tcagpio.c revision 1.6
1 /* $NetBSD: tcagpio.c,v 1.6 2021/01/17 21:42:35 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 1.6 2021/01/17 21:42:35 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 74 { 0 } 75 }; 76 77 static uint8_t 78 tcagpio_read(struct tcagpio_softc *sc, uint8_t reg, int flags) 79 { 80 uint8_t val = 0; 81 int error; 82 83 error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP, sc->sc_addr, 84 ®, 1, &val, 1, flags); 85 if (error != 0) 86 aprint_error_dev(sc->sc_dev, "error reading reg %#x: %d\n", reg, error); 87 88 return val; 89 } 90 91 static void 92 tcagpio_write(struct tcagpio_softc *sc, uint8_t reg, uint8_t val, int flags) 93 { 94 uint8_t buf[2]; 95 int error; 96 97 buf[0] = reg; 98 buf[1] = val; 99 100 error = iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP, sc->sc_addr, 101 NULL, 0, buf, 2, flags); 102 if (error != 0) 103 aprint_error_dev(sc->sc_dev, "error writing reg %#x: %d\n", reg, error); 104 } 105 106 #define I2C_READ(sc, reg) tcagpio_read((sc), (reg), 0) 107 #define I2C_WRITE(sc, reg, val) tcagpio_write((sc), (reg), (val), 0) 108 #define I2C_LOCK(sc) iic_acquire_bus((sc)->sc_i2c, 0) 109 #define I2C_UNLOCK(sc) iic_release_bus((sc)->sc_i2c, 0) 110 111 static int 112 tcagpio_gpio_config(struct tcagpio_softc *sc, int pin, int flags) 113 { 114 uint16_t gpio; 115 116 KASSERT(pin >= 0 && pin < sc->sc_npins); 117 118 gpio = I2C_READ(sc, PORT_CFG(pin)); 119 120 switch (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) { 121 case GPIO_PIN_INPUT: 122 gpio |= PORT_BIT(pin); 123 break; 124 case GPIO_PIN_OUTPUT: 125 gpio &= ~PORT_BIT(pin); 126 break; 127 default: 128 return EINVAL; 129 } 130 131 I2C_WRITE(sc, PORT_CFG(pin), gpio); 132 133 return 0; 134 } 135 136 static void * 137 tcagpio_gpio_acquire(device_t dev, const void *data, size_t len, int flags) 138 { 139 struct tcagpio_softc * const sc = device_private(dev); 140 struct tcagpio_pin *gpin; 141 const u_int *gpio = data; 142 int error; 143 144 if (len != 12) 145 return NULL; 146 147 const uint8_t pin = be32toh(gpio[1]) & 0xff; 148 const bool actlo = (be32toh(gpio[2]) & __BIT(0)) != 0; 149 150 if (pin >= sc->sc_npins) 151 return NULL; 152 153 I2C_LOCK(sc); 154 error = tcagpio_gpio_config(sc, pin, flags); 155 I2C_UNLOCK(sc); 156 157 if (error != 0) { 158 device_printf(dev, "bad pin %d config %#x\n", pin, flags); 159 return NULL; 160 } 161 162 gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP); 163 gpin->pin_sc = sc; 164 gpin->pin_num = pin; 165 gpin->pin_flags = flags; 166 gpin->pin_actlo = actlo; 167 168 return gpin; 169 } 170 171 static void 172 tcagpio_gpio_release(device_t dev, void *priv) 173 { 174 struct tcagpio_softc * const sc = device_private(dev); 175 struct tcagpio_pin *gpin = priv; 176 177 I2C_LOCK(sc); 178 tcagpio_gpio_config(sc, gpin->pin_num, GPIO_PIN_INPUT); 179 I2C_UNLOCK(sc); 180 181 kmem_free(gpin, sizeof(*gpin)); 182 } 183 184 static int 185 tcagpio_gpio_read(device_t dev, void *priv, bool raw) 186 { 187 struct tcagpio_softc * const sc = device_private(dev); 188 struct tcagpio_pin *gpin = priv; 189 uint8_t gpio; 190 int val; 191 192 I2C_LOCK(sc); 193 gpio = I2C_READ(sc, PORT_IN(gpin->pin_num)); 194 I2C_UNLOCK(sc); 195 196 val = __SHIFTOUT(gpio, PORT_BIT(gpin->pin_num)); 197 if (!raw && gpin->pin_actlo) 198 val = !val; 199 200 #ifdef TCAGPIO_DEBUG 201 device_printf(sc->sc_dev, "GPIO%d rd %02x (%d %d)\n", 202 gpin->pin_num, gpio, 203 (int)__SHIFTOUT(gpio, PORT_BIT(gpin->pin_num)), val); 204 #endif 205 206 return val; 207 } 208 209 static void 210 tcagpio_gpio_write(device_t dev, void *priv, int val, bool raw) 211 { 212 struct tcagpio_softc * const sc = device_private(dev); 213 struct tcagpio_pin *gpin = priv; 214 uint8_t gpio; 215 216 if (!raw && gpin->pin_actlo) 217 val = !val; 218 219 I2C_LOCK(sc); 220 gpio = I2C_READ(sc, PORT_OUT(gpin->pin_num)); 221 gpio &= ~PORT_BIT(gpin->pin_num); 222 gpio |= __SHIFTIN(val, PORT_BIT(gpin->pin_num)); 223 #ifdef TCAGPIO_DEBUG 224 device_printf(sc->sc_dev, "GPIO%d wr %02x -> %02x\n", 225 gpin->pin_num, 226 I2C_READ(sc, PORT_OUT(gpin->pin_num)), gpio); 227 #endif 228 I2C_WRITE(sc, PORT_OUT(gpin->pin_num), gpio); 229 I2C_UNLOCK(sc); 230 } 231 232 static struct fdtbus_gpio_controller_func tcagpio_gpio_funcs = { 233 .acquire = tcagpio_gpio_acquire, 234 .release = tcagpio_gpio_release, 235 .read = tcagpio_gpio_read, 236 .write = tcagpio_gpio_write, 237 }; 238 239 static void 240 tcagpio_gpio_attach(struct tcagpio_softc *sc) 241 { 242 fdtbus_register_gpio_controller(sc->sc_dev, sc->sc_phandle, 243 &tcagpio_gpio_funcs); 244 } 245 246 static int 247 tcagpio_match(device_t parent, cfdata_t match, void *aux) 248 { 249 struct i2c_attach_args *ia = aux; 250 int match_result; 251 252 if (iic_use_direct_match(ia, match, compat_data, &match_result)) 253 return match_result; 254 255 return 0; 256 } 257 258 static void 259 tcagpio_attach(device_t parent, device_t self, void *aux) 260 { 261 struct tcagpio_softc * const sc = device_private(self); 262 struct i2c_attach_args *ia = aux; 263 264 sc->sc_dev = self; 265 sc->sc_i2c = ia->ia_tag; 266 sc->sc_addr = ia->ia_addr; 267 sc->sc_phandle = ia->ia_cookie; 268 sc->sc_npins = TCA_PIN_COUNT; 269 270 aprint_naive("\n"); 271 aprint_normal(": I2C/SMBus I/O Expander\n"); 272 273 tcagpio_gpio_attach(sc); 274 } 275 276 CFATTACH_DECL_NEW(tcagpio, sizeof(struct tcagpio_softc), 277 tcagpio_match, tcagpio_attach, NULL, NULL); 278
Indexes created Tue Sep 30 20:09:53 GMT 2025