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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                 dev_err(&pdev->dev, "no irq resource?\n");
148                 return irq; /* -ENXIO */
149         }
150 
151         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
152         if (!dev)
153                 return -ENOMEM;
154 
155         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
156         dev->base = devm_ioremap_resource(&pdev->dev, mem);
157         if (IS_ERR(dev->base))
158                 return PTR_ERR(dev->base);
159 
160         init_completion(&dev->cmd_complete);
161         mutex_init(&dev->lock);
162         dev->dev = &pdev->dev;
163         dev->irq = irq;
164         platform_set_drvdata(pdev, dev);
165 
166         /* fast mode by default because of legacy reasons */
167         clk_freq = 400000;
168 
169         if (ACPI_COMPANION(&pdev->dev)) {
170                 dw_i2c_acpi_configure(pdev);
171         } else if (pdev->dev.of_node) {
172                 of_property_read_u32(pdev->dev.of_node,
173                                         "i2c-sda-hold-time-ns", &ht);
174 
175                 of_property_read_u32(pdev->dev.of_node,
176                                      "i2c-sda-falling-time-ns",
177                                      &dev->sda_falling_time);
178                 of_property_read_u32(pdev->dev.of_node,
179                                      "i2c-scl-falling-time-ns",
180                                      &dev->scl_falling_time);
181 
182                 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
183                                      &clk_freq);
184 
185                 /* Only standard mode at 100kHz and fast mode at 400kHz
186                  * are supported.
187                  */
188                 if (clk_freq != 100000 && clk_freq != 400000) {
189                         dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
190                         return -EINVAL;
191                 }
192         } else {
193                 pdata = dev_get_platdata(&pdev->dev);
194                 if (pdata)
195                         clk_freq = pdata->i2c_scl_freq;
196         }
197 
198         dev->functionality =
199                 I2C_FUNC_I2C |
200                 I2C_FUNC_10BIT_ADDR |
201                 I2C_FUNC_SMBUS_BYTE |
202                 I2C_FUNC_SMBUS_BYTE_DATA |
203                 I2C_FUNC_SMBUS_WORD_DATA |
204                 I2C_FUNC_SMBUS_I2C_BLOCK;
205         if (clk_freq == 100000)
206                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
207                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
208         else
209                 dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
210                         DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
211 
212         dev->clk = devm_clk_get(&pdev->dev, NULL);
213         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
214         if (IS_ERR(dev->clk))
215                 return PTR_ERR(dev->clk);
216         clk_prepare_enable(dev->clk);
217 
218         if (!dev->sda_hold_time && ht) {
219                 u32 ic_clk = dev->get_clk_rate_khz(dev);
220 
221                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
222                                              1000000);
223         }
224 
225         if (!dev->tx_fifo_depth) {
226                 u32 param1 = i2c_dw_read_comp_param(dev);
227 
228                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
229                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
230                 dev->adapter.nr = pdev->id;
231         }
232         r = i2c_dw_init(dev);
233         if (r)
234                 return r;
235 
236         i2c_dw_disable_int(dev);
237         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
238                         pdev->name, dev);
239         if (r) {
240                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
241                 return r;
242         }
243 
244         adap = &dev->adapter;
245         i2c_set_adapdata(adap, dev);
246         adap->owner = THIS_MODULE;
247         adap->class = I2C_CLASS_DEPRECATED;
248         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
249                         sizeof(adap->name));
250         adap->algo = &i2c_dw_algo;
251         adap->dev.parent = &pdev->dev;
252         adap->dev.of_node = pdev->dev.of_node;
253 
254         r = i2c_add_numbered_adapter(adap);
255         if (r) {
256                 dev_err(&pdev->dev, "failure adding adapter\n");
257                 return r;
258         }
259 
260         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
261         pm_runtime_use_autosuspend(&pdev->dev);
262         pm_runtime_set_active(&pdev->dev);
263         pm_runtime_enable(&pdev->dev);
264 
265         return 0;
266 }
267 
268 static int dw_i2c_remove(struct platform_device *pdev)
269 {
270         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
271 
272         pm_runtime_get_sync(&pdev->dev);
273 
274         i2c_del_adapter(&dev->adapter);
275 
276         i2c_dw_disable(dev);
277 
278         pm_runtime_put(&pdev->dev);
279         pm_runtime_disable(&pdev->dev);
280 
281         if (ACPI_COMPANION(&pdev->dev))
282                 dw_i2c_acpi_unconfigure(pdev);
283 
284         return 0;
285 }
286 
287 #ifdef CONFIG_OF
288 static const struct of_device_id dw_i2c_of_match[] = {
289         { .compatible = "snps,designware-i2c", },
290         {},
291 };
292 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
293 #endif
294 
295 #ifdef CONFIG_PM
296 static int dw_i2c_suspend(struct device *dev)
297 {
298         struct platform_device *pdev = to_platform_device(dev);
299         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
300 
301         i2c_dw_disable(i_dev);
302         clk_disable_unprepare(i_dev->clk);
303 
304         return 0;
305 }
306 
307 static int dw_i2c_resume(struct device *dev)
308 {
309         struct platform_device *pdev = to_platform_device(dev);
310         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
311 
312         clk_prepare_enable(i_dev->clk);
313         i2c_dw_init(i_dev);
314 
315         return 0;
316 }
317 #endif
318 
319 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
320                             dw_i2c_resume, NULL);
321 
322 /* work with hotplug and coldplug */
323 MODULE_ALIAS("platform:i2c_designware");
324 
325 static struct platform_driver dw_i2c_driver = {
326         .probe = dw_i2c_probe,
327         .remove = dw_i2c_remove,
328         .driver         = {
329                 .name   = "i2c_designware",
330                 .owner  = THIS_MODULE,
331                 .of_match_table = of_match_ptr(dw_i2c_of_match),
332                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
333                 .pm     = &dw_i2c_dev_pm_ops,
334         },
335 };
336 
337 static int __init dw_i2c_init_driver(void)
338 {
339         return platform_driver_register(&dw_i2c_driver);
340 }
341 subsys_initcall(dw_i2c_init_driver);
342 
343 static void __exit dw_i2c_exit_driver(void)
344 {
345         platform_driver_unregister(&dw_i2c_driver);
346 }
347 module_exit(dw_i2c_exit_driver);
348 
349 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
350 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
351 MODULE_LICENSE("GPL");
352 

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