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 | |
28 | unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg) |
29 | { |
30 | return readl_relaxed(dev->base + reg); |
31 | } |
32 | |
33 | void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) |
34 | { |
35 | writel_relaxed(val, dev->base + reg); |
36 | } |
37 | |
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 | |
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 | |
49 | void at91_twi_irq_restore(struct at91_twi_dev *dev) |
50 | { |
51 | at91_twi_write(dev, AT91_TWI_IER, val: dev->imr); |
52 | } |
53 | |
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 | |
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(matches: atmel_twi_dt_ids, node: 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 | |
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(dev: &pdev->dev, size: 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, index: 0, res: &mem); |
210 | if (IS_ERR(ptr: dev->base)) |
211 | return PTR_ERR(ptr: 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, data: dev); |
223 | |
224 | dev->clk = devm_clk_get_enabled(dev: dev->dev, NULL); |
225 | if (IS_ERR(ptr: dev->clk)) |
226 | return dev_err_probe(dev: dev->dev, err: PTR_ERR(ptr: dev->clk), |
227 | fmt: "failed to enable clock\n" ); |
228 | |
229 | snprintf(buf: dev->adapter.name, size: sizeof(dev->adapter.name), fmt: "AT91" ); |
230 | i2c_set_adapdata(adap: &dev->adapter, data: 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(dev: &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->dev, AUTOSUSPEND_TIMEOUT); |
250 | pm_runtime_use_autosuspend(dev: dev->dev); |
251 | pm_runtime_set_active(dev: dev->dev); |
252 | pm_runtime_enable(dev: dev->dev); |
253 | |
254 | rc = i2c_add_numbered_adapter(adap: &dev->adapter); |
255 | if (rc) { |
256 | pm_runtime_disable(dev: dev->dev); |
257 | pm_runtime_set_suspended(dev: 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 | |
267 | static void at91_twi_remove(struct platform_device *pdev) |
268 | { |
269 | struct at91_twi_dev *dev = platform_get_drvdata(pdev); |
270 | |
271 | i2c_del_adapter(adap: &dev->adapter); |
272 | |
273 | pm_runtime_disable(dev: dev->dev); |
274 | pm_runtime_set_suspended(dev: dev->dev); |
275 | } |
276 | |
277 | static 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(clk: twi_dev->clk); |
282 | |
283 | pinctrl_pm_select_sleep_state(dev); |
284 | |
285 | return 0; |
286 | } |
287 | |
288 | static 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(clk: twi_dev->clk); |
295 | } |
296 | |
297 | static 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 | |
305 | static 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(dev: twi_dev); |
320 | |
321 | return 0; |
322 | } |
323 | |
324 | static 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 | |
331 | static 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 | |
342 | static int __init at91_twi_init(void) |
343 | { |
344 | return platform_driver_register(&at91_twi_driver); |
345 | } |
346 | |
347 | static void __exit at91_twi_exit(void) |
348 | { |
349 | platform_driver_unregister(&at91_twi_driver); |
350 | } |
351 | |
352 | subsys_initcall(at91_twi_init); |
353 | module_exit(at91_twi_exit); |
354 | |
355 | MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>" ); |
356 | MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91" ); |
357 | MODULE_LICENSE("GPL" ); |
358 | MODULE_ALIAS("platform:at91_i2c" ); |
359 | |