diff options
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 192 |
1 files changed, 62 insertions, 130 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 1e3fc62d0ea8..95e89f675ad5 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -62,19 +62,26 @@ /* this driver doesn't aim at the peak continuous sample rate */ #define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */) -struct ts_event { +struct ads7846_buf { + u8 cmd; /* - * 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. + * This union is a temporary hack. The driver does an in-place + * endianness conversion. This will be cleaned up in the next + * patch. */ - u16 x; - u16 y; - u16 z1, z2; - bool ignore; - u8 x_buf[3]; - u8 y_buf[3]; + union { + __be16 data_be16; + u16 data; + }; +} __packed; + + +struct ts_event { + bool ignore; + struct ads7846_buf x; + struct ads7846_buf y; + struct ads7846_buf z1; + struct ads7846_buf z2; }; /* @@ -83,11 +90,12 @@ struct ts_event { * 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 ts_event tc; + struct ads7846_buf read_x_cmd; + struct ads7846_buf read_y_cmd; + struct ads7846_buf read_z1_cmd; + struct ads7846_buf read_z2_cmd; + struct ads7846_buf pwrdown_cmd; }; struct ads7846 { @@ -686,16 +694,9 @@ static int ads7846_get_value(struct ads7846 *ts, struct spi_message *m) int value; struct spi_transfer *t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list); + struct ads7846_buf *buf = t->rx_buf; - if (ts->model == 7845) { - value = be16_to_cpup((__be16 *)&(((char *)t->rx_buf)[1])); - } else { - /* - * adjust: on-wire is a must-ignore bit, a BE12 value, then - * padding; built from two 8 bit values written msb-first. - */ - value = be16_to_cpup((__be16 *)t->rx_buf); - } + value = be16_to_cpup(&buf->data_be16); /* enforce ADC output is 12 bits width */ return (value >> 3) & 0xfff; @@ -705,8 +706,9 @@ 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); + struct ads7846_buf *buf = t->rx_buf; - *(u16 *)t->rx_buf = val; + buf->data = val; } static void ads7846_read_state(struct ads7846 *ts) @@ -774,16 +776,14 @@ static void ads7846_report_state(struct ads7846 *ts) * from on-the-wire format as part of debouncing to get stable * readings. */ + x = packet->tc.x.data; + y = packet->tc.y.data; 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; + z1 = packet->tc.z1.data; + z2 = packet->tc.z2.data; } /* range filtering */ @@ -1000,26 +1000,11 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, 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); - } + packet->read_y_cmd.cmd = READ_Y(vref); + x->tx_buf = &packet->read_y_cmd; + x->rx_buf = &packet->tc.y; + x->len = 3; + spi_message_add_tail(x, m); /* * The first sample after switching drivers can be low quality; @@ -1029,15 +1014,11 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, if (pdata->settle_delay_usecs) { x->delay.value = pdata->settle_delay_usecs; x->delay.unit = SPI_DELAY_UNIT_USECS; - x++; - x->tx_buf = &packet->read_y; - x->len = 1; - spi_message_add_tail(x, m); - x++; + x->tx_buf = &packet->read_y_cmd; x->rx_buf = &packet->tc.y; - x->len = 2; + x->len = 3; spi_message_add_tail(x, m); } @@ -1046,28 +1027,13 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, 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); - } + /* turn y- off, x+ on, then leave in lowpower */ + x++; + packet->read_x_cmd.cmd = READ_X(vref); + x->tx_buf = &packet->read_x_cmd; + x->rx_buf = &packet->tc.x; + x->len = 3; + spi_message_add_tail(x, m); /* ... maybe discard first sample ... */ if (pdata->settle_delay_usecs) { @@ -1075,13 +1041,9 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, x->delay.unit = SPI_DELAY_UNIT_USECS; x++; - x->tx_buf = &packet->read_x; - x->len = 1; - spi_message_add_tail(x, m); - - x++; + x->tx_buf = &packet->read_x_cmd; x->rx_buf = &packet->tc.x; - x->len = 2; + x->len = 3; spi_message_add_tail(x, m); } @@ -1093,14 +1055,10 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, 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++; + packet->read_z1_cmd.cmd = READ_Z1(vref); + x->tx_buf = &packet->read_z1_cmd; x->rx_buf = &packet->tc.z1; - x->len = 2; + x->len = 3; spi_message_add_tail(x, m); /* ... maybe discard first sample ... */ @@ -1109,13 +1067,9 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, x->delay.unit = SPI_DELAY_UNIT_USECS; x++; - x->tx_buf = &packet->read_z1; - x->len = 1; - spi_message_add_tail(x, m); - - x++; + x->tx_buf = &packet->read_z1_cmd; x->rx_buf = &packet->tc.z1; - x->len = 2; + x->len = 3; spi_message_add_tail(x, m); } @@ -1125,14 +1079,10 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, 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++; + packet->read_z2_cmd.cmd = READ_Z2(vref); + x->tx_buf = &packet->read_z2_cmd; x->rx_buf = &packet->tc.z2; - x->len = 2; + x->len = 3; spi_message_add_tail(x, m); /* ... maybe discard first sample ... */ @@ -1141,13 +1091,9 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, x->delay.unit = SPI_DELAY_UNIT_USECS; x++; - x->tx_buf = &packet->read_z2; - x->len = 1; - spi_message_add_tail(x, m); - - x++; + x->tx_buf = &packet->read_z2_cmd; x->rx_buf = &packet->tc.z2; - x->len = 2; + x->len = 3; spi_message_add_tail(x, m); } } @@ -1158,24 +1104,10 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts, 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; - } + x++; + packet->pwrdown_cmd.cmd = PWRDOWN; + x->tx_buf = &packet->pwrdown_cmd; + x->len = 3; CS_CHANGE(*x); spi_message_add_tail(x, m); |