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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [input/] [touchscreen/] [ads7846.c] - Blame information for rev 62

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/*
 * 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).
 * TSC2046 is just newer ads7846 silicon.
 * Support for ads7843 tested on Atmel at91sam926x-EK.
 * Support for 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 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[18];
        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;
 
        u16                     penirq_recheck_delay_usecs;
 
        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 ... */
 
        /* 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);
 
        ts->irq_disabled = 1;
        disable_irq(spi->irq);
        status = spi_sync(spi, &req->msg);
        ts->irq_disabled = 0;
        enable_irq(spi->irq);
 
        if (status == 0) {
                /* 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 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;
 
        if (ts->model == 7843)
                Rt = ts->pressure_max / 2;
 
        /* 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;
        }
 
        /* 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 (!ts->get_pendown_state())
                        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->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_0;
        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;
 
        if (pdata->penirq_recheck_delay_usecs)
                ts->penirq_recheck_delay_usecs =
                                pdata->penirq_recheck_delay_usecs;
 
        snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
 
        input_dev->name = "ADS784x Touchscreen";
        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);
 
        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);
 
        /* 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 = &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);
 
        /* ... maybe discard first sample ... */
        if (pdata->settle_delay_usecs) {
                x->delay_usecs = pdata->settle_delay_usecs;
 
                x++;
                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);
 
                /* ... maybe discard first sample ... */
                if (pdata->settle_delay_usecs) {
                        x->delay_usecs = pdata->settle_delay_usecs;
 
                        x++;
                        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);
 
                /* ... maybe discard first sample ... */
                if (pdata->settle_delay_usecs) {
                        x->delay_usecs = pdata->settle_delay_usecs;
 
                        x++;
                        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");
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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [input/] [touchscreen/] [ads7846.c] - Blame information for rev 62

Line No.	Rev	Author	Line
1	62	marcus.erl	`/*`
2			`* ADS7846 based touchscreen and sensor driver`
3			`*`
4			`* Copyright (c) 2005 David Brownell`
5			`* Copyright (c) 2006 Nokia Corporation`
6			`* Various changes: Imre Deak <imre.deak@nokia.com>`
7			`*`
8			`* Using code from:`
9			`* - corgi_ts.c`
10			`* Copyright (C) 2004-2005 Richard Purdie`
11			`* - omap_ts.[hc], ads7846.h, ts_osk.c`
12			`* Copyright (C) 2002 MontaVista Software`
13			`* Copyright (C) 2004 Texas Instruments`
14			`* Copyright (C) 2005 Dirk Behme`
15			`*`
16			`* This program is free software; you can redistribute it and/or modify`
17			`* it under the terms of the GNU General Public License version 2 as`
18			`* published by the Free Software Foundation.`
19			`*/`
20			`#include <linux/hwmon.h>`
21			`#include <linux/init.h>`
22			`#include <linux/err.h>`
23			`#include <linux/delay.h>`
24			`#include <linux/input.h>`
25			`#include <linux/interrupt.h>`
26			`#include <linux/slab.h>`
27			`#include <linux/spi/spi.h>`
28			`#include <linux/spi/ads7846.h>`
29			`#include <asm/irq.h>`
30
31			`#ifdef CONFIG_ARM`
32			`#include <asm/mach-types.h>`
33			`#ifdef CONFIG_ARCH_OMAP`
34			`#include <asm/arch/gpio.h>`
35			`#endif`
36			`#endif`
37
38
39			`/*`
40			`* This code has been heavily tested on a Nokia 770, and lightly`