1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
4 *
5 *  Copyright (C) 2011 Weinmann Medical GmbH
6 *  Author: Nikolaus Voss <n.voss@weinmann.de>
7 *
8 *  Evolved from original work by:
9 *  Copyright (C) 2004 Rick Bronson
10 *  Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
11 *
12 *  Borrowed heavily from original work by:
13 *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
14 */
15
16#include <linux/clk.h>
17#include <linux/err.h>
18#include <linux/i2c.h>
19#include <linux/io.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/platform_device.h>
23#include <linux/pm_runtime.h>
24#include <linux/pinctrl/consumer.h>
25
26#include "i2c-at91.h"
27
28unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
29{
30	return readl_relaxed(dev->base + reg);
31}
32
33void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
34{
35	writel_relaxed(val, dev->base + reg);
36}
37
38void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
39{
40	at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
41}
42
43void at91_twi_irq_save(struct at91_twi_dev *dev)
44{
45	dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
46	at91_disable_twi_interrupts(dev);
47}
48
49void at91_twi_irq_restore(struct at91_twi_dev *dev)
50{
51	at91_twi_write(dev, AT91_TWI_IER, dev->imr);
52}
53
54void at91_init_twi_bus(struct at91_twi_dev *dev)
55{
56	at91_disable_twi_interrupts(dev);
57	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
58	if (dev->slave_detected)
59		at91_init_twi_bus_slave(dev);
60	else
61		at91_init_twi_bus_master(dev);
62}
63
64static struct at91_twi_pdata at91rm9200_config = {
65	.clk_max_div = 5,
66	.clk_offset = 3,
67	.has_unre_flag = true,
68};
69
70static struct at91_twi_pdata at91sam9261_config = {
71	.clk_max_div = 5,
72	.clk_offset = 4,
73};
74
75static struct at91_twi_pdata at91sam9260_config = {
76	.clk_max_div = 7,
77	.clk_offset = 4,
78};
79
80static struct at91_twi_pdata at91sam9g20_config = {
81	.clk_max_div = 7,
82	.clk_offset = 4,
83};
84
85static struct at91_twi_pdata at91sam9g10_config = {
86	.clk_max_div = 7,
87	.clk_offset = 4,
88};
89
90static const struct platform_device_id at91_twi_devtypes[] = {
91	{
92		.name = "i2c-at91rm9200",
93		.driver_data = (unsigned long) &at91rm9200_config,
94	}, {
95		.name = "i2c-at91sam9261",
96		.driver_data = (unsigned long) &at91sam9261_config,
97	}, {
98		.name = "i2c-at91sam9260",
99		.driver_data = (unsigned long) &at91sam9260_config,
100	}, {
101		.name = "i2c-at91sam9g20",
102		.driver_data = (unsigned long) &at91sam9g20_config,
103	}, {
104		.name = "i2c-at91sam9g10",
105		.driver_data = (unsigned long) &at91sam9g10_config,
106	}, {
107		/* sentinel */
108	}
109};
110
111#if defined(CONFIG_OF)
112static struct at91_twi_pdata at91sam9x5_config = {
113	.clk_max_div = 7,
114	.clk_offset = 4,
115};
116
117static struct at91_twi_pdata sama5d4_config = {
118	.clk_max_div = 7,
119	.clk_offset = 4,
120	.has_hold_field = true,
121	.has_dig_filtr = true,
122};
123
124static struct at91_twi_pdata sama5d2_config = {
125	.clk_max_div = 7,
126	.clk_offset = 3,
127	.has_unre_flag = true,
128	.has_alt_cmd = true,
129	.has_hold_field = true,
130	.has_dig_filtr = true,
131	.has_adv_dig_filtr = true,
132	.has_ana_filtr = true,
133	.has_clear_cmd = false,	/* due to errata, CLEAR cmd is not working */
134};
135
136static struct at91_twi_pdata sam9x60_config = {
137	.clk_max_div = 7,
138	.clk_offset = 3,
139	.has_unre_flag = true,
140	.has_alt_cmd = true,
141	.has_hold_field = true,
142	.has_dig_filtr = true,
143	.has_adv_dig_filtr = true,
144	.has_ana_filtr = true,
145	.has_clear_cmd = true,
146};
147
148static const struct of_device_id atmel_twi_dt_ids[] = {
149	{
150		.compatible = "atmel,at91rm9200-i2c",
151		.data = &at91rm9200_config,
152	}, {
153		.compatible = "atmel,at91sam9260-i2c",
154		.data = &at91sam9260_config,
155	}, {
156		.compatible = "atmel,at91sam9261-i2c",
157		.data = &at91sam9261_config,
158	}, {
159		.compatible = "atmel,at91sam9g20-i2c",
160		.data = &at91sam9g20_config,
161	}, {
162		.compatible = "atmel,at91sam9g10-i2c",
163		.data = &at91sam9g10_config,
164	}, {
165		.compatible = "atmel,at91sam9x5-i2c",
166		.data = &at91sam9x5_config,
167	}, {
168		.compatible = "atmel,sama5d4-i2c",
169		.data = &sama5d4_config,
170	}, {
171		.compatible = "atmel,sama5d2-i2c",
172		.data = &sama5d2_config,
173	}, {
174		.compatible = "microchip,sam9x60-i2c",
175		.data = &sam9x60_config,
176	}, {
177		/* sentinel */
178	}
179};
180MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
181#endif
182
183static struct at91_twi_pdata *at91_twi_get_driver_data(
184					struct platform_device *pdev)
185{
186	if (pdev->dev.of_node) {
187		const struct of_device_id *match;
188		match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
189		if (!match)
190			return NULL;
191		return (struct at91_twi_pdata *)match->data;
192	}
193	return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
194}
195
196static int at91_twi_probe(struct platform_device *pdev)
197{
198	struct at91_twi_dev *dev;
199	struct resource *mem;
200	int rc;
201	u32 phy_addr;
202
203	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
204	if (!dev)
205		return -ENOMEM;
206
207	dev->dev = &pdev->dev;
208
209	dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
210	if (IS_ERR(dev->base))
211		return PTR_ERR(dev->base);
212	phy_addr = mem->start;
213
214	dev->pdata = at91_twi_get_driver_data(pdev);
215	if (!dev->pdata)
216		return -ENODEV;
217
218	dev->irq = platform_get_irq(pdev, 0);
219	if (dev->irq < 0)
220		return dev->irq;
221
222	platform_set_drvdata(pdev, dev);
223
224	dev->clk = devm_clk_get_enabled(dev->dev, NULL);
225	if (IS_ERR(dev->clk))
226		return dev_err_probe(dev->dev, PTR_ERR(dev->clk),
227				     "failed to enable clock\n");
228
229	snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
230	i2c_set_adapdata(&dev->adapter, dev);
231	dev->adapter.owner = THIS_MODULE;
232	dev->adapter.class = I2C_CLASS_DEPRECATED;
233	dev->adapter.dev.parent = dev->dev;
234	dev->adapter.nr = pdev->id;
235	dev->adapter.timeout = AT91_I2C_TIMEOUT;
236	dev->adapter.dev.of_node = pdev->dev.of_node;
237
238	dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
239
240	if (dev->slave_detected)
241		rc = at91_twi_probe_slave(pdev, phy_addr, dev);
242	else
243		rc = at91_twi_probe_master(pdev, phy_addr, dev);
244	if (rc)
245		return rc;
246
247	at91_init_twi_bus(dev);
248
249	pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
250	pm_runtime_use_autosuspend(dev->dev);
251	pm_runtime_set_active(dev->dev);
252	pm_runtime_enable(dev->dev);
253
254	rc = i2c_add_numbered_adapter(&dev->adapter);
255	if (rc) {
256		pm_runtime_disable(dev->dev);
257		pm_runtime_set_suspended(dev->dev);
258
259		return rc;
260	}
261
262	dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
263		 at91_twi_read(dev, AT91_TWI_VER));
264	return 0;
265}
266
267static void at91_twi_remove(struct platform_device *pdev)
268{
269	struct at91_twi_dev *dev = platform_get_drvdata(pdev);
270
271	i2c_del_adapter(&dev->adapter);
272
273	pm_runtime_disable(dev->dev);
274	pm_runtime_set_suspended(dev->dev);
275}
276
277static int __maybe_unused at91_twi_runtime_suspend(struct device *dev)
278{
279	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
280
281	clk_disable_unprepare(twi_dev->clk);
282
283	pinctrl_pm_select_sleep_state(dev);
284
285	return 0;
286}
287
288static int __maybe_unused at91_twi_runtime_resume(struct device *dev)
289{
290	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
291
292	pinctrl_pm_select_default_state(dev);
293
294	return clk_prepare_enable(twi_dev->clk);
295}
296
297static int __maybe_unused at91_twi_suspend_noirq(struct device *dev)
298{
299	if (!pm_runtime_status_suspended(dev))
300		at91_twi_runtime_suspend(dev);
301
302	return 0;
303}
304
305static int __maybe_unused at91_twi_resume_noirq(struct device *dev)
306{
307	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
308	int ret;
309
310	if (!pm_runtime_status_suspended(dev)) {
311		ret = at91_twi_runtime_resume(dev);
312		if (ret)
313			return ret;
314	}
315
316	pm_runtime_mark_last_busy(dev);
317	pm_request_autosuspend(dev);
318
319	at91_init_twi_bus(twi_dev);
320
321	return 0;
322}
323
324static const struct dev_pm_ops __maybe_unused at91_twi_pm = {
325	.suspend_noirq	= at91_twi_suspend_noirq,
326	.resume_noirq	= at91_twi_resume_noirq,
327	.runtime_suspend	= at91_twi_runtime_suspend,
328	.runtime_resume		= at91_twi_runtime_resume,
329};
330
331static struct platform_driver at91_twi_driver = {
332	.probe		= at91_twi_probe,
333	.remove_new	= at91_twi_remove,
334	.id_table	= at91_twi_devtypes,
335	.driver		= {
336		.name	= "at91_i2c",
337		.of_match_table = of_match_ptr(atmel_twi_dt_ids),
338		.pm	= pm_ptr(&at91_twi_pm),
339	},
340};
341
342static int __init at91_twi_init(void)
343{
344	return platform_driver_register(&at91_twi_driver);
345}
346
347static void __exit at91_twi_exit(void)
348{
349	platform_driver_unregister(&at91_twi_driver);
350}
351
352subsys_initcall(at91_twi_init);
353module_exit(at91_twi_exit);
354
355MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
356MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
357MODULE_LICENSE("GPL");
358MODULE_ALIAS("platform:at91_i2c");
359