aee2c3a86a
being overwritten, they are set only bits (cleared by hardware). Disable the Acknowledge of the controller slave address. The slave mode is not supported. Make sure the interrupt flag bit is being cleared as recommended, add a delay() _after_ clear the interrupt bit. Sponsored by: Rubicon Communications, LLC (Netgate)
486 lines
11 KiB
C
486 lines
11 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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#include <dev/iicbus/twsi/twsi.h>
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#include "iicbus_if.h"
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#define TWSI_CONTROL_ACK (1 << 2)
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#define TWSI_CONTROL_IFLG (1 << 3)
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#define TWSI_CONTROL_STOP (1 << 4)
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#define TWSI_CONTROL_START (1 << 5)
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#define TWSI_CONTROL_TWSIEN (1 << 6)
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#define TWSI_CONTROL_INTEN (1 << 7)
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#define TWSI_STATUS_START 0x08
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#define TWSI_STATUS_RPTD_START 0x10
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#define TWSI_STATUS_ADDR_W_ACK 0x18
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#define TWSI_STATUS_DATA_WR_ACK 0x28
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#define TWSI_STATUS_ADDR_R_ACK 0x40
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#define TWSI_STATUS_DATA_RD_ACK 0x50
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#define TWSI_STATUS_DATA_RD_NOACK 0x58
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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 struct resource_spec res_spec[] = {
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{ SYS_RES_MEMORY, 0, RF_ACTIVE },
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{ -1, 0 }
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};
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static __inline uint32_t
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TWSI_READ(struct twsi_softc *sc, bus_size_t off)
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{
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return (bus_read_4(sc->res[0], off));
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}
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static __inline void
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TWSI_WRITE(struct twsi_softc *sc, bus_size_t off, uint32_t val)
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{
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bus_write_4(sc->res[0], off, val);
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}
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static __inline void
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twsi_control_clear(struct twsi_softc *sc, uint32_t mask)
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{
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uint32_t val;
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val = TWSI_READ(sc, sc->reg_control);
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val &= ~(TWSI_CONTROL_STOP | TWSI_CONTROL_START);
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val &= ~mask;
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TWSI_WRITE(sc, sc->reg_control, val);
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}
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static __inline void
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twsi_control_set(struct twsi_softc *sc, uint32_t mask)
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{
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uint32_t val;
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val = TWSI_READ(sc, sc->reg_control);
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val &= ~(TWSI_CONTROL_STOP | TWSI_CONTROL_START);
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val |= mask;
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TWSI_WRITE(sc, sc->reg_control, val);
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}
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static __inline void
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twsi_clear_iflg(struct twsi_softc *sc)
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{
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DELAY(1000);
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twsi_control_clear(sc, TWSI_CONTROL_IFLG);
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DELAY(1000);
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}
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/*
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* timeout given in us
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* returns
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* 0 on successful mask change
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* non-zero on timeout
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*/
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static int
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twsi_poll_ctrl(struct twsi_softc *sc, int timeout, uint32_t mask)
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{
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timeout /= 10;
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while (!(TWSI_READ(sc, sc->reg_control) & mask)) {
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DELAY(10);
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if (--timeout < 0)
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return (timeout);
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}
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return (0);
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}
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/*
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* 'timeout' is given in us. Note also that timeout handling is not exact --
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* twsi_locked_start() total wait can be more than 2 x timeout
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* (twsi_poll_ctrl() is called twice). 'mask' can be either TWSI_STATUS_START
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* or TWSI_STATUS_RPTD_START
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*/
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static int
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twsi_locked_start(device_t dev, struct twsi_softc *sc, int32_t mask,
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u_char slave, int timeout)
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{
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int read_access, iflg_set = 0;
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uint32_t status;
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mtx_assert(&sc->mutex, MA_OWNED);
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if (mask == TWSI_STATUS_RPTD_START)
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/* read IFLG to know if it should be cleared later; from NBSD */
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iflg_set = TWSI_READ(sc, sc->reg_control) & TWSI_CONTROL_IFLG;
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twsi_control_set(sc, TWSI_CONTROL_START);
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if (mask == TWSI_STATUS_RPTD_START && iflg_set) {
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debugf("IFLG set, clearing\n");
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twsi_clear_iflg(sc);
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}
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/*
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* Without this delay we timeout checking IFLG if the timeout is 0.
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* NBSD driver always waits here too.
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*/
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DELAY(1000);
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if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) {
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debugf("timeout sending %sSTART condition\n",
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mask == TWSI_STATUS_START ? "" : "repeated ");
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return (IIC_ETIMEOUT);
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}
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status = TWSI_READ(sc, sc->reg_status);
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if (status != mask) {
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debugf("wrong status (%02x) after sending %sSTART condition\n",
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status, mask == TWSI_STATUS_START ? "" : "repeated ");
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return (IIC_ESTATUS);
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}
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TWSI_WRITE(sc, sc->reg_data, slave);
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twsi_clear_iflg(sc);
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DELAY(1000);
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if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) {
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debugf("timeout sending slave address\n");
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return (IIC_ETIMEOUT);
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}
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read_access = (slave & 0x1) ? 1 : 0;
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status = TWSI_READ(sc, sc->reg_status);
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if (status != (read_access ?
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TWSI_STATUS_ADDR_R_ACK : TWSI_STATUS_ADDR_W_ACK)) {
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debugf("no ACK (status: %02x) after sending slave address\n",
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status);
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return (IIC_ENOACK);
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}
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return (IIC_NOERR);
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}
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/*
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* Only slave mode supported, disregard [old]addr
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*/
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static int
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twsi_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
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{
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struct twsi_softc *sc;
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uint32_t param;
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sc = device_get_softc(dev);
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switch (speed) {
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case IIC_SLOW:
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case IIC_FAST:
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param = sc->baud_rate[speed].param;
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break;
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case IIC_FASTEST:
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case IIC_UNKNOWN:
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default:
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param = sc->baud_rate[IIC_FAST].param;
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break;
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}
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mtx_lock(&sc->mutex);
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TWSI_WRITE(sc, sc->reg_soft_reset, 0x0);
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DELAY(2000);
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TWSI_WRITE(sc, sc->reg_baud_rate, param);
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TWSI_WRITE(sc, sc->reg_control, TWSI_CONTROL_TWSIEN);
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DELAY(1000);
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mtx_unlock(&sc->mutex);
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return (0);
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}
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static int
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twsi_stop(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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mtx_lock(&sc->mutex);
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twsi_control_clear(sc, TWSI_CONTROL_ACK);
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twsi_control_set(sc, TWSI_CONTROL_STOP);
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twsi_clear_iflg(sc);
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DELAY(1000);
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mtx_unlock(&sc->mutex);
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return (IIC_NOERR);
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}
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/*
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* timeout is given in us
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*/
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static int
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twsi_repeated_start(device_t dev, u_char slave, int timeout)
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{
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struct twsi_softc *sc;
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int rv;
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sc = device_get_softc(dev);
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mtx_lock(&sc->mutex);
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rv = twsi_locked_start(dev, sc, TWSI_STATUS_RPTD_START, slave,
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timeout);
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mtx_unlock(&sc->mutex);
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if (rv) {
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twsi_stop(dev);
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return (rv);
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} else
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return (IIC_NOERR);
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}
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/*
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* timeout is given in us
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*/
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static int
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twsi_start(device_t dev, u_char slave, int timeout)
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{
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struct twsi_softc *sc;
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int rv;
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sc = device_get_softc(dev);
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mtx_lock(&sc->mutex);
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rv = twsi_locked_start(dev, sc, TWSI_STATUS_START, slave, timeout);
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mtx_unlock(&sc->mutex);
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if (rv) {
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twsi_stop(dev);
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return (rv);
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} else
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return (IIC_NOERR);
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}
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static int
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twsi_read(device_t dev, char *buf, int len, int *read, int last, int delay)
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{
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struct twsi_softc *sc;
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uint32_t status;
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int last_byte, rv;
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sc = device_get_softc(dev);
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mtx_lock(&sc->mutex);
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*read = 0;
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while (*read < len) {
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/*
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* Check if we are reading last byte of the last buffer,
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* do not send ACK then, per I2C specs
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*/
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last_byte = ((*read == len - 1) && last) ? 1 : 0;
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if (last_byte)
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twsi_control_clear(sc, TWSI_CONTROL_ACK);
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else
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twsi_control_set(sc, TWSI_CONTROL_ACK);
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twsi_clear_iflg(sc);
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DELAY(1000);
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if (twsi_poll_ctrl(sc, delay, TWSI_CONTROL_IFLG)) {
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debugf("timeout reading data\n");
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rv = IIC_ETIMEOUT;
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goto out;
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}
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status = TWSI_READ(sc, sc->reg_status);
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if (status != (last_byte ?
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TWSI_STATUS_DATA_RD_NOACK : TWSI_STATUS_DATA_RD_ACK)) {
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debugf("wrong status (%02x) while reading\n", status);
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rv = IIC_ESTATUS;
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goto out;
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}
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*buf++ = TWSI_READ(sc, sc->reg_data);
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(*read)++;
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}
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rv = IIC_NOERR;
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out:
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mtx_unlock(&sc->mutex);
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return (rv);
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}
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static int
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twsi_write(device_t dev, const char *buf, int len, int *sent, int timeout)
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{
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struct twsi_softc *sc;
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uint32_t status;
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int rv;
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sc = device_get_softc(dev);
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mtx_lock(&sc->mutex);
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*sent = 0;
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while (*sent < len) {
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TWSI_WRITE(sc, sc->reg_data, *buf++);
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twsi_clear_iflg(sc);
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DELAY(1000);
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if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) {
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debugf("timeout writing data\n");
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rv = IIC_ETIMEOUT;
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goto out;
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}
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status = TWSI_READ(sc, sc->reg_status);
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if (status != TWSI_STATUS_DATA_WR_ACK) {
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debugf("wrong status (%02x) while writing\n", status);
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rv = IIC_ESTATUS;
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goto out;
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}
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(*sent)++;
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}
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rv = IIC_NOERR;
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out:
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mtx_unlock(&sc->mutex);
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return (rv);
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}
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int
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twsi_attach(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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sc->dev = dev;
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mtx_init(&sc->mutex, device_get_nameunit(dev), "twsi", MTX_DEF);
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if (bus_alloc_resources(dev, res_spec, sc->res)) {
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device_printf(dev, "could not allocate resources\n");
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twsi_detach(dev);
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return (ENXIO);
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}
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/* Attach the iicbus. */
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if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
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device_printf(dev, "could not allocate iicbus instance\n");
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twsi_detach(dev);
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return (ENXIO);
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}
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bus_generic_attach(dev);
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return (0);
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}
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int
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twsi_detach(device_t dev)
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{
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struct twsi_softc *sc;
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int rv;
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sc = device_get_softc(dev);
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if ((rv = bus_generic_detach(dev)) != 0)
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return (rv);
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if (sc->iicbus != NULL)
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if ((rv = device_delete_child(dev, sc->iicbus)) != 0)
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return (rv);
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bus_release_resources(dev, res_spec, sc->res);
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mtx_destroy(&sc->mutex);
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return (0);
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}
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static device_method_t twsi_methods[] = {
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/* device interface */
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DEVMETHOD(device_detach, twsi_detach),
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/* Bus interface */
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DEVMETHOD(bus_setup_intr, bus_generic_setup_intr),
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DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
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DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource),
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DEVMETHOD(bus_release_resource, bus_generic_release_resource),
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DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
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DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
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DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource),
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DEVMETHOD(bus_set_resource, bus_generic_rl_set_resource),
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DEVMETHOD(bus_get_resource, bus_generic_rl_get_resource),
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/* iicbus interface */
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DEVMETHOD(iicbus_callback, iicbus_null_callback),
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DEVMETHOD(iicbus_repeated_start, twsi_repeated_start),
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DEVMETHOD(iicbus_start, twsi_start),
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DEVMETHOD(iicbus_stop, twsi_stop),
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DEVMETHOD(iicbus_write, twsi_write),
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DEVMETHOD(iicbus_read, twsi_read),
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DEVMETHOD(iicbus_reset, twsi_reset),
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DEVMETHOD(iicbus_transfer, iicbus_transfer_gen),
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{ 0, 0 }
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};
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DEFINE_CLASS_0(twsi, twsi_driver, twsi_methods,
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sizeof(struct twsi_softc));
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