1/*- 2 * Copyright (C) 2008 MARVELL INTERNATIONAL LTD. 3 * All rights reserved. 4 * 5 * Developed by Semihalf. 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 * 3. Neither the name of MARVELL nor the names of contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32/* 33 * Driver for the TWSI (aka I2C, aka IIC) bus controller found on Marvell 34 * and Allwinner SoCs. Supports master operation only, and works in polling mode. 35 * 36 * Calls to DELAY() are needed per Application Note AN-179 "TWSI Software 37 * Guidelines for Discovery(TM), Horizon (TM) and Feroceon(TM) Devices". 38 */ 39 40#include <sys/cdefs.h> 41__FBSDID("$FreeBSD: stable/11/sys/dev/iicbus/twsi/mv_twsi.c 355387 2019-12-04 13:28:17Z loos $"); 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/bus.h> 46#include <sys/kernel.h> 47#include <sys/module.h> 48#include <sys/resource.h> 49 50#include <machine/_inttypes.h> 51#include <machine/bus.h> 52#include <machine/resource.h> 53 54#include <sys/rman.h> 55 56#include <sys/lock.h> 57#include <sys/mutex.h> 58 59#include <dev/iicbus/iiconf.h> 60#include <dev/iicbus/iicbus.h> 61#include <dev/ofw/ofw_bus.h> 62#include <dev/ofw/ofw_bus_subr.h> 63 64#include <arm/mv/mvreg.h> 65#include <arm/mv/mvvar.h> 66#include <dev/iicbus/twsi/twsi.h> 67 68#include "iicbus_if.h" 69 70#define MV_TWSI_NAME "twsi" 71#define IICBUS_DEVNAME "iicbus" 72 73#define TWSI_ADDR 0x00 74#define TWSI_DATA 0x04 75#define TWSI_CNTR 0x08 76#define TWSI_XADDR 0x10 77#define TWSI_STAT 0x0c 78#define TWSI_BAUD_RATE 0x0c 79#define TWSI_SRST 0x1c 80 81#define TWSI_BAUD_RATE_RAW(C,M,N) ((C)/((10*(M+1))<<(N+1))) 82#define TWSI_BAUD_RATE_SLOW 50000 /* 50kHz */ 83#define TWSI_BAUD_RATE_FAST 100000 /* 100kHz */ 84 85#define TWSI_DEBUG 86#undef TWSI_DEBUG 87 88#ifdef TWSI_DEBUG 89#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt,##args); } while (0) 90#else 91#define debugf(fmt, args...) 92#endif 93 94static phandle_t mv_twsi_get_node(device_t, device_t); 95static int mv_twsi_probe(device_t); 96static int mv_twsi_attach(device_t); 97 98static struct ofw_compat_data compat_data[] = { 99 { "mrvl,twsi", true }, 100 { "marvell,mv64xxx-i2c", true }, 101 { NULL, false } 102}; 103 104static device_method_t mv_twsi_methods[] = { 105 /* device interface */ 106 DEVMETHOD(device_probe, mv_twsi_probe), 107 DEVMETHOD(device_attach, mv_twsi_attach), 108 109 /* ofw_bus interface */ 110 DEVMETHOD(ofw_bus_get_node, mv_twsi_get_node), 111 112 DEVMETHOD_END 113}; 114 115DEFINE_CLASS_1(twsi, mv_twsi_driver, mv_twsi_methods, 116 sizeof(struct twsi_softc), twsi_driver); 117 118static devclass_t mv_twsi_devclass; 119 120DRIVER_MODULE(twsi, simplebus, mv_twsi_driver, mv_twsi_devclass, 0, 0); 121DRIVER_MODULE(iicbus, twsi, iicbus_driver, iicbus_devclass, 0, 0); 122MODULE_DEPEND(twsi, iicbus, 1, 1, 1); 123 124static phandle_t 125mv_twsi_get_node(device_t bus, device_t dev) 126{ 127 128 /* Used by ofw_iicbus. */ 129 return (ofw_bus_get_node(bus)); 130} 131 132static int 133mv_twsi_probe(device_t dev) 134{ 135 struct twsi_softc *sc; 136 137 sc = device_get_softc(dev); 138 if (!ofw_bus_status_okay(dev)) 139 return (ENXIO); 140 141 if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data) 142 return (ENXIO); 143 144 sc->reg_data = TWSI_DATA; 145 sc->reg_slave_addr = TWSI_ADDR; 146 sc->reg_slave_ext_addr = TWSI_XADDR; 147 sc->reg_control = TWSI_CNTR; 148 sc->reg_status = TWSI_STAT; 149 sc->reg_baud_rate = TWSI_BAUD_RATE; 150 sc->reg_soft_reset = TWSI_SRST; 151 152 device_set_desc(dev, "Marvell Integrated I2C Bus Controller"); 153 return (BUS_PROBE_DEFAULT); 154} 155 156#define ABSSUB(a,b) (((a) > (b)) ? (a) - (b) : (b) - (a)) 157static void 158mv_twsi_cal_baud_rate(const uint32_t target, struct twsi_baud_rate *rate) 159{ 160 uint32_t clk, cur, diff, diff0; 161 int m, n, m0, n0; 162 163 /* Calculate baud rate. */ 164 m0 = n0 = 4; /* Default values on reset */ 165 diff0 = 0xffffffff; 166 clk = get_tclk(); 167 168 for (n = 0; n < 8; n++) { 169 for (m = 0; m < 16; m++) { 170 cur = TWSI_BAUD_RATE_RAW(clk,m,n); 171 diff = ABSSUB(target, cur); 172 if (diff < diff0) { 173 m0 = m; 174 n0 = n; 175 diff0 = diff; 176 } 177 } 178 } 179 rate->raw = TWSI_BAUD_RATE_RAW(clk, m0, n0); 180 rate->param = TWSI_BAUD_RATE_PARAM(m0, n0); 181 rate->m = m0; 182 rate->n = n0; 183} 184 185static int 186mv_twsi_attach(device_t dev) 187{ 188 struct twsi_softc *sc; 189 phandle_t child, iicbusnode; 190 device_t childdev; 191 struct iicbus_ivar *devi; 192 char dname[32]; /* 32 is taken from struct u_device */ 193 uint32_t paddr; 194 int len, error, ret; 195 196 sc = device_get_softc(dev); 197 198 mv_twsi_cal_baud_rate(TWSI_BAUD_RATE_SLOW, &sc->baud_rate[IIC_SLOW]); 199 mv_twsi_cal_baud_rate(TWSI_BAUD_RATE_FAST, &sc->baud_rate[IIC_FAST]); 200 if (bootverbose) 201 device_printf(dev, "calculated baud rates are:\n" 202 " %" PRIu32 " kHz (M=%d, N=%d) for slow,\n" 203 " %" PRIu32 " kHz (M=%d, N=%d) for fast.\n", 204 sc->baud_rate[IIC_SLOW].raw / 1000, 205 sc->baud_rate[IIC_SLOW].m, 206 sc->baud_rate[IIC_SLOW].n, 207 sc->baud_rate[IIC_FAST].raw / 1000, 208 sc->baud_rate[IIC_FAST].m, 209 sc->baud_rate[IIC_FAST].n); 210 211 212 ret = twsi_attach(dev); 213 if (ret != 0) 214 return (ret); 215 216 iicbusnode = 0; 217 /* Find iicbus as the child devices in the device tree. */ 218 for (child = OF_child(ofw_bus_get_node(dev)); child != 0; 219 child = OF_peer(child)) { 220 len = OF_getproplen(child, "model"); 221 if (len <= 0 || len > sizeof(dname)) 222 continue; 223 error = OF_getprop(child, "model", &dname, len); 224 if (error == -1) 225 continue; 226 len = strlen(dname); 227 if (len == strlen(IICBUS_DEVNAME) && 228 strncasecmp(dname, IICBUS_DEVNAME, len) == 0) { 229 iicbusnode = child; 230 break; 231 } 232 } 233 if (iicbusnode == 0) 234 goto attach_end; 235 236 /* Attach child devices onto iicbus. */ 237 for (child = OF_child(iicbusnode); child != 0; child = OF_peer(child)) { 238 /* Get slave address. */ 239 error = OF_getencprop(child, "i2c-address", &paddr, sizeof(paddr)); 240 if (error == -1) 241 error = OF_getencprop(child, "reg", &paddr, sizeof(paddr)); 242 if (error == -1) 243 continue; 244 245 /* Get device driver name. */ 246 len = OF_getproplen(child, "model"); 247 if (len <= 0 || len > sizeof(dname)) 248 continue; 249 OF_getprop(child, "model", &dname, len); 250 251 if (bootverbose) 252 device_printf(dev, "adding a device %s at %d.\n", 253 dname, paddr); 254 childdev = BUS_ADD_CHILD(sc->iicbus, 0, dname, -1); 255 devi = IICBUS_IVAR(childdev); 256 devi->addr = paddr; 257 } 258 259attach_end: 260 bus_generic_attach(sc->iicbus); 261 262 return (0); 263} 264