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>
39 #include <linux/property.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"
46 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
48 return clk_get_rate(dev->clk)/1000;
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.
57 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
59 .ident = "Dell Inspiron 7348",
61 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
62 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
68 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
69 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
71 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
72 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
73 union acpi_object *obj;
75 if (dmi_check_system(dw_i2c_no_acpi_params))
78 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
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;
85 *hcnt = (u16)objs[0].integer.value;
86 *lcnt = (u16)objs[1].integer.value;
88 *sda_hold = (u32)objs[2].integer.value;
94 static int dw_i2c_acpi_configure(struct platform_device *pdev)
96 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
97 const struct acpi_device_id *id;
100 dev->tx_fifo_depth = 32;
101 dev->rx_fifo_depth = 32;
104 * Try to get SDA hold time and *CNT values from an ACPI method if
105 * it exists for both supported speed modes.
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);
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;
118 static const struct acpi_device_id dw_i2c_acpi_match[] = {
125 { "AMD0010", ACCESS_INTR_MASK },
130 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
132 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
138 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
140 if (IS_ERR(i_dev->clk))
141 return PTR_ERR(i_dev->clk);
144 return clk_prepare_enable(i_dev->clk);
146 clk_disable_unprepare(i_dev->clk);
150 static int dw_i2c_plat_probe(struct platform_device *pdev)
152 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
153 struct dw_i2c_dev *dev;
154 struct i2c_adapter *adap;
155 struct resource *mem;
157 u32 clk_freq, ht = 0;
159 irq = platform_get_irq(pdev, 0);
163 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
167 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
168 dev->base = devm_ioremap_resource(&pdev->dev, mem);
169 if (IS_ERR(dev->base))
170 return PTR_ERR(dev->base);
172 dev->dev = &pdev->dev;
174 platform_set_drvdata(pdev, dev);
176 /* fast mode by default because of legacy reasons */
180 clk_freq = pdata->i2c_scl_freq;
182 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
184 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
185 &dev->sda_falling_time);
186 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
187 &dev->scl_falling_time);
188 device_property_read_u32(&pdev->dev, "clock-frequency",
192 if (has_acpi_companion(&pdev->dev))
193 dw_i2c_acpi_configure(pdev);
196 * Only standard mode at 100kHz and fast mode at 400kHz are supported.
198 if (clk_freq != 100000 && clk_freq != 400000) {
199 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
203 r = i2c_dw_eval_lock_support(dev);
209 I2C_FUNC_10BIT_ADDR |
210 I2C_FUNC_SMBUS_BYTE |
211 I2C_FUNC_SMBUS_BYTE_DATA |
212 I2C_FUNC_SMBUS_WORD_DATA |
213 I2C_FUNC_SMBUS_I2C_BLOCK;
214 if (clk_freq == 100000)
215 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
216 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD;
218 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
219 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
221 dev->clk = devm_clk_get(&pdev->dev, NULL);
222 if (!i2c_dw_plat_prepare_clk(dev, true)) {
223 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
225 if (!dev->sda_hold_time && ht)
226 dev->sda_hold_time = div_u64(
227 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
231 if (!dev->tx_fifo_depth) {
232 u32 param1 = i2c_dw_read_comp_param(dev);
234 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
235 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
236 dev->adapter.nr = pdev->id;
239 adap = &dev->adapter;
240 adap->owner = THIS_MODULE;
241 adap->class = I2C_CLASS_DEPRECATED;
242 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
243 adap->dev.of_node = pdev->dev.of_node;
245 if (dev->pm_runtime_disabled) {
246 pm_runtime_forbid(&pdev->dev);
248 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
249 pm_runtime_use_autosuspend(&pdev->dev);
250 pm_runtime_set_active(&pdev->dev);
251 pm_runtime_enable(&pdev->dev);
254 r = i2c_dw_probe(dev);
255 if (r && !dev->pm_runtime_disabled)
256 pm_runtime_disable(&pdev->dev);
261 static int dw_i2c_plat_remove(struct platform_device *pdev)
263 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
265 pm_runtime_get_sync(&pdev->dev);
267 i2c_del_adapter(&dev->adapter);
271 pm_runtime_dont_use_autosuspend(&pdev->dev);
272 pm_runtime_put_sync(&pdev->dev);
273 if (!dev->pm_runtime_disabled)
274 pm_runtime_disable(&pdev->dev);
280 static const struct of_device_id dw_i2c_of_match[] = {
281 { .compatible = "snps,designware-i2c", },
284 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
287 #ifdef CONFIG_PM_SLEEP
288 static int dw_i2c_plat_prepare(struct device *dev)
290 return pm_runtime_suspended(dev);
293 static void dw_i2c_plat_complete(struct device *dev)
295 if (dev->power.direct_complete)
296 pm_request_resume(dev);
299 #define dw_i2c_plat_prepare NULL
300 #define dw_i2c_plat_complete NULL
304 static int dw_i2c_plat_suspend(struct device *dev)
306 struct platform_device *pdev = to_platform_device(dev);
307 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
309 i2c_dw_disable(i_dev);
310 i2c_dw_plat_prepare_clk(i_dev, false);
315 static int dw_i2c_plat_resume(struct device *dev)
317 struct platform_device *pdev = to_platform_device(dev);
318 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
320 i2c_dw_plat_prepare_clk(i_dev, true);
322 if (!i_dev->pm_runtime_disabled)
328 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
329 .prepare = dw_i2c_plat_prepare,
330 .complete = dw_i2c_plat_complete,
331 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
332 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
335 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
337 #define DW_I2C_DEV_PMOPS NULL
340 /* work with hotplug and coldplug */
341 MODULE_ALIAS("platform:i2c_designware");
343 static struct platform_driver dw_i2c_driver = {
344 .probe = dw_i2c_plat_probe,
345 .remove = dw_i2c_plat_remove,
347 .name = "i2c_designware",
348 .of_match_table = of_match_ptr(dw_i2c_of_match),
349 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
350 .pm = DW_I2C_DEV_PMOPS,
354 static int __init dw_i2c_init_driver(void)
356 return platform_driver_register(&dw_i2c_driver);
358 subsys_initcall(dw_i2c_init_driver);
360 static void __exit dw_i2c_exit_driver(void)
362 platform_driver_unregister(&dw_i2c_driver);
364 module_exit(dw_i2c_exit_driver);
366 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
367 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
368 MODULE_LICENSE("GPL");