1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TI Touch Screen / ADC MFD driver
4 *
5 * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/
6 */
7
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/err.h>
11 #include <linux/io.h>
12 #include <linux/clk.h>
13 #include <linux/regmap.h>
14 #include <linux/mfd/core.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/of.h>
17 #include <linux/platform_device.h>
18 #include <linux/sched.h>
19
20 #include <linux/mfd/ti_am335x_tscadc.h>
21
22 static const struct regmap_config tscadc_regmap_config = {
23 .name = "ti_tscadc",
24 .reg_bits = 32,
25 .reg_stride = 4,
26 .val_bits = 32,
27 };
28
am335x_tsc_se_set_cache(struct ti_tscadc_dev * tscadc,u32 val)29 void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tscadc, u32 val)
30 {
31 unsigned long flags;
32
33 spin_lock_irqsave(&tscadc->reg_lock, flags);
34 tscadc->reg_se_cache |= val;
35 if (tscadc->adc_waiting)
36 wake_up(&tscadc->reg_se_wait);
37 else if (!tscadc->adc_in_use)
38 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
39
40 spin_unlock_irqrestore(&tscadc->reg_lock, flags);
41 }
42 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
43
am335x_tscadc_need_adc(struct ti_tscadc_dev * tscadc)44 static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tscadc)
45 {
46 DEFINE_WAIT(wait);
47 u32 reg;
48
49 regmap_read(tscadc->regmap, REG_ADCFSM, ®);
50 if (reg & SEQ_STATUS) {
51 tscadc->adc_waiting = true;
52 prepare_to_wait(&tscadc->reg_se_wait, &wait,
53 TASK_UNINTERRUPTIBLE);
54 spin_unlock_irq(&tscadc->reg_lock);
55
56 schedule();
57
58 spin_lock_irq(&tscadc->reg_lock);
59 finish_wait(&tscadc->reg_se_wait, &wait);
60
61 /*
62 * Sequencer should either be idle or
63 * busy applying the charge step.
64 */
65 regmap_read(tscadc->regmap, REG_ADCFSM, ®);
66 WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP));
67 tscadc->adc_waiting = false;
68 }
69 tscadc->adc_in_use = true;
70 }
71
am335x_tsc_se_set_once(struct ti_tscadc_dev * tscadc,u32 val)72 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tscadc, u32 val)
73 {
74 spin_lock_irq(&tscadc->reg_lock);
75 am335x_tscadc_need_adc(tscadc);
76
77 regmap_write(tscadc->regmap, REG_SE, val);
78 spin_unlock_irq(&tscadc->reg_lock);
79 }
80 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
81
am335x_tsc_se_adc_done(struct ti_tscadc_dev * tscadc)82 void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tscadc)
83 {
84 unsigned long flags;
85
86 spin_lock_irqsave(&tscadc->reg_lock, flags);
87 tscadc->adc_in_use = false;
88 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
89 spin_unlock_irqrestore(&tscadc->reg_lock, flags);
90 }
91 EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
92
am335x_tsc_se_clr(struct ti_tscadc_dev * tscadc,u32 val)93 void am335x_tsc_se_clr(struct ti_tscadc_dev *tscadc, u32 val)
94 {
95 unsigned long flags;
96
97 spin_lock_irqsave(&tscadc->reg_lock, flags);
98 tscadc->reg_se_cache &= ~val;
99 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
100 spin_unlock_irqrestore(&tscadc->reg_lock, flags);
101 }
102 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
103
tscadc_idle_config(struct ti_tscadc_dev * tscadc)104 static void tscadc_idle_config(struct ti_tscadc_dev *tscadc)
105 {
106 unsigned int idleconfig;
107
108 idleconfig = STEPCONFIG_INM_ADCREFM | STEPCONFIG_INP_ADCREFM;
109 if (ti_adc_with_touchscreen(tscadc))
110 idleconfig |= STEPCONFIG_YNN | STEPCONFIG_YPN;
111
112 regmap_write(tscadc->regmap, REG_IDLECONFIG, idleconfig);
113 }
114
ti_tscadc_probe(struct platform_device * pdev)115 static int ti_tscadc_probe(struct platform_device *pdev)
116 {
117 struct ti_tscadc_dev *tscadc;
118 struct resource *res;
119 struct clk *clk;
120 struct device_node *node;
121 struct mfd_cell *cell;
122 bool use_tsc = false, use_mag = false;
123 u32 val;
124 int err;
125 int tscmag_wires = 0, adc_channels = 0, cell_idx = 0, total_channels;
126 int readouts = 0, mag_tracks = 0;
127
128 /* Allocate memory for device */
129 tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL);
130 if (!tscadc)
131 return -ENOMEM;
132
133 tscadc->dev = &pdev->dev;
134
135 if (!pdev->dev.of_node) {
136 dev_err(&pdev->dev, "Could not find valid DT data.\n");
137 return -EINVAL;
138 }
139
140 tscadc->data = of_device_get_match_data(&pdev->dev);
141
142 if (ti_adc_with_touchscreen(tscadc)) {
143 node = of_get_child_by_name(pdev->dev.of_node, "tsc");
144 of_property_read_u32(node, "ti,wires", &tscmag_wires);
145 err = of_property_read_u32(node, "ti,coordinate-readouts",
146 &readouts);
147 if (err < 0)
148 of_property_read_u32(node, "ti,coordiante-readouts",
149 &readouts);
150
151 of_node_put(node);
152
153 if (tscmag_wires)
154 use_tsc = true;
155 } else {
156 /*
157 * When adding support for the magnetic stripe reader, here is
158 * the place to look for the number of tracks used from device
159 * tree. Let's default to 0 for now.
160 */
161 mag_tracks = 0;
162 tscmag_wires = mag_tracks * 2;
163 if (tscmag_wires)
164 use_mag = true;
165 }
166
167 node = of_get_child_by_name(pdev->dev.of_node, "adc");
168 of_property_for_each_u32(node, "ti,adc-channels", val) {
169 adc_channels++;
170 if (val > 7) {
171 dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
172 val);
173 of_node_put(node);
174 return -EINVAL;
175 }
176 }
177
178 of_node_put(node);
179
180 total_channels = tscmag_wires + adc_channels;
181 if (total_channels > 8) {
182 dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
183 return -EINVAL;
184 }
185
186 if (total_channels == 0) {
187 dev_err(&pdev->dev, "Need at least one channel.\n");
188 return -EINVAL;
189 }
190
191 if (use_tsc && (readouts * 2 + 2 + adc_channels > 16)) {
192 dev_err(&pdev->dev, "Too many step configurations requested\n");
193 return -EINVAL;
194 }
195
196 err = platform_get_irq(pdev, 0);
197 if (err < 0)
198 return err;
199 else
200 tscadc->irq = err;
201
202 tscadc->tscadc_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
203 if (IS_ERR(tscadc->tscadc_base))
204 return PTR_ERR(tscadc->tscadc_base);
205
206 tscadc->tscadc_phys_base = res->start;
207 tscadc->regmap = devm_regmap_init_mmio(&pdev->dev,
208 tscadc->tscadc_base,
209 &tscadc_regmap_config);
210 if (IS_ERR(tscadc->regmap)) {
211 dev_err(&pdev->dev, "regmap init failed\n");
212 return PTR_ERR(tscadc->regmap);
213 }
214
215 spin_lock_init(&tscadc->reg_lock);
216 init_waitqueue_head(&tscadc->reg_se_wait);
217
218 pm_runtime_enable(&pdev->dev);
219 pm_runtime_get_sync(&pdev->dev);
220
221 /*
222 * The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK.
223 * ADCs produce a 12-bit sample every 15 ADC_CLK cycles.
224 * am33xx ADCs expect to capture 200ksps.
225 * am47xx ADCs expect to capture 867ksps.
226 * We need ADC clocks respectively running at 3MHz and 13MHz.
227 * These frequencies are valid since TSC_ADC_SS controller design
228 * assumes the OCP clock is at least 6x faster than the ADC clock.
229 */
230 clk = devm_clk_get(&pdev->dev, NULL);
231 if (IS_ERR(clk)) {
232 dev_err(&pdev->dev, "failed to get fck\n");
233 err = PTR_ERR(clk);
234 goto err_disable_clk;
235 }
236
237 tscadc->clk_div = (clk_get_rate(clk) / tscadc->data->target_clk_rate) - 1;
238 regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
239
240 /*
241 * Set the control register bits. tscadc->ctrl stores the configuration
242 * of the CTRL register but not the subsystem enable bit which must be
243 * added manually when timely.
244 */
245 tscadc->ctrl = CNTRLREG_STEPID;
246 if (ti_adc_with_touchscreen(tscadc)) {
247 tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT;
248 if (use_tsc) {
249 tscadc->ctrl |= CNTRLREG_TSC_ENB;
250 if (tscmag_wires == 5)
251 tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
252 else
253 tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
254 }
255 } else {
256 tscadc->ctrl |= CNTRLREG_MAG_PREAMP_PWRDOWN |
257 CNTRLREG_MAG_PREAMP_BYPASS;
258 }
259 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
260
261 tscadc_idle_config(tscadc);
262
263 /* Enable the TSC module enable bit */
264 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB);
265
266 /* TSC or MAG Cell */
267 if (use_tsc || use_mag) {
268 cell = &tscadc->cells[cell_idx++];
269 cell->name = tscadc->data->secondary_feature_name;
270 cell->of_compatible = tscadc->data->secondary_feature_compatible;
271 cell->platform_data = &tscadc;
272 cell->pdata_size = sizeof(tscadc);
273 }
274
275 /* ADC Cell */
276 if (adc_channels > 0) {
277 cell = &tscadc->cells[cell_idx++];
278 cell->name = tscadc->data->adc_feature_name;
279 cell->of_compatible = tscadc->data->adc_feature_compatible;
280 cell->platform_data = &tscadc;
281 cell->pdata_size = sizeof(tscadc);
282 }
283
284 err = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
285 tscadc->cells, cell_idx, NULL, 0, NULL);
286 if (err < 0)
287 goto err_disable_clk;
288
289 platform_set_drvdata(pdev, tscadc);
290 return 0;
291
292 err_disable_clk:
293 pm_runtime_put_sync(&pdev->dev);
294 pm_runtime_disable(&pdev->dev);
295
296 return err;
297 }
298
ti_tscadc_remove(struct platform_device * pdev)299 static void ti_tscadc_remove(struct platform_device *pdev)
300 {
301 struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);
302
303 regmap_write(tscadc->regmap, REG_SE, 0x00);
304
305 pm_runtime_put_sync(&pdev->dev);
306 pm_runtime_disable(&pdev->dev);
307
308 mfd_remove_devices(tscadc->dev);
309 }
310
ti_tscadc_can_wakeup(struct device * dev,void * data)311 static int __maybe_unused ti_tscadc_can_wakeup(struct device *dev, void *data)
312 {
313 return device_may_wakeup(dev);
314 }
315
tscadc_suspend(struct device * dev)316 static int __maybe_unused tscadc_suspend(struct device *dev)
317 {
318 struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev);
319
320 regmap_write(tscadc->regmap, REG_SE, 0x00);
321 if (device_for_each_child(dev, NULL, ti_tscadc_can_wakeup)) {
322 u32 ctrl;
323
324 regmap_read(tscadc->regmap, REG_CTRL, &ctrl);
325 ctrl &= ~(CNTRLREG_POWERDOWN);
326 ctrl |= CNTRLREG_SSENB;
327 regmap_write(tscadc->regmap, REG_CTRL, ctrl);
328 }
329 pm_runtime_put_sync(dev);
330
331 return 0;
332 }
333
tscadc_resume(struct device * dev)334 static int __maybe_unused tscadc_resume(struct device *dev)
335 {
336 struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev);
337
338 pm_runtime_get_sync(dev);
339
340 regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
341 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
342 tscadc_idle_config(tscadc);
343 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB);
344
345 return 0;
346 }
347
348 static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume);
349
350 static const struct ti_tscadc_data tscdata = {
351 .adc_feature_name = "TI-am335x-adc",
352 .adc_feature_compatible = "ti,am3359-adc",
353 .secondary_feature_name = "TI-am335x-tsc",
354 .secondary_feature_compatible = "ti,am3359-tsc",
355 .target_clk_rate = TSC_ADC_CLK,
356 };
357
358 static const struct ti_tscadc_data magdata = {
359 .adc_feature_name = "TI-am43xx-adc",
360 .adc_feature_compatible = "ti,am4372-adc",
361 .secondary_feature_name = "TI-am43xx-mag",
362 .secondary_feature_compatible = "ti,am4372-mag",
363 .target_clk_rate = MAG_ADC_CLK,
364 };
365
366 static const struct of_device_id ti_tscadc_dt_ids[] = {
367 { .compatible = "ti,am3359-tscadc", .data = &tscdata },
368 { .compatible = "ti,am4372-magadc", .data = &magdata },
369 { }
370 };
371 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
372
373 static struct platform_driver ti_tscadc_driver = {
374 .driver = {
375 .name = "ti_am3359-tscadc",
376 .pm = &tscadc_pm_ops,
377 .of_match_table = ti_tscadc_dt_ids,
378 },
379 .probe = ti_tscadc_probe,
380 .remove_new = ti_tscadc_remove,
381
382 };
383
384 module_platform_driver(ti_tscadc_driver);
385
386 MODULE_DESCRIPTION("TI touchscreen/magnetic stripe reader/ADC MFD controller driver");
387 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
388 MODULE_LICENSE("GPL");
389