1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * NXP i.MX8QXP ADC driver
4 *
5 * Based on the work of Haibo Chen <haibo.chen@nxp.com>
6 * The initial developer of the original code is Haibo Chen.
7 * Portions created by Haibo Chen are Copyright (C) 2018 NXP.
8 * All Rights Reserved.
9 *
10 * Copyright (C) 2018 NXP
11 * Copyright (C) 2021 Cai Huoqing
12 */
13 #include <linux/bitfield.h>
14 #include <linux/bits.h>
15 #include <linux/clk.h>
16 #include <linux/completion.h>
17 #include <linux/delay.h>
18 #include <linux/err.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/mod_devicetable.h>
23 #include <linux/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/regulator/consumer.h>
27
28 #include <linux/iio/iio.h>
29
30 #define ADC_DRIVER_NAME "imx8qxp-adc"
31
32 /* Register map definition */
33 #define IMX8QXP_ADR_ADC_CTRL 0x10
34 #define IMX8QXP_ADR_ADC_STAT 0x14
35 #define IMX8QXP_ADR_ADC_IE 0x18
36 #define IMX8QXP_ADR_ADC_DE 0x1c
37 #define IMX8QXP_ADR_ADC_CFG 0x20
38 #define IMX8QXP_ADR_ADC_FCTRL 0x30
39 #define IMX8QXP_ADR_ADC_SWTRIG 0x34
40 #define IMX8QXP_ADR_ADC_TCTRL(tid) (0xc0 + (tid) * 4)
41 #define IMX8QXP_ADR_ADC_CMDL(cid) (0x100 + (cid) * 8)
42 #define IMX8QXP_ADR_ADC_CMDH(cid) (0x104 + (cid) * 8)
43 #define IMX8QXP_ADR_ADC_RESFIFO 0x300
44 #define IMX8QXP_ADR_ADC_TST 0xffc
45
46 /* ADC bit shift */
47 #define IMX8QXP_ADC_IE_FWMIE_MASK GENMASK(1, 0)
48 #define IMX8QXP_ADC_CTRL_FIFO_RESET_MASK BIT(8)
49 #define IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK BIT(1)
50 #define IMX8QXP_ADC_CTRL_ADC_EN_MASK BIT(0)
51 #define IMX8QXP_ADC_TCTRL_TCMD_MASK GENMASK(31, 24)
52 #define IMX8QXP_ADC_TCTRL_TDLY_MASK GENMASK(23, 16)
53 #define IMX8QXP_ADC_TCTRL_TPRI_MASK GENMASK(15, 8)
54 #define IMX8QXP_ADC_TCTRL_HTEN_MASK GENMASK(7, 0)
55 #define IMX8QXP_ADC_CMDL_CSCALE_MASK GENMASK(13, 8)
56 #define IMX8QXP_ADC_CMDL_MODE_MASK BIT(7)
57 #define IMX8QXP_ADC_CMDL_DIFF_MASK BIT(6)
58 #define IMX8QXP_ADC_CMDL_ABSEL_MASK BIT(5)
59 #define IMX8QXP_ADC_CMDL_ADCH_MASK GENMASK(2, 0)
60 #define IMX8QXP_ADC_CMDH_NEXT_MASK GENMASK(31, 24)
61 #define IMX8QXP_ADC_CMDH_LOOP_MASK GENMASK(23, 16)
62 #define IMX8QXP_ADC_CMDH_AVGS_MASK GENMASK(15, 12)
63 #define IMX8QXP_ADC_CMDH_STS_MASK BIT(8)
64 #define IMX8QXP_ADC_CMDH_LWI_MASK GENMASK(7, 7)
65 #define IMX8QXP_ADC_CMDH_CMPEN_MASK GENMASK(0, 0)
66 #define IMX8QXP_ADC_CFG_PWREN_MASK BIT(28)
67 #define IMX8QXP_ADC_CFG_PUDLY_MASK GENMASK(23, 16)
68 #define IMX8QXP_ADC_CFG_REFSEL_MASK GENMASK(7, 6)
69 #define IMX8QXP_ADC_CFG_PWRSEL_MASK GENMASK(5, 4)
70 #define IMX8QXP_ADC_CFG_TPRICTRL_MASK GENMASK(3, 0)
71 #define IMX8QXP_ADC_FCTRL_FWMARK_MASK GENMASK(20, 16)
72 #define IMX8QXP_ADC_FCTRL_FCOUNT_MASK GENMASK(4, 0)
73 #define IMX8QXP_ADC_RESFIFO_VAL_MASK GENMASK(18, 3)
74
75 /* ADC PARAMETER*/
76 #define IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL GENMASK(5, 0)
77 #define IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL 0
78 #define IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION 0
79 #define IMX8QXP_ADC_CMDL_MODE_SINGLE 0
80 #define IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS 0
81 #define IMX8QXP_ADC_CMDH_CMPEN_DIS 0
82 #define IMX8QXP_ADC_PAUSE_EN BIT(31)
83 #define IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH 0
84
85 #define IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS 0
86
87 #define IMX8QXP_ADC_TIMEOUT msecs_to_jiffies(100)
88
89 #define IMX8QXP_ADC_MAX_FIFO_SIZE 16
90
91 struct imx8qxp_adc {
92 struct device *dev;
93 void __iomem *regs;
94 struct clk *clk;
95 struct clk *ipg_clk;
96 struct regulator *vref;
97 /* Serialise ADC channel reads */
98 struct mutex lock;
99 struct completion completion;
100 u32 fifo[IMX8QXP_ADC_MAX_FIFO_SIZE];
101 };
102
103 #define IMX8QXP_ADC_CHAN(_idx) { \
104 .type = IIO_VOLTAGE, \
105 .indexed = 1, \
106 .channel = (_idx), \
107 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
108 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
109 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
110 }
111
112 static const struct iio_chan_spec imx8qxp_adc_iio_channels[] = {
113 IMX8QXP_ADC_CHAN(0),
114 IMX8QXP_ADC_CHAN(1),
115 IMX8QXP_ADC_CHAN(2),
116 IMX8QXP_ADC_CHAN(3),
117 IMX8QXP_ADC_CHAN(4),
118 IMX8QXP_ADC_CHAN(5),
119 IMX8QXP_ADC_CHAN(6),
120 IMX8QXP_ADC_CHAN(7),
121 };
122
imx8qxp_adc_reset(struct imx8qxp_adc * adc)123 static void imx8qxp_adc_reset(struct imx8qxp_adc *adc)
124 {
125 u32 ctrl;
126
127 /*software reset, need to clear the set bit*/
128 ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
129 ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
130 writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
131 udelay(10);
132 ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
133 writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
134
135 /* reset the fifo */
136 ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_FIFO_RESET_MASK, 1);
137 writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
138 }
139
imx8qxp_adc_reg_config(struct imx8qxp_adc * adc,int channel)140 static void imx8qxp_adc_reg_config(struct imx8qxp_adc *adc, int channel)
141 {
142 u32 adc_cfg, adc_tctrl, adc_cmdl, adc_cmdh;
143
144 /* ADC configuration */
145 adc_cfg = FIELD_PREP(IMX8QXP_ADC_CFG_PWREN_MASK, 1) |
146 FIELD_PREP(IMX8QXP_ADC_CFG_PUDLY_MASK, 0x80)|
147 FIELD_PREP(IMX8QXP_ADC_CFG_REFSEL_MASK, 0) |
148 FIELD_PREP(IMX8QXP_ADC_CFG_PWRSEL_MASK, 3) |
149 FIELD_PREP(IMX8QXP_ADC_CFG_TPRICTRL_MASK, 0);
150 writel(adc_cfg, adc->regs + IMX8QXP_ADR_ADC_CFG);
151
152 /* config the trigger control */
153 adc_tctrl = FIELD_PREP(IMX8QXP_ADC_TCTRL_TCMD_MASK, 1) |
154 FIELD_PREP(IMX8QXP_ADC_TCTRL_TDLY_MASK, 0) |
155 FIELD_PREP(IMX8QXP_ADC_TCTRL_TPRI_MASK, IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH) |
156 FIELD_PREP(IMX8QXP_ADC_TCTRL_HTEN_MASK, IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS);
157 writel(adc_tctrl, adc->regs + IMX8QXP_ADR_ADC_TCTRL(0));
158
159 /* config the cmd */
160 adc_cmdl = FIELD_PREP(IMX8QXP_ADC_CMDL_CSCALE_MASK, IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL) |
161 FIELD_PREP(IMX8QXP_ADC_CMDL_MODE_MASK, IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION) |
162 FIELD_PREP(IMX8QXP_ADC_CMDL_DIFF_MASK, IMX8QXP_ADC_CMDL_MODE_SINGLE) |
163 FIELD_PREP(IMX8QXP_ADC_CMDL_ABSEL_MASK, IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL) |
164 FIELD_PREP(IMX8QXP_ADC_CMDL_ADCH_MASK, channel);
165 writel(adc_cmdl, adc->regs + IMX8QXP_ADR_ADC_CMDL(0));
166
167 adc_cmdh = FIELD_PREP(IMX8QXP_ADC_CMDH_NEXT_MASK, 0) |
168 FIELD_PREP(IMX8QXP_ADC_CMDH_LOOP_MASK, 0) |
169 FIELD_PREP(IMX8QXP_ADC_CMDH_AVGS_MASK, 7) |
170 FIELD_PREP(IMX8QXP_ADC_CMDH_STS_MASK, 0) |
171 FIELD_PREP(IMX8QXP_ADC_CMDH_LWI_MASK, IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS) |
172 FIELD_PREP(IMX8QXP_ADC_CMDH_CMPEN_MASK, IMX8QXP_ADC_CMDH_CMPEN_DIS);
173 writel(adc_cmdh, adc->regs + IMX8QXP_ADR_ADC_CMDH(0));
174 }
175
imx8qxp_adc_fifo_config(struct imx8qxp_adc * adc)176 static void imx8qxp_adc_fifo_config(struct imx8qxp_adc *adc)
177 {
178 u32 fifo_ctrl, interrupt_en;
179
180 fifo_ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL);
181 fifo_ctrl &= ~IMX8QXP_ADC_FCTRL_FWMARK_MASK;
182 /* set the watermark level to 1 */
183 fifo_ctrl |= FIELD_PREP(IMX8QXP_ADC_FCTRL_FWMARK_MASK, 0);
184 writel(fifo_ctrl, adc->regs + IMX8QXP_ADR_ADC_FCTRL);
185
186 /* FIFO Watermark Interrupt Enable */
187 interrupt_en = readl(adc->regs + IMX8QXP_ADR_ADC_IE);
188 interrupt_en |= FIELD_PREP(IMX8QXP_ADC_IE_FWMIE_MASK, 1);
189 writel(interrupt_en, adc->regs + IMX8QXP_ADR_ADC_IE);
190 }
191
imx8qxp_adc_disable(struct imx8qxp_adc * adc)192 static void imx8qxp_adc_disable(struct imx8qxp_adc *adc)
193 {
194 u32 ctrl;
195
196 ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
197 ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
198 writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
199 }
200
imx8qxp_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)201 static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev,
202 struct iio_chan_spec const *chan,
203 int *val, int *val2, long mask)
204 {
205 struct imx8qxp_adc *adc = iio_priv(indio_dev);
206 struct device *dev = adc->dev;
207
208 u32 ctrl;
209 long ret;
210
211 switch (mask) {
212 case IIO_CHAN_INFO_RAW:
213 pm_runtime_get_sync(dev);
214
215 mutex_lock(&adc->lock);
216 reinit_completion(&adc->completion);
217
218 imx8qxp_adc_reg_config(adc, chan->channel);
219
220 imx8qxp_adc_fifo_config(adc);
221
222 /* adc enable */
223 ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
224 ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
225 writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
226 /* adc start */
227 writel(1, adc->regs + IMX8QXP_ADR_ADC_SWTRIG);
228
229 ret = wait_for_completion_interruptible_timeout(&adc->completion,
230 IMX8QXP_ADC_TIMEOUT);
231
232 pm_runtime_put_sync_autosuspend(dev);
233
234 if (ret == 0) {
235 mutex_unlock(&adc->lock);
236 return -ETIMEDOUT;
237 }
238 if (ret < 0) {
239 mutex_unlock(&adc->lock);
240 return ret;
241 }
242
243 *val = adc->fifo[0];
244
245 mutex_unlock(&adc->lock);
246 return IIO_VAL_INT;
247
248 case IIO_CHAN_INFO_SCALE:
249 ret = regulator_get_voltage(adc->vref);
250 if (ret < 0)
251 return ret;
252 *val = ret / 1000;
253 *val2 = 12;
254 return IIO_VAL_FRACTIONAL_LOG2;
255
256 case IIO_CHAN_INFO_SAMP_FREQ:
257 *val = clk_get_rate(adc->clk) / 3;
258 return IIO_VAL_INT;
259
260 default:
261 return -EINVAL;
262 }
263 }
264
imx8qxp_adc_isr(int irq,void * dev_id)265 static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
266 {
267 struct imx8qxp_adc *adc = dev_id;
268 u32 fifo_count;
269 int i;
270
271 fifo_count = FIELD_GET(IMX8QXP_ADC_FCTRL_FCOUNT_MASK,
272 readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL));
273
274 for (i = 0; i < fifo_count; i++)
275 adc->fifo[i] = FIELD_GET(IMX8QXP_ADC_RESFIFO_VAL_MASK,
276 readl_relaxed(adc->regs + IMX8QXP_ADR_ADC_RESFIFO));
277
278 if (fifo_count)
279 complete(&adc->completion);
280
281 return IRQ_HANDLED;
282 }
283
imx8qxp_adc_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)284 static int imx8qxp_adc_reg_access(struct iio_dev *indio_dev, unsigned int reg,
285 unsigned int writeval, unsigned int *readval)
286 {
287 struct imx8qxp_adc *adc = iio_priv(indio_dev);
288 struct device *dev = adc->dev;
289
290 if (!readval || reg % 4 || reg > IMX8QXP_ADR_ADC_TST)
291 return -EINVAL;
292
293 pm_runtime_get_sync(dev);
294
295 *readval = readl(adc->regs + reg);
296
297 pm_runtime_put_sync_autosuspend(dev);
298
299 return 0;
300 }
301
302 static const struct iio_info imx8qxp_adc_iio_info = {
303 .read_raw = &imx8qxp_adc_read_raw,
304 .debugfs_reg_access = &imx8qxp_adc_reg_access,
305 };
306
imx8qxp_adc_probe(struct platform_device * pdev)307 static int imx8qxp_adc_probe(struct platform_device *pdev)
308 {
309 struct imx8qxp_adc *adc;
310 struct iio_dev *indio_dev;
311 struct device *dev = &pdev->dev;
312 int irq;
313 int ret;
314
315 indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
316 if (!indio_dev)
317 return -ENOMEM;
318
319 adc = iio_priv(indio_dev);
320 adc->dev = dev;
321
322 mutex_init(&adc->lock);
323 adc->regs = devm_platform_ioremap_resource(pdev, 0);
324 if (IS_ERR(adc->regs))
325 return PTR_ERR(adc->regs);
326
327 irq = platform_get_irq(pdev, 0);
328 if (irq < 0)
329 return irq;
330
331 adc->clk = devm_clk_get(dev, "per");
332 if (IS_ERR(adc->clk))
333 return dev_err_probe(dev, PTR_ERR(adc->clk), "Failed getting clock\n");
334
335 adc->ipg_clk = devm_clk_get(dev, "ipg");
336 if (IS_ERR(adc->ipg_clk))
337 return dev_err_probe(dev, PTR_ERR(adc->ipg_clk), "Failed getting clock\n");
338
339 adc->vref = devm_regulator_get(dev, "vref");
340 if (IS_ERR(adc->vref))
341 return dev_err_probe(dev, PTR_ERR(adc->vref), "Failed getting reference voltage\n");
342
343 ret = regulator_enable(adc->vref);
344 if (ret) {
345 dev_err(dev, "Can't enable adc reference top voltage\n");
346 return ret;
347 }
348
349 platform_set_drvdata(pdev, indio_dev);
350
351 init_completion(&adc->completion);
352
353 indio_dev->name = ADC_DRIVER_NAME;
354 indio_dev->info = &imx8qxp_adc_iio_info;
355 indio_dev->modes = INDIO_DIRECT_MODE;
356 indio_dev->channels = imx8qxp_adc_iio_channels;
357 indio_dev->num_channels = ARRAY_SIZE(imx8qxp_adc_iio_channels);
358
359 ret = clk_prepare_enable(adc->clk);
360 if (ret) {
361 dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
362 goto error_regulator_disable;
363 }
364
365 ret = clk_prepare_enable(adc->ipg_clk);
366 if (ret) {
367 dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
368 goto error_adc_clk_disable;
369 }
370
371 ret = devm_request_irq(dev, irq, imx8qxp_adc_isr, 0, ADC_DRIVER_NAME, adc);
372 if (ret < 0) {
373 dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
374 goto error_ipg_clk_disable;
375 }
376
377 imx8qxp_adc_reset(adc);
378
379 ret = iio_device_register(indio_dev);
380 if (ret) {
381 imx8qxp_adc_disable(adc);
382 dev_err(dev, "Couldn't register the device.\n");
383 goto error_ipg_clk_disable;
384 }
385
386 pm_runtime_set_active(dev);
387 pm_runtime_set_autosuspend_delay(dev, 50);
388 pm_runtime_use_autosuspend(dev);
389 pm_runtime_enable(dev);
390
391 return 0;
392
393 error_ipg_clk_disable:
394 clk_disable_unprepare(adc->ipg_clk);
395 error_adc_clk_disable:
396 clk_disable_unprepare(adc->clk);
397 error_regulator_disable:
398 regulator_disable(adc->vref);
399
400 return ret;
401 }
402
imx8qxp_adc_remove(struct platform_device * pdev)403 static void imx8qxp_adc_remove(struct platform_device *pdev)
404 {
405 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
406 struct imx8qxp_adc *adc = iio_priv(indio_dev);
407 struct device *dev = adc->dev;
408
409 pm_runtime_get_sync(dev);
410
411 iio_device_unregister(indio_dev);
412
413 imx8qxp_adc_disable(adc);
414
415 clk_disable_unprepare(adc->clk);
416 clk_disable_unprepare(adc->ipg_clk);
417 regulator_disable(adc->vref);
418
419 pm_runtime_disable(dev);
420 pm_runtime_put_noidle(dev);
421 }
422
imx8qxp_adc_runtime_suspend(struct device * dev)423 static int imx8qxp_adc_runtime_suspend(struct device *dev)
424 {
425 struct iio_dev *indio_dev = dev_get_drvdata(dev);
426 struct imx8qxp_adc *adc = iio_priv(indio_dev);
427
428 imx8qxp_adc_disable(adc);
429
430 clk_disable_unprepare(adc->clk);
431 clk_disable_unprepare(adc->ipg_clk);
432 regulator_disable(adc->vref);
433
434 return 0;
435 }
436
imx8qxp_adc_runtime_resume(struct device * dev)437 static int imx8qxp_adc_runtime_resume(struct device *dev)
438 {
439 struct iio_dev *indio_dev = dev_get_drvdata(dev);
440 struct imx8qxp_adc *adc = iio_priv(indio_dev);
441 int ret;
442
443 ret = regulator_enable(adc->vref);
444 if (ret) {
445 dev_err(dev, "Can't enable adc reference top voltage, err = %d\n", ret);
446 return ret;
447 }
448
449 ret = clk_prepare_enable(adc->clk);
450 if (ret) {
451 dev_err(dev, "Could not prepare or enable clock.\n");
452 goto err_disable_reg;
453 }
454
455 ret = clk_prepare_enable(adc->ipg_clk);
456 if (ret) {
457 dev_err(dev, "Could not prepare or enable clock.\n");
458 goto err_unprepare_clk;
459 }
460
461 imx8qxp_adc_reset(adc);
462
463 return 0;
464
465 err_unprepare_clk:
466 clk_disable_unprepare(adc->clk);
467
468 err_disable_reg:
469 regulator_disable(adc->vref);
470
471 return ret;
472 }
473
474 static DEFINE_RUNTIME_DEV_PM_OPS(imx8qxp_adc_pm_ops,
475 imx8qxp_adc_runtime_suspend,
476 imx8qxp_adc_runtime_resume, NULL);
477
478 static const struct of_device_id imx8qxp_adc_match[] = {
479 { .compatible = "nxp,imx8qxp-adc", },
480 { }
481 };
482 MODULE_DEVICE_TABLE(of, imx8qxp_adc_match);
483
484 static struct platform_driver imx8qxp_adc_driver = {
485 .probe = imx8qxp_adc_probe,
486 .remove = imx8qxp_adc_remove,
487 .driver = {
488 .name = ADC_DRIVER_NAME,
489 .of_match_table = imx8qxp_adc_match,
490 .pm = pm_ptr(&imx8qxp_adc_pm_ops),
491 },
492 };
493
494 module_platform_driver(imx8qxp_adc_driver);
495
496 MODULE_DESCRIPTION("i.MX8QuadXPlus ADC driver");
497 MODULE_LICENSE("GPL v2");
498