2 * Synopsys DesignWare I2C adapter driver.
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/acpi.h>
25 #include <linux/clk-provider.h>
26 #include <linux/clk.h>
27 #include <linux/delay.h>
28 #include <linux/dmi.h>
29 #include <linux/err.h>
30 #include <linux/errno.h>
31 #include <linux/i2c.h>
32 #include <linux/interrupt.h>
34 #include <linux/kernel.h>
35 #include <linux/module.h>
37 #include <linux/platform_data/i2c-designware.h>
38 #include <linux/platform_device.h>
40 #include <linux/pm_runtime.h>
41 #include <linux/property.h>
42 #include <linux/reset.h>
43 #include <linux/sched.h>
44 #include <linux/slab.h>
46 #include "i2c-designware-core.h"
48 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
50 return clk_get_rate(dev->clk)/1000;
55 * The HCNT/LCNT information coming from ACPI should be the most accurate
56 * for given platform. However, some systems get it wrong. On such systems
57 * we get better results by calculating those based on the input clock.
59 static const struct dmi_system_id dw_i2c_no_acpi_params[] = {
61 .ident = "Dell Inspiron 7348",
63 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
64 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"),
70 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
71 u16 *hcnt, u16 *lcnt, u32 *sda_hold)
73 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
74 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
75 union acpi_object *obj;
77 if (dmi_check_system(dw_i2c_no_acpi_params))
80 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
83 obj = (union acpi_object *)buf.pointer;
84 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
85 const union acpi_object *objs = obj->package.elements;
87 *hcnt = (u16)objs[0].integer.value;
88 *lcnt = (u16)objs[1].integer.value;
89 *sda_hold = (u32)objs[2].integer.value;
95 static int dw_i2c_acpi_configure(struct platform_device *pdev)
97 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
98 u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
99 acpi_handle handle = ACPI_HANDLE(&pdev->dev);
100 const struct acpi_device_id *id;
101 struct acpi_device *adev;
104 dev->adapter.nr = -1;
105 dev->tx_fifo_depth = 32;
106 dev->rx_fifo_depth = 32;
109 * Try to get SDA hold time and *CNT values from an ACPI method for
110 * selected speed modes.
112 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, &ss_ht);
113 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, &fp_ht);
114 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
115 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
117 switch (dev->clk_freq) {
119 dev->sda_hold_time = ss_ht;
122 dev->sda_hold_time = fp_ht;
125 dev->sda_hold_time = hs_ht;
129 dev->sda_hold_time = fs_ht;
133 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
134 if (id && id->driver_data)
135 dev->flags |= (u32)id->driver_data;
137 if (acpi_bus_get_device(handle, &adev))
141 * Cherrytrail I2C7 gets used for the PMIC which gets accessed
142 * through ACPI opregions during late suspend / early resume
145 uid = adev->pnp.unique_id;
146 if ((dev->flags & MODEL_CHERRYTRAIL) && !strcmp(uid, "7"))
147 dev->pm_disabled = true;
152 static const struct acpi_device_id dw_i2c_acpi_match[] = {
158 { "808622C1", MODEL_CHERRYTRAIL },
159 { "AMD0010", ACCESS_INTR_MASK },
160 { "AMDI0010", ACCESS_INTR_MASK },
167 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
169 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
175 static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
177 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
179 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
180 DW_IC_CON_RESTART_EN;
182 dev->mode = DW_IC_MASTER;
184 switch (dev->clk_freq) {
186 dev->master_cfg |= DW_IC_CON_SPEED_STD;
189 dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
192 dev->master_cfg |= DW_IC_CON_SPEED_FAST;
196 static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
198 dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY;
200 dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
201 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED;
203 dev->mode = DW_IC_SLAVE;
205 switch (dev->clk_freq) {
207 dev->slave_cfg |= DW_IC_CON_SPEED_STD;
210 dev->slave_cfg |= DW_IC_CON_SPEED_HIGH;
213 dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
217 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
219 if (IS_ERR(i_dev->clk))
220 return PTR_ERR(i_dev->clk);
223 return clk_prepare_enable(i_dev->clk);
225 clk_disable_unprepare(i_dev->clk);
229 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
231 u32 param, tx_fifo_depth, rx_fifo_depth;
234 * Try to detect the FIFO depth if not set by interface driver,
235 * the depth could be from 2 to 256 from HW spec.
237 param = i2c_dw_read_comp_param(dev);
238 tx_fifo_depth = ((param >> 16) & 0xff) + 1;
239 rx_fifo_depth = ((param >> 8) & 0xff) + 1;
240 if (!dev->tx_fifo_depth) {
241 dev->tx_fifo_depth = tx_fifo_depth;
242 dev->rx_fifo_depth = rx_fifo_depth;
243 dev->adapter.nr = id;
244 } else if (tx_fifo_depth >= 2) {
245 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth,
247 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
252 static void dw_i2c_plat_pm_cleanup(struct dw_i2c_dev *dev)
254 pm_runtime_disable(dev->dev);
256 if (dev->pm_disabled)
257 pm_runtime_put_noidle(dev->dev);
260 static int dw_i2c_plat_probe(struct platform_device *pdev)
262 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
263 struct i2c_adapter *adap;
264 struct dw_i2c_dev *dev;
265 u32 acpi_speed, ht = 0;
266 struct resource *mem;
268 static const int supported_speeds[] = {
269 0, 100000, 400000, 1000000, 3400000
272 irq = platform_get_irq(pdev, 0);
276 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
280 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
281 dev->base = devm_ioremap_resource(&pdev->dev, mem);
282 if (IS_ERR(dev->base))
283 return PTR_ERR(dev->base);
285 dev->dev = &pdev->dev;
287 platform_set_drvdata(pdev, dev);
289 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
290 if (IS_ERR(dev->rst)) {
291 if (PTR_ERR(dev->rst) == -EPROBE_DEFER)
292 return -EPROBE_DEFER;
294 reset_control_deassert(dev->rst);
298 dev->clk_freq = pdata->i2c_scl_freq;
300 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
302 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
303 &dev->sda_falling_time);
304 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
305 &dev->scl_falling_time);
306 device_property_read_u32(&pdev->dev, "clock-frequency",
310 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
312 * Some DSTDs use a non standard speed, round down to the lowest
315 for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
316 if (acpi_speed < supported_speeds[i])
319 acpi_speed = supported_speeds[i - 1];
322 * Find bus speed from the "clock-frequency" device property, ACPI
323 * or by using fast mode if neither is set.
325 if (acpi_speed && dev->clk_freq)
326 dev->clk_freq = min(dev->clk_freq, acpi_speed);
327 else if (acpi_speed || dev->clk_freq)
328 dev->clk_freq = max(dev->clk_freq, acpi_speed);
330 dev->clk_freq = 400000;
332 if (has_acpi_companion(&pdev->dev))
333 dw_i2c_acpi_configure(pdev);
336 * Only standard mode at 100kHz, fast mode at 400kHz,
337 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
339 if (dev->clk_freq != 100000 && dev->clk_freq != 400000
340 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
342 "%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
348 ret = i2c_dw_probe_lock_support(dev);
352 if (i2c_detect_slave_mode(&pdev->dev))
353 i2c_dw_configure_slave(dev);
355 i2c_dw_configure_master(dev);
357 dev->clk = devm_clk_get(&pdev->dev, NULL);
358 if (!i2c_dw_plat_prepare_clk(dev, true)) {
359 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
361 if (!dev->sda_hold_time && ht)
362 dev->sda_hold_time = div_u64(
363 (u64)dev->get_clk_rate_khz(dev) * ht + 500000,
367 dw_i2c_set_fifo_size(dev, pdev->id);
369 adap = &dev->adapter;
370 adap->owner = THIS_MODULE;
371 adap->class = I2C_CLASS_DEPRECATED;
372 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
373 adap->dev.of_node = pdev->dev.of_node;
375 /* The code below assumes runtime PM to be disabled. */
376 WARN_ON(pm_runtime_enabled(&pdev->dev));
378 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
379 pm_runtime_use_autosuspend(&pdev->dev);
380 pm_runtime_set_active(&pdev->dev);
382 if (dev->pm_disabled)
383 pm_runtime_get_noresume(&pdev->dev);
385 pm_runtime_enable(&pdev->dev);
387 if (dev->mode == DW_IC_SLAVE)
388 ret = i2c_dw_probe_slave(dev);
390 ret = i2c_dw_probe(dev);
398 dw_i2c_plat_pm_cleanup(dev);
400 if (!IS_ERR_OR_NULL(dev->rst))
401 reset_control_assert(dev->rst);
405 static int dw_i2c_plat_remove(struct platform_device *pdev)
407 struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
409 pm_runtime_get_sync(&pdev->dev);
411 i2c_del_adapter(&dev->adapter);
415 pm_runtime_dont_use_autosuspend(&pdev->dev);
416 pm_runtime_put_sync(&pdev->dev);
417 dw_i2c_plat_pm_cleanup(dev);
419 if (!IS_ERR_OR_NULL(dev->rst))
420 reset_control_assert(dev->rst);
422 i2c_dw_remove_lock_support(dev);
428 static const struct of_device_id dw_i2c_of_match[] = {
429 { .compatible = "snps,designware-i2c", },
432 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
435 #ifdef CONFIG_PM_SLEEP
436 static int dw_i2c_plat_prepare(struct device *dev)
438 return pm_runtime_suspended(dev);
441 static void dw_i2c_plat_complete(struct device *dev)
443 if (dev->power.direct_complete)
444 pm_request_resume(dev);
447 #define dw_i2c_plat_prepare NULL
448 #define dw_i2c_plat_complete NULL
452 static int dw_i2c_plat_suspend(struct device *dev)
454 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
456 if (i_dev->suspended) {
457 i_dev->skip_resume = true;
461 i_dev->disable(i_dev);
462 i2c_dw_plat_prepare_clk(i_dev, false);
464 i_dev->suspended = true;
469 static int dw_i2c_plat_resume(struct device *dev)
471 struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
473 if (!i_dev->suspended)
476 if (i_dev->skip_resume) {
477 i_dev->skip_resume = false;
481 i2c_dw_plat_prepare_clk(i_dev, true);
484 i_dev->suspended = false;
489 static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
490 .prepare = dw_i2c_plat_prepare,
491 .complete = dw_i2c_plat_complete,
492 SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
493 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
496 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
498 #define DW_I2C_DEV_PMOPS NULL
501 /* Work with hotplug and coldplug */
502 MODULE_ALIAS("platform:i2c_designware");
504 static struct platform_driver dw_i2c_driver = {
505 .probe = dw_i2c_plat_probe,
506 .remove = dw_i2c_plat_remove,
508 .name = "i2c_designware",
509 .of_match_table = of_match_ptr(dw_i2c_of_match),
510 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
511 .pm = DW_I2C_DEV_PMOPS,
515 static int __init dw_i2c_init_driver(void)
517 return platform_driver_register(&dw_i2c_driver);
519 subsys_initcall(dw_i2c_init_driver);
521 static void __exit dw_i2c_exit_driver(void)
523 platform_driver_unregister(&dw_i2c_driver);
525 module_exit(dw_i2c_exit_driver);
527 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
528 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
529 MODULE_LICENSE("GPL");