gpioregulator.c revision 1.1.6.1
1 /* $NetBSD: gpioregulator.c,v 1.1.6.1 2019/01/26 22:00:06 pgoyette 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: gpioregulator.c,v 1.1.6.1 2019/01/26 22:00:06 pgoyette Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/device.h> 35 #include <sys/kmem.h> 36 #include <sys/bus.h> 37 #include <sys/gpio.h> 38 39 #include <dev/fdt/fdtvar.h> 40 41 static int gpioregulator_match(device_t, cfdata_t, void *); 42 static void gpioregulator_attach(device_t, device_t, void *); 43 44 static int gpioregulator_acquire(device_t); 45 static void gpioregulator_release(device_t); 46 static int gpioregulator_enable(device_t, bool); 47 static int gpioregulator_set_voltage(device_t, u_int, u_int); 48 static int gpioregulator_get_voltage(device_t, u_int *); 49 50 static const struct fdtbus_regulator_controller_func gpioregulator_funcs = { 51 .acquire = gpioregulator_acquire, 52 .release = gpioregulator_release, 53 .enable = gpioregulator_enable, 54 .set_voltage = gpioregulator_set_voltage, 55 .get_voltage = gpioregulator_get_voltage, 56 }; 57 58 struct gpioregulator_state { 59 u_int st_val; 60 u_int st_mask; 61 }; 62 63 struct gpioregulator_softc { 64 device_t sc_dev; 65 int sc_phandle; 66 67 struct fdtbus_gpio_pin *sc_pin_enable; 68 69 struct fdtbus_gpio_pin **sc_pins; 70 u_int sc_npins; 71 72 struct gpioregulator_state *sc_states; 73 u_int sc_nstates; 74 75 bool sc_always_on; 76 bool sc_boot_on; 77 bool sc_enable_val; 78 uint32_t sc_delay; 79 80 int sc_gpioflags; 81 }; 82 83 CFATTACH_DECL_NEW(gregulator, sizeof(struct gpioregulator_softc), 84 gpioregulator_match, gpioregulator_attach, NULL, NULL); 85 86 static int 87 gpioregulator_match(device_t parent, cfdata_t cf, void *aux) 88 { 89 const char * const compatible[] = { "regulator-gpio", NULL }; 90 const struct fdt_attach_args *faa = aux; 91 92 return of_match_compatible(faa->faa_phandle, compatible); 93 } 94 95 static void 96 gpioregulator_attach(device_t parent, device_t self, void *aux) 97 { 98 struct gpioregulator_softc * const sc = device_private(self); 99 const struct fdt_attach_args *faa = aux; 100 const int phandle = faa->faa_phandle; 101 const uint32_t *pstates; 102 uint32_t mask; 103 u_int gpios_states; 104 char *name; 105 int len, n; 106 107 sc->sc_dev = self; 108 sc->sc_phandle = phandle; 109 110 aprint_naive("\n"); 111 112 len = OF_getproplen(phandle, "regulator-name"); 113 if (len > 0) { 114 name = kmem_zalloc(len, KM_SLEEP); 115 if (OF_getprop(phandle, "regulator-name", name, len) == len) { 116 aprint_normal(": %s\n", name); 117 } else { 118 aprint_normal("\n"); 119 } 120 kmem_free(name, len); 121 } else { 122 aprint_normal("\n"); 123 } 124 125 pstates = fdtbus_get_prop(phandle, "states", &len); 126 if (pstates == NULL || len < 8 || len % 8 != 0) { 127 aprint_error_dev(self, "invalid 'states' property\n"); 128 return; 129 } 130 131 mask = 0; 132 sc->sc_nstates = len / (sizeof(uint32_t) * 2); 133 sc->sc_states = kmem_zalloc( 134 sc->sc_nstates * sizeof(struct gpioregulator_state), KM_SLEEP); 135 for (n = 0; n < sc->sc_nstates; n++) { 136 sc->sc_states[n].st_val = be32toh(pstates[n * 2 + 0]); 137 sc->sc_states[n].st_mask = be32toh(pstates[n * 2 + 1]); 138 mask |= sc->sc_states[n].st_mask; 139 } 140 141 sc->sc_gpioflags = GPIO_PIN_OUTPUT; 142 if (of_getprop_bool(phandle, "gpio-open-drain")) 143 sc->sc_gpioflags |= GPIO_PIN_OPENDRAIN; 144 145 sc->sc_always_on = of_getprop_bool(phandle, "regulator-always-on"); 146 sc->sc_boot_on = of_getprop_bool(phandle, "regulator-boot-on"); 147 sc->sc_enable_val = of_getprop_bool(phandle, "enable-active-high"); 148 if (of_getprop_uint32(phandle, "startup-delay-us", &sc->sc_delay) != 0) 149 sc->sc_delay = 0; 150 151 /* "enable-gpio" property (optional) */ 152 sc->sc_pin_enable = fdtbus_gpio_acquire(phandle, "enable-gpio", 153 sc->sc_gpioflags); 154 155 /* "gpios" property */ 156 sc->sc_npins = 32 - __builtin_clz(mask); 157 sc->sc_pins = kmem_zalloc(sc->sc_npins * sizeof(sc->sc_pins), KM_SLEEP); 158 for (n = 0; n < sc->sc_npins; n++) { 159 sc->sc_pins[n] = fdtbus_gpio_acquire_index(phandle, "gpios", 160 n, sc->sc_gpioflags); 161 if (sc->sc_pins[n] == NULL) { 162 aprint_error_dev(self, "cannot get pin %d\n", n); 163 return; 164 } 165 } 166 167 /* "gpios-states" property */ 168 if (of_getprop_uint32(phandle, "gpios-states", &gpios_states) != 0) 169 gpios_states = 0; 170 171 /* Set initial state */ 172 for (n = 0; n < sc->sc_npins; n++) 173 fdtbus_gpio_write(sc->sc_pins[n], (gpios_states >> n) & 1); 174 175 fdtbus_register_regulator_controller(self, phandle, 176 &gpioregulator_funcs); 177 178 /* 179 * If the regulator is flagged as always on or enabled at boot, 180 * ensure that it is enabled 181 */ 182 if (sc->sc_always_on || sc->sc_boot_on) 183 gpioregulator_enable(self, true); 184 } 185 186 static int 187 gpioregulator_acquire(device_t dev) 188 { 189 return 0; 190 } 191 192 static void 193 gpioregulator_release(device_t dev) 194 { 195 } 196 197 static int 198 gpioregulator_enable(device_t dev, bool enable) 199 { 200 struct gpioregulator_softc * const sc = device_private(dev); 201 202 if (enable) { 203 if (sc->sc_pin_enable != NULL) 204 fdtbus_gpio_write_raw(sc->sc_pin_enable, sc->sc_enable_val); 205 if (sc->sc_delay > 0) 206 delay(sc->sc_delay); 207 } else { 208 if (sc->sc_always_on) 209 return EIO; 210 fdtbus_gpio_write_raw(sc->sc_pin_enable, !sc->sc_enable_val); 211 } 212 return 0; 213 } 214 215 static int 216 gpioregulator_set_voltage(device_t dev, u_int min_uvolt, u_int max_uvolt) 217 { 218 struct gpioregulator_softc * const sc = device_private(dev); 219 const struct gpioregulator_state *state = NULL; 220 int n; 221 222 for (n = 0; n < sc->sc_nstates; n++) 223 if (sc->sc_states[n].st_val >= min_uvolt && 224 sc->sc_states[n].st_val <= max_uvolt) { 225 state = &sc->sc_states[n]; 226 break; 227 } 228 if (state == NULL) 229 return EINVAL; 230 231 for (n = 0; n < sc->sc_npins; n++) 232 fdtbus_gpio_write(sc->sc_pins[n], (state->st_mask >> n) & 1); 233 234 if (sc->sc_delay > 0) 235 delay(sc->sc_delay); 236 237 return 0; 238 } 239 240 static int 241 gpioregulator_get_voltage(device_t dev, u_int *puvolt) 242 { 243 struct gpioregulator_softc * const sc = device_private(dev); 244 uint32_t mask = 0; 245 int n, val; 246 247 for (n = 0; n < sc->sc_npins; n++) { 248 val = fdtbus_gpio_read(sc->sc_pins[n]); 249 mask |= (val << n); 250 } 251 252 for (n = 0; n < sc->sc_nstates; n++) 253 if (sc->sc_states[n].st_mask == mask) { 254 *puvolt = sc->sc_states[n].st_val; 255 return 0; 256 } 257 258 return EIO; 259 } 260
Indexes created Wed Oct 15 16:09:53 GMT 2025