FreeBSD/Linux Kernel Cross Reference
sys/mips/rmi/xlr_i2c.c

     /*-
      * Copyright (c) 2003-2009 RMI Corporation
      * 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.
     * 3. Neither the name of RMI Corporation, nor the names of its contributors,
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE 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 THE 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.
     *
     * RMI_BSD */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    /*
     * I2C driver for the Palm-BK3220 I2C Host adapter on the RMI XLR.
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/module.h>
    #include <sys/mutex.h>
    #include <sys/bus.h>
    #include <sys/rman.h>
    
    
    #include <dev/iicbus/iiconf.h>
    #include <dev/iicbus/iicbus.h>
    
    #include <mips/rmi/board.h>
    #include <mips/rmi/iomap.h>
    #include <mips/include/resource.h>
    
    #include "iicbus_if.h"
    
    /* XLR I2C REGISTERS */
    #define XLR_I2C_CFG            0x00
    #define XLR_I2C_CLKDIV         0x01
    #define XLR_I2C_DEVADDR        0x02
    #define XLR_I2C_ADDR           0x03
    #define XLR_I2C_DATAOUT        0x04
    #define XLR_I2C_DATAIN         0x05
    #define XLR_I2C_STATUS         0x06
    #define XLR_I2C_STARTXFR       0x07
    #define XLR_I2C_BYTECNT        0x08
    #define XLR_I2C_HDSTATIM       0x09
    
    /* XLR I2C REGISTERS FLAGS */
    #define XLR_I2C_BUS_BUSY        0x01
    #define XLR_I2C_SDOEMPTY        0x02
    #define XLR_I2C_RXRDY           0x04
    #define XLR_I2C_ACK_ERR         0x08
    #define XLR_I2C_ARB_STARTERR    0x30
    
    /* Register Programming Values!! Change as required */
    #define XLR_I2C_CFG_ADDR        0xF8    /* 8-Bit dev Addr + POR Values */
    #define XLR_I2C_CFG_NOADDR      0xFA    /* 8-Bit reg Addr + POR Values  : No dev addr */
    #define XLR_I2C_STARTXFR_ND     0x02    /* No data , only addr */
    #define XLR_I2C_STARTXFR_RD     0x01    /* Read */
    #define XLR_I2C_STARTXFR_WR     0x00    /* Write */
    #define XLR_I2C_CLKDIV_DEF      0x14A   /* 0x00000052 */
    #define XLR_I2C_HDSTATIM_DEF    0x107   /* 0x00000000 */
    
    #define MAXTIME 0x10000
    #define ARIZONA_I2C_BUS 1
    
    static devclass_t xlr_i2c_devclass;
    
    /*
     * Device methods
     */
    static int xlr_i2c_probe(device_t);
    static int xlr_i2c_attach(device_t);
    static int xlr_i2c_detach(device_t);
    
    static int xlr_i2c_start(device_t dev, u_char slave, int timeout);
    static int xlr_i2c_stop(device_t dev);
    static int xlr_i2c_read(device_t dev, char *buf, int len, int *read, int last, int delay);
   static int xlr_i2c_write(device_t dev, const char *buf, int len, int *sent, int timeout);
   static int xlr_i2c_callback(device_t dev, int index, caddr_t data);
   static int xlr_i2c_repeated_start(device_t dev, u_char slave, int timeout);
   static int xlr_i2c_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs);
   
   struct xlr_i2c_softc {
           device_t dev;           /* Self */
           struct resource *mem_res;       /* Memory resource */
           volatile int flags;
           int sc_started;
           uint8_t i2cdev_addr;
           xlr_reg_t *iobase_i2c_regs;
           device_t iicbus;
           struct mtx sc_mtx;
   };
   
   static void  
   set_i2c_base(device_t dev)
   {
           struct xlr_i2c_softc *sc;
   
           sc = device_get_softc(dev);
           if (device_get_unit(dev) == 0)
                   sc->iobase_i2c_regs = xlr_io_mmio(XLR_IO_I2C_0_OFFSET);
           else
                   sc->iobase_i2c_regs = xlr_io_mmio(XLR_IO_I2C_1_OFFSET);
   }
   
   static void 
   xlr_i2c_dev_write(device_t dev, int reg, int value)
   {
           struct xlr_i2c_softc *sc;
   
           sc = device_get_softc(dev);
           xlr_write_reg(sc->iobase_i2c_regs, reg, value);
           return;
   }
   
   
   static int 
   xlr_i2c_dev_read(device_t dev, int reg)
   {
           uint32_t val;
           struct xlr_i2c_softc *sc;
   
           sc = device_get_softc(dev);
           val = xlr_read_reg(sc->iobase_i2c_regs, reg);
           return ((int)val);
   }
   
   
   static int
   xlr_i2c_probe(device_t dev)
   {
           device_set_desc(dev, "XLR/XLS I2C bus controller");
   
           return (0);
   }
   
   
   /*
    * We add all the devices which we know about.
    * The generic attach routine will attach them if they are alive.
    */
   static int
   xlr_i2c_attach(device_t dev)
   {
           int rid;
           struct xlr_i2c_softc *sc;
           device_t tmpd;
   
           if(device_get_unit(dev)!=ARIZONA_I2C_BUS) {
                   device_printf(dev, "unused iicbus instance\n");
                   return 0;
           }
   
           sc = device_get_softc(dev);
           set_i2c_base(dev);
   
           mtx_init(&sc->sc_mtx, "xlr_i2c", "xlr_i2c", MTX_DEF);
   
           sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
           if (sc->mem_res == NULL) {
                   printf("not able to allocate the bus resource\n");
           }
           if ((sc->iicbus = device_add_child(dev, "iicbus", -1)) == NULL) {
                   printf("could not allocate iicbus instance\n");
                   return -1;
           }
           if(xlr_board_info.xlr_i2c_device[I2C_RTC].enabled == 1) {
                   tmpd = device_add_child(sc->iicbus, "ds13rtc", 0);
                   device_set_ivars(tmpd, &xlr_board_info.xlr_i2c_device[I2C_RTC]);
           }
           if(xlr_board_info.xlr_i2c_device[I2C_THERMAL].enabled == 1) {
                   tmpd = device_add_child(sc->iicbus, "max6657", 0);
                   device_set_ivars(tmpd, &xlr_board_info.xlr_i2c_device[I2C_THERMAL]);
           }
           if(xlr_board_info.xlr_i2c_device[I2C_EEPROM].enabled == 1) {
                   tmpd = device_add_child(sc->iicbus, "at24co2n", 0);
                   device_set_ivars(tmpd, &xlr_board_info.xlr_i2c_device[I2C_EEPROM]);
           }
   
           /*
            * The old ds1374 rtc driver only handled one chip type.  The new
            * ds13rtc driver handles all ds13xx chips, but must be told the chip
            * type via hints.  XLR historically hasn't had a standard hints file,
            * so set up the hint now if it isn't already there.
            */
   #define HINTNAME "hint.ds13rtc.0.compatible"
           if (!testenv(HINTNAME))
                   kern_setenv(HINTNAME, "dallas,ds1374");
   
           bus_generic_attach(dev);
   
           return (0);
   }
   
   static int
   xlr_i2c_detach(device_t dev)
   {
           bus_generic_detach(dev);
   
           return (0);
   }
   
   static int 
   xlr_i2c_start(device_t dev, u_char slave, int timeout)
   {
           int error = 0;
           struct xlr_i2c_softc *sc;
   
           sc = device_get_softc(dev);
           mtx_lock(&sc->sc_mtx);
           sc->sc_started = 1;
           sc->i2cdev_addr = (slave >> 1);
           return error;
   
   }
   
   static int 
   xlr_i2c_stop(device_t dev)
   {
           int error = 0;
           struct xlr_i2c_softc *sc;
   
           sc = device_get_softc(dev);
           mtx_unlock(&sc->sc_mtx);
           return error;
   
   }
   
   static int 
   xlr_i2c_read(device_t dev, char *buf, int len, int *read, int last,
       int delay)
   {
           volatile uint32_t i2c_status = 0;
           int pos=0;
           int timeout = 0;
           
           xlr_i2c_dev_write(dev, XLR_I2C_CFG, XLR_I2C_CFG_NOADDR);
           xlr_i2c_dev_write(dev, XLR_I2C_BYTECNT, len);
   
   retry:
           xlr_i2c_dev_write(dev, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_RD);
   
           timeout = 0;
           while(1) {
                   if(timeout++ > MAXTIME)
                           return -1;
   
                   i2c_status = xlr_i2c_dev_read(dev, XLR_I2C_STATUS);
                   if (i2c_status & XLR_I2C_RXRDY)
                           buf[pos++] = (uint8_t) xlr_i2c_dev_read(dev, XLR_I2C_DATAIN);
   
                   /* ACKERR -- bail */
                   if (i2c_status & XLR_I2C_ACK_ERR) 
                            return -1;      /* ACK_ERROR */
   
                   /* LOST ARB or STARTERR -- repeat */
                   if (i2c_status & XLR_I2C_ARB_STARTERR)
                           goto retry;
   
                   /* Wait for busy bit to go away */
                   if (i2c_status & XLR_I2C_BUS_BUSY)
                           continue;
   
                   if (pos == len)
                           break;
           }       
           *read = pos;
           return 0;
   
   }
   
   static int 
   xlr_i2c_write(device_t dev, const char *buf, int len, int *sent, int timeout /* us */ )
   {
           volatile uint32_t i2c_status = 0x00;
           uint8_t devaddr, addr;
           struct xlr_i2c_softc *sc;
           int pos;
   
           sc = device_get_softc(dev);
   
           /* the first byte of write is  addr (of register in device) */
           addr = buf[0];
           devaddr = sc->i2cdev_addr;
           xlr_i2c_dev_write(dev, XLR_I2C_ADDR, addr);
           xlr_i2c_dev_write(dev, XLR_I2C_DEVADDR, devaddr);
           xlr_i2c_dev_write(dev, XLR_I2C_CFG, XLR_I2C_CFG_ADDR);
           xlr_i2c_dev_write(dev, XLR_I2C_BYTECNT, len - 1);
   
   retry:
           pos = 1;
           if (len == 1) /* there is no data only address */
                   xlr_i2c_dev_write(dev, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_ND);
           else {
                   xlr_i2c_dev_write(dev, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_WR);
                   xlr_i2c_dev_write(dev, XLR_I2C_DATAOUT, buf[pos]);
           }
   
           while (1) {
                   i2c_status = xlr_i2c_dev_read(dev, XLR_I2C_STATUS);
                   
                   /* sdo empty send next byte */
                   if (i2c_status & XLR_I2C_SDOEMPTY) {
                           pos++;
                           xlr_i2c_dev_write(dev, XLR_I2C_DATAOUT, buf[pos]);
                   }
   
                   /* LOST ARB or STARTERR -- repeat */
                   if (i2c_status & XLR_I2C_ARB_STARTERR) 
                           goto retry;
   
                   /* ACKERR -- bail */
                   if (i2c_status & XLR_I2C_ACK_ERR) {
                           printf("ACK ERR : exiting\n ");
                           return -1;
                   }
           
                   /* busy try again */    
                   if (i2c_status & XLR_I2C_BUS_BUSY)
                           continue;
   
                   if (pos >= len)
                           break;
           }
           *sent = len - 1;
           return 0;
   }
   
   
   
   static int
   xlr_i2c_callback(device_t dev, int index, caddr_t data)
   {
           return 0;
   }
   
   static int
   xlr_i2c_repeated_start(device_t dev, u_char slave, int timeout)
   {
           return 0;
   }
   
   /*
    * I2C bus transfer for RMI boards and devices.
    * Generic version of iicbus_transfer that calls the appropriate
    * routines to accomplish this.  See note above about acceptable
    * buffer addresses.
    */
   int
   xlr_i2c_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
   {       
           int i, error, lenread, lenwrote;
           u_char addr;
    
           addr = msgs[0].slave | LSB;
           error = xlr_i2c_start(bus, addr, 0);
           for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
                   if (msgs[i].flags & IIC_M_RD) {
                           error = xlr_i2c_read((bus), msgs[i].buf, msgs[i].len, &lenread, IIC_LAST_READ, 0);
                   }
                   else {    
                           error = xlr_i2c_write((bus), msgs[i].buf, msgs[i].len, &lenwrote, 0);
                   }
           }       
           error = xlr_i2c_stop(bus);
           return (error);
   }
   
   
   static device_method_t xlr_i2c_methods[] = {
           /* device interface */
           DEVMETHOD(device_probe, xlr_i2c_probe),
           DEVMETHOD(device_attach, xlr_i2c_attach),
           DEVMETHOD(device_detach, xlr_i2c_detach),
   
           /* iicbus interface */
           DEVMETHOD(iicbus_callback, xlr_i2c_callback),
           DEVMETHOD(iicbus_repeated_start, xlr_i2c_repeated_start),
           DEVMETHOD(iicbus_start, xlr_i2c_start),
           DEVMETHOD(iicbus_stop, xlr_i2c_stop),
           DEVMETHOD(iicbus_write, xlr_i2c_write),
           DEVMETHOD(iicbus_read, xlr_i2c_read),
           DEVMETHOD(iicbus_transfer, xlr_i2c_transfer),
           {0, 0}
   };
   
   static driver_t xlr_i2c_driver = {
           "xlr_i2c",
           xlr_i2c_methods,
           sizeof(struct xlr_i2c_softc),
   };
   
   DRIVER_MODULE(xlr_i2c, iodi, xlr_i2c_driver, xlr_i2c_devclass, 0, 0);
   DRIVER_MODULE(iicbus, xlr_i2c, iicbus_driver, iicbus_devclass, 0, 0);

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