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);
110 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, NULL);
111 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, NULL);
113 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
114 if (id && id->driver_data)
115 dev->flags |= (u32)id->driver_data;
120 static const struct acpi_device_id dw_i2c_acpi_match[] = {
126 { "808622C1", MODEL_CHERRYTRAIL },
127 { "AMD0010", ACCESS_INTR_MASK },
128 { "AMDI0010", ACCESS_INTR_MASK },
133 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
135 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
141 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
143 if (IS_ERR(i_dev->clk))
144 return PTR_ERR(i_dev->clk);
147 return clk_prepare_enable(i_dev->clk);
149 clk_disable_unprepare(i_dev->clk);
153 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
155 u32 param, tx_fifo_depth, rx_fifo_depth;
158 * Try to detect the FIFO depth if not set by interface driver,
159 * the depth could be from 2 to 256 from HW spec.
161 param = i2c_dw_read_comp_param(dev);
162 tx_fifo_depth = ((param >> 16) & 0xff) + 1;
163 rx_fifo_depth = ((param >> 8) & 0xff) + 1;
164 if (!dev->tx_fifo_depth) {
165 dev->tx_fifo_depth = tx_fifo_depth;
166 dev->rx_fifo_depth = rx_fifo_depth;
167 dev->adapter.nr = id;
168 } else if (tx_fifo_depth >= 2) {
169 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
171 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
176 static int dw_i2c_plat_probe(struct platform_device *pdev)
178 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
179 struct dw_i2c_dev *dev;
180 struct i2c_adapter *adap;
181 struct resource *mem;
183 u32 acpi_speed, ht = 0;
185 irq = platform_get_irq(pdev, 0);
189 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
193 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
194 dev->base = devm_ioremap_resource(&pdev->dev, mem);
195 if (IS_ERR(dev->base))
196 return PTR_ERR(dev->base);
198 dev->dev = &pdev->dev;
200 platform_set_drvdata(pdev, dev);
203 dev->clk_freq = pdata->i2c_scl_freq;
205 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
207 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
208 &dev->sda_falling_time);
209 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
210 &dev->scl_falling_time);
211 device_property_read_u32(&pdev->dev, "clock-frequency",
215 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
217 * Find bus speed from the "clock-frequency" device property, ACPI
218 * or by using fast mode if neither is set.
220 if (acpi_speed && dev->clk_freq)
221 dev->clk_freq = min(dev->clk_freq, acpi_speed);
222 else if (acpi_speed || dev->clk_freq)
223 dev->clk_freq = max(dev->clk_freq, acpi_speed);
225 dev->clk_freq = 400000;
227 if (has_acpi_companion(&pdev->dev))
228 dw_i2c_acpi_configure(pdev);
231 * Only standard mode at 100kHz, fast mode at 400kHz,
232 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
234 if (dev->clk_freq != 100000 && dev->clk_freq != 400000
235 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
237 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
241 r = i2c_dw_probe_lock_support(dev);
245 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
247 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
248 DW_IC_CON_RESTART_EN;
250 switch (dev->clk_freq) {
252 dev->master_cfg |= DW_IC_CON_SPEED_STD;
255 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
258 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
261 dev->clk = devm_clk_get(&pdev->dev, NULL);
262 if (!i2c_dw_plat_prepare_clk(dev, true)) {
263 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
265 if (!dev->sda_hold_time && ht)
266 dev->sda_hold_time = div_u64(
267 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
271 dw_i2c_set_fifo_size(dev, pdev->id);
273 adap = &dev->adapter;
274 adap->owner = THIS_MODULE;
275 adap->class = I2C_CLASS_DEPRECATED;
276 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
277 adap->dev.of_node = pdev->dev.of_node;
279 if (dev->pm_runtime_disabled) {
280 pm_runtime_forbid(&pdev->dev);
282 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
283 pm_runtime_use_autosuspend(&pdev->dev);
284 pm_runtime_set_active(&pdev->dev);
285 pm_runtime_enable(&pdev->dev);
288 r = i2c_dw_probe(dev);
289 if (r && !dev->pm_runtime_disabled)
290 pm_runtime_disable(&pdev->dev);
295 static int dw_i2c_plat_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 if (!dev->pm_runtime_disabled)
308 pm_runtime_disable(&pdev->dev);
310 i2c_dw_remove_lock_support(dev);
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_plat_prepare(struct device *dev)
326 return pm_runtime_suspended(dev);
329 static void dw_i2c_plat_complete(struct device *dev)
331 if (dev->power.direct_complete)
332 pm_request_resume(dev);
335 #define dw_i2c_plat_prepare NULL
336 #define dw_i2c_plat_complete NULL
340 static int dw_i2c_plat_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 i2c_dw_plat_prepare_clk(i_dev, false);
351 static int dw_i2c_plat_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 i2c_dw_plat_prepare_clk(i_dev, true);
358 if (!i_dev->pm_runtime_disabled)
364 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
365 .prepare = dw_i2c_plat_prepare,
366 .complete = dw_i2c_plat_complete,
367 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
368 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_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_plat_probe,
381 .remove = dw_i2c_plat_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");