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
at91_twi_read(struct at91_twi_dev * dev,unsigned reg)28 unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
29 {
30 return readl_relaxed(dev->base + reg);
31 }
32
at91_twi_write(struct at91_twi_dev * dev,unsigned reg,unsigned val)33 void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
34 {
35 writel_relaxed(val, dev->base + reg);
36 }
37
at91_disable_twi_interrupts(struct at91_twi_dev * dev)38 void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
39 {
40 at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
41 }
42
at91_twi_irq_save(struct at91_twi_dev * dev)43 void 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
at91_twi_irq_restore(struct at91_twi_dev * dev)49 void at91_twi_irq_restore(struct at91_twi_dev *dev)
50 {
51 at91_twi_write(dev, AT91_TWI_IER, dev->imr);
52 }
53
at91_init_twi_bus(struct at91_twi_dev * dev)54 void 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
64 static struct at91_twi_pdata at91rm9200_config = {
65 .clk_max_div = 5,
66 .clk_offset = 3,
67 .has_unre_flag = true,
68 };
69
70 static struct at91_twi_pdata at91sam9261_config = {
71 .clk_max_div = 5,
72 .clk_offset = 4,
73 };
74
75 static struct at91_twi_pdata at91sam9260_config = {
76 .clk_max_div = 7,
77 .clk_offset = 4,
78 };
79
80 static struct at91_twi_pdata at91sam9g20_config = {
81 .clk_max_div = 7,
82 .clk_offset = 4,
83 };
84
85 static struct at91_twi_pdata at91sam9g10_config = {
86 .clk_max_div = 7,
87 .clk_offset = 4,
88 };
89
90 static 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)
112 static struct at91_twi_pdata at91sam9x5_config = {
113 .clk_max_div = 7,
114 .clk_offset = 4,
115 };
116
117 static 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
124 static 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
136 static 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
148 static 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 };
180 MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
181 #endif
182
at91_twi_get_driver_data(struct platform_device * pdev)183 static 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
at91_twi_probe(struct platform_device * pdev)196 static 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(dev->dev, NULL);
225 if (IS_ERR(dev->clk))
226 return dev_err_probe(dev->dev, PTR_ERR(dev->clk), "no clock defined\n");
227
228 clk_prepare_enable(dev->clk);
229
230 snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
231 i2c_set_adapdata(&dev->adapter, dev);
232 dev->adapter.owner = THIS_MODULE;
233 dev->adapter.class = I2C_CLASS_DEPRECATED;
234 dev->adapter.dev.parent = dev->dev;
235 dev->adapter.nr = pdev->id;
236 dev->adapter.timeout = AT91_I2C_TIMEOUT;
237 dev->adapter.dev.of_node = pdev->dev.of_node;
238
239 dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
240
241 if (dev->slave_detected)
242 rc = at91_twi_probe_slave(pdev, phy_addr, dev);
243 else
244 rc = at91_twi_probe_master(pdev, phy_addr, dev);
245 if (rc)
246 return rc;
247
248 at91_init_twi_bus(dev);
249
250 pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
251 pm_runtime_use_autosuspend(dev->dev);
252 pm_runtime_set_active(dev->dev);
253 pm_runtime_enable(dev->dev);
254
255 rc = i2c_add_numbered_adapter(&dev->adapter);
256 if (rc) {
257 clk_disable_unprepare(dev->clk);
258
259 pm_runtime_disable(dev->dev);
260 pm_runtime_set_suspended(dev->dev);
261
262 return rc;
263 }
264
265 dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
266 at91_twi_read(dev, AT91_TWI_VER));
267 return 0;
268 }
269
at91_twi_remove(struct platform_device * pdev)270 static void at91_twi_remove(struct platform_device *pdev)
271 {
272 struct at91_twi_dev *dev = platform_get_drvdata(pdev);
273
274 i2c_del_adapter(&dev->adapter);
275 clk_disable_unprepare(dev->clk);
276
277 pm_runtime_disable(dev->dev);
278 pm_runtime_set_suspended(dev->dev);
279 }
280
at91_twi_runtime_suspend(struct device * dev)281 static int __maybe_unused at91_twi_runtime_suspend(struct device *dev)
282 {
283 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
284
285 clk_disable_unprepare(twi_dev->clk);
286
287 pinctrl_pm_select_sleep_state(dev);
288
289 return 0;
290 }
291
at91_twi_runtime_resume(struct device * dev)292 static int __maybe_unused at91_twi_runtime_resume(struct device *dev)
293 {
294 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
295
296 pinctrl_pm_select_default_state(dev);
297
298 return clk_prepare_enable(twi_dev->clk);
299 }
300
at91_twi_suspend_noirq(struct device * dev)301 static int __maybe_unused at91_twi_suspend_noirq(struct device *dev)
302 {
303 if (!pm_runtime_status_suspended(dev))
304 at91_twi_runtime_suspend(dev);
305
306 return 0;
307 }
308
at91_twi_resume_noirq(struct device * dev)309 static int __maybe_unused at91_twi_resume_noirq(struct device *dev)
310 {
311 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
312 int ret;
313
314 if (!pm_runtime_status_suspended(dev)) {
315 ret = at91_twi_runtime_resume(dev);
316 if (ret)
317 return ret;
318 }
319
320 pm_runtime_mark_last_busy(dev);
321 pm_request_autosuspend(dev);
322
323 at91_init_twi_bus(twi_dev);
324
325 return 0;
326 }
327
328 static const struct dev_pm_ops __maybe_unused at91_twi_pm = {
329 .suspend_noirq = at91_twi_suspend_noirq,
330 .resume_noirq = at91_twi_resume_noirq,
331 .runtime_suspend = at91_twi_runtime_suspend,
332 .runtime_resume = at91_twi_runtime_resume,
333 };
334
335 static struct platform_driver at91_twi_driver = {
336 .probe = at91_twi_probe,
337 .remove_new = at91_twi_remove,
338 .id_table = at91_twi_devtypes,
339 .driver = {
340 .name = "at91_i2c",
341 .of_match_table = of_match_ptr(atmel_twi_dt_ids),
342 .pm = pm_ptr(&at91_twi_pm),
343 },
344 };
345
at91_twi_init(void)346 static int __init at91_twi_init(void)
347 {
348 return platform_driver_register(&at91_twi_driver);
349 }
350
at91_twi_exit(void)351 static void __exit at91_twi_exit(void)
352 {
353 platform_driver_unregister(&at91_twi_driver);
354 }
355
356 subsys_initcall(at91_twi_init);
357 module_exit(at91_twi_exit);
358
359 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
360 MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
361 MODULE_LICENSE("GPL");
362 MODULE_ALIAS("platform:at91_i2c");
363
