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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 
111         id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
112         if (id && id->driver_data)
113                 dev->accessor_flags |= (u32)id->driver_data;
114 
115         return 0;
116 }
117 
118 static const struct acpi_device_id dw_i2c_acpi_match[] = {
119         { "INT33C2", 0 },
120         { "INT33C3", 0 },
121         { "INT3432", 0 },
122         { "INT3433", 0 },
123         { "80860F41", 0 },
124         { "808622C1", 0 },
125         { "AMD0010", ACCESS_INTR_MASK },
126         { "AMDI0010", ACCESS_INTR_MASK },
127         { "AMDI0510", 0 },
128         { "APMC0D0F", 0 },
129         { }
130 };
131 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
132 #else
133 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
134 {
135         return -ENODEV;
136 }
137 #endif
138 
139 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
140 {
141         if (IS_ERR(i_dev->clk))
142                 return PTR_ERR(i_dev->clk);
143 
144         if (prepare)
145                 return clk_prepare_enable(i_dev->clk);
146 
147         clk_disable_unprepare(i_dev->clk);
148         return 0;
149 }
150 
151 static int dw_i2c_plat_probe(struct platform_device *pdev)
152 {
153         struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
154         struct dw_i2c_dev *dev;
155         struct i2c_adapter *adap;
156         struct resource *mem;
157         int irq, r;
158         u32 clk_freq, ht = 0;
159 
160         irq = platform_get_irq(pdev, 0);
161         if (irq < 0)
162                 return irq;
163 
164         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
165         if (!dev)
166                 return -ENOMEM;
167 
168         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
169         dev->base = devm_ioremap_resource(&pdev->dev, mem);
170         if (IS_ERR(dev->base))
171                 return PTR_ERR(dev->base);
172 
173         dev->dev = &pdev->dev;
174         dev->irq = irq;
175         platform_set_drvdata(pdev, dev);
176 
177         /* fast mode by default because of legacy reasons */
178         clk_freq = 400000;
179 
180         if (pdata) {
181                 clk_freq = pdata->i2c_scl_freq;
182         } else {
183                 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
184                                          &ht);
185                 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
186                                          &dev->sda_falling_time);
187                 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
188                                          &dev->scl_falling_time);
189                 device_property_read_u32(&pdev->dev, "clock-frequency",
190                                          &clk_freq);
191         }
192 
193         if (has_acpi_companion(&pdev->dev))
194                 dw_i2c_acpi_configure(pdev);
195 
196         /*
197          * Only standard mode at 100kHz and fast mode at 400kHz are supported.
198          */
199         if (clk_freq != 100000 && clk_freq != 400000) {
200                 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
201                 return -EINVAL;
202         }
203 
204         r = i2c_dw_eval_lock_support(dev);
205         if (r)
206                 return r;
207 
208         dev->functionality =
209                 I2C_FUNC_I2C |
210                 I2C_FUNC_10BIT_ADDR |
211                 I2C_FUNC_SMBUS_BYTE |
212                 I2C_FUNC_SMBUS_BYTE_DATA |
213                 I2C_FUNC_SMBUS_WORD_DATA |
214                 I2C_FUNC_SMBUS_I2C_BLOCK;
215         if (clk_freq == 100000)
216                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
217                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
218         else
219                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
220                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
221 
222         dev->clk = devm_clk_get(&pdev->dev, NULL);
223         if (!i2c_dw_plat_prepare_clk(dev, true)) {
224                 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
225 
226                 if (!dev->sda_hold_time && ht)
227                         dev->sda_hold_time = div_u64(
228                                 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
229                                 1000000);
230         }
231 
232         if (!dev->tx_fifo_depth) {
233                 u32 param1 = i2c_dw_read_comp_param(dev);
234 
235                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
236                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
237                 dev->adapter.nr = pdev->id;
238         }
239 
240         adap = &dev->adapter;
241         adap->owner = THIS_MODULE;
242         adap->class = I2C_CLASS_DEPRECATED;
243         ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
244         adap->dev.of_node = pdev->dev.of_node;
245 
246         if (dev->pm_runtime_disabled) {
247                 pm_runtime_forbid(&pdev->dev);
248         } else {
249                 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
250                 pm_runtime_use_autosuspend(&pdev->dev);
251                 pm_runtime_set_active(&pdev->dev);
252                 pm_runtime_enable(&pdev->dev);
253         }
254 
255         r = i2c_dw_probe(dev);
256         if (r && !dev->pm_runtime_disabled)
257                 pm_runtime_disable(&pdev->dev);
258 
259         return r;
260 }
261 
262 static int dw_i2c_plat_remove(struct platform_device *pdev)
263 {
264         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
265 
266         pm_runtime_get_sync(&pdev->dev);
267 
268         i2c_del_adapter(&dev->adapter);
269 
270         i2c_dw_disable(dev);
271 
272         pm_runtime_dont_use_autosuspend(&pdev->dev);
273         pm_runtime_put_sync(&pdev->dev);
274         if (!dev->pm_runtime_disabled)
275                 pm_runtime_disable(&pdev->dev);
276 
277         return 0;
278 }
279 
280 #ifdef CONFIG_OF
281 static const struct of_device_id dw_i2c_of_match[] = {
282         { .compatible = "snps,designware-i2c", },
283         {},
284 };
285 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
286 #endif
287 
288 #ifdef CONFIG_PM_SLEEP
289 static int dw_i2c_plat_prepare(struct device *dev)
290 {
291         return pm_runtime_suspended(dev);
292 }
293 
294 static void dw_i2c_plat_complete(struct device *dev)
295 {
296         if (dev->power.direct_complete)
297                 pm_request_resume(dev);
298 }
299 #else
300 #define dw_i2c_plat_prepare     NULL
301 #define dw_i2c_plat_complete    NULL
302 #endif
303 
304 #ifdef CONFIG_PM
305 static int dw_i2c_plat_suspend(struct device *dev)
306 {
307         struct platform_device *pdev = to_platform_device(dev);
308         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
309 
310         i2c_dw_disable(i_dev);
311         i2c_dw_plat_prepare_clk(i_dev, false);
312 
313         return 0;
314 }
315 
316 static int dw_i2c_plat_resume(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_plat_prepare_clk(i_dev, true);
322 
323         if (!i_dev->pm_runtime_disabled)
324                 i2c_dw_init(i_dev);
325 
326         return 0;
327 }
328 
329 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
330         .prepare = dw_i2c_plat_prepare,
331         .complete = dw_i2c_plat_complete,
332         SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
333         SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
334 };
335 
336 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
337 #else
338 #define DW_I2C_DEV_PMOPS NULL
339 #endif
340 
341 /* work with hotplug and coldplug */
342 MODULE_ALIAS("platform:i2c_designware");
343 
344 static struct platform_driver dw_i2c_driver = {
345         .probe = dw_i2c_plat_probe,
346         .remove = dw_i2c_plat_remove,
347         .driver         = {
348                 .name   = "i2c_designware",
349                 .of_match_table = of_match_ptr(dw_i2c_of_match),
350                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
351                 .pm     = DW_I2C_DEV_PMOPS,
352         },
353 };
354 
355 static int __init dw_i2c_init_driver(void)
356 {
357         return platform_driver_register(&dw_i2c_driver);
358 }
359 subsys_initcall(dw_i2c_init_driver);
360 
361 static void __exit dw_i2c_exit_driver(void)
362 {
363         platform_driver_unregister(&dw_i2c_driver);
364 }
365 module_exit(dw_i2c_exit_driver);
366 
367 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
368 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
369 MODULE_LICENSE("GPL");
370 

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