diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/staging/iio/resolver/ad2s1210.c | 872 |
1 files changed, 872 insertions, 0 deletions
diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c new file mode 100644 index 000000000000..c12f64cc40df --- /dev/null +++ b/drivers/staging/iio/resolver/ad2s1210.c @@ -0,0 +1,872 @@ +/* + * ad2s1210.c support for the ADI Resolver to Digital Converters: AD2S1210 + * + * Copyright (c) 2010-2010 Analog Devices Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/device.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/delay.h> +#include <linux/gpio.h> + +#include "../iio.h" +#include "../sysfs.h" + +#define DRV_NAME "ad2s1210" + +#define DEF_CONTROL 0x7E + +#define MSB_IS_HIGH 0x80 +#define MSB_IS_LOW 0x7F +#define PHASE_LOCK_RANGE_44 0x20 +#define ENABLE_HYSTERESIS 0x10 +#define SET_ENRES1 0x08 +#define SET_ENRES0 0x04 +#define SET_RES1 0x02 +#define SET_RES0 0x01 + +#define SET_ENRESOLUTION (SET_ENRES1 | SET_ENRES0) +#define SET_RESOLUTION (SET_RES1 | SET_RES0) + +#define REG_POSITION 0x80 +#define REG_VELOCITY 0x82 +#define REG_LOS_THRD 0x88 +#define REG_DOS_OVR_THRD 0x89 +#define REG_DOS_MIS_THRD 0x8A +#define REG_DOS_RST_MAX_THRD 0x8B +#define REG_DOS_RST_MIN_THRD 0x8C +#define REG_LOT_HIGH_THRD 0x8D +#define REG_LOT_LOW_THRD 0x8E +#define REG_EXCIT_FREQ 0x91 +#define REG_CONTROL 0x92 +#define REG_SOFT_RESET 0xF0 +#define REG_FAULT 0xFF + +/* pin SAMPLE, A0, A1, RES0, RES1, is controlled by driver */ +#define AD2S1210_SAA 3 +#if defined(CONFIG_AD2S1210_GPIO_INPUT) || defined(CONFIG_AD2S1210_GPIO_OUTPUT) +# define AD2S1210_RES 2 +#else +# define AD2S1210_RES 0 +#endif +#define AD2S1210_PN (AD2S1210_SAA + AD2S1210_RES) + +#define AD2S1210_MIN_CLKIN 6144000 +#define AD2S1210_MAX_CLKIN 10240000 +#define AD2S1210_MIN_EXCIT 2000 +#define AD2S1210_MAX_EXCIT 20000 +#define AD2S1210_MIN_FCW 0x4 +#define AD2S1210_MAX_FCW 0x50 + +/* default input clock on serial interface */ +#define AD2S1210_DEF_CLKIN 8192000 +/* clock period in nano second */ +#define AD2S1210_DEF_TCK (1000000000/AD2S1210_DEF_CLKIN) +#define AD2S1210_DEF_EXCIT 10000 + +enum ad2s1210_mode { + MOD_POS = 0, + MOD_VEL, + MOD_RESERVED, + MOD_CONFIG, +}; + +enum ad2s1210_res { + RES_10 = 10, + RES_12 = 12, + RES_14 = 14, + RES_16 = 16, +}; + +static unsigned int resolution_value[] = { + RES_10, RES_12, RES_14, RES_16}; + +struct ad2s1210_state { + struct mutex lock; + struct iio_dev *idev; + struct spi_device *sdev; + struct spi_transfer xfer; + unsigned int hysteresis; + unsigned int old_data; + enum ad2s1210_mode mode; + enum ad2s1210_res resolution; + unsigned int fclkin; + unsigned int fexcit; + unsigned short sample; + unsigned short a0; + unsigned short a1; + unsigned short res0; + unsigned short res1; + u8 rx[3]; + u8 tx[3]; +}; + +static inline void start_sample(struct ad2s1210_state *st) +{ + gpio_set_value(st->sample, 0); +} + +static inline void stop_sample(struct ad2s1210_state *st) +{ + gpio_set_value(st->sample, 1); +} + +static inline void set_mode(enum ad2s1210_mode mode, struct ad2s1210_state *st) +{ + switch (mode) { + case MOD_POS: + gpio_set_value(st->a0, 0); + gpio_set_value(st->a1, 0); + break; + case MOD_VEL: + gpio_set_value(st->a0, 0); + gpio_set_value(st->a1, 1); + break; + case MOD_CONFIG: + gpio_set_value(st->a0, 1); + gpio_set_value(st->a1, 1); + break; + default: + /* set to reserved mode */ + gpio_set_value(st->a0, 1); + gpio_set_value(st->a1, 0); + } + st->mode = mode; +} + +/* write 1 bytes (address or data) to the chip */ +static int config_write(struct ad2s1210_state *st, + unsigned char data) +{ + struct spi_message msg; + int ret = 0; + + st->xfer.len = 1; + set_mode(MOD_CONFIG, st); + + spi_message_init(&msg); + spi_message_add_tail(&st->xfer, &msg); + st->tx[0] = data; + ret = spi_sync(st->sdev, &msg); + if (ret) + return ret; + st->old_data = 1; + return ret; +} + +/* read value from one of the registers */ +static int config_read(struct ad2s1210_state *st, + unsigned char address, + unsigned char *data) +{ + struct spi_message msg; + int ret = 0; + + st->xfer.len = 2; + set_mode(MOD_CONFIG, st); + + spi_message_init(&msg); + spi_message_add_tail(&st->xfer, &msg); + st->tx[0] = address | MSB_IS_HIGH; + st->tx[1] = REG_FAULT; + ret = spi_sync(st->sdev, &msg); + if (ret) + return ret; + *data = st->rx[1]; + st->old_data = 1; + return ret; +} + +static inline void update_frequency_control_word(struct ad2s1210_state *st) +{ + unsigned char fcw; + fcw = (unsigned char)(st->fexcit * (1 << 15) / st->fclkin); + if (fcw >= AD2S1210_MIN_FCW && fcw <= AD2S1210_MAX_FCW) { + config_write(st, REG_EXCIT_FREQ); + config_write(st, fcw); + } else + pr_err("ad2s1210: FCW out of range\n"); +} + +#if defined(CONFIG_AD2S1210_GPIO_INPUT) +static inline unsigned char read_resolution_pin(struct ad2s1210_state *st) +{ + unsigned int data; + data = (gpio_get_value(st->res0) << 1) | + gpio_get_value(st->res1); + return resolution_value[data]; +} +#elif defined(CONFIG_AD2S1210_GPIO_OUTPUT) +static inline void set_resolution_pin(struct ad2s1210_state *st) +{ + switch (st->resolution) { + case RES_10: + gpio_set_value(st->res0, 0); + gpio_set_value(st->res1, 0); + break; + case RES_12: + gpio_set_value(st->res0, 0); + gpio_set_value(st->res1, 1); + break; + case RES_14: + gpio_set_value(st->res0, 1); + gpio_set_value(st->res1, 0); + break; + case RES_16: + gpio_set_value(st->res0, 1); + gpio_set_value(st->res1, 1); + break; + } +} +#endif + +static inline void soft_reset(struct ad2s1210_state *st) +{ + config_write(st, REG_SOFT_RESET); + config_write(st, 0x0); +} + + +/* return the OLD DATA since last spi bus write */ +static ssize_t ad2s1210_show_raw(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + int ret; + + mutex_lock(&st->lock); + if (st->old_data) { + ret = sprintf(buf, "0x%x\n", st->rx[0]); + st->old_data = 0; + } else + ret = 0; + mutex_unlock(&st->lock); + return ret; +} + +static ssize_t ad2s1210_store_raw(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned long udata; + unsigned char data; + int ret; + + ret = strict_strtoul(buf, 16, &udata); + if (ret) + return -EINVAL; + data = udata & 0xff; + mutex_lock(&st->lock); + config_write(st, data); + mutex_unlock(&st->lock); + return 1; +} + +static ssize_t ad2s1210_store_softreset(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + mutex_lock(&st->lock); + soft_reset(st); + mutex_unlock(&st->lock); + return len; +} + +static ssize_t ad2s1210_show_fclkin(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + return sprintf(buf, "%d\n", st->fclkin); +} + +static ssize_t ad2s1210_store_fclkin(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned long fclkin; + int ret; + + ret = strict_strtoul(buf, 10, &fclkin); + if (!ret && fclkin >= AD2S1210_MIN_CLKIN && + fclkin <= AD2S1210_MAX_CLKIN) { + mutex_lock(&st->lock); + st->fclkin = fclkin; + } else { + pr_err("ad2s1210: fclkin out of range\n"); + return -EINVAL; + } + update_frequency_control_word(st); + soft_reset(st); + mutex_unlock(&st->lock); + return len; +} + +static ssize_t ad2s1210_show_fexcit(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + return sprintf(buf, "%d\n", st->fexcit); +} + +static ssize_t ad2s1210_store_fexcit(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned long fexcit; + int ret; + + ret = strict_strtoul(buf, 10, &fexcit); + if (!ret && fexcit >= AD2S1210_MIN_EXCIT && + fexcit <= AD2S1210_MAX_EXCIT) { + mutex_lock(&st->lock); + st->fexcit = fexcit; + } else { + pr_err("ad2s1210: excitation frequency out of range\n"); + return -EINVAL; + } + update_frequency_control_word(st); + soft_reset(st); + mutex_unlock(&st->lock); + return len; +} + +static ssize_t ad2s1210_show_control(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned char data; + mutex_lock(&st->lock); + config_read(st, REG_CONTROL, &data); + mutex_unlock(&st->lock); + return sprintf(buf, "0x%x\n", data); +} + +static ssize_t ad2s1210_store_control(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned long udata; + unsigned char data; + int ret; + + ret = strict_strtoul(buf, 16, &udata); + if (ret) { + ret = -EINVAL; + goto error_ret; + } + mutex_lock(&st->lock); + config_write(st, REG_CONTROL); + data = udata & MSB_IS_LOW; + config_write(st, data); + config_read(st, REG_CONTROL, &data); + if (data & MSB_IS_HIGH) { + ret = -EIO; + pr_err("ad2s1210: write control register fail\n"); + goto error_ret; + } + st->resolution = resolution_value[data & SET_RESOLUTION]; +#if defined(CONFIG_AD2S1210_GPIO_INPUT) + data = read_resolution_pin(st); + if (data != st->resolution) + pr_warning("ad2s1210: resolution settings not match\n"); +#elif defined(CONFIG_AD2S1210_GPIO_OUTPUT) + set_resolution_pin(st); +#endif + ret = len; + if (data & ENABLE_HYSTERESIS) + st->hysteresis = 1; + else + st->hysteresis = 0; +error_ret: + mutex_unlock(&st->lock); + return ret; +} + +static ssize_t ad2s1210_show_resolution(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + return sprintf(buf, "%d\n", st->resolution); +} + +static ssize_t ad2s1210_store_resolution(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned char data; + unsigned long udata; + int ret; + + ret = strict_strtoul(buf, 10, &udata); + if (ret || udata < RES_10 || udata > RES_16) { + pr_err("ad2s1210: resolution out of range\n"); + return -EINVAL; + } + mutex_lock(&st->lock); + config_read(st, REG_CONTROL, &data); + data &= ~SET_RESOLUTION; + data |= (udata - RES_10) >> 1; + config_write(st, REG_CONTROL); + config_write(st, data & MSB_IS_LOW); + config_read(st, REG_CONTROL, &data); + if (data & MSB_IS_HIGH) { + ret = -EIO; + pr_err("ad2s1210: setting resolution fail\n"); + goto error_ret; + } + st->resolution = resolution_value[data & SET_RESOLUTION]; +#if defined(CONFIG_AD2S1210_GPIO_INPUT) + data = read_resolution_pin(st); + if (data != st->resolution) + pr_warning("ad2s1210: resolution settings not match\n"); +#elif defined(CONFIG_AD2S1210_GPIO_OUTPUT) + set_resolution_pin(st); +#endif + ret = len; +error_ret: + mutex_unlock(&st->lock); + return ret; +} +/* read the fault register since last sample */ +static ssize_t ad2s1210_show_fault(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int ret = 0; + ssize_t len = 0; + unsigned char data; + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + + mutex_lock(&st->lock); + ret = config_read(st, REG_FAULT, &data); + + if (ret) + goto error_ret; + len = sprintf(buf, "0x%x\n", data); +error_ret: + mutex_unlock(&st->lock); + return ret ? ret : len; +} + +static ssize_t ad2s1210_clear_fault(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned char data; + + mutex_lock(&st->lock); + start_sample(st); + /* delay (2 * tck + 20) nano seconds */ + udelay(1); + stop_sample(st); + config_read(st, REG_FAULT, &data); + start_sample(st); + stop_sample(st); + mutex_unlock(&st->lock); + + return 0; +} + +static ssize_t ad2s1210_show_reg(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned char data; + struct iio_dev_attr *iattr = to_iio_dev_attr(attr); + + mutex_lock(&st->lock); + config_read(st, iattr->address, &data); + mutex_unlock(&st->lock); + return sprintf(buf, "%d\n", data); +} + +static ssize_t ad2s1210_store_reg(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + unsigned long data; + int ret; + struct iio_dev_attr *iattr = to_iio_dev_attr(attr); + + ret = strict_strtoul(buf, 10, &data); + if (ret) + return -EINVAL; + mutex_lock(&st->lock); + config_write(st, iattr->address); + config_write(st, data & MSB_IS_LOW); + mutex_unlock(&st->lock); + return len; +} + +static ssize_t ad2s1210_show_pos(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct spi_message msg; + int ret = 0; + ssize_t len = 0; + u16 pos; + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + + st->xfer.len = 2; + mutex_lock(&st->lock); + start_sample(st); + /* delay (6 * tck + 20) nano seconds */ + udelay(1); + + set_mode(MOD_POS, st); + + spi_message_init(&msg); + spi_message_add_tail(&st->xfer, &msg); + ret = spi_sync(st->sdev, &msg); + if (ret) + goto error_ret; + pos = ((((u16)(st->rx[0])) << 8) | (st->rx[1])); + if (st->hysteresis) + pos >>= 16 - st->resolution; + len = sprintf(buf, "%d\n", pos); +error_ret: + stop_sample(st); + /* delay (2 * tck + 20) nano seconds */ + udelay(1); + mutex_unlock(&st->lock); + + return ret ? ret : len; +} + +static ssize_t ad2s1210_show_vel(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct spi_message msg; + unsigned short negative; + int ret = 0; + ssize_t len = 0; + s16 vel; + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + + st->xfer.len = 2; + mutex_lock(&st->lock); + start_sample(st); + /* delay (6 * tck + 20) nano seconds */ + udelay(1); + + set_mode(MOD_VEL, st); + + spi_message_init(&msg); + spi_message_add_tail(&st->xfer, &msg); + ret = spi_sync(st->sdev, &msg); + if (ret) + goto error_ret; + negative = st->rx[0] & 0x80; + vel = ((((s16)(st->rx[0])) << 8) | (st->rx[1])); + vel >>= 16 - st->resolution; + if (negative) { + negative = (0xffff >> st->resolution) << st->resolution; + vel |= negative; + } + len = sprintf(buf, "%d\n", vel); +error_ret: + stop_sample(st); + /* delay (2 * tck + 20) nano seconds */ + udelay(1); + mutex_unlock(&st->lock); + + return ret ? ret : len; +} + +static ssize_t ad2s1210_show_pos_vel(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct spi_message msg; + unsigned short negative; + int ret = 0; + ssize_t len = 0; + u16 pos; + s16 vel; + struct iio_dev *idev = dev_get_drvdata(dev); + struct ad2s1210_state *st = idev->dev_data; + + st->xfer.len = 2; + mutex_lock(&st->lock); + start_sample(st); + /* delay (6 * tck + 20) nano seconds */ + udelay(1); + + set_mode(MOD_POS, st); + + spi_message_init(&msg); + spi_message_add_tail(&st->xfer, &msg); + ret = spi_sync(st->sdev, &msg); + if (ret) + goto error_ret; + pos = ((((u16)(st->rx[0])) << 8) | (st->rx[1])); + if (st->hysteresis) + pos >>= 16 - st->resolution; + len = sprintf(buf, "%d ", pos); + + st->xfer.len = 2; + set_mode(MOD_VEL, st); + spi_message_init(&msg); + spi_message_add_tail(&st->xfer, &msg); + ret = spi_sync(st->sdev, &msg); + if (ret) + goto error_ret; + negative = st->rx[0] & 0x80; + vel = ((((s16)(st->rx[0])) << 8) | (st->rx[1])); + vel >>= 16 - st->resolution; + if (negative) { + negative = (0xffff >> st->resolution) << st->resolution; + vel |= negative; + } + len += sprintf(buf + len, "%d\n", vel); +error_ret: + stop_sample(st); + /* delay (2 * tck + 20) nano seconds */ + udelay(1); + mutex_unlock(&st->lock); + + return ret ? ret : len; +} + +static IIO_CONST_ATTR(description, + "Variable Resolution, 10-Bit to 16Bit R/D\n\ +Converter with Reference Oscillator"); +static IIO_DEVICE_ATTR(raw_io, S_IRUGO | S_IWUSR, + ad2s1210_show_raw, ad2s1210_store_raw, 0); +static IIO_DEVICE_ATTR(reset, S_IWUSR, + NULL, ad2s1210_store_softreset, 0); +static IIO_DEVICE_ATTR(fclkin, S_IRUGO | S_IWUSR, + ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0); +static IIO_DEVICE_ATTR(fexcit, S_IRUGO | S_IWUSR, + ad2s1210_show_fexcit, ad2s1210_store_fexcit, 0); +static IIO_DEVICE_ATTR(control, S_IRUGO | S_IWUSR, + ad2s1210_show_control, ad2s1210_store_control, 0); +static IIO_DEVICE_ATTR(bits, S_IRUGO | S_IWUSR, + ad2s1210_show_resolution, ad2s1210_store_resolution, 0); +static IIO_DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, + ad2s1210_show_fault, ad2s1210_clear_fault, 0); +static IIO_DEVICE_ATTR(pos, S_IRUGO, + ad2s1210_show_pos, NULL, 0); +static IIO_DEVICE_ATTR(vel, S_IRUGO, + ad2s1210_show_vel, NULL, 0); +static IIO_DEVICE_ATTR(pos_vel, S_IRUGO, + ad2s1210_show_pos_vel, NULL, 0); +static IIO_DEVICE_ATTR(los_thrd, S_IRUGO | S_IWUSR, + ad2s1210_show_reg, ad2s1210_store_reg, REG_LOS_THRD); +static IIO_DEVICE_ATTR(dos_ovr_thrd, S_IRUGO | S_IWUSR, + ad2s1210_show_reg, ad2s1210_store_reg, REG_DOS_OVR_THRD); +static IIO_DEVICE_ATTR(dos_mis_thrd, S_IRUGO | S_IWUSR, + ad2s1210_show_reg, ad2s1210_store_reg, REG_DOS_MIS_THRD); +static IIO_DEVICE_ATTR(dos_rst_max_thrd, S_IRUGO | S_IWUSR, + ad2s1210_show_reg, ad2s1210_store_reg, REG_DOS_RST_MAX_THRD); +static IIO_DEVICE_ATTR(dos_rst_min_thrd, S_IRUGO | S_IWUSR, + ad2s1210_show_reg, ad2s1210_store_reg, REG_DOS_RST_MIN_THRD); +static IIO_DEVICE_ATTR(lot_high_thrd, S_IRUGO | S_IWUSR, + ad2s1210_show_reg, ad2s1210_store_reg, REG_LOT_HIGH_THRD); +static IIO_DEVICE_ATTR(lot_low_thrd, S_IRUGO | S_IWUSR, + ad2s1210_show_reg, ad2s1210_store_reg, REG_LOT_LOW_THRD); + +static struct attribute *ad2s1210_attributes[] = { + &iio_const_attr_description.dev_attr.attr, + &iio_dev_attr_raw_io.dev_attr.attr, + &iio_dev_attr_reset.dev_attr.attr, + &iio_dev_attr_fclkin.dev_attr.attr, + &iio_dev_attr_fexcit.dev_attr.attr, + &iio_dev_attr_control.dev_attr.attr, + &iio_dev_attr_bits.dev_attr.attr, + &iio_dev_attr_fault.dev_attr.attr, + &iio_dev_attr_pos.dev_attr.attr, + &iio_dev_attr_vel.dev_attr.attr, + &iio_dev_attr_pos_vel.dev_attr.attr, + &iio_dev_attr_los_thrd.dev_attr.attr, + &iio_dev_attr_dos_ovr_thrd.dev_attr.attr, + &iio_dev_attr_dos_mis_thrd.dev_attr.attr, + &iio_dev_attr_dos_rst_max_thrd.dev_attr.attr, + &iio_dev_attr_dos_rst_min_thrd.dev_attr.attr, + &iio_dev_attr_lot_high_thrd.dev_attr.attr, + &iio_dev_attr_lot_low_thrd.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ad2s1210_attribute_group = { + .name = DRV_NAME, + .attrs = ad2s1210_attributes, +}; + +static int __devinit ad2s1210_initial(struct ad2s1210_state *st) +{ + unsigned char data; + int ret; + + mutex_lock(&st->lock); +#if defined(CONFIG_AD2S1210_GPIO_INPUT) + st->resolution = read_resolution_pin(st); +#elif defined(CONFIG_AD2S1210_GPIO_OUTPUT) + set_resolution_pin(st); +#endif + + config_write(st, REG_CONTROL); + data = DEF_CONTROL & ~(SET_RESOLUTION); + data |= (st->resolution - RES_10) >> 1; + config_write(st, data); + ret = config_read(st, REG_CONTROL, &data); + if (ret) + goto error_ret; + + if (data & MSB_IS_HIGH) { + ret = -EIO; + goto error_ret; + } + + update_frequency_control_word(st); + soft_reset(st); +error_ret: + mutex_unlock(&st->lock); + return ret; +} + +static int __devinit ad2s1210_probe(struct spi_device *spi) +{ + struct ad2s1210_state *st; + int pn, ret = 0; + unsigned short *pins = spi->dev.platform_data; + + for (pn = 0; pn < AD2S1210_PN; pn++) { + if (gpio_request(pins[pn], DRV_NAME)) { + pr_err("%s: request gpio pin %d failed\n", + DRV_NAME, pins[pn]); + goto error_ret; + } + if (pn < AD2S1210_SAA) + gpio_direction_output(pins[pn], 1); + else { +#if defined(CONFIG_AD2S1210_GPIO_INPUT) + gpio_direction_input(pins[pn]); +#elif defined(CONFIG_AD2S1210_GPIO_OUTPUT) + gpio_direction_output(pins[pn], 1); +#endif + } + } + + st = kzalloc(sizeof(*st), GFP_KERNEL); + if (st == NULL) { + ret = -ENOMEM; + goto error_ret; + } + spi_set_drvdata(spi, st); + + mutex_init(&st->lock); + st->sdev = spi; + st->xfer.tx_buf = st->tx; + st->xfer.rx_buf = st->rx; + st->hysteresis = 1; + st->mode = MOD_CONFIG; + st->resolution = RES_12; + st->fclkin = AD2S1210_DEF_CLKIN; + st->fexcit = AD2S1210_DEF_EXCIT; + st->sample = pins[0]; + st->a0 = pins[1]; + st->a1 = pins[2]; + st->res0 = pins[3]; + st->res1 = pins[4]; + + st->idev = iio_allocate_device(); + if (st->idev == NULL) { + ret = -ENOMEM; + goto error_free_st; + } + st->idev->dev.parent = &spi->dev; + st->idev->num_interrupt_lines = 0; + st->idev->event_attrs = NULL; + + st->idev->attrs = &ad2s1210_attribute_group; + st->idev->dev_data = (void *)(st); + st->idev->driver_module = THIS_MODULE; + st->idev->modes = INDIO_DIRECT_MODE; + + ret = iio_device_register(st->idev); + if (ret) + goto error_free_dev; + + if (spi->max_speed_hz != AD2S1210_DEF_CLKIN) + st->fclkin = spi->max_speed_hz; + spi->mode = SPI_MODE_3; + spi_setup(spi); + + ad2s1210_initial(st); + return 0; + +error_free_dev: + iio_free_device(st->idev); +error_free_st: + kfree(st); +error_ret: + for (--pn; pn >= 0; pn--) + gpio_free(pins[pn]); + return ret; +} + +static int __devexit ad2s1210_remove(struct spi_device *spi) +{ + struct ad2s1210_state *st = spi_get_drvdata(spi); + + iio_device_unregister(st->idev); + kfree(st); + + return 0; +} + +static struct spi_driver ad2s1210_driver = { + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, + .probe = ad2s1210_probe, + .remove = __devexit_p(ad2s1210_remove), +}; + +static __init int ad2s1210_spi_init(void) +{ + return spi_register_driver(&ad2s1210_driver); +} +module_init(ad2s1210_spi_init); + +static __exit void ad2s1210_spi_exit(void) +{ + spi_unregister_driver(&ad2s1210_driver); +} +module_exit(ad2s1210_spi_exit); + +MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>"); +MODULE_DESCRIPTION("Analog Devices AD2S1210 Resolver to Digital SPI driver"); +MODULE_LICENSE("GPL v2"); |