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_open(struct input_dev
*input_dev
)
320 struct imx6ul_tsc
*tsc
= input_get_drvdata(input_dev
);
323 err
= clk_prepare_enable(tsc
->adc_clk
);
326 "Could not prepare or enable the adc clock: %d\n",
331 err
= clk_prepare_enable(tsc
->tsc_clk
);
334 "Could not prepare or enable the tsc clock: %d\n",
336 goto disable_adc_clk
;
339 err
= imx6ul_tsc_init(tsc
);
341 goto disable_tsc_clk
;
346 clk_disable_unprepare(tsc
->tsc_clk
);
348 clk_disable_unprepare(tsc
->adc_clk
);
352 static void imx6ul_tsc_close(struct input_dev
*input_dev
)
354 struct imx6ul_tsc
*tsc
= input_get_drvdata(input_dev
);
356 imx6ul_tsc_disable(tsc
);
358 clk_disable_unprepare(tsc
->tsc_clk
);
359 clk_disable_unprepare(tsc
->adc_clk
);
362 static int imx6ul_tsc_probe(struct platform_device
*pdev
)
364 struct device_node
*np
= pdev
->dev
.of_node
;
365 struct imx6ul_tsc
*tsc
;
366 struct input_dev
*input_dev
;
367 struct resource
*tsc_mem
;
368 struct resource
*adc_mem
;
374 tsc
= devm_kzalloc(&pdev
->dev
, sizeof(*tsc
), GFP_KERNEL
);
378 input_dev
= devm_input_allocate_device(&pdev
->dev
);
382 input_dev
->name
= "iMX6UL Touchscreen Controller";
383 input_dev
->id
.bustype
= BUS_HOST
;
385 input_dev
->open
= imx6ul_tsc_open
;
386 input_dev
->close
= imx6ul_tsc_close
;
388 input_set_capability(input_dev
, EV_KEY
, BTN_TOUCH
);
389 input_set_abs_params(input_dev
, ABS_X
, 0, 0xFFF, 0, 0);
390 input_set_abs_params(input_dev
, ABS_Y
, 0, 0xFFF, 0, 0);
392 input_set_drvdata(input_dev
, tsc
);
394 tsc
->dev
= &pdev
->dev
;
395 tsc
->input
= input_dev
;
396 init_completion(&tsc
->completion
);
398 tsc
->xnur_gpio
= devm_gpiod_get(&pdev
->dev
, "xnur", GPIOD_IN
);
399 if (IS_ERR(tsc
->xnur_gpio
)) {
400 err
= PTR_ERR(tsc
->xnur_gpio
);
402 "failed to request GPIO tsc_X- (xnur): %d\n", err
);
406 tsc_mem
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
407 tsc
->tsc_regs
= devm_ioremap_resource(&pdev
->dev
, tsc_mem
);
408 if (IS_ERR(tsc
->tsc_regs
)) {
409 err
= PTR_ERR(tsc
->tsc_regs
);
410 dev_err(&pdev
->dev
, "failed to remap tsc memory: %d\n", err
);
414 adc_mem
= platform_get_resource(pdev
, IORESOURCE_MEM
, 1);
415 tsc
->adc_regs
= devm_ioremap_resource(&pdev
->dev
, adc_mem
);
416 if (IS_ERR(tsc
->adc_regs
)) {
417 err
= PTR_ERR(tsc
->adc_regs
);
418 dev_err(&pdev
->dev
, "failed to remap adc memory: %d\n", err
);
422 tsc
->tsc_clk
= devm_clk_get(&pdev
->dev
, "tsc");
423 if (IS_ERR(tsc
->tsc_clk
)) {
424 err
= PTR_ERR(tsc
->tsc_clk
);
425 dev_err(&pdev
->dev
, "failed getting tsc clock: %d\n", err
);
429 tsc
->adc_clk
= devm_clk_get(&pdev
->dev
, "adc");
430 if (IS_ERR(tsc
->adc_clk
)) {
431 err
= PTR_ERR(tsc
->adc_clk
);
432 dev_err(&pdev
->dev
, "failed getting adc clock: %d\n", err
);
436 tsc_irq
= platform_get_irq(pdev
, 0);
438 dev_err(&pdev
->dev
, "no tsc irq resource?\n");
442 adc_irq
= platform_get_irq(pdev
, 1);
444 dev_err(&pdev
->dev
, "no adc irq resource?\n");
448 err
= devm_request_threaded_irq(tsc
->dev
, tsc_irq
,
449 NULL
, tsc_irq_fn
, IRQF_ONESHOT
,
450 dev_name(&pdev
->dev
), tsc
);
453 "failed requesting tsc irq %d: %d\n",
458 err
= devm_request_irq(tsc
->dev
, adc_irq
, adc_irq_fn
, 0,
459 dev_name(&pdev
->dev
), tsc
);
462 "failed requesting adc irq %d: %d\n",
467 err
= of_property_read_u32(np
, "measure-delay-time",
468 &tsc
->measure_delay_time
);
470 tsc
->measure_delay_time
= 0xffff;
472 err
= of_property_read_u32(np
, "pre-charge-time",
473 &tsc
->pre_charge_time
);
475 tsc
->pre_charge_time
= 0xfff;
477 err
= of_property_read_u32(np
, "touchscreen-average-samples",
482 switch (average_samples
) {
484 tsc
->average_enable
= false;
485 tsc
->average_select
= 0; /* value unused; initialize anyway */
491 tsc
->average_enable
= true;
492 tsc
->average_select
= ilog2(average_samples
) - 2;
496 "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n",
501 err
= input_register_device(tsc
->input
);
504 "failed to register input device: %d\n", err
);
508 platform_set_drvdata(pdev
, tsc
);
512 static int __maybe_unused
imx6ul_tsc_suspend(struct device
*dev
)
514 struct platform_device
*pdev
= to_platform_device(dev
);
515 struct imx6ul_tsc
*tsc
= platform_get_drvdata(pdev
);
516 struct input_dev
*input_dev
= tsc
->input
;
518 mutex_lock(&input_dev
->mutex
);
520 if (input_dev
->users
) {
521 imx6ul_tsc_disable(tsc
);
523 clk_disable_unprepare(tsc
->tsc_clk
);
524 clk_disable_unprepare(tsc
->adc_clk
);
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
= clk_prepare_enable(tsc
->adc_clk
);
546 retval
= clk_prepare_enable(tsc
->tsc_clk
);
548 clk_disable_unprepare(tsc
->adc_clk
);
552 retval
= imx6ul_tsc_init(tsc
);
556 mutex_unlock(&input_dev
->mutex
);
560 static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops
,
561 imx6ul_tsc_suspend
, imx6ul_tsc_resume
);
563 static const struct of_device_id imx6ul_tsc_match
[] = {
564 { .compatible
= "fsl,imx6ul-tsc", },
567 MODULE_DEVICE_TABLE(of
, imx6ul_tsc_match
);
569 static struct platform_driver imx6ul_tsc_driver
= {
571 .name
= "imx6ul-tsc",
572 .of_match_table
= imx6ul_tsc_match
,
573 .pm
= &imx6ul_tsc_pm_ops
,
575 .probe
= imx6ul_tsc_probe
,
577 module_platform_driver(imx6ul_tsc_driver
);
579 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
580 MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver");
581 MODULE_LICENSE("GPL v2");