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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/property.h>
 40 #include <linux/io.h>
 41 #include <linux/slab.h>
 42 #include <linux/acpi.h>
 43 #include <linux/platform_data/i2c-designware.h>
 44 #include "i2c-designware-core.h"
 45 
 46 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 47 {
 48         return clk_get_rate(dev->clk)/1000;
 49 }
 50 
 51 #ifdef CONFIG_ACPI
 52 /*
 53  * The HCNT/LCNT information coming from ACPI should be the most accurate
 54  * for given platform. However, some systems get it wrong. On such systems
 55  * we get better results by calculating those based on the input clock.
 56  */
 57 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
 58         {
 59                 .ident = "Dell Inspiron 7348",
 60                 .matches = {
 61                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 62                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
 63                 },
 64         },
 65         { }
 66 };
 67 
 68 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 69                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
 70 {
 71         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 72         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 73         union acpi_object *obj;
 74 
 75         if (dmi_check_system(dw_i2c_no_acpi_params))
 76                 return;
 77 
 78         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
 79                 return;
 80 
 81         obj = (union acpi_object *)buf.pointer;
 82         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
 83                 const union acpi_object *objs = obj->package.elements;
 84 
 85                 *hcnt = (u16)objs[0].integer.value;
 86                 *lcnt = (u16)objs[1].integer.value;
 87                 if (sda_hold)
 88                         *sda_hold = (u32)objs[2].integer.value;
 89         }
 90 
 91         kfree(buf.pointer);
 92 }
 93 
 94 static int dw_i2c_acpi_configure(struct platform_device *pdev)
 95 {
 96         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 97         const struct acpi_device_id *id;
 98 
 99         dev->adapter.nr = -1;
100         dev->tx_fifo_depth = 32;
101         dev->rx_fifo_depth = 32;
102 
103         /*
104          * Try to get SDA hold time and *CNT values from an ACPI method if
105          * it exists for both supported speed modes.
106          */
107         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
108         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
109                            &dev->sda_hold_time);
110         dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, NULL);
111         dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, NULL);
112 
113         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
114         if (id && id->driver_data)
115                 dev->accessor_flags |= (u32)id->driver_data;
116 
117         return 0;
118 }
119 
120 static const struct acpi_device_id dw_i2c_acpi_match[] = {
121         { "INT33C2", 0 },
122         { "INT33C3", 0 },
123         { "INT3432", 0 },
124         { "INT3433", 0 },
125         { "80860F41", 0 },
126         { "808622C1", 0 },
127         { "AMD0010", ACCESS_INTR_MASK },
128         { "AMDI0010", ACCESS_INTR_MASK },
129         { "AMDI0510", 0 },
130         { "APMC0D0F", 0 },
131         { }
132 };
133 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
134 #else
135 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
136 {
137         return -ENODEV;
138 }
139 #endif
140 
141 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
142 {
143         if (IS_ERR(i_dev->clk))
144                 return PTR_ERR(i_dev->clk);
145 
146         if (prepare)
147                 return clk_prepare_enable(i_dev->clk);
148 
149         clk_disable_unprepare(i_dev->clk);
150         return 0;
151 }
152 
153 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
154 {
155         u32 param, tx_fifo_depth, rx_fifo_depth;
156 
157         /*
158          * Try to detect the FIFO depth if not set by interface driver,
159          * the depth could be from 2 to 256 from HW spec.
160          */
161         param = i2c_dw_read_comp_param(dev);
162         tx_fifo_depth = ((param >> 16) & 0xff) + 1;
163         rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
164         if (!dev->tx_fifo_depth) {
165                 dev->tx_fifo_depth = tx_fifo_depth;
166                 dev->rx_fifo_depth = rx_fifo_depth;
167                 dev->adapter.nr = id;
168         } else if (tx_fifo_depth >= 2) {
169                 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
170                                 tx_fifo_depth);
171                 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
172                                 rx_fifo_depth);
173         }
174 }
175 
176 static int dw_i2c_plat_probe(struct platform_device *pdev)
177 {
178         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
179         struct dw_i2c_dev *dev;
180         struct i2c_adapter *adap;
181         struct resource *mem;
182         int irq, r;
183         u32 acpi_speed, ht = 0;
184 
185         irq = platform_get_irq(pdev, 0);
186         if (irq < 0)
187                 return irq;
188 
189         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
190         if (!dev)
191                 return -ENOMEM;
192 
193         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
194         dev->base = devm_ioremap_resource(&pdev->dev, mem);
195         if (IS_ERR(dev->base))
196                 return PTR_ERR(dev->base);
197 
198         dev->dev = &pdev->dev;
199         dev->irq = irq;
200         platform_set_drvdata(pdev, dev);
201 
202         if (pdata) {
203                 dev->clk_freq = pdata->i2c_scl_freq;
204         } else {
205                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
206                                          &ht);
207                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
208                                          &dev->sda_falling_time);
209                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
210                                          &dev->scl_falling_time);
211                 device_property_read_u32(&pdev->dev, "clock-frequency",
212                                          &dev->clk_freq);
213         }
214 
215         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
216         /*
217          * Find bus speed from the "clock-frequency" device property, ACPI
218          * or by using fast mode if neither is set.
219          */
220         if (acpi_speed && dev->clk_freq)
221                 dev->clk_freq = min(dev->clk_freq, acpi_speed);
222         else if (acpi_speed || dev->clk_freq)
223                 dev->clk_freq = max(dev->clk_freq, acpi_speed);
224         else
225                 dev->clk_freq = 400000;
226 
227         if (has_acpi_companion(&pdev->dev))
228                 dw_i2c_acpi_configure(pdev);
229 
230         /*
231          * Only standard mode at 100kHz, fast mode at 400kHz,
232          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
233          */
234         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
235             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
236                 dev_err(&pdev->dev,
237                         "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
238                 return -EINVAL;
239         }
240 
241         r = i2c_dw_eval_lock_support(dev);
242         if (r)
243                 return r;
244 
245         dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
246 
247         dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
248                           DW_IC_CON_RESTART_EN;
249 
250         switch (dev->clk_freq) {
251         case 100000:
252                 dev->master_cfg |= DW_IC_CON_SPEED_STD;
253                 break;
254         case 3400000:
255                 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
256                 break;
257         default:
258                 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
259         }
260 
261         dev->clk = devm_clk_get(&pdev->dev, NULL);
262         if (!i2c_dw_plat_prepare_clk(dev, true)) {
263                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
264 
265                 if (!dev->sda_hold_time && ht)
266                         dev->sda_hold_time = div_u64(
267                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
268                                 1000000);
269         }
270 
271         dw_i2c_set_fifo_size(dev, pdev->id);
272 
273         adap = &dev->adapter;
274         adap->owner = THIS_MODULE;
275         adap->class = I2C_CLASS_DEPRECATED;
276         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
277         adap->dev.of_node = pdev->dev.of_node;
278 
279         if (dev->pm_runtime_disabled) {
280                 pm_runtime_forbid(&pdev->dev);
281         } else {
282                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
283                 pm_runtime_use_autosuspend(&pdev->dev);
284                 pm_runtime_set_active(&pdev->dev);
285                 pm_runtime_enable(&pdev->dev);
286         }
287 
288         r = i2c_dw_probe(dev);
289         if (r && !dev->pm_runtime_disabled)
290                 pm_runtime_disable(&pdev->dev);
291 
292         return r;
293 }
294 
295 static int dw_i2c_plat_remove(struct platform_device *pdev)
296 {
297         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
298 
299         pm_runtime_get_sync(&pdev->dev);
300 
301         i2c_del_adapter(&dev->adapter);
302 
303         i2c_dw_disable(dev);
304 
305         pm_runtime_dont_use_autosuspend(&pdev->dev);
306         pm_runtime_put_sync(&pdev->dev);
307         if (!dev->pm_runtime_disabled)
308                 pm_runtime_disable(&pdev->dev);
309 
310         return 0;
311 }
312 
313 #ifdef CONFIG_OF
314 static const struct of_device_id dw_i2c_of_match[] = {
315         { .compatible = "snps,designware-i2c", },
316         {},
317 };
318 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
319 #endif
320 
321 #ifdef CONFIG_PM_SLEEP
322 static int dw_i2c_plat_prepare(struct device *dev)
323 {
324         return pm_runtime_suspended(dev);
325 }
326 
327 static void dw_i2c_plat_complete(struct device *dev)
328 {
329         if (dev->power.direct_complete)
330                 pm_request_resume(dev);
331 }
332 #else
333 #define dw_i2c_plat_prepare     NULL
334 #define dw_i2c_plat_complete    NULL
335 #endif
336 
337 #ifdef CONFIG_PM
338 static int dw_i2c_plat_suspend(struct device *dev)
339 {
340         struct platform_device *pdev = to_platform_device(dev);
341         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
342 
343         i2c_dw_disable(i_dev);
344         i2c_dw_plat_prepare_clk(i_dev, false);
345 
346         return 0;
347 }
348 
349 static int dw_i2c_plat_resume(struct device *dev)
350 {
351         struct platform_device *pdev = to_platform_device(dev);
352         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
353 
354         i2c_dw_plat_prepare_clk(i_dev, true);
355 
356         if (!i_dev->pm_runtime_disabled)
357                 i2c_dw_init(i_dev);
358 
359         return 0;
360 }
361 
362 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
363         .prepare = dw_i2c_plat_prepare,
364         .complete = dw_i2c_plat_complete,
365         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
366         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
367 };
368 
369 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
370 #else
371 #define DW_I2C_DEV_PMOPS NULL
372 #endif
373 
374 /* work with hotplug and coldplug */
375 MODULE_ALIAS("platform:i2c_designware");
376 
377 static struct platform_driver dw_i2c_driver = {
378         .probe = dw_i2c_plat_probe,
379         .remove = dw_i2c_plat_remove,
380         .driver         = {
381                 .name   = "i2c_designware",
382                 .of_match_table = of_match_ptr(dw_i2c_of_match),
383                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
384                 .pm     = DW_I2C_DEV_PMOPS,
385         },
386 };
387 
388 static int __init dw_i2c_init_driver(void)
389 {
390         return platform_driver_register(&dw_i2c_driver);
391 }
392 subsys_initcall(dw_i2c_init_driver);
393 
394 static void __exit dw_i2c_exit_driver(void)
395 {
396         platform_driver_unregister(&dw_i2c_driver);
397 }
398 module_exit(dw_i2c_exit_driver);
399 
400 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
401 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
402 MODULE_LICENSE("GPL");
403 

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