diff options
Diffstat (limited to 'drivers/input/touchscreen/ads7846.c')
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 4d13db13b9e5..67264c5b49cb 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -30,7 +30,7 @@ #include <linux/spi/ads7846.h> #include <linux/regulator/consumer.h> #include <linux/module.h> -#include <asm/unaligned.h> +#include <linux/unaligned.h> /* * This code has been heavily tested on a Nokia 770, and lightly @@ -138,6 +138,7 @@ struct ads7846 { void *filter_data; int (*get_pendown_state)(void); struct gpio_desc *gpio_pendown; + struct gpio_desc *gpio_hsync; void (*wait_for_sync)(void); }; @@ -330,7 +331,7 @@ struct ser_req { u8 ref_off; u16 scratch; struct spi_message msg; - struct spi_transfer xfer[6]; + struct spi_transfer xfer[8]; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -404,9 +405,19 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) 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); + /* clear the command register */ + req->scratch = 0; + req->xfer[6].tx_buf = &req->scratch; + req->xfer[6].len = 1; + spi_message_add_tail(&req->xfer[6], &req->msg); + + req->xfer[7].rx_buf = &req->scratch; + req->xfer[7].len = 2; + CS_CHANGE(req->xfer[7]); + spi_message_add_tail(&req->xfer[7], &req->msg); + mutex_lock(&ts->lock); ads7846_stop(ts); status = spi_sync(spi, &req->msg); @@ -634,10 +645,6 @@ ATTRIBUTE_GROUPS(ads784x); /*--------------------------------------------------------------------------*/ -static void null_wait_for_sync(void) -{ -} - static int ads7846_debounce_filter(void *ads, int data_idx, int *val) { struct ads7846 *ts = ads; @@ -790,6 +797,28 @@ static int ads7846_filter(struct ads7846 *ts) return 0; } +static void ads7846_wait_for_hsync(struct ads7846 *ts) +{ + if (ts->wait_for_sync) { + ts->wait_for_sync(); + return; + } + + if (!ts->gpio_hsync) + return; + + /* + * Wait for HSYNC to assert the line should be flagged + * as active low so here we are waiting for it to assert + */ + while (!gpiod_get_value(ts->gpio_hsync)) + cpu_relax(); + + /* Then we wait for it do de-assert */ + while (gpiod_get_value(ts->gpio_hsync)) + cpu_relax(); +} + static void ads7846_read_state(struct ads7846 *ts) { struct ads7846_packet *packet = ts->packet; @@ -800,12 +829,12 @@ static void ads7846_read_state(struct ads7846 *ts) packet->last_cmd_idx = 0; while (true) { - ts->wait_for_sync(); + ads7846_wait_for_hsync(ts); m = &ts->msg[msg_idx]; error = spi_sync(ts->spi, m); if (error) { - dev_err(&ts->spi->dev, "spi_sync --> %d\n", error); + dev_err_ratelimited(&ts->spi->dev, "spi_sync --> %d\n", error); packet->ignore = true; return; } @@ -992,7 +1021,7 @@ static int ads7846_setup_pendown(struct spi_device *spi, if (pdata->get_pendown_state) { ts->get_pendown_state = pdata->get_pendown_state; } else { - ts->gpio_pendown = gpiod_get(&spi->dev, "pendown", GPIOD_IN); + ts->gpio_pendown = devm_gpiod_get(&spi->dev, "pendown", GPIOD_IN); if (IS_ERR(ts->gpio_pendown)) { dev_err(&spi->dev, "failed to request pendown GPIO\n"); return PTR_ERR(ts->gpio_pendown); @@ -1268,7 +1297,11 @@ static int ads7846_probe(struct spi_device *spi) ts->penirq_recheck_delay_usecs = pdata->penirq_recheck_delay_usecs; - ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; + ts->wait_for_sync = pdata->wait_for_sync; + + ts->gpio_hsync = devm_gpiod_get_optional(dev, "ti,hsync", GPIOD_IN); + if (IS_ERR(ts->gpio_hsync)) + return PTR_ERR(ts->gpio_hsync); snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev)); snprintf(ts->name, sizeof(ts->name), "ADS%d Touchscreen", ts->model); |