1 /* $NetBSD: tcagpio.c,v 1.8 2021/01/27 02:29:48 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
5 * All rights reserved.
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 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: tcagpio.c,v 1.8 2021/01/27 02:29:48 thorpej Exp $");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/device.h>
36 #include <sys/conf.h>
37 #include <sys/bus.h>
38 #include <sys/kmem.h>
39 #include <sys/gpio.h>
40
41 #include <dev/i2c/i2cvar.h>
42
43 #include <dev/fdt/fdtvar.h>
44
45 #define PORT_BANK(pin) (pin / 8)
46 #define PORT_BIT(pin) __BIT(pin % 8)
47
48 #define PORT_IN(pin) (0x00 + PORT_BANK(pin))
49 #define PORT_OUT(pin) (0x02 + PORT_BANK(pin))
50 #define PORT_POLARITY(pin) (0x04 + PORT_BANK(pin))
51 #define PORT_CFG(pin) (0x06 + PORT_BANK(pin))
52
53 #define TCA_PIN_COUNT 16
54
55 struct tcagpio_softc {
56 device_t sc_dev;
57 i2c_tag_t sc_i2c;
58 i2c_addr_t sc_addr;
59 int sc_phandle;
60
61 int sc_npins;
62 };
63
64 struct tcagpio_pin {
65 struct tcagpio_softc *pin_sc;
66 int pin_num;
67 int pin_flags;
68 bool pin_actlo;
69 };
70
71 static const struct device_compatible_entry compat_data[] = {
72 { .compat = "ti,tca9539" },
73 DEVICE_COMPAT_EOL
74 };
75
76 static uint8_t
tcagpio_read(struct tcagpio_softc * sc,uint8_t reg,int flags)77 tcagpio_read(struct tcagpio_softc *sc, uint8_t reg, int flags)
78 {
79 uint8_t val = 0;
80 int error;
81
82 error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP, sc->sc_addr,
83 ®, 1, &val, 1, flags);
84 if (error != 0)
85 aprint_error_dev(sc->sc_dev, "error reading reg %#x: %d\n", reg, error);
86
87 return val;
88 }
89
90 static void
tcagpio_write(struct tcagpio_softc * sc,uint8_t reg,uint8_t val,int flags)91 tcagpio_write(struct tcagpio_softc *sc, uint8_t reg, uint8_t val, int flags)
92 {
93 uint8_t buf[2];
94 int error;
95
96 buf[0] = reg;
97 buf[1] = val;
98
99 error = iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
100 NULL, 0, buf, 2, flags);
101 if (error != 0)
102 aprint_error_dev(sc->sc_dev, "error writing reg %#x: %d\n", reg, error);
103 }
104
105 #define I2C_READ(sc, reg) tcagpio_read((sc), (reg), 0)
106 #define I2C_WRITE(sc, reg, val) tcagpio_write((sc), (reg), (val), 0)
107 #define I2C_LOCK(sc) iic_acquire_bus((sc)->sc_i2c, 0)
108 #define I2C_UNLOCK(sc) iic_release_bus((sc)->sc_i2c, 0)
109
110 static int
tcagpio_gpio_config(struct tcagpio_softc * sc,int pin,int flags)111 tcagpio_gpio_config(struct tcagpio_softc *sc, int pin, int flags)
112 {
113 uint16_t gpio;
114
115 KASSERT(pin >= 0 && pin < sc->sc_npins);
116
117 gpio = I2C_READ(sc, PORT_CFG(pin));
118
119 switch (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
120 case GPIO_PIN_INPUT:
121 gpio |= PORT_BIT(pin);
122 break;
123 case GPIO_PIN_OUTPUT:
124 gpio &= ~PORT_BIT(pin);
125 break;
126 default:
127 return EINVAL;
128 }
129
130 I2C_WRITE(sc, PORT_CFG(pin), gpio);
131
132 return 0;
133 }
134
135 static void *
tcagpio_gpio_acquire(device_t dev,const void * data,size_t len,int flags)136 tcagpio_gpio_acquire(device_t dev, const void *data, size_t len, int flags)
137 {
138 struct tcagpio_softc * const sc = device_private(dev);
139 struct tcagpio_pin *gpin;
140 const u_int *gpio = data;
141 int error;
142
143 if (len != 12)
144 return NULL;
145
146 const uint8_t pin = be32toh(gpio[1]) & 0xff;
147 const bool actlo = (be32toh(gpio[2]) & __BIT(0)) != 0;
148
149 if (pin >= sc->sc_npins)
150 return NULL;
151
152 I2C_LOCK(sc);
153 error = tcagpio_gpio_config(sc, pin, flags);
154 I2C_UNLOCK(sc);
155
156 if (error != 0) {
157 device_printf(dev, "bad pin %d config %#x\n", pin, flags);
158 return NULL;
159 }
160
161 gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP);
162 gpin->pin_sc = sc;
163 gpin->pin_num = pin;
164 gpin->pin_flags = flags;
165 gpin->pin_actlo = actlo;
166
167 return gpin;
168 }
169
170 static void
tcagpio_gpio_release(device_t dev,void * priv)171 tcagpio_gpio_release(device_t dev, void *priv)
172 {
173 struct tcagpio_softc * const sc = device_private(dev);
174 struct tcagpio_pin *gpin = priv;
175
176 I2C_LOCK(sc);
177 tcagpio_gpio_config(sc, gpin->pin_num, GPIO_PIN_INPUT);
178 I2C_UNLOCK(sc);
179
180 kmem_free(gpin, sizeof(*gpin));
181 }
182
183 static int
tcagpio_gpio_read(device_t dev,void * priv,bool raw)184 tcagpio_gpio_read(device_t dev, void *priv, bool raw)
185 {
186 struct tcagpio_softc * const sc = device_private(dev);
187 struct tcagpio_pin *gpin = priv;
188 uint8_t gpio;
189 int val;
190
191 I2C_LOCK(sc);
192 gpio = I2C_READ(sc, PORT_IN(gpin->pin_num));
193 I2C_UNLOCK(sc);
194
195 val = __SHIFTOUT(gpio, PORT_BIT(gpin->pin_num));
196 if (!raw && gpin->pin_actlo)
197 val = !val;
198
199 #ifdef TCAGPIO_DEBUG
200 device_printf(sc->sc_dev, "GPIO%d rd %02x (%d %d)\n",
201 gpin->pin_num, gpio,
202 (int)__SHIFTOUT(gpio, PORT_BIT(gpin->pin_num)), val);
203 #endif
204
205 return val;
206 }
207
208 static void
tcagpio_gpio_write(device_t dev,void * priv,int val,bool raw)209 tcagpio_gpio_write(device_t dev, void *priv, int val, bool raw)
210 {
211 struct tcagpio_softc * const sc = device_private(dev);
212 struct tcagpio_pin *gpin = priv;
213 uint8_t gpio;
214
215 if (!raw && gpin->pin_actlo)
216 val = !val;
217
218 I2C_LOCK(sc);
219 gpio = I2C_READ(sc, PORT_OUT(gpin->pin_num));
220 gpio &= ~PORT_BIT(gpin->pin_num);
221 gpio |= __SHIFTIN(val, PORT_BIT(gpin->pin_num));
222 #ifdef TCAGPIO_DEBUG
223 device_printf(sc->sc_dev, "GPIO%d wr %02x -> %02x\n",
224 gpin->pin_num,
225 I2C_READ(sc, PORT_OUT(gpin->pin_num)), gpio);
226 #endif
227 I2C_WRITE(sc, PORT_OUT(gpin->pin_num), gpio);
228 I2C_UNLOCK(sc);
229 }
230
231 static struct fdtbus_gpio_controller_func tcagpio_gpio_funcs = {
232 .acquire = tcagpio_gpio_acquire,
233 .release = tcagpio_gpio_release,
234 .read = tcagpio_gpio_read,
235 .write = tcagpio_gpio_write,
236 };
237
238 static void
tcagpio_gpio_attach(struct tcagpio_softc * sc)239 tcagpio_gpio_attach(struct tcagpio_softc *sc)
240 {
241 fdtbus_register_gpio_controller(sc->sc_dev, sc->sc_phandle,
242 &tcagpio_gpio_funcs);
243 }
244
245 static int
tcagpio_match(device_t parent,cfdata_t match,void * aux)246 tcagpio_match(device_t parent, cfdata_t match, void *aux)
247 {
248 struct i2c_attach_args *ia = aux;
249 int match_result;
250
251 if (iic_use_direct_match(ia, match, compat_data, &match_result))
252 return match_result;
253
254 return 0;
255 }
256
257 static void
tcagpio_attach(device_t parent,device_t self,void * aux)258 tcagpio_attach(device_t parent, device_t self, void *aux)
259 {
260 struct tcagpio_softc * const sc = device_private(self);
261 struct i2c_attach_args *ia = aux;
262
263 sc->sc_dev = self;
264 sc->sc_i2c = ia->ia_tag;
265 sc->sc_addr = ia->ia_addr;
266 sc->sc_phandle = ia->ia_cookie;
267 sc->sc_npins = TCA_PIN_COUNT;
268
269 aprint_naive("\n");
270 aprint_normal(": I2C/SMBus I/O Expander\n");
271
272 tcagpio_gpio_attach(sc);
273 }
274
275 CFATTACH_DECL_NEW(tcagpio, sizeof(struct tcagpio_softc),
276 tcagpio_match, tcagpio_attach, NULL, NULL);
277