xref: /linux/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 /*
2  * Copyright 2007-8 Advanced Micro Devices, Inc.
3  * Copyright 2008 Red Hat Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  *
23  * Authors: Dave Airlie
24  *          Alex Deucher
25  */
26 
27 #include <linux/pci.h>
28 
29 #include <drm/drm_edid.h>
30 #include <drm/amdgpu_drm.h>
31 #include "amdgpu.h"
32 #include "amdgpu_i2c.h"
33 #include "amdgpu_atombios.h"
34 #include "atom.h"
35 #include "atombios_dp.h"
36 #include "atombios_i2c.h"
37 
38 /* bit banging i2c */
39 static int amdgpu_i2c_pre_xfer(struct i2c_adapter *i2c_adap)
40 {
41 	struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
42 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
43 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
44 	uint32_t temp;
45 
46 	mutex_lock(&i2c->mutex);
47 
48 	/* switch the pads to ddc mode */
49 	if (rec->hw_capable) {
50 		temp = RREG32(rec->mask_clk_reg);
51 		temp &= ~(1 << 16);
52 		WREG32(rec->mask_clk_reg, temp);
53 	}
54 
55 	/* clear the output pin values */
56 	temp = RREG32(rec->a_clk_reg) & ~rec->a_clk_mask;
57 	WREG32(rec->a_clk_reg, temp);
58 
59 	temp = RREG32(rec->a_data_reg) & ~rec->a_data_mask;
60 	WREG32(rec->a_data_reg, temp);
61 
62 	/* set the pins to input */
63 	temp = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
64 	WREG32(rec->en_clk_reg, temp);
65 
66 	temp = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
67 	WREG32(rec->en_data_reg, temp);
68 
69 	/* mask the gpio pins for software use */
70 	temp = RREG32(rec->mask_clk_reg) | rec->mask_clk_mask;
71 	WREG32(rec->mask_clk_reg, temp);
72 	temp = RREG32(rec->mask_clk_reg);
73 
74 	temp = RREG32(rec->mask_data_reg) | rec->mask_data_mask;
75 	WREG32(rec->mask_data_reg, temp);
76 	temp = RREG32(rec->mask_data_reg);
77 
78 	return 0;
79 }
80 
81 static void amdgpu_i2c_post_xfer(struct i2c_adapter *i2c_adap)
82 {
83 	struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
84 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
85 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
86 	uint32_t temp;
87 
88 	/* unmask the gpio pins for software use */
89 	temp = RREG32(rec->mask_clk_reg) & ~rec->mask_clk_mask;
90 	WREG32(rec->mask_clk_reg, temp);
91 	temp = RREG32(rec->mask_clk_reg);
92 
93 	temp = RREG32(rec->mask_data_reg) & ~rec->mask_data_mask;
94 	WREG32(rec->mask_data_reg, temp);
95 	temp = RREG32(rec->mask_data_reg);
96 
97 	mutex_unlock(&i2c->mutex);
98 }
99 
100 static int amdgpu_i2c_get_clock(void *i2c_priv)
101 {
102 	struct amdgpu_i2c_chan *i2c = i2c_priv;
103 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
104 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
105 	uint32_t val;
106 
107 	/* read the value off the pin */
108 	val = RREG32(rec->y_clk_reg);
109 	val &= rec->y_clk_mask;
110 
111 	return (val != 0);
112 }
113 
114 
115 static int amdgpu_i2c_get_data(void *i2c_priv)
116 {
117 	struct amdgpu_i2c_chan *i2c = i2c_priv;
118 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
119 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
120 	uint32_t val;
121 
122 	/* read the value off the pin */
123 	val = RREG32(rec->y_data_reg);
124 	val &= rec->y_data_mask;
125 
126 	return (val != 0);
127 }
128 
129 static void amdgpu_i2c_set_clock(void *i2c_priv, int clock)
130 {
131 	struct amdgpu_i2c_chan *i2c = i2c_priv;
132 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
133 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
134 	uint32_t val;
135 
136 	/* set pin direction */
137 	val = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
138 	val |= clock ? 0 : rec->en_clk_mask;
139 	WREG32(rec->en_clk_reg, val);
140 }
141 
142 static void amdgpu_i2c_set_data(void *i2c_priv, int data)
143 {
144 	struct amdgpu_i2c_chan *i2c = i2c_priv;
145 	struct amdgpu_device *adev = drm_to_adev(i2c->dev);
146 	struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
147 	uint32_t val;
148 
149 	/* set pin direction */
150 	val = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
151 	val |= data ? 0 : rec->en_data_mask;
152 	WREG32(rec->en_data_reg, val);
153 }
154 
155 static const struct i2c_algorithm amdgpu_atombios_i2c_algo = {
156 	.master_xfer = amdgpu_atombios_i2c_xfer,
157 	.functionality = amdgpu_atombios_i2c_func,
158 };
159 
160 struct amdgpu_i2c_chan *amdgpu_i2c_create(struct drm_device *dev,
161 					  const struct amdgpu_i2c_bus_rec *rec,
162 					  const char *name)
163 {
164 	struct amdgpu_i2c_chan *i2c;
165 	int ret;
166 
167 	/* don't add the mm_i2c bus unless hw_i2c is enabled */
168 	if (rec->mm_i2c && (amdgpu_hw_i2c == 0))
169 		return NULL;
170 
171 	i2c = kzalloc(sizeof(struct amdgpu_i2c_chan), GFP_KERNEL);
172 	if (i2c == NULL)
173 		return NULL;
174 
175 	i2c->rec = *rec;
176 	i2c->adapter.owner = THIS_MODULE;
177 	i2c->adapter.dev.parent = dev->dev;
178 	i2c->dev = dev;
179 	i2c_set_adapdata(&i2c->adapter, i2c);
180 	mutex_init(&i2c->mutex);
181 	if (rec->hw_capable &&
182 	    amdgpu_hw_i2c) {
183 		/* hw i2c using atom */
184 		snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
185 			 "AMDGPU i2c hw bus %s", name);
186 		i2c->adapter.algo = &amdgpu_atombios_i2c_algo;
187 		ret = devm_i2c_add_adapter(dev->dev, &i2c->adapter);
188 		if (ret)
189 			goto out_free;
190 	} else {
191 		/* set the amdgpu bit adapter */
192 		snprintf(i2c->adapter.name, sizeof(i2c->adapter.name),
193 			 "AMDGPU i2c bit bus %s", name);
194 		i2c->adapter.algo_data = &i2c->bit;
195 		i2c->bit.pre_xfer = amdgpu_i2c_pre_xfer;
196 		i2c->bit.post_xfer = amdgpu_i2c_post_xfer;
197 		i2c->bit.setsda = amdgpu_i2c_set_data;
198 		i2c->bit.setscl = amdgpu_i2c_set_clock;
199 		i2c->bit.getsda = amdgpu_i2c_get_data;
200 		i2c->bit.getscl = amdgpu_i2c_get_clock;
201 		i2c->bit.udelay = 10;
202 		i2c->bit.timeout = usecs_to_jiffies(2200);	/* from VESA */
203 		i2c->bit.data = i2c;
204 		ret = i2c_bit_add_bus(&i2c->adapter);
205 		if (ret) {
206 			DRM_ERROR("Failed to register bit i2c %s\n", name);
207 			goto out_free;
208 		}
209 	}
210 
211 	return i2c;
212 out_free:
213 	kfree(i2c);
214 	return NULL;
215 
216 }
217 
218 void amdgpu_i2c_init(struct amdgpu_device *adev)
219 {
220 	if (!adev->is_atom_fw) {
221 		if (!amdgpu_device_has_dc_support(adev)) {
222 			amdgpu_atombios_i2c_init(adev);
223 		} else {
224 			switch (adev->asic_type) {
225 			case CHIP_POLARIS10:
226 			case CHIP_POLARIS11:
227 			case CHIP_POLARIS12:
228 				amdgpu_atombios_oem_i2c_init(adev, 0x97);
229 				break;
230 			default:
231 				break;
232 			}
233 		}
234 	}
235 }
236 
237 /* remove all the buses */
238 void amdgpu_i2c_fini(struct amdgpu_device *adev)
239 {
240 	int i;
241 
242 	for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++)
243 		if (adev->i2c_bus[i])
244 			adev->i2c_bus[i] = NULL;
245 }
246 
247 /* looks up bus based on id */
248 struct amdgpu_i2c_chan *
249 amdgpu_i2c_lookup(struct amdgpu_device *adev,
250 		  const struct amdgpu_i2c_bus_rec *i2c_bus)
251 {
252 	int i;
253 
254 	for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
255 		if (adev->i2c_bus[i] &&
256 		    (adev->i2c_bus[i]->rec.i2c_id == i2c_bus->i2c_id)) {
257 			return adev->i2c_bus[i];
258 		}
259 	}
260 	return NULL;
261 }
262 
263 static int amdgpu_i2c_get_byte(struct amdgpu_i2c_chan *i2c_bus,
264 				 u8 slave_addr,
265 				 u8 addr,
266 				 u8 *val)
267 {
268 	u8 out_buf[2];
269 	u8 in_buf[2];
270 	struct i2c_msg msgs[] = {
271 		{
272 			.addr = slave_addr,
273 			.flags = 0,
274 			.len = 1,
275 			.buf = out_buf,
276 		},
277 		{
278 			.addr = slave_addr,
279 			.flags = I2C_M_RD,
280 			.len = 1,
281 			.buf = in_buf,
282 		}
283 	};
284 
285 	out_buf[0] = addr;
286 	out_buf[1] = 0;
287 
288 	if (i2c_transfer(&i2c_bus->adapter, msgs, 2) != 2) {
289 		DRM_DEBUG("i2c 0x%02x read failed\n", addr);
290 		return -EIO;
291 	}
292 
293 	*val = in_buf[0];
294 	DRM_DEBUG("val = 0x%02x\n", *val);
295 
296 	return 0;
297 }
298 
299 static int amdgpu_i2c_put_byte(struct amdgpu_i2c_chan *i2c_bus,
300 				 u8 slave_addr,
301 				 u8 addr,
302 				 u8 val)
303 {
304 	uint8_t out_buf[2];
305 	struct i2c_msg msg = {
306 		.addr = slave_addr,
307 		.flags = 0,
308 		.len = 2,
309 		.buf = out_buf,
310 	};
311 
312 	out_buf[0] = addr;
313 	out_buf[1] = val;
314 
315 	if (i2c_transfer(&i2c_bus->adapter, &msg, 1) != 1) {
316 		DRM_DEBUG("i2c 0x%02x 0x%02x write failed\n", addr, val);
317 		return -EIO;
318 	}
319 
320 	return 0;
321 }
322 
323 /* ddc router switching */
324 void
325 amdgpu_i2c_router_select_ddc_port(const struct amdgpu_connector *amdgpu_connector)
326 {
327 	u8 val = 0;
328 
329 	if (!amdgpu_connector->router.ddc_valid)
330 		return;
331 
332 	if (!amdgpu_connector->router_bus)
333 		return;
334 
335 	if (amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
336 			    amdgpu_connector->router.i2c_addr,
337 			    0x3, &val))
338 		return;
339 	val &= ~amdgpu_connector->router.ddc_mux_control_pin;
340 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
341 			    amdgpu_connector->router.i2c_addr,
342 			    0x3, val);
343 	if (amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
344 			    amdgpu_connector->router.i2c_addr,
345 			    0x1, &val))
346 		return;
347 	val &= ~amdgpu_connector->router.ddc_mux_control_pin;
348 	val |= amdgpu_connector->router.ddc_mux_state;
349 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
350 			    amdgpu_connector->router.i2c_addr,
351 			    0x1, val);
352 }
353 
354 /* clock/data router switching */
355 void
356 amdgpu_i2c_router_select_cd_port(const struct amdgpu_connector *amdgpu_connector)
357 {
358 	u8 val;
359 
360 	if (!amdgpu_connector->router.cd_valid)
361 		return;
362 
363 	if (!amdgpu_connector->router_bus)
364 		return;
365 
366 	if (amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
367 			    amdgpu_connector->router.i2c_addr,
368 			    0x3, &val))
369 		return;
370 	val &= ~amdgpu_connector->router.cd_mux_control_pin;
371 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
372 			    amdgpu_connector->router.i2c_addr,
373 			    0x3, val);
374 	if (amdgpu_i2c_get_byte(amdgpu_connector->router_bus,
375 			    amdgpu_connector->router.i2c_addr,
376 			    0x1, &val))
377 		return;
378 	val &= ~amdgpu_connector->router.cd_mux_control_pin;
379 	val |= amdgpu_connector->router.cd_mux_state;
380 	amdgpu_i2c_put_byte(amdgpu_connector->router_bus,
381 			    amdgpu_connector->router.i2c_addr,
382 			    0x1, val);
383 }
384