1 /* $NetBSD: gpioregulator.c,v 1.4 2021/01/27 03:10:21 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 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 1.4 2021/01/27 03:10:21 thorpej 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 const struct device_compatible_entry compat_data[] = { 87 { .compat = "regulator-gpio" }, 88 DEVICE_COMPAT_EOL 89 }; 90 91 static int 92 gpioregulator_match(device_t parent, cfdata_t cf, void *aux) 93 { 94 const struct fdt_attach_args *faa = aux; 95 96 return of_compatible_match(faa->faa_phandle, compat_data); 97 } 98 99 static void 100 gpioregulator_attach(device_t parent, device_t self, void *aux) 101 { 102 struct gpioregulator_softc * const sc = device_private(self); 103 const struct fdt_attach_args *faa = aux; 104 const int phandle = faa->faa_phandle; 105 const uint32_t *pstates; 106 uint32_t mask; 107 u_int gpios_states; 108 char *name; 109 int len, n; 110 111 sc->sc_dev = self; 112 sc->sc_phandle = phandle; 113 114 aprint_naive("\n"); 115 116 len = OF_getproplen(phandle, "regulator-name"); 117 if (len > 0) { 118 name = kmem_zalloc(len, KM_SLEEP); 119 if (OF_getprop(phandle, "regulator-name", name, len) == len) { 120 aprint_normal(": %s\n", name); 121 } else { 122 aprint_normal("\n"); 123 } 124 kmem_free(name, len); 125 } else { 126 aprint_normal("\n"); 127 } 128 129 pstates = fdtbus_get_prop(phandle, "states", &len); 130 if (pstates == NULL || len < 8 || len % 8 != 0) { 131 aprint_error_dev(self, "invalid 'states' property\n"); 132 return; 133 } 134 135 mask = 0; 136 sc->sc_nstates = len / (sizeof(uint32_t) * 2); 137 sc->sc_states = kmem_zalloc( 138 sc->sc_nstates * sizeof(struct gpioregulator_state), KM_SLEEP); 139 for (n = 0; n < sc->sc_nstates; n++) { 140 sc->sc_states[n].st_val = be32toh(pstates[n * 2 + 0]); 141 sc->sc_states[n].st_mask = be32toh(pstates[n * 2 + 1]); 142 mask |= sc->sc_states[n].st_mask; 143 } 144 145 sc->sc_gpioflags = GPIO_PIN_OUTPUT; 146 if (of_getprop_bool(phandle, "gpio-open-drain")) 147 sc->sc_gpioflags |= GPIO_PIN_OPENDRAIN; 148 149 sc->sc_always_on = of_getprop_bool(phandle, "regulator-always-on"); 150 sc->sc_boot_on = of_getprop_bool(phandle, "regulator-boot-on"); 151 sc->sc_enable_val = of_getprop_bool(phandle, "enable-active-high"); 152 if (of_getprop_uint32(phandle, "startup-delay-us", &sc->sc_delay) != 0) 153 sc->sc_delay = 0; 154 155 /* "enable-gpio" property (optional) */ 156 sc->sc_pin_enable = fdtbus_gpio_acquire(phandle, "enable-gpio", 157 sc->sc_gpioflags); 158 159 /* "gpios" property */ 160 sc->sc_npins = 32 - __builtin_clz(mask); 161 sc->sc_pins = kmem_zalloc(sc->sc_npins * sizeof(sc->sc_pins), KM_SLEEP); 162 for (n = 0; n < sc->sc_npins; n++) { 163 sc->sc_pins[n] = fdtbus_gpio_acquire_index(phandle, "gpios", 164 n, sc->sc_gpioflags); 165 if (sc->sc_pins[n] == NULL) { 166 aprint_error_dev(self, "cannot get pin %d\n", n); 167 return; 168 } 169 } 170 171 /* "gpios-states" property */ 172 if (of_getprop_uint32(phandle, "gpios-states", &gpios_states) != 0) 173 gpios_states = 0; 174 175 /* Set initial state */ 176 for (n = 0; n < sc->sc_npins; n++) 177 fdtbus_gpio_write(sc->sc_pins[n], (gpios_states >> n) & 1); 178 179 fdtbus_register_regulator_controller(self, phandle, 180 &gpioregulator_funcs); 181 182 /* 183 * If the regulator is flagged as always on or enabled at boot, 184 * ensure that it is enabled 185 */ 186 if (sc->sc_always_on || sc->sc_boot_on) 187 gpioregulator_enable(self, true); 188 } 189 190 static int 191 gpioregulator_acquire(device_t dev) 192 { 193 return 0; 194 } 195 196 static void 197 gpioregulator_release(device_t dev) 198 { 199 } 200 201 static int 202 gpioregulator_enable(device_t dev, bool enable) 203 { 204 struct gpioregulator_softc * const sc = device_private(dev); 205 206 if (enable) { 207 if (sc->sc_pin_enable != NULL) 208 fdtbus_gpio_write_raw(sc->sc_pin_enable, sc->sc_enable_val); 209 if (sc->sc_delay > 0) 210 delay(sc->sc_delay); 211 } else { 212 if (sc->sc_always_on) 213 return EIO; 214 fdtbus_gpio_write_raw(sc->sc_pin_enable, !sc->sc_enable_val); 215 } 216 return 0; 217 } 218 219 static int 220 gpioregulator_set_voltage(device_t dev, u_int min_uvolt, u_int max_uvolt) 221 { 222 struct gpioregulator_softc * const sc = device_private(dev); 223 const struct gpioregulator_state *state = NULL; 224 int n; 225 226 for (n = 0; n < sc->sc_nstates; n++) 227 if (sc->sc_states[n].st_val >= min_uvolt && 228 sc->sc_states[n].st_val <= max_uvolt) { 229 state = &sc->sc_states[n]; 230 break; 231 } 232 if (state == NULL) 233 return EINVAL; 234 235 for (n = 0; n < sc->sc_npins; n++) 236 fdtbus_gpio_write(sc->sc_pins[n], (state->st_mask >> n) & 1); 237 238 if (sc->sc_delay > 0) 239 delay(sc->sc_delay); 240 241 return 0; 242 } 243 244 static int 245 gpioregulator_get_voltage(device_t dev, u_int *puvolt) 246 { 247 struct gpioregulator_softc * const sc = device_private(dev); 248 uint32_t mask = 0; 249 int n, val; 250 251 for (n = 0; n < sc->sc_npins; n++) { 252 val = fdtbus_gpio_read(sc->sc_pins[n]); 253 mask |= (val << n); 254 } 255 256 for (n = 0; n < sc->sc_nstates; n++) 257 if (sc->sc_states[n].st_mask == mask) { 258 *puvolt = sc->sc_states[n].st_val; 259 return 0; 260 } 261 262 return EIO; 263 } 264
Indexes created Sat Sep 20 22:09:52 GMT 2025