xref: /netbsd-src/sys/dev/pci/radeonfb_i2c.c (revision 13d4bb4cc874de96add7fc4227d38a1d656b03d1)
1 /*-
2  * Copyright (c) 2006 Itronix Inc.
3  * All rights reserved.
4  *
5  * Written by Garrett D'Amore for Itronix Inc.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of Itronix Inc. may not be used to endorse
16  *    or promote products derived from this software without specific
17  *    prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND ANY EXPRESS
20  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
25  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * ATI Technologies Inc. ("ATI") has not assisted in the creation of, and
34  * does not endorse, this software.  ATI will not be responsible or liable
35  * for any actual or alleged damage or loss caused by or in connection with
36  * the use of or reliance on this software.
37  */
38 
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: radeonfb_i2c.c,v 1.4 2022/09/25 17:52:25 thorpej Exp $");
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/device.h>
45 #include <sys/systm.h>
46 #include <sys/bus.h>
47 
48 #include <dev/i2c/i2cvar.h>
49 #include <dev/i2c/i2c_bitbang.h>
50 #include <dev/i2c/ddcvar.h>
51 
52 #include <dev/pci/radeonfbreg.h>
53 #include <dev/pci/radeonfbvar.h>
54 
55 /* i2c support */
56 static int radeonfb_i2c_acquire_bus(void *, int);
57 static void radeonfb_i2c_release_bus(void *, int);
58 static int radeonfb_i2c_send_start(void *, int);
59 static int radeonfb_i2c_send_stop(void *, int);
60 static int radeonfb_i2c_initiate_xfer(void *, i2c_addr_t, int);
61 static int radeonfb_i2c_read_byte(void *, uint8_t *, int);
62 static int radeonfb_i2c_write_byte(void *, uint8_t, int);
63 
64 /* i2c bit-bang glue */
65 static void radeonfb_i2cbb_set_bits(void *, uint32_t);
66 static void radeonfb_i2cbb_set_dir(void *, uint32_t);
67 static uint32_t radeonfb_i2cbb_read(void *);
68 
69 /*
70  * I2C bit-bang operations
71  */
72 void
radeonfb_i2cbb_set_bits(void * cookie,uint32_t bits)73 radeonfb_i2cbb_set_bits(void *cookie, uint32_t bits)
74 {
75 	struct radeonfb_i2c	*ric = (struct radeonfb_i2c *)cookie;
76 	struct radeonfb_softc	*sc = ric->ric_softc;
77 
78 	PATCH32(sc, ric->ric_register, bits,
79 	    ~(RADEON_GPIO_A_0 | RADEON_GPIO_A_1));
80 }
81 
82 void
radeonfb_i2cbb_set_dir(void * cookie,uint32_t bits)83 radeonfb_i2cbb_set_dir(void *cookie, uint32_t bits)
84 {
85 	struct radeonfb_i2c	*ric = (struct radeonfb_i2c *)cookie;
86 	struct radeonfb_softc	*sc = ric->ric_softc;
87 
88 	PATCH32(sc, ric->ric_register, bits, ~(RADEON_GPIO_EN_0));
89 }
90 
91 uint32_t
radeonfb_i2cbb_read(void * cookie)92 radeonfb_i2cbb_read(void *cookie)
93 {
94 	struct radeonfb_i2c	*ric = (struct radeonfb_i2c *)cookie;
95 	struct radeonfb_softc	*sc = ric->ric_softc;
96 
97 	/* output bit is 0 shifted, input bit is shifted 8 */
98 	return (GET32(sc, ric->ric_register) >> RADEON_GPIO_Y_SHIFT_0);
99 }
100 
101 static const struct i2c_bitbang_ops radeonfb_i2cbb_ops = {
102 	radeonfb_i2cbb_set_bits,
103 	radeonfb_i2cbb_set_dir,
104 	radeonfb_i2cbb_read,
105 	{
106 		RADEON_GPIO_A_0,	/* SDA */
107 		RADEON_GPIO_A_1,	/* SCL */
108 		RADEON_GPIO_EN_0,	/* SDA output */
109 		0,			/* SDA input */
110 	}
111 };
112 
113 /*
114  * I2C support
115  */
116 int
radeonfb_i2c_acquire_bus(void * cookie,int flags)117 radeonfb_i2c_acquire_bus(void *cookie, int flags)
118 {
119 	struct radeonfb_i2c	*ric = (struct radeonfb_i2c *)cookie;
120 	struct radeonfb_softc	*sc = ric->ric_softc;
121 	int			i;
122 
123 	/*
124 	 * Some hardware seems to have hardware/software combined access
125 	 * to the DVI I2C.  We want to use software.
126 	 */
127 	if (ric->ric_register == RADEON_GPIO_DVI_DDC) {
128 
129 		/* ask for software access to I2C bus */
130 		SET32(sc, ric->ric_register, RADEON_GPIO_SW_USE);
131 
132 		/*
133 		 * wait for the chip to give up access.  we don't make
134 		 * this a hard timeout, because some hardware might
135 		 * not implement this negotiation protocol
136 		 */
137 		for (i = RADEON_TIMEOUT; i; i--) {
138 			if (GET32(sc, ric->ric_register) & RADEON_GPIO_SW_USE)
139 				break;
140 		}
141 	}
142 
143 	/* enable the I2C clock */
144 	SET32(sc, ric->ric_register, RADEON_GPIO_EN_1);
145 
146 	return 0;
147 }
148 
149 void
radeonfb_i2c_release_bus(void * cookie,int flags)150 radeonfb_i2c_release_bus(void *cookie, int flags)
151 {
152 	struct radeonfb_i2c	*ric = (struct radeonfb_i2c *)cookie;
153 	struct radeonfb_softc	*sc = ric->ric_softc;
154 
155 	if (ric->ric_register == RADEON_GPIO_DVI_DDC) {
156 		/* we no longer "want" I2C, and we're "done" with it */
157 		CLR32(sc, ric->ric_register, RADEON_GPIO_SW_USE);
158 		SET32(sc, ric->ric_register, RADEON_GPIO_SW_DONE);
159 	}
160 }
161 
162 int
radeonfb_i2c_send_start(void * cookie,int flags)163 radeonfb_i2c_send_start(void *cookie, int flags)
164 {
165 
166 	return i2c_bitbang_send_start(cookie, flags, &radeonfb_i2cbb_ops);
167 }
168 
169 int
radeonfb_i2c_send_stop(void * cookie,int flags)170 radeonfb_i2c_send_stop(void *cookie, int flags)
171 {
172 
173 	return i2c_bitbang_send_stop(cookie, flags, &radeonfb_i2cbb_ops);
174 }
175 
176 int
radeonfb_i2c_initiate_xfer(void * cookie,i2c_addr_t addr,int flags)177 radeonfb_i2c_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
178 {
179 
180 	return i2c_bitbang_initiate_xfer(cookie, addr, flags,
181 	    &radeonfb_i2cbb_ops);
182 }
183 
184 int
radeonfb_i2c_read_byte(void * cookie,uint8_t * valp,int flags)185 radeonfb_i2c_read_byte(void *cookie, uint8_t *valp, int flags)
186 {
187 
188 	return i2c_bitbang_read_byte(cookie, valp, flags, &radeonfb_i2cbb_ops);
189 }
190 
191 int
radeonfb_i2c_write_byte(void * cookie,uint8_t val,int flags)192 radeonfb_i2c_write_byte(void *cookie, uint8_t val, int flags)
193 {
194 
195 	return i2c_bitbang_write_byte(cookie, val, flags, &radeonfb_i2cbb_ops);
196 }
197 
198 void
radeonfb_i2c_init(struct radeonfb_softc * sc)199 radeonfb_i2c_init(struct radeonfb_softc *sc)
200 {
201 	int	i;
202 
203 	for (i = 0; i < 4; i++) {
204 		struct i2c_controller	*icc = &sc->sc_i2c[i].ric_controller;
205 
206 		sc->sc_i2c[i].ric_softc = sc;
207 		iic_tag_init(icc);
208 		icc->ic_cookie = &sc->sc_i2c[i];
209 		icc->ic_acquire_bus = radeonfb_i2c_acquire_bus;
210 		icc->ic_release_bus = radeonfb_i2c_release_bus;
211 		icc->ic_send_start = radeonfb_i2c_send_start;
212 		icc->ic_send_stop = radeonfb_i2c_send_stop;
213 		icc->ic_initiate_xfer = radeonfb_i2c_initiate_xfer;
214 		icc->ic_read_byte = radeonfb_i2c_read_byte;
215 		icc->ic_write_byte = radeonfb_i2c_write_byte;
216 	}
217 
218 	/* index == ddctype (RADEON_DDC_XX) - 1 */
219 	sc->sc_i2c[0].ric_register = RADEON_GPIO_MONID;
220 	sc->sc_i2c[1].ric_register = RADEON_GPIO_DVI_DDC;
221 	sc->sc_i2c[2].ric_register = RADEON_GPIO_VGA_DDC;
222 	sc->sc_i2c[3].ric_register = RADEON_GPIO_CRT2_DDC;
223 }
224 
225 int
radeonfb_i2c_read_edid(struct radeonfb_softc * sc,int ddctype,uint8_t * data)226 radeonfb_i2c_read_edid(struct radeonfb_softc *sc, int ddctype, uint8_t *data)
227 {
228 
229 	if ((ddctype < 1) || (ddctype > 4))
230 		return EINVAL;
231 
232 	ddctype--;
233 	return (ddc_read_edid(&sc->sc_i2c[ddctype].ric_controller, data, 128));
234 }
235