FreeBSD/Linux Kernel Cross Reference
sys/arm/freescale/vybrid/vf_uart.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2013 Ruslan Bukin <br@bsdpad.com>
      * 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 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.
     */
    
    /*
     * Vybrid Family Universal Asynchronous Receiver/Transmitter
     * Chapter 49, Vybrid Reference Manual, Rev. 5, 07/2013
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_ddb.h"
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/conf.h>
    #include <sys/kdb.h>
    #include <machine/bus.h>
    
    #include <dev/uart/uart.h>
    #include <dev/uart/uart_cpu.h>
    #include <dev/uart/uart_cpu_fdt.h>
    #include <dev/uart/uart_bus.h>
    
    #include "uart_if.h"
    
    #define UART_BDH        0x00    /* Baud Rate Registers: High */
    #define UART_BDL        0x01    /* Baud Rate Registers: Low */
    #define UART_C1         0x02    /* Control Register 1 */
    #define UART_C2         0x03    /* Control Register 2 */
    #define UART_S1         0x04    /* Status Register 1 */
    #define UART_S2         0x05    /* Status Register 2 */
    #define UART_C3         0x06    /* Control Register 3 */
    #define UART_D          0x07    /* Data Register */
    #define UART_MA1        0x08    /* Match Address Registers 1 */
    #define UART_MA2        0x09    /* Match Address Registers 2 */
    #define UART_C4         0x0A    /* Control Register 4 */
    #define UART_C5         0x0B    /* Control Register 5 */
    #define UART_ED         0x0C    /* Extended Data Register */
    #define UART_MODEM      0x0D    /* Modem Register */
    #define UART_IR         0x0E    /* Infrared Register */
    #define UART_PFIFO      0x10    /* FIFO Parameters */
    #define UART_CFIFO      0x11    /* FIFO Control Register */
    #define UART_SFIFO      0x12    /* FIFO Status Register */
    #define UART_TWFIFO     0x13    /* FIFO Transmit Watermark */
    #define UART_TCFIFO     0x14    /* FIFO Transmit Count */
    #define UART_RWFIFO     0x15    /* FIFO Receive Watermark */
    #define UART_RCFIFO     0x16    /* FIFO Receive Count */
    #define UART_C7816      0x18    /* 7816 Control Register */
    #define UART_IE7816     0x19    /* 7816 Interrupt Enable Register */
    #define UART_IS7816     0x1A    /* 7816 Interrupt Status Register */
    #define UART_WP7816T0   0x1B    /* 7816 Wait Parameter Register */
    #define UART_WP7816T1   0x1B    /* 7816 Wait Parameter Register */
    #define UART_WN7816     0x1C    /* 7816 Wait N Register */
    #define UART_WF7816     0x1D    /* 7816 Wait FD Register */
    #define UART_ET7816     0x1E    /* 7816 Error Threshold Register */
    #define UART_TL7816     0x1F    /* 7816 Transmit Length Register */
    #define UART_C6         0x21    /* CEA709.1-B Control Register 6 */
    #define UART_PCTH       0x22    /* CEA709.1-B Packet Cycle Time Counter High */
    #define UART_PCTL       0x23    /* CEA709.1-B Packet Cycle Time Counter Low */
    #define UART_B1T        0x24    /* CEA709.1-B Beta1 Timer */
    #define UART_SDTH       0x25    /* CEA709.1-B Secondary Delay Timer High */
    #define UART_SDTL       0x26    /* CEA709.1-B Secondary Delay Timer Low */
    #define UART_PRE        0x27    /* CEA709.1-B Preamble */
    #define UART_TPL        0x28    /* CEA709.1-B Transmit Packet Length */
    #define UART_IE         0x29    /* CEA709.1-B Interrupt Enable Register */
    #define UART_WB         0x2A    /* CEA709.1-B WBASE */
    #define UART_S3         0x2B    /* CEA709.1-B Status Register */
    #define UART_S4         0x2C    /* CEA709.1-B Status Register */
    #define UART_RPL        0x2D    /* CEA709.1-B Received Packet Length */
    #define UART_RPREL      0x2E    /* CEA709.1-B Received Preamble Length */
    #define UART_CPW        0x2F    /* CEA709.1-B Collision Pulse Width */
    #define UART_RIDT       0x30    /* CEA709.1-B Receive Indeterminate Time */
   #define UART_TIDT       0x31    /* CEA709.1-B Transmit Indeterminate Time */
   
   #define UART_C2_TE      (1 << 3)        /* Transmitter Enable */
   #define UART_C2_TIE     (1 << 7)        /* Transmitter Interrupt Enable */
   #define UART_C2_RE      (1 << 2)        /* Receiver Enable */
   #define UART_C2_RIE     (1 << 5)        /* Receiver Interrupt Enable */
   #define UART_S1_TDRE    (1 << 7)        /* Transmit Data Register Empty Flag */
   #define UART_S1_RDRF    (1 << 5)        /* Receive Data Register Full Flag */
   #define UART_S2_LBKDIF  (1 << 7)        /* LIN Break Detect Interrupt Flag */
   
   #define UART_C4_BRFA    0x1f    /* Baud Rate Fine Adjust */
   #define UART_BDH_SBR    0x1f    /* UART Baud Rate Bits */
   
   /*
    * Low-level UART interface.
    */
   static int vf_uart_probe(struct uart_bas *bas);
   static void vf_uart_init(struct uart_bas *bas, int, int, int, int);
   static void vf_uart_term(struct uart_bas *bas);
   static void vf_uart_putc(struct uart_bas *bas, int);
   static int vf_uart_rxready(struct uart_bas *bas);
   static int vf_uart_getc(struct uart_bas *bas, struct mtx *);
   
   void uart_reinit(struct uart_softc *,int,int);
   
   static struct uart_ops uart_vybrid_ops = {
           .probe = vf_uart_probe,
           .init = vf_uart_init,
           .term = vf_uart_term,
           .putc = vf_uart_putc,
           .rxready = vf_uart_rxready,
           .getc = vf_uart_getc,
   };
   
   static int
   vf_uart_probe(struct uart_bas *bas)
   {
   
           return (0);
   }
   
   static void
   vf_uart_init(struct uart_bas *bas, int baudrate, int databits,
       int stopbits, int parity)
   {
   
   }
   
   static void
   vf_uart_term(struct uart_bas *bas)
   {
   
   }
   
   static void
   vf_uart_putc(struct uart_bas *bas, int c)
   {
   
           while (!(uart_getreg(bas, UART_S1) & UART_S1_TDRE))
                   ;
   
           uart_setreg(bas, UART_D, c);
   }
   
   static int
   vf_uart_rxready(struct uart_bas *bas)
   {
           int usr1;
   
           usr1 = uart_getreg(bas, UART_S1);
           if (usr1 & UART_S1_RDRF) {
                   return (1);
           }
   
           return (0);
   }
   
   static int
   vf_uart_getc(struct uart_bas *bas, struct mtx *hwmtx)
   {
           int c;
   
           uart_lock(hwmtx);
   
           while (!(uart_getreg(bas, UART_S1) & UART_S1_RDRF))
                   ;
   
           c = uart_getreg(bas, UART_D);
           uart_unlock(hwmtx);
   
           return (c & 0xff);
   }
   
   /*
    * High-level UART interface.
    */
   struct vf_uart_softc {
           struct uart_softc base;
   };
   
   void
   uart_reinit(struct uart_softc *sc, int clkspeed, int baud)
   {
           struct uart_bas *bas;
           int sbr;
           int brfa;
           int reg;
   
           bas = &sc->sc_bas;
           if (!bas) {
                   printf("Error: can't reconfigure bas\n");
                   return;
           }
   
           uart_setreg(bas, UART_MODEM, 0x00);
   
           /*
            * Disable transmitter and receiver
            * for a while.
            */
           reg = uart_getreg(bas, UART_C2);
           reg &= ~(UART_C2_RE | UART_C2_TE);
           uart_setreg(bas, UART_C2, 0x00);
   
           uart_setreg(bas, UART_C1, 0x00);
   
           sbr = (uint16_t) (clkspeed / (baud * 16));
           brfa = (clkspeed / baud) - (sbr * 16);
   
           reg = uart_getreg(bas, UART_BDH);
           reg &= ~UART_BDH_SBR;
           reg |= ((sbr & 0x1f00) >> 8);
           uart_setreg(bas, UART_BDH, reg);
   
           reg = sbr & 0x00ff;
           uart_setreg(bas, UART_BDL, reg);
   
           reg = uart_getreg(bas, UART_C4);
           reg &= ~UART_C4_BRFA;
           reg |= (brfa & UART_C4_BRFA);
           uart_setreg(bas, UART_C4, reg);
   
           reg = uart_getreg(bas, UART_C2);
           reg |= (UART_C2_RE | UART_C2_TE);
           uart_setreg(bas, UART_C2, reg);
   
   }
   
   static int vf_uart_bus_attach(struct uart_softc *);
   static int vf_uart_bus_detach(struct uart_softc *);
   static int vf_uart_bus_flush(struct uart_softc *, int);
   static int vf_uart_bus_getsig(struct uart_softc *);
   static int vf_uart_bus_ioctl(struct uart_softc *, int, intptr_t);
   static int vf_uart_bus_ipend(struct uart_softc *);
   static int vf_uart_bus_param(struct uart_softc *, int, int, int, int);
   static int vf_uart_bus_probe(struct uart_softc *);
   static int vf_uart_bus_receive(struct uart_softc *);
   static int vf_uart_bus_setsig(struct uart_softc *, int);
   static int vf_uart_bus_transmit(struct uart_softc *);
   
   static kobj_method_t vf_uart_methods[] = {
           KOBJMETHOD(uart_attach,         vf_uart_bus_attach),
           KOBJMETHOD(uart_detach,         vf_uart_bus_detach),
           KOBJMETHOD(uart_flush,          vf_uart_bus_flush),
           KOBJMETHOD(uart_getsig,         vf_uart_bus_getsig),
           KOBJMETHOD(uart_ioctl,          vf_uart_bus_ioctl),
           KOBJMETHOD(uart_ipend,          vf_uart_bus_ipend),
           KOBJMETHOD(uart_param,          vf_uart_bus_param),
           KOBJMETHOD(uart_probe,          vf_uart_bus_probe),
           KOBJMETHOD(uart_receive,        vf_uart_bus_receive),
           KOBJMETHOD(uart_setsig,         vf_uart_bus_setsig),
           KOBJMETHOD(uart_transmit,       vf_uart_bus_transmit),
           { 0, 0 }
   };
   
   static struct uart_class uart_vybrid_class = {
           "vybrid",
           vf_uart_methods,
           sizeof(struct vf_uart_softc),
           .uc_ops = &uart_vybrid_ops,
           .uc_range = 0x100,
           .uc_rclk = 24000000, /* TODO: get value from CCM */
           .uc_rshift = 0
   };
   
   static struct ofw_compat_data compat_data[] = {
           {"fsl,mvf600-uart",     (uintptr_t)&uart_vybrid_class},
           {NULL,                  (uintptr_t)NULL},
   };
   UART_FDT_CLASS_AND_DEVICE(compat_data);
   
   static int
   vf_uart_bus_attach(struct uart_softc *sc)
   {
           struct uart_bas *bas;
           int reg;
   
           bas = &sc->sc_bas;
   
           sc->sc_hwiflow = 0;
           sc->sc_hwoflow = 0;
   
           uart_reinit(sc, 66000000, 115200);
   
           reg = uart_getreg(bas, UART_C2);
           if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
                   reg &= ~UART_C2_RIE;
           } else {
                   reg |= UART_C2_RIE;
           }
           uart_setreg(bas, UART_C2, reg);
   
           return (0);
   }
   
   static int
   vf_uart_bus_detach(struct uart_softc *sc)
   {
   
           /* TODO */
           return (0);
   }
   
   static int
   vf_uart_bus_flush(struct uart_softc *sc, int what)
   {
   
           /* TODO */
           return (0);
   }
   
   static int
   vf_uart_bus_getsig(struct uart_softc *sc)
   {
   
           /* TODO */
           return (0);
   }
   
   static int
   vf_uart_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
   {
           struct uart_bas *bas;
           int error;
   
           bas = &sc->sc_bas;
           error = 0;
           uart_lock(sc->sc_hwmtx);
           switch (request) {
           case UART_IOCTL_BREAK:
           /* TODO */
                   break;
           case UART_IOCTL_BAUD:
           /* TODO */
                   *(int*)data = 115200;
                   break;
           default:
                   error = EINVAL;
                   break;
           }
           uart_unlock(sc->sc_hwmtx);
   
           return (error);
   }
   
   static int
   vf_uart_bus_ipend(struct uart_softc *sc)
   {
           struct uart_bas *bas;
           int ipend;
           uint32_t usr1, usr2;
           int reg;
           int sfifo;
   
           bas = &sc->sc_bas;
           ipend = 0;
   
           uart_lock(sc->sc_hwmtx);
   
           usr1 = uart_getreg(bas, UART_S1);
           usr2 = uart_getreg(bas, UART_S2);
           sfifo = uart_getreg(bas, UART_SFIFO);
   
           /* ack usr2 */
           uart_setreg(bas, UART_S2, usr2);
   
           if (usr1 & UART_S1_TDRE) {
                   reg = uart_getreg(bas, UART_C2);
                   reg &= ~(UART_C2_TIE);
                   uart_setreg(bas, UART_C2, reg);
   
                   if (sc->sc_txbusy != 0) {
                           ipend |= SER_INT_TXIDLE;
                   }
           }
   
           if (usr1 & UART_S1_RDRF) {
                   reg = uart_getreg(bas, UART_C2);
                   reg &= ~(UART_C2_RIE);
                   uart_setreg(bas, UART_C2, reg);
   
                   ipend |= SER_INT_RXREADY;
           }
   
           if (usr2 & UART_S2_LBKDIF) {
                   ipend |= SER_INT_BREAK;
           }
   
           uart_unlock(sc->sc_hwmtx);
   
           return (ipend);
   }
   
   static int
   vf_uart_bus_param(struct uart_softc *sc, int baudrate, int databits,
       int stopbits, int parity)
   {
   
           uart_lock(sc->sc_hwmtx);
           vf_uart_init(&sc->sc_bas, baudrate, databits, stopbits, parity);
           uart_unlock(sc->sc_hwmtx);
   
           return (0);
   }
   
   static int
   vf_uart_bus_probe(struct uart_softc *sc)
   {
           int error;
   
           error = vf_uart_probe(&sc->sc_bas);
           if (error)
                   return (error);
   
           sc->sc_rxfifosz = 1;
           sc->sc_txfifosz = 1;
   
           device_set_desc(sc->sc_dev, "Vybrid Family UART");
           return (0);
   }
   
   static int
   vf_uart_bus_receive(struct uart_softc *sc)
   {
           struct uart_bas *bas;
           int reg;
           int c;
   
           bas = &sc->sc_bas;
           uart_lock(sc->sc_hwmtx);
   
           /* Read FIFO */
           while (uart_getreg(bas, UART_S1) & UART_S1_RDRF) {
                   if (uart_rx_full(sc)) {
                   /* No space left in input buffer */
                           sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
                           break;
                   }
   
                   c = uart_getreg(bas, UART_D);
                   uart_rx_put(sc, c);
           }
   
           /* Reenable Data Ready interrupt */
           reg = uart_getreg(bas, UART_C2);
           reg |= (UART_C2_RIE);
           uart_setreg(bas, UART_C2, reg);
   
           uart_unlock(sc->sc_hwmtx);
           return (0);
   }
   
   static int
   vf_uart_bus_setsig(struct uart_softc *sc, int sig)
   {
           struct uart_bas *bas;
           int reg;
   
           /* TODO: implement (?) */
   
           /* XXX workaround to have working console on mount prompt */
           /* Enable RX interrupt */
           bas = &sc->sc_bas;
           if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
                   reg = uart_getreg(bas, UART_C2);
                   reg |= (UART_C2_RIE);
                   uart_setreg(bas, UART_C2, reg);
           }
   
           return (0);
   }
   
   static int
   vf_uart_bus_transmit(struct uart_softc *sc)
   {
           struct uart_bas *bas = &sc->sc_bas;
           int i;
           int reg;
   
           bas = &sc->sc_bas;
           uart_lock(sc->sc_hwmtx);
   
           /* Fill TX FIFO */
           for (i = 0; i < sc->sc_txdatasz; i++) {
                   uart_setreg(bas, UART_D, sc->sc_txbuf[i] & 0xff);
                   uart_barrier(&sc->sc_bas);
           }
   
           sc->sc_txbusy = 1;
   
           /* Call me when ready */
           reg = uart_getreg(bas, UART_C2);
           reg |= (UART_C2_TIE);
           uart_setreg(bas, UART_C2, reg);
   
           uart_unlock(sc->sc_hwmtx);
   
           return (0);
   }

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