1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141 |
- /*
- * ADS7846 based touchscreen and sensor driver
- *
- * Copyright (c) 2005 David Brownell
- * Copyright (c) 2006 Nokia Corporation
- * Various changes: Imre Deak <imre.deak@nokia.com>
- *
- * Using code from:
- * - corgi_ts.c
- * Copyright (C) 2004-2005 Richard Purdie
- * - omap_ts.[hc], ads7846.h, ts_osk.c
- * Copyright (C) 2002 MontaVista Software
- * Copyright (C) 2004 Texas Instruments
- * Copyright (C) 2005 Dirk Behme
- *
- * 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/hwmon.h>
- #include <linux/init.h>
- #include <linux/err.h>
- #include <linux/delay.h>
- #include <linux/input.h>
- #include <linux/interrupt.h>
- #include <linux/slab.h>
- #include <linux/spi/spi.h>
- #include <linux/spi/ads7846.h>
- #include <asm/irq.h>
- #ifdef CONFIG_ARM
- #include <asm/mach-types.h>
- #ifdef CONFIG_ARCH_OMAP
- #include <asm/arch/gpio.h>
- #endif
- #endif
- /*
- * This code has been heavily tested on a Nokia 770, and lightly
- * tested on other ads7846 devices (OSK/Mistral, Lubbock).
- * Support for ads7843 and ads7845 has only been stubbed in.
- *
- * IRQ handling needs a workaround because of a shortcoming in handling
- * edge triggered IRQs on some platforms like the OMAP1/2. These
- * platforms don't handle the ARM lazy IRQ disabling properly, thus we
- * have to maintain our own SW IRQ disabled status. This should be
- * removed as soon as the affected platform's IRQ handling is fixed.
- *
- * app note sbaa036 talks in more detail about accurate sampling...
- * that ought to help in situations like LCDs inducing noise (which
- * can also be helped by using synch signals) and more generally.
- * This driver tries to utilize the measures described in the app
- * note. The strength of filtering can be set in the board-* specific
- * files.
- */
- #define TS_POLL_DELAY (1 * 1000000) /* ns delay before the first sample */
- #define TS_POLL_PERIOD (5 * 1000000) /* ns delay between samples */
- /* this driver doesn't aim at the peak continuous sample rate */
- #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
- struct ts_event {
- /* For portability, we can't read 12 bit values using SPI (which
- * would make the controller deliver them as native byteorder u16
- * with msbs zeroed). Instead, we read them as two 8-bit values,
- * *** WHICH NEED BYTESWAPPING *** and range adjustment.
- */
- u16 x;
- u16 y;
- u16 z1, z2;
- int ignore;
- };
- struct ads7846 {
- struct input_dev *input;
- 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;
- u16 pressure_max;
- u8 read_x, read_y, read_z1, read_z2, pwrdown;
- u16 dummy; /* for the pwrdown read */
- struct ts_event tc;
- struct spi_transfer xfer[10];
- struct spi_message msg[5];
- struct spi_message *last_msg;
- int msg_idx;
- int read_cnt;
- int read_rep;
- int last_read;
- u16 debounce_max;
- u16 debounce_tol;
- u16 debounce_rep;
- spinlock_t lock;
- struct hrtimer timer;
- unsigned pendown:1; /* P: lock */
- unsigned pending:1; /* P: lock */
- // FIXME remove "irq_disabled"
- unsigned irq_disabled:1; /* P: lock */
- unsigned disabled:1;
- int (*filter)(void *data, int data_idx, int *val);
- void *filter_data;
- void (*filter_cleanup)(void *data);
- int (*get_pendown_state)(void);
- };
- /* leave chip selected when we're done, for quicker re-select? */
- #if 0
- #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
- #else
- #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
- #endif
- /*--------------------------------------------------------------------------*/
- /* The ADS7846 has touchscreen and other sensors.
- * Earlier ads784x chips are somewhat compatible.
- */
- #define ADS_START (1 << 7)
- #define ADS_A2A1A0_d_y (1 << 4) /* differential */
- #define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
- #define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
- #define ADS_A2A1A0_d_x (5 << 4) /* differential */
- #define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
- #define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
- #define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
- #define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
- #define ADS_8_BIT (1 << 3)
- #define ADS_12_BIT (0 << 3)
- #define ADS_SER (1 << 2) /* non-differential */
- #define ADS_DFR (0 << 2) /* differential */
- #define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */
- #define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
- #define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
- #define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
- #define MAX_12BIT ((1<<12)-1)
- /* leave ADC powered up (disables penirq) between differential samples */
- #define READ_12BIT_DFR(x, adc, vref) (ADS_START | ADS_A2A1A0_d_ ## x \
- | ADS_12_BIT | ADS_DFR | \
- (adc ? ADS_PD10_ADC_ON : 0) | (vref ? ADS_PD10_REF_ON : 0))
- #define READ_Y(vref) (READ_12BIT_DFR(y, 1, vref))
- #define READ_Z1(vref) (READ_12BIT_DFR(z1, 1, vref))
- #define READ_Z2(vref) (READ_12BIT_DFR(z2, 1, vref))
- #define READ_X(vref) (READ_12BIT_DFR(x, 1, vref))
- #define PWRDOWN (READ_12BIT_DFR(y, 0, 0)) /* LAST */
- /* single-ended samples need to first power up reference voltage;
- * we leave both ADC and VREF powered
- */
- #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
- | ADS_12_BIT | ADS_SER)
- #define REF_ON (READ_12BIT_DFR(x, 1, 1))
- #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
- /*--------------------------------------------------------------------------*/
- /*
- * 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;
- u8 command;
- u8 ref_off;
- u16 scratch;
- __be16 sample;
- struct spi_message msg;
- struct spi_transfer xfer[6];
- };
- static void ads7846_enable(struct ads7846 *ts);
- static void ads7846_disable(struct ads7846 *ts);
- static int device_suspended(struct device *dev)
- {
- struct ads7846 *ts = dev_get_drvdata(dev);
- return dev->power.power_state.event != PM_EVENT_ON || ts->disabled;
- }
- static int ads7846_read12_ser(struct device *dev, unsigned command)
- {
- struct spi_device *spi = to_spi_device(dev);
- struct ads7846 *ts = dev_get_drvdata(dev);
- struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
- int status;
- int sample;
- int use_internal;
- if (!req)
- return -ENOMEM;
- spi_message_init(&req->msg);
- /* FIXME boards with ads7846 might use external vref instead ... */
- use_internal = (ts->model == 7846);
- /* 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 ... */
- /* 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);
- 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);
- status = spi_sync(spi, &req->msg);
- ts->irq_disabled = 0;
- enable_irq(spi->irq);
- if (req->msg.status)
- status = req->msg.status;
- /* on-wire is a must-ignore bit, a BE12 value, then padding */
- sample = be16_to_cpu(req->sample);
- sample = sample >> 3;
- sample &= 0x0fff;
- kfree(req);
- return status ? status : sample;
- }
- #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(var) | ADS_PD10_ALL_ON); \
- if (v < 0) \
- return v; \
- return sprintf(buf, "%u\n", adjust(ts, v)); \
- } \
- static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
- /* 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);
- return ts->pendown;
- }
- static ssize_t ads7846_pen_down_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return sprintf(buf, "%u\n", is_pen_down(dev));
- }
- static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
- static ssize_t ads7846_disable_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct ads7846 *ts = dev_get_drvdata(dev);
- return sprintf(buf, "%u\n", ts->disabled);
- }
- static ssize_t ads7846_disable_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
- {
- struct ads7846 *ts = dev_get_drvdata(dev);
- char *endp;
- int i;
- i = simple_strtoul(buf, &endp, 10);
- spin_lock_irq(&ts->lock);
- if (i)
- ads7846_disable(ts);
- else
- ads7846_enable(ts);
- spin_unlock_irq(&ts->lock);
- return count;
- }
- static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
- static struct attribute *ads784x_attributes[] = {
- &dev_attr_pen_down.attr,
- &dev_attr_disable.attr,
- NULL,
- };
- static struct attribute_group ads784x_attr_group = {
- .attrs = ads784x_attributes,
- };
- /*--------------------------------------------------------------------------*/
- /*
- * PENIRQ only kicks the timer. The timer only reissues the SPI transfer,
- * to retrieve touchscreen status.
- *
- * The SPI transfer completion callback does the real work. It reports
- * touchscreen events and reactivates the timer (or IRQ) as appropriate.
- */
- static void ads7846_rx(void *ads)
- {
- struct ads7846 *ts = ads;
- unsigned Rt;
- u16 x, y, z1, z2;
- /* ads7846_rx_val() did in-place conversion (including byteswap) from
- * on-the-wire format as part of debouncing to get stable readings.
- */
- x = ts->tc.x;
- y = ts->tc.y;
- z1 = ts->tc.z1;
- z2 = ts->tc.z2;
- /* range filtering */
- if (x == MAX_12BIT)
- x = 0;
- if (likely(x && z1)) {
- /* compute touch pressure resistance using equation #2 */
- Rt = z2;
- Rt -= z1;
- Rt *= x;
- Rt *= ts->x_plate_ohms;
- Rt /= z1;
- Rt = (Rt + 2047) >> 12;
- } else
- Rt = 0;
- /* Sample found inconsistent by debouncing or pressure is beyond
- * the maximum. Don't report it to user space, repeat at least
- * once more the measurement
- */
- if (ts->tc.ignore || Rt > ts->pressure_max) {
- #ifdef VERBOSE
- pr_debug("%s: ignored %d pressure %d\n",
- ts->spi->dev.bus_id, ts->tc.ignore, Rt);
- #endif
- hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
- HRTIMER_MODE_REL);
- return;
- }
- /* NOTE: We can't rely on the pressure to determine the pen down
- * state, even this controller has a pressure sensor. The pressure
- * value can fluctuate for quite a while after lifting the pen and
- * in some cases may not even settle at the expected value.
- *
- * The only safe way to check for the pen up condition is in the
- * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
- */
- if (Rt) {
- struct input_dev *input = ts->input;
- if (!ts->pendown) {
- input_report_key(input, BTN_TOUCH, 1);
- ts->pendown = 1;
- #ifdef VERBOSE
- dev_dbg(&ts->spi->dev, "DOWN\n");
- #endif
- }
- input_report_abs(input, ABS_X, x);
- input_report_abs(input, ABS_Y, y);
- input_report_abs(input, ABS_PRESSURE, Rt);
- input_sync(input);
- #ifdef VERBOSE
- dev_dbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt);
- #endif
- }
- hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
- HRTIMER_MODE_REL);
- }
- static int ads7846_debounce(void *ads, int data_idx, int *val)
- {
- struct ads7846 *ts = ads;
- if (!ts->read_cnt || (abs(ts->last_read - *val) > ts->debounce_tol)) {
- /* Start over collecting consistent readings. */
- ts->read_rep = 0;
- /* Repeat it, if this was the first read or the read
- * wasn't consistent enough. */
- if (ts->read_cnt < ts->debounce_max) {
- ts->last_read = *val;
- ts->read_cnt++;
- return ADS7846_FILTER_REPEAT;
- } else {
- /* Maximum number of debouncing reached and still
- * not enough number of consistent readings. Abort
- * the whole sample, repeat it in the next sampling
- * period.
- */
- ts->read_cnt = 0;
- return ADS7846_FILTER_IGNORE;
- }
- } else {
- if (++ts->read_rep > ts->debounce_rep) {
- /* Got a good reading for this coordinate,
- * go for the next one. */
- ts->read_cnt = 0;
- ts->read_rep = 0;
- return ADS7846_FILTER_OK;
- } else {
- /* Read more values that are consistent. */
- ts->read_cnt++;
- return ADS7846_FILTER_REPEAT;
- }
- }
- }
- static int ads7846_no_filter(void *ads, int data_idx, int *val)
- {
- return ADS7846_FILTER_OK;
- }
- static void ads7846_rx_val(void *ads)
- {
- struct ads7846 *ts = ads;
- struct spi_message *m;
- struct spi_transfer *t;
- u16 *rx_val;
- int val;
- int action;
- int status;
- m = &ts->msg[ts->msg_idx];
- t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
- rx_val = t->rx_buf;
- /* adjust: on-wire is a must-ignore bit, a BE12 value, then padding;
- * built from two 8 bit values written msb-first.
- */
- val = be16_to_cpu(*rx_val) >> 3;
- action = ts->filter(ts->filter_data, ts->msg_idx, &val);
- switch (action) {
- case ADS7846_FILTER_REPEAT:
- break;
- case ADS7846_FILTER_IGNORE:
- ts->tc.ignore = 1;
- /* Last message will contain ads7846_rx() as the
- * completion function.
- */
- m = ts->last_msg;
- break;
- case ADS7846_FILTER_OK:
- *rx_val = val;
- ts->tc.ignore = 0;
- m = &ts->msg[++ts->msg_idx];
- break;
- default:
- BUG();
- }
- status = spi_async(ts->spi, m);
- if (status)
- dev_err(&ts->spi->dev, "spi_async --> %d\n",
- status);
- }
- static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
- {
- struct ads7846 *ts = container_of(handle, struct ads7846, timer);
- int status = 0;
- spin_lock_irq(&ts->lock);
- if (unlikely(!ts->get_pendown_state() ||
- device_suspended(&ts->spi->dev))) {
- if (ts->pendown) {
- struct input_dev *input = ts->input;
- input_report_key(input, BTN_TOUCH, 0);
- input_report_abs(input, ABS_PRESSURE, 0);
- input_sync(input);
- ts->pendown = 0;
- #ifdef VERBOSE
- dev_dbg(&ts->spi->dev, "UP\n");
- #endif
- }
- /* measurement cycle ended */
- if (!device_suspended(&ts->spi->dev)) {
- ts->irq_disabled = 0;
- enable_irq(ts->spi->irq);
- }
- ts->pending = 0;
- } else {
- /* pen is still down, continue with the measurement */
- ts->msg_idx = 0;
- status = spi_async(ts->spi, &ts->msg[0]);
- if (status)
- dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
- }
- spin_unlock_irq(&ts->lock);
- return HRTIMER_NORESTART;
- }
- static irqreturn_t ads7846_irq(int irq, void *handle)
- {
- struct ads7846 *ts = handle;
- unsigned long flags;
- spin_lock_irqsave(&ts->lock, flags);
- if (likely(ts->get_pendown_state())) {
- if (!ts->irq_disabled) {
- /* The ARM do_simple_IRQ() dispatcher doesn't act
- * like the other dispatchers: it will report IRQs
- * even after they've been disabled. We work around
- * that here. (The "generic irq" framework may help...)
- */
- ts->irq_disabled = 1;
- disable_irq(ts->spi->irq);
- ts->pending = 1;
- hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
- HRTIMER_MODE_REL);
- }
- }
- spin_unlock_irqrestore(&ts->lock, flags);
- return IRQ_HANDLED;
- }
- /*--------------------------------------------------------------------------*/
- /* Must be called with ts->lock held */
- static void ads7846_disable(struct ads7846 *ts)
- {
- if (ts->disabled)
- return;
- ts->disabled = 1;
- /* are we waiting for IRQ, or polling? */
- if (!ts->pending) {
- ts->irq_disabled = 1;
- disable_irq(ts->spi->irq);
- } else {
- /* the timer will run at least once more, and
- * leave everything in a clean state, IRQ disabled
- */
- while (ts->pending) {
- spin_unlock_irq(&ts->lock);
- msleep(1);
- spin_lock_irq(&ts->lock);
- }
- }
- /* we know the chip's in lowpower mode since we always
- * leave it that way after every request
- */
- }
- /* Must be called with ts->lock held */
- static void ads7846_enable(struct ads7846 *ts)
- {
- if (!ts->disabled)
- return;
- ts->disabled = 0;
- ts->irq_disabled = 0;
- enable_irq(ts->spi->irq);
- }
- static int ads7846_suspend(struct spi_device *spi, pm_message_t message)
- {
- struct ads7846 *ts = dev_get_drvdata(&spi->dev);
- spin_lock_irq(&ts->lock);
- spi->dev.power.power_state = message;
- ads7846_disable(ts);
- spin_unlock_irq(&ts->lock);
- return 0;
- }
- static int ads7846_resume(struct spi_device *spi)
- {
- struct ads7846 *ts = dev_get_drvdata(&spi->dev);
- spin_lock_irq(&ts->lock);
- spi->dev.power.power_state = PMSG_ON;
- ads7846_enable(ts);
- spin_unlock_irq(&ts->lock);
- return 0;
- }
- static int __devinit ads7846_probe(struct spi_device *spi)
- {
- struct ads7846 *ts;
- struct input_dev *input_dev;
- struct ads7846_platform_data *pdata = spi->dev.platform_data;
- struct spi_message *m;
- struct spi_transfer *x;
- int vref;
- int err;
- if (!spi->irq) {
- dev_dbg(&spi->dev, "no IRQ?\n");
- return -ENODEV;
- }
- if (!pdata) {
- dev_dbg(&spi->dev, "no platform data?\n");
- return -ENODEV;
- }
- /* don't exceed max specified sample rate */
- if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
- dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
- (spi->max_speed_hz/SAMPLE_BITS)/1000);
- return -EINVAL;
- }
- /* REVISIT when the irq can be triggered active-low, or if for some
- * reason the touchscreen isn't hooked up, we don't need to access
- * the pendown state.
- */
- if (pdata->get_pendown_state == NULL) {
- dev_dbg(&spi->dev, "no get_pendown_state function?\n");
- return -EINVAL;
- }
- /* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
- * that even if the hardware can do that, the SPI controller driver
- * may not. So we stick to very-portable 8 bit words, both RX and TX.
- */
- spi->bits_per_word = 8;
- spi->mode = SPI_MODE_1;
- err = spi_setup(spi);
- if (err < 0)
- return err;
- ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
- input_dev = input_allocate_device();
- if (!ts || !input_dev) {
- err = -ENOMEM;
- goto err_free_mem;
- }
- dev_set_drvdata(&spi->dev, ts);
- spi->dev.power.power_state = PMSG_ON;
- ts->spi = spi;
- ts->input = input_dev;
- hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
- ts->timer.function = ads7846_timer;
- spin_lock_init(&ts->lock);
- ts->model = pdata->model ? : 7846;
- ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
- ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
- ts->pressure_max = pdata->pressure_max ? : ~0;
- if (pdata->filter != NULL) {
- if (pdata->filter_init != NULL) {
- err = pdata->filter_init(pdata, &ts->filter_data);
- if (err < 0)
- goto err_free_mem;
- }
- ts->filter = pdata->filter;
- ts->filter_cleanup = pdata->filter_cleanup;
- } else if (pdata->debounce_max) {
- ts->debounce_max = pdata->debounce_max;
- if (ts->debounce_max < 2)
- ts->debounce_max = 2;
- ts->debounce_tol = pdata->debounce_tol;
- ts->debounce_rep = pdata->debounce_rep;
- ts->filter = ads7846_debounce;
- ts->filter_data = ts;
- } else
- ts->filter = ads7846_no_filter;
- ts->get_pendown_state = pdata->get_pendown_state;
- snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
- input_dev->name = "ADS784x Touchscreen";
- input_dev->phys = ts->phys;
- input_dev->cdev.dev = &spi->dev;
- input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
- input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
- input_set_abs_params(input_dev, ABS_X,
- pdata->x_min ? : 0,
- pdata->x_max ? : MAX_12BIT,
- 0, 0);
- input_set_abs_params(input_dev, ABS_Y,
- pdata->y_min ? : 0,
- pdata->y_max ? : MAX_12BIT,
- 0, 0);
- input_set_abs_params(input_dev, ABS_PRESSURE,
- pdata->pressure_min, pdata->pressure_max, 0, 0);
- vref = pdata->keep_vref_on;
- /* set up the transfers to read touchscreen state; this assumes we
- * use formula #2 for pressure, not #3.
- */
- m = &ts->msg[0];
- x = ts->xfer;
- spi_message_init(m);
- /* y- still on; turn on only y+ (and ADC) */
- ts->read_y = READ_Y(vref);
- x->tx_buf = &ts->read_y;
- x->len = 1;
- spi_message_add_tail(x, m);
- x++;
- x->rx_buf = &ts->tc.y;
- x->len = 2;
- spi_message_add_tail(x, m);
- m->complete = ads7846_rx_val;
- m->context = ts;
- m++;
- spi_message_init(m);
- /* turn y- off, x+ on, then leave in lowpower */
- x++;
- ts->read_x = READ_X(vref);
- x->tx_buf = &ts->read_x;
- x->len = 1;
- spi_message_add_tail(x, m);
- x++;
- x->rx_buf = &ts->tc.x;
- x->len = 2;
- spi_message_add_tail(x, m);
- m->complete = ads7846_rx_val;
- m->context = ts;
- /* turn y+ off, x- on; we'll use formula #2 */
- if (ts->model == 7846) {
- m++;
- spi_message_init(m);
- x++;
- ts->read_z1 = READ_Z1(vref);
- x->tx_buf = &ts->read_z1;
- x->len = 1;
- spi_message_add_tail(x, m);
- x++;
- x->rx_buf = &ts->tc.z1;
- x->len = 2;
- spi_message_add_tail(x, m);
- m->complete = ads7846_rx_val;
- m->context = ts;
- m++;
- spi_message_init(m);
- x++;
- ts->read_z2 = READ_Z2(vref);
- x->tx_buf = &ts->read_z2;
- x->len = 1;
- spi_message_add_tail(x, m);
- x++;
- x->rx_buf = &ts->tc.z2;
- x->len = 2;
- spi_message_add_tail(x, m);
- m->complete = ads7846_rx_val;
- m->context = ts;
- }
- /* power down */
- m++;
- spi_message_init(m);
- x++;
- ts->pwrdown = PWRDOWN;
- x->tx_buf = &ts->pwrdown;
- x->len = 1;
- spi_message_add_tail(x, m);
- x++;
- x->rx_buf = &ts->dummy;
- x->len = 2;
- CS_CHANGE(*x);
- spi_message_add_tail(x, m);
- m->complete = ads7846_rx;
- m->context = ts;
- ts->last_msg = m;
- if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING,
- spi->dev.driver->name, ts)) {
- dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
- err = -EBUSY;
- 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 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);
- err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
- if (err)
- goto err_remove_hwmon;
- err = input_register_device(input_dev);
- if (err)
- goto err_remove_attr_group;
- return 0;
- err_remove_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:
- if (ts->filter_cleanup)
- ts->filter_cleanup(ts->filter_data);
- err_free_mem:
- input_free_device(input_dev);
- kfree(ts);
- return err;
- }
- 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, &ads784x_attr_group);
- free_irq(ts->spi->irq, ts);
- /* suspend left the IRQ disabled */
- enable_irq(ts->spi->irq);
- if (ts->filter_cleanup)
- ts->filter_cleanup(ts->filter_data);
- kfree(ts);
- dev_dbg(&spi->dev, "unregistered touchscreen\n");
- return 0;
- }
- static struct spi_driver ads7846_driver = {
- .driver = {
- .name = "ads7846",
- .bus = &spi_bus_type,
- .owner = THIS_MODULE,
- },
- .probe = ads7846_probe,
- .remove = __devexit_p(ads7846_remove),
- .suspend = ads7846_suspend,
- .resume = ads7846_resume,
- };
- static int __init ads7846_init(void)
- {
- /* grr, board-specific init should stay out of drivers!! */
- #ifdef CONFIG_ARCH_OMAP
- if (machine_is_omap_osk()) {
- /* GPIO4 = PENIRQ; GPIO6 = BUSY */
- omap_request_gpio(4);
- omap_set_gpio_direction(4, 1);
- omap_request_gpio(6);
- omap_set_gpio_direction(6, 1);
- }
- // also TI 1510 Innovator, bitbanging through FPGA
- // also Nokia 770
- // also Palm Tungsten T2
- #endif
- // PXA:
- // also Dell Axim X50
- // also HP iPaq H191x/H192x/H415x/H435x
- // also Intel Lubbock (additional to UCB1400; as temperature sensor)
- // also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky)
- // Atmel at91sam9261-EK uses ads7843
- // also various AMD Au1x00 devel boards
- return spi_register_driver(&ads7846_driver);
- }
- module_init(ads7846_init);
- static void __exit ads7846_exit(void)
- {
- spi_unregister_driver(&ads7846_driver);
- #ifdef CONFIG_ARCH_OMAP
- if (machine_is_omap_osk()) {
- omap_free_gpio(4);
- omap_free_gpio(6);
- }
- #endif
- }
- module_exit(ads7846_exit);
- MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
- MODULE_LICENSE("GPL");
|