1 /*
2 * Synopsys DesignWare I2C adapter driver (master only).
3 *
4 * Based on the TI DAVINCI I2C adapter driver.
5 *
6 * Copyright (C) 2006 Texas Instruments.
7 * Copyright (C) 2007 MontaVista Software Inc.
8 * Copyright (C) 2009 Provigent Ltd.
9 *
10 * ----------------------------------------------------------------------------
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 * ----------------------------------------------------------------------------
22 *
23 */
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/delay.h>
27 #include <linux/dmi.h>
28 #include <linux/i2c.h>
29 #include <linux/clk.h>
30 #include <linux/clk-provider.h>
31 #include <linux/errno.h>
32 #include <linux/sched.h>
33 #include <linux/err.h>
34 #include <linux/interrupt.h>
35 #include <linux/of.h>
36 #include <linux/platform_device.h>
37 #include <linux/pm.h>
38 #include <linux/pm_runtime.h>
39 #include <linux/io.h>
40 #include <linux/slab.h>
41 #include <linux/acpi.h>
42 #include <linux/platform_data/i2c-designware.h>
43 #include "i2c-designware-core.h"
44
45 static struct i2c_algorithm i2c_dw_algo = {
46 .master_xfer = i2c_dw_xfer,
47 .functionality = i2c_dw_func,
48 };
i2c_dw_get_clk_rate_khz(struct dw_i2c_dev * dev)49 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
50 {
51 return clk_get_rate(dev->clk)/1000;
52 }
53
54 #ifdef CONFIG_ACPI
55 /*
56 * The HCNT/LCNT information coming from ACPI should be the most accurate
57 * for given platform. However, some systems get it wrong. On such systems
58 * we get better results by calculating those based on the input clock.
59 */
60 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
61 {
62 .ident = "Dell Inspiron 7348",
63 .matches = {
64 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
65 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
66 },
67 },
68 { }
69 };
70
dw_i2c_acpi_params(struct platform_device * pdev,char method[],u16 * hcnt,u16 * lcnt,u32 * sda_hold)71 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
72 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
73 {
74 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
75 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
76 union acpi_object *obj;
77
78 if (dmi_check_system(dw_i2c_no_acpi_params))
79 return;
80
81 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
82 return;
83
84 obj = (union acpi_object *)buf.pointer;
85 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
86 const union acpi_object *objs = obj->package.elements;
87
88 *hcnt = (u16)objs[0].integer.value;
89 *lcnt = (u16)objs[1].integer.value;
90 if (sda_hold)
91 *sda_hold = (u32)objs[2].integer.value;
92 }
93
94 kfree(buf.pointer);
95 }
96
dw_i2c_acpi_configure(struct platform_device * pdev)97 static int dw_i2c_acpi_configure(struct platform_device *pdev)
98 {
99 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
100 const struct acpi_device_id *id;
101
102 dev->adapter.nr = -1;
103 dev->tx_fifo_depth = 32;
104 dev->rx_fifo_depth = 32;
105
106 /*
107 * Try to get SDA hold time and *CNT values from an ACPI method if
108 * it exists for both supported speed modes.
109 */
110 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
111 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
112 &dev->sda_hold_time);
113
114 /*
115 * Provide a way for Designware I2C host controllers that are not
116 * based on Intel LPSS to specify their input clock frequency via
117 * id->driver_data.
118 */
119 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
120 if (id && id->driver_data)
121 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
122 CLK_IS_ROOT, id->driver_data);
123
124 return 0;
125 }
126
dw_i2c_acpi_unconfigure(struct platform_device * pdev)127 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
128 {
129 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
130 const struct acpi_device_id *id;
131
132 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
133 if (id && id->driver_data)
134 clk_unregister(dev->clk);
135 }
136
137 static const struct acpi_device_id dw_i2c_acpi_match[] = {
138 { "INT33C2", 0 },
139 { "INT33C3", 0 },
140 { "INT3432", 0 },
141 { "INT3433", 0 },
142 { "80860F41", 0 },
143 { "808622C1", 0 },
144 { "AMD0010", 133 * 1000 * 1000 },
145 { }
146 };
147 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
148 #else
dw_i2c_acpi_configure(struct platform_device * pdev)149 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
150 {
151 return -ENODEV;
152 }
dw_i2c_acpi_unconfigure(struct platform_device * pdev)153 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
154 #endif
155
dw_i2c_probe(struct platform_device * pdev)156 static int dw_i2c_probe(struct platform_device *pdev)
157 {
158 struct dw_i2c_dev *dev;
159 struct i2c_adapter *adap;
160 struct resource *mem;
161 struct dw_i2c_platform_data *pdata;
162 int irq, r;
163 u32 clk_freq, ht = 0;
164
165 irq = platform_get_irq(pdev, 0);
166 if (irq < 0) {
167 dev_err(&pdev->dev, "no irq resource?\n");
168 return irq; /* -ENXIO */
169 }
170
171 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
172 if (!dev)
173 return -ENOMEM;
174
175 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
176 dev->base = devm_ioremap_resource(&pdev->dev, mem);
177 if (IS_ERR(dev->base))
178 return PTR_ERR(dev->base);
179
180 init_completion(&dev->cmd_complete);
181 mutex_init(&dev->lock);
182 dev->dev = &pdev->dev;
183 dev->irq = irq;
184 platform_set_drvdata(pdev, dev);
185
186 /* fast mode by default because of legacy reasons */
187 clk_freq = 400000;
188
189 if (ACPI_COMPANION(&pdev->dev)) {
190 dw_i2c_acpi_configure(pdev);
191 } else if (pdev->dev.of_node) {
192 of_property_read_u32(pdev->dev.of_node,
193 "i2c-sda-hold-time-ns", &ht);
194
195 of_property_read_u32(pdev->dev.of_node,
196 "i2c-sda-falling-time-ns",
197 &dev->sda_falling_time);
198 of_property_read_u32(pdev->dev.of_node,
199 "i2c-scl-falling-time-ns",
200 &dev->scl_falling_time);
201
202 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
203 &clk_freq);
204
205 /* Only standard mode at 100kHz and fast mode at 400kHz
206 * are supported.
207 */
208 if (clk_freq != 100000 && clk_freq != 400000) {
209 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
210 return -EINVAL;
211 }
212 } else {
213 pdata = dev_get_platdata(&pdev->dev);
214 if (pdata)
215 clk_freq = pdata->i2c_scl_freq;
216 }
217
218 dev->functionality =
219 I2C_FUNC_I2C |
220 I2C_FUNC_10BIT_ADDR |
221 I2C_FUNC_SMBUS_BYTE |
222 I2C_FUNC_SMBUS_BYTE_DATA |
223 I2C_FUNC_SMBUS_WORD_DATA |
224 I2C_FUNC_SMBUS_I2C_BLOCK;
225 if (clk_freq == 100000)
226 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
227 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
228 else
229 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
230 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
231
232 dev->clk = devm_clk_get(&pdev->dev, NULL);
233 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
234 if (IS_ERR(dev->clk))
235 return PTR_ERR(dev->clk);
236 clk_prepare_enable(dev->clk);
237
238 if (!dev->sda_hold_time && ht) {
239 u32 ic_clk = dev->get_clk_rate_khz(dev);
240
241 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
242 1000000);
243 }
244
245 if (!dev->tx_fifo_depth) {
246 u32 param1 = i2c_dw_read_comp_param(dev);
247
248 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
249 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
250 dev->adapter.nr = pdev->id;
251 }
252 r = i2c_dw_init(dev);
253 if (r)
254 return r;
255
256 i2c_dw_disable_int(dev);
257 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
258 pdev->name, dev);
259 if (r) {
260 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
261 return r;
262 }
263
264 adap = &dev->adapter;
265 i2c_set_adapdata(adap, dev);
266 adap->owner = THIS_MODULE;
267 adap->class = I2C_CLASS_DEPRECATED;
268 strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
269 sizeof(adap->name));
270 adap->algo = &i2c_dw_algo;
271 adap->dev.parent = &pdev->dev;
272 adap->dev.of_node = pdev->dev.of_node;
273
274 r = i2c_add_numbered_adapter(adap);
275 if (r) {
276 dev_err(&pdev->dev, "failure adding adapter\n");
277 return r;
278 }
279
280 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
281 pm_runtime_use_autosuspend(&pdev->dev);
282 pm_runtime_set_active(&pdev->dev);
283 pm_runtime_enable(&pdev->dev);
284
285 return 0;
286 }
287
dw_i2c_remove(struct platform_device * pdev)288 static int dw_i2c_remove(struct platform_device *pdev)
289 {
290 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
291
292 pm_runtime_get_sync(&pdev->dev);
293
294 i2c_del_adapter(&dev->adapter);
295
296 i2c_dw_disable(dev);
297
298 pm_runtime_put(&pdev->dev);
299 pm_runtime_disable(&pdev->dev);
300
301 if (ACPI_COMPANION(&pdev->dev))
302 dw_i2c_acpi_unconfigure(pdev);
303
304 return 0;
305 }
306
307 #ifdef CONFIG_OF
308 static const struct of_device_id dw_i2c_of_match[] = {
309 { .compatible = "snps,designware-i2c", },
310 {},
311 };
312 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
313 #endif
314
315 #ifdef CONFIG_PM
dw_i2c_suspend(struct device * dev)316 static int dw_i2c_suspend(struct device *dev)
317 {
318 struct platform_device *pdev = to_platform_device(dev);
319 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
320
321 i2c_dw_disable(i_dev);
322 clk_disable_unprepare(i_dev->clk);
323
324 return 0;
325 }
326
dw_i2c_resume(struct device * dev)327 static int dw_i2c_resume(struct device *dev)
328 {
329 struct platform_device *pdev = to_platform_device(dev);
330 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
331
332 clk_prepare_enable(i_dev->clk);
333 i2c_dw_init(i_dev);
334
335 return 0;
336 }
337 #endif
338
339 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
340 dw_i2c_resume, NULL);
341
342 /* work with hotplug and coldplug */
343 MODULE_ALIAS("platform:i2c_designware");
344
345 static struct platform_driver dw_i2c_driver = {
346 .probe = dw_i2c_probe,
347 .remove = dw_i2c_remove,
348 .driver = {
349 .name = "i2c_designware",
350 .owner = THIS_MODULE,
351 .of_match_table = of_match_ptr(dw_i2c_of_match),
352 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
353 .pm = &dw_i2c_dev_pm_ops,
354 },
355 };
356
dw_i2c_init_driver(void)357 static int __init dw_i2c_init_driver(void)
358 {
359 return platform_driver_register(&dw_i2c_driver);
360 }
361 subsys_initcall(dw_i2c_init_driver);
362
dw_i2c_exit_driver(void)363 static void __exit dw_i2c_exit_driver(void)
364 {
365 platform_driver_unregister(&dw_i2c_driver);
366 }
367 module_exit(dw_i2c_exit_driver);
368
369 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
370 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
371 MODULE_LICENSE("GPL");
372