1 /*
2  * Synopsys DesignWare I2C adapter driver (master only).
3  *
4  * Based on the TI DAVINCI I2C adapter driver.
5  *
6  * Copyright (C) 2006 Texas Instruments.
7  * Copyright (C) 2007 MontaVista Software Inc.
8  * Copyright (C) 2009 Provigent Ltd.
9  *
10  * ----------------------------------------------------------------------------
11  *
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.
16  *
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  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  * ----------------------------------------------------------------------------
26  *
27  */
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/delay.h>
31 #include <linux/i2c.h>
32 #include <linux/clk.h>
33 #include <linux/errno.h>
34 #include <linux/sched.h>
35 #include <linux/err.h>
36 #include <linux/interrupt.h>
37 #include <linux/of.h>
38 #include <linux/platform_device.h>
39 #include <linux/pm.h>
40 #include <linux/pm_runtime.h>
41 #include <linux/io.h>
42 #include <linux/slab.h>
43 #include <linux/acpi.h>
44 #include "i2c-designware-core.h"
45 
46 static struct i2c_algorithm i2c_dw_algo = {
47 	.master_xfer	= i2c_dw_xfer,
48 	.functionality	= i2c_dw_func,
49 };
50 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
51 {
52 	return clk_get_rate(dev->clk)/1000;
53 }
54 
55 #ifdef CONFIG_ACPI
56 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
57 			       u16 *hcnt, u16 *lcnt, u32 *sda_hold)
58 {
59 	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
60 	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
61 	union acpi_object *obj;
62 
63 	if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf)))
64 		return;
65 
66 	obj = (union acpi_object *)buf.pointer;
67 	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) {
68 		const union acpi_object *objs = obj->package.elements;
69 
70 		*hcnt = (u16)objs[0].integer.value;
71 		*lcnt = (u16)objs[1].integer.value;
72 		if (sda_hold)
73 			*sda_hold = (u32)objs[2].integer.value;
74 	}
75 
76 	kfree(buf.pointer);
77 }
78 
79 static int dw_i2c_acpi_configure(struct platform_device *pdev)
80 {
81 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
82 	bool fs_mode = dev->master_cfg & DW_IC_CON_SPEED_FAST;
83 
84 	if (!ACPI_HANDLE(&pdev->dev))
85 		return -ENODEV;
86 
87 	dev->adapter.nr = -1;
88 	dev->tx_fifo_depth = 32;
89 	dev->rx_fifo_depth = 32;
90 
91 	/*
92 	 * Try to get SDA hold time and *CNT values from an ACPI method if
93 	 * it exists for both supported speed modes.
94 	 */
95 	dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt,
96 			   fs_mode ? NULL : &dev->sda_hold_time);
97 	dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt,
98 			   fs_mode ? &dev->sda_hold_time : NULL);
99 
100 	return 0;
101 }
102 
103 static const struct acpi_device_id dw_i2c_acpi_match[] = {
104 	{ "INT33C2", 0 },
105 	{ "INT33C3", 0 },
106 	{ "INT3432", 0 },
107 	{ "INT3433", 0 },
108 	{ "80860F41", 0 },
109 	{ }
110 };
111 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
112 #else
113 static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
114 {
115 	return -ENODEV;
116 }
117 #endif
118 
119 static int dw_i2c_probe(struct platform_device *pdev)
120 {
121 	struct dw_i2c_dev *dev;
122 	struct i2c_adapter *adap;
123 	struct resource *mem;
124 	int irq, r;
125 
126 	irq = platform_get_irq(pdev, 0);
127 	if (irq < 0) {
128 		dev_err(&pdev->dev, "no irq resource?\n");
129 		return irq; /* -ENXIO */
130 	}
131 
132 	dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
133 	if (!dev)
134 		return -ENOMEM;
135 
136 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
137 	dev->base = devm_ioremap_resource(&pdev->dev, mem);
138 	if (IS_ERR(dev->base))
139 		return PTR_ERR(dev->base);
140 
141 	init_completion(&dev->cmd_complete);
142 	mutex_init(&dev->lock);
143 	dev->dev = &pdev->dev;
144 	dev->irq = irq;
145 	platform_set_drvdata(pdev, dev);
146 
147 	dev->clk = devm_clk_get(&pdev->dev, NULL);
148 	dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
149 
150 	if (IS_ERR(dev->clk))
151 		return PTR_ERR(dev->clk);
152 	clk_prepare_enable(dev->clk);
153 
154 	if (pdev->dev.of_node) {
155 		u32 ht = 0;
156 		u32 ic_clk = dev->get_clk_rate_khz(dev);
157 
158 		of_property_read_u32(pdev->dev.of_node,
159 					"i2c-sda-hold-time-ns", &ht);
160 		dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000,
161 					     1000000);
162 	}
163 
164 	dev->functionality =
165 		I2C_FUNC_I2C |
166 		I2C_FUNC_10BIT_ADDR |
167 		I2C_FUNC_SMBUS_BYTE |
168 		I2C_FUNC_SMBUS_BYTE_DATA |
169 		I2C_FUNC_SMBUS_WORD_DATA |
170 		I2C_FUNC_SMBUS_I2C_BLOCK;
171 	dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
172 		DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
173 
174 	/* Try first if we can configure the device from ACPI */
175 	r = dw_i2c_acpi_configure(pdev);
176 	if (r) {
177 		u32 param1 = i2c_dw_read_comp_param(dev);
178 
179 		dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
180 		dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
181 		dev->adapter.nr = pdev->id;
182 	}
183 	r = i2c_dw_init(dev);
184 	if (r)
185 		return r;
186 
187 	i2c_dw_disable_int(dev);
188 	r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
189 			pdev->name, dev);
190 	if (r) {
191 		dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
192 		return r;
193 	}
194 
195 	adap = &dev->adapter;
196 	i2c_set_adapdata(adap, dev);
197 	adap->owner = THIS_MODULE;
198 	adap->class = I2C_CLASS_HWMON;
199 	strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
200 			sizeof(adap->name));
201 	adap->algo = &i2c_dw_algo;
202 	adap->dev.parent = &pdev->dev;
203 	adap->dev.of_node = pdev->dev.of_node;
204 
205 	r = i2c_add_numbered_adapter(adap);
206 	if (r) {
207 		dev_err(&pdev->dev, "failure adding adapter\n");
208 		return r;
209 	}
210 
211 	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
212 	pm_runtime_use_autosuspend(&pdev->dev);
213 	pm_runtime_set_active(&pdev->dev);
214 	pm_runtime_enable(&pdev->dev);
215 
216 	return 0;
217 }
218 
219 static int dw_i2c_remove(struct platform_device *pdev)
220 {
221 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
222 
223 	pm_runtime_get_sync(&pdev->dev);
224 
225 	i2c_del_adapter(&dev->adapter);
226 
227 	i2c_dw_disable(dev);
228 
229 	pm_runtime_put(&pdev->dev);
230 	pm_runtime_disable(&pdev->dev);
231 
232 	return 0;
233 }
234 
235 #ifdef CONFIG_OF
236 static const struct of_device_id dw_i2c_of_match[] = {
237 	{ .compatible = "snps,designware-i2c", },
238 	{},
239 };
240 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
241 #endif
242 
243 #ifdef CONFIG_PM_SLEEP
244 static int dw_i2c_suspend(struct device *dev)
245 {
246 	struct platform_device *pdev = to_platform_device(dev);
247 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
248 
249 	clk_disable_unprepare(i_dev->clk);
250 
251 	return 0;
252 }
253 
254 static int dw_i2c_resume(struct device *dev)
255 {
256 	struct platform_device *pdev = to_platform_device(dev);
257 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
258 
259 	clk_prepare_enable(i_dev->clk);
260 	i2c_dw_init(i_dev);
261 
262 	return 0;
263 }
264 
265 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
266 #define DW_I2C_DEV_PM_OPS	(&dw_i2c_dev_pm_ops)
267 #else
268 #define DW_I2C_DEV_PM_OPS	NULL
269 #endif
270 
271 /* work with hotplug and coldplug */
272 MODULE_ALIAS("platform:i2c_designware");
273 
274 static struct platform_driver dw_i2c_driver = {
275 	.probe = dw_i2c_probe,
276 	.remove = dw_i2c_remove,
277 	.driver		= {
278 		.name	= "i2c_designware",
279 		.owner	= THIS_MODULE,
280 		.of_match_table = of_match_ptr(dw_i2c_of_match),
281 		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
282 		.pm	= DW_I2C_DEV_PM_OPS,
283 	},
284 };
285 
286 static int __init dw_i2c_init_driver(void)
287 {
288 	return platform_driver_register(&dw_i2c_driver);
289 }
290 subsys_initcall(dw_i2c_init_driver);
291 
292 static void __exit dw_i2c_exit_driver(void)
293 {
294 	platform_driver_unregister(&dw_i2c_driver);
295 }
296 module_exit(dw_i2c_exit_driver);
297 
298 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
299 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
300 MODULE_LICENSE("GPL");
301