245 lines
6.5 KiB
C
245 lines
6.5 KiB
C
/*-
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* Copyright (C) 2008 MARVELL INTERNATIONAL LTD.
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* All rights reserved.
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*
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* Developed by Semihalf.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of MARVELL nor the names of contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* Driver for the TWSI (aka I2C, aka IIC) bus controller found on Marvell
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* and Allwinner SoCs. Supports master operation only, and works in polling mode.
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*
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* Calls to DELAY() are needed per Application Note AN-179 "TWSI Software
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* Guidelines for Discovery(TM), Horizon (TM) and Feroceon(TM) Devices".
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/kernel.h>
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#include <sys/module.h>
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#include <sys/resource.h>
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#include <machine/_inttypes.h>
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#include <machine/bus.h>
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#include <machine/resource.h>
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#include <sys/rman.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <dev/iicbus/iiconf.h>
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#include <dev/iicbus/iicbus.h>
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#include <dev/ofw/ofw_bus.h>
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#include <dev/ofw/ofw_bus_subr.h>
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#ifdef EXT_RESOURCES
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#include <dev/extres/clk/clk.h>
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#endif
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#include <arm/mv/mvreg.h>
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#include <arm/mv/mvvar.h>
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#include <dev/iicbus/twsi/twsi.h>
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#include "iicbus_if.h"
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#define MV_TWSI_NAME "twsi"
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#define IICBUS_DEVNAME "iicbus"
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#define TWSI_ADDR 0x00
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#define TWSI_DATA 0x04
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#define TWSI_CNTR 0x08
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#define TWSI_XADDR 0x10
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#define TWSI_STAT 0x0c
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#define TWSI_BAUD_RATE 0x0c
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#define TWSI_SRST 0x1c
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#define TWSI_BAUD_RATE_RAW(C,M,N) ((C)/((10*(M+1))<<(N+1)))
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#define TWSI_BAUD_RATE_SLOW 50000 /* 50kHz */
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#define TWSI_BAUD_RATE_FAST 100000 /* 100kHz */
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#define TWSI_DEBUG
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#undef TWSI_DEBUG
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#ifdef TWSI_DEBUG
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#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt,##args); } while (0)
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#else
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#define debugf(fmt, args...)
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#endif
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static phandle_t mv_twsi_get_node(device_t, device_t);
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static int mv_twsi_probe(device_t);
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static int mv_twsi_attach(device_t);
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static struct ofw_compat_data compat_data[] = {
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{ "mrvl,twsi", true },
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{ "marvell,mv64xxx-i2c", true },
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{ "marvell,mv78230-i2c", true },
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{ NULL, false }
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};
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static device_method_t mv_twsi_methods[] = {
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/* device interface */
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DEVMETHOD(device_probe, mv_twsi_probe),
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DEVMETHOD(device_attach, mv_twsi_attach),
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/* ofw_bus interface */
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DEVMETHOD(ofw_bus_get_node, mv_twsi_get_node),
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DEVMETHOD_END
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};
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DEFINE_CLASS_1(twsi, mv_twsi_driver, mv_twsi_methods,
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sizeof(struct twsi_softc), twsi_driver);
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static devclass_t mv_twsi_devclass;
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DRIVER_MODULE(twsi, simplebus, mv_twsi_driver, mv_twsi_devclass, 0, 0);
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DRIVER_MODULE(iicbus, twsi, iicbus_driver, iicbus_devclass, 0, 0);
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MODULE_DEPEND(twsi, iicbus, 1, 1, 1);
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SIMPLEBUS_PNP_INFO(compat_data);
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static phandle_t
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mv_twsi_get_node(device_t bus, device_t dev)
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{
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/* Used by ofw_iicbus. */
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return (ofw_bus_get_node(bus));
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}
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static int
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mv_twsi_probe(device_t dev)
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{
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struct twsi_softc *sc;
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sc = device_get_softc(dev);
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if (!ofw_bus_status_okay(dev))
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return (ENXIO);
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if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
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return (ENXIO);
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device_set_desc(dev, "Marvell Integrated I2C Bus Controller");
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return (BUS_PROBE_DEFAULT);
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}
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#define ABSSUB(a,b) (((a) > (b)) ? (a) - (b) : (b) - (a))
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static void
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mv_twsi_cal_baud_rate(struct twsi_softc *sc, const uint32_t target,
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struct twsi_baud_rate *rate)
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{
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uint64_t clk;
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uint32_t cur, diff, diff0;
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int m, n, m0, n0;
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/* Calculate baud rate. */
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m0 = n0 = 4; /* Default values on reset */
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diff0 = 0xffffffff;
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#ifdef __aarch64__
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clk_get_freq(sc->clk_core, &clk);
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#else
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clk = get_tclk();
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#endif
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for (n = 0; n < 8; n++) {
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for (m = 0; m < 16; m++) {
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cur = TWSI_BAUD_RATE_RAW(clk,m,n);
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diff = ABSSUB(target, cur);
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if (diff < diff0) {
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m0 = m;
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n0 = n;
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diff0 = diff;
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}
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}
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}
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rate->raw = TWSI_BAUD_RATE_RAW(clk, m0, n0);
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rate->param = TWSI_BAUD_RATE_PARAM(m0, n0);
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rate->m = m0;
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rate->n = n0;
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}
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static int
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mv_twsi_attach(device_t dev)
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{
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struct twsi_softc *sc;
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#ifdef __aarch64__
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int error;
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#endif
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sc = device_get_softc(dev);
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sc->dev = dev;
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#ifdef __aarch64__
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/* Activate clock */
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error = clk_get_by_ofw_index(dev, 0, 0, &sc->clk_core);
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if (error != 0) {
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device_printf(dev, "could not find core clock\n");
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return (error);
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}
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error = clk_enable(sc->clk_core);
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if (error != 0) {
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device_printf(dev, "could not enable core clock\n");
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return (error);
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}
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if (clk_get_by_ofw_index(dev, 0, 1, &sc->clk_reg) == 0) {
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error = clk_enable(sc->clk_reg);
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if (error != 0) {
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device_printf(dev, "could not enable core clock\n");
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return (error);
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}
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}
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#endif
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mv_twsi_cal_baud_rate(sc, TWSI_BAUD_RATE_SLOW, &sc->baud_rate[IIC_SLOW]);
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mv_twsi_cal_baud_rate(sc, TWSI_BAUD_RATE_FAST, &sc->baud_rate[IIC_FAST]);
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if (bootverbose)
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device_printf(dev, "calculated baud rates are:\n"
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" %" PRIu32 " kHz (M=%d, N=%d) for slow,\n"
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" %" PRIu32 " kHz (M=%d, N=%d) for fast.\n",
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sc->baud_rate[IIC_SLOW].raw / 1000,
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sc->baud_rate[IIC_SLOW].m,
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sc->baud_rate[IIC_SLOW].n,
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sc->baud_rate[IIC_FAST].raw / 1000,
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sc->baud_rate[IIC_FAST].m,
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sc->baud_rate[IIC_FAST].n);
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sc->reg_data = TWSI_DATA;
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sc->reg_slave_addr = TWSI_ADDR;
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sc->reg_slave_ext_addr = TWSI_XADDR;
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sc->reg_control = TWSI_CNTR;
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sc->reg_status = TWSI_STAT;
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sc->reg_baud_rate = TWSI_BAUD_RATE;
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sc->reg_soft_reset = TWSI_SRST;
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return (twsi_attach(dev));
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}
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