1 // SPDX-License-Identifier: GPL-2.0
3 // Freescale i.MX6UL touchscreen controller driver
5 // Copyright (C) 2015 Freescale Semiconductor, Inc.
7 #include <linux/errno.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/input.h>
12 #include <linux/slab.h>
13 #include <linux/completion.h>
14 #include <linux/delay.h>
16 #include <linux/interrupt.h>
17 #include <linux/platform_device.h>
18 #include <linux/clk.h>
20 #include <linux/log2.h>
22 /* ADC configuration registers field define */
23 #define ADC_AIEN (0x1 << 7)
24 #define ADC_CONV_DISABLE 0x1F
25 #define ADC_AVGE (0x1 << 5)
26 #define ADC_CAL (0x1 << 7)
28 #define ADC_12BIT_MODE (0x2 << 2)
29 #define ADC_CONV_MODE_MASK (0x3 << 2)
30 #define ADC_IPG_CLK 0x00
31 #define ADC_INPUT_CLK_MASK 0x3
32 #define ADC_CLK_DIV_8 (0x03 << 5)
33 #define ADC_CLK_DIV_MASK (0x3 << 5)
34 #define ADC_SHORT_SAMPLE_MODE (0x0 << 4)
35 #define ADC_SAMPLE_MODE_MASK (0x1 << 4)
36 #define ADC_HARDWARE_TRIGGER (0x1 << 13)
37 #define ADC_AVGS_SHIFT 14
38 #define ADC_AVGS_MASK (0x3 << 14)
39 #define SELECT_CHANNEL_4 0x04
40 #define SELECT_CHANNEL_1 0x01
41 #define DISABLE_CONVERSION_INT (0x0 << 7)
44 #define REG_ADC_HC0 0x00
45 #define REG_ADC_HC1 0x04
46 #define REG_ADC_HC2 0x08
47 #define REG_ADC_HC3 0x0C
48 #define REG_ADC_HC4 0x10
49 #define REG_ADC_HS 0x14
50 #define REG_ADC_R0 0x18
51 #define REG_ADC_CFG 0x2C
52 #define REG_ADC_GC 0x30
53 #define REG_ADC_GS 0x34
55 #define ADC_TIMEOUT msecs_to_jiffies(100)
58 #define REG_TSC_BASIC_SETING 0x00
59 #define REG_TSC_PRE_CHARGE_TIME 0x10
60 #define REG_TSC_FLOW_CONTROL 0x20
61 #define REG_TSC_MEASURE_VALUE 0x30
62 #define REG_TSC_INT_EN 0x40
63 #define REG_TSC_INT_SIG_EN 0x50
64 #define REG_TSC_INT_STATUS 0x60
65 #define REG_TSC_DEBUG_MODE 0x70
66 #define REG_TSC_DEBUG_MODE2 0x80
68 /* TSC configuration registers field define */
69 #define DETECT_4_WIRE_MODE (0x0 << 4)
70 #define AUTO_MEASURE 0x1
71 #define MEASURE_SIGNAL 0x1
72 #define DETECT_SIGNAL (0x1 << 4)
73 #define VALID_SIGNAL (0x1 << 8)
74 #define MEASURE_INT_EN 0x1
75 #define MEASURE_SIG_EN 0x1
76 #define VALID_SIG_EN (0x1 << 8)
77 #define DE_GLITCH_2 (0x2 << 29)
78 #define START_SENSE (0x1 << 12)
79 #define TSC_DISABLE (0x1 << 16)
80 #define DETECT_MODE 0x2
84 struct input_dev *input;
85 void __iomem *tsc_regs;
86 void __iomem *adc_regs;
89 struct gpio_desc *xnur_gpio;
91 u32 measure_delay_time;
96 struct completion completion;
100 * TSC module need ADC to get the measure value. So
101 * before config TSC, we should initialize ADC module.
103 static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
109 unsigned long timeout;
111 reinit_completion(&tsc->completion);
113 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
114 adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK);
115 adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
116 adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK);
117 adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
118 if (tsc->average_enable) {
119 adc_cfg &= ~ADC_AVGS_MASK;
120 adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT;
122 adc_cfg &= ~ADC_HARDWARE_TRIGGER;
123 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
125 /* enable calibration interrupt */
127 adc_hc |= ADC_CONV_DISABLE;
128 writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);
130 /* start ADC calibration */
131 adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
133 if (tsc->average_enable)
135 writel(adc_gc, tsc->adc_regs + REG_ADC_GC);
137 timeout = wait_for_completion_timeout
138 (&tsc->completion, ADC_TIMEOUT);
140 dev_err(tsc->dev, "Timeout for adc calibration\n");
144 adc_gs = readl(tsc->adc_regs + REG_ADC_GS);
145 if (adc_gs & ADC_CALF) {
146 dev_err(tsc->dev, "ADC calibration failed\n");
150 /* TSC need the ADC work in hardware trigger */
151 adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
152 adc_cfg |= ADC_HARDWARE_TRIGGER;
153 writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
159 * This is a TSC workaround. Currently TSC misconnect two
160 * ADC channels, this function remap channel configure for
163 static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
165 u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
167 adc_hc0 = DISABLE_CONVERSION_INT;
168 writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
170 adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
171 writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);
173 adc_hc2 = DISABLE_CONVERSION_INT;
174 writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);
176 adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
177 writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);
179 adc_hc4 = DISABLE_CONVERSION_INT;
180 writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4);
184 * TSC setting, confige the pre-charge time and measure delay time.
185 * different touch screen may need different pre-charge time and
186 * measure delay time.
188 static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
190 u32 basic_setting = 0;
193 basic_setting |= tsc->measure_delay_time << 8;
194 basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
195 writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);
197 writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
199 writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
200 writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
201 writel(MEASURE_SIG_EN | VALID_SIG_EN,
202 tsc->tsc_regs + REG_TSC_INT_SIG_EN);
204 /* start sense detection */
205 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
206 start |= START_SENSE;
207 start &= ~TSC_DISABLE;
208 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
211 static int imx6ul_tsc_init(struct imx6ul_tsc *tsc)
215 err = imx6ul_adc_init(tsc);
218 imx6ul_tsc_channel_config(tsc);
224 static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
229 /* TSC controller enters to idle status */
230 tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
231 tsc_flow |= TSC_DISABLE;
232 writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
234 /* ADC controller enters to stop mode */
235 adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
236 adc_cfg |= ADC_CONV_DISABLE;
237 writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
240 /* Delay some time (max 2ms), wait the pre-charge done. */
241 static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
243 unsigned long timeout = jiffies + msecs_to_jiffies(2);
248 if (time_after(jiffies, timeout))
251 usleep_range(200, 400);
252 debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
253 state_machine = (debug_mode2 >> 20) & 0x7;
254 } while (state_machine != DETECT_MODE);
256 usleep_range(200, 400);
260 static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
262 struct imx6ul_tsc *tsc = dev_id;
268 status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
270 /* write 1 to clear the bit measure-signal */
271 writel(MEASURE_SIGNAL | DETECT_SIGNAL,
272 tsc->tsc_regs + REG_TSC_INT_STATUS);
274 /* It's a HW self-clean bit. Set this bit and start sense detection */
275 start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
276 start |= START_SENSE;
277 writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
279 if (status & MEASURE_SIGNAL) {
280 value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
281 x = (value >> 16) & 0x0fff;
285 * In detect mode, we can get the xnur gpio value,
286 * otherwise assume contact is stiull active.
288 if (!tsc_wait_detect_mode(tsc) ||
289 gpiod_get_value_cansleep(tsc->xnur_gpio)) {
290 input_report_key(tsc->input, BTN_TOUCH, 1);
291 input_report_abs(tsc->input, ABS_X, x);
292 input_report_abs(tsc->input, ABS_Y, y);
294 input_report_key(tsc->input, BTN_TOUCH, 0);
297 input_sync(tsc->input);
303 static irqreturn_t adc_irq_fn(int irq, void *dev_id)
305 struct imx6ul_tsc *tsc = dev_id;
309 coco = readl(tsc->adc_regs + REG_ADC_HS);
311 value = readl(tsc->adc_regs + REG_ADC_R0);
312 complete(&tsc->completion);
318 static int imx6ul_tsc_start(struct imx6ul_tsc *tsc)
322 err = clk_prepare_enable(tsc->adc_clk);
325 "Could not prepare or enable the adc clock: %d\n",
330 err = clk_prepare_enable(tsc->tsc_clk);
333 "Could not prepare or enable the tsc clock: %d\n",
335 goto disable_adc_clk;
338 err = imx6ul_tsc_init(tsc);
340 goto disable_tsc_clk;
345 clk_disable_unprepare(tsc->tsc_clk);
347 clk_disable_unprepare(tsc->adc_clk);
351 static void imx6ul_tsc_stop(struct imx6ul_tsc *tsc)
353 imx6ul_tsc_disable(tsc);
355 clk_disable_unprepare(tsc->tsc_clk);
356 clk_disable_unprepare(tsc->adc_clk);
360 static int imx6ul_tsc_open(struct input_dev *input_dev)
362 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
364 return imx6ul_tsc_start(tsc);
367 static void imx6ul_tsc_close(struct input_dev *input_dev)
369 struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
371 imx6ul_tsc_stop(tsc);
374 static int imx6ul_tsc_probe(struct platform_device *pdev)
376 struct device_node *np = pdev->dev.of_node;
377 struct imx6ul_tsc *tsc;
378 struct input_dev *input_dev;
384 tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL);
388 input_dev = devm_input_allocate_device(&pdev->dev);
392 input_dev->name = "iMX6UL Touchscreen Controller";
393 input_dev->id.bustype = BUS_HOST;
395 input_dev->open = imx6ul_tsc_open;
396 input_dev->close = imx6ul_tsc_close;
398 input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
399 input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0);
400 input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0);
402 input_set_drvdata(input_dev, tsc);
404 tsc->dev = &pdev->dev;
405 tsc->input = input_dev;
406 init_completion(&tsc->completion);
408 tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN);
409 if (IS_ERR(tsc->xnur_gpio)) {
410 err = PTR_ERR(tsc->xnur_gpio);
412 "failed to request GPIO tsc_X- (xnur): %d\n", err);
416 tsc->tsc_regs = devm_platform_ioremap_resource(pdev, 0);
417 if (IS_ERR(tsc->tsc_regs)) {
418 err = PTR_ERR(tsc->tsc_regs);
419 dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
423 tsc->adc_regs = devm_platform_ioremap_resource(pdev, 1);
424 if (IS_ERR(tsc->adc_regs)) {
425 err = PTR_ERR(tsc->adc_regs);
426 dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
430 tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
431 if (IS_ERR(tsc->tsc_clk)) {
432 err = PTR_ERR(tsc->tsc_clk);
433 dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
437 tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
438 if (IS_ERR(tsc->adc_clk)) {
439 err = PTR_ERR(tsc->adc_clk);
440 dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
444 tsc_irq = platform_get_irq(pdev, 0);
448 adc_irq = platform_get_irq(pdev, 1);
452 err = devm_request_threaded_irq(tsc->dev, tsc_irq,
453 NULL, tsc_irq_fn, IRQF_ONESHOT,
454 dev_name(&pdev->dev), tsc);
457 "failed requesting tsc irq %d: %d\n",
462 err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0,
463 dev_name(&pdev->dev), tsc);
466 "failed requesting adc irq %d: %d\n",
471 err = of_property_read_u32(np, "measure-delay-time",
472 &tsc->measure_delay_time);
474 tsc->measure_delay_time = 0xffff;
476 err = of_property_read_u32(np, "pre-charge-time",
477 &tsc->pre_charge_time);
479 tsc->pre_charge_time = 0xfff;
481 err = of_property_read_u32(np, "touchscreen-average-samples",
486 switch (average_samples) {
488 tsc->average_enable = false;
489 tsc->average_select = 0; /* value unused; initialize anyway */
495 tsc->average_enable = true;
496 tsc->average_select = ilog2(average_samples) - 2;
500 "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n",
505 err = input_register_device(tsc->input);
508 "failed to register input device: %d\n", err);
512 platform_set_drvdata(pdev, tsc);
516 static int __maybe_unused imx6ul_tsc_suspend(struct device *dev)
518 struct platform_device *pdev = to_platform_device(dev);
519 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
520 struct input_dev *input_dev = tsc->input;
522 mutex_lock(&input_dev->mutex);
524 if (input_dev->users)
525 imx6ul_tsc_stop(tsc);
527 mutex_unlock(&input_dev->mutex);
532 static int __maybe_unused imx6ul_tsc_resume(struct device *dev)
534 struct platform_device *pdev = to_platform_device(dev);
535 struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
536 struct input_dev *input_dev = tsc->input;
539 mutex_lock(&input_dev->mutex);
541 if (input_dev->users)
542 retval = imx6ul_tsc_start(tsc);
544 mutex_unlock(&input_dev->mutex);
549 static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
550 imx6ul_tsc_suspend, imx6ul_tsc_resume);
552 static const struct of_device_id imx6ul_tsc_match[] = {
553 { .compatible = "fsl,imx6ul-tsc", },
556 MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
558 static struct platform_driver imx6ul_tsc_driver = {
560 .name = "imx6ul-tsc",
561 .of_match_table = imx6ul_tsc_match,
562 .pm = &imx6ul_tsc_pm_ops,
564 .probe = imx6ul_tsc_probe,
566 module_platform_driver(imx6ul_tsc_driver);
569 MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver");
570 MODULE_LICENSE("GPL v2");