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