if (value > data->rdac_mask) value = data->rdac_mask; mutex_lock(&data->update_lock); dpot_write(data, reg, value); if (reg & DPOT_ADDR_EEPROM) msleep(26); /* Sleep while the EEPROM updates */ mutex_unlock(&data->update_lock); return count; } static ssize_t sysfs_do_cmd(struct device *dev, struct device_attribute *attr, const char *buf, size_t count, u32 reg) { struct dpot_data *data = dev_get_drvdata(dev); mutex_lock(&data->update_lock); dpot_write(data, reg, 0); mutex_unlock(&data->update_lock); return count; } /* ------------------------------------------------------------------------- */ #define DPOT_DEVICE_SHOW(_name, _reg) static ssize_t \ show_##_name(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ return sysfs_show_reg(dev, attr, buf, _reg); \ } #define DPOT_DEVICE_SET(_name, _reg) static ssize_t \ set_##_name(struct device *dev, \ struct device_attribute *attr, \ const char *buf, size_t count) \ { \ return sysfs_set_reg(dev, attr, buf, count, _reg); \ } #define DPOT_DEVICE_SHOW_SET(name, reg) \ DPOT_DEVICE_SHOW(name, reg) \ DPOT_DEVICE_SET(name, reg) \ static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, set_##name); #define DPOT_DEVICE_SHOW_ONLY(name, reg) \ DPOT_DEVICE_SHOW(name, reg) \ static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, show_##name, NULL); DPOT_DEVICE_SHOW_SET(rdac0, DPOT_ADDR_RDAC | DPOT_RDAC0); DPOT_DEVICE_SHOW_SET(eeprom0, DPOT_ADDR_EEPROM | DPOT_RDAC0); DPOT_DEVICE_SHOW_ONLY(tolerance0, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC0); DPOT_DEVICE_SHOW_SET(rdac1, DPOT_ADDR_RDAC | DPOT_RDAC1); DPOT_DEVICE_SHOW_SET(eeprom1, DPOT_ADDR_EEPROM | DPOT_RDAC1); DPOT_DEVICE_SHOW_ONLY(tolerance1, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC1); DPOT_DEVICE_SHOW_SET(rdac2, DPOT_ADDR_RDAC | DPOT_RDAC2); DPOT_DEVICE_SHOW_SET(eeprom2, DPOT_ADDR_EEPROM | DPOT_RDAC2); DPOT_DEVICE_SHOW_ONLY(tolerance2, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC2); DPOT_DEVICE_SHOW_SET(rdac3, DPOT_ADDR_RDAC | DPOT_RDAC3); DPOT_DEVICE_SHOW_SET(eeprom3, DPOT_ADDR_EEPROM | DPOT_RDAC3); DPOT_DEVICE_SHOW_ONLY(tolerance3, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC3); DPOT_DEVICE_SHOW_SET(rdac4, DPOT_ADDR_RDAC | DPOT_RDAC4); DPOT_DEVICE_SHOW_SET(eeprom4, DPOT_ADDR_EEPROM | DPOT_RDAC4); DPOT_DEVICE_SHOW_ONLY(tolerance4, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC4); DPOT_DEVICE_SHOW_SET(rdac5, DPOT_ADDR_RDAC | DPOT_RDAC5); DPOT_DEVICE_SHOW_SET(eeprom5, DPOT_ADDR_EEPROM | DPOT_RDAC5); DPOT_DEVICE_SHOW_ONLY(tolerance5, DPOT_ADDR_EEPROM | DPOT_TOL_RDAC5); static const struct attribute *dpot_attrib_wipers[] = { &dev_attr_rdac0.attr, &dev_attr_rdac1.attr, &dev_attr_rdac2.attr, &dev_attr_rdac3.attr, &dev_attr_rdac4.attr, &dev_attr_rdac5.attr, NULL }; static const struct attribute *dpot_attrib_eeprom[] = { &dev_attr_eeprom0.attr, &dev_attr_eeprom1.attr, &dev_attr_eeprom2.attr, &dev_attr_eeprom3.attr, &dev_attr_eeprom4.attr, &dev_attr_eeprom5.attr, NULL }; static const struct attribute *dpot_attrib_tolerance[] = { &dev_attr_tolerance0.attr, &dev_attr_tolerance1.attr, &dev_attr_tolerance2.attr, &dev_attr_tolerance3.attr, &dev_attr_tolerance4.attr, &dev_attr_tolerance5.attr, NULL }; /* ------------------------------------------------------------------------- */ #define DPOT_DEVICE_DO_CMD(_name, _cmd) static ssize_t \ set_##_name(struct device *dev, \ struct device_attribute *attr, \ const char *buf, size_t count) \ { \ return sysfs_do_cmd(dev, attr, buf, count, _cmd); \ } \ static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, NULL, set_##_name); DPOT_DEVICE_DO_CMD(inc_all, DPOT_INC_ALL); DPOT_DEVICE_DO_CMD(dec_all, DPOT_DEC_ALL); DPOT_DEVICE_DO_CMD(inc_all_6db, DPOT_INC_ALL_6DB); DPOT_DEVICE_DO_CMD(dec_all_6db, DPOT_DEC_ALL_6DB); static struct attribute *ad525x_attributes_commands[] = { &dev_attr_inc_all.attr, &dev_attr_dec_all.attr, &dev_attr_inc_all_6db.attr, &dev_attr_dec_all_6db.attr, NULL }; static const struct attribute_group ad525x_group_commands = { .attrs = ad525x_attributes_commands, }; __devinit int ad_dpot_add_files(struct device *dev, unsigned features, unsigned rdac) { int err = sysfs_create_file(&dev->kobj, dpot_attrib_wipers[rdac]); if (features & F_CMD_EEP) err |= sysfs_create_file(&dev->kobj, dpot_attrib_eeprom[rdac]); if (features & F_CMD_TOL) err |= sysfs_create_file(&dev->kobj, dpot_attrib_tolerance[rdac]); if (err) dev_err(dev, "failed to register sysfs hooks for RDAC%d\n", rdac); return err; } inline void ad_dpot_remove_files(struct device *dev, unsigned features, unsigned rdac) { sysfs_remove_file(&dev->kobj, dpot_attrib_wipers[rdac]); if (features & F_CMD_EEP) sysfs_remove_file(&dev->kobj, dpot_attrib_eeprom[rdac]); if (features & F_CMD_TOL) sysfs_remove_file(&dev->kobj, dpot_attrib_tolerance[rdac]); } __devinit int ad_dpot_probe(struct device *dev, struct ad_dpot_bus_data *bdata, const struct ad_dpot_id *id) { struct dpot_data *data; int i, err = 0; data = kzalloc(sizeof(struct dpot_data), GFP_KERNEL); if (!data) { err = -ENOMEM; goto exit; } dev_set_drvdata(dev, data); mutex_init(&data->update_lock); data->bdata = *bdata; data->devid = id->devid; data->max_pos = 1 << DPOT_MAX_POS(data->devid); data->rdac_mask = data->max_pos - 1; data->feat = DPOT_FEAT(data->devid); data->uid = DPOT_UID(data->devid); data->wipers = DPOT_WIPERS(data->devid); for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++) if (data->wipers & (1 << i)) { err = ad_dpot_add_files(dev, data->feat, i); if (err) goto exit_remove_files; /* power-up midscale */ if (data->feat & F_RDACS_WONLY) data->rdac_cache[i] = data->max_pos / 2; } if (data->feat & F_CMD_INC) err = sysfs_create_group(&dev->kobj, &ad525x_group_commands); if (err) { dev_err(dev, "failed to register sysfs hooks\n"); goto exit_free; } dev_info(dev, "%s %d-Position Digital Potentiometer registered\n", id->name, data->max_pos); return 0; exit_remove_files: for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++) if (data->wipers & (1 << i)) ad_dpot_remove_files(dev, data->feat, i); exit_free: kfree(data); dev_set_drvdata(dev, NULL); exit: dev_err(dev, "failed to create client for %s ID 0x%lX\n", id->name, id->devid); return err; } EXPORT_SYMBOL(ad_dpot_probe); __devexit int ad_dpot_remove(struct device *dev) { struct dpot_data *data = dev_get_drvdata(dev); int i; for (i = DPOT_RDAC0; i <= DPOT_RDAC5; i++) if (data->wipers & (1 << i)) ad_dpot_remove_files(dev, data->feat, i); kfree(data); return 0; } EXPORT_SYMBOL(ad_dpot_remove); MODULE_AUTHOR("Chris Verges , " "Michael Hennerich "); MODULE_DESCRIPTION("Digital potentiometer driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRIVER_VERSION);