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/reset.h>
42 #include <linux/slab.h>
43 #include <linux/acpi.h>
44 #include <linux/platform_data/i2c-designware.h>
45 #include "i2c-designware-core.h"
47 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
49 return clk_get_rate(dev->clk)/1000;
54 * The HCNT/LCNT information coming from ACPI should be the most accurate
55 * for given platform. However, some systems get it wrong. On such systems
56 * we get better results by calculating those based on the input clock.
58 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
60 .ident = "Dell Inspiron 7348",
62 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
63 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
69 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
70 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
72 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
73 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
74 union acpi_object *obj;
76 if (dmi_check_system(dw_i2c_no_acpi_params))
79 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
82 obj = (union acpi_object *)buf.pointer;
83 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
84 const union acpi_object *objs = obj->package.elements;
86 *hcnt = (u16)objs[0].integer.value;
87 *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 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
98 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
99 const struct acpi_device_id *id;
100 struct acpi_device *adev;
103 dev->adapter.nr = -1;
104 dev->tx_fifo_depth = 32;
105 dev->rx_fifo_depth = 32;
108 * Try to get SDA hold time and *CNT values from an ACPI method for
109 * selected speed modes.
111 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
112 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
113 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
114 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
116 switch (dev->clk_freq) {
118 dev->sda_hold_time = ss_ht;
121 dev->sda_hold_time = fp_ht;
124 dev->sda_hold_time = hs_ht;
128 dev->sda_hold_time = fs_ht;
132 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
133 if (id && id->driver_data)
134 dev->flags |= (u32)id->driver_data;
136 if (acpi_bus_get_device(handle, &adev))
140 * Cherrytrail I2C7 gets used for the PMIC which gets accessed
141 * through ACPI opregions during late suspend / early resume
144 uid = adev->pnp.unique_id;
145 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
146 dev->pm_disabled = true;
151 static const struct acpi_device_id dw_i2c_acpi_match[] = {
157 { "808622C1", MODEL_CHERRYTRAIL },
158 { "AMD0010", ACCESS_INTR_MASK },
159 { "AMDI0010", ACCESS_INTR_MASK },
166 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
168 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
174 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
176 if (IS_ERR(i_dev->clk))
177 return PTR_ERR(i_dev->clk);
180 return clk_prepare_enable(i_dev->clk);
182 clk_disable_unprepare(i_dev->clk);
186 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
188 u32 param, tx_fifo_depth, rx_fifo_depth;
191 * Try to detect the FIFO depth if not set by interface driver,
192 * the depth could be from 2 to 256 from HW spec.
194 param = i2c_dw_read_comp_param(dev);
195 tx_fifo_depth = ((param >> 16) & 0xff) + 1;
196 rx_fifo_depth = ((param >> 8) & 0xff) + 1;
197 if (!dev->tx_fifo_depth) {
198 dev->tx_fifo_depth = tx_fifo_depth;
199 dev->rx_fifo_depth = rx_fifo_depth;
200 dev->adapter.nr = id;
201 } else if (tx_fifo_depth >= 2) {
202 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
204 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
209 static int dw_i2c_plat_probe(struct platform_device *pdev)
211 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
212 struct dw_i2c_dev *dev;
213 struct i2c_adapter *adap;
214 struct resource *mem;
216 u32 acpi_speed, ht = 0;
218 irq = platform_get_irq(pdev, 0);
222 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
226 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
227 dev->base = devm_ioremap_resource(&pdev->dev, mem);
228 if (IS_ERR(dev->base))
229 return PTR_ERR(dev->base);
231 dev->dev = &pdev->dev;
233 platform_set_drvdata(pdev, dev);
235 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
236 if (IS_ERR(dev->rst)) {
237 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
238 return -EPROBE_DEFER;
240 reset_control_deassert(dev->rst);
244 dev->clk_freq = pdata->i2c_scl_freq;
246 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
248 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
249 &dev->sda_falling_time);
250 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
251 &dev->scl_falling_time);
252 device_property_read_u32(&pdev->dev, "clock-frequency",
256 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
258 * Find bus speed from the "clock-frequency" device property, ACPI
259 * or by using fast mode if neither is set.
261 if (acpi_speed && dev->clk_freq)
262 dev->clk_freq = min(dev->clk_freq, acpi_speed);
263 else if (acpi_speed || dev->clk_freq)
264 dev->clk_freq = max(dev->clk_freq, acpi_speed);
266 dev->clk_freq = 400000;
268 if (has_acpi_companion(&pdev->dev))
269 dw_i2c_acpi_configure(pdev);
272 * Only standard mode at 100kHz, fast mode at 400kHz,
273 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
275 if (dev->clk_freq != 100000 && dev->clk_freq != 400000
276 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
278 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
283 r = i2c_dw_probe_lock_support(dev);
287 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
289 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
290 DW_IC_CON_RESTART_EN;
292 switch (dev->clk_freq) {
294 dev->master_cfg |= DW_IC_CON_SPEED_STD;
297 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
300 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
303 dev->clk = devm_clk_get(&pdev->dev, NULL);
304 if (!i2c_dw_plat_prepare_clk(dev, true)) {
305 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
307 if (!dev->sda_hold_time && ht)
308 dev->sda_hold_time = div_u64(
309 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
313 dw_i2c_set_fifo_size(dev, pdev->id);
315 adap = &dev->adapter;
316 adap->owner = THIS_MODULE;
317 adap->class = I2C_CLASS_DEPRECATED;
318 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
319 adap->dev.of_node = pdev->dev.of_node;
321 if (dev->pm_disabled) {
322 pm_runtime_forbid(&pdev->dev);
324 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
325 pm_runtime_use_autosuspend(&pdev->dev);
326 pm_runtime_set_active(&pdev->dev);
327 pm_runtime_enable(&pdev->dev);
330 r = i2c_dw_probe(dev);
337 if (!dev->pm_disabled)
338 pm_runtime_disable(&pdev->dev);
340 if (!IS_ERR_OR_NULL(dev->rst))
341 reset_control_assert(dev->rst);
345 static int dw_i2c_plat_remove(struct platform_device *pdev)
347 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
349 pm_runtime_get_sync(&pdev->dev);
351 i2c_del_adapter(&dev->adapter);
355 pm_runtime_dont_use_autosuspend(&pdev->dev);
356 pm_runtime_put_sync(&pdev->dev);
357 if (!dev->pm_disabled)
358 pm_runtime_disable(&pdev->dev);
359 if (!IS_ERR_OR_NULL(dev->rst))
360 reset_control_assert(dev->rst);
362 i2c_dw_remove_lock_support(dev);
368 static const struct of_device_id dw_i2c_of_match[] = {
369 { .compatible = "snps,designware-i2c", },
372 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
375 #ifdef CONFIG_PM_SLEEP
376 static int dw_i2c_plat_prepare(struct device *dev)
378 return pm_runtime_suspended(dev);
381 static void dw_i2c_plat_complete(struct device *dev)
383 if (dev->power.direct_complete)
384 pm_request_resume(dev);
387 #define dw_i2c_plat_prepare NULL
388 #define dw_i2c_plat_complete NULL
392 static int dw_i2c_plat_suspend(struct device *dev)
394 struct platform_device *pdev = to_platform_device(dev);
395 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
397 i2c_dw_disable(i_dev);
398 i2c_dw_plat_prepare_clk(i_dev, false);
403 static int dw_i2c_plat_resume(struct device *dev)
405 struct platform_device *pdev = to_platform_device(dev);
406 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
408 i2c_dw_plat_prepare_clk(i_dev, true);
414 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
415 .prepare = dw_i2c_plat_prepare,
416 .complete = dw_i2c_plat_complete,
417 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
418 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
421 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
423 #define DW_I2C_DEV_PMOPS NULL
426 /* work with hotplug and coldplug */
427 MODULE_ALIAS("platform:i2c_designware");
429 static struct platform_driver dw_i2c_driver = {
430 .probe = dw_i2c_plat_probe,
431 .remove = dw_i2c_plat_remove,
433 .name = "i2c_designware",
434 .of_match_table = of_match_ptr(dw_i2c_of_match),
435 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
436 .pm = DW_I2C_DEV_PMOPS,
440 static int __init dw_i2c_init_driver(void)
442 return platform_driver_register(&dw_i2c_driver);
444 subsys_initcall(dw_i2c_init_driver);
446 static void __exit dw_i2c_exit_driver(void)
448 platform_driver_unregister(&dw_i2c_driver);
450 module_exit(dw_i2c_exit_driver);
452 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
453 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
454 MODULE_LICENSE("GPL");