diff options
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 87 |
1 files changed, 51 insertions, 36 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 6020a7dcce33..b9b7fc6ff1eb 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -69,6 +69,17 @@ struct ts_event { int ignore; }; +/* + * 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; +}; + struct ads7846 { struct input_dev *input; char phys[32]; @@ -86,9 +97,7 @@ struct ads7846 { 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 ads7846_packet *packet; struct spi_transfer xfer[18]; struct spi_message msg[5]; @@ -513,16 +522,17 @@ static int get_pendown_state(struct ads7846 *ts) static void ads7846_rx(void *ads) { struct ads7846 *ts = ads; + struct ads7846_packet *packet = ts->packet; 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; + x = packet->tc.x; + y = packet->tc.y; + z1 = packet->tc.z1; + z2 = packet->tc.z2; /* range filtering */ if (x == MAX_12BIT) @@ -546,10 +556,10 @@ static void ads7846_rx(void *ads) * the maximum. Don't report it to user space, repeat at least * once more the measurement */ - if (ts->tc.ignore || Rt > ts->pressure_max) { + if (packet->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); + ts->spi->dev.bus_id, packet->tc.ignore, Rt); #endif hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), HRTIMER_MODE_REL); @@ -642,6 +652,7 @@ static int ads7846_no_filter(void *ads, int data_idx, int *val) static void ads7846_rx_val(void *ads) { struct ads7846 *ts = ads; + struct ads7846_packet *packet = ts->packet; struct spi_message *m; struct spi_transfer *t; int val; @@ -661,7 +672,7 @@ static void ads7846_rx_val(void *ads) case ADS7846_FILTER_REPEAT: break; case ADS7846_FILTER_IGNORE: - ts->tc.ignore = 1; + packet->tc.ignore = 1; /* Last message will contain ads7846_rx() as the * completion function. */ @@ -669,7 +680,7 @@ static void ads7846_rx_val(void *ads) break; case ADS7846_FILTER_OK: *(u16 *)t->rx_buf = val; - ts->tc.ignore = 0; + packet->tc.ignore = 0; m = &ts->msg[++ts->msg_idx]; break; default: @@ -774,7 +785,6 @@ static void ads7846_disable(struct ads7846 *ts) /* 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 */ @@ -850,6 +860,7 @@ static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts) 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; struct spi_message *m; @@ -885,14 +896,16 @@ static int __devinit ads7846_probe(struct spi_device *spi) return err; ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL); + packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL); input_dev = input_allocate_device(); - if (!ts || !input_dev) { + 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; @@ -964,13 +977,13 @@ static int __devinit ads7846_probe(struct spi_device *spi) 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; + 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 = &ts->tc.y; + x->rx_buf = &packet->tc.y; x->len = 2; spi_message_add_tail(x, m); @@ -982,12 +995,12 @@ static int __devinit ads7846_probe(struct spi_device *spi) x->delay_usecs = pdata->settle_delay_usecs; x++; - x->tx_buf = &ts->read_y; + x->tx_buf = &packet->read_y; x->len = 1; spi_message_add_tail(x, m); x++; - x->rx_buf = &ts->tc.y; + x->rx_buf = &packet->tc.y; x->len = 2; spi_message_add_tail(x, m); } @@ -1000,13 +1013,13 @@ static int __devinit ads7846_probe(struct spi_device *spi) /* turn y- off, x+ on, then leave in lowpower */ x++; - ts->read_x = READ_X(vref); - x->tx_buf = &ts->read_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 = &ts->tc.x; + x->rx_buf = &packet->tc.x; x->len = 2; spi_message_add_tail(x, m); @@ -1015,12 +1028,12 @@ static int __devinit ads7846_probe(struct spi_device *spi) x->delay_usecs = pdata->settle_delay_usecs; x++; - x->tx_buf = &ts->read_x; + x->tx_buf = &packet->read_x; x->len = 1; spi_message_add_tail(x, m); x++; - x->rx_buf = &ts->tc.x; + x->rx_buf = &packet->tc.x; x->len = 2; spi_message_add_tail(x, m); } @@ -1034,13 +1047,13 @@ static int __devinit ads7846_probe(struct spi_device *spi) spi_message_init(m); x++; - ts->read_z1 = READ_Z1(vref); - x->tx_buf = &ts->read_z1; + 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 = &ts->tc.z1; + x->rx_buf = &packet->tc.z1; x->len = 2; spi_message_add_tail(x, m); @@ -1049,12 +1062,12 @@ static int __devinit ads7846_probe(struct spi_device *spi) x->delay_usecs = pdata->settle_delay_usecs; x++; - x->tx_buf = &ts->read_z1; + x->tx_buf = &packet->read_z1; x->len = 1; spi_message_add_tail(x, m); x++; - x->rx_buf = &ts->tc.z1; + x->rx_buf = &packet->tc.z1; x->len = 2; spi_message_add_tail(x, m); } @@ -1066,13 +1079,13 @@ static int __devinit ads7846_probe(struct spi_device *spi) spi_message_init(m); x++; - ts->read_z2 = READ_Z2(vref); - x->tx_buf = &ts->read_z2; + 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 = &ts->tc.z2; + x->rx_buf = &packet->tc.z2; x->len = 2; spi_message_add_tail(x, m); @@ -1081,12 +1094,12 @@ static int __devinit ads7846_probe(struct spi_device *spi) x->delay_usecs = pdata->settle_delay_usecs; x++; - x->tx_buf = &ts->read_z2; + x->tx_buf = &packet->read_z2; x->len = 1; spi_message_add_tail(x, m); x++; - x->rx_buf = &ts->tc.z2; + x->rx_buf = &packet->tc.z2; x->len = 2; spi_message_add_tail(x, m); } @@ -1100,13 +1113,13 @@ static int __devinit ads7846_probe(struct spi_device *spi) spi_message_init(m); x++; - ts->pwrdown = PWRDOWN; - x->tx_buf = &ts->pwrdown; + packet->pwrdown = PWRDOWN; + x->tx_buf = &packet->pwrdown; x->len = 1; spi_message_add_tail(x, m); x++; - x->rx_buf = &ts->dummy; + x->rx_buf = &packet->dummy; x->len = 2; CS_CHANGE(*x); spi_message_add_tail(x, m); @@ -1159,6 +1172,7 @@ static int __devinit ads7846_probe(struct spi_device *spi) ts->filter_cleanup(ts->filter_data); err_free_mem: input_free_device(input_dev); + kfree(packet); kfree(ts); return err; } @@ -1184,6 +1198,7 @@ static int __devexit ads7846_remove(struct spi_device *spi) if (ts->filter_cleanup) ts->filter_cleanup(ts->filter_data); + kfree(ts->packet); kfree(ts); dev_dbg(&spi->dev, "unregistered touchscreen\n"); |
