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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/of_device.h>
23#include <linux/platform_device.h>
24#include <linux/pm_runtime.h>
25#include <linux/pinctrl/consumer.h>
26
27#include "i2c-at91.h"
28
29unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
30{
31 return readl_relaxed(dev->base + reg);
32}
33
34void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
35{
36 writel_relaxed(val, dev->base + reg);
37}
38
39void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
40{
41 at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
42}
43
44void at91_twi_irq_save(struct at91_twi_dev *dev)
45{
46 dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
47 at91_disable_twi_interrupts(dev);
48}
49
50void at91_twi_irq_restore(struct at91_twi_dev *dev)
51{
52 at91_twi_write(dev, AT91_TWI_IER, dev->imr);
53}
54
55void at91_init_twi_bus(struct at91_twi_dev *dev)
56{
57 at91_disable_twi_interrupts(dev);
58 at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
59 if (dev->slave_detected)
60 at91_init_twi_bus_slave(dev);
61 else
62 at91_init_twi_bus_master(dev);
63}
64
65static struct at91_twi_pdata at91rm9200_config = {
66 .clk_max_div = 5,
67 .clk_offset = 3,
68 .has_unre_flag = true,
69};
70
71static struct at91_twi_pdata at91sam9261_config = {
72 .clk_max_div = 5,
73 .clk_offset = 4,
74};
75
76static struct at91_twi_pdata at91sam9260_config = {
77 .clk_max_div = 7,
78 .clk_offset = 4,
79};
80
81static struct at91_twi_pdata at91sam9g20_config = {
82 .clk_max_div = 7,
83 .clk_offset = 4,
84};
85
86static struct at91_twi_pdata at91sam9g10_config = {
87 .clk_max_div = 7,
88 .clk_offset = 4,
89};
90
91static const struct platform_device_id at91_twi_devtypes[] = {
92 {
93 .name = "i2c-at91rm9200",
94 .driver_data = (unsigned long) &at91rm9200_config,
95 }, {
96 .name = "i2c-at91sam9261",
97 .driver_data = (unsigned long) &at91sam9261_config,
98 }, {
99 .name = "i2c-at91sam9260",
100 .driver_data = (unsigned long) &at91sam9260_config,
101 }, {
102 .name = "i2c-at91sam9g20",
103 .driver_data = (unsigned long) &at91sam9g20_config,
104 }, {
105 .name = "i2c-at91sam9g10",
106 .driver_data = (unsigned long) &at91sam9g10_config,
107 }, {
108 /* sentinel */
109 }
110};
111
112#if defined(CONFIG_OF)
113static struct at91_twi_pdata at91sam9x5_config = {
114 .clk_max_div = 7,
115 .clk_offset = 4,
116};
117
118static struct at91_twi_pdata sama5d4_config = {
119 .clk_max_div = 7,
120 .clk_offset = 4,
121 .has_hold_field = true,
122 .has_dig_filtr = true,
123};
124
125static struct at91_twi_pdata sama5d2_config = {
126 .clk_max_div = 7,
127 .clk_offset = 3,
128 .has_unre_flag = true,
129 .has_alt_cmd = true,
130 .has_hold_field = true,
131 .has_dig_filtr = true,
132 .has_adv_dig_filtr = true,
133 .has_ana_filtr = true,
134 .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */
135};
136
137static struct at91_twi_pdata sam9x60_config = {
138 .clk_max_div = 7,
139 .clk_offset = 3,
140 .has_unre_flag = true,
141 .has_alt_cmd = true,
142 .has_hold_field = true,
143 .has_dig_filtr = true,
144 .has_adv_dig_filtr = true,
145 .has_ana_filtr = true,
146 .has_clear_cmd = true,
147};
148
149static const struct of_device_id atmel_twi_dt_ids[] = {
150 {
151 .compatible = "atmel,at91rm9200-i2c",
152 .data = &at91rm9200_config,
153 }, {
154 .compatible = "atmel,at91sam9260-i2c",
155 .data = &at91sam9260_config,
156 }, {
157 .compatible = "atmel,at91sam9261-i2c",
158 .data = &at91sam9261_config,
159 }, {
160 .compatible = "atmel,at91sam9g20-i2c",
161 .data = &at91sam9g20_config,
162 }, {
163 .compatible = "atmel,at91sam9g10-i2c",
164 .data = &at91sam9g10_config,
165 }, {
166 .compatible = "atmel,at91sam9x5-i2c",
167 .data = &at91sam9x5_config,
168 }, {
169 .compatible = "atmel,sama5d4-i2c",
170 .data = &sama5d4_config,
171 }, {
172 .compatible = "atmel,sama5d2-i2c",
173 .data = &sama5d2_config,
174 }, {
175 .compatible = "microchip,sam9x60-i2c",
176 .data = &sam9x60_config,
177 }, {
178 /* sentinel */
179 }
180};
181MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
182#endif
183
184static struct at91_twi_pdata *at91_twi_get_driver_data(
185 struct platform_device *pdev)
186{
187 if (pdev->dev.of_node) {
188 const struct of_device_id *match;
189 match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
190 if (!match)
191 return NULL;
192 return (struct at91_twi_pdata *)match->data;
193 }
194 return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
195}
196
197static int at91_twi_probe(struct platform_device *pdev)
198{
199 struct at91_twi_dev *dev;
200 struct resource *mem;
201 int rc;
202 u32 phy_addr;
203
204 dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
205 if (!dev)
206 return -ENOMEM;
207
208 dev->dev = &pdev->dev;
209
210 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
211 if (!mem)
212 return -ENODEV;
213 phy_addr = mem->start;
214
215 dev->pdata = at91_twi_get_driver_data(pdev);
216 if (!dev->pdata)
217 return -ENODEV;
218
219 dev->base = devm_ioremap_resource(&pdev->dev, mem);
220 if (IS_ERR(dev->base))
221 return PTR_ERR(dev->base);
222
223 dev->irq = platform_get_irq(pdev, 0);
224 if (dev->irq < 0)
225 return dev->irq;
226
227 platform_set_drvdata(pdev, dev);
228
229 dev->clk = devm_clk_get(dev->dev, NULL);
230 if (IS_ERR(dev->clk)) {
231 dev_err(dev->dev, "no clock defined\n");
232 return -ENODEV;
233 }
234 clk_prepare_enable(dev->clk);
235
236 snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
237 i2c_set_adapdata(&dev->adapter, dev);
238 dev->adapter.owner = THIS_MODULE;
239 dev->adapter.class = I2C_CLASS_DEPRECATED;
240 dev->adapter.dev.parent = dev->dev;
241 dev->adapter.nr = pdev->id;
242 dev->adapter.timeout = AT91_I2C_TIMEOUT;
243 dev->adapter.dev.of_node = pdev->dev.of_node;
244
245 dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
246
247 if (dev->slave_detected)
248 rc = at91_twi_probe_slave(pdev, phy_addr, dev);
249 else
250 rc = at91_twi_probe_master(pdev, phy_addr, dev);
251 if (rc)
252 return rc;
253
254 at91_init_twi_bus(dev);
255
256 pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
257 pm_runtime_use_autosuspend(dev->dev);
258 pm_runtime_set_active(dev->dev);
259 pm_runtime_enable(dev->dev);
260
261 rc = i2c_add_numbered_adapter(&dev->adapter);
262 if (rc) {
263 clk_disable_unprepare(dev->clk);
264
265 pm_runtime_disable(dev->dev);
266 pm_runtime_set_suspended(dev->dev);
267
268 return rc;
269 }
270
271 dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
272 at91_twi_read(dev, AT91_TWI_VER));
273 return 0;
274}
275
276static int at91_twi_remove(struct platform_device *pdev)
277{
278 struct at91_twi_dev *dev = platform_get_drvdata(pdev);
279
280 i2c_del_adapter(&dev->adapter);
281 clk_disable_unprepare(dev->clk);
282
283 pm_runtime_disable(dev->dev);
284 pm_runtime_set_suspended(dev->dev);
285
286 return 0;
287}
288
289static int __maybe_unused at91_twi_runtime_suspend(struct device *dev)
290{
291 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
292
293 clk_disable_unprepare(twi_dev->clk);
294
295 pinctrl_pm_select_sleep_state(dev);
296
297 return 0;
298}
299
300static int __maybe_unused at91_twi_runtime_resume(struct device *dev)
301{
302 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
303
304 pinctrl_pm_select_default_state(dev);
305
306 return clk_prepare_enable(twi_dev->clk);
307}
308
309static int __maybe_unused at91_twi_suspend_noirq(struct device *dev)
310{
311 if (!pm_runtime_status_suspended(dev))
312 at91_twi_runtime_suspend(dev);
313
314 return 0;
315}
316
317static int __maybe_unused at91_twi_resume_noirq(struct device *dev)
318{
319 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
320 int ret;
321
322 if (!pm_runtime_status_suspended(dev)) {
323 ret = at91_twi_runtime_resume(dev);
324 if (ret)
325 return ret;
326 }
327
328 pm_runtime_mark_last_busy(dev);
329 pm_request_autosuspend(dev);
330
331 at91_init_twi_bus(twi_dev);
332
333 return 0;
334}
335
336static const struct dev_pm_ops __maybe_unused at91_twi_pm = {
337 .suspend_noirq = at91_twi_suspend_noirq,
338 .resume_noirq = at91_twi_resume_noirq,
339 .runtime_suspend = at91_twi_runtime_suspend,
340 .runtime_resume = at91_twi_runtime_resume,
341};
342
343static struct platform_driver at91_twi_driver = {
344 .probe = at91_twi_probe,
345 .remove = at91_twi_remove,
346 .id_table = at91_twi_devtypes,
347 .driver = {
348 .name = "at91_i2c",
349 .of_match_table = of_match_ptr(atmel_twi_dt_ids),
350 .pm = pm_ptr(&at91_twi_pm),
351 },
352};
353
354static int __init at91_twi_init(void)
355{
356 return platform_driver_register(&at91_twi_driver);
357}
358
359static void __exit at91_twi_exit(void)
360{
361 platform_driver_unregister(&at91_twi_driver);
362}
363
364subsys_initcall(at91_twi_init);
365module_exit(at91_twi_exit);
366
367MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
368MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
369MODULE_LICENSE("GPL");
370MODULE_ALIAS("platform:at91_i2c");