1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Allwinner sun4i low res adc attached tablet keys driver
13  * There are 2 channels, currently this driver only supports channel 0 since
58 /* struct lradc_variant - Describe sun4i-a10-lradc-keys hardware variant
97 	u32 i, ints, val, voltage, diff, keycode = 0, closest = 0xffffffff;  in sun4i_lradc_irq()  local
99 	ints  = readl(lradc->base + LRADC_INTS);  in sun4i_lradc_irq()
107 		input_report_key(lradc->input, lradc->chan0_keycode, 0);  in sun4i_lradc_irq()
108 		lradc->chan0_keycode = 0;  in sun4i_lradc_irq()
111 	if ((ints & CHAN0_KEYDOWN_IRQ) && lradc->chan0_keycode == 0) {  in sun4i_lradc_irq()
112 		val = readl(lradc->base + LRADC_DATA0) & 0x3f;  in sun4i_lradc_irq()
113 		voltage = val * lradc->vref / 63;  in sun4i_lradc_irq()
115 		for (i = 0; i < lradc->chan0_map_count; i++) {  in sun4i_lradc_irq()
116 			diff = abs(lradc->chan0_map[i].voltage - voltage);  in sun4i_lradc_irq()
117 			if (diff < closest) {  in sun4i_lradc_irq()
118 				closest = diff;  in sun4i_lradc_irq()
119 				keycode = lradc->chan0_map[i].keycode;  in sun4i_lradc_irq()
123 		lradc->chan0_keycode = keycode;  in sun4i_lradc_irq()
124 		input_report_key(lradc->input, lradc->chan0_keycode, 1);  in sun4i_lradc_irq()
127 	input_sync(lradc->input);  in sun4i_lradc_irq()
129 	writel(ints, lradc->base + LRADC_INTS);  in sun4i_lradc_irq()
139 	error = regulator_enable(lradc->vref_supply);  in sun4i_lradc_open()
143 	lradc->vref = regulator_get_voltage(lradc->vref_supply) *  in sun4i_lradc_open()
144 		      lradc->variant->divisor_numerator /  in sun4i_lradc_open()
145 		      lradc->variant->divisor_denominator;  in sun4i_lradc_open()
151 		SAMPLE_RATE(0) | ENABLE(1), lradc->base + LRADC_CTRL);  in sun4i_lradc_open()
153 	writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC);  in sun4i_lradc_open()
164 		SAMPLE_RATE(2), lradc->base + LRADC_CTRL);  in sun4i_lradc_close()
165 	writel(0, lradc->base + LRADC_INTC);  in sun4i_lradc_close()
167 	regulator_disable(lradc->vref_supply);  in sun4i_lradc_close()
177 	np = dev->of_node;  in sun4i_lradc_load_dt_keymap()
179 		return -EINVAL;  in sun4i_lradc_load_dt_keymap()
181 	lradc->chan0_map_count = of_get_child_count(np);  in sun4i_lradc_load_dt_keymap()
182 	if (lradc->chan0_map_count == 0) {  in sun4i_lradc_load_dt_keymap()
184 		return -EINVAL;  in sun4i_lradc_load_dt_keymap()
187 	lradc->chan0_map = devm_kmalloc_array(dev, lradc->chan0_map_count,  in sun4i_lradc_load_dt_keymap()
190 	if (!lradc->chan0_map)  in sun4i_lradc_load_dt_keymap()
191 		return -ENOMEM;  in sun4i_lradc_load_dt_keymap()
195 		struct sun4i_lradc_keymap *map = &lradc->chan0_map[i];  in sun4i_lradc_load_dt_keymap()
202 			return -EINVAL;  in sun4i_lradc_load_dt_keymap()
205 		error = of_property_read_u32(pp, "voltage", &map->voltage);  in sun4i_lradc_load_dt_keymap()
209 			return -EINVAL;  in sun4i_lradc_load_dt_keymap()
212 		error = of_property_read_u32(pp, "linux,code", &map->keycode);  in sun4i_lradc_load_dt_keymap()
216 			return -EINVAL;  in sun4i_lradc_load_dt_keymap()
228 	struct device *dev = &pdev->dev;  in sun4i_lradc_probe()
234 		return -ENOMEM;  in sun4i_lradc_probe()
240 	lradc->variant = of_device_get_match_data(&pdev->dev);  in sun4i_lradc_probe()
241 	if (!lradc->variant) {  in sun4i_lradc_probe()
242 		dev_err(&pdev->dev, "Missing sun4i-a10-lradc-keys variant\n");  in sun4i_lradc_probe()
243 		return -EINVAL;  in sun4i_lradc_probe()
246 	lradc->vref_supply = devm_regulator_get(dev, "vref");  in sun4i_lradc_probe()
247 	if (IS_ERR(lradc->vref_supply))  in sun4i_lradc_probe()
248 		return PTR_ERR(lradc->vref_supply);  in sun4i_lradc_probe()
250 	lradc->dev = dev;  in sun4i_lradc_probe()
251 	lradc->input = devm_input_allocate_device(dev);  in sun4i_lradc_probe()
252 	if (!lradc->input)  in sun4i_lradc_probe()
253 		return -ENOMEM;  in sun4i_lradc_probe()
255 	lradc->input->name = pdev->name;  in sun4i_lradc_probe()
256 	lradc->input->phys = "sun4i_lradc/input0";  in sun4i_lradc_probe()
257 	lradc->input->open = sun4i_lradc_open;  in sun4i_lradc_probe()
258 	lradc->input->close = sun4i_lradc_close;  in sun4i_lradc_probe()
259 	lradc->input->id.bustype = BUS_HOST;  in sun4i_lradc_probe()
260 	lradc->input->id.vendor = 0x0001;  in sun4i_lradc_probe()
261 	lradc->input->id.product = 0x0001;  in sun4i_lradc_probe()
262 	lradc->input->id.version = 0x0100;  in sun4i_lradc_probe()
264 	__set_bit(EV_KEY, lradc->input->evbit);  in sun4i_lradc_probe()
265 	for (i = 0; i < lradc->chan0_map_count; i++)  in sun4i_lradc_probe()
266 		__set_bit(lradc->chan0_map[i].keycode, lradc->input->keybit);  in sun4i_lradc_probe()
268 	input_set_drvdata(lradc->input, lradc);  in sun4i_lradc_probe()
270 	lradc->base = devm_ioremap_resource(dev,  in sun4i_lradc_probe()
272 	if (IS_ERR(lradc->base))  in sun4i_lradc_probe()
273 		return PTR_ERR(lradc->base);  in sun4i_lradc_probe()
277 				 "sun4i-a10-lradc-keys", lradc);  in sun4i_lradc_probe()
281 	error = input_register_device(lradc->input);  in sun4i_lradc_probe()
289 	{ .compatible = "allwinner,sun4i-a10-lradc-keys",
291 	{ .compatible = "allwinner,sun8i-a83t-r-lradc",
299 		.name	= "sun4i-a10-lradc-keys",
307 MODULE_DESCRIPTION("Allwinner sun4i low res adc attached tablet keys driver");