1/*
  2 * TSI driver for Dialog DA9052
  3 *
  4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
  5 *
  6 * Author: David Dajun Chen <dchen@diasemi.com>
  7 *
  8 *  This program is free software; you can redistribute  it and/or modify it
  9 *  under  the terms of  the GNU General  Public License as published by the
 10 *  Free Software Foundation;  either version 2 of the  License, or (at your
 11 *  option) any later version.
 12 *
 13 */
 14#include <linux/module.h>
 15#include <linux/input.h>
 16#include <linux/delay.h>
 17#include <linux/platform_device.h>
 18#include <linux/interrupt.h>
 19
 20#include <linux/mfd/da9052/reg.h>
 21#include <linux/mfd/da9052/da9052.h>
 22
 23#define TSI_PEN_DOWN_STATUS 0x40
 24
 25struct da9052_tsi {
 26	struct da9052 *da9052;
 27	struct input_dev *dev;
 28	struct delayed_work ts_pen_work;
 29	struct mutex mutex;
 30	bool stopped;
 31	bool adc_on;
 32};
 33
 34static void da9052_ts_adc_toggle(struct da9052_tsi *tsi, bool on)
 35{
 36	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0, on);
 37	tsi->adc_on = on;
 38}
 39
 40static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
 41{
 42	struct da9052_tsi *tsi = data;
 43
 44	if (!tsi->stopped) {
 45		/* Mask PEN_DOWN event and unmask TSI_READY event */
 46		da9052_disable_irq_nosync(tsi->da9052, DA9052_IRQ_PENDOWN);
 47		da9052_enable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 48
 49		da9052_ts_adc_toggle(tsi, true);
 50
 51		schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
 52	}
 53
 54	return IRQ_HANDLED;
 55}
 56
 57static void da9052_ts_read(struct da9052_tsi *tsi)
 58{
 59	struct input_dev *input = tsi->dev;
 60	int ret;
 61	u16 x, y, z;
 62	u8 v;
 63
 64	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
 65	if (ret < 0)
 66		return;
 67
 68	x = (u16) ret;
 69
 70	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
 71	if (ret < 0)
 72		return;
 73
 74	y = (u16) ret;
 75
 76	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Z_MSB_REG);
 77	if (ret < 0)
 78		return;
 79
 80	z = (u16) ret;
 81
 82	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
 83	if (ret < 0)
 84		return;
 85
 86	v = (u8) ret;
 87
 88	x = ((x << 2) & 0x3fc) | (v & 0x3);
 89	y = ((y << 2) & 0x3fc) | ((v & 0xc) >> 2);
 90	z = ((z << 2) & 0x3fc) | ((v & 0x30) >> 4);
 91
 92	input_report_key(input, BTN_TOUCH, 1);
 93	input_report_abs(input, ABS_X, x);
 94	input_report_abs(input, ABS_Y, y);
 95	input_report_abs(input, ABS_PRESSURE, z);
 96	input_sync(input);
 97}
 98
 99static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
100{
101	struct da9052_tsi *tsi = data;
102
103	da9052_ts_read(tsi);
104
105	return IRQ_HANDLED;
106}
107
108static void da9052_ts_pen_work(struct work_struct *work)
109{
110	struct da9052_tsi *tsi = container_of(work, struct da9052_tsi,
111					      ts_pen_work.work);
112	if (!tsi->stopped) {
113		int ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
114		if (ret < 0 || (ret & TSI_PEN_DOWN_STATUS)) {
115			/* Pen is still DOWN (or read error) */
116			schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
117		} else {
118			struct input_dev *input = tsi->dev;
119
120			/* Pen UP */
121			da9052_ts_adc_toggle(tsi, false);
122
123			/* Report Pen UP */
124			input_report_key(input, BTN_TOUCH, 0);
125			input_report_abs(input, ABS_PRESSURE, 0);
126			input_sync(input);
127
128			/*
129			 * FIXME: Fixes the unhandled irq issue when quick
130			 * pen down and pen up events occurs
131			 */
132			ret = da9052_reg_update(tsi->da9052,
133						DA9052_EVENT_B_REG, 0xC0, 0xC0);
134			if (ret < 0)
135				return;
136
137			/* Mask TSI_READY event and unmask PEN_DOWN event */
138			da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
139			da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
140		}
141	}
142}
143
144static int da9052_ts_configure_gpio(struct da9052 *da9052)
145{
146	int error;
147
148	error = da9052_reg_update(da9052, DA9052_GPIO_2_3_REG, 0x30, 0);
149	if (error < 0)
150		return error;
151
152	error = da9052_reg_update(da9052, DA9052_GPIO_4_5_REG, 0x33, 0);
153	if (error < 0)
154		return error;
155
156	error = da9052_reg_update(da9052, DA9052_GPIO_6_7_REG, 0x33, 0);
157	if (error < 0)
158		return error;
159
160	return 0;
161}
162
163static int da9052_configure_tsi(struct da9052_tsi *tsi)
164{
165	int error;
166
167	error = da9052_ts_configure_gpio(tsi->da9052);
168	if (error)
169		return error;
170
171	/* Measure TSI sample every 1ms */
172	error = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
173				  1 << 6, 1 << 6);
174	if (error < 0)
175		return error;
176
177	/* TSI_DELAY: 3 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
178	error = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
179	if (error < 0)
180		return error;
181
182	/* Supply TSIRef through LD09 */
183	error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
184	if (error < 0)
185		return error;
186
187	return 0;
188}
189
190static int da9052_ts_input_open(struct input_dev *input_dev)
191{
192	struct da9052_tsi *tsi = input_get_drvdata(input_dev);
193
194	tsi->stopped = false;
195	mb();
196
197	/* Unmask PEN_DOWN event */
198	da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
199
200	/* Enable Pen Detect Circuit */
201	return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
202				 1 << 1, 1 << 1);
203}
204
205static void da9052_ts_input_close(struct input_dev *input_dev)
206{
207	struct da9052_tsi *tsi = input_get_drvdata(input_dev);
208
209	tsi->stopped = true;
210	mb();
211	da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
212	cancel_delayed_work_sync(&tsi->ts_pen_work);
213
214	if (tsi->adc_on) {
215		da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
216		da9052_ts_adc_toggle(tsi, false);
217
218		/*
219		 * If ADC was on that means that pendwn IRQ was disabled
220		 * twice and we need to enable it to keep enable/disable
221		 * counter balanced. IRQ is still off though.
222		 */
223		da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
224	}
225
226	/* Disable Pen Detect Circuit */
227	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
228}
229
230static int da9052_ts_probe(struct platform_device *pdev)
231{
232	struct da9052 *da9052;
233	struct da9052_tsi *tsi;
234	struct input_dev *input_dev;
235	int error;
236
237	da9052 = dev_get_drvdata(pdev->dev.parent);
238	if (!da9052)
239		return -EINVAL;
240
241	tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
242	input_dev = input_allocate_device();
243	if (!tsi || !input_dev) {
244		error = -ENOMEM;
245		goto err_free_mem;
246	}
247
248	tsi->da9052 = da9052;
249	tsi->dev = input_dev;
250	tsi->stopped = true;
251	INIT_DELAYED_WORK(&tsi->ts_pen_work, da9052_ts_pen_work);
252
253	input_dev->id.version = 0x0101;
254	input_dev->id.vendor = 0x15B6;
255	input_dev->id.product = 0x9052;
256	input_dev->name = "Dialog DA9052 TouchScreen Driver";
257	input_dev->dev.parent = &pdev->dev;
258	input_dev->open = da9052_ts_input_open;
259	input_dev->close = da9052_ts_input_close;
260
261	__set_bit(EV_ABS, input_dev->evbit);
262	__set_bit(EV_KEY, input_dev->evbit);
263	__set_bit(BTN_TOUCH, input_dev->keybit);
264
265	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
266	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
267	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
268
269	input_set_drvdata(input_dev, tsi);
270
271	/* Disable Pen Detect Circuit */
272	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
273
274	/* Disable ADC */
275	da9052_ts_adc_toggle(tsi, false);
276
277	error = da9052_request_irq(tsi->da9052, DA9052_IRQ_PENDOWN,
278				"pendown-irq", da9052_ts_pendwn_irq, tsi);
279	if (error) {
280		dev_err(tsi->da9052->dev,
281			"Failed to register PENDWN IRQ: %d\n", error);
282		goto err_free_mem;
283	}
284
285	error = da9052_request_irq(tsi->da9052, DA9052_IRQ_TSIREADY,
286				"tsiready-irq", da9052_ts_datardy_irq, tsi);
287	if (error) {
288		dev_err(tsi->da9052->dev,
289			"Failed to register TSIRDY IRQ :%d\n", error);
290		goto err_free_pendwn_irq;
291	}
292
293	/* Mask PEN_DOWN and TSI_READY events */
294	da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
295	da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
296
297	error = da9052_configure_tsi(tsi);
298	if (error)
299		goto err_free_datardy_irq;
300
301	error = input_register_device(tsi->dev);
302	if (error)
303		goto err_free_datardy_irq;
304
305	platform_set_drvdata(pdev, tsi);
306
307	return 0;
308
309err_free_datardy_irq:
310	da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
311err_free_pendwn_irq:
312	da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
313err_free_mem:
314	kfree(tsi);
315	input_free_device(input_dev);
316
317	return error;
318}
319
320static int  da9052_ts_remove(struct platform_device *pdev)
321{
322	struct da9052_tsi *tsi = platform_get_drvdata(pdev);
323
324	da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
325
326	da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
327	da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
328
329	input_unregister_device(tsi->dev);
330	kfree(tsi);
331
332	return 0;
333}
334
335static struct platform_driver da9052_tsi_driver = {
336	.probe	= da9052_ts_probe,
337	.remove	= da9052_ts_remove,
338	.driver	= {
339		.name	= "da9052-tsi",
340	},
341};
342
343module_platform_driver(da9052_tsi_driver);
344
345MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
346MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
347MODULE_LICENSE("GPL");
348MODULE_ALIAS("platform:da9052-tsi");