1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * TSI driver for Dialog DA9052
  4 *
  5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
  6 *
  7 * Author: David Dajun Chen <dchen@diasemi.com>
  8 */
  9#include <linux/module.h>
 10#include <linux/input.h>
 11#include <linux/delay.h>
 12#include <linux/platform_device.h>
 13#include <linux/interrupt.h>
 14
 15#include <linux/mfd/da9052/reg.h>
 16#include <linux/mfd/da9052/da9052.h>
 17
 18#define TSI_PEN_DOWN_STATUS 0x40
 19
 20struct da9052_tsi {
 21	struct da9052 *da9052;
 22	struct input_dev *dev;
 23	struct delayed_work ts_pen_work;
 24	bool stopped;
 25	bool adc_on;
 26};
 27
 28static void da9052_ts_adc_toggle(struct da9052_tsi *tsi, bool on)
 29{
 30	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0, on);
 31	tsi->adc_on = on;
 32}
 33
 34static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
 35{
 36	struct da9052_tsi *tsi = data;
 37
 38	if (!tsi->stopped) {
 39		/* Mask PEN_DOWN event and unmask TSI_READY event */
 40		da9052_disable_irq_nosync(tsi->da9052, DA9052_IRQ_PENDOWN);
 41		da9052_enable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 42
 43		da9052_ts_adc_toggle(tsi, true);
 44
 45		schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
 46	}
 47
 48	return IRQ_HANDLED;
 49}
 50
 51static void da9052_ts_read(struct da9052_tsi *tsi)
 52{
 53	struct input_dev *input = tsi->dev;
 54	int ret;
 55	u16 x, y, z;
 56	u8 v;
 57
 58	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
 59	if (ret < 0)
 60		return;
 61
 62	x = (u16) ret;
 63
 64	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
 65	if (ret < 0)
 66		return;
 67
 68	y = (u16) ret;
 69
 70	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Z_MSB_REG);
 71	if (ret < 0)
 72		return;
 73
 74	z = (u16) ret;
 75
 76	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
 77	if (ret < 0)
 78		return;
 79
 80	v = (u8) ret;
 81
 82	x = ((x << 2) & 0x3fc) | (v & 0x3);
 83	y = ((y << 2) & 0x3fc) | ((v & 0xc) >> 2);
 84	z = ((z << 2) & 0x3fc) | ((v & 0x30) >> 4);
 85
 86	input_report_key(input, BTN_TOUCH, 1);
 87	input_report_abs(input, ABS_X, x);
 88	input_report_abs(input, ABS_Y, y);
 89	input_report_abs(input, ABS_PRESSURE, z);
 90	input_sync(input);
 91}
 92
 93static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
 94{
 95	struct da9052_tsi *tsi = data;
 96
 97	da9052_ts_read(tsi);
 98
 99	return IRQ_HANDLED;
100}
101
102static void da9052_ts_pen_work(struct work_struct *work)
103{
104	struct da9052_tsi *tsi = container_of(work, struct da9052_tsi,
105					      ts_pen_work.work);
106	if (!tsi->stopped) {
107		int ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
108		if (ret < 0 || (ret & TSI_PEN_DOWN_STATUS)) {
109			/* Pen is still DOWN (or read error) */
110			schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
111		} else {
112			struct input_dev *input = tsi->dev;
113
114			/* Pen UP */
115			da9052_ts_adc_toggle(tsi, false);
116
117			/* Report Pen UP */
118			input_report_key(input, BTN_TOUCH, 0);
119			input_report_abs(input, ABS_PRESSURE, 0);
120			input_sync(input);
121
122			/*
123			 * FIXME: Fixes the unhandled irq issue when quick
124			 * pen down and pen up events occurs
125			 */
126			ret = da9052_reg_update(tsi->da9052,
127						DA9052_EVENT_B_REG, 0xC0, 0xC0);
128			if (ret < 0)
129				return;
130
131			/* Mask TSI_READY event and unmask PEN_DOWN event */
132			da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
133			da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
134		}
135	}
136}
137
138static int da9052_ts_configure_gpio(struct da9052 *da9052)
139{
140	int error;
141
142	error = da9052_reg_update(da9052, DA9052_GPIO_2_3_REG, 0x30, 0);
143	if (error < 0)
144		return error;
145
146	error = da9052_reg_update(da9052, DA9052_GPIO_4_5_REG, 0x33, 0);
147	if (error < 0)
148		return error;
149
150	error = da9052_reg_update(da9052, DA9052_GPIO_6_7_REG, 0x33, 0);
151	if (error < 0)
152		return error;
153
154	return 0;
155}
156
157static int da9052_configure_tsi(struct da9052_tsi *tsi)
158{
159	int error;
160
161	error = da9052_ts_configure_gpio(tsi->da9052);
162	if (error)
163		return error;
164
165	/* Measure TSI sample every 1ms */
166	error = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
167				  1 << 6, 1 << 6);
168	if (error < 0)
169		return error;
170
171	/* TSI_DELAY: 3 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
172	error = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
173	if (error < 0)
174		return error;
175
176	/* Supply TSIRef through LD09 */
177	error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
178	if (error < 0)
179		return error;
180
181	return 0;
182}
183
184static int da9052_ts_input_open(struct input_dev *input_dev)
185{
186	struct da9052_tsi *tsi = input_get_drvdata(input_dev);
187
188	tsi->stopped = false;
189	mb();
190
191	/* Unmask PEN_DOWN event */
192	da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
193
194	/* Enable Pen Detect Circuit */
195	return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
196				 1 << 1, 1 << 1);
197}
198
199static void da9052_ts_input_close(struct input_dev *input_dev)
200{
201	struct da9052_tsi *tsi = input_get_drvdata(input_dev);
202
203	tsi->stopped = true;
204	mb();
205	da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
206	cancel_delayed_work_sync(&tsi->ts_pen_work);
207
208	if (tsi->adc_on) {
209		da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
210		da9052_ts_adc_toggle(tsi, false);
211
212		/*
213		 * If ADC was on that means that pendwn IRQ was disabled
214		 * twice and we need to enable it to keep enable/disable
215		 * counter balanced. IRQ is still off though.
216		 */
217		da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
218	}
219
220	/* Disable Pen Detect Circuit */
221	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
222}
223
224static int da9052_ts_probe(struct platform_device *pdev)
225{
226	struct da9052 *da9052;
227	struct da9052_tsi *tsi;
228	struct input_dev *input_dev;
229	int error;
230
231	da9052 = dev_get_drvdata(pdev->dev.parent);
232	if (!da9052)
233		return -EINVAL;
234
235	tsi = kzalloc(sizeof(*tsi), GFP_KERNEL);
236	input_dev = input_allocate_device();
237	if (!tsi || !input_dev) {
238		error = -ENOMEM;
239		goto err_free_mem;
240	}
241
242	tsi->da9052 = da9052;
243	tsi->dev = input_dev;
244	tsi->stopped = true;
245	INIT_DELAYED_WORK(&tsi->ts_pen_work, da9052_ts_pen_work);
246
247	input_dev->id.version = 0x0101;
248	input_dev->id.vendor = 0x15B6;
249	input_dev->id.product = 0x9052;
250	input_dev->name = "Dialog DA9052 TouchScreen Driver";
251	input_dev->dev.parent = &pdev->dev;
252	input_dev->open = da9052_ts_input_open;
253	input_dev->close = da9052_ts_input_close;
254
255	__set_bit(EV_ABS, input_dev->evbit);
256	__set_bit(EV_KEY, input_dev->evbit);
257	__set_bit(BTN_TOUCH, input_dev->keybit);
258
259	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
260	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
261	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
262
263	input_set_drvdata(input_dev, tsi);
264
265	/* Disable Pen Detect Circuit */
266	da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
267
268	/* Disable ADC */
269	da9052_ts_adc_toggle(tsi, false);
270
271	error = da9052_request_irq(tsi->da9052, DA9052_IRQ_PENDOWN,
272				"pendown-irq", da9052_ts_pendwn_irq, tsi);
273	if (error) {
274		dev_err(tsi->da9052->dev,
275			"Failed to register PENDWN IRQ: %d\n", error);
276		goto err_free_mem;
277	}
278
279	error = da9052_request_irq(tsi->da9052, DA9052_IRQ_TSIREADY,
280				"tsiready-irq", da9052_ts_datardy_irq, tsi);
281	if (error) {
282		dev_err(tsi->da9052->dev,
283			"Failed to register TSIRDY IRQ :%d\n", error);
284		goto err_free_pendwn_irq;
285	}
286
287	/* Mask PEN_DOWN and TSI_READY events */
288	da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
289	da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
290
291	error = da9052_configure_tsi(tsi);
292	if (error)
293		goto err_free_datardy_irq;
294
295	error = input_register_device(tsi->dev);
296	if (error)
297		goto err_free_datardy_irq;
298
299	platform_set_drvdata(pdev, tsi);
300
301	return 0;
302
303err_free_datardy_irq:
304	da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
305err_free_pendwn_irq:
306	da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
307err_free_mem:
308	kfree(tsi);
309	input_free_device(input_dev);
310
311	return error;
312}
313
314static void da9052_ts_remove(struct platform_device *pdev)
315{
316	struct da9052_tsi *tsi = platform_get_drvdata(pdev);
317
318	da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
319
320	da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
321	da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
322
323	input_unregister_device(tsi->dev);
324	kfree(tsi);
325}
326
327static struct platform_driver da9052_tsi_driver = {
328	.probe	= da9052_ts_probe,
329	.remove	= da9052_ts_remove,
330	.driver	= {
331		.name	= "da9052-tsi",
332	},
333};
334
335module_platform_driver(da9052_tsi_driver);
336
337MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
338MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
339MODULE_LICENSE("GPL");
340MODULE_ALIAS("platform:da9052-tsi");