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.
21 * ----------------------------------------------------------------------------
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>
36 #include <linux/platform_device.h>
38 #include <linux/pm_runtime.h>
40 #include <linux/slab.h>
41 #include <linux/acpi.h>
42 #include <linux/platform_data/i2c-designware.h>
43 #include "i2c-designware-core.h"
45 static struct i2c_algorithm i2c_dw_algo = {
46 .master_xfer = i2c_dw_xfer,
47 .functionality = i2c_dw_func,
49 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
51 return clk_get_rate(dev->clk)/1000;
56 * The HCNT/LCNT information coming from ACPI should be the most accurate
57 * for given platform. However, some systems get it wrong. On such systems
58 * we get better results by calculating those based on the input clock.
60 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
62 .ident = "Dell Inspiron 7348",
64 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
65 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
71 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
72 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
74 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
75 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
76 union acpi_object *obj;
78 if (dmi_check_system(dw_i2c_no_acpi_params))
81 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
84 obj = (union acpi_object *)buf.pointer;
85 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
86 const union acpi_object *objs = obj->package.elements;
88 *hcnt = (u16)objs[0].integer.value;
89 *lcnt = (u16)objs[1].integer.value;
91 *sda_hold = (u32)objs[2].integer.value;
97 static int dw_i2c_acpi_configure(struct platform_device *pdev)
99 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
100 const struct acpi_device_id *id;
102 dev->adapter.nr = -1;
103 dev->tx_fifo_depth = 32;
104 dev->rx_fifo_depth = 32;
107 * Try to get SDA hold time and *CNT values from an ACPI method if
108 * it exists for both supported speed modes.
110 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL);
111 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
112 &dev->sda_hold_time);
115 * Provide a way for Designware I2C host controllers that are not
116 * based on Intel LPSS to specify their input clock frequency via
119 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
120 if (id && id->driver_data)
121 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL,
122 CLK_IS_ROOT, id->driver_data);
127 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
129 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
130 const struct acpi_device_id *id;
132 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
133 if (id && id->driver_data)
134 clk_unregister(dev->clk);
137 static const struct acpi_device_id dw_i2c_acpi_match[] = {
144 { "AMD0010", 133 * 1000 * 1000 },
147 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
149 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
153 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
156 static int dw_i2c_probe(struct platform_device *pdev)
158 struct dw_i2c_dev *dev;
159 struct i2c_adapter *adap;
160 struct resource *mem;
161 struct dw_i2c_platform_data *pdata;
163 u32 clk_freq, ht = 0;
165 irq = platform_get_irq(pdev, 0);
169 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
173 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
174 dev->base = devm_ioremap_resource(&pdev->dev, mem);
175 if (IS_ERR(dev->base))
176 return PTR_ERR(dev->base);
178 init_completion(&dev->cmd_complete);
179 mutex_init(&dev->lock);
180 dev->dev = &pdev->dev;
182 platform_set_drvdata(pdev, dev);
184 /* fast mode by default because of legacy reasons */
187 if (has_acpi_companion(&pdev->dev)) {
188 dw_i2c_acpi_configure(pdev);
189 } else if (pdev->dev.of_node) {
190 of_property_read_u32(pdev->dev.of_node,
191 "i2c-sda-hold-time-ns", &ht);
193 of_property_read_u32(pdev->dev.of_node,
194 "i2c-sda-falling-time-ns",
195 &dev->sda_falling_time);
196 of_property_read_u32(pdev->dev.of_node,
197 "i2c-scl-falling-time-ns",
198 &dev->scl_falling_time);
200 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
203 /* Only standard mode at 100kHz and fast mode at 400kHz
206 if (clk_freq != 100000 && clk_freq != 400000) {
207 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
211 pdata = dev_get_platdata(&pdev->dev);
213 clk_freq = pdata->i2c_scl_freq;
216 r = i2c_dw_eval_lock_support(dev);
222 I2C_FUNC_10BIT_ADDR |
223 I2C_FUNC_SMBUS_BYTE |
224 I2C_FUNC_SMBUS_BYTE_DATA |
225 I2C_FUNC_SMBUS_WORD_DATA |
226 I2C_FUNC_SMBUS_I2C_BLOCK;
227 if (clk_freq == 100000)
228 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
229 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
231 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
232 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
234 dev->clk = devm_clk_get(&pdev->dev, NULL);
235 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
236 if (IS_ERR(dev->clk))
237 return PTR_ERR(dev->clk);
238 clk_prepare_enable(dev->clk);
240 if (!dev->sda_hold_time && ht) {
241 u32 ic_clk = dev->get_clk_rate_khz(dev);
243 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
247 if (!dev->tx_fifo_depth) {
248 u32 param1 = i2c_dw_read_comp_param(dev);
250 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
251 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
252 dev->adapter.nr = pdev->id;
254 r = i2c_dw_init(dev);
258 i2c_dw_disable_int(dev);
259 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
262 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
266 adap = &dev->adapter;
267 i2c_set_adapdata(adap, dev);
268 adap->owner = THIS_MODULE;
269 adap->class = I2C_CLASS_DEPRECATED;
270 strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
272 adap->algo = &i2c_dw_algo;
273 adap->dev.parent = &pdev->dev;
274 adap->dev.of_node = pdev->dev.of_node;
276 if (dev->pm_runtime_disabled) {
277 pm_runtime_forbid(&pdev->dev);
279 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
280 pm_runtime_use_autosuspend(&pdev->dev);
281 pm_runtime_set_active(&pdev->dev);
282 pm_runtime_enable(&pdev->dev);
285 r = i2c_add_numbered_adapter(adap);
287 dev_err(&pdev->dev, "failure adding adapter\n");
288 pm_runtime_disable(&pdev->dev);
295 static int dw_i2c_remove(struct platform_device *pdev)
297 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
299 pm_runtime_get_sync(&pdev->dev);
301 i2c_del_adapter(&dev->adapter);
305 pm_runtime_dont_use_autosuspend(&pdev->dev);
306 pm_runtime_put_sync(&pdev->dev);
307 pm_runtime_disable(&pdev->dev);
309 if (has_acpi_companion(&pdev->dev))
310 dw_i2c_acpi_unconfigure(pdev);
316 static const struct of_device_id dw_i2c_of_match[] = {
317 { .compatible = "snps,designware-i2c", },
320 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
323 #ifdef CONFIG_PM_SLEEP
324 static int dw_i2c_prepare(struct device *dev)
326 return pm_runtime_suspended(dev);
329 static void dw_i2c_complete(struct device *dev)
331 if (dev->power.direct_complete)
332 pm_request_resume(dev);
335 #define dw_i2c_prepare NULL
336 #define dw_i2c_complete NULL
340 static int dw_i2c_suspend(struct device *dev)
342 struct platform_device *pdev = to_platform_device(dev);
343 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
345 i2c_dw_disable(i_dev);
346 clk_disable_unprepare(i_dev->clk);
351 static int dw_i2c_resume(struct device *dev)
353 struct platform_device *pdev = to_platform_device(dev);
354 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
356 clk_prepare_enable(i_dev->clk);
358 if (!i_dev->pm_runtime_disabled)
364 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
365 .prepare = dw_i2c_prepare,
366 .complete = dw_i2c_complete,
367 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_suspend, dw_i2c_resume)
368 SET_RUNTIME_PM_OPS(dw_i2c_suspend, dw_i2c_resume, NULL)
371 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
373 #define DW_I2C_DEV_PMOPS NULL
376 /* work with hotplug and coldplug */
377 MODULE_ALIAS("platform:i2c_designware");
379 static struct platform_driver dw_i2c_driver = {
380 .probe = dw_i2c_probe,
381 .remove = dw_i2c_remove,
383 .name = "i2c_designware",
384 .of_match_table = of_match_ptr(dw_i2c_of_match),
385 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
386 .pm = DW_I2C_DEV_PMOPS,
390 static int __init dw_i2c_init_driver(void)
392 return platform_driver_register(&dw_i2c_driver);
394 subsys_initcall(dw_i2c_init_driver);
396 static void __exit dw_i2c_exit_driver(void)
398 platform_driver_unregister(&dw_i2c_driver);
400 module_exit(dw_i2c_exit_driver);
402 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
403 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
404 MODULE_LICENSE("GPL");