FreeBSD/Linux Kernel Cross Reference
sys/dev/iicbus/s35390a.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND BSD-2-Clause-NetBSD
      *
      * Copyright (c) 2012 Yusuke Tanaka
      * All rights reserved.
      *
      * 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.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
     */
    
    /*-
     * Copyright (c) 2011 Frank Wille.
     * All rights reserved.
     *
     * Written by Frank Wille for The NetBSD Project.
     *
     * 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.
     *
     * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 THE FOUNDATION 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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    /*
     * Driver for Seiko Instruments S-35390A Real-time Clock
     */
    
    #include "opt_platform.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/clock.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    
    #include <dev/iicbus/iicbus.h>
    #include <dev/iicbus/iiconf.h>
    
    #ifdef FDT
    #include <dev/ofw/openfirm.h>
    #include <dev/ofw/ofw_bus.h>
    #include <dev/ofw/ofw_bus_subr.h>
    #endif
    
    #include "clock_if.h"
    #include "iicbus_if.h"
    
    #define S390_DEVNAME            "s35390a_rtc"
    #define S390_DEVCODE            0x6     /* 0110 */
    /*
     * S-35390A uses 4-bit device code + 3-bit command in the slave address
     * field.  The possible combination is 0x60-0x6f including the R/W bit.
     * 0x60 means an write access to status register 1.
     */
    #define S390_ADDR               (S390_DEVCODE << 4)
    
    /* Registers are encoded into the slave address */
    #define S390_STATUS1            (0 << 1)
    #define S390_STATUS2            (1 << 1)
    #define S390_REALTIME1          (2 << 1)
    #define S390_REALTIME2          (3 << 1)
    #define S390_INT1_1             (4 << 1)
   #define S390_INT1_2             (5 << 1)
   #define S390_CLOCKADJ           (6 << 1)
   #define S390_FREE               (7 << 1)
   
   /* Status1 bits */
   #define S390_ST1_POC            (1 << 7)
   #define S390_ST1_BLD            (1 << 6)
   #define S390_ST1_24H            (1 << 1)
   #define S390_ST1_RESET          (1 << 0)
   
   /* Status2 bits */
   #define S390_ST2_TEST           (1 << 7)
   
   /* Realtime1 data bytes */
   #define S390_RT1_NBYTES         7
   #define S390_RT1_YEAR           0
   #define S390_RT1_MONTH          1
   #define S390_RT1_DAY            2
   #define S390_RT1_WDAY           3
   #define S390_RT1_HOUR           4
   #define S390_RT1_MINUTE         5
   #define S390_RT1_SECOND         6
   
   struct s390rtc_softc {
           device_t        sc_dev;
           uint16_t        sc_addr;
   };
   
   /*
    * S-35390A interprets bits in each byte on SDA in reverse order.
    * bitreverse() reverses the bits in uint8_t.
    */
   static const uint8_t nibbletab[] = {
           /* 0x0 0000 -> 0000 */  0x0,
           /* 0x1 0001 -> 1000 */  0x8,
           /* 0x2 0010 -> 0100 */  0x4,
           /* 0x3 0011 -> 1100 */  0xc,
           /* 0x4 0100 -> 0010 */  0x2,
           /* 0x5 0101 -> 1010 */  0xa,
           /* 0x6 0110 -> 0110 */  0x6,
           /* 0x7 0111 -> 1110 */  0xe,
           /* 0x8 1000 -> 0001 */  0x1,
           /* 0x9 1001 -> 1001 */  0x9,
           /* 0xa 1010 -> 0101 */  0x5,
           /* 0xb 1011 -> 1101 */  0xd,
           /* 0xc 1100 -> 0011 */  0x3,
           /* 0xd 1101 -> 1011 */  0xb,
           /* 0xe 1110 -> 0111 */  0x7,
           /* 0xf 1111 -> 1111 */  0xf, };
   
   static uint8_t
   bitreverse(uint8_t x)
   {
   
           return (nibbletab[x & 0xf] << 4) | nibbletab[x >> 4];
   }
   
   static int
   s390rtc_read(device_t dev, uint8_t reg, uint8_t *buf, size_t len)
   {
           struct s390rtc_softc *sc = device_get_softc(dev);
           struct iic_msg msg[] = {
                   {
                           .slave = sc->sc_addr | reg,
                           .flags = IIC_M_RD,
                           .len = len,
                           .buf = buf,
                   },
           };
           int i;
           int error;
   
           error = iicbus_transfer_excl(dev, msg, 1, IIC_WAIT);
           if (error)
                   return (error);
   
           /* this chip returns each byte in reverse order */
           for (i = 0; i < len; ++i)
                   buf[i] = bitreverse(buf[i]);
   
           return (0);
   }
   
   static int
   s390rtc_write(device_t dev, uint8_t reg, uint8_t *buf, size_t len)
   {
           struct s390rtc_softc *sc = device_get_softc(dev);
           struct iic_msg msg[] = {
                   {
                           .slave = sc->sc_addr | reg,
                           .flags = IIC_M_WR,
                           .len = len,
                           .buf = buf,
                   },
           };
           int i;
   
           /* this chip expects each byte in reverse order */
           for (i = 0; i < len; ++i)
                   buf[i] = bitreverse(buf[i]);
   
           return (iicbus_transfer_excl(dev, msg, 1, IIC_WAIT));
   }
   
   static int
   s390rtc_probe(device_t dev)
   {
   
   #ifdef FDT
           if (!ofw_bus_status_okay(dev))
                   return (ENXIO);
   
           if (!ofw_bus_is_compatible(dev, "sii,s35390a"))
                   return (ENXIO);
   #else
           if (iicbus_get_addr(dev) != S390_ADDR) {
                   if (bootverbose)
                           device_printf(dev, "slave address mismatch. "
                               "(%02x != %02x)\n", iicbus_get_addr(dev),
                               S390_ADDR);
                   return (ENXIO);
           }
   #endif
           device_set_desc(dev, "Seiko Instruments S-35390A RTC");
   
           return (BUS_PROBE_DEFAULT);
   }
   
   static void
   s390rtc_start(void *arg)
   {
           device_t dev;
           uint8_t reg;
           int error;
   
           dev = arg;
   
           /* Reset the chip and turn on 24h mode, after power-off or battery. */
           error = s390rtc_read(dev, S390_STATUS1, &reg, 1);
           if (error) {
                   device_printf(dev, "%s: cannot read status1 register\n",
                        __func__);
                   return;
           }
           if (reg & (S390_ST1_POC | S390_ST1_BLD)) {
                   reg |= S390_ST1_24H | S390_ST1_RESET;
                   error = s390rtc_write(dev, S390_STATUS1, &reg, 1);
                   if (error) {
                           device_printf(dev,
                               "%s: cannot initialize\n", __func__);
                           return;
                   }
           }
   
           /* Disable the test mode, when enabled. */
           error = s390rtc_read(dev, S390_STATUS2, &reg, 1);
           if (error) {
                   device_printf(dev, "%s: cannot read status2 register\n",
                       __func__);
                   return;
           }
           if (reg & S390_ST2_TEST) {
                   reg &= ~S390_ST2_TEST;
                   error = s390rtc_write(dev, S390_STATUS2, &reg, 1);
                   if (error) {
                           device_printf(dev,
                               "%s: cannot disable the test mode\n", __func__);
                           return;
                   }
           }
   
           clock_register(dev, 1000000);   /* 1 second resolution */
   }
   
   static int
   s390rtc_attach(device_t dev)
   {
           struct s390rtc_softc *sc;
   
           sc = device_get_softc(dev);
           sc->sc_dev = dev;
           sc->sc_addr = iicbus_get_addr(dev);
   
           config_intrhook_oneshot(s390rtc_start, dev);
   
           return (0);
   }
   
   static int
   s390rtc_detach(device_t dev)
   {
   
           clock_unregister(dev);
           return (0);
   }
   
   static int
   s390rtc_gettime(device_t dev, struct timespec *ts)
   {
           uint8_t bcd[S390_RT1_NBYTES];
           struct bcd_clocktime bct;
           int error;
   
           error = s390rtc_read(dev, S390_REALTIME1, bcd, S390_RT1_NBYTES);
           if (error) {
                   device_printf(dev, "%s: cannot read realtime1 register\n",
                       __func__);
                   return (error);
           }
   
           /*
            * Convert the register values into something useable.
            */
           bct.nsec = 0;
           bct.sec  = bcd[S390_RT1_SECOND];
           bct.min  = bcd[S390_RT1_MINUTE];
           bct.hour = bcd[S390_RT1_HOUR] & 0x3f;
           bct.day  = bcd[S390_RT1_DAY];
           bct.dow  = bcd[S390_RT1_WDAY] & 0x07;
           bct.mon  = bcd[S390_RT1_MONTH];
           bct.year = bcd[S390_RT1_YEAR];
   
           clock_dbgprint_bcd(dev, CLOCK_DBG_READ, &bct); 
           return (clock_bcd_to_ts(&bct, ts, false));
   }
   
   static int
   s390rtc_settime(device_t dev, struct timespec *ts)
   {
           uint8_t bcd[S390_RT1_NBYTES];
           struct bcd_clocktime bct;
   
           clock_ts_to_bcd(ts, &bct, false);
           clock_dbgprint_bcd(dev, CLOCK_DBG_WRITE, &bct); 
   
           /*
            * Convert our time representation into something the S-xx390
            * can understand.
            */
           bcd[S390_RT1_SECOND] = bct.sec;
           bcd[S390_RT1_MINUTE] = bct.min;
           bcd[S390_RT1_HOUR]   = bct.hour;
           bcd[S390_RT1_DAY]    = bct.day;
           bcd[S390_RT1_WDAY]   = bct.dow;
           bcd[S390_RT1_MONTH]  = bct.mon;
           bcd[S390_RT1_YEAR]   = bct.year & 0xff;
   
           return (s390rtc_write(dev, S390_REALTIME1, bcd, S390_RT1_NBYTES));
   }
   
   static device_method_t s390rtc_methods[] = {
           DEVMETHOD(device_probe,         s390rtc_probe),
           DEVMETHOD(device_attach,        s390rtc_attach),
           DEVMETHOD(device_detach,        s390rtc_detach),
   
           DEVMETHOD(clock_gettime,        s390rtc_gettime),
           DEVMETHOD(clock_settime,        s390rtc_settime),
   
           DEVMETHOD_END
   };
   
   static driver_t s390rtc_driver = {
           S390_DEVNAME,
           s390rtc_methods,
           sizeof(struct s390rtc_softc),
   };
   
   DRIVER_MODULE(s35390a, iicbus, s390rtc_driver, NULL, NULL);
   MODULE_VERSION(s35390a, 1);
   MODULE_DEPEND(s35390a, iicbus, 1, 1, 1);

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