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