1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Toradex Colibri VF50 Touchscreen driver
25 #define DRIVER_NAME			"colibri-vf50-ts"
27 #define VF_ADC_MAX			((1 << 12) - 1)
88 	gpiod_set_value(vf50_ts->gpio_ym, 1);  in vf50_ts_enable_touch_detection()
92 	 * Pull-Up on GPIO  in vf50_ts_enable_touch_detection()
94 	pinctrl_pm_select_idle_state(&vf50_ts->pdev->dev);  in vf50_ts_enable_touch_detection()
96 	/* Wait for the pull-up to be stable on high */  in vf50_ts_enable_touch_detection()
106 	struct device *dev = &vf50_ts->pdev->dev;  in vf50_ts_irq_bh()
111 	gpiod_set_value(vf50_ts->gpio_ym, 0);  in vf50_ts_irq_bh()
116 	while (!vf50_ts->stop_touchscreen) {  in vf50_ts_irq_bh()
117 		/* X-Direction */  in vf50_ts_irq_bh()
118 		val_x = adc_ts_measure(&vf50_ts->channels[0],  in vf50_ts_irq_bh()
119 				vf50_ts->gpio_xp, vf50_ts->gpio_xm);  in vf50_ts_irq_bh()
123 		/* Y-Direction */  in vf50_ts_irq_bh()
124 		val_y = adc_ts_measure(&vf50_ts->channels[1],  in vf50_ts_irq_bh()
125 				vf50_ts->gpio_yp, vf50_ts->gpio_ym);  in vf50_ts_irq_bh()
130 		 * Touch pressure  in vf50_ts_irq_bh()
133 		val_z1 = adc_ts_measure(&vf50_ts->channels[2],  in vf50_ts_irq_bh()
134 				vf50_ts->gpio_yp, vf50_ts->gpio_xm);  in vf50_ts_irq_bh()
137 		val_z2 = adc_ts_measure(&vf50_ts->channels[3],  in vf50_ts_irq_bh()
138 				vf50_ts->gpio_yp, vf50_ts->gpio_xm);  in vf50_ts_irq_bh()
146 			 * lower resistance means higher pressure  in vf50_ts_irq_bh()
150 			val_p = (r_x * val_z2) / val_z1 - r_x;  in vf50_ts_irq_bh()
156 		val_p = 2000 - val_p;  in vf50_ts_irq_bh()
162 		 * If touch pressure is too low, stop measuring and reenable  in vf50_ts_irq_bh()
165 		if (val_p < vf50_ts->min_pressure || val_p > 2000)  in vf50_ts_irq_bh()
169 		 * The pressure may not be enough for the first x and the  in vf50_ts_irq_bh()
170 		 * second y measurement, but, the pressure is ok when the  in vf50_ts_irq_bh()
181 			input_report_abs(vf50_ts->ts_input,  in vf50_ts_irq_bh()
182 					ABS_X, VF_ADC_MAX - val_x);  in vf50_ts_irq_bh()
183 			input_report_abs(vf50_ts->ts_input,  in vf50_ts_irq_bh()
184 					ABS_Y, VF_ADC_MAX - val_y);  in vf50_ts_irq_bh()
185 			input_report_abs(vf50_ts->ts_input,  in vf50_ts_irq_bh()
187 			input_report_key(vf50_ts->ts_input, BTN_TOUCH, 1);  in vf50_ts_irq_bh()
188 			input_sync(vf50_ts->ts_input);  in vf50_ts_irq_bh()
195 	/* Report no more touch, re-enable touch detection */  in vf50_ts_irq_bh()
196 	input_report_abs(vf50_ts->ts_input, ABS_PRESSURE, 0);  in vf50_ts_irq_bh()
197 	input_report_key(vf50_ts->ts_input, BTN_TOUCH, 0);  in vf50_ts_irq_bh()
198 	input_sync(vf50_ts->ts_input);  in vf50_ts_irq_bh()
208 	struct device *dev = &touchdev->pdev->dev;  in vf50_ts_open()
211 		dev_input->name);  in vf50_ts_open()
213 	touchdev->stop_touchscreen = false;  in vf50_ts_open()
215 	/* Mux detection before request IRQ, wait for pull-up to settle */  in vf50_ts_open()
224 	struct device *dev = &touchdev->pdev->dev;  in vf50_ts_close()
226 	touchdev->stop_touchscreen = true;  in vf50_ts_close()
230 	synchronize_irq(touchdev->pen_irq);  in vf50_ts_close()
232 	gpiod_set_value(touchdev->gpio_ym, 0);  in vf50_ts_close()
236 		dev_input->name);  in vf50_ts_close()
265 	struct device *dev = &pdev->dev;  in vf50_ts_probe()
287 		return -EINVAL;  in vf50_ts_probe()
292 		return -ENOMEM;  in vf50_ts_probe()
294 	touchdev->pdev = pdev;  in vf50_ts_probe()
295 	touchdev->channels = channels;  in vf50_ts_probe()
297 	error = of_property_read_u32(dev->of_node, "vf50-ts-min-pressure",  in vf50_ts_probe()
298 				 &touchdev->min_pressure);  in vf50_ts_probe()
305 		return -ENOMEM;  in vf50_ts_probe()
308 	input->name = DRIVER_NAME;  in vf50_ts_probe()
309 	input->id.bustype = BUS_HOST;  in vf50_ts_probe()
310 	input->dev.parent = dev;  in vf50_ts_probe()
311 	input->open = vf50_ts_open;  in vf50_ts_probe()
312 	input->close = vf50_ts_close;  in vf50_ts_probe()
319 	touchdev->ts_input = input;  in vf50_ts_probe()
328 	error = vf50_ts_get_gpiod(dev, &touchdev->gpio_xp, "xp", GPIOD_OUT_LOW);  in vf50_ts_probe()
332 	error = vf50_ts_get_gpiod(dev, &touchdev->gpio_xm,  in vf50_ts_probe()
337 	error = vf50_ts_get_gpiod(dev, &touchdev->gpio_yp, "yp", GPIOD_OUT_LOW);  in vf50_ts_probe()
341 	error = vf50_ts_get_gpiod(dev, &touchdev->gpio_ym, "ym", GPIOD_OUT_LOW);  in vf50_ts_probe()
345 	touchdev->pen_irq = platform_get_irq(pdev, 0);  in vf50_ts_probe()
346 	if (touchdev->pen_irq < 0)  in vf50_ts_probe()
347 		return touchdev->pen_irq;  in vf50_ts_probe()
349 	error = devm_request_threaded_irq(dev, touchdev->pen_irq,  in vf50_ts_probe()
354 			touchdev->pen_irq, error);  in vf50_ts_probe()
362 	{ .compatible = "toradex,vf50-touchscreen", },
377 MODULE_DESCRIPTION("Colibri VF50 Touchscreen driver");