1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Touchscreen driver for Marvell 88PM860x
4  *
5  * Copyright (C) 2009 Marvell International Ltd.
6  * 	Haojian Zhuang <haojian.zhuang@marvell.com>
7  */
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/platform_device.h>
12 #include <linux/i2c.h>
13 #include <linux/input.h>
14 #include <linux/mfd/88pm860x.h>
15 #include <linux/slab.h>
16 #include <linux/device.h>
17 
18 #define MEAS_LEN		(8)
19 #define ACCURATE_BIT		(12)
20 
21 /* touch register */
22 #define MEAS_EN3		(0x52)
23 
24 #define MEAS_TSIX_1		(0x8D)
25 #define MEAS_TSIX_2		(0x8E)
26 #define MEAS_TSIY_1		(0x8F)
27 #define MEAS_TSIY_2		(0x90)
28 #define MEAS_TSIZ1_1		(0x91)
29 #define MEAS_TSIZ1_2		(0x92)
30 #define MEAS_TSIZ2_1		(0x93)
31 #define MEAS_TSIZ2_2		(0x94)
32 
33 /* bit definitions of touch */
34 #define MEAS_PD_EN		(1 << 3)
35 #define MEAS_TSIX_EN		(1 << 4)
36 #define MEAS_TSIY_EN		(1 << 5)
37 #define MEAS_TSIZ1_EN		(1 << 6)
38 #define MEAS_TSIZ2_EN		(1 << 7)
39 
40 struct pm860x_touch {
41 	struct input_dev *idev;
42 	struct i2c_client *i2c;
43 	struct pm860x_chip *chip;
44 	int irq;
45 	int res_x;		/* resistor of Xplate */
46 };
47 
48 static irqreturn_t pm860x_touch_handler(int irq, void *data)
49 {
50 	struct pm860x_touch *touch = data;
51 	struct pm860x_chip *chip = touch->chip;
52 	unsigned char buf[MEAS_LEN];
53 	int x, y, pen_down;
54 	int z1, z2, rt = 0;
55 	int ret;
56 
57 	ret = pm860x_bulk_read(touch->i2c, MEAS_TSIX_1, MEAS_LEN, buf);
58 	if (ret < 0)
59 		goto out;
60 
61 	pen_down = buf[1] & (1 << 6);
62 	x = ((buf[0] & 0xFF) << 4) | (buf[1] & 0x0F);
63 	y = ((buf[2] & 0xFF) << 4) | (buf[3] & 0x0F);
64 	z1 = ((buf[4] & 0xFF) << 4) | (buf[5] & 0x0F);
65 	z2 = ((buf[6] & 0xFF) << 4) | (buf[7] & 0x0F);
66 
67 	if (pen_down) {
68 		if ((x != 0) && (z1 != 0) && (touch->res_x != 0)) {
69 			rt = z2 / z1 - 1;
70 			rt = (rt * touch->res_x * x) >> ACCURATE_BIT;
71 			dev_dbg(chip->dev, "z1:%d, z2:%d, rt:%d\n",
72 				z1, z2, rt);
73 		}
74 		input_report_abs(touch->idev, ABS_X, x);
75 		input_report_abs(touch->idev, ABS_Y, y);
76 		input_report_abs(touch->idev, ABS_PRESSURE, rt);
77 		input_report_key(touch->idev, BTN_TOUCH, 1);
78 		dev_dbg(chip->dev, "pen down at [%d, %d].\n", x, y);
79 	} else {
80 		input_report_abs(touch->idev, ABS_PRESSURE, 0);
81 		input_report_key(touch->idev, BTN_TOUCH, 0);
82 		dev_dbg(chip->dev, "pen release\n");
83 	}
84 	input_sync(touch->idev);
85 
86 out:
87 	return IRQ_HANDLED;
88 }
89 
90 static int pm860x_touch_open(struct input_dev *dev)
91 {
92 	struct pm860x_touch *touch = input_get_drvdata(dev);
93 	int data, ret;
94 
95 	data = MEAS_PD_EN | MEAS_TSIX_EN | MEAS_TSIY_EN
96 		| MEAS_TSIZ1_EN | MEAS_TSIZ2_EN;
97 	ret = pm860x_set_bits(touch->i2c, MEAS_EN3, data, data);
98 	if (ret < 0)
99 		goto out;
100 	return 0;
101 out:
102 	return ret;
103 }
104 
105 static void pm860x_touch_close(struct input_dev *dev)
106 {
107 	struct pm860x_touch *touch = input_get_drvdata(dev);
108 	int data;
109 
110 	data = MEAS_PD_EN | MEAS_TSIX_EN | MEAS_TSIY_EN
111 		| MEAS_TSIZ1_EN | MEAS_TSIZ2_EN;
112 	pm860x_set_bits(touch->i2c, MEAS_EN3, data, 0);
113 }
114 
115 #ifdef CONFIG_OF
116 static int pm860x_touch_dt_init(struct platform_device *pdev,
117 					  struct pm860x_chip *chip,
118 					  int *res_x)
119 {
120 	struct device_node *np = pdev->dev.parent->of_node;
121 	struct i2c_client *i2c = (chip->id == CHIP_PM8607) ? chip->client \
122 				 : chip->companion;
123 	int data, n, ret;
124 	if (!np)
125 		return -ENODEV;
126 	np = of_get_child_by_name(np, "touch");
127 	if (!np) {
128 		dev_err(&pdev->dev, "Can't find touch node\n");
129 		return -EINVAL;
130 	}
131 	/* set GPADC MISC1 register */
132 	data = 0;
133 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-prebias", &n))
134 		data |= (n << 1) & PM8607_GPADC_PREBIAS_MASK;
135 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-slot-cycle", &n))
136 		data |= (n << 3) & PM8607_GPADC_SLOT_CYCLE_MASK;
137 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-off-scale", &n))
138 		data |= (n << 5) & PM8607_GPADC_OFF_SCALE_MASK;
139 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-sw-cal", &n))
140 		data |= (n << 7) & PM8607_GPADC_SW_CAL_MASK;
141 	if (data) {
142 		ret = pm860x_reg_write(i2c, PM8607_GPADC_MISC1, data);
143 		if (ret < 0)
144 			goto err_put_node;
145 	}
146 	/* set tsi prebias time */
147 	if (!of_property_read_u32(np, "marvell,88pm860x-tsi-prebias", &data)) {
148 		ret = pm860x_reg_write(i2c, PM8607_TSI_PREBIAS, data);
149 		if (ret < 0)
150 			goto err_put_node;
151 	}
152 	/* set prebias & prechg time of pen detect */
153 	data = 0;
154 	if (!of_property_read_u32(np, "marvell,88pm860x-pen-prebias", &n))
155 		data |= n & PM8607_PD_PREBIAS_MASK;
156 	if (!of_property_read_u32(np, "marvell,88pm860x-pen-prechg", &n))
157 		data |= n & PM8607_PD_PRECHG_MASK;
158 	if (data) {
159 		ret = pm860x_reg_write(i2c, PM8607_PD_PREBIAS, data);
160 		if (ret < 0)
161 			goto err_put_node;
162 	}
163 	of_property_read_u32(np, "marvell,88pm860x-resistor-X", res_x);
164 
165 	of_node_put(np);
166 
167 	return 0;
168 
169 err_put_node:
170 	of_node_put(np);
171 
172 	return -EINVAL;
173 }
174 #else
175 #define pm860x_touch_dt_init(x, y, z)	(-1)
176 #endif
177 
178 static int pm860x_touch_probe(struct platform_device *pdev)
179 {
180 	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
181 	struct pm860x_touch_pdata *pdata = dev_get_platdata(&pdev->dev);
182 	struct pm860x_touch *touch;
183 	struct i2c_client *i2c = (chip->id == CHIP_PM8607) ? chip->client \
184 				 : chip->companion;
185 	int irq, ret, res_x = 0, data = 0;
186 
187 	irq = platform_get_irq(pdev, 0);
188 	if (irq < 0) {
189 		dev_err(&pdev->dev, "No IRQ resource!\n");
190 		return -EINVAL;
191 	}
192 
193 	if (pm860x_touch_dt_init(pdev, chip, &res_x)) {
194 		if (pdata) {
195 			/* set GPADC MISC1 register */
196 			data = 0;
197 			data |= (pdata->gpadc_prebias << 1)
198 				& PM8607_GPADC_PREBIAS_MASK;
199 			data |= (pdata->slot_cycle << 3)
200 				& PM8607_GPADC_SLOT_CYCLE_MASK;
201 			data |= (pdata->off_scale << 5)
202 				& PM8607_GPADC_OFF_SCALE_MASK;
203 			data |= (pdata->sw_cal << 7)
204 				& PM8607_GPADC_SW_CAL_MASK;
205 			if (data) {
206 				ret = pm860x_reg_write(i2c,
207 					PM8607_GPADC_MISC1, data);
208 				if (ret < 0)
209 					return -EINVAL;
210 			}
211 			/* set tsi prebias time */
212 			if (pdata->tsi_prebias) {
213 				data = pdata->tsi_prebias;
214 				ret = pm860x_reg_write(i2c,
215 					PM8607_TSI_PREBIAS, data);
216 				if (ret < 0)
217 					return -EINVAL;
218 			}
219 			/* set prebias & prechg time of pen detect */
220 			data = 0;
221 			data |= pdata->pen_prebias
222 				& PM8607_PD_PREBIAS_MASK;
223 			data |= (pdata->pen_prechg << 5)
224 				& PM8607_PD_PRECHG_MASK;
225 			if (data) {
226 				ret = pm860x_reg_write(i2c,
227 					PM8607_PD_PREBIAS, data);
228 				if (ret < 0)
229 					return -EINVAL;
230 			}
231 			res_x = pdata->res_x;
232 		} else {
233 			dev_err(&pdev->dev, "failed to get platform data\n");
234 			return -EINVAL;
235 		}
236 	}
237 	/* enable GPADC */
238 	ret = pm860x_set_bits(i2c, PM8607_GPADC_MISC1, PM8607_GPADC_EN,
239 			      PM8607_GPADC_EN);
240 	if (ret)
241 		return ret;
242 
243 	touch = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_touch),
244 			     GFP_KERNEL);
245 	if (!touch)
246 		return -ENOMEM;
247 
248 	touch->idev = devm_input_allocate_device(&pdev->dev);
249 	if (!touch->idev) {
250 		dev_err(&pdev->dev, "Failed to allocate input device!\n");
251 		return -ENOMEM;
252 	}
253 
254 	touch->idev->name = "88pm860x-touch";
255 	touch->idev->phys = "88pm860x/input0";
256 	touch->idev->id.bustype = BUS_I2C;
257 	touch->idev->dev.parent = &pdev->dev;
258 	touch->idev->open = pm860x_touch_open;
259 	touch->idev->close = pm860x_touch_close;
260 	touch->chip = chip;
261 	touch->i2c = i2c;
262 	touch->irq = irq;
263 	touch->res_x = res_x;
264 	input_set_drvdata(touch->idev, touch);
265 
266 	ret = devm_request_threaded_irq(&pdev->dev, touch->irq, NULL,
267 					pm860x_touch_handler, IRQF_ONESHOT,
268 					"touch", touch);
269 	if (ret < 0)
270 		return ret;
271 
272 	__set_bit(EV_ABS, touch->idev->evbit);
273 	__set_bit(ABS_X, touch->idev->absbit);
274 	__set_bit(ABS_Y, touch->idev->absbit);
275 	__set_bit(ABS_PRESSURE, touch->idev->absbit);
276 	__set_bit(EV_SYN, touch->idev->evbit);
277 	__set_bit(EV_KEY, touch->idev->evbit);
278 	__set_bit(BTN_TOUCH, touch->idev->keybit);
279 
280 	input_set_abs_params(touch->idev, ABS_X, 0, 1 << ACCURATE_BIT, 0, 0);
281 	input_set_abs_params(touch->idev, ABS_Y, 0, 1 << ACCURATE_BIT, 0, 0);
282 	input_set_abs_params(touch->idev, ABS_PRESSURE, 0, 1 << ACCURATE_BIT,
283 				0, 0);
284 
285 	ret = input_register_device(touch->idev);
286 	if (ret < 0) {
287 		dev_err(chip->dev, "Failed to register touch!\n");
288 		return ret;
289 	}
290 
291 	return 0;
292 }
293 
294 static struct platform_driver pm860x_touch_driver = {
295 	.driver	= {
296 		.name	= "88pm860x-touch",
297 	},
298 	.probe	= pm860x_touch_probe,
299 };
300 module_platform_driver(pm860x_touch_driver);
301 
302 MODULE_DESCRIPTION("Touchscreen driver for Marvell Semiconductor 88PM860x");
303 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
304 MODULE_LICENSE("GPL");
305 MODULE_ALIAS("platform:88pm860x-touch");
306 
307