Input: ads7846 - add device tree bindings
Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Daniel Mack
Dmitry Torokhov
parent
57691a1e27
commit
a608026eac
2 changed files with 195 additions and 11 deletions
91
Documentation/devicetree/bindings/input/ads7846.txt
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91
Documentation/devicetree/bindings/input/ads7846.txt
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@ -0,0 +1,91 @@
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Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046
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SPI driven touch screen controllers.
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The node for this driver must be a child node of a SPI controller, hence
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all mandatory properties described in
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Documentation/devicetree/bindings/spi/spi-bus.txt
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must be specified.
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Additional required properties:
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compatible Must be one of the following, depending on the
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model:
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"ti,tsc2046"
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"ti,ads7843"
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"ti,ads7845"
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"ti,ads7846"
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"ti,ads7873"
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interrupt-parent
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interrupts An interrupt node describing the IRQ line the chip's
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!PENIRQ pin is connected to.
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vcc-supply A regulator node for the supply voltage.
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Optional properties:
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ti,vref-delay-usecs vref supply delay in usecs, 0 for
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external vref (u16).
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ti,vref-mv The VREF voltage, in millivolts (u16).
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ti,keep-vref-on set to keep vref on for differential
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measurements as well
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ti,swap-xy swap x and y axis
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ti,settle-delay-usec Settling time of the analog signals;
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a function of Vcc and the capacitance
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on the X/Y drivers. If set to non-zero,
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two samples are taken with settle_delay
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us apart, and the second one is used.
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~150 uSec with 0.01uF caps (u16).
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ti,penirq-recheck-delay-usecs If set to non-zero, after samples are
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taken this delay is applied and penirq
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is rechecked, to help avoid false
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events. This value is affected by the
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material used to build the touch layer
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(u16).
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ti,x-plate-ohms Resistance of the X-plate,
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in Ohms (u16).
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ti,y-plate-ohms Resistance of the Y-plate,
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in Ohms (u16).
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ti,x-min Minimum value on the X axis (u16).
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ti,y-min Minimum value on the Y axis (u16).
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ti,x-max Maximum value on the X axis (u16).
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ti,y-max Minimum value on the Y axis (u16).
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ti,pressure-min Minimum reported pressure value
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(threshold) - u16.
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ti,pressure-max Maximum reported pressure value (u16).
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ti,debounce-max Max number of additional readings per
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sample (u16).
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ti,debounce-tol Tolerance used for filtering (u16).
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ti,debounce-rep Additional consecutive good readings
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required after the first two (u16).
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ti,pendown-gpio-debounce Platform specific debounce time for the
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pendown-gpio (u32).
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pendown-gpio GPIO handle describing the pin the !PENIRQ
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line is connected to.
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linux,wakeup use any event on touchscreen as wakeup event.
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Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC::
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spi_controller {
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tsc2046@0 {
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reg = <0>; /* CS0 */
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compatible = "ti,tsc2046";
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interrupt-parent = <&gpio1>;
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interrupts = <8 0>; /* BOOT6 / GPIO 8 */
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spi-max-frequency = <1000000>;
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pendown-gpio = <&gpio1 8 0>;
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vcc-supply = <®_vcc3>;
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ti,x-min = /bits/ 16 <0>;
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ti,x-max = /bits/ 16 <8000>;
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ti,y-min = /bits/ 16 <0>;
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ti,y-max = /bits/ 16 <4800>;
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ti,x-plate-ohms = /bits/ 16 <40>;
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ti,pressure-max = /bits/ 16 <255>;
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linux,wakeup;
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};
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};
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@ -27,6 +27,9 @@
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/pm.h>
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#include <linux/of.h>
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#include <linux/of_gpio.h>
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#include <linux/of_device.h>
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#include <linux/gpio.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/ads7846.h>
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@ -1201,9 +1204,87 @@ static void ads7846_setup_spi_msg(struct ads7846 *ts,
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spi_message_add_tail(x, m);
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}
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#ifdef CONFIG_OF
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static const struct of_device_id ads7846_dt_ids[] = {
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{ .compatible = "ti,tsc2046", .data = (void *) 7846 },
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{ .compatible = "ti,ads7843", .data = (void *) 7843 },
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{ .compatible = "ti,ads7845", .data = (void *) 7845 },
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{ .compatible = "ti,ads7846", .data = (void *) 7846 },
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{ .compatible = "ti,ads7873", .data = (void *) 7873 },
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{ }
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};
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MODULE_DEVICE_TABLE(of, ads7846_dt_ids);
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static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
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{
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struct ads7846_platform_data *pdata;
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struct device_node *node = dev->of_node;
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const struct of_device_id *match;
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if (!node) {
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dev_err(dev, "Device does not have associated DT data\n");
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return ERR_PTR(-EINVAL);
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}
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match = of_match_device(ads7846_dt_ids, dev);
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if (!match) {
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dev_err(dev, "Unknown device model\n");
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return ERR_PTR(-EINVAL);
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}
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pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return ERR_PTR(-ENOMEM);
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pdata->model = (unsigned long)match->data;
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of_property_read_u16(node, "ti,vref-delay-usecs",
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&pdata->vref_delay_usecs);
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of_property_read_u16(node, "ti,vref-mv", &pdata->vref_mv);
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pdata->keep_vref_on = of_property_read_bool(node, "ti,keep-vref-on");
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pdata->swap_xy = of_property_read_bool(node, "ti,swap-xy");
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of_property_read_u16(node, "ti,settle-delay-usec",
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&pdata->settle_delay_usecs);
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of_property_read_u16(node, "ti,penirq-recheck-delay-usecs",
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&pdata->penirq_recheck_delay_usecs);
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of_property_read_u16(node, "ti,x-plate-ohms", &pdata->x_plate_ohms);
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of_property_read_u16(node, "ti,y-plate-ohms", &pdata->y_plate_ohms);
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of_property_read_u16(node, "ti,x-min", &pdata->x_min);
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of_property_read_u16(node, "ti,y-min", &pdata->y_min);
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of_property_read_u16(node, "ti,x-max", &pdata->x_max);
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of_property_read_u16(node, "ti,y-max", &pdata->y_max);
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of_property_read_u16(node, "ti,pressure-min", &pdata->pressure_min);
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of_property_read_u16(node, "ti,pressure-max", &pdata->pressure_max);
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of_property_read_u16(node, "ti,debounce-max", &pdata->debounce_max);
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of_property_read_u16(node, "ti,debounce-tol", &pdata->debounce_tol);
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of_property_read_u16(node, "ti,debounce-rep", &pdata->debounce_rep);
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of_property_read_u32(node, "ti,pendown-gpio-debounce",
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&pdata->gpio_pendown_debounce);
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pdata->wakeup = of_property_read_bool(node, "linux,wakeup");
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pdata->gpio_pendown = of_get_named_gpio(dev->of_node, "pendown-gpio", 0);
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return pdata;
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}
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#else
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static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
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{
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dev_err(dev, "no platform data defined\n");
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return ERR_PTR(-EINVAL);
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}
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#endif
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static int ads7846_probe(struct spi_device *spi)
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{
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const struct ads7846_platform_data *pdata = dev_get_platdata(&spi->dev);
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const struct ads7846_platform_data *pdata;
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struct ads7846 *ts;
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struct ads7846_packet *packet;
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struct input_dev *input_dev;
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@ -1212,22 +1293,18 @@ static int ads7846_probe(struct spi_device *spi)
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if (!spi->irq) {
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dev_dbg(&spi->dev, "no IRQ?\n");
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return -ENODEV;
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}
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if (!pdata) {
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dev_dbg(&spi->dev, "no platform data?\n");
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return -ENODEV;
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return -EINVAL;
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}
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/* don't exceed max specified sample rate */
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if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
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dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
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dev_err(&spi->dev, "f(sample) %d KHz?\n",
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(spi->max_speed_hz/SAMPLE_BITS)/1000);
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return -EINVAL;
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}
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/* We'd set TX word size 8 bits and RX word size to 13 bits ... except
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/*
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* We'd set TX word size 8 bits and RX word size to 13 bits ... except
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* that even if the hardware can do that, the SPI controller driver
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* may not. So we stick to very-portable 8 bit words, both RX and TX.
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*/
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@ -1250,17 +1327,25 @@ static int ads7846_probe(struct spi_device *spi)
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ts->packet = packet;
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ts->spi = spi;
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ts->input = input_dev;
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ts->vref_mv = pdata->vref_mv;
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ts->swap_xy = pdata->swap_xy;
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mutex_init(&ts->lock);
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init_waitqueue_head(&ts->wait);
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pdata = dev_get_platdata(&spi->dev);
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if (!pdata) {
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pdata = ads7846_probe_dt(&spi->dev);
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if (IS_ERR(pdata))
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return PTR_ERR(pdata);
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}
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ts->model = pdata->model ? : 7846;
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ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
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ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
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ts->pressure_max = pdata->pressure_max ? : ~0;
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ts->vref_mv = pdata->vref_mv;
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ts->swap_xy = pdata->swap_xy;
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if (pdata->filter != NULL) {
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if (pdata->filter_init != NULL) {
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err = pdata->filter_init(pdata, &ts->filter_data);
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@ -1370,6 +1455,13 @@ static int ads7846_probe(struct spi_device *spi)
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device_init_wakeup(&spi->dev, pdata->wakeup);
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/*
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* If device does not carry platform data we must have allocated it
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* when parsing DT data.
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*/
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if (!dev_get_platdata(&spi->dev))
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devm_kfree(&spi->dev, (void *)pdata);
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return 0;
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err_remove_attr_group:
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@ -1437,6 +1529,7 @@ static struct spi_driver ads7846_driver = {
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.name = "ads7846",
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.owner = THIS_MODULE,
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.pm = &ads7846_pm,
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.of_match_table = of_match_ptr(ads7846_dt_ids),
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},
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.probe = ads7846_probe,
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.remove = ads7846_remove,
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