1 /* $NetBSD: apple_iic.c,v 1.1 2022/05/10 08:05:32 skrll Exp $ */
2 /* $OpenBSD: apliic.c,v 1.3 2022/02/14 14:55:53 kettenis Exp $ */
3
4 /*-
5 * Copyright (c) 2022 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Nick Hudson
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /*
34 * Copyright (c) 2021 Patrick Wildt <patrick@blueri.se>
35 *
36 * Permission to use, copy, modify, and distribute this software for any
37 * purpose with or without fee is hereby granted, provided that the above
38 * copyright notice and this permission notice appear in all copies.
39 *
40 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
41 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
42 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
43 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
44 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
45 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
46 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
47 */
48
49 #include <sys/param.h>
50
51 #include <sys/bus.h>
52 #include <sys/device.h>
53
54 #include <dev/i2c/i2cvar.h>
55
56 #include <dev/fdt/fdtvar.h>
57
58 /* Registers. */
59 #define I2C_MTXFIFO 0x00
60 #define I2C_MTXFIFO_DATA_MASK __BITS(7,0)
61 #define I2C_MTXFIFO_START __BIT(8)
62 #define I2C_MTXFIFO_STOP __BIT(9)
63 #define I2C_MTXFIFO_READ __BIT(10)
64 #define I2C_MRXFIFO 0x04
65 #define I2C_MRXFIFO_DATA_MASK __BITS(7,0)
66 #define I2C_MRXFIFO_EMPTY __BIT(8)
67 #define I2C_SMSTA 0x14
68 #define I2C_SMSTA_MTN __BIT(21)
69 #define I2C_SMSTA_XEN __BIT(27)
70 #define I2C_SMSTA_XBUSY __BIT(28)
71 #define I2C_CTL 0x1c
72 #define I2C_CTL_CLK_MASK __BITS(7,0)
73 #define I2C_CTL_MTR __BIT(9)
74 #define I2C_CTL_MRR __BIT(10)
75 #define I2C_CTL_EN __BIT(11)
76 #define I2C_REV 0x28
77
78 #define IIC_READ(sc, reg) \
79 (bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)))
80 #define IIC_WRITE(sc, reg, val) \
81 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
82 #define HSET4(sc, reg, bits) \
83 IIC_WRITE((sc), (reg), IIC_READ((sc), (reg)) | (bits))
84 #define HCLR4(sc, reg, bits) \
85 IIC_WRITE((sc), (reg), IIC_READ((sc), (reg)) & ~(bits))
86
87 struct apple_iic_softc {
88 device_t sc_dev;
89 bus_space_tag_t sc_bst;
90 bus_space_handle_t sc_bsh;
91
92 struct clk * sc_clk;
93 int sc_hwrev;
94 uint32_t sc_clkdiv;
95 struct i2c_controller sc_i2c;
96 };
97
98
99 static int
apple_iic_acquire_bus(void * cookie,int flags)100 apple_iic_acquire_bus(void *cookie, int flags)
101 {
102 return 0;
103 }
104
105 static void
apple_iic_release_bus(void * cookie,int flags)106 apple_iic_release_bus(void *cookie, int flags)
107 {
108 }
109
110 static int
apple_iic_exec(void * cookie,i2c_op_t op,i2c_addr_t addr,const void * cmd,size_t cmdlen,void * buf,size_t buflen,int flags)111 apple_iic_exec(void *cookie, i2c_op_t op, i2c_addr_t addr, const void *cmd,
112 size_t cmdlen, void *buf, size_t buflen, int flags)
113 {
114 struct apple_iic_softc *sc = cookie;
115 const uint8_t * const cmdbytes = cmd;
116 uint8_t * const bufbytes = buf;
117 uint32_t reg;
118 int i;
119
120 if (!I2C_OP_STOP_P(op))
121 return EINVAL;
122
123 IIC_WRITE(sc, I2C_SMSTA, 0xffffffff);
124
125 if (cmdlen > 0) {
126 IIC_WRITE(sc, I2C_MTXFIFO, I2C_MTXFIFO_START | addr << 1);
127 for (i = 0; i < cmdlen - 1; i++)
128 IIC_WRITE(sc, I2C_MTXFIFO, cmdbytes[i]);
129 IIC_WRITE(sc, I2C_MTXFIFO, cmdbytes[cmdlen - 1] |
130 (buflen == 0 ? I2C_MTXFIFO_STOP : 0));
131 }
132
133 if (buflen == 0)
134 return 0;
135
136 if (I2C_OP_READ_P(op)) {
137 IIC_WRITE(sc, I2C_MTXFIFO, I2C_MTXFIFO_START | addr << 1 | 1);
138 IIC_WRITE(sc, I2C_MTXFIFO, I2C_MTXFIFO_READ | buflen |
139 I2C_MTXFIFO_STOP);
140 for (i = 10; i > 0; i--) {
141 delay(1000);
142 reg = IIC_READ(sc, I2C_SMSTA);
143 if (reg & I2C_SMSTA_XEN)
144 break;
145 }
146 if (reg & I2C_SMSTA_MTN)
147 return ENXIO;
148 if (i == 0)
149 return ETIMEDOUT;
150 IIC_WRITE(sc, I2C_SMSTA, I2C_SMSTA_XEN);
151 for (i = 0; i < buflen; i++) {
152 reg = IIC_READ(sc, I2C_MRXFIFO);
153 if (reg & I2C_MRXFIFO_EMPTY)
154 return EIO;
155 bufbytes[i] = reg & I2C_MRXFIFO_DATA_MASK;
156 }
157 } else {
158 if (cmdlen == 0)
159 IIC_WRITE(sc, I2C_MTXFIFO, I2C_MTXFIFO_START | addr << 1);
160 for (i = 0; i < buflen - 1; i++)
161 IIC_WRITE(sc, I2C_MTXFIFO, bufbytes[i]);
162 IIC_WRITE(sc, I2C_MTXFIFO, bufbytes[buflen - 1] |
163 I2C_MTXFIFO_STOP);
164 }
165
166 return 0;
167 }
168
169
170 static const struct device_compatible_entry compat_data[] = {
171 { .compat = "apple,i2c" },
172 DEVICE_COMPAT_EOL
173 };
174
175 static int
apple_iic_match(device_t parent,cfdata_t cf,void * aux)176 apple_iic_match(device_t parent, cfdata_t cf, void *aux)
177 {
178 struct fdt_attach_args * const faa = aux;
179
180 return of_compatible_match(faa->faa_phandle, compat_data);
181 }
182
183 static void
apple_iic_attach(device_t parent,device_t self,void * aux)184 apple_iic_attach(device_t parent, device_t self, void *aux)
185 {
186 struct apple_iic_softc * const sc = device_private(self);
187 struct fdt_attach_args * const faa = aux;
188 const int phandle = faa->faa_phandle;
189 uint32_t clock_speed, bus_speed;
190 bus_addr_t addr;
191 bus_size_t size;
192
193 sc->sc_dev = self;
194 sc->sc_bst = faa->faa_bst;
195
196 int error = fdtbus_get_reg(phandle, 0, &addr, &size);
197 if (error) {
198 aprint_error(": unable to get device registers\n");
199 return;
200 }
201
202 /* Enable clock */
203 sc->sc_clk = fdtbus_clock_get_index(phandle, 0);
204 if (sc->sc_clk == NULL) {
205 aprint_error(": couldn't acquire clock\n");
206 return;
207 }
208
209 if (clk_enable(sc->sc_clk) != 0) {
210 aprint_error(": failed to enable clock\n");
211 return;
212 }
213
214 clock_speed = clk_get_rate(sc->sc_clk);
215
216 if (of_getprop_uint32(phandle, "clock-frequency",
217 &bus_speed) != 0) {
218 bus_speed = 100000;
219 }
220 bus_speed *= 16;
221
222 if (bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh)) {
223 aprint_error(": unable to map device\n");
224 return;
225 }
226
227 aprint_naive("\n");
228 aprint_normal(": Apple I2C\n");
229
230 sc->sc_clkdiv = howmany(clock_speed, bus_speed);
231 KASSERT(sc->sc_clkdiv <= __SHIFTOUT_MASK(I2C_CTL_CLK_MASK));
232
233 sc->sc_hwrev = IIC_READ(sc, I2C_REV);
234
235 IIC_WRITE(sc, I2C_CTL,
236 __SHIFTIN(sc->sc_clkdiv, I2C_CTL_CLK_MASK) |
237 I2C_CTL_MTR | I2C_CTL_MRR |
238 (sc->sc_hwrev >= 6 ? I2C_CTL_EN : 0));
239
240 iic_tag_init(&sc->sc_i2c);
241 sc->sc_i2c.ic_cookie = sc;
242 sc->sc_i2c.ic_acquire_bus = apple_iic_acquire_bus;
243 sc->sc_i2c.ic_release_bus = apple_iic_release_bus;
244 sc->sc_i2c.ic_exec = apple_iic_exec;
245
246 fdtbus_register_i2c_controller(&sc->sc_i2c, phandle);
247
248 fdtbus_attach_i2cbus(self, phandle, &sc->sc_i2c, iicbus_print);
249 }
250
251
252 CFATTACH_DECL_NEW(apple_iic, sizeof(struct apple_iic_softc),
253 apple_iic_match, apple_iic_attach, NULL, NULL);
254