#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
+#include <linux/gpio/consumer.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#define AD7768_REG_DIG_DIAG_STATUS 0x30
#define AD7768_REG_MCLK_COUNTER 0x31
+/* AD7768_REG_POWER_CLOCK */
+#define AD7768_PWR_MCLK_DIV_MSK GENMASK(5, 4)
+#define AD7768_PWR_MCLK_DIV(x) FIELD_PREP(AD7768_PWR_MCLK_DIV_MSK, x)
+#define AD7768_PWR_PWRMODE_MSK GENMASK(1, 0)
+#define AD7768_PWR_PWRMODE(x) FIELD_PREP(AD7768_PWR_PWRMODE_MSK, x)
+
+/* AD7768_REG_DIGITAL_FILTER */
+#define AD7768_DIG_FIL_FIL_MSK GENMASK(6, 4)
+#define AD7768_DIG_FIL_FIL(x) FIELD_PREP(AD7768_DIG_FIL_FIL_MSK, x)
+#define AD7768_DIG_FIL_DEC_MSK GENMASK(2, 0)
+#define AD7768_DIG_FIL_DEC_RATE(x) FIELD_PREP(AD7768_DIG_FIL_DEC_MSK, x)
+
/* AD7768_REG_CONVERSION */
#define AD7768_CONV_MODE_MSK GENMASK(2, 0)
#define AD7768_CONV_MODE(x) FIELD_PREP(AD7768_CONV_MODE_MSK, x)
AD7768_FAST_MODE = 3
};
+enum ad7768_mclk_div {
+ AD7768_MCLK_DIV_16,
+ AD7768_MCLK_DIV_8,
+ AD7768_MCLK_DIV_4,
+ AD7768_MCLK_DIV_2
+};
+
+enum ad7768_dec_rate {
+ AD7768_DEC_RATE_32 = 0,
+ AD7768_DEC_RATE_64 = 1,
+ AD7768_DEC_RATE_128 = 2,
+ AD7768_DEC_RATE_256 = 3,
+ AD7768_DEC_RATE_512 = 4,
+ AD7768_DEC_RATE_1024 = 5,
+ AD7768_DEC_RATE_8 = 9,
+ AD7768_DEC_RATE_16 = 10
+};
+
+struct ad7768_clk_configuration {
+ enum ad7768_mclk_div mclk_div;
+ enum ad7768_dec_rate dec_rate;
+ unsigned int clk_div;
+ enum ad7768_pwrmode pwrmode;
+};
+
+static const struct ad7768_clk_configuration ad7768_clk_config[] = {
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_8, 16, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_16, 32, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_32, 64, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_64, 128, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_128, 256, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_128, 512, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_256, 1024, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_512, 2048, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_1024, 4096, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_8, AD7768_DEC_RATE_1024, 8192, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_16, AD7768_DEC_RATE_1024, 16384, AD7768_ECO_MODE },
+};
+
static const struct iio_chan_spec ad7768_channels[] = {
{
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
.indexed = 1,
.channel = 0,
.scan_index = 0,
struct spi_device *spi;
struct regulator *vref;
struct mutex lock;
+ struct clk *mclk;
+ unsigned int mclk_freq;
+ unsigned int samp_freq;
struct completion completion;
struct iio_trigger *trig;
+ struct gpio_desc *gpio_sync_in;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
return ret;
}
+static int ad7768_set_dig_fil(struct ad7768_state *st,
+ enum ad7768_dec_rate dec_rate)
+{
+ unsigned int mode;
+ int ret;
+
+ if (dec_rate == AD7768_DEC_RATE_8 || dec_rate == AD7768_DEC_RATE_16)
+ mode = AD7768_DIG_FIL_FIL(dec_rate);
+ else
+ mode = AD7768_DIG_FIL_DEC_RATE(dec_rate);
+
+ ret = ad7768_spi_reg_write(st, AD7768_REG_DIGITAL_FILTER, mode);
+ if (ret < 0)
+ return ret;
+
+ /* A sync-in pulse is required every time the filter dec rate changes */
+ gpiod_set_value(st->gpio_sync_in, 1);
+ gpiod_set_value(st->gpio_sync_in, 0);
+
+ return 0;
+}
+
+static int ad7768_set_freq(struct ad7768_state *st,
+ unsigned int freq)
+{
+ unsigned int diff_new, diff_old, pwr_mode, i, idx;
+ int res, ret;
+
+ diff_old = U32_MAX;
+ idx = 0;
+
+ res = DIV_ROUND_CLOSEST(st->mclk_freq, freq);
+
+ /* Find the closest match for the desired sampling frequency */
+ for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
+ diff_new = abs(res - ad7768_clk_config[i].clk_div);
+ if (diff_new < diff_old) {
+ diff_old = diff_new;
+ idx = i;
+ }
+ }
+
+ /*
+ * Set both the mclk_div and pwrmode with a single write to the
+ * POWER_CLOCK register
+ */
+ pwr_mode = AD7768_PWR_MCLK_DIV(ad7768_clk_config[idx].mclk_div) |
+ AD7768_PWR_PWRMODE(ad7768_clk_config[idx].pwrmode);
+ ret = ad7768_spi_reg_write(st, AD7768_REG_POWER_CLOCK, pwr_mode);
+ if (ret < 0)
+ return ret;
+
+ ret = ad7768_set_dig_fil(st, ad7768_clk_config[idx].dec_rate);
+ if (ret < 0)
+ return ret;
+
+ st->samp_freq = DIV_ROUND_CLOSEST(st->mclk_freq,
+ ad7768_clk_config[idx].clk_div);
+
+ return 0;
+}
+
+static ssize_t ad7768_sampling_freq_avail(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7768_state *st = iio_priv(indio_dev);
+ unsigned int freq;
+ int i, len = 0;
+
+ for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
+ freq = DIV_ROUND_CLOSEST(st->mclk_freq,
+ ad7768_clk_config[i].clk_div);
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", freq);
+ }
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(ad7768_sampling_freq_avail);
+
static int ad7768_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long info)
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = st->samp_freq;
+
+ return IIO_VAL_INT;
}
return -EINVAL;
}
+static int ad7768_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long info)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ return ad7768_set_freq(st, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static struct attribute *ad7768_attributes[] = {
+ &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group ad7768_group = {
+ .attrs = ad7768_attributes,
+};
+
static const struct iio_info ad7768_info = {
+ .attrs = &ad7768_group,
.read_raw = &ad7768_read_raw,
+ .write_raw = &ad7768_write_raw,
.debugfs_reg_access = &ad7768_reg_access,
};
if (ret)
return ret;
- /* Set power mode to fast */
- return ad7768_spi_reg_write(st, AD7768_REG_POWER_CLOCK,
- AD7768_FAST_MODE);
+ st->gpio_sync_in = devm_gpiod_get(&st->spi->dev, "adi,sync-in",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(st->gpio_sync_in))
+ return PTR_ERR(st->gpio_sync_in);
+
+ /* Set the default sampling frequency to 32000 kSPS */
+ return ad7768_set_freq(st, 32000);
}
static irqreturn_t ad7768_trigger_handler(int irq, void *p)
regulator_disable(st->vref);
}
+static void ad7768_clk_disable(void *data)
+{
+ struct ad7768_state *st = data;
+
+ clk_disable_unprepare(st->mclk);
+}
+
static int ad7768_probe(struct spi_device *spi)
{
struct ad7768_state *st;
if (ret)
return ret;
+ st->mclk = devm_clk_get(&spi->dev, "mclk");
+ if (IS_ERR(st->mclk))
+ return PTR_ERR(st->mclk);
+
+ ret = clk_prepare_enable(st->mclk);
+ if (ret < 0)
+ return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev, ad7768_clk_disable, st);
+ if (ret)
+ return ret;
+
+ st->mclk_freq = clk_get_rate(st->mclk);
+
spi_set_drvdata(spi, indio_dev);
mutex_init(&st->lock);
projects / openwrt / staging / blogic.git / commitdiff