xref: /linux/drivers/gpu/drm/gma500/oaktrail_hdmi_i2c.c (revision f6e8dc9edf963dbc99085e54f6ced6da9daa6100)
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 
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 
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 
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 
102 	i2c_dev->status = I2C_STAT_INIT;
103 	i2c_dev->msg = pmsg;
104 	i2c_dev->buf_offset = 0;
105 	reinit_completion(&i2c_dev->complete);
106 
107 	/* Enable I2C transaction */
108 	temp = ((pmsg->len) << 20) | HI2C_EDID_READ | HI2C_ENABLE_TRANSACTION;
109 	HDMI_WRITE(HDMI_HI2CHCR, temp);
110 	HDMI_READ(HDMI_HI2CHCR);
111 
112 	while (i2c_dev->status != I2C_TRANSACTION_DONE)
113 		wait_for_completion_interruptible_timeout(&i2c_dev->complete,
114 								10 * HZ);
115 
116 	return 0;
117 }
118 
119 static int xfer_write(struct i2c_adapter *adap, struct i2c_msg *pmsg)
120 {
121 	/*
122 	 * XXX: i2c write seems isn't useful for EDID probe, don't do anything
123 	 */
124 	return 0;
125 }
126 
127 static int oaktrail_hdmi_i2c_access(struct i2c_adapter *adap,
128 				struct i2c_msg *pmsg,
129 				int num)
130 {
131 	struct oaktrail_hdmi_dev *hdmi_dev = i2c_get_adapdata(adap);
132 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
133 	int i;
134 
135 	mutex_lock(&i2c_dev->i2c_lock);
136 
137 	/* Enable i2c unit */
138 	HDMI_WRITE(HDMI_ICRH, 0x00008760);
139 
140 	/* Enable irq */
141 	hdmi_i2c_irq_enable(hdmi_dev);
142 	for (i = 0; i < num; i++) {
143 		if (pmsg->len && pmsg->buf) {
144 			if (pmsg->flags & I2C_M_RD)
145 				xfer_read(adap, pmsg);
146 			else
147 				xfer_write(adap, pmsg);
148 		}
149 		pmsg++;         /* next message */
150 	}
151 
152 	/* Disable irq */
153 	hdmi_i2c_irq_disable(hdmi_dev);
154 
155 	mutex_unlock(&i2c_dev->i2c_lock);
156 
157 	return i;
158 }
159 
160 static u32 oaktrail_hdmi_i2c_func(struct i2c_adapter *adapter)
161 {
162 	return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
163 }
164 
165 static const struct i2c_algorithm oaktrail_hdmi_i2c_algorithm = {
166 	.master_xfer	= oaktrail_hdmi_i2c_access,
167 	.functionality  = oaktrail_hdmi_i2c_func,
168 };
169 
170 static struct i2c_adapter oaktrail_hdmi_i2c_adapter = {
171 	.name		= "oaktrail_hdmi_i2c",
172 	.nr		= 3,
173 	.owner		= THIS_MODULE,
174 	.algo		= &oaktrail_hdmi_i2c_algorithm,
175 };
176 
177 static void hdmi_i2c_read(struct oaktrail_hdmi_dev *hdmi_dev)
178 {
179 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
180 	struct i2c_msg *msg = i2c_dev->msg;
181 	u8 *buf = msg->buf;
182 	u32 temp;
183 	int i, offset;
184 
185 	offset = i2c_dev->buf_offset;
186 	for (i = 0; i < 0x10; i++) {
187 		temp = HDMI_READ(HDMI_HI2CRDB0 + (i * 4));
188 		memcpy(buf + (offset + i * 4), &temp, 4);
189 	}
190 	i2c_dev->buf_offset += (0x10 * 4);
191 
192 	/* clearing read buffer full intr */
193 	temp = HDMI_READ(HDMI_HISR);
194 	HDMI_WRITE(HDMI_HISR, temp | HDMI_INTR_I2C_FULL);
195 	HDMI_READ(HDMI_HISR);
196 
197 	/* continue read transaction */
198 	temp = HDMI_READ(HDMI_HI2CHCR);
199 	HDMI_WRITE(HDMI_HI2CHCR, temp | HI2C_READ_CONTINUE);
200 	HDMI_READ(HDMI_HI2CHCR);
201 
202 	i2c_dev->status = I2C_READ_DONE;
203 	return;
204 }
205 
206 static void hdmi_i2c_transaction_done(struct oaktrail_hdmi_dev *hdmi_dev)
207 {
208 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
209 	u32 temp;
210 
211 	/* clear transaction done intr */
212 	temp = HDMI_READ(HDMI_HISR);
213 	HDMI_WRITE(HDMI_HISR, temp | HDMI_INTR_I2C_DONE);
214 	HDMI_READ(HDMI_HISR);
215 
216 
217 	temp = HDMI_READ(HDMI_HI2CHCR);
218 	HDMI_WRITE(HDMI_HI2CHCR, temp & ~HI2C_ENABLE_TRANSACTION);
219 	HDMI_READ(HDMI_HI2CHCR);
220 
221 	i2c_dev->status = I2C_TRANSACTION_DONE;
222 	return;
223 }
224 
225 static irqreturn_t oaktrail_hdmi_i2c_handler(int this_irq, void *dev)
226 {
227 	struct oaktrail_hdmi_dev *hdmi_dev = dev;
228 	struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
229 	u32 stat;
230 
231 	stat = HDMI_READ(HDMI_HISR);
232 
233 	if (stat & HDMI_INTR_HPD) {
234 		HDMI_WRITE(HDMI_HISR, stat | HDMI_INTR_HPD);
235 		HDMI_READ(HDMI_HISR);
236 	}
237 
238 	if (stat & HDMI_INTR_I2C_FULL)
239 		hdmi_i2c_read(hdmi_dev);
240 
241 	if (stat & HDMI_INTR_I2C_DONE)
242 		hdmi_i2c_transaction_done(hdmi_dev);
243 
244 	complete(&i2c_dev->complete);
245 
246 	return IRQ_HANDLED;
247 }
248 
249 /*
250  * choose alternate function 2 of GPIO pin 52, 53,
251  * which is used by HDMI I2C logic
252  */
253 static void oaktrail_hdmi_i2c_gpio_fix(void)
254 {
255 	void __iomem *base;
256 	unsigned int gpio_base = 0xff12c000;
257 	int gpio_len = 0x1000;
258 	u32 temp;
259 
260 	base = ioremap((resource_size_t)gpio_base, gpio_len);
261 	if (base == NULL) {
262 		DRM_ERROR("gpio ioremap fail\n");
263 		return;
264 	}
265 
266 	temp = readl(base + 0x44);
267 	DRM_DEBUG_DRIVER("old gpio val %x\n", temp);
268 	writel((temp | 0x00000a00), (base +  0x44));
269 	temp = readl(base + 0x44);
270 	DRM_DEBUG_DRIVER("new gpio val %x\n", temp);
271 
272 	iounmap(base);
273 }
274 
275 int oaktrail_hdmi_i2c_init(struct pci_dev *dev)
276 {
277 	struct oaktrail_hdmi_dev *hdmi_dev;
278 	struct hdmi_i2c_dev *i2c_dev;
279 	int ret;
280 
281 	hdmi_dev = pci_get_drvdata(dev);
282 
283 	i2c_dev = kzalloc(sizeof(struct hdmi_i2c_dev), GFP_KERNEL);
284 	if (!i2c_dev)
285 		return -ENOMEM;
286 
287 	i2c_dev->adap = &oaktrail_hdmi_i2c_adapter;
288 	i2c_dev->status = I2C_STAT_INIT;
289 	init_completion(&i2c_dev->complete);
290 	mutex_init(&i2c_dev->i2c_lock);
291 	i2c_set_adapdata(&oaktrail_hdmi_i2c_adapter, hdmi_dev);
292 	hdmi_dev->i2c_dev = i2c_dev;
293 
294 	/* Enable HDMI I2C function on gpio */
295 	oaktrail_hdmi_i2c_gpio_fix();
296 
297 	/* request irq */
298 	ret = request_irq(dev->irq, oaktrail_hdmi_i2c_handler, IRQF_SHARED,
299 			  oaktrail_hdmi_i2c_adapter.name, hdmi_dev);
300 	if (ret) {
301 		DRM_ERROR("Failed to request IRQ for I2C controller\n");
302 		goto free_dev;
303 	}
304 
305 	/* Adapter registration */
306 	ret = i2c_add_numbered_adapter(&oaktrail_hdmi_i2c_adapter);
307 	if (ret) {
308 		DRM_ERROR("Failed to add I2C adapter\n");
309 		goto free_irq;
310 	}
311 
312 	return 0;
313 
314 free_irq:
315 	free_irq(dev->irq, hdmi_dev);
316 free_dev:
317 	kfree(i2c_dev);
318 
319 	return ret;
320 }
321 
322 void oaktrail_hdmi_i2c_exit(struct pci_dev *dev)
323 {
324 	struct oaktrail_hdmi_dev *hdmi_dev;
325 	struct hdmi_i2c_dev *i2c_dev;
326 
327 	hdmi_dev = pci_get_drvdata(dev);
328 	i2c_del_adapter(&oaktrail_hdmi_i2c_adapter);
329 
330 	i2c_dev = hdmi_dev->i2c_dev;
331 	kfree(i2c_dev);
332 	free_irq(dev->irq, hdmi_dev);
333 }
334