1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Synopsys DesignWare I2C adapter driver.
4 *
5 * Based on the TI DAVINCI I2C adapter driver.
6 *
7 * Copyright (C) 2006 Texas Instruments.
8 * Copyright (C) 2007 MontaVista Software Inc.
9 * Copyright (C) 2009 Provigent Ltd.
10 */
11 #include <linux/acpi.h>
12 #include <linux/clk-provider.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/dmi.h>
16 #include <linux/err.h>
17 #include <linux/errno.h>
18 #include <linux/i2c.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/platform_data/i2c-designware.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/property.h>
29 #include <linux/reset.h>
30 #include <linux/sched.h>
31 #include <linux/slab.h>
32 #include <linux/suspend.h>
33
34 #include "i2c-designware-core.h"
35
i2c_dw_get_clk_rate_khz(struct dw_i2c_dev * dev)36 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
37 {
38 return clk_get_rate(dev->clk)/1000;
39 }
40
41 #ifdef CONFIG_ACPI
42 /*
43 * The HCNT/LCNT information coming from ACPI should be the most accurate
44 * for given platform. However, some systems get it wrong. On such systems
45 * we get better results by calculating those based on the input clock.
46 */
47 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
48 {
49 .ident = "Dell Inspiron 7348",
50 .matches = {
51 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
52 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
53 },
54 },
55 { }
56 };
57
dw_i2c_acpi_params(struct platform_device * pdev,char method[],u16 * hcnt,u16 * lcnt,u32 * sda_hold)58 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
59 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
60 {
61 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
62 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
63 union acpi_object *obj;
64
65 if (dmi_check_system(dw_i2c_no_acpi_params))
66 return;
67
68 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
69 return;
70
71 obj = (union acpi_object *)buf.pointer;
72 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
73 const union acpi_object *objs = obj->package.elements;
74
75 *hcnt = (u16)objs[0].integer.value;
76 *lcnt = (u16)objs[1].integer.value;
77 *sda_hold = (u32)objs[2].integer.value;
78 }
79
80 kfree(buf.pointer);
81 }
82
dw_i2c_acpi_configure(struct platform_device * pdev)83 static int dw_i2c_acpi_configure(struct platform_device *pdev)
84 {
85 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
86 struct i2c_timings *t = &dev->timings;
87 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
88 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
89 const struct acpi_device_id *id;
90 struct acpi_device *adev;
91 const char *uid;
92
93 dev->adapter.nr = -1;
94 dev->tx_fifo_depth = 32;
95 dev->rx_fifo_depth = 32;
96
97 /*
98 * Try to get SDA hold time and *CNT values from an ACPI method for
99 * selected speed modes.
100 */
101 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
102 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
103 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
104 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
105
106 switch (t->bus_freq_hz) {
107 case 100000:
108 dev->sda_hold_time = ss_ht;
109 break;
110 case 1000000:
111 dev->sda_hold_time = fp_ht;
112 break;
113 case 3400000:
114 dev->sda_hold_time = hs_ht;
115 break;
116 case 400000:
117 default:
118 dev->sda_hold_time = fs_ht;
119 break;
120 }
121
122 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
123 if (id && id->driver_data)
124 dev->flags |= (u32)id->driver_data;
125
126 if (acpi_bus_get_device(handle, &adev))
127 return -ENODEV;
128
129 /*
130 * Cherrytrail I2C7 gets used for the PMIC which gets accessed
131 * through ACPI opregions during late suspend / early resume
132 * disable pm for it.
133 */
134 uid = adev->pnp.unique_id;
135 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
136 dev->pm_disabled = true;
137
138 return 0;
139 }
140
141 static const struct acpi_device_id dw_i2c_acpi_match[] = {
142 { "INT33C2", 0 },
143 { "INT33C3", 0 },
144 { "INT3432", 0 },
145 { "INT3433", 0 },
146 { "80860F41", 0 },
147 { "808622C1", MODEL_CHERRYTRAIL },
148 { "AMD0010", ACCESS_INTR_MASK },
149 { "AMDI0010", ACCESS_INTR_MASK },
150 { "AMDI0510", 0 },
151 { "APMC0D0F", 0 },
152 { "HISI02A1", 0 },
153 { "HISI02A2", 0 },
154 { }
155 };
156 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
157 #else
dw_i2c_acpi_configure(struct platform_device * pdev)158 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
159 {
160 return -ENODEV;
161 }
162 #endif
163
i2c_dw_configure_master(struct dw_i2c_dev * dev)164 static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
165 {
166 struct i2c_timings *t = &dev->timings;
167
168 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
169
170 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
171 DW_IC_CON_RESTART_EN;
172
173 dev->mode = DW_IC_MASTER;
174
175 switch (t->bus_freq_hz) {
176 case 100000:
177 dev->master_cfg |= DW_IC_CON_SPEED_STD;
178 break;
179 case 3400000:
180 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
181 break;
182 default:
183 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
184 }
185 }
186
i2c_dw_configure_slave(struct dw_i2c_dev * dev)187 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
188 {
189 dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY;
190
191 dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
192 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED;
193
194 dev->mode = DW_IC_SLAVE;
195 }
196
dw_i2c_set_fifo_size(struct dw_i2c_dev * dev,int id)197 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
198 {
199 u32 param, tx_fifo_depth, rx_fifo_depth;
200
201 /*
202 * Try to detect the FIFO depth if not set by interface driver,
203 * the depth could be from 2 to 256 from HW spec.
204 */
205 param = i2c_dw_read_comp_param(dev);
206 tx_fifo_depth = ((param >> 16) & 0xff) + 1;
207 rx_fifo_depth = ((param >> 8) & 0xff) + 1;
208 if (!dev->tx_fifo_depth) {
209 dev->tx_fifo_depth = tx_fifo_depth;
210 dev->rx_fifo_depth = rx_fifo_depth;
211 dev->adapter.nr = id;
212 } else if (tx_fifo_depth >= 2) {
213 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
214 tx_fifo_depth);
215 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
216 rx_fifo_depth);
217 }
218 }
219
dw_i2c_plat_pm_cleanup(struct dw_i2c_dev * dev)220 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
221 {
222 pm_runtime_disable(dev->dev);
223
224 if (dev->pm_disabled)
225 pm_runtime_put_noidle(dev->dev);
226 }
227
dw_i2c_plat_probe(struct platform_device * pdev)228 static int dw_i2c_plat_probe(struct platform_device *pdev)
229 {
230 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
231 struct i2c_adapter *adap;
232 struct dw_i2c_dev *dev;
233 struct i2c_timings *t;
234 u32 acpi_speed;
235 struct resource *mem;
236 int i, irq, ret;
237 static const int supported_speeds[] = {
238 0, 100000, 400000, 1000000, 3400000
239 };
240
241 irq = platform_get_irq(pdev, 0);
242 if (irq < 0)
243 return irq;
244
245 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
246 if (!dev)
247 return -ENOMEM;
248
249 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
250 dev->base = devm_ioremap_resource(&pdev->dev, mem);
251 if (IS_ERR(dev->base))
252 return PTR_ERR(dev->base);
253
254 dev->dev = &pdev->dev;
255 dev->irq = irq;
256 platform_set_drvdata(pdev, dev);
257
258 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
259 if (IS_ERR(dev->rst)) {
260 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
261 return -EPROBE_DEFER;
262 } else {
263 reset_control_deassert(dev->rst);
264 }
265
266 t = &dev->timings;
267 if (pdata)
268 t->bus_freq_hz = pdata->i2c_scl_freq;
269 else
270 i2c_parse_fw_timings(&pdev->dev, t, false);
271
272 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
273 /*
274 * Some DSTDs use a non standard speed, round down to the lowest
275 * standard speed.
276 */
277 for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
278 if (acpi_speed < supported_speeds[i])
279 break;
280 }
281 acpi_speed = supported_speeds[i - 1];
282
283 /*
284 * Find bus speed from the "clock-frequency" device property, ACPI
285 * or by using fast mode if neither is set.
286 */
287 if (acpi_speed && t->bus_freq_hz)
288 t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed);
289 else if (acpi_speed || t->bus_freq_hz)
290 t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed);
291 else
292 t->bus_freq_hz = 400000;
293
294 if (has_acpi_companion(&pdev->dev))
295 dw_i2c_acpi_configure(pdev);
296
297 /*
298 * Only standard mode at 100kHz, fast mode at 400kHz,
299 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
300 */
301 if (t->bus_freq_hz != 100000 && t->bus_freq_hz != 400000 &&
302 t->bus_freq_hz != 1000000 && t->bus_freq_hz != 3400000) {
303 dev_err(&pdev->dev,
304 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
305 t->bus_freq_hz);
306 ret = -EINVAL;
307 goto exit_reset;
308 }
309
310 ret = i2c_dw_probe_lock_support(dev);
311 if (ret)
312 goto exit_reset;
313
314 if (i2c_detect_slave_mode(&pdev->dev))
315 i2c_dw_configure_slave(dev);
316 else
317 i2c_dw_configure_master(dev);
318
319 dev->clk = devm_clk_get(&pdev->dev, NULL);
320 if (!i2c_dw_prepare_clk(dev, true)) {
321 u64 clk_khz;
322
323 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
324 clk_khz = dev->get_clk_rate_khz(dev);
325
326 if (!dev->sda_hold_time && t->sda_hold_ns)
327 dev->sda_hold_time =
328 div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000);
329 }
330
331 dw_i2c_set_fifo_size(dev, pdev->id);
332
333 adap = &dev->adapter;
334 adap->owner = THIS_MODULE;
335 adap->class = I2C_CLASS_DEPRECATED;
336 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
337 adap->dev.of_node = pdev->dev.of_node;
338
339 dev_pm_set_driver_flags(&pdev->dev,
340 DPM_FLAG_SMART_PREPARE |
341 DPM_FLAG_SMART_SUSPEND |
342 DPM_FLAG_LEAVE_SUSPENDED);
343
344 /* The code below assumes runtime PM to be disabled. */
345 WARN_ON(pm_runtime_enabled(&pdev->dev));
346
347 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
348 pm_runtime_use_autosuspend(&pdev->dev);
349 pm_runtime_set_active(&pdev->dev);
350
351 if (dev->pm_disabled)
352 pm_runtime_get_noresume(&pdev->dev);
353
354 pm_runtime_enable(&pdev->dev);
355
356 if (dev->mode == DW_IC_SLAVE)
357 ret = i2c_dw_probe_slave(dev);
358 else
359 ret = i2c_dw_probe(dev);
360
361 if (ret)
362 goto exit_probe;
363
364 return ret;
365
366 exit_probe:
367 dw_i2c_plat_pm_cleanup(dev);
368 exit_reset:
369 if (!IS_ERR_OR_NULL(dev->rst))
370 reset_control_assert(dev->rst);
371 return ret;
372 }
373
dw_i2c_plat_remove(struct platform_device * pdev)374 static int dw_i2c_plat_remove(struct platform_device *pdev)
375 {
376 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
377
378 pm_runtime_get_sync(&pdev->dev);
379
380 i2c_del_adapter(&dev->adapter);
381
382 dev->disable(dev);
383
384 pm_runtime_dont_use_autosuspend(&pdev->dev);
385 pm_runtime_put_sync(&pdev->dev);
386 dw_i2c_plat_pm_cleanup(dev);
387
388 if (!IS_ERR_OR_NULL(dev->rst))
389 reset_control_assert(dev->rst);
390
391 i2c_dw_remove_lock_support(dev);
392
393 return 0;
394 }
395
396 #ifdef CONFIG_OF
397 static const struct of_device_id dw_i2c_of_match[] = {
398 { .compatible = "snps,designware-i2c", },
399 {},
400 };
401 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
402 #endif
403
404 #ifdef CONFIG_PM_SLEEP
dw_i2c_plat_prepare(struct device * dev)405 static int dw_i2c_plat_prepare(struct device *dev)
406 {
407 /*
408 * If the ACPI companion device object is present for this device, it
409 * may be accessed during suspend and resume of other devices via I2C
410 * operation regions, so tell the PM core and middle layers to avoid
411 * skipping system suspend/resume callbacks for it in that case.
412 */
413 return !has_acpi_companion(dev);
414 }
415
dw_i2c_plat_complete(struct device * dev)416 static void dw_i2c_plat_complete(struct device *dev)
417 {
418 /*
419 * The device can only be in runtime suspend at this point if it has not
420 * been resumed throughout the ending system suspend/resume cycle, so if
421 * the platform firmware might mess up with it, request the runtime PM
422 * framework to resume it.
423 */
424 if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
425 pm_request_resume(dev);
426 }
427 #else
428 #define dw_i2c_plat_prepare NULL
429 #define dw_i2c_plat_complete NULL
430 #endif
431
432 #ifdef CONFIG_PM
dw_i2c_plat_suspend(struct device * dev)433 static int dw_i2c_plat_suspend(struct device *dev)
434 {
435 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
436
437 if (i_dev->pm_disabled)
438 return 0;
439
440 i_dev->disable(i_dev);
441 i2c_dw_prepare_clk(i_dev, false);
442
443 return 0;
444 }
445
dw_i2c_plat_resume(struct device * dev)446 static int dw_i2c_plat_resume(struct device *dev)
447 {
448 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
449
450 if (!i_dev->pm_disabled)
451 i2c_dw_prepare_clk(i_dev, true);
452
453 i_dev->init(i_dev);
454
455 return 0;
456 }
457
458 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
459 .prepare = dw_i2c_plat_prepare,
460 .complete = dw_i2c_plat_complete,
461 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
462 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
463 };
464
465 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
466 #else
467 #define DW_I2C_DEV_PMOPS NULL
468 #endif
469
470 /* Work with hotplug and coldplug */
471 MODULE_ALIAS("platform:i2c_designware");
472
473 static struct platform_driver dw_i2c_driver = {
474 .probe = dw_i2c_plat_probe,
475 .remove = dw_i2c_plat_remove,
476 .driver = {
477 .name = "i2c_designware",
478 .of_match_table = of_match_ptr(dw_i2c_of_match),
479 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
480 .pm = DW_I2C_DEV_PMOPS,
481 },
482 };
483
dw_i2c_init_driver(void)484 static int __init dw_i2c_init_driver(void)
485 {
486 return platform_driver_register(&dw_i2c_driver);
487 }
488 subsys_initcall(dw_i2c_init_driver);
489
dw_i2c_exit_driver(void)490 static void __exit dw_i2c_exit_driver(void)
491 {
492 platform_driver_unregister(&dw_i2c_driver);
493 }
494 module_exit(dw_i2c_exit_driver);
495
496 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
497 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
498 MODULE_LICENSE("GPL");
499