xref: /linux/drivers/gpu/drm/gma500/oaktrail_hdmi_i2c.c (revision fab183d632628381b466a41479489541ac0e29a0)
1 /*
2  * Copyright © 2010 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21  * DEALINGS IN THE SOFTWARE.
22  *
23  * Authors:
24  *	Li Peng <peng.li@intel.com>
25  */
26 
27 #include <linux/export.h>
28 #include <linux/mutex.h>
29 #include <linux/pci.h>
30 #include <linux/i2c.h>
31 #include <linux/interrupt.h>
32 #include <linux/delay.h>
33 
34 #include <drm/drm_print.h>
35 
36 #include "psb_drv.h"
37 
38 #define HDMI_READ(reg)		readl(hdmi_dev->regs + (reg))
39 #define HDMI_WRITE(reg, val)	writel(val, hdmi_dev->regs + (reg))
40 
41 #define HDMI_HCR	0x1000
42 #define HCR_DETECT_HDP		(1 << 6)
43 #define HCR_ENABLE_HDCP		(1 << 5)
44 #define HCR_ENABLE_AUDIO	(1 << 2)
45 #define HCR_ENABLE_PIXEL	(1 << 1)
46 #define HCR_ENABLE_TMDS		(1 << 0)
47 #define HDMI_HICR	0x1004
48 #define HDMI_INTR_I2C_ERROR	(1 << 4)
49 #define HDMI_INTR_I2C_FULL	(1 << 3)
50 #define HDMI_INTR_I2C_DONE	(1 << 2)
51 #define HDMI_INTR_HPD		(1 << 0)
52 #define HDMI_HSR	0x1008
53 #define HDMI_HISR	0x100C
54 #define HDMI_HI2CRDB0	0x1200
55 #define HDMI_HI2CHCR	0x1240
56 #define HI2C_HDCP_WRITE		(0 << 2)
57 #define HI2C_HDCP_RI_READ	(1 << 2)
58 #define HI2C_HDCP_READ		(2 << 2)
59 #define HI2C_EDID_READ		(3 << 2)
60 #define HI2C_READ_CONTINUE	(1 << 1)
61 #define HI2C_ENABLE_TRANSACTION	(1 << 0)
62 
63 #define HDMI_ICRH	0x1100
64 #define HDMI_HI2CTDR0	0x1244
65 #define HDMI_HI2CTDR1	0x1248
66 
67 #define I2C_STAT_INIT		0
68 #define I2C_READ_DONE		1
69 #define I2C_TRANSACTION_DONE	2
70 
71 struct hdmi_i2c_dev {
72 	struct i2c_adapter *adap;
73 	struct mutex i2c_lock;
74 	struct completion complete;
75 	int status;
76 	struct i2c_msg *msg;
77 	int buf_offset;
78 };
79 
hdmi_i2c_irq_enable(struct oaktrail_hdmi_dev * hdmi_dev)80 static void hdmi_i2c_irq_enable(struct oaktrail_hdmi_dev *hdmi_dev)
81 {
82 	u32 temp;
83 
84 	temp = HDMI_READ(HDMI_HICR);
85 	temp |= (HDMI_INTR_I2C_ERROR | HDMI_INTR_I2C_FULL | HDMI_INTR_I2C_DONE);
86 	HDMI_WRITE(HDMI_HICR, temp);
87 	HDMI_READ(HDMI_HICR);
88 }
89 
hdmi_i2c_irq_disable(struct oaktrail_hdmi_dev * hdmi_dev)90 static void hdmi_i2c_irq_disable(struct oaktrail_hdmi_dev *hdmi_dev)
91 {
92 	HDMI_WRITE(HDMI_HICR, 0x0);
93 	HDMI_READ(HDMI_HICR);
94 }
95 
xfer_read(struct i2c_adapter * adap,struct i2c_msg * pmsg)96 static int xfer_read(struct i2c_adapter *adap, struct i2c_msg *pmsg)
97 {
98 	struct oaktrail_hdmi_dev *hdmi_dev = i2c_get_adapdata(adap);
99 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
100 	u32 temp;
101 	int ret;
102 
103 	i2c_dev->status = I2C_STAT_INIT;
104 	i2c_dev->msg = pmsg;
105 	i2c_dev->buf_offset = 0;
106 	reinit_completion(&i2c_dev->complete);
107 
108 	/* Enable I2C transaction */
109 	temp = ((pmsg->len) << 20) | HI2C_EDID_READ | HI2C_ENABLE_TRANSACTION;
110 	HDMI_WRITE(HDMI_HI2CHCR, temp);
111 	HDMI_READ(HDMI_HI2CHCR);
112 
113 	while (i2c_dev->status != I2C_TRANSACTION_DONE) {
114 		ret = wait_for_completion_interruptible_timeout(&i2c_dev->complete,
115 								10 * HZ);
116 		if (ret < 0)
117 			return ret;
118 		if (!ret)
119 			return -ETIMEDOUT;
120 	}
121 
122 	return 0;
123 }
124 
xfer_write(struct i2c_adapter * adap,struct i2c_msg * pmsg)125 static int xfer_write(struct i2c_adapter *adap, struct i2c_msg *pmsg)
126 {
127 	/*
128 	 * XXX: i2c write seems isn't useful for EDID probe, don't do anything
129 	 */
130 	return 0;
131 }
132 
oaktrail_hdmi_i2c_access(struct i2c_adapter * adap,struct i2c_msg * pmsg,int num)133 static int oaktrail_hdmi_i2c_access(struct i2c_adapter *adap,
134 				struct i2c_msg *pmsg,
135 				int num)
136 {
137 	struct oaktrail_hdmi_dev *hdmi_dev = i2c_get_adapdata(adap);
138 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
139 	int i, ret = 0;
140 
141 	mutex_lock(&i2c_dev->i2c_lock);
142 
143 	/* Enable i2c unit */
144 	HDMI_WRITE(HDMI_ICRH, 0x00008760);
145 
146 	/* Enable irq */
147 	hdmi_i2c_irq_enable(hdmi_dev);
148 	for (i = 0; i < num; i++) {
149 		if (pmsg->len && pmsg->buf) {
150 			if (pmsg->flags & I2C_M_RD)
151 				ret = xfer_read(adap, pmsg);
152 			else
153 				ret = xfer_write(adap, pmsg);
154 			if (ret)
155 				break;
156 		}
157 		pmsg++;         /* next message */
158 	}
159 
160 	/* Disable irq */
161 	hdmi_i2c_irq_disable(hdmi_dev);
162 
163 	mutex_unlock(&i2c_dev->i2c_lock);
164 
165 	if (ret)
166 		return ret;
167 
168 	return i;
169 }
170 
oaktrail_hdmi_i2c_func(struct i2c_adapter * adapter)171 static u32 oaktrail_hdmi_i2c_func(struct i2c_adapter *adapter)
172 {
173 	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
174 }
175 
176 static const struct i2c_algorithm oaktrail_hdmi_i2c_algorithm = {
177 	.master_xfer	= oaktrail_hdmi_i2c_access,
178 	.functionality  = oaktrail_hdmi_i2c_func,
179 };
180 
181 static struct i2c_adapter oaktrail_hdmi_i2c_adapter = {
182 	.name		= "oaktrail_hdmi_i2c",
183 	.nr		= 3,
184 	.owner		= THIS_MODULE,
185 	.algo		= &oaktrail_hdmi_i2c_algorithm,
186 };
187 
hdmi_i2c_read(struct oaktrail_hdmi_dev * hdmi_dev)188 static void hdmi_i2c_read(struct oaktrail_hdmi_dev *hdmi_dev)
189 {
190 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
191 	struct i2c_msg *msg = i2c_dev->msg;
192 	u8 *buf = msg->buf;
193 	u32 temp;
194 	int i, offset;
195 
196 	offset = i2c_dev->buf_offset;
197 	for (i = 0; i < 0x10; i++) {
198 		temp = HDMI_READ(HDMI_HI2CRDB0 + (i * 4));
199 		memcpy(buf + (offset + i * 4), &temp, 4);
200 	}
201 	i2c_dev->buf_offset += (0x10 * 4);
202 
203 	/* clearing read buffer full intr */
204 	temp = HDMI_READ(HDMI_HISR);
205 	HDMI_WRITE(HDMI_HISR, temp | HDMI_INTR_I2C_FULL);
206 	HDMI_READ(HDMI_HISR);
207 
208 	/* continue read transaction */
209 	temp = HDMI_READ(HDMI_HI2CHCR);
210 	HDMI_WRITE(HDMI_HI2CHCR, temp | HI2C_READ_CONTINUE);
211 	HDMI_READ(HDMI_HI2CHCR);
212 
213 	i2c_dev->status = I2C_READ_DONE;
214 	return;
215 }
216 
hdmi_i2c_transaction_done(struct oaktrail_hdmi_dev * hdmi_dev)217 static void hdmi_i2c_transaction_done(struct oaktrail_hdmi_dev *hdmi_dev)
218 {
219 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
220 	u32 temp;
221 
222 	/* clear transaction done intr */
223 	temp = HDMI_READ(HDMI_HISR);
224 	HDMI_WRITE(HDMI_HISR, temp | HDMI_INTR_I2C_DONE);
225 	HDMI_READ(HDMI_HISR);
226 
227 
228 	temp = HDMI_READ(HDMI_HI2CHCR);
229 	HDMI_WRITE(HDMI_HI2CHCR, temp & ~HI2C_ENABLE_TRANSACTION);
230 	HDMI_READ(HDMI_HI2CHCR);
231 
232 	i2c_dev->status = I2C_TRANSACTION_DONE;
233 	return;
234 }
235 
oaktrail_hdmi_i2c_handler(int this_irq,void * dev)236 static irqreturn_t oaktrail_hdmi_i2c_handler(int this_irq, void *dev)
237 {
238 	struct oaktrail_hdmi_dev *hdmi_dev = dev;
239 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
240 	u32 stat;
241 
242 	stat = HDMI_READ(HDMI_HISR);
243 
244 	if (stat & HDMI_INTR_HPD) {
245 		HDMI_WRITE(HDMI_HISR, stat | HDMI_INTR_HPD);
246 		HDMI_READ(HDMI_HISR);
247 	}
248 
249 	if (stat & HDMI_INTR_I2C_FULL)
250 		hdmi_i2c_read(hdmi_dev);
251 
252 	if (stat & HDMI_INTR_I2C_DONE)
253 		hdmi_i2c_transaction_done(hdmi_dev);
254 
255 	complete(&i2c_dev->complete);
256 
257 	return IRQ_HANDLED;
258 }
259 
260 /*
261  * choose alternate function 2 of GPIO pin 52, 53,
262  * which is used by HDMI I2C logic
263  */
oaktrail_hdmi_i2c_gpio_fix(void)264 static void oaktrail_hdmi_i2c_gpio_fix(void)
265 {
266 	void __iomem *base;
267 	unsigned int gpio_base = 0xff12c000;
268 	int gpio_len = 0x1000;
269 	u32 temp;
270 
271 	base = ioremap((resource_size_t)gpio_base, gpio_len);
272 	if (base == NULL) {
273 		DRM_ERROR("gpio ioremap fail\n");
274 		return;
275 	}
276 
277 	temp = readl(base + 0x44);
278 	DRM_DEBUG_DRIVER("old gpio val %x\n", temp);
279 	writel((temp | 0x00000a00), (base +  0x44));
280 	temp = readl(base + 0x44);
281 	DRM_DEBUG_DRIVER("new gpio val %x\n", temp);
282 
283 	iounmap(base);
284 }
285 
oaktrail_hdmi_i2c_init(struct pci_dev * dev)286 int oaktrail_hdmi_i2c_init(struct pci_dev *dev)
287 {
288 	struct oaktrail_hdmi_dev *hdmi_dev;
289 	struct hdmi_i2c_dev *i2c_dev;
290 	int ret;
291 
292 	hdmi_dev = pci_get_drvdata(dev);
293 
294 	i2c_dev = kzalloc_obj(struct hdmi_i2c_dev);
295 	if (!i2c_dev)
296 		return -ENOMEM;
297 
298 	i2c_dev->adap = &oaktrail_hdmi_i2c_adapter;
299 	i2c_dev->status = I2C_STAT_INIT;
300 	init_completion(&i2c_dev->complete);
301 	mutex_init(&i2c_dev->i2c_lock);
302 	i2c_set_adapdata(&oaktrail_hdmi_i2c_adapter, hdmi_dev);
303 	hdmi_dev->i2c_dev = i2c_dev;
304 
305 	/* Enable HDMI I2C function on gpio */
306 	oaktrail_hdmi_i2c_gpio_fix();
307 
308 	/* request irq */
309 	ret = request_irq(dev->irq, oaktrail_hdmi_i2c_handler, IRQF_SHARED,
310 			  oaktrail_hdmi_i2c_adapter.name, hdmi_dev);
311 	if (ret) {
312 		DRM_ERROR("Failed to request IRQ for I2C controller\n");
313 		goto free_dev;
314 	}
315 
316 	/* Adapter registration */
317 	ret = i2c_add_numbered_adapter(&oaktrail_hdmi_i2c_adapter);
318 	if (ret) {
319 		DRM_ERROR("Failed to add I2C adapter\n");
320 		goto free_irq;
321 	}
322 
323 	return 0;
324 
325 free_irq:
326 	free_irq(dev->irq, hdmi_dev);
327 free_dev:
328 	kfree(i2c_dev);
329 
330 	return ret;
331 }
332 
oaktrail_hdmi_i2c_exit(struct pci_dev * dev)333 void oaktrail_hdmi_i2c_exit(struct pci_dev *dev)
334 {
335 	struct oaktrail_hdmi_dev *hdmi_dev;
336 	struct hdmi_i2c_dev *i2c_dev;
337 
338 	hdmi_dev = pci_get_drvdata(dev);
339 	i2c_del_adapter(&oaktrail_hdmi_i2c_adapter);
340 
341 	i2c_dev = hdmi_dev->i2c_dev;
342 	kfree(i2c_dev);
343 	free_irq(dev->irq, hdmi_dev);
344 }
345