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Linux/drivers/i2c/busses/i2c-designware-platdrv.c

  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/i2c.h>
 28 #include <linux/clk.h>
 29 #include <linux/clk-provider.h>
 30 #include <linux/errno.h>
 31 #include <linux/sched.h>
 32 #include <linux/err.h>
 33 #include <linux/interrupt.h>
 34 #include <linux/of.h>
 35 #include <linux/platform_device.h>
 36 #include <linux/pm.h>
 37 #include <linux/pm_runtime.h>
 38 #include <linux/io.h>
 39 #include <linux/slab.h>
 40 #include <linux/acpi.h>
 41 #include <linux/platform_data/i2c-designware.h>
 42 #include "i2c-designware-core.h"
 43 
 44 static struct i2c_algorithm i2c_dw_algo = {
 45         .master_xfer    = i2c_dw_xfer,
 46         .functionality  = i2c_dw_func,
 47 };
 48 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 49 {
 50         return clk_get_rate(dev->clk)/1000;
 51 }
 52 
 53 #ifdef CONFIG_ACPI
 54 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 55                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
 56 {
 57         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 58         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 59         union acpi_object *obj;
 60 
 61         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
 62                 return;
 63 
 64         obj = (union acpi_object *)buf.pointer;
 65         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
 66                 const union acpi_object *objs = obj->package.elements;
 67 
 68                 *hcnt = (u16)objs[0].integer.value;
 69                 *lcnt = (u16)objs[1].integer.value;
 70                 if (sda_hold)
 71                         *sda_hold = (u32)objs[2].integer.value;
 72         }
 73 
 74         kfree(buf.pointer);
 75 }
 76 
 77 static int dw_i2c_acpi_configure(struct platform_device *pdev)
 78 {
 79         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 80         const struct acpi_device_id *id;
 81 
 82         dev->adapter.nr = -1;
 83         dev->tx_fifo_depth = 32;
 84         dev->rx_fifo_depth = 32;
 85 
 86         /*
 87          * Try to get SDA hold time and *CNT values from an ACPI method if
 88          * it exists for both supported speed modes.
 89          */
 90         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
 91         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
 92                            &dev->sda_hold_time);
 93 
 94         /*
 95          * Provide a way for Designware I2C host controllers that are not
 96          * based on Intel LPSS to specify their input clock frequency via
 97          * id->driver_data.
 98          */
 99         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
100         if (id && id->driver_data)
101                 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
102                                         CLK_IS_ROOT, id->driver_data);
103 
104         return 0;
105 }
106 
107 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
108 {
109         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
110         const struct acpi_device_id *id;
111 
112         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
113         if (id && id->driver_data)
114                 clk_unregister(dev->clk);
115 }
116 
117 static const struct acpi_device_id dw_i2c_acpi_match[] = {
118         { "INT33C2", 0 },
119         { "INT33C3", 0 },
120         { "INT3432", 0 },
121         { "INT3433", 0 },
122         { "80860F41", 0 },
123         { "808622C1", 0 },
124         { "AMD0010", 133 * 1000 * 1000 },
125         { }
126 };
127 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
128 #else
129 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
130 {
131         return -ENODEV;
132 }
133 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
134 #endif
135 
136 static int dw_i2c_probe(struct platform_device *pdev)
137 {
138         struct dw_i2c_dev *dev;
139         struct i2c_adapter *adap;
140         struct resource *mem;
141         struct dw_i2c_platform_data *pdata;
142         int irq, r;
143         u32 clk_freq, ht = 0;
144 
145         irq = platform_get_irq(pdev, 0);
146         if (irq < 0)
147                 return irq;
148 
149         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
150         if (!dev)
151                 return -ENOMEM;
152 
153         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
154         dev->base = devm_ioremap_resource(&pdev->dev, mem);
155         if (IS_ERR(dev->base))
156                 return PTR_ERR(dev->base);
157 
158         init_completion(&dev->cmd_complete);
159         mutex_init(&dev->lock);
160         dev->dev = &pdev->dev;
161         dev->irq = irq;
162         platform_set_drvdata(pdev, dev);
163 
164         /* fast mode by default because of legacy reasons */
165         clk_freq = 400000;
166 
167         if (has_acpi_companion(&pdev->dev)) {
168                 dw_i2c_acpi_configure(pdev);
169         } else if (pdev->dev.of_node) {
170                 of_property_read_u32(pdev->dev.of_node,
171                                         "i2c-sda-hold-time-ns", &ht);
172 
173                 of_property_read_u32(pdev->dev.of_node,
174                                      "i2c-sda-falling-time-ns",
175                                      &dev->sda_falling_time);
176                 of_property_read_u32(pdev->dev.of_node,
177                                      "i2c-scl-falling-time-ns",
178                                      &dev->scl_falling_time);
179 
180                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
181                                      &clk_freq);
182 
183                 /* Only standard mode at 100kHz and fast mode at 400kHz
184                  * are supported.
185                  */
186                 if (clk_freq != 100000 && clk_freq != 400000) {
187                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
188                         return -EINVAL;
189                 }
190         } else {
191                 pdata = dev_get_platdata(&pdev->dev);
192                 if (pdata)
193                         clk_freq = pdata->i2c_scl_freq;
194         }
195 
196         r = i2c_dw_eval_lock_support(dev);
197         if (r)
198                 return r;
199 
200         dev->functionality =
201                 I2C_FUNC_I2C |
202                 I2C_FUNC_10BIT_ADDR |
203                 I2C_FUNC_SMBUS_BYTE |
204                 I2C_FUNC_SMBUS_BYTE_DATA |
205                 I2C_FUNC_SMBUS_WORD_DATA |
206                 I2C_FUNC_SMBUS_I2C_BLOCK;
207         if (clk_freq == 100000)
208                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
209                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
210         else
211                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
212                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
213 
214         dev->clk = devm_clk_get(&pdev->dev, NULL);
215         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
216         if (IS_ERR(dev->clk))
217                 return PTR_ERR(dev->clk);
218         clk_prepare_enable(dev->clk);
219 
220         if (!dev->sda_hold_time && ht) {
221                 u32 ic_clk = dev->get_clk_rate_khz(dev);
222 
223                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
224                                              1000000);
225         }
226 
227         if (!dev->tx_fifo_depth) {
228                 u32 param1 = i2c_dw_read_comp_param(dev);
229 
230                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
231                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
232                 dev->adapter.nr = pdev->id;
233         }
234         r = i2c_dw_init(dev);
235         if (r)
236                 return r;
237 
238         i2c_dw_disable_int(dev);
239         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
240                         pdev->name, dev);
241         if (r) {
242                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
243                 return r;
244         }
245 
246         adap = &dev->adapter;
247         i2c_set_adapdata(adap, dev);
248         adap->owner = THIS_MODULE;
249         adap->class = I2C_CLASS_DEPRECATED;
250         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
251                         sizeof(adap->name));
252         adap->algo = &i2c_dw_algo;
253         adap->dev.parent = &pdev->dev;
254         adap->dev.of_node = pdev->dev.of_node;
255 
256         r = i2c_add_numbered_adapter(adap);
257         if (r) {
258                 dev_err(&pdev->dev, "failure adding adapter\n");
259                 return r;
260         }
261 
262         if (dev->pm_runtime_disabled) {
263                 pm_runtime_forbid(&pdev->dev);
264         } else {
265                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
266                 pm_runtime_use_autosuspend(&pdev->dev);
267                 pm_runtime_set_active(&pdev->dev);
268                 pm_runtime_enable(&pdev->dev);
269         }
270 
271         return 0;
272 }
273 
274 static int dw_i2c_remove(struct platform_device *pdev)
275 {
276         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
277 
278         pm_runtime_get_sync(&pdev->dev);
279 
280         i2c_del_adapter(&dev->adapter);
281 
282         i2c_dw_disable(dev);
283 
284         pm_runtime_dont_use_autosuspend(&pdev->dev);
285         pm_runtime_put_sync(&pdev->dev);
286         pm_runtime_disable(&pdev->dev);
287 
288         if (has_acpi_companion(&pdev->dev))
289                 dw_i2c_acpi_unconfigure(pdev);
290 
291         return 0;
292 }
293 
294 #ifdef CONFIG_OF
295 static const struct of_device_id dw_i2c_of_match[] = {
296         { .compatible = "snps,designware-i2c", },
297         {},
298 };
299 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
300 #endif
301 
302 #ifdef CONFIG_PM_SLEEP
303 static int dw_i2c_prepare(struct device *dev)
304 {
305         return pm_runtime_suspended(dev);
306 }
307 
308 static void dw_i2c_complete(struct device *dev)
309 {
310         if (dev->power.direct_complete)
311                 pm_request_resume(dev);
312 }
313 #else
314 #define dw_i2c_prepare  NULL
315 #define dw_i2c_complete NULL
316 #endif
317 
318 #ifdef CONFIG_PM
319 static int dw_i2c_suspend(struct device *dev)
320 {
321         struct platform_device *pdev = to_platform_device(dev);
322         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
323 
324         i2c_dw_disable(i_dev);
325         clk_disable_unprepare(i_dev->clk);
326 
327         return 0;
328 }
329 
330 static int dw_i2c_resume(struct device *dev)
331 {
332         struct platform_device *pdev = to_platform_device(dev);
333         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
334 
335         clk_prepare_enable(i_dev->clk);
336 
337         if (!i_dev->pm_runtime_disabled)
338                 i2c_dw_init(i_dev);
339 
340         return 0;
341 }
342 
343 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
344         .prepare = dw_i2c_prepare,
345         .complete = dw_i2c_complete,
346         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_suspend, dw_i2c_resume)
347         SET_RUNTIME_PM_OPS(dw_i2c_suspend, dw_i2c_resume, NULL)
348 };
349 
350 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
351 #else
352 #define DW_I2C_DEV_PMOPS NULL
353 #endif
354 
355 /* work with hotplug and coldplug */
356 MODULE_ALIAS("platform:i2c_designware");
357 
358 static struct platform_driver dw_i2c_driver = {
359         .probe = dw_i2c_probe,
360         .remove = dw_i2c_remove,
361         .driver         = {
362                 .name   = "i2c_designware",
363                 .of_match_table = of_match_ptr(dw_i2c_of_match),
364                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
365                 .pm     = DW_I2C_DEV_PMOPS,
366         },
367 };
368 
369 static int __init dw_i2c_init_driver(void)
370 {
371         return platform_driver_register(&dw_i2c_driver);
372 }
373 subsys_initcall(dw_i2c_init_driver);
374 
375 static void __exit dw_i2c_exit_driver(void)
376 {
377         platform_driver_unregister(&dw_i2c_driver);
378 }
379 module_exit(dw_i2c_exit_driver);
380 
381 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
382 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
383 MODULE_LICENSE("GPL");
384 

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