tcagpio.c revision 1.3
1 /* $NetBSD: tcagpio.c,v 1.3 2018/06/18 17:07:07 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 2017 Jared McNeill <jmcneill (at) 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 1.3 2018/06/18 17:07:07 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 char * compatible[] = { 72 "ti,tca9539", 73 NULL 74 }; 75 76 static const struct device_compatible_entry tcagpio_compat_data[] = { 77 DEVICE_COMPAT_ENTRY(compatible), 78 DEVICE_COMPAT_TERMINATOR 79 }; 80 81 static uint8_t 82 tcagpio_read(struct tcagpio_softc *sc, uint8_t reg, int flags) 83 { 84 uint8_t val = 0; 85 int error; 86 87 error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP, sc->sc_addr, 88 ®, 1, &val, 1, flags); 89 if (error != 0) 90 aprint_error_dev(sc->sc_dev, "error reading reg %#x: %d\n", reg, error); 91 92 return val; 93 } 94 95 static void 96 tcagpio_write(struct tcagpio_softc *sc, uint8_t reg, uint8_t val, int flags) 97 { 98 uint8_t buf[2]; 99 int error; 100 101 buf[0] = reg; 102 buf[1] = val; 103 104 error = iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, 105 NULL, 0, buf, 2, flags); 106 if (error != 0) 107 aprint_error_dev(sc->sc_dev, "error writing reg %#x: %d\n", reg, error); 108 } 109 110 #define I2C_READ(sc, reg) tcagpio_read((sc), (reg), I2C_F_POLL) 111 #define I2C_WRITE(sc, reg, val) tcagpio_write((sc), (reg), (val), I2C_F_POLL) 112 #define I2C_LOCK(sc) iic_acquire_bus((sc)->sc_i2c, I2C_F_POLL) 113 #define I2C_UNLOCK(sc) iic_release_bus((sc)->sc_i2c, I2C_F_POLL) 114 115 static int 116 tcagpio_gpio_config(struct tcagpio_softc *sc, int pin, int flags) 117 { 118 uint16_t gpio; 119 120 KASSERT(pin >= 0 && pin < sc->sc_npins); 121 122 gpio = I2C_READ(sc, PORT_CFG(pin)); 123 124 switch (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) { 125 case GPIO_PIN_INPUT: 126 gpio |= PORT_BIT(pin); 127 break; 128 case GPIO_PIN_OUTPUT: 129 gpio &= ~PORT_BIT(pin); 130 break; 131 default: 132 return EINVAL; 133 } 134 135 I2C_WRITE(sc, PORT_CFG(pin), gpio); 136 137 return 0; 138 } 139 140 static void * 141 tcagpio_gpio_acquire(device_t dev, const void *data, size_t len, int flags) 142 { 143 struct tcagpio_softc * const sc = device_private(dev); 144 struct tcagpio_pin *gpin; 145 const u_int *gpio = data; 146 int error; 147 148 if (len != 12) 149 return NULL; 150 151 const uint8_t pin = be32toh(gpio[1]) & 0xff; 152 const bool actlo = (be32toh(gpio[2]) & __BIT(0)) != 0; 153 154 if (pin >= sc->sc_npins) 155 return NULL; 156 157 I2C_LOCK(sc); 158 error = tcagpio_gpio_config(sc, pin, flags); 159 I2C_UNLOCK(sc); 160 161 if (error != 0) { 162 device_printf(dev, "bad pin %d config %#x\n", pin, flags); 163 return NULL; 164 } 165 166 gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP); 167 gpin->pin_sc = sc; 168 gpin->pin_num = pin; 169 gpin->pin_flags = flags; 170 gpin->pin_actlo = actlo; 171 172 return gpin; 173 } 174 175 static void 176 tcagpio_gpio_release(device_t dev, void *priv) 177 { 178 struct tcagpio_softc * const sc = device_private(dev); 179 struct tcagpio_pin *gpin = priv; 180 181 I2C_LOCK(sc); 182 tcagpio_gpio_config(sc, gpin->pin_num, GPIO_PIN_INPUT); 183 I2C_UNLOCK(sc); 184 185 kmem_free(gpin, sizeof(*gpin)); 186 } 187 188 static int 189 tcagpio_gpio_read(device_t dev, void *priv, bool raw) 190 { 191 struct tcagpio_softc * const sc = device_private(dev); 192 struct tcagpio_pin *gpin = priv; 193 uint8_t gpio; 194 int val; 195 196 I2C_LOCK(sc); 197 gpio = I2C_READ(sc, PORT_IN(gpin->pin_num)); 198 I2C_UNLOCK(sc); 199 200 val = __SHIFTOUT(gpio, PORT_BIT(gpin->pin_num)); 201 if (!raw && gpin->pin_actlo) 202 val = !val; 203 204 #ifdef TCAGPIO_DEBUG 205 device_printf(sc->sc_dev, "GPIO%d rd %02x (%d %d)\n", 206 gpin->pin_num, gpio, 207 (int)__SHIFTOUT(gpio, PORT_BIT(gpin->pin_num)), val); 208 #endif 209 210 return val; 211 } 212 213 static void 214 tcagpio_gpio_write(device_t dev, void *priv, int val, bool raw) 215 { 216 struct tcagpio_softc * const sc = device_private(dev); 217 struct tcagpio_pin *gpin = priv; 218 uint8_t gpio; 219 220 if (!raw && gpin->pin_actlo) 221 val = !val; 222 223 I2C_LOCK(sc); 224 gpio = I2C_READ(sc, PORT_OUT(gpin->pin_num)); 225 gpio &= ~PORT_BIT(gpin->pin_num); 226 gpio |= __SHIFTIN(val, PORT_BIT(gpin->pin_num)); 227 #ifdef TCAGPIO_DEBUG 228 device_printf(sc->sc_dev, "GPIO%d wr %02x -> %02x\n", 229 gpin->pin_num, 230 I2C_READ(sc, PORT_OUT(gpin->pin_num)), gpio); 231 #endif 232 I2C_WRITE(sc, PORT_OUT(gpin->pin_num), gpio); 233 I2C_UNLOCK(sc); 234 } 235 236 static struct fdtbus_gpio_controller_func tcagpio_gpio_funcs = { 237 .acquire = tcagpio_gpio_acquire, 238 .release = tcagpio_gpio_release, 239 .read = tcagpio_gpio_read, 240 .write = tcagpio_gpio_write, 241 }; 242 243 static void 244 tcagpio_gpio_attach(struct tcagpio_softc *sc) 245 { 246 fdtbus_register_gpio_controller(sc->sc_dev, sc->sc_phandle, 247 &tcagpio_gpio_funcs); 248 } 249 250 static int 251 tcagpio_match(device_t parent, cfdata_t match, void *aux) 252 { 253 struct i2c_attach_args *ia = aux; 254 int match_result; 255 256 if (iic_use_direct_match(ia, match, tcagpio_compat_data, &match_result)) 257 return match_result; 258 259 return 0; 260 } 261 262 static void 263 tcagpio_attach(device_t parent, device_t self, void *aux) 264 { 265 struct tcagpio_softc * const sc = device_private(self); 266 struct i2c_attach_args *ia = aux; 267 268 sc->sc_dev = self; 269 sc->sc_i2c = ia->ia_tag; 270 sc->sc_addr = ia->ia_addr; 271 sc->sc_phandle = ia->ia_cookie; 272 sc->sc_npins = TCA_PIN_COUNT; 273 274 aprint_naive("\n"); 275 aprint_normal(": I2C/SMBus I/O Expander\n"); 276 277 tcagpio_gpio_attach(sc); 278 } 279 280 CFATTACH_DECL_NEW(tcagpio, sizeof(struct tcagpio_softc), 281 tcagpio_match, tcagpio_attach, NULL, NULL); 282
Indexes created Tue Sep 30 11:09:46 GMT 2025