Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

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  * You should have received a copy of the GNU General Public License
 23  * along with this program; if not, write to the Free Software
 24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 25  * ----------------------------------------------------------------------------
 26  *
 27  */
 28 #include <linux/kernel.h>
 29 #include <linux/module.h>
 30 #include <linux/delay.h>
 31 #include <linux/i2c.h>
 32 #include <linux/clk.h>
 33 #include <linux/errno.h>
 34 #include <linux/sched.h>
 35 #include <linux/err.h>
 36 #include <linux/interrupt.h>
 37 #include <linux/of.h>
 38 #include <linux/platform_device.h>
 39 #include <linux/pm.h>
 40 #include <linux/pm_runtime.h>
 41 #include <linux/io.h>
 42 #include <linux/slab.h>
 43 #include <linux/acpi.h>
 44 #include "i2c-designware-core.h"
 45 
 46 static struct i2c_algorithm i2c_dw_algo = {
 47         .master_xfer    = i2c_dw_xfer,
 48         .functionality  = i2c_dw_func,
 49 };
 50 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 51 {
 52         return clk_get_rate(dev->clk)/1000;
 53 }
 54 
 55 #ifdef CONFIG_ACPI
 56 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 57                                u16 *hcnt, u16 *lcnt, u32 *sda_hold)
 58 {
 59         struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
 60         acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 61         union acpi_object *obj;
 62 
 63         if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
 64                 return;
 65 
 66         obj = (union acpi_object *)buf.pointer;
 67         if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
 68                 const union acpi_object *objs = obj->package.elements;
 69 
 70                 *hcnt = (u16)objs[0].integer.value;
 71                 *lcnt = (u16)objs[1].integer.value;
 72                 if (sda_hold)
 73                         *sda_hold = (u32)objs[2].integer.value;
 74         }
 75 
 76         kfree(buf.pointer);
 77 }
 78 
 79 static int dw_i2c_acpi_configure(struct platform_device *pdev)
 80 {
 81         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
 82         bool fs_mode = dev->master_cfg & DW_IC_CON_SPEED_FAST;
 83 
 84         if (!ACPI_HANDLE(&pdev->dev))
 85                 return -ENODEV;
 86 
 87         dev->adapter.nr = -1;
 88         dev->tx_fifo_depth = 32;
 89         dev->rx_fifo_depth = 32;
 90 
 91         /*
 92          * Try to get SDA hold time and *CNT values from an ACPI method if
 93          * it exists for both supported speed modes.
 94          */
 95         dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt,
 96                            fs_mode ? NULL : &dev->sda_hold_time);
 97         dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
 98                            fs_mode ? &dev->sda_hold_time : NULL);
 99 
100         return 0;
101 }
102 
103 static const struct acpi_device_id dw_i2c_acpi_match[] = {
104         { "INT33C2", 0 },
105         { "INT33C3", 0 },
106         { "INT3432", 0 },
107         { "INT3433", 0 },
108         { "80860F41", 0 },
109         { "808622C1", 0 },
110         { }
111 };
112 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
113 #else
114 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
115 {
116         return -ENODEV;
117 }
118 #endif
119 
120 static int dw_i2c_probe(struct platform_device *pdev)
121 {
122         struct dw_i2c_dev *dev;
123         struct i2c_adapter *adap;
124         struct resource *mem;
125         int irq, r;
126 
127         irq = platform_get_irq(pdev, 0);
128         if (irq < 0) {
129                 dev_err(&pdev->dev, "no irq resource?\n");
130                 return irq; /* -ENXIO */
131         }
132 
133         dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
134         if (!dev)
135                 return -ENOMEM;
136 
137         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
138         dev->base = devm_ioremap_resource(&pdev->dev, mem);
139         if (IS_ERR(dev->base))
140                 return PTR_ERR(dev->base);
141 
142         init_completion(&dev->cmd_complete);
143         mutex_init(&dev->lock);
144         dev->dev = &pdev->dev;
145         dev->irq = irq;
146         platform_set_drvdata(pdev, dev);
147 
148         dev->clk = devm_clk_get(&pdev->dev, NULL);
149         dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
150 
151         if (IS_ERR(dev->clk))
152                 return PTR_ERR(dev->clk);
153         clk_prepare_enable(dev->clk);
154 
155         if (pdev->dev.of_node) {
156                 u32 ht = 0;
157                 u32 ic_clk = dev->get_clk_rate_khz(dev);
158 
159                 of_property_read_u32(pdev->dev.of_node,
160                                         "i2c-sda-hold-time-ns", &ht);
161                 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
162                                              1000000);
163 
164                 of_property_read_u32(pdev->dev.of_node,
165                                      "i2c-sda-falling-time-ns",
166                                      &dev->sda_falling_time);
167                 of_property_read_u32(pdev->dev.of_node,
168                                      "i2c-scl-falling-time-ns",
169                                      &dev->scl_falling_time);
170         }
171 
172         dev->functionality =
173                 I2C_FUNC_I2C |
174                 I2C_FUNC_10BIT_ADDR |
175                 I2C_FUNC_SMBUS_BYTE |
176                 I2C_FUNC_SMBUS_BYTE_DATA |
177                 I2C_FUNC_SMBUS_WORD_DATA |
178                 I2C_FUNC_SMBUS_I2C_BLOCK;
179         dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
180                 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
181 
182         /* Try first if we can configure the device from ACPI */
183         r = dw_i2c_acpi_configure(pdev);
184         if (r) {
185                 u32 param1 = i2c_dw_read_comp_param(dev);
186 
187                 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
188                 dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
189                 dev->adapter.nr = pdev->id;
190         }
191         r = i2c_dw_init(dev);
192         if (r)
193                 return r;
194 
195         i2c_dw_disable_int(dev);
196         r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
197                         pdev->name, dev);
198         if (r) {
199                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
200                 return r;
201         }
202 
203         adap = &dev->adapter;
204         i2c_set_adapdata(adap, dev);
205         adap->owner = THIS_MODULE;
206         adap->class = I2C_CLASS_DEPRECATED;
207         strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
208                         sizeof(adap->name));
209         adap->algo = &i2c_dw_algo;
210         adap->dev.parent = &pdev->dev;
211         adap->dev.of_node = pdev->dev.of_node;
212 
213         r = i2c_add_numbered_adapter(adap);
214         if (r) {
215                 dev_err(&pdev->dev, "failure adding adapter\n");
216                 return r;
217         }
218 
219         pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
220         pm_runtime_use_autosuspend(&pdev->dev);
221         pm_runtime_set_active(&pdev->dev);
222         pm_runtime_enable(&pdev->dev);
223 
224         return 0;
225 }
226 
227 static int dw_i2c_remove(struct platform_device *pdev)
228 {
229         struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
230 
231         pm_runtime_get_sync(&pdev->dev);
232 
233         i2c_del_adapter(&dev->adapter);
234 
235         i2c_dw_disable(dev);
236 
237         pm_runtime_put(&pdev->dev);
238         pm_runtime_disable(&pdev->dev);
239 
240         return 0;
241 }
242 
243 #ifdef CONFIG_OF
244 static const struct of_device_id dw_i2c_of_match[] = {
245         { .compatible = "snps,designware-i2c", },
246         {},
247 };
248 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
249 #endif
250 
251 #ifdef CONFIG_PM
252 static int dw_i2c_suspend(struct device *dev)
253 {
254         struct platform_device *pdev = to_platform_device(dev);
255         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
256 
257         i2c_dw_disable(i_dev);
258         clk_disable_unprepare(i_dev->clk);
259 
260         return 0;
261 }
262 
263 static int dw_i2c_resume(struct device *dev)
264 {
265         struct platform_device *pdev = to_platform_device(dev);
266         struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
267 
268         clk_prepare_enable(i_dev->clk);
269         i2c_dw_init(i_dev);
270 
271         return 0;
272 }
273 #endif
274 
275 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
276                             dw_i2c_resume, NULL);
277 
278 /* work with hotplug and coldplug */
279 MODULE_ALIAS("platform:i2c_designware");
280 
281 static struct platform_driver dw_i2c_driver = {
282         .probe = dw_i2c_probe,
283         .remove = dw_i2c_remove,
284         .driver         = {
285                 .name   = "i2c_designware",
286                 .owner  = THIS_MODULE,
287                 .of_match_table = of_match_ptr(dw_i2c_of_match),
288                 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
289                 .pm     = &dw_i2c_dev_pm_ops,
290         },
291 };
292 
293 static int __init dw_i2c_init_driver(void)
294 {
295         return platform_driver_register(&dw_i2c_driver);
296 }
297 subsys_initcall(dw_i2c_init_driver);
298 
299 static void __exit dw_i2c_exit_driver(void)
300 {
301         platform_driver_unregister(&dw_i2c_driver);
302 }
303 module_exit(dw_i2c_exit_driver);
304 
305 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
306 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
307 MODULE_LICENSE("GPL");
308 

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