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_data/i2c-designware.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/property.h>
30 #include <linux/regmap.h>
31 #include <linux/reset.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/suspend.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)/1000;
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 	{ "AMDI0510", 0 },
54 	{ "APMC0D0F", 0 },
55 	{ "HISI02A1", 0 },
56 	{ "HISI02A2", 0 },
57 	{ "HISI02A3", 0 },
58 	{ "HYGO0010", ACCESS_INTR_MASK },
59 	{ }
60 };
61 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
62 #endif
63 
64 #ifdef CONFIG_OF
65 #define BT1_I2C_CTL			0x100
66 #define BT1_I2C_CTL_ADDR_MASK		GENMASK(7, 0)
67 #define BT1_I2C_CTL_WR			BIT(8)
68 #define BT1_I2C_CTL_GO			BIT(31)
69 #define BT1_I2C_DI			0x104
70 #define BT1_I2C_DO			0x108
71 
72 static int bt1_i2c_read(void *context, unsigned int reg, unsigned int *val)
73 {
74 	struct dw_i2c_dev *dev = context;
75 	int ret;
76 
77 	/*
78 	 * Note these methods shouldn't ever fail because the system controller
79 	 * registers are memory mapped. We check the return value just in case.
80 	 */
81 	ret = regmap_write(dev->sysmap, BT1_I2C_CTL,
82 			   BT1_I2C_CTL_GO | (reg & BT1_I2C_CTL_ADDR_MASK));
83 	if (ret)
84 		return ret;
85 
86 	return regmap_read(dev->sysmap, BT1_I2C_DO, val);
87 }
88 
89 static int bt1_i2c_write(void *context, unsigned int reg, unsigned int val)
90 {
91 	struct dw_i2c_dev *dev = context;
92 	int ret;
93 
94 	ret = regmap_write(dev->sysmap, BT1_I2C_DI, val);
95 	if (ret)
96 		return ret;
97 
98 	return regmap_write(dev->sysmap, BT1_I2C_CTL,
99 		BT1_I2C_CTL_GO | BT1_I2C_CTL_WR | (reg & BT1_I2C_CTL_ADDR_MASK));
100 }
101 
102 static struct regmap_config bt1_i2c_cfg = {
103 	.reg_bits = 32,
104 	.val_bits = 32,
105 	.reg_stride = 4,
106 	.fast_io = true,
107 	.reg_read = bt1_i2c_read,
108 	.reg_write = bt1_i2c_write,
109 	.max_register = DW_IC_COMP_TYPE,
110 };
111 
112 static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
113 {
114 	dev->sysmap = syscon_node_to_regmap(dev->dev->of_node->parent);
115 	if (IS_ERR(dev->sysmap))
116 		return PTR_ERR(dev->sysmap);
117 
118 	dev->map = devm_regmap_init(dev->dev, NULL, dev, &bt1_i2c_cfg);
119 	return PTR_ERR_OR_ZERO(dev->map);
120 }
121 
122 #define MSCC_ICPU_CFG_TWI_DELAY		0x0
123 #define MSCC_ICPU_CFG_TWI_DELAY_ENABLE	BIT(0)
124 #define MSCC_ICPU_CFG_TWI_SPIKE_FILTER	0x4
125 
126 static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
127 {
128 	writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE,
129 	       dev->ext + MSCC_ICPU_CFG_TWI_DELAY);
130 
131 	return 0;
132 }
133 
134 static int dw_i2c_of_configure(struct platform_device *pdev)
135 {
136 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
137 
138 	switch (dev->flags & MODEL_MASK) {
139 	case MODEL_MSCC_OCELOT:
140 		dev->ext = devm_platform_ioremap_resource(pdev, 1);
141 		if (!IS_ERR(dev->ext))
142 			dev->set_sda_hold_time = mscc_twi_set_sda_hold_time;
143 		break;
144 	default:
145 		break;
146 	}
147 
148 	return 0;
149 }
150 
151 static const struct of_device_id dw_i2c_of_match[] = {
152 	{ .compatible = "snps,designware-i2c", },
153 	{ .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
154 	{ .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 },
155 	{},
156 };
157 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
158 #else
159 static int bt1_i2c_request_regs(struct dw_i2c_dev *dev)
160 {
161 	return -ENODEV;
162 }
163 
164 static inline int dw_i2c_of_configure(struct platform_device *pdev)
165 {
166 	return -ENODEV;
167 }
168 #endif
169 
170 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
171 {
172 	pm_runtime_disable(dev->dev);
173 
174 	if (dev->shared_with_punit)
175 		pm_runtime_put_noidle(dev->dev);
176 }
177 
178 static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
179 {
180 	struct platform_device *pdev = to_platform_device(dev->dev);
181 	int ret;
182 
183 	switch (dev->flags & MODEL_MASK) {
184 	case MODEL_BAIKAL_BT1:
185 		ret = bt1_i2c_request_regs(dev);
186 		break;
187 	default:
188 		dev->base = devm_platform_ioremap_resource(pdev, 0);
189 		ret = PTR_ERR_OR_ZERO(dev->base);
190 		break;
191 	}
192 
193 	return ret;
194 }
195 
196 static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = {
197 	{
198 		.ident = "Qtechnology QT5222",
199 		.matches = {
200 			DMI_MATCH(DMI_SYS_VENDOR, "Qtechnology"),
201 			DMI_MATCH(DMI_PRODUCT_NAME, "QT5222"),
202 		},
203 	},
204 	{ } /* terminate list */
205 };
206 
207 static int dw_i2c_plat_probe(struct platform_device *pdev)
208 {
209 	struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
210 	struct i2c_adapter *adap;
211 	struct dw_i2c_dev *dev;
212 	struct i2c_timings *t;
213 	int irq, ret;
214 
215 	irq = platform_get_irq(pdev, 0);
216 	if (irq < 0)
217 		return irq;
218 
219 	dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
220 	if (!dev)
221 		return -ENOMEM;
222 
223 	dev->flags = (uintptr_t)device_get_match_data(&pdev->dev);
224 	dev->dev = &pdev->dev;
225 	dev->irq = irq;
226 	platform_set_drvdata(pdev, dev);
227 
228 	ret = dw_i2c_plat_request_regs(dev);
229 	if (ret)
230 		return ret;
231 
232 	dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
233 	if (IS_ERR(dev->rst))
234 		return PTR_ERR(dev->rst);
235 
236 	reset_control_deassert(dev->rst);
237 
238 	t = &dev->timings;
239 	if (pdata)
240 		t->bus_freq_hz = pdata->i2c_scl_freq;
241 	else
242 		i2c_parse_fw_timings(&pdev->dev, t, false);
243 
244 	i2c_dw_adjust_bus_speed(dev);
245 
246 	if (pdev->dev.of_node)
247 		dw_i2c_of_configure(pdev);
248 
249 	if (has_acpi_companion(&pdev->dev))
250 		i2c_dw_acpi_configure(&pdev->dev);
251 
252 	ret = i2c_dw_validate_speed(dev);
253 	if (ret)
254 		goto exit_reset;
255 
256 	ret = i2c_dw_probe_lock_support(dev);
257 	if (ret)
258 		goto exit_reset;
259 
260 	i2c_dw_configure(dev);
261 
262 	/* Optional interface clock */
263 	dev->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
264 	if (IS_ERR(dev->pclk)) {
265 		ret = PTR_ERR(dev->pclk);
266 		goto exit_reset;
267 	}
268 
269 	dev->clk = devm_clk_get(&pdev->dev, NULL);
270 	if (!i2c_dw_prepare_clk(dev, true)) {
271 		u64 clk_khz;
272 
273 		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
274 		clk_khz = dev->get_clk_rate_khz(dev);
275 
276 		if (!dev->sda_hold_time && t->sda_hold_ns)
277 			dev->sda_hold_time =
278 				div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000);
279 	}
280 
281 	adap = &dev->adapter;
282 	adap->owner = THIS_MODULE;
283 	adap->class = dmi_check_system(dw_i2c_hwmon_class_dmi) ?
284 					I2C_CLASS_HWMON : I2C_CLASS_DEPRECATED;
285 	ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
286 	adap->dev.of_node = pdev->dev.of_node;
287 	adap->nr = -1;
288 
289 	if (dev->flags & ACCESS_NO_IRQ_SUSPEND) {
290 		dev_pm_set_driver_flags(&pdev->dev,
291 					DPM_FLAG_SMART_PREPARE |
292 					DPM_FLAG_MAY_SKIP_RESUME);
293 	} else {
294 		dev_pm_set_driver_flags(&pdev->dev,
295 					DPM_FLAG_SMART_PREPARE |
296 					DPM_FLAG_SMART_SUSPEND |
297 					DPM_FLAG_MAY_SKIP_RESUME);
298 	}
299 
300 	/* The code below assumes runtime PM to be disabled. */
301 	WARN_ON(pm_runtime_enabled(&pdev->dev));
302 
303 	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
304 	pm_runtime_use_autosuspend(&pdev->dev);
305 	pm_runtime_set_active(&pdev->dev);
306 
307 	if (dev->shared_with_punit)
308 		pm_runtime_get_noresume(&pdev->dev);
309 
310 	pm_runtime_enable(&pdev->dev);
311 
312 	ret = i2c_dw_probe(dev);
313 	if (ret)
314 		goto exit_probe;
315 
316 	return ret;
317 
318 exit_probe:
319 	dw_i2c_plat_pm_cleanup(dev);
320 exit_reset:
321 	reset_control_assert(dev->rst);
322 	return ret;
323 }
324 
325 static int dw_i2c_plat_remove(struct platform_device *pdev)
326 {
327 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
328 
329 	pm_runtime_get_sync(&pdev->dev);
330 
331 	i2c_del_adapter(&dev->adapter);
332 
333 	dev->disable(dev);
334 
335 	pm_runtime_dont_use_autosuspend(&pdev->dev);
336 	pm_runtime_put_sync(&pdev->dev);
337 	dw_i2c_plat_pm_cleanup(dev);
338 
339 	reset_control_assert(dev->rst);
340 
341 	return 0;
342 }
343 
344 #ifdef CONFIG_PM_SLEEP
345 static int dw_i2c_plat_prepare(struct device *dev)
346 {
347 	/*
348 	 * If the ACPI companion device object is present for this device, it
349 	 * may be accessed during suspend and resume of other devices via I2C
350 	 * operation regions, so tell the PM core and middle layers to avoid
351 	 * skipping system suspend/resume callbacks for it in that case.
352 	 */
353 	return !has_acpi_companion(dev);
354 }
355 
356 static void dw_i2c_plat_complete(struct device *dev)
357 {
358 	/*
359 	 * The device can only be in runtime suspend at this point if it has not
360 	 * been resumed throughout the ending system suspend/resume cycle, so if
361 	 * the platform firmware might mess up with it, request the runtime PM
362 	 * framework to resume it.
363 	 */
364 	if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
365 		pm_request_resume(dev);
366 }
367 #else
368 #define dw_i2c_plat_prepare	NULL
369 #define dw_i2c_plat_complete	NULL
370 #endif
371 
372 #ifdef CONFIG_PM
373 static int dw_i2c_plat_suspend(struct device *dev)
374 {
375 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
376 
377 	i_dev->suspended = true;
378 
379 	if (i_dev->shared_with_punit)
380 		return 0;
381 
382 	i_dev->disable(i_dev);
383 	i2c_dw_prepare_clk(i_dev, false);
384 
385 	return 0;
386 }
387 
388 static int dw_i2c_plat_resume(struct device *dev)
389 {
390 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
391 
392 	if (!i_dev->shared_with_punit)
393 		i2c_dw_prepare_clk(i_dev, true);
394 
395 	i_dev->init(i_dev);
396 	i_dev->suspended = false;
397 
398 	return 0;
399 }
400 
401 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
402 	.prepare = dw_i2c_plat_prepare,
403 	.complete = dw_i2c_plat_complete,
404 	SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
405 	SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
406 };
407 
408 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
409 #else
410 #define DW_I2C_DEV_PMOPS NULL
411 #endif
412 
413 /* Work with hotplug and coldplug */
414 MODULE_ALIAS("platform:i2c_designware");
415 
416 static struct platform_driver dw_i2c_driver = {
417 	.probe = dw_i2c_plat_probe,
418 	.remove = dw_i2c_plat_remove,
419 	.driver		= {
420 		.name	= "i2c_designware",
421 		.of_match_table = of_match_ptr(dw_i2c_of_match),
422 		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
423 		.pm	= DW_I2C_DEV_PMOPS,
424 	},
425 };
426 
427 static int __init dw_i2c_init_driver(void)
428 {
429 	return platform_driver_register(&dw_i2c_driver);
430 }
431 subsys_initcall(dw_i2c_init_driver);
432 
433 static void __exit dw_i2c_exit_driver(void)
434 {
435 	platform_driver_unregister(&dw_i2c_driver);
436 }
437 module_exit(dw_i2c_exit_driver);
438 
439 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
440 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
441 MODULE_LICENSE("GPL");
442