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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 int dw_i2c_plat_probe(struct platform_device *pdev)
154 {
155         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
156         struct dw_i2c_dev *dev;
157         struct i2c_adapter *adap;
158         struct resource *mem;
159         int irq, r;
160         u32 acpi_speed, ht = 0;
161 
162         irq = platform_get_irq(pdev, 0);
163         if (irq < 0)
164                 return irq;
165 
166         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
167         if (!dev)
168                 return -ENOMEM;
169 
170         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
171         dev->base = devm_ioremap_resource(&pdev->dev, mem);
172         if (IS_ERR(dev->base))
173                 return PTR_ERR(dev->base);
174 
175         dev->dev = &pdev->dev;
176         dev->irq = irq;
177         platform_set_drvdata(pdev, dev);
178 
179         /* fast mode by default because of legacy reasons */
180         dev->clk_freq = 400000;
181 
182         if (pdata) {
183                 dev->clk_freq = pdata->i2c_scl_freq;
184         } else {
185                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
186                                          &ht);
187                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
188                                          &dev->sda_falling_time);
189                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
190                                          &dev->scl_falling_time);
191                 device_property_read_u32(&pdev->dev, "clock-frequency",
192                                          &dev->clk_freq);
193         }
194 
195         acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
196         if (acpi_speed)
197                 dev->clk_freq = acpi_speed;
198 
199         if (has_acpi_companion(&pdev->dev))
200                 dw_i2c_acpi_configure(pdev);
201 
202         /*
203          * Only standard mode at 100kHz, fast mode at 400kHz,
204          * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
205          */
206         if (dev->clk_freq != 100000 && dev->clk_freq != 400000
207             && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
208                 dev_err(&pdev->dev,
209                         "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
210                 return -EINVAL;
211         }
212 
213         r = i2c_dw_eval_lock_support(dev);
214         if (r)
215                 return r;
216 
217         dev->functionality =
218                 I2C_FUNC_I2C |
219                 I2C_FUNC_10BIT_ADDR |
220                 I2C_FUNC_SMBUS_BYTE |
221                 I2C_FUNC_SMBUS_BYTE_DATA |
222                 I2C_FUNC_SMBUS_WORD_DATA |
223                 I2C_FUNC_SMBUS_I2C_BLOCK;
224 
225         dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
226                           DW_IC_CON_RESTART_EN;
227 
228         switch (dev->clk_freq) {
229         case 100000:
230                 dev->master_cfg |= DW_IC_CON_SPEED_STD;
231                 break;
232         case 3400000:
233                 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
234                 break;
235         default:
236                 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
237         }
238 
239         dev->clk = devm_clk_get(&pdev->dev, NULL);
240         if (!i2c_dw_plat_prepare_clk(dev, true)) {
241                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
242 
243                 if (!dev->sda_hold_time && ht)
244                         dev->sda_hold_time = div_u64(
245                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
246                                 1000000);
247         }
248 
249         if (!dev->tx_fifo_depth) {
250                 u32 param1 = i2c_dw_read_comp_param(dev);
251 
252                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
253                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
254                 dev->adapter.nr = pdev->id;
255         }
256 
257         adap = &dev->adapter;
258         adap->owner = THIS_MODULE;
259         adap->class = I2C_CLASS_DEPRECATED;
260         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
261         adap->dev.of_node = pdev->dev.of_node;
262 
263         if (dev->pm_runtime_disabled) {
264                 pm_runtime_forbid(&pdev->dev);
265         } else {
266                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
267                 pm_runtime_use_autosuspend(&pdev->dev);
268                 pm_runtime_set_active(&pdev->dev);
269                 pm_runtime_enable(&pdev->dev);
270         }
271 
272         r = i2c_dw_probe(dev);
273         if (r && !dev->pm_runtime_disabled)
274                 pm_runtime_disable(&pdev->dev);
275 
276         return r;
277 }
278 
279 static int dw_i2c_plat_remove(struct platform_device *pdev)
280 {
281         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
282 
283         pm_runtime_get_sync(&pdev->dev);
284 
285         i2c_del_adapter(&dev->adapter);
286 
287         i2c_dw_disable(dev);
288 
289         pm_runtime_dont_use_autosuspend(&pdev->dev);
290         pm_runtime_put_sync(&pdev->dev);
291         if (!dev->pm_runtime_disabled)
292                 pm_runtime_disable(&pdev->dev);
293 
294         return 0;
295 }
296 
297 #ifdef CONFIG_OF
298 static const struct of_device_id dw_i2c_of_match[] = {
299         { .compatible = "snps,designware-i2c", },
300         {},
301 };
302 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
303 #endif
304 
305 #ifdef CONFIG_PM_SLEEP
306 static int dw_i2c_plat_prepare(struct device *dev)
307 {
308         return pm_runtime_suspended(dev);
309 }
310 
311 static void dw_i2c_plat_complete(struct device *dev)
312 {
313         if (dev->power.direct_complete)
314                 pm_request_resume(dev);
315 }
316 #else
317 #define dw_i2c_plat_prepare     NULL
318 #define dw_i2c_plat_complete    NULL
319 #endif
320 
321 #ifdef CONFIG_PM
322 static int dw_i2c_plat_suspend(struct device *dev)
323 {
324         struct platform_device *pdev = to_platform_device(dev);
325         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
326 
327         i2c_dw_disable(i_dev);
328         i2c_dw_plat_prepare_clk(i_dev, false);
329 
330         return 0;
331 }
332 
333 static int dw_i2c_plat_resume(struct device *dev)
334 {
335         struct platform_device *pdev = to_platform_device(dev);
336         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
337 
338         i2c_dw_plat_prepare_clk(i_dev, true);
339 
340         if (!i_dev->pm_runtime_disabled)
341                 i2c_dw_init(i_dev);
342 
343         return 0;
344 }
345 
346 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
347         .prepare = dw_i2c_plat_prepare,
348         .complete = dw_i2c_plat_complete,
349         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
350         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
351 };
352 
353 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
354 #else
355 #define DW_I2C_DEV_PMOPS NULL
356 #endif
357 
358 /* work with hotplug and coldplug */
359 MODULE_ALIAS("platform:i2c_designware");
360 
361 static struct platform_driver dw_i2c_driver = {
362         .probe = dw_i2c_plat_probe,
363         .remove = dw_i2c_plat_remove,
364         .driver         = {
365                 .name   = "i2c_designware",
366                 .of_match_table = of_match_ptr(dw_i2c_of_match),
367                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
368                 .pm     = DW_I2C_DEV_PMOPS,
369         },
370 };
371 
372 static int __init dw_i2c_init_driver(void)
373 {
374         return platform_driver_register(&dw_i2c_driver);
375 }
376 subsys_initcall(dw_i2c_init_driver);
377 
378 static void __exit dw_i2c_exit_driver(void)
379 {
380         platform_driver_unregister(&dw_i2c_driver);
381 }
382 module_exit(dw_i2c_exit_driver);
383 
384 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
385 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
386 MODULE_LICENSE("GPL");
387 

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