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 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
98 const struct acpi_device_id *id;
99 struct acpi_device *adev;
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 for
108 * selected speed modes.
110 switch (dev->clk_freq) {
112 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt,
113 &dev->sda_hold_time);
116 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt,
117 &dev->sda_hold_time);
120 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt,
121 &dev->sda_hold_time);
125 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
126 &dev->sda_hold_time);
130 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
131 if (id && id->driver_data)
132 dev->flags |= (u32)id->driver_data;
134 if (acpi_bus_get_device(handle, &adev))
138 * Cherrytrail I2C7 gets used for the PMIC which gets accessed
139 * through ACPI opregions during late suspend / early resume
142 uid = adev->pnp.unique_id;
143 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
144 dev->pm_disabled = true;
149 static const struct acpi_device_id dw_i2c_acpi_match[] = {
155 { "808622C1", MODEL_CHERRYTRAIL },
156 { "AMD0010", ACCESS_INTR_MASK },
157 { "AMDI0010", ACCESS_INTR_MASK },
164 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
166 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
172 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
174 if (IS_ERR(i_dev->clk))
175 return PTR_ERR(i_dev->clk);
178 return clk_prepare_enable(i_dev->clk);
180 clk_disable_unprepare(i_dev->clk);
184 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
186 u32 param, tx_fifo_depth, rx_fifo_depth;
189 * Try to detect the FIFO depth if not set by interface driver,
190 * the depth could be from 2 to 256 from HW spec.
192 param = i2c_dw_read_comp_param(dev);
193 tx_fifo_depth = ((param >> 16) & 0xff) + 1;
194 rx_fifo_depth = ((param >> 8) & 0xff) + 1;
195 if (!dev->tx_fifo_depth) {
196 dev->tx_fifo_depth = tx_fifo_depth;
197 dev->rx_fifo_depth = rx_fifo_depth;
198 dev->adapter.nr = id;
199 } else if (tx_fifo_depth >= 2) {
200 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
202 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
207 static int dw_i2c_plat_probe(struct platform_device *pdev)
209 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
210 struct dw_i2c_dev *dev;
211 struct i2c_adapter *adap;
212 struct resource *mem;
214 u32 acpi_speed, ht = 0;
216 irq = platform_get_irq(pdev, 0);
220 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
224 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225 dev->base = devm_ioremap_resource(&pdev->dev, mem);
226 if (IS_ERR(dev->base))
227 return PTR_ERR(dev->base);
229 dev->dev = &pdev->dev;
231 platform_set_drvdata(pdev, dev);
233 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
234 if (IS_ERR(dev->rst)) {
235 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
236 return -EPROBE_DEFER;
238 reset_control_deassert(dev->rst);
242 dev->clk_freq = pdata->i2c_scl_freq;
244 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
246 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
247 &dev->sda_falling_time);
248 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
249 &dev->scl_falling_time);
250 device_property_read_u32(&pdev->dev, "clock-frequency",
254 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
256 * Find bus speed from the "clock-frequency" device property, ACPI
257 * or by using fast mode if neither is set.
259 if (acpi_speed && dev->clk_freq)
260 dev->clk_freq = min(dev->clk_freq, acpi_speed);
261 else if (acpi_speed || dev->clk_freq)
262 dev->clk_freq = max(dev->clk_freq, acpi_speed);
264 dev->clk_freq = 400000;
266 if (has_acpi_companion(&pdev->dev))
267 dw_i2c_acpi_configure(pdev);
270 * Only standard mode at 100kHz, fast mode at 400kHz,
271 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
273 if (dev->clk_freq != 100000 && dev->clk_freq != 400000
274 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
276 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
281 r = i2c_dw_probe_lock_support(dev);
285 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
287 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
288 DW_IC_CON_RESTART_EN;
290 switch (dev->clk_freq) {
292 dev->master_cfg |= DW_IC_CON_SPEED_STD;
295 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
298 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
301 dev->clk = devm_clk_get(&pdev->dev, NULL);
302 if (!i2c_dw_plat_prepare_clk(dev, true)) {
303 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
305 if (!dev->sda_hold_time && ht)
306 dev->sda_hold_time = div_u64(
307 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
311 dw_i2c_set_fifo_size(dev, pdev->id);
313 adap = &dev->adapter;
314 adap->owner = THIS_MODULE;
315 adap->class = I2C_CLASS_DEPRECATED;
316 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
317 adap->dev.of_node = pdev->dev.of_node;
319 if (dev->pm_disabled) {
320 pm_runtime_forbid(&pdev->dev);
322 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
323 pm_runtime_use_autosuspend(&pdev->dev);
324 pm_runtime_set_active(&pdev->dev);
325 pm_runtime_enable(&pdev->dev);
328 r = i2c_dw_probe(dev);
335 if (!dev->pm_disabled)
336 pm_runtime_disable(&pdev->dev);
338 if (!IS_ERR_OR_NULL(dev->rst))
339 reset_control_assert(dev->rst);
343 static int dw_i2c_plat_remove(struct platform_device *pdev)
345 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
347 pm_runtime_get_sync(&pdev->dev);
349 i2c_del_adapter(&dev->adapter);
353 pm_runtime_dont_use_autosuspend(&pdev->dev);
354 pm_runtime_put_sync(&pdev->dev);
355 if (!dev->pm_disabled)
356 pm_runtime_disable(&pdev->dev);
357 if (!IS_ERR_OR_NULL(dev->rst))
358 reset_control_assert(dev->rst);
360 i2c_dw_remove_lock_support(dev);
366 static const struct of_device_id dw_i2c_of_match[] = {
367 { .compatible = "snps,designware-i2c", },
370 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
373 #ifdef CONFIG_PM_SLEEP
374 static int dw_i2c_plat_prepare(struct device *dev)
376 return pm_runtime_suspended(dev);
379 static void dw_i2c_plat_complete(struct device *dev)
381 if (dev->power.direct_complete)
382 pm_request_resume(dev);
385 #define dw_i2c_plat_prepare NULL
386 #define dw_i2c_plat_complete NULL
390 static int dw_i2c_plat_suspend(struct device *dev)
392 struct platform_device *pdev = to_platform_device(dev);
393 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
395 i2c_dw_disable(i_dev);
396 i2c_dw_plat_prepare_clk(i_dev, false);
401 static int dw_i2c_plat_resume(struct device *dev)
403 struct platform_device *pdev = to_platform_device(dev);
404 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
406 i2c_dw_plat_prepare_clk(i_dev, true);
412 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
413 .prepare = dw_i2c_plat_prepare,
414 .complete = dw_i2c_plat_complete,
415 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
416 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
419 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
421 #define DW_I2C_DEV_PMOPS NULL
424 /* work with hotplug and coldplug */
425 MODULE_ALIAS("platform:i2c_designware");
427 static struct platform_driver dw_i2c_driver = {
428 .probe = dw_i2c_plat_probe,
429 .remove = dw_i2c_plat_remove,
431 .name = "i2c_designware",
432 .of_match_table = of_match_ptr(dw_i2c_of_match),
433 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
434 .pm = DW_I2C_DEV_PMOPS,
438 static int __init dw_i2c_init_driver(void)
440 return platform_driver_register(&dw_i2c_driver);
442 subsys_initcall(dw_i2c_init_driver);
444 static void __exit dw_i2c_exit_driver(void)
446 platform_driver_unregister(&dw_i2c_driver);
448 module_exit(dw_i2c_exit_driver);
450 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
451 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
452 MODULE_LICENSE("GPL");