This patch adds device tree bindings to the ads7846 driver, and documents the required and optional binding properties.
Successfully tested on an OMAP3 board. Signed-off-by: Daniel Mack <[email protected]> --- .../devicetree/bindings/input/ads7846.txt | 86 ++++++++++ drivers/input/touchscreen/ads7846.c | 189 ++++++++++++++++----- 2 files changed, 231 insertions(+), 44 deletions(-) create mode 100644 Documentation/devicetree/bindings/input/ads7846.txt diff --git a/Documentation/devicetree/bindings/input/ads7846.txt b/Documentation/devicetree/bindings/input/ads7846.txt new file mode 100644 index 0000000..ac564a1 --- /dev/null +++ b/Documentation/devicetree/bindings/input/ads7846.txt @@ -0,0 +1,86 @@ +Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046 +SPI driven touch screen controllers. + +The node for this driver must be a child node of a SPI controller, hence +all mandatory properties described in + + Documentation/devicetree/bindings/spi/spi-bus.txt + +must be specified.. + +Additional required properties: + + compatible Must be one of the following, depending on the + model: + "ti,tsc2046" + "ti,ads7843" + "ti,ads7845" + "ti,ads7846" + "ti,ads7873" + + interrupt-parent + interrupts An interrupt node describing the IRQ line the chip's + !PENIRQ pin is connected to. + vcc-supply A regulator node for the supply voltage. + + +Optional properties: + + ti,vref-delay-usecs vref supply delay in usecs, 0 for + external vref + ti,vref-mv The VREF voltage, in millivolts. + ti,keep-vref-on set to keep vref on for differential + measurements as well. + ti,swap-xy swap x and y axis + ti,settle-delay-usec Settling time of the analog signals; + a function of Vcc and the capacitance + on the X/Y drivers. If set to non-zero, + two samples are taken with settle_delay + us apart, and the second one is used. + ~150 uSec with 0.01uF caps. + ti,penirq-recheck-delay-usecs If set to non-zero, after samples are + taken this delay is applied and penirq + is rechecked, to help avoid false + events. This value is affected by the + material used to build the touch layer. + ti,x-plate-ohms Resistance of the X-plate, in Ohms. + ti,y-plate-ohms Resistance of the Y-plate, in Ohms. + ti,x-min Minimum value on the X axis. + ti,y-min Minimum value on the Y axis. + ti,x-max Maximum value on the X axis. + ti,y-max Minimum value on the Y axis. + ti,pressure-min Minimum reported pressure value (threshold). + ti,pressure-max Maximum reported pressure value. + ti,debounce-max Max number of additional readings per sample. + ti,debounce-tol Tolerance used for filtering. + ti,debounce-rep Additional consecutive good readings + required after the first two. + ti,pendown-gpio-debounce Platform specific debounce time for the + pendown-gpio. + pendown-gpio GPIO handle describing the pin the !PENIRQ + line is connected to. + linux,wakeup use any event on touchscreen as wakeup event. + + +Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC:: + + spi_controller { + tsc2046@0 { + reg = <0>; /* CS0 */ + compatible = "ti,tsc2046"; + interrupt-parent = <&gpio1>; + interrupts = <8 0>; /* BOOT6 / GPIO 8 */ + spi-max-frequency = <1000000>; + pendown-gpio = <&gpio1 8 0>; + vcc-supply = <®_vcc3>; + + ti,x-min = <0>; + ti,x-max = <8000>; + ti,y-min = <0>; + ti,y-max = <4800>; + ti,x-plate-ohms = <40>; + ti,pressure-max = <255>; + + linux,wakeup; + }; + }; diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 1c9c83a..31d1879 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -27,6 +27,9 @@ #include <linux/interrupt.h> #include <linux/slab.h> #include <linux/pm.h> +#include <linux/of.h> +#include <linux/of_gpio.h> +#include <linux/of_device.h> #include <linux/gpio.h> #include <linux/spi/spi.h> #include <linux/spi/ads7846.h> @@ -1202,6 +1205,99 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts) spi_message_add_tail(x, m); } +#ifdef CONFIG_OF +static const struct of_device_id ads7846_dt_ids[] = { + { .compatible = "ti,tsc2046", .data = (void *) 7846 }, + { .compatible = "ti,ads7843", .data = (void *) 7843 }, + { .compatible = "ti,ads7845", .data = (void *) 7845 }, + { .compatible = "ti,ads7846", .data = (void *) 7846 }, + { .compatible = "ti,ads7873", .data = (void *) 7873 }, + { } +}; +MODULE_DEVICE_TABLE(of, ads7846_dt_ids); + +static int ads7846_probe_dt(struct device *dev, struct ads7846 *ts) +{ + const struct of_device_id *match; + u32 val; + + match = of_match_device(ads7846_dt_ids, dev); + if (!match) + return -ENODEV; + + ts->model = (unsigned int) match->data; + + if (of_property_read_u32(dev->of_node, "ti,vref-delay-usecs", &val) == 0) + ts->vref_delay_usecs = val; + + if (of_property_read_u32(dev->of_node, "ti,vref-mv", &val) == 0) + ts->vref_mv = val; + + if (of_get_property(dev->of_node, "ti,keep-vref-on", NULL)) + ts->keep_vref_on = true; + + if (of_get_property(dev->of_node, "ti,swap-xy", NULL)) + ts->swap_xy = true; + + if (of_property_read_u32(dev->of_node, "ti,settle-delay-usec", + &val) == 0) + ts->settle_delay_usecs = val; + + if (of_property_read_u32(dev->of_node, "ti,penirq-recheck-delay-usecs", + &val) == 0) + ts->penirq_recheck_delay_usecs = val; + + if (of_property_read_u32(dev->of_node, "ti,x-plate-ohms", &val) == 0) + ts->x_plate_ohms = val; + + if (of_property_read_u32(dev->of_node, "ti,y-plate-ohms", &val) == 0) + ts->y_plate_ohms = val; + + if (of_property_read_u32(dev->of_node, "ti,x-min", &val) == 0) + ts->x_min = val; + + if (of_property_read_u32(dev->of_node, "ti,y-min", &val) == 0) + ts->y_min = val; + + if (of_property_read_u32(dev->of_node, "ti,x-max", &val) == 0) + ts->x_max = val; + + if (of_property_read_u32(dev->of_node, "ti,y-max", &val) == 0) + ts->y_max = val; + + if (of_property_read_u32(dev->of_node, "ti,pressure-min", &val) == 0) + ts->pressure_min = val; + + if (of_property_read_u32(dev->of_node, "ti,pressure-max", &val) == 0) + ts->pressure_max = val; + + if (of_property_read_u32(dev->of_node, "ti,debounce-max", &val) == 0) + ts->debounce_max = val; + + if (of_property_read_u32(dev->of_node, "ti,debounce-tol", &val) == 0) + ts->debounce_tol = val; + + if (of_property_read_u32(dev->of_node, "ti,debounce-rep", &val) == 0) + ts->debounce_rep = val; + + if (of_property_read_u32(dev->of_node, "ti,pendown-gpio-debounce", + &val) == 0) + ts->gpio_pendown_debounce = val; + + ts->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); + + if (of_get_property(dev->of_node, "linux,wakeup", NULL)) + ts->wakeup = true; + + return 0; +} +#else +static inline struct ads7846_platform_data ads7846_probe_dt(struct device *dev) +{ + return -ENODEV; +} +#endif + static int ads7846_probe(struct spi_device *spi) { struct ads7846 *ts; @@ -1216,11 +1312,6 @@ static int ads7846_probe(struct spi_device *spi) 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", @@ -1247,39 +1338,52 @@ static int ads7846_probe(struct spi_device *spi) } spi_set_drvdata(spi, ts); - ts->packet = packet; ts->spi = spi; ts->input = input_dev; - ts->vref_mv = pdata->vref_mv; - ts->swap_xy = pdata->swap_xy; - mutex_init(&ts->lock); init_waitqueue_head(&ts->wait); - ts->model = pdata->model; - ts->keep_vref_on = pdata->keep_vref_on; - ts->swap_xy = pdata->swap_xy; - ts->vref_delay_usecs = pdata->vref_delay_usecs; - ts->x_plate_ohms = pdata->x_plate_ohms; - ts->y_plate_ohms = pdata->y_plate_ohms; - ts->x_min = pdata->x_min; - ts->x_max = pdata->x_max; - ts->y_min = pdata->y_min; - ts->y_max = pdata->y_max; - ts->pressure_min = pdata->pressure_min; - ts->pressure_max = pdata->pressure_max; - ts->debounce_max = pdata->debounce_max; - ts->debounce_tol = pdata->debounce_tol; - ts->debounce_rep = pdata->debounce_rep; - ts->gpio_pendown = pdata->gpio_pendown; - ts->gpio_pendown_debounce = pdata->gpio_pendown_debounce; - ts->penirq_recheck_delay_usecs = pdata->penirq_recheck_delay_usecs; - ts->filter = pdata->filter; - ts->filter_cleanup = pdata->filter_cleanup; - ts->wait_for_sync = pdata->wait_for_sync; - ts->wakeup = pdata->wakeup; - ts->irq_flags = pdata->irq_flags; + if (pdata) { + ts->vref_mv = pdata->vref_mv; + ts->swap_xy = pdata->swap_xy; + ts->model = pdata->model; + ts->keep_vref_on = pdata->keep_vref_on; + ts->swap_xy = pdata->swap_xy; + ts->vref_delay_usecs = pdata->vref_delay_usecs; + ts->x_plate_ohms = pdata->x_plate_ohms; + ts->y_plate_ohms = pdata->y_plate_ohms; + ts->x_min = pdata->x_min; + ts->x_max = pdata->x_max; + ts->y_min = pdata->y_min; + ts->y_max = pdata->y_max; + ts->pressure_min = pdata->pressure_min; + ts->pressure_max = pdata->pressure_max; + ts->debounce_max = pdata->debounce_max; + ts->debounce_tol = pdata->debounce_tol; + ts->debounce_rep = pdata->debounce_rep; + ts->gpio_pendown = pdata->gpio_pendown; + ts->gpio_pendown_debounce = pdata->gpio_pendown_debounce; + ts->penirq_recheck_delay_usecs = pdata->penirq_recheck_delay_usecs; + ts->filter = pdata->filter; + ts->filter_cleanup = pdata->filter_cleanup; + ts->wait_for_sync = pdata->wait_for_sync; + ts->wakeup = pdata->wakeup; + ts->irq_flags = pdata->irq_flags; + + if (pdata->filter && pdata->filter_init) { + err = pdata->filter_init(pdata, &ts->filter_data); + if (err < 0) + goto err_free_mem; + } + } else { + err = ads7846_probe_dt(&spi->dev, ts); + if (err < 0) { + dev_dbg(&spi->dev, "no platform data and no DT match?\n"); + err = -ENODEV; + goto err_free_mem; + } + } if (ts->model == 0) ts->model = 7846; @@ -1296,19 +1400,15 @@ static int ads7846_probe(struct spi_device *spi) if (ts->wait_for_sync == NULL) ts->wait_for_sync = null_wait_for_sync; - if (pdata->filter != NULL) { - if (pdata->filter_init != NULL) { - err = pdata->filter_init(pdata, &ts->filter_data); - if (err < 0) - goto err_free_mem; + if (ts->filter == NULL) { + if (ts->debounce_max) { + if (ts->debounce_max < 2) + ts->debounce_max = 2; + ts->filter = ads7846_debounce_filter; + ts->filter_data = ts; + } else { + ts->filter = ads7846_no_filter; } - } else if (ts->debounce_max) { - if (ts->debounce_max < 2) - ts->debounce_max = 2; - ts->filter = ads7846_debounce_filter; - ts->filter_data = ts; - } else { - ts->filter = ads7846_no_filter; } err = ads7846_setup_pendown(spi, ts); @@ -1461,6 +1561,7 @@ static struct spi_driver ads7846_driver = { .name = "ads7846", .owner = THIS_MODULE, .pm = &ads7846_pm, + .of_match_table = of_match_ptr(ads7846_dt_ids), }, .probe = ads7846_probe, .remove = ads7846_remove, -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
