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/mfd/syscon.h>
23 #include <linux/module.h>
24 #include <linux/of.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/regmap.h>
30 #include <linux/reset.h>
31 #include <linux/sched.h>
32 #include <linux/slab.h>
33 #include <linux/suspend.h>
34 #include <linux/units.h>
35 
36 #include "i2c-designware-core.h"
37 
38 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
39 {
40 	return clk_get_rate(dev->clk) / KILO;
41 }
42 
43 #ifdef CONFIG_ACPI
44 static const struct acpi_device_id dw_i2c_acpi_match[] = {
45 	{ "INT33C2", 0 },
46 	{ "INT33C3", 0 },
47 	{ "INT3432", 0 },
48 	{ "INT3433", 0 },
49 	{ "80860F41", ACCESS_NO_IRQ_SUSPEND },
50 	{ "808622C1", ACCESS_NO_IRQ_SUSPEND },
51 	{ "AMD0010", ACCESS_INTR_MASK },
52 	{ "AMDI0010", ACCESS_INTR_MASK },
53 	{ "AMDI0019", ACCESS_INTR_MASK | ARBITRATION_SEMAPHORE },
54 	{ "AMDI0510", 0 },
55 	{ "APMC0D0F", 0 },
56 	{ "HISI02A1", 0 },
57 	{ "HISI02A2", 0 },
58 	{ "HISI02A3", 0 },
59 	{ "HYGO0010", ACCESS_INTR_MASK },
60 	{ }
61 };
62 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
63 #endif
64 
65 #ifdef CONFIG_OF
66 #define BT1_I2C_CTL			0x100
67 #define BT1_I2C_CTL_ADDR_MASK		GENMASK(7, 0)
68 #define BT1_I2C_CTL_WR			BIT(8)
69 #define BT1_I2C_CTL_GO			BIT(31)
70 #define BT1_I2C_DI			0x104
71 #define BT1_I2C_DO			0x108
72 
73 static int bt1_i2c_read(void *context, unsigned int reg, unsigned int *val)
74 {
75 	struct dw_i2c_dev *dev = context;
76 	int ret;
77 
78 	/*
79 	 * Note these methods shouldn't ever fail because the system controller
80 	 * registers are memory mapped. We check the return value just in case.
81 	 */
82 	ret = regmap_write(dev->sysmap, BT1_I2C_CTL,
83 			   BT1_I2C_CTL_GO | (reg & BT1_I2C_CTL_ADDR_MASK));
84 	if (ret)
85 		return ret;
86 
87 	return regmap_read(dev->sysmap, BT1_I2C_DO, val);
88 }
89 
90 static int bt1_i2c_write(void *context, unsigned int reg, unsigned int val)
91 {
92 	struct dw_i2c_dev *dev = context;
93 	int ret;
94 
95 	ret = regmap_write(dev->sysmap, BT1_I2C_DI, val);
96 	if (ret)
97 		return ret;
98 
99 	return regmap_write(dev->sysmap, BT1_I2C_CTL,
100 		BT1_I2C_CTL_GO | BT1_I2C_CTL_WR | (reg & BT1_I2C_CTL_ADDR_MASK));
101 }
102 
103 static struct regmap_config bt1_i2c_cfg = {
104 	.reg_bits = 32,
105 	.val_bits = 32,
106 	.reg_stride = 4,
107 	.fast_io = true,
108 	.reg_read = bt1_i2c_read,
109 	.reg_write = bt1_i2c_write,
110 	.max_register = DW_IC_COMP_TYPE,
111 };
112 
113 static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
114 {
115 	dev->sysmap = syscon_node_to_regmap(dev->dev->of_node->parent);
116 	if (IS_ERR(dev->sysmap))
117 		return PTR_ERR(dev->sysmap);
118 
119 	dev->map = devm_regmap_init(dev->dev, NULL, dev, &bt1_i2c_cfg);
120 	return PTR_ERR_OR_ZERO(dev->map);
121 }
122 
123 #define MSCC_ICPU_CFG_TWI_DELAY		0x0
124 #define MSCC_ICPU_CFG_TWI_DELAY_ENABLE	BIT(0)
125 #define MSCC_ICPU_CFG_TWI_SPIKE_FILTER	0x4
126 
127 static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
128 {
129 	writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE,
130 	       dev->ext + MSCC_ICPU_CFG_TWI_DELAY);
131 
132 	return 0;
133 }
134 
135 static int dw_i2c_of_configure(struct platform_device *pdev)
136 {
137 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
138 
139 	switch (dev->flags & MODEL_MASK) {
140 	case MODEL_MSCC_OCELOT:
141 		dev->ext = devm_platform_ioremap_resource(pdev, 1);
142 		if (!IS_ERR(dev->ext))
143 			dev->set_sda_hold_time = mscc_twi_set_sda_hold_time;
144 		break;
145 	default:
146 		break;
147 	}
148 
149 	return 0;
150 }
151 
152 static const struct of_device_id dw_i2c_of_match[] = {
153 	{ .compatible = "snps,designware-i2c", },
154 	{ .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
155 	{ .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 },
156 	{},
157 };
158 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
159 #else
160 static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
161 {
162 	return -ENODEV;
163 }
164 
165 static inline int dw_i2c_of_configure(struct platform_device *pdev)
166 {
167 	return -ENODEV;
168 }
169 #endif
170 
171 static int txgbe_i2c_request_regs(struct dw_i2c_dev *dev)
172 {
173 	dev->map = dev_get_regmap(dev->dev->parent, NULL);
174 	if (!dev->map)
175 		return -ENODEV;
176 
177 	return 0;
178 }
179 
180 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
181 {
182 	pm_runtime_disable(dev->dev);
183 
184 	if (dev->shared_with_punit)
185 		pm_runtime_put_noidle(dev->dev);
186 }
187 
188 static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
189 {
190 	struct platform_device *pdev = to_platform_device(dev->dev);
191 	int ret;
192 
193 	switch (dev->flags & MODEL_MASK) {
194 	case MODEL_BAIKAL_BT1:
195 		ret = bt1_i2c_request_regs(dev);
196 		break;
197 	case MODEL_WANGXUN_SP:
198 		ret = txgbe_i2c_request_regs(dev);
199 		break;
200 	default:
201 		dev->base = devm_platform_ioremap_resource(pdev, 0);
202 		ret = PTR_ERR_OR_ZERO(dev->base);
203 		break;
204 	}
205 
206 	return ret;
207 }
208 
209 static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = {
210 	{
211 		.ident = "Qtechnology QT5222",
212 		.matches = {
213 			DMI_MATCH(DMI_SYS_VENDOR, "Qtechnology"),
214 			DMI_MATCH(DMI_PRODUCT_NAME, "QT5222"),
215 		},
216 	},
217 	{ } /* terminate list */
218 };
219 
220 static const struct i2c_dw_semaphore_callbacks i2c_dw_semaphore_cb_table[] = {
221 #ifdef CONFIG_I2C_DESIGNWARE_BAYTRAIL
222 	{
223 		.probe = i2c_dw_baytrail_probe_lock_support,
224 	},
225 #endif
226 #ifdef CONFIG_I2C_DESIGNWARE_AMDPSP
227 	{
228 		.probe = i2c_dw_amdpsp_probe_lock_support,
229 	},
230 #endif
231 	{}
232 };
233 
234 static int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev)
235 {
236 	const struct i2c_dw_semaphore_callbacks *ptr;
237 	int i = 0;
238 	int ret;
239 
240 	ptr = i2c_dw_semaphore_cb_table;
241 
242 	dev->semaphore_idx = -1;
243 
244 	while (ptr->probe) {
245 		ret = ptr->probe(dev);
246 		if (ret) {
247 			/*
248 			 * If there is no semaphore device attached to this
249 			 * controller, we shouldn't abort general i2c_controller
250 			 * probe.
251 			 */
252 			if (ret != -ENODEV)
253 				return ret;
254 
255 			i++;
256 			ptr++;
257 			continue;
258 		}
259 
260 		dev->semaphore_idx = i;
261 		break;
262 	}
263 
264 	return 0;
265 }
266 
267 static void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev)
268 {
269 	if (dev->semaphore_idx < 0)
270 		return;
271 
272 	if (i2c_dw_semaphore_cb_table[dev->semaphore_idx].remove)
273 		i2c_dw_semaphore_cb_table[dev->semaphore_idx].remove(dev);
274 }
275 
276 static int dw_i2c_plat_probe(struct platform_device *pdev)
277 {
278 	struct i2c_adapter *adap;
279 	struct dw_i2c_dev *dev;
280 	struct i2c_timings *t;
281 	int irq, ret;
282 
283 	irq = platform_get_irq(pdev, 0);
284 	if (irq < 0)
285 		return irq;
286 
287 	dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
288 	if (!dev)
289 		return -ENOMEM;
290 
291 	dev->flags = (uintptr_t)device_get_match_data(&pdev->dev);
292 	if (device_property_present(&pdev->dev, "wx,i2c-snps-model"))
293 		dev->flags = MODEL_WANGXUN_SP;
294 
295 	dev->dev = &pdev->dev;
296 	dev->irq = irq;
297 	platform_set_drvdata(pdev, dev);
298 
299 	ret = dw_i2c_plat_request_regs(dev);
300 	if (ret)
301 		return ret;
302 
303 	dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
304 	if (IS_ERR(dev->rst))
305 		return PTR_ERR(dev->rst);
306 
307 	reset_control_deassert(dev->rst);
308 
309 	t = &dev->timings;
310 	i2c_parse_fw_timings(&pdev->dev, t, false);
311 
312 	i2c_dw_adjust_bus_speed(dev);
313 
314 	if (pdev->dev.of_node)
315 		dw_i2c_of_configure(pdev);
316 
317 	if (has_acpi_companion(&pdev->dev))
318 		i2c_dw_acpi_configure(&pdev->dev);
319 
320 	ret = i2c_dw_validate_speed(dev);
321 	if (ret)
322 		goto exit_reset;
323 
324 	ret = i2c_dw_probe_lock_support(dev);
325 	if (ret)
326 		goto exit_reset;
327 
328 	i2c_dw_configure(dev);
329 
330 	/* Optional interface clock */
331 	dev->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
332 	if (IS_ERR(dev->pclk)) {
333 		ret = PTR_ERR(dev->pclk);
334 		goto exit_reset;
335 	}
336 
337 	dev->clk = devm_clk_get_optional(&pdev->dev, NULL);
338 	if (IS_ERR(dev->clk)) {
339 		ret = PTR_ERR(dev->clk);
340 		goto exit_reset;
341 	}
342 
343 	ret = i2c_dw_prepare_clk(dev, true);
344 	if (ret)
345 		goto exit_reset;
346 
347 	if (dev->clk) {
348 		u64 clk_khz;
349 
350 		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
351 		clk_khz = dev->get_clk_rate_khz(dev);
352 
353 		if (!dev->sda_hold_time && t->sda_hold_ns)
354 			dev->sda_hold_time =
355 				DIV_S64_ROUND_CLOSEST(clk_khz * t->sda_hold_ns, MICRO);
356 	}
357 
358 	adap = &dev->adapter;
359 	adap->owner = THIS_MODULE;
360 	adap->class = dmi_check_system(dw_i2c_hwmon_class_dmi) ?
361 					I2C_CLASS_HWMON : I2C_CLASS_DEPRECATED;
362 	ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
363 	adap->dev.of_node = pdev->dev.of_node;
364 	adap->nr = -1;
365 
366 	if (dev->flags & ACCESS_NO_IRQ_SUSPEND) {
367 		dev_pm_set_driver_flags(&pdev->dev,
368 					DPM_FLAG_SMART_PREPARE);
369 	} else {
370 		dev_pm_set_driver_flags(&pdev->dev,
371 					DPM_FLAG_SMART_PREPARE |
372 					DPM_FLAG_SMART_SUSPEND);
373 	}
374 
375 	device_enable_async_suspend(&pdev->dev);
376 
377 	/* The code below assumes runtime PM to be disabled. */
378 	WARN_ON(pm_runtime_enabled(&pdev->dev));
379 
380 	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
381 	pm_runtime_use_autosuspend(&pdev->dev);
382 	pm_runtime_set_active(&pdev->dev);
383 
384 	if (dev->shared_with_punit)
385 		pm_runtime_get_noresume(&pdev->dev);
386 
387 	pm_runtime_enable(&pdev->dev);
388 
389 	ret = i2c_dw_probe(dev);
390 	if (ret)
391 		goto exit_probe;
392 
393 	return ret;
394 
395 exit_probe:
396 	dw_i2c_plat_pm_cleanup(dev);
397 exit_reset:
398 	reset_control_assert(dev->rst);
399 	return ret;
400 }
401 
402 static void dw_i2c_plat_remove(struct platform_device *pdev)
403 {
404 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
405 
406 	pm_runtime_get_sync(&pdev->dev);
407 
408 	i2c_del_adapter(&dev->adapter);
409 
410 	dev->disable(dev);
411 
412 	pm_runtime_dont_use_autosuspend(&pdev->dev);
413 	pm_runtime_put_sync(&pdev->dev);
414 	dw_i2c_plat_pm_cleanup(dev);
415 
416 	i2c_dw_remove_lock_support(dev);
417 
418 	reset_control_assert(dev->rst);
419 }
420 
421 static int dw_i2c_plat_prepare(struct device *dev)
422 {
423 	/*
424 	 * If the ACPI companion device object is present for this device, it
425 	 * may be accessed during suspend and resume of other devices via I2C
426 	 * operation regions, so tell the PM core and middle layers to avoid
427 	 * skipping system suspend/resume callbacks for it in that case.
428 	 */
429 	return !has_acpi_companion(dev);
430 }
431 
432 static int dw_i2c_plat_runtime_suspend(struct device *dev)
433 {
434 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
435 
436 	if (i_dev->shared_with_punit)
437 		return 0;
438 
439 	i_dev->disable(i_dev);
440 	i2c_dw_prepare_clk(i_dev, false);
441 
442 	return 0;
443 }
444 
445 static int dw_i2c_plat_suspend(struct device *dev)
446 {
447 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
448 
449 	i2c_mark_adapter_suspended(&i_dev->adapter);
450 
451 	return dw_i2c_plat_runtime_suspend(dev);
452 }
453 
454 static int dw_i2c_plat_runtime_resume(struct device *dev)
455 {
456 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
457 
458 	if (!i_dev->shared_with_punit)
459 		i2c_dw_prepare_clk(i_dev, true);
460 
461 	i_dev->init(i_dev);
462 
463 	return 0;
464 }
465 
466 static int dw_i2c_plat_resume(struct device *dev)
467 {
468 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
469 
470 	dw_i2c_plat_runtime_resume(dev);
471 	i2c_mark_adapter_resumed(&i_dev->adapter);
472 
473 	return 0;
474 }
475 
476 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
477 	.prepare = pm_sleep_ptr(dw_i2c_plat_prepare),
478 	LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
479 	RUNTIME_PM_OPS(dw_i2c_plat_runtime_suspend, dw_i2c_plat_runtime_resume, NULL)
480 };
481 
482 /* Work with hotplug and coldplug */
483 MODULE_ALIAS("platform:i2c_designware");
484 
485 static struct platform_driver dw_i2c_driver = {
486 	.probe = dw_i2c_plat_probe,
487 	.remove_new = dw_i2c_plat_remove,
488 	.driver		= {
489 		.name	= "i2c_designware",
490 		.of_match_table = of_match_ptr(dw_i2c_of_match),
491 		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
492 		.pm	= pm_ptr(&dw_i2c_dev_pm_ops),
493 	},
494 };
495 
496 static int __init dw_i2c_init_driver(void)
497 {
498 	return platform_driver_register(&dw_i2c_driver);
499 }
500 subsys_initcall(dw_i2c_init_driver);
501 
502 static void __exit dw_i2c_exit_driver(void)
503 {
504 	platform_driver_unregister(&dw_i2c_driver);
505 }
506 module_exit(dw_i2c_exit_driver);
507 
508 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
509 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
510 MODULE_LICENSE("GPL");
511