diff options
Diffstat (limited to 'drivers/input/touchscreen')
-rw-r--r-- | drivers/input/touchscreen/ads7846.c | 147 |
1 files changed, 91 insertions, 56 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index b45a45c..8c12a97 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -48,10 +48,13 @@ #define TS_POLL_PERIOD msecs_to_jiffies(10) +/* 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-byte values, + * with msbs zeroed). Instead, we read them as two 8-bit values, * which need byteswapping then range adjustment. */ __be16 x; @@ -60,7 +63,7 @@ struct ts_event { }; struct ads7846 { - struct input_dev input; + struct input_dev *input; char phys[32]; struct spi_device *spi; @@ -68,6 +71,7 @@ struct ads7846 { u16 vref_delay_usecs; u16 x_plate_ohms; + u8 read_x, read_y, read_z1, read_z2; struct ts_event tc; struct spi_transfer xfer[8]; @@ -117,10 +121,10 @@ struct ads7846 { #define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \ | ADS_12_BIT | ADS_DFR) -static const u8 read_y = READ_12BIT_DFR(y) | ADS_PD10_ADC_ON; -static const u8 read_z1 = READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON; -static const u8 read_z2 = READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON; -static const u8 read_x = READ_12BIT_DFR(x) | ADS_PD10_PDOWN; /* LAST */ +#define READ_Y (READ_12BIT_DFR(y) | ADS_PD10_ADC_ON) +#define READ_Z1 (READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON) +#define READ_Z2 (READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON) +#define READ_X (READ_12BIT_DFR(x) | ADS_PD10_PDOWN) /* LAST */ /* single-ended samples need to first power up reference voltage; * we leave both ADC and VREF powered @@ -128,8 +132,8 @@ static const u8 read_x = READ_12BIT_DFR(x) | ADS_PD10_PDOWN; /* LAST */ #define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \ | ADS_12_BIT | ADS_SER) -static const u8 ref_on = READ_12BIT_DFR(x) | ADS_PD10_ALL_ON; -static const u8 ref_off = READ_12BIT_DFR(y) | ADS_PD10_PDOWN; +#define REF_ON (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON) +#define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) /*--------------------------------------------------------------------------*/ @@ -138,7 +142,9 @@ static const u8 ref_off = READ_12BIT_DFR(y) | ADS_PD10_PDOWN; */ struct ser_req { + u8 ref_on; u8 command; + u8 ref_off; u16 scratch; __be16 sample; struct spi_message msg; @@ -152,7 +158,7 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) struct ser_req *req = kzalloc(sizeof *req, SLAB_KERNEL); int status; int sample; - int i; + int i; if (!req) return -ENOMEM; @@ -160,7 +166,8 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) INIT_LIST_HEAD(&req->msg.transfers); /* activate reference, so it has time to settle; */ - req->xfer[0].tx_buf = &ref_on; + req->ref_on = REF_ON; + req->xfer[0].tx_buf = &req->ref_on; req->xfer[0].len = 1; req->xfer[1].rx_buf = &req->scratch; req->xfer[1].len = 2; @@ -182,7 +189,8 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) /* REVISIT: take a few more samples, and compare ... */ /* turn off reference */ - req->xfer[4].tx_buf = &ref_off; + req->ref_off = REF_OFF; + req->xfer[4].tx_buf = &req->ref_off; req->xfer[4].len = 1; req->xfer[5].rx_buf = &req->scratch; req->xfer[5].len = 2; @@ -236,11 +244,12 @@ SHOW(vbatt) static void ads7846_rx(void *ads) { - struct ads7846 *ts = ads; - unsigned Rt; - unsigned sync = 0; - u16 x, y, z1, z2; - unsigned long flags; + struct ads7846 *ts = ads; + struct input_dev *input_dev = ts->input; + unsigned Rt; + unsigned sync = 0; + u16 x, y, z1, z2; + unsigned long flags; /* adjust: 12 bit samples (left aligned), built from * two 8 bit values writen msb-first. @@ -276,21 +285,21 @@ static void ads7846_rx(void *ads) * won't notice that, even if nPENIRQ never fires ... */ if (!ts->pendown && Rt != 0) { - input_report_key(&ts->input, BTN_TOUCH, 1); + input_report_key(input_dev, BTN_TOUCH, 1); sync = 1; } else if (ts->pendown && Rt == 0) { - input_report_key(&ts->input, BTN_TOUCH, 0); + input_report_key(input_dev, BTN_TOUCH, 0); sync = 1; } if (Rt) { - input_report_abs(&ts->input, ABS_X, x); - input_report_abs(&ts->input, ABS_Y, y); - input_report_abs(&ts->input, ABS_PRESSURE, Rt); + input_report_abs(input_dev, ABS_X, x); + input_report_abs(input_dev, ABS_Y, y); + input_report_abs(input_dev, ABS_PRESSURE, Rt); sync = 1; } if (sync) - input_sync(&ts->input); + input_sync(input_dev); #ifdef VERBOSE if (Rt || ts->pendown) @@ -396,9 +405,10 @@ static int ads7846_resume(struct spi_device *spi) 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_transfer *x; - int i; + int err; if (!spi->irq) { dev_dbg(&spi->dev, "no IRQ?\n"); @@ -411,9 +421,9 @@ static int __devinit ads7846_probe(struct spi_device *spi) } /* don't exceed max specified sample rate */ - if (spi->max_speed_hz > (125000 * 16)) { + if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { dev_dbg(&spi->dev, "f(sample) %d KHz?\n", - (spi->max_speed_hz/16)/1000); + (spi->max_speed_hz/SAMPLE_BITS)/1000); return -EINVAL; } @@ -423,13 +433,18 @@ static int __devinit ads7846_probe(struct spi_device *spi) * to discard the four garbage LSBs. */ - if (!(ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL))) - return -ENOMEM; + 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; - spi->dev.power.power_state = PMSG_ON; + ts->input = input_dev; init_timer(&ts->timer); ts->timer.data = (unsigned long) ts; @@ -439,70 +454,80 @@ static int __devinit ads7846_probe(struct spi_device *spi) ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; - init_input_dev(&ts->input); + snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id); - ts->input.dev = &spi->dev; - ts->input.name = "ADS784x Touchscreen"; - snprintf(ts->phys, sizeof ts->phys, "%s/input0", spi->dev.bus_id); - ts->input.phys = ts->phys; + input_dev->name = "ADS784x Touchscreen"; + input_dev->phys = ts->phys; + input_dev->cdev.dev = &spi->dev; - ts->input.evbit[0] = BIT(EV_KEY) | BIT(EV_ABS); - ts->input.keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH); - input_set_abs_params(&ts->input, ABS_X, + 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(&ts->input, ABS_Y, + input_set_abs_params(input_dev, ABS_Y, pdata->y_min ? : 0, pdata->y_max ? : MAX_12BIT, 0, 0); - input_set_abs_params(&ts->input, ABS_PRESSURE, + input_set_abs_params(input_dev, ABS_PRESSURE, pdata->pressure_min, pdata->pressure_max, 0, 0); - input_register_device(&ts->input); - /* set up the transfers to read touchscreen state; this assumes we * use formula #2 for pressure, not #3. */ + INIT_LIST_HEAD(&ts->msg.transfers); x = ts->xfer; /* y- still on; turn on only y+ (and ADC) */ - x->tx_buf = &read_y; + ts->read_y = READ_Y; + x->tx_buf = &ts->read_y; x->len = 1; + spi_message_add_tail(x, &ts->msg); + x++; x->rx_buf = &ts->tc.y; x->len = 2; - x++; + spi_message_add_tail(x, &ts->msg); /* turn y+ off, x- on; we'll use formula #2 */ if (ts->model == 7846) { - x->tx_buf = &read_z1; + x++; + ts->read_z1 = READ_Z1; + x->tx_buf = &ts->read_z1; x->len = 1; + spi_message_add_tail(x, &ts->msg); + x++; x->rx_buf = &ts->tc.z1; x->len = 2; - x++; + spi_message_add_tail(x, &ts->msg); - x->tx_buf = &read_z2; + x++; + ts->read_z2 = READ_Z2; + x->tx_buf = &ts->read_z2; x->len = 1; + spi_message_add_tail(x, &ts->msg); + x++; x->rx_buf = &ts->tc.z2; x->len = 2; - x++; + spi_message_add_tail(x, &ts->msg); } /* turn y- off, x+ on, then leave in lowpower */ - x->tx_buf = &read_x; + x++; + ts->read_x = READ_X; + x->tx_buf = &ts->read_x; x->len = 1; + spi_message_add_tail(x, &ts->msg); + x++; x->rx_buf = &ts->tc.x; x->len = 2; - x++; - - CS_CHANGE(x[-1]); + CS_CHANGE(*x); + spi_message_add_tail(x, &ts->msg); - for (i = 0; i < x - ts->xfer; i++) - spi_message_add_tail(&ts->xfer[i], &ts->msg); ts->msg.complete = ads7846_rx; ts->msg.context = ts; @@ -510,9 +535,8 @@ static int __devinit ads7846_probe(struct spi_device *spi) SA_SAMPLE_RANDOM | SA_TRIGGER_FALLING, spi->dev.bus_id, ts)) { dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq); - input_unregister_device(&ts->input); - kfree(ts); - return -EBUSY; + err = -EBUSY; + goto err_free_mem; } dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq); @@ -534,7 +558,18 @@ static int __devinit ads7846_probe(struct spi_device *spi) device_create_file(&spi->dev, &dev_attr_vbatt); device_create_file(&spi->dev, &dev_attr_vaux); + err = input_register_device(input_dev); + if (err) + goto err_free_irq; + return 0; + + err_free_irq: + free_irq(spi->irq, ts); + err_free_mem: + input_free_device(input_dev); + kfree(ts); + return err; } static int __devexit ads7846_remove(struct spi_device *spi) @@ -554,7 +589,7 @@ static int __devexit ads7846_remove(struct spi_device *spi) device_remove_file(&spi->dev, &dev_attr_vbatt); device_remove_file(&spi->dev, &dev_attr_vaux); - input_unregister_device(&ts->input); + input_unregister_device(ts->input); kfree(ts); dev_dbg(&spi->dev, "unregistered touchscreen\n"); |