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      1 /*	$NetBSD: iomdiic.c,v 1.13 2025/09/15 13:23:01 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2003 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *      This product includes software developed for the NetBSD Project by
     20  *      Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 #include <sys/param.h>
     39 #include <sys/device.h>
     40 #include <sys/device_impl.h>	/* XXX autoconf abuse */
     41 #include <sys/kernel.h>
     42 #include <sys/systm.h>
     43 #include <sys/mutex.h>
     44 #include <sys/bus.h>
     45 #include <sys/cpu.h>
     46 
     47 #include <arm/iomd/iomdreg.h>
     48 #include <arm/iomd/iomdvar.h>
     49 
     50 #include <dev/i2c/i2cvar.h>
     51 #include <dev/i2c/i2c_bitbang.h>
     52 
     53 #include <arm/iomd/iomdiicvar.h>
     54 
     55 struct iomdiic_softc {
     56 	device_t sc_dev;
     57 	bus_space_tag_t sc_st;
     58 	bus_space_handle_t sc_sh;
     59 
     60 	struct i2c_controller sc_i2c;
     61 
     62 	/*
     63 	 * The SDA pin is open-drain, so we make it an input by
     64 	 * writing a 1 to it.
     65 	 */
     66 	uint8_t sc_iomd_iocr;
     67 };
     68 
     69 static int	iomdiic_send_start(void *, int);
     70 static int	iomdiic_send_stop(void *, int);
     71 static int	iomdiic_initiate_xfer(void *, i2c_addr_t, int);
     72 static int	iomdiic_read_byte(void *, uint8_t *, int);
     73 static int	iomdiic_write_byte(void *, uint8_t, int);
     74 
     75 #define	IOMDIIC_READ	 *(volatile uint8_t *)(IOMD_ADDRESS(IOMD_IOCR))
     76 #define	IOMDIIC_WRITE(x) *(volatile uint8_t *)(IOMD_ADDRESS(IOMD_IOCR)) = (x)
     77 
     78 #define	IOMD_IOCR_SDA		0x01
     79 #define	IOMD_IOCR_SCL		0x02
     80 
     81 static void
     82 iomdiic_bb_set_bits(void *cookie, uint32_t bits)
     83 {
     84 	struct iomdiic_softc *sc = cookie;
     85 
     86 	IOMDIIC_WRITE((IOMDIIC_READ & ~(IOMD_IOCR_SDA|IOMD_IOCR_SCL)) |
     87 	    sc->sc_iomd_iocr | bits);
     88 }
     89 
     90 static void
     91 iomdiic_bb_set_dir(void *cookie, uint32_t bits)
     92 {
     93 	struct iomdiic_softc *sc = cookie;
     94 
     95 	sc->sc_iomd_iocr = bits;
     96 }
     97 
     98 static uint32_t
     99 iomdiic_bb_read_bits(void *cookie)
    100 {
    101 
    102 	return (IOMDIIC_READ);
    103 }
    104 
    105 static const struct i2c_bitbang_ops iomdiic_bbops = {
    106 	iomdiic_bb_set_bits,
    107 	iomdiic_bb_set_dir,
    108 	iomdiic_bb_read_bits,
    109 	{
    110 		IOMD_IOCR_SDA,		/* SDA */
    111 		IOMD_IOCR_SCL,		/* SCL */
    112 		0,			/* SDA is output */
    113 		IOMD_IOCR_SDA,		/* SDA is input */
    114 	}
    115 };
    116 
    117 static int
    118 iomdiic_match(device_t parent, cfdata_t cf, void *aux)
    119 {
    120 	struct iic_attach_args *ia = aux;
    121 
    122 	if (strcmp(ia->ia_name, "iic") == 0) return 1;
    123 	return 0;
    124 }
    125 
    126 static void
    127 iomdiic_attach(device_t parent, device_t self, void *aux)
    128 {
    129 	struct iomdiic_softc *sc = device_private(self);
    130 
    131 	aprint_normal("\n");
    132 
    133 	sc->sc_dev = self;
    134 
    135 	iic_tag_init(&sc->sc_i2c);
    136 	sc->sc_i2c.ic_cookie = sc;
    137 	sc->sc_i2c.ic_send_start = iomdiic_send_start;
    138 	sc->sc_i2c.ic_send_stop = iomdiic_send_stop;
    139 	sc->sc_i2c.ic_initiate_xfer = iomdiic_initiate_xfer;
    140 	sc->sc_i2c.ic_read_byte = iomdiic_read_byte;
    141 	sc->sc_i2c.ic_write_byte = iomdiic_write_byte;
    142 
    143 	iicbus_attach(sc->sc_dev, &sc->sc_i2c);
    144 }
    145 
    146 CFATTACH_DECL_NEW(iomdiic, sizeof(struct iomdiic_softc),
    147     iomdiic_match, iomdiic_attach, NULL, NULL);
    148 
    149 i2c_tag_t
    150 iomdiic_bootstrap_cookie(void)
    151 {
    152 	static struct iomdiic_softc sc;
    153 	static struct device dev;
    154 
    155 	/* XXX Yuck. */
    156 	strcpy(dev.dv_xname, "iomdiicboot");
    157 
    158 	sc.sc_dev = &dev;
    159 
    160 	iic_tag_init(&sc.sc_i2c);
    161 	sc.sc_i2c.ic_cookie = &sc;
    162 	sc.sc_i2c.ic_send_start = iomdiic_send_start;
    163 	sc.sc_i2c.ic_send_stop = iomdiic_send_stop;
    164 	sc.sc_i2c.ic_initiate_xfer = iomdiic_initiate_xfer;
    165 	sc.sc_i2c.ic_read_byte = iomdiic_read_byte;
    166 	sc.sc_i2c.ic_write_byte = iomdiic_write_byte;
    167 
    168 	return ((void *) &sc.sc_i2c);
    169 }
    170 
    171 static int
    172 iomdiic_send_start(void *cookie, int flags)
    173 {
    174 
    175 	return (i2c_bitbang_send_start(cookie, flags, &iomdiic_bbops));
    176 }
    177 
    178 static int
    179 iomdiic_send_stop(void *cookie, int flags)
    180 {
    181 
    182 	return (i2c_bitbang_send_stop(cookie, flags, &iomdiic_bbops));
    183 }
    184 
    185 static int
    186 iomdiic_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
    187 {
    188 
    189 	return (i2c_bitbang_initiate_xfer(cookie, addr, flags, &iomdiic_bbops));
    190 }
    191 
    192 static int
    193 iomdiic_read_byte(void *cookie, uint8_t *bytep, int flags)
    194 {
    195 
    196 	return (i2c_bitbang_read_byte(cookie, bytep, flags, &iomdiic_bbops));
    197 }
    198 
    199 static int
    200 iomdiic_write_byte(void *cookie, uint8_t byte, int flags)
    201 {
    202 
    203 	return (i2c_bitbang_write_byte(cookie, byte, flags, &iomdiic_bbops));
    204 }
    205