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/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>
35 #include <linux/platform_device.h>
37 #include <linux/pm_runtime.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"
44 static struct i2c_algorithm i2c_dw_algo = {
45 .master_xfer = i2c_dw_xfer,
46 .functionality = i2c_dw_func,
48 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
50 return clk_get_rate(dev->clk)/1000;
54 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
55 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
57 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
58 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
59 union acpi_object *obj;
61 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
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;
68 *hcnt = (u16)objs[0].integer.value;
69 *lcnt = (u16)objs[1].integer.value;
71 *sda_hold = (u32)objs[2].integer.value;
77 static int dw_i2c_acpi_configure(struct platform_device *pdev)
79 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
80 const struct acpi_device_id *id;
83 dev->tx_fifo_depth = 32;
84 dev->rx_fifo_depth = 32;
87 * Try to get SDA hold time and *CNT values from an ACPI method if
88 * it exists for both supported speed modes.
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,
95 * Provide a way for Designware I2C host controllers that are not
96 * based on Intel LPSS to specify their input clock frequency via
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);
107 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev)
109 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
110 const struct acpi_device_id *id;
112 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
113 if (id && id->driver_data)
114 clk_unregister(dev->clk);
117 static const struct acpi_device_id dw_i2c_acpi_match[] = {
124 { "AMD0010", 133 * 1000 * 1000 },
127 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
129 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
133 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { }
136 static int dw_i2c_probe(struct platform_device *pdev)
138 struct dw_i2c_dev *dev;
139 struct i2c_adapter *adap;
140 struct resource *mem;
141 struct dw_i2c_platform_data *pdata;
143 u32 clk_freq, ht = 0;
145 irq = platform_get_irq(pdev, 0);
147 dev_err(&pdev->dev, "no irq resource?\n");
148 return irq; /* -ENXIO */
151 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
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);
160 init_completion(&dev->cmd_complete);
161 mutex_init(&dev->lock);
162 dev->dev = &pdev->dev;
164 platform_set_drvdata(pdev, dev);
166 /* fast mode by default because of legacy reasons */
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);
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);
182 of_property_read_u32(pdev->dev.of_node, "clock-frequency",
185 /* Only standard mode at 100kHz and fast mode at 400kHz
188 if (clk_freq != 100000 && clk_freq != 400000) {
189 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported");
193 pdata = dev_get_platdata(&pdev->dev);
195 clk_freq = pdata->i2c_scl_freq;
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;
209 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
210 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
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);
218 if (!dev->sda_hold_time && ht) {
219 u32 ic_clk = dev->get_clk_rate_khz(dev);
221 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
225 if (!dev->tx_fifo_depth) {
226 u32 param1 = i2c_dw_read_comp_param(dev);
228 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
229 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1;
230 dev->adapter.nr = pdev->id;
232 r = i2c_dw_init(dev);
236 i2c_dw_disable_int(dev);
237 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
240 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
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",
250 adap->algo = &i2c_dw_algo;
251 adap->dev.parent = &pdev->dev;
252 adap->dev.of_node = pdev->dev.of_node;
254 r = i2c_add_numbered_adapter(adap);
256 dev_err(&pdev->dev, "failure adding adapter\n");
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);
268 static int dw_i2c_remove(struct platform_device *pdev)
270 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
272 pm_runtime_get_sync(&pdev->dev);
274 i2c_del_adapter(&dev->adapter);
278 pm_runtime_put(&pdev->dev);
279 pm_runtime_disable(&pdev->dev);
281 if (ACPI_COMPANION(&pdev->dev))
282 dw_i2c_acpi_unconfigure(pdev);
288 static const struct of_device_id dw_i2c_of_match[] = {
289 { .compatible = "snps,designware-i2c", },
292 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
296 static int dw_i2c_suspend(struct device *dev)
298 struct platform_device *pdev = to_platform_device(dev);
299 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
301 i2c_dw_disable(i_dev);
302 clk_disable_unprepare(i_dev->clk);
307 static int dw_i2c_resume(struct device *dev)
309 struct platform_device *pdev = to_platform_device(dev);
310 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
312 clk_prepare_enable(i_dev->clk);
319 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend,
320 dw_i2c_resume, NULL);
322 /* work with hotplug and coldplug */
323 MODULE_ALIAS("platform:i2c_designware");
325 static struct platform_driver dw_i2c_driver = {
326 .probe = dw_i2c_probe,
327 .remove = dw_i2c_remove,
329 .name = "i2c_designware",
330 .of_match_table = of_match_ptr(dw_i2c_of_match),
331 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
332 .pm = &dw_i2c_dev_pm_ops,
336 static int __init dw_i2c_init_driver(void)
338 return platform_driver_register(&dw_i2c_driver);
340 subsys_initcall(dw_i2c_init_driver);
342 static void __exit dw_i2c_exit_driver(void)
344 platform_driver_unregister(&dw_i2c_driver);
346 module_exit(dw_i2c_exit_driver);
348 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
349 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
350 MODULE_LICENSE("GPL");