2 * Synopsys DesignWare I2C adapter driver (master only).
4 * Based on the TI DAVINCI I2C adapter driver.
6 * Copyright (C) 2006 Texas Instruments.
7 * Copyright (C) 2007 MontaVista Software Inc.
8 * Copyright (C) 2009 Provigent Ltd.
10 * ----------------------------------------------------------------------------
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.
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.
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 * ----------------------------------------------------------------------------
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/clk-provider.h>
34 #include <linux/errno.h>
35 #include <linux/sched.h>
36 #include <linux/err.h>
37 #include <linux/interrupt.h>
39 #include <linux/platform_device.h>
41 #include <linux/pm_runtime.h>
43 #include <linux/slab.h>
44 #include <linux/acpi.h>
45 #include <linux/platform_data/i2c-designware.h>
46 #include "i2c-designware-core.h"
48 static struct i2c_algorithm i2c_dw_algo = {
49 .master_xfer = i2c_dw_xfer,
50 .functionality = i2c_dw_func,
52 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
54 return clk_get_rate(dev->clk)/1000;
58 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
59 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
61 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
62 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
63 union acpi_object *obj;
65 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
68 obj = (union acpi_object *)buf.pointer;
69 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
70 const union acpi_object *objs = obj->package.elements;
72 *hcnt = (u16)objs[0].integer.value;
73 *lcnt = (u16)objs[1].integer.value;
75 *sda_hold = (u32)objs[2].integer.value;
81 static int dw_i2c_acpi_configure(struct platform_device *pdev)
83 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
84 const struct acpi_device_id *id;
87 dev->tx_fifo_depth = 32;
88 dev->rx_fifo_depth = 32;
91 * Try to get SDA hold time and *CNT values from an ACPI method if
92 * it exists for both supported speed modes.
94 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
95 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
99 * Provide a way for Designware I2C host controllers that are not
100 * based on Intel LPSS to specify their input clock frequency via
103 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
104 if (id && id->driver_data)
105 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
106 CLK_IS_ROOT, id->driver_data);
111 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
113 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
114 const struct acpi_device_id *id;
116 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
117 if (id && id->driver_data)
118 clk_unregister(dev->clk);
121 static const struct acpi_device_id dw_i2c_acpi_match[] = {
128 { "AMD0010", 133 * 1000 * 1000 },
131 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
133 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
137 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
140 static int dw_i2c_probe(struct platform_device *pdev)
142 struct dw_i2c_dev *dev;
143 struct i2c_adapter *adap;
144 struct resource *mem;
145 struct dw_i2c_platform_data *pdata;
147 u32 clk_freq, ht = 0;
149 irq = platform_get_irq(pdev, 0);
151 dev_err(&pdev->dev, "no irq resource?\n");
152 return irq; /* -ENXIO */
155 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
159 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
160 dev->base = devm_ioremap_resource(&pdev->dev, mem);
161 if (IS_ERR(dev->base))
162 return PTR_ERR(dev->base);
164 init_completion(&dev->cmd_complete);
165 mutex_init(&dev->lock);
166 dev->dev = &pdev->dev;
168 platform_set_drvdata(pdev, dev);
170 /* fast mode by default because of legacy reasons */
173 if (ACPI_COMPANION(&pdev->dev)) {
174 dw_i2c_acpi_configure(pdev);
175 } else if (pdev->dev.of_node) {
176 of_property_read_u32(pdev->dev.of_node,
177 "i2c-sda-hold-time-ns", &ht);
179 of_property_read_u32(pdev->dev.of_node,
180 "i2c-sda-falling-time-ns",
181 &dev->sda_falling_time);
182 of_property_read_u32(pdev->dev.of_node,
183 "i2c-scl-falling-time-ns",
184 &dev->scl_falling_time);
186 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
189 /* Only standard mode at 100kHz and fast mode at 400kHz
192 if (clk_freq != 100000 && clk_freq != 400000) {
193 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
197 pdata = dev_get_platdata(&pdev->dev);
199 clk_freq = pdata->i2c_scl_freq;
204 I2C_FUNC_10BIT_ADDR |
205 I2C_FUNC_SMBUS_BYTE |
206 I2C_FUNC_SMBUS_BYTE_DATA |
207 I2C_FUNC_SMBUS_WORD_DATA |
208 I2C_FUNC_SMBUS_I2C_BLOCK;
209 if (clk_freq == 100000)
210 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
211 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
213 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
214 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
216 dev->clk = devm_clk_get(&pdev->dev, NULL);
217 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
218 if (IS_ERR(dev->clk))
219 return PTR_ERR(dev->clk);
220 clk_prepare_enable(dev->clk);
222 if (!dev->sda_hold_time && ht) {
223 u32 ic_clk = dev->get_clk_rate_khz(dev);
225 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
229 if (!dev->tx_fifo_depth) {
230 u32 param1 = i2c_dw_read_comp_param(dev);
232 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
233 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
234 dev->adapter.nr = pdev->id;
236 r = i2c_dw_init(dev);
240 i2c_dw_disable_int(dev);
241 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
244 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
248 adap = &dev->adapter;
249 i2c_set_adapdata(adap, dev);
250 adap->owner = THIS_MODULE;
251 adap->class = I2C_CLASS_DEPRECATED;
252 strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
254 adap->algo = &i2c_dw_algo;
255 adap->dev.parent = &pdev->dev;
256 adap->dev.of_node = pdev->dev.of_node;
258 r = i2c_add_numbered_adapter(adap);
260 dev_err(&pdev->dev, "failure adding adapter\n");
264 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
265 pm_runtime_use_autosuspend(&pdev->dev);
266 pm_runtime_set_active(&pdev->dev);
267 pm_runtime_enable(&pdev->dev);
272 static int dw_i2c_remove(struct platform_device *pdev)
274 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
276 pm_runtime_get_sync(&pdev->dev);
278 i2c_del_adapter(&dev->adapter);
282 pm_runtime_put(&pdev->dev);
283 pm_runtime_disable(&pdev->dev);
285 if (ACPI_COMPANION(&pdev->dev))
286 dw_i2c_acpi_unconfigure(pdev);
292 static const struct of_device_id dw_i2c_of_match[] = {
293 { .compatible = "snps,designware-i2c", },
296 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
300 static int dw_i2c_suspend(struct device *dev)
302 struct platform_device *pdev = to_platform_device(dev);
303 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
305 i2c_dw_disable(i_dev);
306 clk_disable_unprepare(i_dev->clk);
311 static int dw_i2c_resume(struct device *dev)
313 struct platform_device *pdev = to_platform_device(dev);
314 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
316 clk_prepare_enable(i_dev->clk);
323 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
324 dw_i2c_resume, NULL);
326 /* work with hotplug and coldplug */
327 MODULE_ALIAS("platform:i2c_designware");
329 static struct platform_driver dw_i2c_driver = {
330 .probe = dw_i2c_probe,
331 .remove = dw_i2c_remove,
333 .name = "i2c_designware",
334 .owner = THIS_MODULE,
335 .of_match_table = of_match_ptr(dw_i2c_of_match),
336 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
337 .pm = &dw_i2c_dev_pm_ops,
341 static int __init dw_i2c_init_driver(void)
343 return platform_driver_register(&dw_i2c_driver);
345 subsys_initcall(dw_i2c_init_driver);
347 static void __exit dw_i2c_exit_driver(void)
349 platform_driver_unregister(&dw_i2c_driver);
351 module_exit(dw_i2c_exit_driver);
353 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
354 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
355 MODULE_LICENSE("GPL");