diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/input/touchscreen/ads7846.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/input/touchscreen/ads7846.c | 1440 |
1 files changed, 0 insertions, 1440 deletions
diff --git a/ANDROID_3.4.5/drivers/input/touchscreen/ads7846.c b/ANDROID_3.4.5/drivers/input/touchscreen/ads7846.c deleted file mode 100644 index f02028ec..00000000 --- a/ANDROID_3.4.5/drivers/input/touchscreen/ads7846.c +++ /dev/null @@ -1,1440 +0,0 @@ -/* - * 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/types.h> -#include <linux/hwmon.h> -#include <linux/init.h> -#include <linux/err.h> -#include <linux/sched.h> -#include <linux/delay.h> -#include <linux/input.h> -#include <linux/interrupt.h> -#include <linux/slab.h> -#include <linux/pm.h> -#include <linux/gpio.h> -#include <linux/spi/spi.h> -#include <linux/spi/ads7846.h> -#include <linux/regulator/consumer.h> -#include <linux/module.h> -#include <asm/irq.h> - -/* - * This code has been heavily tested on a Nokia 770, and lightly - * tested on other ads7846 devices (OSK/Mistral, Lubbock, Spitz). - * TSC2046 is just newer ads7846 silicon. - * Support for ads7843 tested on Atmel at91sam926x-EK. - * Support for ads7845 has only been stubbed in. - * Support for Analog Devices AD7873 and AD7843 tested. - * - * 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 /* ms delay before the first sample */ -#define TS_POLL_PERIOD 5 /* ms 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 byte order 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; - bool ignore; - u8 x_buf[3]; - u8 y_buf[3]; -}; - -/* - * We allocate this separately to avoid cache line sharing issues when - * driver is used with DMA-based SPI controllers (like atmel_spi) on - * systems where main memory is not DMA-coherent (most non-x86 boards). - */ -struct ads7846_packet { - u8 read_x, read_y, read_z1, read_z2, pwrdown; - u16 dummy; /* for the pwrdown read */ - struct ts_event tc; - /* for ads7845 with mpc5121 psc spi we use 3-byte buffers */ - u8 read_x_cmd[3], read_y_cmd[3], pwrdown_cmd[3]; -}; - -struct ads7846 { - struct input_dev *input; - char phys[32]; - char name[32]; - - struct spi_device *spi; - struct regulator *reg; - -#if defined(CONFIG_HWMON) || defined(CONFIG_HWMON_MODULE) - struct attribute_group *attr_group; - struct device *hwmon; -#endif - - u16 model; - u16 vref_mv; - u16 vref_delay_usecs; - u16 x_plate_ohms; - u16 pressure_max; - - bool swap_xy; - bool use_internal; - - struct ads7846_packet *packet; - - struct spi_transfer xfer[18]; - struct spi_message msg[5]; - int msg_count; - wait_queue_head_t wait; - - bool pendown; - - int read_cnt; - int read_rep; - int last_read; - - u16 debounce_max; - u16 debounce_tol; - u16 debounce_rep; - - u16 penirq_recheck_delay_usecs; - - struct mutex lock; - bool stopped; /* P: lock */ - bool disabled; /* P: lock */ - bool suspended; /* P: lock */ - - int (*filter)(void *data, int data_idx, int *val); - void *filter_data; - void (*filter_cleanup)(void *data); - int (*get_pendown_state)(void); - int gpio_pendown; - - void (*wait_for_sync)(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) /* low power 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)) - -/* Must be called with ts->lock held */ -static void ads7846_stop(struct ads7846 *ts) -{ - if (!ts->disabled && !ts->suspended) { - /* Signal IRQ thread to stop polling and disable the handler. */ - ts->stopped = true; - mb(); - wake_up(&ts->wait); - disable_irq(ts->spi->irq); - } -} - -/* Must be called with ts->lock held */ -static void ads7846_restart(struct ads7846 *ts) -{ - if (!ts->disabled && !ts->suspended) { - /* Tell IRQ thread that it may poll the device. */ - ts->stopped = false; - mb(); - enable_irq(ts->spi->irq); - } -} - -/* Must be called with ts->lock held */ -static void __ads7846_disable(struct ads7846 *ts) -{ - ads7846_stop(ts); - regulator_disable(ts->reg); - - /* - * We know the chip's in low power 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) -{ - regulator_enable(ts->reg); - ads7846_restart(ts); -} - -static void ads7846_disable(struct ads7846 *ts) -{ - mutex_lock(&ts->lock); - - if (!ts->disabled) { - - if (!ts->suspended) - __ads7846_disable(ts); - - ts->disabled = true; - } - - mutex_unlock(&ts->lock); -} - -static void ads7846_enable(struct ads7846 *ts) -{ - mutex_lock(&ts->lock); - - if (ts->disabled) { - - ts->disabled = false; - - if (!ts->suspended) - __ads7846_enable(ts); - } - - mutex_unlock(&ts->lock); -} - -/*--------------------------------------------------------------------------*/ - -/* - * 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. - */ - -struct ser_req { - u8 ref_on; - u8 command; - u8 ref_off; - u16 scratch; - struct spi_message msg; - struct spi_transfer xfer[6]; - /* - * DMA (thus cache coherency maintenance) requires the - * transfer buffers to live in their own cache lines. - */ - __be16 sample ____cacheline_aligned; -}; - -struct ads7845_ser_req { - u8 command[3]; - struct spi_message msg; - struct spi_transfer xfer[2]; - /* - * DMA (thus cache coherency maintenance) requires the - * transfer buffers to live in their own cache lines. - */ - u8 sample[3] ____cacheline_aligned; -}; - -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; - int status; - - req = kzalloc(sizeof *req, GFP_KERNEL); - if (!req) - return -ENOMEM; - - spi_message_init(&req->msg); - - /* maybe turn on internal vREF, and let it settle */ - if (ts->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); - - /* Enable reference voltage */ - command |= ADS_PD10_REF_ON; - } - - /* Enable ADC in every case */ - command |= ADS_PD10_ADC_ON; - - /* 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 ... */ - - /* converter in low power mode & enable PENIRQ */ - req->ref_off = PWRDOWN; - 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); - - mutex_lock(&ts->lock); - ads7846_stop(ts); - status = spi_sync(spi, &req->msg); - ads7846_restart(ts); - mutex_unlock(&ts->lock); - - if (status == 0) { - /* on-wire is a must-ignore bit, a BE12 value, then padding */ - status = be16_to_cpu(req->sample); - status = status >> 3; - status &= 0x0fff; - } - - kfree(req); - return status; -} - -static int ads7845_read12_ser(struct device *dev, unsigned command) -{ - struct spi_device *spi = to_spi_device(dev); - struct ads7846 *ts = dev_get_drvdata(dev); - struct ads7845_ser_req *req; - int status; - - req = kzalloc(sizeof *req, GFP_KERNEL); - if (!req) - return -ENOMEM; - - spi_message_init(&req->msg); - - req->command[0] = (u8) command; - req->xfer[0].tx_buf = req->command; - req->xfer[0].rx_buf = req->sample; - req->xfer[0].len = 3; - spi_message_add_tail(&req->xfer[0], &req->msg); - - mutex_lock(&ts->lock); - ads7846_stop(ts); - status = spi_sync(spi, &req->msg); - ads7846_restart(ts); - mutex_unlock(&ts->lock); - - if (status == 0) { - /* BE12 value, then padding */ - status = be16_to_cpu(*((u16 *)&req->sample[1])); - status = status >> 3; - status &= 0x0fff; - } - - kfree(req); - return status; -} - -#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)); \ - 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 Celsius. - * 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 *= ts->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 device *hwmon; - int err; - - /* hwmon sensors need a reference voltage */ - switch (ts->model) { - case 7846: - if (!ts->vref_mv) { - dev_dbg(&spi->dev, "assuming 2.5V internal vREF\n"); - ts->vref_mv = 2500; - ts->use_internal = true; - } - break; - case 7845: - case 7843: - if (!ts->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 ssize_t ads7846_pen_down_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct ads7846 *ts = dev_get_drvdata(dev); - - return sprintf(buf, "%u\n", ts->pendown); -} - -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); - unsigned int i; - int err; - - err = kstrtouint(buf, 10, &i); - if (err) - return err; - - if (i) - ads7846_disable(ts); - else - ads7846_enable(ts); - - 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, -}; - -/*--------------------------------------------------------------------------*/ - -static int get_pendown_state(struct ads7846 *ts) -{ - if (ts->get_pendown_state) - return ts->get_pendown_state(); - - return !gpio_get_value(ts->gpio_pendown); -} - -static void null_wait_for_sync(void) -{ -} - -static int ads7846_debounce_filter(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 int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) -{ - struct spi_transfer *t = - list_entry(m->transfers.prev, struct spi_transfer, transfer_list); - - if (ts->model == 7845) { - return be16_to_cpup((__be16 *)&(((char*)t->rx_buf)[1])) >> 3; - } else { - /* - * adjust: on-wire is a must-ignore bit, a BE12 value, then - * padding; built from two 8 bit values written msb-first. - */ - return be16_to_cpup((__be16 *)t->rx_buf) >> 3; - } -} - -static void ads7846_update_value(struct spi_message *m, int val) -{ - struct spi_transfer *t = - list_entry(m->transfers.prev, struct spi_transfer, transfer_list); - - *(u16 *)t->rx_buf = val; -} - -static void ads7846_read_state(struct ads7846 *ts) -{ - struct ads7846_packet *packet = ts->packet; - struct spi_message *m; - int msg_idx = 0; - int val; - int action; - int error; - - while (msg_idx < ts->msg_count) { - - ts->wait_for_sync(); - - m = &ts->msg[msg_idx]; - error = spi_sync(ts->spi, m); - if (error) { - dev_err(&ts->spi->dev, "spi_async --> %d\n", error); - packet->tc.ignore = true; - return; - } - - /* - * Last message is power down request, no need to convert - * or filter the value. - */ - if (msg_idx < ts->msg_count - 1) { - - val = ads7846_get_value(ts, m); - - action = ts->filter(ts->filter_data, msg_idx, &val); - switch (action) { - case ADS7846_FILTER_REPEAT: - continue; - - case ADS7846_FILTER_IGNORE: - packet->tc.ignore = true; - msg_idx = ts->msg_count - 1; - continue; - - case ADS7846_FILTER_OK: - ads7846_update_value(m, val); - packet->tc.ignore = false; - msg_idx++; - break; - - default: - BUG(); - } - } else { - msg_idx++; - } - } -} - -static void ads7846_report_state(struct ads7846 *ts) -{ - struct ads7846_packet *packet = ts->packet; - unsigned int Rt; - u16 x, y, z1, z2; - - /* - * ads7846_get_value() does in-place conversion (including byte swap) - * from on-the-wire format as part of debouncing to get stable - * readings. - */ - if (ts->model == 7845) { - x = *(u16 *)packet->tc.x_buf; - y = *(u16 *)packet->tc.y_buf; - z1 = 0; - z2 = 0; - } else { - x = packet->tc.x; - y = packet->tc.y; - z1 = packet->tc.z1; - z2 = packet->tc.z2; - } - - /* range filtering */ - if (x == MAX_12BIT) - x = 0; - - if (ts->model == 7843) { - Rt = ts->pressure_max / 2; - } else if (ts->model == 7845) { - if (get_pendown_state(ts)) - Rt = ts->pressure_max / 2; - else - Rt = 0; - dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt); - } else 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 (packet->tc.ignore || Rt > ts->pressure_max) { - dev_vdbg(&ts->spi->dev, "ignored %d pressure %d\n", - packet->tc.ignore, Rt); - return; - } - - /* - * Maybe check the pendown state before reporting. This discards - * false readings when the pen is lifted. - */ - if (ts->penirq_recheck_delay_usecs) { - udelay(ts->penirq_recheck_delay_usecs); - if (!get_pendown_state(ts)) - Rt = 0; - } - - /* - * 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->swap_xy) - swap(x, y); - - if (!ts->pendown) { - input_report_key(input, BTN_TOUCH, 1); - ts->pendown = true; - dev_vdbg(&ts->spi->dev, "DOWN\n"); - } - - input_report_abs(input, ABS_X, x); - input_report_abs(input, ABS_Y, y); - input_report_abs(input, ABS_PRESSURE, ts->pressure_max - Rt); - - input_sync(input); - dev_vdbg(&ts->spi->dev, "%4d/%4d/%4d\n", x, y, Rt); - } -} - -static irqreturn_t ads7846_hard_irq(int irq, void *handle) -{ - struct ads7846 *ts = handle; - - return get_pendown_state(ts) ? IRQ_WAKE_THREAD : IRQ_HANDLED; -} - - -static irqreturn_t ads7846_irq(int irq, void *handle) -{ - struct ads7846 *ts = handle; - - /* Start with a small delay before checking pendown state */ - msleep(TS_POLL_DELAY); - - while (!ts->stopped && get_pendown_state(ts)) { - - /* pen is down, continue with the measurement */ - ads7846_read_state(ts); - - if (!ts->stopped) - ads7846_report_state(ts); - - wait_event_timeout(ts->wait, ts->stopped, - msecs_to_jiffies(TS_POLL_PERIOD)); - } - - 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 = false; - dev_vdbg(&ts->spi->dev, "UP\n"); - } - - return IRQ_HANDLED; -} - -#ifdef CONFIG_PM_SLEEP -static int ads7846_suspend(struct device *dev) -{ - struct ads7846 *ts = dev_get_drvdata(dev); - - mutex_lock(&ts->lock); - - if (!ts->suspended) { - - if (!ts->disabled) - __ads7846_disable(ts); - - if (device_may_wakeup(&ts->spi->dev)) - enable_irq_wake(ts->spi->irq); - - ts->suspended = true; - } - - mutex_unlock(&ts->lock); - - return 0; -} - -static int ads7846_resume(struct device *dev) -{ - struct ads7846 *ts = dev_get_drvdata(dev); - - mutex_lock(&ts->lock); - - if (ts->suspended) { - - ts->suspended = false; - - if (device_may_wakeup(&ts->spi->dev)) - disable_irq_wake(ts->spi->irq); - - if (!ts->disabled) - __ads7846_enable(ts); - } - - mutex_unlock(&ts->lock); - - return 0; -} -#endif - -static SIMPLE_DEV_PM_OPS(ads7846_pm, ads7846_suspend, ads7846_resume); - -static int __devinit ads7846_setup_pendown(struct spi_device *spi, struct ads7846 *ts) -{ - struct ads7846_platform_data *pdata = spi->dev.platform_data; - int err; - - /* - * 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) { - ts->get_pendown_state = pdata->get_pendown_state; - } else if (gpio_is_valid(pdata->gpio_pendown)) { - - err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN, - "ads7846_pendown"); - if (err) { - dev_err(&spi->dev, - "failed to request/setup pendown GPIO%d: %d\n", - pdata->gpio_pendown, err); - return err; - } - - ts->gpio_pendown = pdata->gpio_pendown; - - } else { - dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n"); - return -EINVAL; - } - - return 0; -} - -/* - * Set up the transfers to read touchscreen state; this assumes we - * use formula #2 for pressure, not #3. - */ -static void __devinit ads7846_setup_spi_msg(struct ads7846 *ts, - const struct ads7846_platform_data *pdata) -{ - struct spi_message *m = &ts->msg[0]; - struct spi_transfer *x = ts->xfer; - struct ads7846_packet *packet = ts->packet; - int vref = pdata->keep_vref_on; - - if (ts->model == 7873) { - /* - * The AD7873 is almost identical to the ADS7846 - * keep VREF off during differential/ratiometric - * conversion modes. - */ - ts->model = 7846; - vref = 0; - } - - ts->msg_count = 1; - spi_message_init(m); - m->context = ts; - - if (ts->model == 7845) { - packet->read_y_cmd[0] = READ_Y(vref); - packet->read_y_cmd[1] = 0; - packet->read_y_cmd[2] = 0; - x->tx_buf = &packet->read_y_cmd[0]; - x->rx_buf = &packet->tc.y_buf[0]; - x->len = 3; - spi_message_add_tail(x, m); - } else { - /* y- still on; turn on only y+ (and ADC) */ - packet->read_y = READ_Y(vref); - x->tx_buf = &packet->read_y; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.y; - x->len = 2; - spi_message_add_tail(x, m); - } - - /* - * The first sample after switching drivers can be low quality; - * optionally discard it, using a second one after the signals - * have had enough time to stabilize. - */ - if (pdata->settle_delay_usecs) { - x->delay_usecs = pdata->settle_delay_usecs; - - x++; - x->tx_buf = &packet->read_y; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.y; - x->len = 2; - spi_message_add_tail(x, m); - } - - ts->msg_count++; - m++; - spi_message_init(m); - m->context = ts; - - if (ts->model == 7845) { - x++; - packet->read_x_cmd[0] = READ_X(vref); - packet->read_x_cmd[1] = 0; - packet->read_x_cmd[2] = 0; - x->tx_buf = &packet->read_x_cmd[0]; - x->rx_buf = &packet->tc.x_buf[0]; - x->len = 3; - spi_message_add_tail(x, m); - } else { - /* turn y- off, x+ on, then leave in lowpower */ - x++; - packet->read_x = READ_X(vref); - x->tx_buf = &packet->read_x; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.x; - x->len = 2; - spi_message_add_tail(x, m); - } - - /* ... maybe discard first sample ... */ - if (pdata->settle_delay_usecs) { - x->delay_usecs = pdata->settle_delay_usecs; - - x++; - x->tx_buf = &packet->read_x; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.x; - x->len = 2; - spi_message_add_tail(x, m); - } - - /* turn y+ off, x- on; we'll use formula #2 */ - if (ts->model == 7846) { - ts->msg_count++; - m++; - spi_message_init(m); - m->context = ts; - - x++; - packet->read_z1 = READ_Z1(vref); - x->tx_buf = &packet->read_z1; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.z1; - x->len = 2; - spi_message_add_tail(x, m); - - /* ... maybe discard first sample ... */ - if (pdata->settle_delay_usecs) { - x->delay_usecs = pdata->settle_delay_usecs; - - x++; - x->tx_buf = &packet->read_z1; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.z1; - x->len = 2; - spi_message_add_tail(x, m); - } - - ts->msg_count++; - m++; - spi_message_init(m); - m->context = ts; - - x++; - packet->read_z2 = READ_Z2(vref); - x->tx_buf = &packet->read_z2; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.z2; - x->len = 2; - spi_message_add_tail(x, m); - - /* ... maybe discard first sample ... */ - if (pdata->settle_delay_usecs) { - x->delay_usecs = pdata->settle_delay_usecs; - - x++; - x->tx_buf = &packet->read_z2; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->tc.z2; - x->len = 2; - spi_message_add_tail(x, m); - } - } - - /* power down */ - ts->msg_count++; - m++; - spi_message_init(m); - m->context = ts; - - if (ts->model == 7845) { - x++; - packet->pwrdown_cmd[0] = PWRDOWN; - packet->pwrdown_cmd[1] = 0; - packet->pwrdown_cmd[2] = 0; - x->tx_buf = &packet->pwrdown_cmd[0]; - x->len = 3; - } else { - x++; - packet->pwrdown = PWRDOWN; - x->tx_buf = &packet->pwrdown; - x->len = 1; - spi_message_add_tail(x, m); - - x++; - x->rx_buf = &packet->dummy; - x->len = 2; - } - - CS_CHANGE(*x); - spi_message_add_tail(x, m); -} - -static int __devinit ads7846_probe(struct spi_device *spi) -{ - struct ads7846 *ts; - struct ads7846_packet *packet; - struct input_dev *input_dev; - struct ads7846_platform_data *pdata = spi->dev.platform_data; - unsigned long irq_flags; - 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; - } - - /* We'd set TX word size 8 bits and RX word size 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_0; - err = spi_setup(spi); - if (err < 0) - return err; - - ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); - packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); - input_dev = input_allocate_device(); - if (!ts || !packet || !input_dev) { - err = -ENOMEM; - goto err_free_mem; - } - - dev_set_drvdata(&spi->dev, ts); - - ts->packet = packet; - ts->spi = spi; - ts->input = input_dev; - ts->vref_mv = pdata->vref_mv; - ts->swap_xy = pdata->swap_xy; - - mutex_init(&ts->lock); - init_waitqueue_head(&ts->wait); - - 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_filter; - ts->filter_data = ts; - } else { - ts->filter = ads7846_no_filter; - } - - err = ads7846_setup_pendown(spi, ts); - if (err) - goto err_cleanup_filter; - - if (pdata->penirq_recheck_delay_usecs) - ts->penirq_recheck_delay_usecs = - pdata->penirq_recheck_delay_usecs; - - ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; - - snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); - snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); - - input_dev->name = ts->name; - input_dev->phys = ts->phys; - input_dev->dev.parent = &spi->dev; - - input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); - input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(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); - - ads7846_setup_spi_msg(ts, pdata); - - ts->reg = regulator_get(&spi->dev, "vcc"); - if (IS_ERR(ts->reg)) { - err = PTR_ERR(ts->reg); - dev_err(&spi->dev, "unable to get regulator: %d\n", err); - goto err_free_gpio; - } - - err = regulator_enable(ts->reg); - if (err) { - dev_err(&spi->dev, "unable to enable regulator: %d\n", err); - goto err_put_regulator; - } - - irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING; - irq_flags |= IRQF_ONESHOT; - - err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq, - irq_flags, spi->dev.driver->name, ts); - if (err && !pdata->irq_flags) { - dev_info(&spi->dev, - "trying pin change workaround on irq %d\n", spi->irq); - irq_flags |= IRQF_TRIGGER_RISING; - err = request_threaded_irq(spi->irq, - ads7846_hard_irq, ads7846_irq, - irq_flags, spi->dev.driver->name, ts); - } - - if (err) { - dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); - goto err_disable_regulator; - } - - 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. - */ - if (ts->model == 7845) - ads7845_read12_ser(&spi->dev, PWRDOWN); - else - (void) ads7846_read12_ser(&spi->dev, READ_12BIT_SER(vaux)); - - 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; - - device_init_wakeup(&spi->dev, pdata->wakeup); - - 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_disable_regulator: - regulator_disable(ts->reg); - err_put_regulator: - regulator_put(ts->reg); - err_free_gpio: - if (!ts->get_pendown_state) - gpio_free(ts->gpio_pendown); - err_cleanup_filter: - if (ts->filter_cleanup) - ts->filter_cleanup(ts->filter_data); - err_free_mem: - input_free_device(input_dev); - kfree(packet); - kfree(ts); - return err; -} - -static int __devexit ads7846_remove(struct spi_device *spi) -{ - struct ads7846 *ts = dev_get_drvdata(&spi->dev); - - device_init_wakeup(&spi->dev, false); - - sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group); - - ads7846_disable(ts); - free_irq(ts->spi->irq, ts); - - input_unregister_device(ts->input); - - ads784x_hwmon_unregister(spi, ts); - - regulator_disable(ts->reg); - regulator_put(ts->reg); - - if (!ts->get_pendown_state) { - /* - * If we are not using specialized pendown method we must - * have been relying on gpio we set up ourselves. - */ - gpio_free(ts->gpio_pendown); - } - - if (ts->filter_cleanup) - ts->filter_cleanup(ts->filter_data); - - kfree(ts->packet); - kfree(ts); - - dev_dbg(&spi->dev, "unregistered touchscreen\n"); - - return 0; -} - -static struct spi_driver ads7846_driver = { - .driver = { - .name = "ads7846", - .owner = THIS_MODULE, - .pm = &ads7846_pm, - }, - .probe = ads7846_probe, - .remove = __devexit_p(ads7846_remove), -}; - -module_spi_driver(ads7846_driver); - -MODULE_DESCRIPTION("ADS7846 TouchScreen Driver"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("spi:ads7846"); |