2 * Freescale i.MX6UL touchscreen controller driver
4 * Copyright (C) 2015 Freescale Semiconductor, Inc.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/input.h>
16 #include <linux/slab.h>
17 #include <linux/completion.h>
18 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 #include <linux/platform_device.h>
22 #include <linux/clk.h>
24 #include <linux/log2.h>
26 /* ADC configuration registers field define */
27 #define ADC_AIEN (0x1 << 7)
28 #define ADC_CONV_DISABLE 0x1F
29 #define ADC_AVGE (0x1 << 5)
30 #define ADC_CAL (0x1 << 7)
32 #define ADC_12BIT_MODE (0x2 << 2)
33 #define ADC_CONV_MODE_MASK (0x3 << 2)
34 #define ADC_IPG_CLK 0x00
35 #define ADC_INPUT_CLK_MASK 0x3
36 #define ADC_CLK_DIV_8 (0x03 << 5)
37 #define ADC_CLK_DIV_MASK (0x3 << 5)
38 #define ADC_SHORT_SAMPLE_MODE (0x0 << 4)
39 #define ADC_SAMPLE_MODE_MASK (0x1 << 4)
40 #define ADC_HARDWARE_TRIGGER (0x1 << 13)
41 #define ADC_AVGS_SHIFT 14
42 #define ADC_AVGS_MASK (0x3 << 14)
43 #define SELECT_CHANNEL_4 0x04
44 #define SELECT_CHANNEL_1 0x01
45 #define DISABLE_CONVERSION_INT (0x0 << 7)
48 #define REG_ADC_HC0 0x00
49 #define REG_ADC_HC1 0x04
50 #define REG_ADC_HC2 0x08
51 #define REG_ADC_HC3 0x0C
52 #define REG_ADC_HC4 0x10
53 #define REG_ADC_HS 0x14
54 #define REG_ADC_R0 0x18
55 #define REG_ADC_CFG 0x2C
56 #define REG_ADC_GC 0x30
57 #define REG_ADC_GS 0x34
59 #define ADC_TIMEOUT msecs_to_jiffies(100)
62 #define REG_TSC_BASIC_SETING 0x00
63 #define REG_TSC_PRE_CHARGE_TIME 0x10
64 #define REG_TSC_FLOW_CONTROL 0x20
65 #define REG_TSC_MEASURE_VALUE 0x30
66 #define REG_TSC_INT_EN 0x40
67 #define REG_TSC_INT_SIG_EN 0x50
68 #define REG_TSC_INT_STATUS 0x60
69 #define REG_TSC_DEBUG_MODE 0x70
70 #define REG_TSC_DEBUG_MODE2 0x80
72 /* TSC configuration registers field define */
73 #define DETECT_4_WIRE_MODE (0x0 << 4)
74 #define AUTO_MEASURE 0x1
75 #define MEASURE_SIGNAL 0x1
76 #define DETECT_SIGNAL (0x1 << 4)
77 #define VALID_SIGNAL (0x1 << 8)
78 #define MEASURE_INT_EN 0x1
79 #define MEASURE_SIG_EN 0x1
80 #define VALID_SIG_EN (0x1 << 8)
81 #define DE_GLITCH_2 (0x2 << 29)
82 #define START_SENSE (0x1 << 12)
83 #define TSC_DISABLE (0x1 << 16)
84 #define DETECT_MODE 0x2
88 struct input_dev *input;
89 void __iomem *tsc_regs;
90 void __iomem *adc_regs;
93 struct gpio_desc *xnur_gpio;
95 u32 measure_delay_time;
100 struct completion completion;
104 * TSC module need ADC to get the measure value. So
105 * before config TSC, we should initialize ADC module.
107 static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
113 unsigned long timeout;
115 reinit_completion(&tsc->completion);
117 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
118 adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK);
119 adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
120 adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK);
121 adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
122 if (tsc->average_enable) {
123 adc_cfg &= ~ADC_AVGS_MASK;
124 adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT;
126 adc_cfg &= ~ADC_HARDWARE_TRIGGER;
127 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
129 /* enable calibration interrupt */
131 adc_hc |= ADC_CONV_DISABLE;
132 writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);
134 /* start ADC calibration */
135 adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
137 if (tsc->average_enable)
139 writel(adc_gc, tsc->adc_regs + REG_ADC_GC);
141 timeout = wait_for_completion_timeout
142 (&tsc->completion, ADC_TIMEOUT);
144 dev_err(tsc->dev, "Timeout for adc calibration\n");
148 adc_gs = readl(tsc->adc_regs + REG_ADC_GS);
149 if (adc_gs & ADC_CALF) {
150 dev_err(tsc->dev, "ADC calibration failed\n");
154 /* TSC need the ADC work in hardware trigger */
155 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
156 adc_cfg |= ADC_HARDWARE_TRIGGER;
157 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
163 * This is a TSC workaround. Currently TSC misconnect two
164 * ADC channels, this function remap channel configure for
167 static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
169 u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
171 adc_hc0 = DISABLE_CONVERSION_INT;
172 writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
174 adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
175 writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);
177 adc_hc2 = DISABLE_CONVERSION_INT;
178 writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);
180 adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
181 writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);
183 adc_hc4 = DISABLE_CONVERSION_INT;
184 writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4);
188 * TSC setting, confige the pre-charge time and measure delay time.
189 * different touch screen may need different pre-charge time and
190 * measure delay time.
192 static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
194 u32 basic_setting = 0;
197 basic_setting |= tsc->measure_delay_time << 8;
198 basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
199 writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);
201 writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
203 writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
204 writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
205 writel(MEASURE_SIG_EN | VALID_SIG_EN,
206 tsc->tsc_regs + REG_TSC_INT_SIG_EN);
208 /* start sense detection */
209 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
210 start |= START_SENSE;
211 start &= ~TSC_DISABLE;
212 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
215 static int imx6ul_tsc_init(struct imx6ul_tsc *tsc)
219 err = imx6ul_adc_init(tsc);
222 imx6ul_tsc_channel_config(tsc);
228 static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
233 /* TSC controller enters to idle status */
234 tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
235 tsc_flow |= TSC_DISABLE;
236 writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
238 /* ADC controller enters to stop mode */
239 adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
240 adc_cfg |= ADC_CONV_DISABLE;
241 writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
244 /* Delay some time (max 2ms), wait the pre-charge done. */
245 static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
247 unsigned long timeout = jiffies + msecs_to_jiffies(2);
252 if (time_after(jiffies, timeout))
255 usleep_range(200, 400);
256 debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
257 state_machine = (debug_mode2 >> 20) & 0x7;
258 } while (state_machine != DETECT_MODE);
260 usleep_range(200, 400);
264 static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
266 struct imx6ul_tsc *tsc = dev_id;
272 status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
274 /* write 1 to clear the bit measure-signal */
275 writel(MEASURE_SIGNAL | DETECT_SIGNAL,
276 tsc->tsc_regs + REG_TSC_INT_STATUS);
278 /* It's a HW self-clean bit. Set this bit and start sense detection */
279 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
280 start |= START_SENSE;
281 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
283 if (status & MEASURE_SIGNAL) {
284 value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
285 x = (value >> 16) & 0x0fff;
289 * In detect mode, we can get the xnur gpio value,
290 * otherwise assume contact is stiull active.
292 if (!tsc_wait_detect_mode(tsc) ||
293 gpiod_get_value_cansleep(tsc->xnur_gpio)) {
294 input_report_key(tsc->input, BTN_TOUCH, 1);
295 input_report_abs(tsc->input, ABS_X, x);
296 input_report_abs(tsc->input, ABS_Y, y);
298 input_report_key(tsc->input, BTN_TOUCH, 0);
301 input_sync(tsc->input);
307 static irqreturn_t adc_irq_fn(int irq, void *dev_id)
309 struct imx6ul_tsc *tsc = dev_id;
313 coco = readl(tsc->adc_regs + REG_ADC_HS);
315 value = readl(tsc->adc_regs + REG_ADC_R0);
316 complete(&tsc->completion);
322 static int imx6ul_tsc_open(struct input_dev *input_dev)
324 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
327 err = clk_prepare_enable(tsc->adc_clk);
330 "Could not prepare or enable the adc clock: %d\n",
335 err = clk_prepare_enable(tsc->tsc_clk);
338 "Could not prepare or enable the tsc clock: %d\n",
340 clk_disable_unprepare(tsc->adc_clk);
344 return imx6ul_tsc_init(tsc);
347 static void imx6ul_tsc_close(struct input_dev *input_dev)
349 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
351 imx6ul_tsc_disable(tsc);
353 clk_disable_unprepare(tsc->tsc_clk);
354 clk_disable_unprepare(tsc->adc_clk);
357 static int imx6ul_tsc_probe(struct platform_device *pdev)
359 struct device_node *np = pdev->dev.of_node;
360 struct imx6ul_tsc *tsc;
361 struct input_dev *input_dev;
362 struct resource *tsc_mem;
363 struct resource *adc_mem;
369 tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL);
373 input_dev = devm_input_allocate_device(&pdev->dev);
377 input_dev->name = "iMX6UL Touchscreen Controller";
378 input_dev->id.bustype = BUS_HOST;
380 input_dev->open = imx6ul_tsc_open;
381 input_dev->close = imx6ul_tsc_close;
383 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
384 input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0);
385 input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0);
387 input_set_drvdata(input_dev, tsc);
389 tsc->dev = &pdev->dev;
390 tsc->input = input_dev;
391 init_completion(&tsc->completion);
393 tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN);
394 if (IS_ERR(tsc->xnur_gpio)) {
395 err = PTR_ERR(tsc->xnur_gpio);
397 "failed to request GPIO tsc_X- (xnur): %d\n", err);
401 tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
402 tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
403 if (IS_ERR(tsc->tsc_regs)) {
404 err = PTR_ERR(tsc->tsc_regs);
405 dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
409 adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
410 tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
411 if (IS_ERR(tsc->adc_regs)) {
412 err = PTR_ERR(tsc->adc_regs);
413 dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
417 tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
418 if (IS_ERR(tsc->tsc_clk)) {
419 err = PTR_ERR(tsc->tsc_clk);
420 dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
424 tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
425 if (IS_ERR(tsc->adc_clk)) {
426 err = PTR_ERR(tsc->adc_clk);
427 dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
431 tsc_irq = platform_get_irq(pdev, 0);
433 dev_err(&pdev->dev, "no tsc irq resource?\n");
437 adc_irq = platform_get_irq(pdev, 1);
439 dev_err(&pdev->dev, "no adc irq resource?\n");
443 err = devm_request_threaded_irq(tsc->dev, tsc_irq,
444 NULL, tsc_irq_fn, IRQF_ONESHOT,
445 dev_name(&pdev->dev), tsc);
448 "failed requesting tsc irq %d: %d\n",
453 err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0,
454 dev_name(&pdev->dev), tsc);
457 "failed requesting adc irq %d: %d\n",
462 err = of_property_read_u32(np, "measure-delay-time",
463 &tsc->measure_delay_time);
465 tsc->measure_delay_time = 0xffff;
467 err = of_property_read_u32(np, "pre-charge-time",
468 &tsc->pre_charge_time);
470 tsc->pre_charge_time = 0xfff;
472 err = of_property_read_u32(np, "touchscreen-average-samples",
477 switch (average_samples) {
479 tsc->average_enable = false;
480 tsc->average_select = 0; /* value unused; initialize anyway */
486 tsc->average_enable = true;
487 tsc->average_select = ilog2(average_samples) - 2;
491 "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n",
496 err = input_register_device(tsc->input);
499 "failed to register input device: %d\n", err);
503 platform_set_drvdata(pdev, tsc);
507 static int __maybe_unused imx6ul_tsc_suspend(struct device *dev)
509 struct platform_device *pdev = to_platform_device(dev);
510 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
511 struct input_dev *input_dev = tsc->input;
513 mutex_lock(&input_dev->mutex);
515 if (input_dev->users) {
516 imx6ul_tsc_disable(tsc);
518 clk_disable_unprepare(tsc->tsc_clk);
519 clk_disable_unprepare(tsc->adc_clk);
522 mutex_unlock(&input_dev->mutex);
527 static int __maybe_unused imx6ul_tsc_resume(struct device *dev)
529 struct platform_device *pdev = to_platform_device(dev);
530 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
531 struct input_dev *input_dev = tsc->input;
534 mutex_lock(&input_dev->mutex);
536 if (input_dev->users) {
537 retval = clk_prepare_enable(tsc->adc_clk);
541 retval = clk_prepare_enable(tsc->tsc_clk);
543 clk_disable_unprepare(tsc->adc_clk);
547 retval = imx6ul_tsc_init(tsc);
551 mutex_unlock(&input_dev->mutex);
555 static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
556 imx6ul_tsc_suspend, imx6ul_tsc_resume);
558 static const struct of_device_id imx6ul_tsc_match[] = {
559 { .compatible = "fsl,imx6ul-tsc", },
562 MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
564 static struct platform_driver imx6ul_tsc_driver = {
566 .name = "imx6ul-tsc",
567 .of_match_table = imx6ul_tsc_match,
568 .pm = &imx6ul_tsc_pm_ops,
570 .probe = imx6ul_tsc_probe,
572 module_platform_driver(imx6ul_tsc_driver);
574 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
575 MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver");
576 MODULE_LICENSE("GPL v2");