Input: ads7846 - be more compatible with the hwmon framework
- Hook up to hwmon
* show sensor attributes only if hwmon is present
* ... and the board's reference voltage is known
* otherwise be just a touchscreen
- Report voltages per hwmon convention
* measure in millivolts
* voltages are named in[0-8]_input (ugh)
* for 7846 chips, properly range-adjust vBATT/in1_input
Battery measurements help during recharge monitoring. On OSK/Mistral,
the measured voltage agreed with a multimeter to several decimal places.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
David Brownell
Dmitry Torokhov
parent
15e3589e59
commit
2c8dc07151
|
|
@ -12,13 +12,18 @@ menuconfig INPUT_TOUCHSCREEN
|
|||
if INPUT_TOUCHSCREEN
|
||||
|
||||
config TOUCHSCREEN_ADS7846
|
||||
tristate "ADS 7846 based touchscreens"
|
||||
tristate "ADS 7846/7843 based touchscreens"
|
||||
depends on SPI_MASTER
|
||||
depends on HWMON = n || HWMON
|
||||
help
|
||||
Say Y here if you have a touchscreen interface using the
|
||||
ADS7846 controller, and your board-specific initialization
|
||||
ADS7846 or ADS7843 controller, and your board-specific setup
|
||||
code includes that in its table of SPI devices.
|
||||
|
||||
If HWMON is selected, and the driver is told the reference voltage
|
||||
on your board, you will also get hwmon interfaces for the voltage
|
||||
(and on ads7846, temperature) sensors of this chip.
|
||||
|
||||
If unsure, say N (but it's safe to say "Y").
|
||||
|
||||
To compile this driver as a module, choose M here: the
|
||||
|
|
|
|||
|
|
@ -17,8 +17,9 @@
|
|||
* it under the terms of the GNU General Public License version 2 as
|
||||
* published by the Free Software Foundation.
|
||||
*/
|
||||
#include <linux/device.h>
|
||||
#include <linux/hwmon.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/input.h>
|
||||
#include <linux/interrupt.h>
|
||||
|
|
@ -69,7 +70,7 @@ struct ts_event {
|
|||
u16 x;
|
||||
u16 y;
|
||||
u16 z1, z2;
|
||||
int ignore;
|
||||
int ignore;
|
||||
};
|
||||
|
||||
struct ads7846 {
|
||||
|
|
@ -77,7 +78,12 @@ struct ads7846 {
|
|||
char phys[32];
|
||||
|
||||
struct spi_device *spi;
|
||||
|
||||
#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
|
||||
struct attribute_group *attr_group;
|
||||
struct class_device *hwmon;
|
||||
#endif
|
||||
|
||||
u16 model;
|
||||
u16 vref_delay_usecs;
|
||||
u16 x_plate_ohms;
|
||||
|
|
@ -170,7 +176,12 @@ struct ads7846 {
|
|||
|
||||
/*
|
||||
* Non-touchscreen sensors only use single-ended conversions.
|
||||
* The range is GND..vREF. The ads7843 and ads7835 must use external vREF;
|
||||
* ads7846 lets that pin be unconnected, to use internal vREF.
|
||||
*/
|
||||
static unsigned vREF_mV;
|
||||
module_param(vREF_mV, uint, 0);
|
||||
MODULE_PARM_DESC(vREF_mV, "external vREF voltage, in milliVolts");
|
||||
|
||||
struct ser_req {
|
||||
u8 ref_on;
|
||||
|
|
@ -198,50 +209,55 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
|
|||
struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
|
||||
int status;
|
||||
int sample;
|
||||
int i;
|
||||
int use_internal;
|
||||
|
||||
if (!req)
|
||||
return -ENOMEM;
|
||||
|
||||
spi_message_init(&req->msg);
|
||||
|
||||
/* activate reference, so it has time to settle; */
|
||||
req->ref_on = REF_ON;
|
||||
req->xfer[0].tx_buf = &req->ref_on;
|
||||
req->xfer[0].len = 1;
|
||||
req->xfer[1].rx_buf = &req->scratch;
|
||||
req->xfer[1].len = 2;
|
||||
/* FIXME boards with ads7846 might use external vref instead ... */
|
||||
use_internal = (ts->model == 7846);
|
||||
|
||||
/*
|
||||
* for external VREF, 0 usec (and assume it's always on);
|
||||
* for 1uF, use 800 usec;
|
||||
* no cap, 100 usec.
|
||||
*/
|
||||
req->xfer[1].delay_usecs = ts->vref_delay_usecs;
|
||||
/* maybe turn on internal vREF, and let it settle */
|
||||
if (use_internal) {
|
||||
req->ref_on = REF_ON;
|
||||
req->xfer[0].tx_buf = &req->ref_on;
|
||||
req->xfer[0].len = 1;
|
||||
spi_message_add_tail(&req->xfer[0], &req->msg);
|
||||
|
||||
req->xfer[1].rx_buf = &req->scratch;
|
||||
req->xfer[1].len = 2;
|
||||
|
||||
/* for 1uF, settle for 800 usec; no cap, 100 usec. */
|
||||
req->xfer[1].delay_usecs = ts->vref_delay_usecs;
|
||||
spi_message_add_tail(&req->xfer[1], &req->msg);
|
||||
}
|
||||
|
||||
/* take sample */
|
||||
req->command = (u8) command;
|
||||
req->xfer[2].tx_buf = &req->command;
|
||||
req->xfer[2].len = 1;
|
||||
spi_message_add_tail(&req->xfer[2], &req->msg);
|
||||
|
||||
req->xfer[3].rx_buf = &req->sample;
|
||||
req->xfer[3].len = 2;
|
||||
spi_message_add_tail(&req->xfer[3], &req->msg);
|
||||
|
||||
/* REVISIT: take a few more samples, and compare ... */
|
||||
|
||||
/* turn off reference */
|
||||
req->ref_off = REF_OFF;
|
||||
req->xfer[4].tx_buf = &req->ref_off;
|
||||
req->xfer[4].len = 1;
|
||||
req->xfer[5].rx_buf = &req->scratch;
|
||||
req->xfer[5].len = 2;
|
||||
/* maybe off internal vREF */
|
||||
if (use_internal) {
|
||||
req->ref_off = REF_OFF;
|
||||
req->xfer[4].tx_buf = &req->ref_off;
|
||||
req->xfer[4].len = 1;
|
||||
spi_message_add_tail(&req->xfer[4], &req->msg);
|
||||
|
||||
CS_CHANGE(req->xfer[5]);
|
||||
|
||||
/* group all the transfers together, so we can't interfere with
|
||||
* reading touchscreen state; disable penirq while sampling
|
||||
*/
|
||||
for (i = 0; i < 6; i++)
|
||||
spi_message_add_tail(&req->xfer[i], &req->msg);
|
||||
req->xfer[5].rx_buf = &req->scratch;
|
||||
req->xfer[5].len = 2;
|
||||
CS_CHANGE(req->xfer[5]);
|
||||
spi_message_add_tail(&req->xfer[5], &req->msg);
|
||||
}
|
||||
|
||||
ts->irq_disabled = 1;
|
||||
disable_irq(spi->irq);
|
||||
|
|
@ -261,25 +277,173 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
|
|||
return status ? status : sample;
|
||||
}
|
||||
|
||||
#define SHOW(name) static ssize_t \
|
||||
#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE)
|
||||
|
||||
#define SHOW(name, var, adjust) static ssize_t \
|
||||
name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
|
||||
{ \
|
||||
struct ads7846 *ts = dev_get_drvdata(dev); \
|
||||
ssize_t v = ads7846_read12_ser(dev, \
|
||||
READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \
|
||||
READ_12BIT_SER(var) | ADS_PD10_ALL_ON); \
|
||||
if (v < 0) \
|
||||
return v; \
|
||||
return sprintf(buf, "%u\n", (unsigned) v); \
|
||||
return sprintf(buf, "%u\n", adjust(ts, v)); \
|
||||
} \
|
||||
static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
|
||||
|
||||
SHOW(temp0)
|
||||
SHOW(temp1)
|
||||
SHOW(vaux)
|
||||
SHOW(vbatt)
|
||||
|
||||
/* Sysfs conventions report temperatures in millidegrees Celcius.
|
||||
* ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
|
||||
* accuracy scheme without calibration data. For now we won't try either;
|
||||
* userspace sees raw sensor values, and must scale/calibrate appropriately.
|
||||
*/
|
||||
static inline unsigned null_adjust(struct ads7846 *ts, ssize_t v)
|
||||
{
|
||||
return v;
|
||||
}
|
||||
|
||||
SHOW(temp0, temp0, null_adjust) /* temp1_input */
|
||||
SHOW(temp1, temp1, null_adjust) /* temp2_input */
|
||||
|
||||
|
||||
/* sysfs conventions report voltages in millivolts. We can convert voltages
|
||||
* if we know vREF. userspace may need to scale vAUX to match the board's
|
||||
* external resistors; we assume that vBATT only uses the internal ones.
|
||||
*/
|
||||
static inline unsigned vaux_adjust(struct ads7846 *ts, ssize_t v)
|
||||
{
|
||||
unsigned retval = v;
|
||||
|
||||
/* external resistors may scale vAUX into 0..vREF */
|
||||
retval *= vREF_mV;
|
||||
retval = retval >> 12;
|
||||
return retval;
|
||||
}
|
||||
|
||||
static inline unsigned vbatt_adjust(struct ads7846 *ts, ssize_t v)
|
||||
{
|
||||
unsigned retval = vaux_adjust(ts, v);
|
||||
|
||||
/* ads7846 has a resistor ladder to scale this signal down */
|
||||
if (ts->model == 7846)
|
||||
retval *= 4;
|
||||
return retval;
|
||||
}
|
||||
|
||||
SHOW(in0_input, vaux, vaux_adjust)
|
||||
SHOW(in1_input, vbatt, vbatt_adjust)
|
||||
|
||||
|
||||
static struct attribute *ads7846_attributes[] = {
|
||||
&dev_attr_temp0.attr,
|
||||
&dev_attr_temp1.attr,
|
||||
&dev_attr_in0_input.attr,
|
||||
&dev_attr_in1_input.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static struct attribute_group ads7846_attr_group = {
|
||||
.attrs = ads7846_attributes,
|
||||
};
|
||||
|
||||
static struct attribute *ads7843_attributes[] = {
|
||||
&dev_attr_in0_input.attr,
|
||||
&dev_attr_in1_input.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static struct attribute_group ads7843_attr_group = {
|
||||
.attrs = ads7843_attributes,
|
||||
};
|
||||
|
||||
static struct attribute *ads7845_attributes[] = {
|
||||
&dev_attr_in0_input.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static struct attribute_group ads7845_attr_group = {
|
||||
.attrs = ads7845_attributes,
|
||||
};
|
||||
|
||||
static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
|
||||
{
|
||||
struct class_device *hwmon;
|
||||
int err;
|
||||
|
||||
/* hwmon sensors need a reference voltage */
|
||||
switch (ts->model) {
|
||||
case 7846:
|
||||
if (!vREF_mV) {
|
||||
dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n");
|
||||
vREF_mV = 2500;
|
||||
}
|
||||
break;
|
||||
case 7845:
|
||||
case 7843:
|
||||
if (!vREF_mV) {
|
||||
dev_warn(&spi->dev,
|
||||
"external vREF for ADS%d not specified\n",
|
||||
ts->model);
|
||||
return 0;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
/* different chips have different sensor groups */
|
||||
switch (ts->model) {
|
||||
case 7846:
|
||||
ts->attr_group = &ads7846_attr_group;
|
||||
break;
|
||||
case 7845:
|
||||
ts->attr_group = &ads7845_attr_group;
|
||||
break;
|
||||
case 7843:
|
||||
ts->attr_group = &ads7843_attr_group;
|
||||
break;
|
||||
default:
|
||||
dev_dbg(&spi->dev, "ADS%d not recognized\n", ts->model);
|
||||
return 0;
|
||||
}
|
||||
|
||||
err = sysfs_create_group(&spi->dev.kobj, ts->attr_group);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
hwmon = hwmon_device_register(&spi->dev);
|
||||
if (IS_ERR(hwmon)) {
|
||||
sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
|
||||
return PTR_ERR(hwmon);
|
||||
}
|
||||
|
||||
ts->hwmon = hwmon;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void ads784x_hwmon_unregister(struct spi_device *spi,
|
||||
struct ads7846 *ts)
|
||||
{
|
||||
if (ts->hwmon) {
|
||||
sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
|
||||
hwmon_device_unregister(ts->hwmon);
|
||||
}
|
||||
}
|
||||
|
||||
#else
|
||||
static inline int ads784x_hwmon_register(struct spi_device *spi,
|
||||
struct ads7846 *ts)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void ads784x_hwmon_unregister(struct spi_device *spi,
|
||||
struct ads7846 *ts)
|
||||
{
|
||||
}
|
||||
#endif
|
||||
|
||||
static int is_pen_down(struct device *dev)
|
||||
{
|
||||
struct ads7846 *ts = dev_get_drvdata(dev);
|
||||
struct ads7846 *ts = dev_get_drvdata(dev);
|
||||
|
||||
return ts->pendown;
|
||||
}
|
||||
|
|
@ -323,46 +487,14 @@ static ssize_t ads7846_disable_store(struct device *dev,
|
|||
|
||||
static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
|
||||
|
||||
static struct attribute *ads7846_attributes[] = {
|
||||
&dev_attr_temp0.attr,
|
||||
&dev_attr_temp1.attr,
|
||||
&dev_attr_vbatt.attr,
|
||||
&dev_attr_vaux.attr,
|
||||
static struct attribute *ads784x_attributes[] = {
|
||||
&dev_attr_pen_down.attr,
|
||||
&dev_attr_disable.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static struct attribute_group ads7846_attr_group = {
|
||||
.attrs = ads7846_attributes,
|
||||
};
|
||||
|
||||
/*
|
||||
* ads7843/7845 don't have temperature sensors, and
|
||||
* use the other sensors a bit differently too
|
||||
*/
|
||||
|
||||
static struct attribute *ads7843_attributes[] = {
|
||||
&dev_attr_vbatt.attr,
|
||||
&dev_attr_vaux.attr,
|
||||
&dev_attr_pen_down.attr,
|
||||
&dev_attr_disable.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static struct attribute_group ads7843_attr_group = {
|
||||
.attrs = ads7843_attributes,
|
||||
};
|
||||
|
||||
static struct attribute *ads7845_attributes[] = {
|
||||
&dev_attr_vaux.attr,
|
||||
&dev_attr_pen_down.attr,
|
||||
&dev_attr_disable.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static struct attribute_group ads7845_attr_group = {
|
||||
.attrs = ads7845_attributes,
|
||||
static struct attribute_group ads784x_attr_group = {
|
||||
.attrs = ads784x_attributes,
|
||||
};
|
||||
|
||||
/*--------------------------------------------------------------------------*/
|
||||
|
|
@ -886,28 +1018,21 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|||
goto err_cleanup_filter;
|
||||
}
|
||||
|
||||
err = ads784x_hwmon_register(spi, ts);
|
||||
if (err)
|
||||
goto err_free_irq;
|
||||
|
||||
dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
|
||||
|
||||
/* take a first sample, leaving nPENIRQ active; avoid
|
||||
/* take a first sample, leaving nPENIRQ active and vREF off; avoid
|
||||
* the touchscreen, in case it's not connected.
|
||||
*/
|
||||
(void) ads7846_read12_ser(&spi->dev,
|
||||
READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
|
||||
|
||||
switch (ts->model) {
|
||||
case 7846:
|
||||
ts->attr_group = &ads7846_attr_group;
|
||||
break;
|
||||
case 7845:
|
||||
ts->attr_group = &ads7845_attr_group;
|
||||
break;
|
||||
default:
|
||||
ts->attr_group = &ads7843_attr_group;
|
||||
break;
|
||||
}
|
||||
err = sysfs_create_group(&spi->dev.kobj, ts->attr_group);
|
||||
err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
|
||||
if (err)
|
||||
goto err_free_irq;
|
||||
goto err_remove_hwmon;
|
||||
|
||||
err = input_register_device(input_dev);
|
||||
if (err)
|
||||
|
|
@ -916,7 +1041,9 @@ static int __devinit ads7846_probe(struct spi_device *spi)
|
|||
return 0;
|
||||
|
||||
err_remove_attr_group:
|
||||
sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
|
||||
sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
|
||||
err_remove_hwmon:
|
||||
ads784x_hwmon_unregister(spi, ts);
|
||||
err_free_irq:
|
||||
free_irq(spi->irq, ts);
|
||||
err_cleanup_filter:
|
||||
|
|
@ -932,11 +1059,12 @@ static int __devexit ads7846_remove(struct spi_device *spi)
|
|||
{
|
||||
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
|
||||
|
||||
ads784x_hwmon_unregister(spi, ts);
|
||||
input_unregister_device(ts->input);
|
||||
|
||||
ads7846_suspend(spi, PMSG_SUSPEND);
|
||||
|
||||
sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
|
||||
sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
|
||||
|
||||
free_irq(ts->spi->irq, ts);
|
||||
/* suspend left the IRQ disabled */
|
||||
|
|
|
|||
Reference in New Issue