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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/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 u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 46 {
 47         return clk_get_rate(dev->clk)/1000;
 48 }
 49 
 50 #ifdef CONFIG_ACPI
 51 /*
 52  * The HCNT/LCNT information coming from ACPI should be the most accurate
 53  * for given platform. However, some systems get it wrong. On such systems
 54  * we get better results by calculating those based on the input clock.
 55  */
 56 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
 57         {
 58                 .ident = "Dell Inspiron 7348",
 59                 .matches = {
 60                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 61                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
 62                 },
 63         },
 64         { }
 65 };
 66 
 67 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 68                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
 69 {
 70         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 71         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 72         union acpi_object *obj;
 73 
 74         if (dmi_check_system(dw_i2c_no_acpi_params))
 75                 return;
 76 
 77         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
 78                 return;
 79 
 80         obj = (union acpi_object *)buf.pointer;
 81         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
 82                 const union acpi_object *objs = obj->package.elements;
 83 
 84                 *hcnt = (u16)objs[0].integer.value;
 85                 *lcnt = (u16)objs[1].integer.value;
 86                 if (sda_hold)
 87                         *sda_hold = (u32)objs[2].integer.value;
 88         }
 89 
 90         kfree(buf.pointer);
 91 }
 92 
 93 static int dw_i2c_acpi_configure(struct platform_device *pdev)
 94 {
 95         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 96         const struct acpi_device_id *id;
 97 
 98         dev->adapter.nr = -1;
 99         dev->tx_fifo_depth = 32;
100         dev->rx_fifo_depth = 32;
101 
102         /*
103          * Try to get SDA hold time and *CNT values from an ACPI method if
104          * it exists for both supported speed modes.
105          */
106         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
107         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
108                            &dev->sda_hold_time);
109 
110         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
111         if (id && id->driver_data)
112                 dev->accessor_flags |= (u32)id->driver_data;
113 
114         return 0;
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", ACCESS_INTR_MASK },
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 #endif
134 
135 static int dw_i2c_plat_probe(struct platform_device *pdev)
136 {
137         struct dw_i2c_dev *dev;
138         struct i2c_adapter *adap;
139         struct resource *mem;
140         struct dw_i2c_platform_data *pdata;
141         int irq, r;
142         u32 clk_freq, ht = 0;
143 
144         irq = platform_get_irq(pdev, 0);
145         if (irq < 0)
146                 return irq;
147 
148         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
149         if (!dev)
150                 return -ENOMEM;
151 
152         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
153         dev->base = devm_ioremap_resource(&pdev->dev, mem);
154         if (IS_ERR(dev->base))
155                 return PTR_ERR(dev->base);
156 
157         dev->dev = &pdev->dev;
158         dev->irq = irq;
159         platform_set_drvdata(pdev, dev);
160 
161         /* fast mode by default because of legacy reasons */
162         clk_freq = 400000;
163 
164         if (has_acpi_companion(&pdev->dev)) {
165                 dw_i2c_acpi_configure(pdev);
166         } else if (pdev->dev.of_node) {
167                 of_property_read_u32(pdev->dev.of_node,
168                                         "i2c-sda-hold-time-ns", &ht);
169 
170                 of_property_read_u32(pdev->dev.of_node,
171                                      "i2c-sda-falling-time-ns",
172                                      &dev->sda_falling_time);
173                 of_property_read_u32(pdev->dev.of_node,
174                                      "i2c-scl-falling-time-ns",
175                                      &dev->scl_falling_time);
176 
177                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
178                                      &clk_freq);
179 
180                 /* Only standard mode at 100kHz and fast mode at 400kHz
181                  * are supported.
182                  */
183                 if (clk_freq != 100000 && clk_freq != 400000) {
184                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
185                         return -EINVAL;
186                 }
187         } else {
188                 pdata = dev_get_platdata(&pdev->dev);
189                 if (pdata)
190                         clk_freq = pdata->i2c_scl_freq;
191         }
192 
193         r = i2c_dw_eval_lock_support(dev);
194         if (r)
195                 return r;
196 
197         dev->functionality =
198                 I2C_FUNC_I2C |
199                 I2C_FUNC_10BIT_ADDR |
200                 I2C_FUNC_SMBUS_BYTE |
201                 I2C_FUNC_SMBUS_BYTE_DATA |
202                 I2C_FUNC_SMBUS_WORD_DATA |
203                 I2C_FUNC_SMBUS_I2C_BLOCK;
204         if (clk_freq == 100000)
205                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
206                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
207         else
208                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
209                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
210 
211         dev->clk = devm_clk_get(&pdev->dev, NULL);
212         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
213         if (IS_ERR(dev->clk))
214                 return PTR_ERR(dev->clk);
215         clk_prepare_enable(dev->clk);
216 
217         if (!dev->sda_hold_time && ht) {
218                 u32 ic_clk = dev->get_clk_rate_khz(dev);
219 
220                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
221                                              1000000);
222         }
223 
224         if (!dev->tx_fifo_depth) {
225                 u32 param1 = i2c_dw_read_comp_param(dev);
226 
227                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
228                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
229                 dev->adapter.nr = pdev->id;
230         }
231 
232         adap = &dev->adapter;
233         adap->owner = THIS_MODULE;
234         adap->class = I2C_CLASS_DEPRECATED;
235         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
236         adap->dev.of_node = pdev->dev.of_node;
237 
238         if (dev->pm_runtime_disabled) {
239                 pm_runtime_forbid(&pdev->dev);
240         } else {
241                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
242                 pm_runtime_use_autosuspend(&pdev->dev);
243                 pm_runtime_set_active(&pdev->dev);
244                 pm_runtime_enable(&pdev->dev);
245         }
246 
247         r = i2c_dw_probe(dev);
248         if (r && !dev->pm_runtime_disabled)
249                 pm_runtime_disable(&pdev->dev);
250 
251         return r;
252 }
253 
254 static int dw_i2c_plat_remove(struct platform_device *pdev)
255 {
256         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
257 
258         pm_runtime_get_sync(&pdev->dev);
259 
260         i2c_del_adapter(&dev->adapter);
261 
262         i2c_dw_disable(dev);
263 
264         pm_runtime_dont_use_autosuspend(&pdev->dev);
265         pm_runtime_put_sync(&pdev->dev);
266         if (!dev->pm_runtime_disabled)
267                 pm_runtime_disable(&pdev->dev);
268 
269         return 0;
270 }
271 
272 #ifdef CONFIG_OF
273 static const struct of_device_id dw_i2c_of_match[] = {
274         { .compatible = "snps,designware-i2c", },
275         {},
276 };
277 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
278 #endif
279 
280 #ifdef CONFIG_PM_SLEEP
281 static int dw_i2c_plat_prepare(struct device *dev)
282 {
283         return pm_runtime_suspended(dev);
284 }
285 
286 static void dw_i2c_plat_complete(struct device *dev)
287 {
288         if (dev->power.direct_complete)
289                 pm_request_resume(dev);
290 }
291 #else
292 #define dw_i2c_plat_prepare     NULL
293 #define dw_i2c_plat_complete    NULL
294 #endif
295 
296 #ifdef CONFIG_PM
297 static int dw_i2c_plat_suspend(struct device *dev)
298 {
299         struct platform_device *pdev = to_platform_device(dev);
300         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
301 
302         i2c_dw_disable(i_dev);
303         clk_disable_unprepare(i_dev->clk);
304 
305         return 0;
306 }
307 
308 static int dw_i2c_plat_resume(struct device *dev)
309 {
310         struct platform_device *pdev = to_platform_device(dev);
311         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
312 
313         clk_prepare_enable(i_dev->clk);
314 
315         if (!i_dev->pm_runtime_disabled)
316                 i2c_dw_init(i_dev);
317 
318         return 0;
319 }
320 
321 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
322         .prepare = dw_i2c_plat_prepare,
323         .complete = dw_i2c_plat_complete,
324         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
325         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
326 };
327 
328 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
329 #else
330 #define DW_I2C_DEV_PMOPS NULL
331 #endif
332 
333 /* work with hotplug and coldplug */
334 MODULE_ALIAS("platform:i2c_designware");
335 
336 static struct platform_driver dw_i2c_driver = {
337         .probe = dw_i2c_plat_probe,
338         .remove = dw_i2c_plat_remove,
339         .driver         = {
340                 .name   = "i2c_designware",
341                 .of_match_table = of_match_ptr(dw_i2c_of_match),
342                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
343                 .pm     = DW_I2C_DEV_PMOPS,
344         },
345 };
346 
347 static int __init dw_i2c_init_driver(void)
348 {
349         return platform_driver_register(&dw_i2c_driver);
350 }
351 subsys_initcall(dw_i2c_init_driver);
352 
353 static void __exit dw_i2c_exit_driver(void)
354 {
355         platform_driver_unregister(&dw_i2c_driver);
356 }
357 module_exit(dw_i2c_exit_driver);
358 
359 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
360 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
361 MODULE_LICENSE("GPL");
362 

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