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
;
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 const struct acpi_device_id
*id
;
100 dev
->adapter
.nr
= -1;
101 dev
->tx_fifo_depth
= 32;
102 dev
->rx_fifo_depth
= 32;
105 * Try to get SDA hold time and *CNT values from an ACPI method if
106 * it exists for both supported speed modes.
108 dw_i2c_acpi_params(pdev
, "SSCN", &dev
->ss_hcnt
, &dev
->ss_lcnt
, NULL
);
109 dw_i2c_acpi_params(pdev
, "FMCN", &dev
->fs_hcnt
, &dev
->fs_lcnt
,
110 &dev
->sda_hold_time
);
111 dw_i2c_acpi_params(pdev
, "FPCN", &dev
->fp_hcnt
, &dev
->fp_lcnt
, NULL
);
112 dw_i2c_acpi_params(pdev
, "HSCN", &dev
->hs_hcnt
, &dev
->hs_lcnt
, NULL
);
114 id
= acpi_match_device(pdev
->dev
.driver
->acpi_match_table
, &pdev
->dev
);
115 if (id
&& id
->driver_data
)
116 dev
->accessor_flags
|= (u32
)id
->driver_data
;
121 static const struct acpi_device_id dw_i2c_acpi_match
[] = {
128 { "AMD0010", ACCESS_INTR_MASK
},
129 { "AMDI0010", ACCESS_INTR_MASK
},
134 MODULE_DEVICE_TABLE(acpi
, dw_i2c_acpi_match
);
136 static inline int dw_i2c_acpi_configure(struct platform_device
*pdev
)
142 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev
*i_dev
, bool prepare
)
144 if (IS_ERR(i_dev
->clk
))
145 return PTR_ERR(i_dev
->clk
);
148 return clk_prepare_enable(i_dev
->clk
);
150 clk_disable_unprepare(i_dev
->clk
);
154 static void dw_i2c_set_fifo_size(struct dw_i2c_dev
*dev
, int id
)
156 u32 param
, tx_fifo_depth
, rx_fifo_depth
;
159 * Try to detect the FIFO depth if not set by interface driver,
160 * the depth could be from 2 to 256 from HW spec.
162 param
= i2c_dw_read_comp_param(dev
);
163 tx_fifo_depth
= ((param
>> 16) & 0xff) + 1;
164 rx_fifo_depth
= ((param
>> 8) & 0xff) + 1;
165 if (!dev
->tx_fifo_depth
) {
166 dev
->tx_fifo_depth
= tx_fifo_depth
;
167 dev
->rx_fifo_depth
= rx_fifo_depth
;
168 dev
->adapter
.nr
= id
;
169 } else if (tx_fifo_depth
>= 2) {
170 dev
->tx_fifo_depth
= min_t(u32
, dev
->tx_fifo_depth
,
172 dev
->rx_fifo_depth
= min_t(u32
, dev
->rx_fifo_depth
,
177 static int dw_i2c_plat_probe(struct platform_device
*pdev
)
179 struct dw_i2c_platform_data
*pdata
= dev_get_platdata(&pdev
->dev
);
180 struct dw_i2c_dev
*dev
;
181 struct i2c_adapter
*adap
;
182 struct resource
*mem
;
184 u32 acpi_speed
, ht
= 0;
186 irq
= platform_get_irq(pdev
, 0);
190 dev
= devm_kzalloc(&pdev
->dev
, sizeof(struct dw_i2c_dev
), GFP_KERNEL
);
194 mem
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
195 dev
->base
= devm_ioremap_resource(&pdev
->dev
, mem
);
196 if (IS_ERR(dev
->base
))
197 return PTR_ERR(dev
->base
);
199 dev
->dev
= &pdev
->dev
;
201 platform_set_drvdata(pdev
, dev
);
203 dev
->rst
= devm_reset_control_get_optional_exclusive(&pdev
->dev
, NULL
);
204 if (IS_ERR(dev
->rst
)) {
205 if (PTR_ERR(dev
->rst
) == -EPROBE_DEFER
)
206 return -EPROBE_DEFER
;
208 reset_control_deassert(dev
->rst
);
212 dev
->clk_freq
= pdata
->i2c_scl_freq
;
214 device_property_read_u32(&pdev
->dev
, "i2c-sda-hold-time-ns",
216 device_property_read_u32(&pdev
->dev
, "i2c-sda-falling-time-ns",
217 &dev
->sda_falling_time
);
218 device_property_read_u32(&pdev
->dev
, "i2c-scl-falling-time-ns",
219 &dev
->scl_falling_time
);
220 device_property_read_u32(&pdev
->dev
, "clock-frequency",
224 acpi_speed
= i2c_acpi_find_bus_speed(&pdev
->dev
);
226 * Find bus speed from the "clock-frequency" device property, ACPI
227 * or by using fast mode if neither is set.
229 if (acpi_speed
&& dev
->clk_freq
)
230 dev
->clk_freq
= min(dev
->clk_freq
, acpi_speed
);
231 else if (acpi_speed
|| dev
->clk_freq
)
232 dev
->clk_freq
= max(dev
->clk_freq
, acpi_speed
);
234 dev
->clk_freq
= 400000;
236 if (has_acpi_companion(&pdev
->dev
))
237 dw_i2c_acpi_configure(pdev
);
240 * Only standard mode at 100kHz, fast mode at 400kHz,
241 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
243 if (dev
->clk_freq
!= 100000 && dev
->clk_freq
!= 400000
244 && dev
->clk_freq
!= 1000000 && dev
->clk_freq
!= 3400000) {
246 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
251 r
= i2c_dw_eval_lock_support(dev
);
255 dev
->functionality
= I2C_FUNC_10BIT_ADDR
| DW_IC_DEFAULT_FUNCTIONALITY
;
257 dev
->master_cfg
= DW_IC_CON_MASTER
| DW_IC_CON_SLAVE_DISABLE
|
258 DW_IC_CON_RESTART_EN
;
260 switch (dev
->clk_freq
) {
262 dev
->master_cfg
|= DW_IC_CON_SPEED_STD
;
265 dev
->master_cfg
|= DW_IC_CON_SPEED_HIGH
;
268 dev
->master_cfg
|= DW_IC_CON_SPEED_FAST
;
271 dev
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
272 if (!i2c_dw_plat_prepare_clk(dev
, true)) {
273 dev
->get_clk_rate_khz
= i2c_dw_get_clk_rate_khz
;
275 if (!dev
->sda_hold_time
&& ht
)
276 dev
->sda_hold_time
= div_u64(
277 (u64
)dev
->get_clk_rate_khz(dev
) * ht
+ 500000,
281 dw_i2c_set_fifo_size(dev
, pdev
->id
);
283 adap
= &dev
->adapter
;
284 adap
->owner
= THIS_MODULE
;
285 adap
->class = I2C_CLASS_DEPRECATED
;
286 ACPI_COMPANION_SET(&adap
->dev
, ACPI_COMPANION(&pdev
->dev
));
287 adap
->dev
.of_node
= pdev
->dev
.of_node
;
289 if (dev
->pm_runtime_disabled
) {
290 pm_runtime_forbid(&pdev
->dev
);
292 pm_runtime_set_autosuspend_delay(&pdev
->dev
, 1000);
293 pm_runtime_use_autosuspend(&pdev
->dev
);
294 pm_runtime_set_active(&pdev
->dev
);
295 pm_runtime_enable(&pdev
->dev
);
298 r
= i2c_dw_probe(dev
);
305 if (!dev
->pm_runtime_disabled
)
306 pm_runtime_disable(&pdev
->dev
);
308 if (!IS_ERR_OR_NULL(dev
->rst
))
309 reset_control_assert(dev
->rst
);
313 static int dw_i2c_plat_remove(struct platform_device
*pdev
)
315 struct dw_i2c_dev
*dev
= platform_get_drvdata(pdev
);
317 pm_runtime_get_sync(&pdev
->dev
);
319 i2c_del_adapter(&dev
->adapter
);
323 pm_runtime_dont_use_autosuspend(&pdev
->dev
);
324 pm_runtime_put_sync(&pdev
->dev
);
325 if (!dev
->pm_runtime_disabled
)
326 pm_runtime_disable(&pdev
->dev
);
327 if (!IS_ERR_OR_NULL(dev
->rst
))
328 reset_control_assert(dev
->rst
);
334 static const struct of_device_id dw_i2c_of_match
[] = {
335 { .compatible
= "snps,designware-i2c", },
338 MODULE_DEVICE_TABLE(of
, dw_i2c_of_match
);
341 #ifdef CONFIG_PM_SLEEP
342 static int dw_i2c_plat_prepare(struct device
*dev
)
344 return pm_runtime_suspended(dev
);
347 static void dw_i2c_plat_complete(struct device
*dev
)
349 if (dev
->power
.direct_complete
)
350 pm_request_resume(dev
);
353 #define dw_i2c_plat_prepare NULL
354 #define dw_i2c_plat_complete NULL
358 static int dw_i2c_plat_suspend(struct device
*dev
)
360 struct platform_device
*pdev
= to_platform_device(dev
);
361 struct dw_i2c_dev
*i_dev
= platform_get_drvdata(pdev
);
363 i2c_dw_disable(i_dev
);
364 i2c_dw_plat_prepare_clk(i_dev
, false);
369 static int dw_i2c_plat_resume(struct device
*dev
)
371 struct platform_device
*pdev
= to_platform_device(dev
);
372 struct dw_i2c_dev
*i_dev
= platform_get_drvdata(pdev
);
374 i2c_dw_plat_prepare_clk(i_dev
, true);
376 if (!i_dev
->pm_runtime_disabled
)
382 static const struct dev_pm_ops dw_i2c_dev_pm_ops
= {
383 .prepare
= dw_i2c_plat_prepare
,
384 .complete
= dw_i2c_plat_complete
,
385 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend
, dw_i2c_plat_resume
)
386 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend
, dw_i2c_plat_resume
, NULL
)
389 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
391 #define DW_I2C_DEV_PMOPS NULL
394 /* work with hotplug and coldplug */
395 MODULE_ALIAS("platform:i2c_designware");
397 static struct platform_driver dw_i2c_driver
= {
398 .probe
= dw_i2c_plat_probe
,
399 .remove
= dw_i2c_plat_remove
,
401 .name
= "i2c_designware",
402 .of_match_table
= of_match_ptr(dw_i2c_of_match
),
403 .acpi_match_table
= ACPI_PTR(dw_i2c_acpi_match
),
404 .pm
= DW_I2C_DEV_PMOPS
,
408 static int __init
dw_i2c_init_driver(void)
410 return platform_driver_register(&dw_i2c_driver
);
412 subsys_initcall(dw_i2c_init_driver
);
414 static void __exit
dw_i2c_exit_driver(void)
416 platform_driver_unregister(&dw_i2c_driver
);
418 module_exit(dw_i2c_exit_driver
);
420 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
421 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
422 MODULE_LICENSE("GPL");