--- /dev/null
+/*
+ * 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");
projects / mv-sheeva.git / blobdiff