summaryrefslogtreecommitdiff
path: root/drivers/i2c/busses/i2c-at91-core.c
blob: e13af4874976ef1ae493844dee464d3e0c3b6fb6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
// SPDX-License-Identifier: GPL-2.0
/*
 *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
 *
 *  Copyright (C) 2011 Weinmann Medical GmbH
 *  Author: Nikolaus Voss <n.voss@weinmann.de>
 *
 *  Evolved from original work by:
 *  Copyright (C) 2004 Rick Bronson
 *  Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
 *
 *  Borrowed heavily from original work by:
 *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/pinctrl/consumer.h>

#include "i2c-at91.h"

unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
{
	return readl_relaxed(dev->base + reg);
}

void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
{
	writel_relaxed(val, dev->base + reg);
}

void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
{
	at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
}

void at91_twi_irq_save(struct at91_twi_dev *dev)
{
	dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
	at91_disable_twi_interrupts(dev);
}

void at91_twi_irq_restore(struct at91_twi_dev *dev)
{
	at91_twi_write(dev, AT91_TWI_IER, dev->imr);
}

void at91_init_twi_bus(struct at91_twi_dev *dev)
{
	at91_disable_twi_interrupts(dev);
	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
	if (dev->slave_detected)
		at91_init_twi_bus_slave(dev);
	else
		at91_init_twi_bus_master(dev);
}

static struct at91_twi_pdata at91rm9200_config = {
	.clk_max_div = 5,
	.clk_offset = 3,
	.has_unre_flag = true,
	.has_alt_cmd = false,
	.has_hold_field = false,
	.has_dig_filtr = false,
	.has_adv_dig_filtr = false,
	.has_ana_filtr = false,
};

static struct at91_twi_pdata at91sam9261_config = {
	.clk_max_div = 5,
	.clk_offset = 4,
	.has_unre_flag = false,
	.has_alt_cmd = false,
	.has_hold_field = false,
	.has_dig_filtr = false,
	.has_adv_dig_filtr = false,
	.has_ana_filtr = false,
};

static struct at91_twi_pdata at91sam9260_config = {
	.clk_max_div = 7,
	.clk_offset = 4,
	.has_unre_flag = false,
	.has_alt_cmd = false,
	.has_hold_field = false,
	.has_dig_filtr = false,
	.has_adv_dig_filtr = false,
	.has_ana_filtr = false,
};

static struct at91_twi_pdata at91sam9g20_config = {
	.clk_max_div = 7,
	.clk_offset = 4,
	.has_unre_flag = false,
	.has_alt_cmd = false,
	.has_hold_field = false,
	.has_dig_filtr = false,
	.has_adv_dig_filtr = false,
	.has_ana_filtr = false,
};

static struct at91_twi_pdata at91sam9g10_config = {
	.clk_max_div = 7,
	.clk_offset = 4,
	.has_unre_flag = false,
	.has_alt_cmd = false,
	.has_hold_field = false,
	.has_dig_filtr = false,
	.has_adv_dig_filtr = false,
	.has_ana_filtr = false,
};

static const struct platform_device_id at91_twi_devtypes[] = {
	{
		.name = "i2c-at91rm9200",
		.driver_data = (unsigned long) &at91rm9200_config,
	}, {
		.name = "i2c-at91sam9261",
		.driver_data = (unsigned long) &at91sam9261_config,
	}, {
		.name = "i2c-at91sam9260",
		.driver_data = (unsigned long) &at91sam9260_config,
	}, {
		.name = "i2c-at91sam9g20",
		.driver_data = (unsigned long) &at91sam9g20_config,
	}, {
		.name = "i2c-at91sam9g10",
		.driver_data = (unsigned long) &at91sam9g10_config,
	}, {
		/* sentinel */
	}
};

#if defined(CONFIG_OF)
static struct at91_twi_pdata at91sam9x5_config = {
	.clk_max_div = 7,
	.clk_offset = 4,
	.has_unre_flag = false,
	.has_alt_cmd = false,
	.has_hold_field = false,
	.has_dig_filtr = false,
	.has_adv_dig_filtr = false,
	.has_ana_filtr = false,
};

static struct at91_twi_pdata sama5d4_config = {
	.clk_max_div = 7,
	.clk_offset = 4,
	.has_unre_flag = false,
	.has_alt_cmd = false,
	.has_hold_field = true,
	.has_dig_filtr = true,
	.has_adv_dig_filtr = false,
	.has_ana_filtr = false,
};

static struct at91_twi_pdata sama5d2_config = {
	.clk_max_div = 7,
	.clk_offset = 3,
	.has_unre_flag = true,
	.has_alt_cmd = true,
	.has_hold_field = true,
	.has_dig_filtr = true,
	.has_adv_dig_filtr = true,
	.has_ana_filtr = true,
};

static struct at91_twi_pdata sam9x60_config = {
	.clk_max_div = 7,
	.clk_offset = 4,
	.has_unre_flag = true,
	.has_alt_cmd = true,
	.has_hold_field = true,
	.has_dig_filtr = true,
	.has_adv_dig_filtr = true,
	.has_ana_filtr = true,
};

static const struct of_device_id atmel_twi_dt_ids[] = {
	{
		.compatible = "atmel,at91rm9200-i2c",
		.data = &at91rm9200_config,
	}, {
		.compatible = "atmel,at91sam9260-i2c",
		.data = &at91sam9260_config,
	}, {
		.compatible = "atmel,at91sam9261-i2c",
		.data = &at91sam9261_config,
	}, {
		.compatible = "atmel,at91sam9g20-i2c",
		.data = &at91sam9g20_config,
	}, {
		.compatible = "atmel,at91sam9g10-i2c",
		.data = &at91sam9g10_config,
	}, {
		.compatible = "atmel,at91sam9x5-i2c",
		.data = &at91sam9x5_config,
	}, {
		.compatible = "atmel,sama5d4-i2c",
		.data = &sama5d4_config,
	}, {
		.compatible = "atmel,sama5d2-i2c",
		.data = &sama5d2_config,
	}, {
		.compatible = "microchip,sam9x60-i2c",
		.data = &sam9x60_config,
	}, {
		/* sentinel */
	}
};
MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
#endif

static struct at91_twi_pdata *at91_twi_get_driver_data(
					struct platform_device *pdev)
{
	if (pdev->dev.of_node) {
		const struct of_device_id *match;
		match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
		if (!match)
			return NULL;
		return (struct at91_twi_pdata *)match->data;
	}
	return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
}

static int at91_twi_probe(struct platform_device *pdev)
{
	struct at91_twi_dev *dev;
	struct resource *mem;
	int rc;
	u32 phy_addr;

	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;

	dev->dev = &pdev->dev;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem)
		return -ENODEV;
	phy_addr = mem->start;

	dev->pdata = at91_twi_get_driver_data(pdev);
	if (!dev->pdata)
		return -ENODEV;

	dev->base = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(dev->base))
		return PTR_ERR(dev->base);

	dev->irq = platform_get_irq(pdev, 0);
	if (dev->irq < 0)
		return dev->irq;

	platform_set_drvdata(pdev, dev);

	dev->clk = devm_clk_get(dev->dev, NULL);
	if (IS_ERR(dev->clk)) {
		dev_err(dev->dev, "no clock defined\n");
		return -ENODEV;
	}
	clk_prepare_enable(dev->clk);

	snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
	i2c_set_adapdata(&dev->adapter, dev);
	dev->adapter.owner = THIS_MODULE;
	dev->adapter.class = I2C_CLASS_DEPRECATED;
	dev->adapter.dev.parent = dev->dev;
	dev->adapter.nr = pdev->id;
	dev->adapter.timeout = AT91_I2C_TIMEOUT;
	dev->adapter.dev.of_node = pdev->dev.of_node;

	dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);

	if (dev->slave_detected)
		rc = at91_twi_probe_slave(pdev, phy_addr, dev);
	else
		rc = at91_twi_probe_master(pdev, phy_addr, dev);
	if (rc)
		return rc;

	at91_init_twi_bus(dev);

	pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
	pm_runtime_use_autosuspend(dev->dev);
	pm_runtime_set_active(dev->dev);
	pm_runtime_enable(dev->dev);

	rc = i2c_add_numbered_adapter(&dev->adapter);
	if (rc) {
		clk_disable_unprepare(dev->clk);

		pm_runtime_disable(dev->dev);
		pm_runtime_set_suspended(dev->dev);

		return rc;
	}

	dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
		 at91_twi_read(dev, AT91_TWI_VER));
	return 0;
}

static int at91_twi_remove(struct platform_device *pdev)
{
	struct at91_twi_dev *dev = platform_get_drvdata(pdev);

	i2c_del_adapter(&dev->adapter);
	clk_disable_unprepare(dev->clk);

	pm_runtime_disable(dev->dev);
	pm_runtime_set_suspended(dev->dev);

	return 0;
}

#ifdef CONFIG_PM

static int at91_twi_runtime_suspend(struct device *dev)
{
	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);

	clk_disable_unprepare(twi_dev->clk);

	pinctrl_pm_select_sleep_state(dev);

	return 0;
}

static int at91_twi_runtime_resume(struct device *dev)
{
	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);

	pinctrl_pm_select_default_state(dev);

	return clk_prepare_enable(twi_dev->clk);
}

static int at91_twi_suspend_noirq(struct device *dev)
{
	if (!pm_runtime_status_suspended(dev))
		at91_twi_runtime_suspend(dev);

	return 0;
}

static int at91_twi_resume_noirq(struct device *dev)
{
	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
	int ret;

	if (!pm_runtime_status_suspended(dev)) {
		ret = at91_twi_runtime_resume(dev);
		if (ret)
			return ret;
	}

	pm_runtime_mark_last_busy(dev);
	pm_request_autosuspend(dev);

	at91_init_twi_bus(twi_dev);

	return 0;
}

static const struct dev_pm_ops at91_twi_pm = {
	.suspend_noirq	= at91_twi_suspend_noirq,
	.resume_noirq	= at91_twi_resume_noirq,
	.runtime_suspend	= at91_twi_runtime_suspend,
	.runtime_resume		= at91_twi_runtime_resume,
};

#define at91_twi_pm_ops (&at91_twi_pm)
#else
#define at91_twi_pm_ops NULL
#endif

static struct platform_driver at91_twi_driver = {
	.probe		= at91_twi_probe,
	.remove		= at91_twi_remove,
	.id_table	= at91_twi_devtypes,
	.driver		= {
		.name	= "at91_i2c",
		.of_match_table = of_match_ptr(atmel_twi_dt_ids),
		.pm	= at91_twi_pm_ops,
	},
};

static int __init at91_twi_init(void)
{
	return platform_driver_register(&at91_twi_driver);
}

static void __exit at91_twi_exit(void)
{
	platform_driver_unregister(&at91_twi_driver);
}

subsys_initcall(at91_twi_init);
module_exit(at91_twi_exit);

MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:at91_i2c");