From a608026eacaee59cf0f1fa5caad60320f5b4a373 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Thu, 27 Jun 2013 23:42:17 -0700 Subject: Input: ads7846 - add device tree bindings Signed-off-by: Daniel Mack Signed-off-by: Dmitry Torokhov diff --git a/Documentation/devicetree/bindings/input/ads7846.txt b/Documentation/devicetree/bindings/input/ads7846.txt new file mode 100644 index 0000000..5f7619c --- /dev/null +++ b/Documentation/devicetree/bindings/input/ads7846.txt @@ -0,0 +1,91 @@ +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 (u16). + ti,vref-mv The VREF voltage, in millivolts (u16). + 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 (u16). + 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 + (u16). + ti,x-plate-ohms Resistance of the X-plate, + in Ohms (u16). + ti,y-plate-ohms Resistance of the Y-plate, + in Ohms (u16). + ti,x-min Minimum value on the X axis (u16). + ti,y-min Minimum value on the Y axis (u16). + ti,x-max Maximum value on the X axis (u16). + ti,y-max Minimum value on the Y axis (u16). + ti,pressure-min Minimum reported pressure value + (threshold) - u16. + ti,pressure-max Maximum reported pressure value (u16). + ti,debounce-max Max number of additional readings per + sample (u16). + ti,debounce-tol Tolerance used for filtering (u16). + ti,debounce-rep Additional consecutive good readings + required after the first two (u16). + ti,pendown-gpio-debounce Platform specific debounce time for the + pendown-gpio (u32). + 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 = /bits/ 16 <0>; + ti,x-max = /bits/ 16 <8000>; + ti,y-min = /bits/ 16 <0>; + ti,y-max = /bits/ 16 <4800>; + ti,x-plate-ohms = /bits/ 16 <40>; + ti,pressure-max = /bits/ 16 <255>; + + linux,wakeup; + }; + }; diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 5ff0419..ea19536 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -27,6 +27,9 @@ #include #include #include +#include +#include +#include #include #include #include @@ -1201,9 +1204,87 @@ 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 const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) +{ + struct ads7846_platform_data *pdata; + struct device_node *node = dev->of_node; + const struct of_device_id *match; + + if (!node) { + dev_err(dev, "Device does not have associated DT data\n"); + return ERR_PTR(-EINVAL); + } + + match = of_match_device(ads7846_dt_ids, dev); + if (!match) { + dev_err(dev, "Unknown device model\n"); + return ERR_PTR(-EINVAL); + } + + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return ERR_PTR(-ENOMEM); + + pdata->model = (unsigned long)match->data; + + of_property_read_u16(node, "ti,vref-delay-usecs", + &pdata->vref_delay_usecs); + of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv); + pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on"); + + pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy"); + + of_property_read_u16(node, "ti,settle-delay-usec", + &pdata->settle_delay_usecs); + of_property_read_u16(node, "ti,penirq-recheck-delay-usecs", + &pdata->penirq_recheck_delay_usecs); + + of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms); + of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms); + + of_property_read_u16(node, "ti,x-min", &pdata->x_min); + of_property_read_u16(node, "ti,y-min", &pdata->y_min); + of_property_read_u16(node, "ti,x-max", &pdata->x_max); + of_property_read_u16(node, "ti,y-max", &pdata->y_max); + + of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min); + of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max); + + of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max); + of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol); + of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep); + + of_property_read_u32(node, "ti,pendown-gpio-debounce", + &pdata->gpio_pendown_debounce); + + pdata->wakeup = of_property_read_bool(node, "linux,wakeup"); + + pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0); + + return pdata; +} +#else +static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev) +{ + dev_err(dev, "no platform data defined\n"); + return ERR_PTR(-EINVAL); +} +#endif + static int ads7846_probe(struct spi_device *spi) { - const struct ads7846_platform_data *pdata = dev_get_platdata(&spi->dev); + const struct ads7846_platform_data *pdata; struct ads7846 *ts; struct ads7846_packet *packet; struct input_dev *input_dev; @@ -1212,22 +1293,18 @@ static int ads7846_probe(struct spi_device *spi) if (!spi->irq) { dev_dbg(&spi->dev, "no IRQ?\n"); - return -ENODEV; - } - - if (!pdata) { - dev_dbg(&spi->dev, "no platform data?\n"); - return -ENODEV; + return -EINVAL; } /* don't exceed max specified sample rate */ if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) { - dev_dbg(&spi->dev, "f(sample) %d KHz?\n", + dev_err(&spi->dev, "f(sample) %d KHz?\n", (spi->max_speed_hz/SAMPLE_BITS)/1000); return -EINVAL; } - /* We'd set TX word size 8 bits and RX word size to 13 bits ... except + /* + * We'd set TX word size 8 bits and RX word size to 13 bits ... except * that even if the hardware can do that, the SPI controller driver * may not. So we stick to very-portable 8 bit words, both RX and TX. */ @@ -1250,17 +1327,25 @@ static int ads7846_probe(struct spi_device *spi) 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); + pdata = dev_get_platdata(&spi->dev); + if (!pdata) { + pdata = ads7846_probe_dt(&spi->dev); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + } + ts->model = pdata->model ? : 7846; ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; ts->pressure_max = pdata->pressure_max ? : ~0; + ts->vref_mv = pdata->vref_mv; + ts->swap_xy = pdata->swap_xy; + if (pdata->filter != NULL) { if (pdata->filter_init != NULL) { err = pdata->filter_init(pdata, &ts->filter_data); @@ -1370,6 +1455,13 @@ static int ads7846_probe(struct spi_device *spi) device_init_wakeup(&spi->dev, pdata->wakeup); + /* + * If device does not carry platform data we must have allocated it + * when parsing DT data. + */ + if (!dev_get_platdata(&spi->dev)) + devm_kfree(&spi->dev, (void *)pdata); + return 0; err_remove_attr_group: @@ -1437,6 +1529,7 @@ 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, -- cgit v0.10.2