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iio: mxs-lradc: add scale_available file to channels 

Adds in_voltageX_scale_available file for every channel to read
the different available scales.
There are two scales per channel:
 [0] = divider_by_two disabled (default)
 [1] = divider_by_two enabled
The scale is a struct made of integer and nano parts to build
a long decimal number.

Signed-off-by: Hector Palacios <hector.palacios@digi.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Hector Palacios 2013-12-23 17:48:00 +00:00 committed by Jonathan Cameron
parent f6db68a405
commit d5acf5942b
1 changed files with 105 additions and 1 deletions
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106
drivers/staging/iio/adc/mxs-lradc.c
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@ -38,6 +38,7 @@
#include <linux/clk.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
@ -184,6 +185,11 @@ enum lradc_ts_plate {
LRADC_SAMPLE_VALID,
};
struct mxs_lradc_scale {
unsigned int integer;
unsigned int nano;
};
struct mxs_lradc {
struct device *dev;
void __iomem *base;
@ -199,6 +205,7 @@ struct mxs_lradc {
struct completion completion;
const uint32_t *vref_mv;
struct mxs_lradc_scale scale_avail[LRADC_MAX_TOTAL_CHANS][2];
/*
* Touchscreen LRADC channels receives a private slot in the CTRL4
@ -929,9 +936,84 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
return -EINVAL;
}
static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
struct device_attribute *attr,
char *buf,
int ch)
{
struct iio_dev *iio = dev_to_iio_dev(dev);
struct mxs_lradc *lradc = iio_priv(iio);
int i, len = 0;
for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
len += sprintf(buf + len, "%d.%09u ",
lradc->scale_avail[ch][i].integer,
lradc->scale_avail[ch][i].nano);
len += sprintf(buf + len, "\n");
return len;
}
static ssize_t mxs_lradc_show_scale_available(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
return mxs_lradc_show_scale_available_ch(dev, attr, buf,
iio_attr->address);
}
#define SHOW_SCALE_AVAILABLE_ATTR(ch) \
static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \
mxs_lradc_show_scale_available, NULL, ch)
SHOW_SCALE_AVAILABLE_ATTR(0);
SHOW_SCALE_AVAILABLE_ATTR(1);
SHOW_SCALE_AVAILABLE_ATTR(2);
SHOW_SCALE_AVAILABLE_ATTR(3);
SHOW_SCALE_AVAILABLE_ATTR(4);
SHOW_SCALE_AVAILABLE_ATTR(5);
SHOW_SCALE_AVAILABLE_ATTR(6);
SHOW_SCALE_AVAILABLE_ATTR(7);
SHOW_SCALE_AVAILABLE_ATTR(8);
SHOW_SCALE_AVAILABLE_ATTR(9);
SHOW_SCALE_AVAILABLE_ATTR(10);
SHOW_SCALE_AVAILABLE_ATTR(11);
SHOW_SCALE_AVAILABLE_ATTR(12);
SHOW_SCALE_AVAILABLE_ATTR(13);
SHOW_SCALE_AVAILABLE_ATTR(14);
SHOW_SCALE_AVAILABLE_ATTR(15);
static struct attribute *mxs_lradc_attributes[] = {
&iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage8_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage9_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
&iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
NULL
};
static const struct attribute_group mxs_lradc_attribute_group = {
.attrs = mxs_lradc_attributes,
};
static const struct iio_info mxs_lradc_iio_info = {
.driver_module = THIS_MODULE,
.read_raw = mxs_lradc_read_raw,
.attrs = &mxs_lradc_attribute_group,
};
static int mxs_lradc_ts_open(struct input_dev *dev)
@ -1241,6 +1323,7 @@ static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.channel = (idx), \
.address = (idx), \
.scan_type = { \
.sign = 'u', \
.realbits = LRADC_RESOLUTION, \
@ -1386,7 +1469,8 @@ static int mxs_lradc_probe(struct platform_device *pdev)
struct iio_dev *iio;
struct resource *iores;
int ret = 0, touch_ret;
int i;
int i, s;
unsigned int scale_uv;
/* Allocate the IIO device. */
iio = devm_iio_device_alloc(dev, sizeof(*lradc));
@ -1456,6 +1540,26 @@ static int mxs_lradc_probe(struct platform_device *pdev)
if (ret)
goto err_trig;
/* Populate available ADC input ranges */
for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
for (s = 0; s < ARRAY_SIZE(lradc->scale_avail[i]); s++) {
/*
* [s=0] = optional divider by two disabled (default)
* [s=1] = optional divider by two enabled
*
* The scale is calculated by doing:
* Vref >> (realbits - s)
* which multiplies by two on the second component
* of the array.
*/
scale_uv = ((u64)lradc->vref_mv[i] * 100000000) >>
(iio->channels[i].scan_type.realbits - s);
lradc->scale_avail[i][s].nano =
do_div(scale_uv, 100000000) * 10;
lradc->scale_avail[i][s].integer = scale_uv;
}
}
/* Configure the hardware. */
ret = mxs_lradc_hw_init(lradc);
if (ret)