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 
20 #define MEAS_LEN		(8)
21 #define ACCURATE_BIT		(12)
22 
23 /* touch register */
24 #define MEAS_EN3		(0x52)
25 
26 #define MEAS_TSIX_1		(0x8D)
27 #define MEAS_TSIX_2		(0x8E)
28 #define MEAS_TSIY_1		(0x8F)
29 #define MEAS_TSIY_2		(0x90)
30 #define MEAS_TSIZ1_1		(0x91)
31 #define MEAS_TSIZ1_2		(0x92)
32 #define MEAS_TSIZ2_1		(0x93)
33 #define MEAS_TSIZ2_2		(0x94)
34 
35 /* bit definitions of touch */
36 #define MEAS_PD_EN		(1 << 3)
37 #define MEAS_TSIX_EN		(1 << 4)
38 #define MEAS_TSIY_EN		(1 << 5)
39 #define MEAS_TSIZ1_EN		(1 << 6)
40 #define MEAS_TSIZ2_EN		(1 << 7)
41 
42 struct pm860x_touch {
43 	struct input_dev *idev;
44 	struct i2c_client *i2c;
45 	struct pm860x_chip *chip;
46 	int irq;
47 	int res_x;		/* resistor of Xplate */
48 };
49 
50 static irqreturn_t pm860x_touch_handler(int irq, void *data)
51 {
52 	struct pm860x_touch *touch = data;
53 	struct pm860x_chip *chip = touch->chip;
54 	unsigned char buf[MEAS_LEN];
55 	int x, y, pen_down;
56 	int z1, z2, rt = 0;
57 	int ret;
58 
59 	ret = pm860x_bulk_read(touch->i2c, MEAS_TSIX_1, MEAS_LEN, buf);
60 	if (ret < 0)
61 		goto out;
62 
63 	pen_down = buf[1] & (1 << 6);
64 	x = ((buf[0] & 0xFF) << 4) | (buf[1] & 0x0F);
65 	y = ((buf[2] & 0xFF) << 4) | (buf[3] & 0x0F);
66 	z1 = ((buf[4] & 0xFF) << 4) | (buf[5] & 0x0F);
67 	z2 = ((buf[6] & 0xFF) << 4) | (buf[7] & 0x0F);
68 
69 	if (pen_down) {
70 		if ((x != 0) && (z1 != 0) && (touch->res_x != 0)) {
71 			rt = z2 / z1 - 1;
72 			rt = (rt * touch->res_x * x) >> ACCURATE_BIT;
73 			dev_dbg(chip->dev, "z1:%d, z2:%d, rt:%d\n",
74 				z1, z2, rt);
75 		}
76 		input_report_abs(touch->idev, ABS_X, x);
77 		input_report_abs(touch->idev, ABS_Y, y);
78 		input_report_abs(touch->idev, ABS_PRESSURE, rt);
79 		input_report_key(touch->idev, BTN_TOUCH, 1);
80 		dev_dbg(chip->dev, "pen down at [%d, %d].\n", x, y);
81 	} else {
82 		input_report_abs(touch->idev, ABS_PRESSURE, 0);
83 		input_report_key(touch->idev, BTN_TOUCH, 0);
84 		dev_dbg(chip->dev, "pen release\n");
85 	}
86 	input_sync(touch->idev);
87 
88 out:
89 	return IRQ_HANDLED;
90 }
91 
92 static int pm860x_touch_open(struct input_dev *dev)
93 {
94 	struct pm860x_touch *touch = input_get_drvdata(dev);
95 	int data, ret;
96 
97 	data = MEAS_PD_EN | MEAS_TSIX_EN | MEAS_TSIY_EN
98 		| MEAS_TSIZ1_EN | MEAS_TSIZ2_EN;
99 	ret = pm860x_set_bits(touch->i2c, MEAS_EN3, data, data);
100 	if (ret < 0)
101 		goto out;
102 	return 0;
103 out:
104 	return ret;
105 }
106 
107 static void pm860x_touch_close(struct input_dev *dev)
108 {
109 	struct pm860x_touch *touch = input_get_drvdata(dev);
110 	int data;
111 
112 	data = MEAS_PD_EN | MEAS_TSIX_EN | MEAS_TSIY_EN
113 		| MEAS_TSIZ1_EN | MEAS_TSIZ2_EN;
114 	pm860x_set_bits(touch->i2c, MEAS_EN3, data, 0);
115 }
116 
117 #ifdef CONFIG_OF
118 static int pm860x_touch_dt_init(struct platform_device *pdev,
119 					  struct pm860x_chip *chip,
120 					  int *res_x)
121 {
122 	struct device_node *np = pdev->dev.parent->of_node;
123 	struct i2c_client *i2c = (chip->id == CHIP_PM8607) ? chip->client \
124 				 : chip->companion;
125 	int data, n, ret;
126 	if (!np)
127 		return -ENODEV;
128 	np = of_find_node_by_name(np, "touch");
129 	if (!np) {
130 		dev_err(&pdev->dev, "Can't find touch node\n");
131 		return -EINVAL;
132 	}
133 	/* set GPADC MISC1 register */
134 	data = 0;
135 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-prebias", &n))
136 		data |= (n << 1) & PM8607_GPADC_PREBIAS_MASK;
137 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-slot-cycle", &n))
138 		data |= (n << 3) & PM8607_GPADC_SLOT_CYCLE_MASK;
139 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-off-scale", &n))
140 		data |= (n << 5) & PM8607_GPADC_OFF_SCALE_MASK;
141 	if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-sw-cal", &n))
142 		data |= (n << 7) & PM8607_GPADC_SW_CAL_MASK;
143 	if (data) {
144 		ret = pm860x_reg_write(i2c, PM8607_GPADC_MISC1, data);
145 		if (ret < 0)
146 			return -EINVAL;
147 	}
148 	/* set tsi prebias time */
149 	if (!of_property_read_u32(np, "marvell,88pm860x-tsi-prebias", &data)) {
150 		ret = pm860x_reg_write(i2c, PM8607_TSI_PREBIAS, data);
151 		if (ret < 0)
152 			return -EINVAL;
153 	}
154 	/* set prebias & prechg time of pen detect */
155 	data = 0;
156 	if (!of_property_read_u32(np, "marvell,88pm860x-pen-prebias", &n))
157 		data |= n & PM8607_PD_PREBIAS_MASK;
158 	if (!of_property_read_u32(np, "marvell,88pm860x-pen-prechg", &n))
159 		data |= n & PM8607_PD_PRECHG_MASK;
160 	if (data) {
161 		ret = pm860x_reg_write(i2c, PM8607_PD_PREBIAS, data);
162 		if (ret < 0)
163 			return -EINVAL;
164 	}
165 	of_property_read_u32(np, "marvell,88pm860x-resistor-X", res_x);
166 	return 0;
167 }
168 #else
169 #define pm860x_touch_dt_init(x, y, z)	(-1)
170 #endif
171 
172 static int pm860x_touch_probe(struct platform_device *pdev)
173 {
174 	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
175 	struct pm860x_touch_pdata *pdata = pdev->dev.platform_data;
176 	struct pm860x_touch *touch;
177 	struct i2c_client *i2c = (chip->id == CHIP_PM8607) ? chip->client \
178 				 : chip->companion;
179 	int irq, ret, res_x = 0, data = 0;
180 
181 	irq = platform_get_irq(pdev, 0);
182 	if (irq < 0) {
183 		dev_err(&pdev->dev, "No IRQ resource!\n");
184 		return -EINVAL;
185 	}
186 
187 	if (pm860x_touch_dt_init(pdev, chip, &res_x)) {
188 		if (pdata) {
189 			/* set GPADC MISC1 register */
190 			data = 0;
191 			data |= (pdata->gpadc_prebias << 1)
192 				& PM8607_GPADC_PREBIAS_MASK;
193 			data |= (pdata->slot_cycle << 3)
194 				& PM8607_GPADC_SLOT_CYCLE_MASK;
195 			data |= (pdata->off_scale << 5)
196 				& PM8607_GPADC_OFF_SCALE_MASK;
197 			data |= (pdata->sw_cal << 7)
198 				& PM8607_GPADC_SW_CAL_MASK;
199 			if (data) {
200 				ret = pm860x_reg_write(i2c,
201 					PM8607_GPADC_MISC1, data);
202 				if (ret < 0)
203 					return -EINVAL;
204 			}
205 			/* set tsi prebias time */
206 			if (pdata->tsi_prebias) {
207 				data = pdata->tsi_prebias;
208 				ret = pm860x_reg_write(i2c,
209 					PM8607_TSI_PREBIAS, data);
210 				if (ret < 0)
211 					return -EINVAL;
212 			}
213 			/* set prebias & prechg time of pen detect */
214 			data = 0;
215 			data |= pdata->pen_prebias
216 				& PM8607_PD_PREBIAS_MASK;
217 			data |= (pdata->pen_prechg << 5)
218 				& PM8607_PD_PRECHG_MASK;
219 			if (data) {
220 				ret = pm860x_reg_write(i2c,
221 					PM8607_PD_PREBIAS, data);
222 				if (ret < 0)
223 					return -EINVAL;
224 			}
225 			res_x = pdata->res_x;
226 		} else {
227 			dev_err(&pdev->dev, "failed to get platform data\n");
228 			return -EINVAL;
229 		}
230 	}
231 	/* enable GPADC */
232 	ret = pm860x_set_bits(i2c, PM8607_GPADC_MISC1, PM8607_GPADC_EN,
233 			      PM8607_GPADC_EN);
234 	if (ret)
235 		return ret;
236 
237 	touch = kzalloc(sizeof(struct pm860x_touch), GFP_KERNEL);
238 	if (touch == NULL)
239 		return -ENOMEM;
240 	platform_set_drvdata(pdev, touch);
241 
242 	touch->idev = input_allocate_device();
243 	if (touch->idev == NULL) {
244 		dev_err(&pdev->dev, "Failed to allocate input device!\n");
245 		ret = -ENOMEM;
246 		goto out;
247 	}
248 
249 	touch->idev->name = "88pm860x-touch";
250 	touch->idev->phys = "88pm860x/input0";
251 	touch->idev->id.bustype = BUS_I2C;
252 	touch->idev->dev.parent = &pdev->dev;
253 	touch->idev->open = pm860x_touch_open;
254 	touch->idev->close = pm860x_touch_close;
255 	touch->chip = chip;
256 	touch->i2c = i2c;
257 	touch->irq = irq;
258 	touch->res_x = res_x;
259 	input_set_drvdata(touch->idev, touch);
260 
261 	ret = request_threaded_irq(touch->irq, NULL, pm860x_touch_handler,
262 				   IRQF_ONESHOT, "touch", touch);
263 	if (ret < 0)
264 		goto out_irq;
265 
266 	__set_bit(EV_ABS, touch->idev->evbit);
267 	__set_bit(ABS_X, touch->idev->absbit);
268 	__set_bit(ABS_Y, touch->idev->absbit);
269 	__set_bit(ABS_PRESSURE, touch->idev->absbit);
270 	__set_bit(EV_SYN, touch->idev->evbit);
271 	__set_bit(EV_KEY, touch->idev->evbit);
272 	__set_bit(BTN_TOUCH, touch->idev->keybit);
273 
274 	input_set_abs_params(touch->idev, ABS_X, 0, 1 << ACCURATE_BIT, 0, 0);
275 	input_set_abs_params(touch->idev, ABS_Y, 0, 1 << ACCURATE_BIT, 0, 0);
276 	input_set_abs_params(touch->idev, ABS_PRESSURE, 0, 1 << ACCURATE_BIT,
277 				0, 0);
278 
279 	ret = input_register_device(touch->idev);
280 	if (ret < 0) {
281 		dev_err(chip->dev, "Failed to register touch!\n");
282 		goto out_rg;
283 	}
284 
285 	platform_set_drvdata(pdev, touch);
286 	return 0;
287 out_rg:
288 	free_irq(touch->irq, touch);
289 out_irq:
290 	input_free_device(touch->idev);
291 out:
292 	kfree(touch);
293 	return ret;
294 }
295 
296 static int pm860x_touch_remove(struct platform_device *pdev)
297 {
298 	struct pm860x_touch *touch = platform_get_drvdata(pdev);
299 
300 	input_unregister_device(touch->idev);
301 	free_irq(touch->irq, touch);
302 	kfree(touch);
303 	return 0;
304 }
305 
306 static struct platform_driver pm860x_touch_driver = {
307 	.driver	= {
308 		.name	= "88pm860x-touch",
309 		.owner	= THIS_MODULE,
310 	},
311 	.probe	= pm860x_touch_probe,
312 	.remove	= pm860x_touch_remove,
313 };
314 module_platform_driver(pm860x_touch_driver);
315 
316 MODULE_DESCRIPTION("Touchscreen driver for Marvell Semiconductor 88PM860x");
317 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
318 MODULE_LICENSE("GPL");
319 MODULE_ALIAS("platform:88pm860x-touch");
320 
321