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armadillo9_iic.c revision 1.8
      1 /*	$NetBSD: armadillo9_iic.c,v 1.8 2016/02/14 19:54:20 chs Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2005 HAMAJIMA Katsuomi. All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     25  * SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __KERNEL_RCSID(0, "$NetBSD: armadillo9_iic.c,v 1.8 2016/02/14 19:54:20 chs Exp $");
     30 
     31 #include <sys/param.h>
     32 #include <sys/systm.h>
     33 #include <sys/kernel.h>
     34 #include <sys/device.h>
     35 #include <sys/mutex.h>
     36 #include <dev/i2c/i2cvar.h>
     37 #include <dev/i2c/i2c_bitbang.h>
     38 #include <arm/ep93xx/epsocvar.h>
     39 #include <arm/ep93xx/epgpiovar.h>
     40 #include <evbarm/armadillo/armadillo9var.h>
     41 
     42 #include "seeprom.h"
     43 #if NSEEPROM > 0
     44 #include <net/if.h>
     45 #include <net/if_ether.h>
     46 #include <dev/i2c/at24cxxvar.h>
     47 #endif
     48 
     49 struct armadillo9iic_softc {
     50 	struct i2c_controller	sc_i2c;
     51 	kmutex_t		sc_buslock;
     52 	int			sc_port;
     53 	int			sc_sda;
     54 	int			sc_scl;
     55 	struct epgpio_softc	*sc_gpio;
     56 };
     57 
     58 static int armadillo9iic_match(device_t, cfdata_t, void *);
     59 static void armadillo9iic_attach(device_t, device_t, void *);
     60 
     61 static int armadillo9iic_acquire_bus(void *, int);
     62 static void armadillo9iic_release_bus(void *, int);
     63 static int armadillo9iic_send_start(void *, int);
     64 static int armadillo9iic_send_stop(void *, int);
     65 static int armadillo9iic_initiate_xfer(void *, uint16_t, int);
     66 static int armadillo9iic_read_byte(void *, uint8_t *, int);
     67 static int armadillo9iic_write_byte(void *, uint8_t, int);
     68 
     69 static void armadillo9iic_bb_set_bits(void *, uint32_t);
     70 static void armadillo9iic_bb_set_dir(void *, uint32_t);
     71 static uint32_t armadillo9iic_bb_read_bits(void *);
     72 
     73 CFATTACH_DECL_NEW(armadillo9iic, sizeof(struct armadillo9iic_softc),
     74 	      armadillo9iic_match, armadillo9iic_attach, NULL, NULL);
     75 
     76 static struct i2c_bitbang_ops armadillo9iic_bbops = {
     77 	armadillo9iic_bb_set_bits,
     78 	armadillo9iic_bb_set_dir,
     79 	armadillo9iic_bb_read_bits,
     80 	{ 0, 0, 0, 0 }	/* set in attach() */
     81 };
     82 
     83 int
     84 armadillo9iic_match(device_t parent, cfdata_t cf, void *aux)
     85 {
     86 	return 2;
     87 }
     88 
     89 void
     90 armadillo9iic_attach(device_t parent, device_t self, void *aux)
     91 {
     92 	struct armadillo9iic_softc *sc = device_private(self);
     93 	struct i2cbus_attach_args iba;
     94 #if NSEEPROM > 0
     95 	struct epgpio_attach_args *ga = aux;
     96 #endif
     97 	mutex_init(&sc->sc_buslock, MUTEX_DEFAULT, IPL_NONE);
     98 
     99 	sc->sc_port = ga->ga_port;
    100 	sc->sc_sda = ga->ga_bit1;
    101 	sc->sc_scl = ga->ga_bit2;
    102 	sc->sc_gpio = (struct epgpio_softc *)parent;
    103 
    104 	armadillo9iic_bbops.ibo_bits[I2C_BIT_SDA] = (1<<sc->sc_sda);
    105 	armadillo9iic_bbops.ibo_bits[I2C_BIT_SCL] = (1<<sc->sc_scl);
    106 	armadillo9iic_bbops.ibo_bits[I2C_BIT_OUTPUT] = sc->sc_sda;
    107 	armadillo9iic_bbops.ibo_bits[I2C_BIT_INPUT] = 0;
    108 
    109 	sc->sc_i2c.ic_cookie = sc;
    110 	sc->sc_i2c.ic_acquire_bus = armadillo9iic_acquire_bus;
    111 	sc->sc_i2c.ic_release_bus = armadillo9iic_release_bus;
    112 	sc->sc_i2c.ic_send_start = armadillo9iic_send_start;
    113 	sc->sc_i2c.ic_send_stop = armadillo9iic_send_stop;
    114 	sc->sc_i2c.ic_initiate_xfer = armadillo9iic_initiate_xfer;
    115 	sc->sc_i2c.ic_read_byte = armadillo9iic_read_byte;
    116 	sc->sc_i2c.ic_write_byte = armadillo9iic_write_byte;
    117 
    118 	memset(&iba, 0, sizeof(iba));
    119 	iba.iba_tag = &sc->sc_i2c;
    120 
    121 	epgpio_in(sc->sc_gpio, sc->sc_port, sc->sc_sda);
    122 	epgpio_out(sc->sc_gpio, sc->sc_port, sc->sc_scl);
    123 	epgpio_set(sc->sc_gpio, sc->sc_port, sc->sc_scl);
    124 
    125 	printf("\n");
    126 
    127 	config_found_ia(self, "i2cbus", &iba, iicbus_print);
    128 
    129 #if NSEEPROM > 0
    130 	/* read mac address */
    131 	/* XXX This should probably be done elsewhere, earlier in bootstrap. */
    132 	if (seeprom_bootstrap_read(&sc->sc_i2c, 0x50, 0x00, 128,
    133 				   armadillo9_ethaddr, ETHER_ADDR_LEN) != 0) {
    134 		printf("%s: WARNING: unable to read MAC address from SEEPROM\n",
    135 		    device_xname(self));
    136 	}
    137 #endif
    138 }
    139 
    140 int
    141 armadillo9iic_acquire_bus(void *cookie, int flags)
    142 {
    143 	struct armadillo9iic_softc *sc = cookie;
    144 
    145 	/* XXX What should we do for the polling case? */
    146 	if (flags & I2C_F_POLL)
    147 		return 0;
    148 
    149 	mutex_enter(&sc->sc_buslock);
    150 	return 0;
    151 }
    152 
    153 void
    154 armadillo9iic_release_bus(void *cookie, int flags)
    155 {
    156 	struct armadillo9iic_softc *sc = cookie;
    157 
    158 	/* XXX See above. */
    159 	if (flags & I2C_F_POLL)
    160 		return;
    161 
    162 	mutex_exit(&sc->sc_buslock);
    163 }
    164 
    165 int
    166 armadillo9iic_send_start(void *cookie, int flags)
    167 {
    168 	return i2c_bitbang_send_start(cookie, flags, &armadillo9iic_bbops);
    169 }
    170 
    171 int
    172 armadillo9iic_send_stop(void *cookie, int flags)
    173 {
    174 	return i2c_bitbang_send_stop(cookie, flags, &armadillo9iic_bbops);
    175 }
    176 
    177 int
    178 armadillo9iic_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
    179 {
    180 	return i2c_bitbang_initiate_xfer(cookie, addr, flags,
    181 					 &armadillo9iic_bbops);
    182 }
    183 
    184 int
    185 armadillo9iic_read_byte(void *cookie, uint8_t *bytep, int flags)
    186 {
    187 	return i2c_bitbang_read_byte(cookie, bytep, flags,
    188 				     &armadillo9iic_bbops);
    189 }
    190 
    191 int
    192 armadillo9iic_write_byte(void *cookie, uint8_t byte, int flags)
    193 {
    194 	return i2c_bitbang_write_byte(cookie, byte, flags,
    195 				      &armadillo9iic_bbops);
    196 }
    197 
    198 void
    199 armadillo9iic_bb_set_bits(void *cookie, uint32_t bits)
    200 {
    201 	struct armadillo9iic_softc *sc = cookie;
    202 
    203 	if (bits & (1 << sc->sc_sda))
    204 		epgpio_set(sc->sc_gpio, sc->sc_port, sc->sc_sda);
    205 	else
    206 		epgpio_clear(sc->sc_gpio, sc->sc_port, sc->sc_sda);
    207 
    208 	if (bits & (1 << sc->sc_scl))
    209 		epgpio_set(sc->sc_gpio, sc->sc_port, sc->sc_scl);
    210 	else
    211 		epgpio_clear(sc->sc_gpio, sc->sc_port, sc->sc_scl);
    212 }
    213 
    214 void
    215 armadillo9iic_bb_set_dir(void *cookie, uint32_t bits)
    216 {
    217 	struct armadillo9iic_softc *sc = cookie;
    218 
    219 	if(bits)
    220 		epgpio_out(sc->sc_gpio, sc->sc_port, sc->sc_sda);
    221 	else
    222 		epgpio_in(sc->sc_gpio, sc->sc_port, sc->sc_sda);
    223 }
    224 
    225 uint32_t
    226 armadillo9iic_bb_read_bits(void *cookie)
    227 {
    228 	struct armadillo9iic_softc *sc = cookie;
    229 	uint32_t bits = 0;
    230 
    231 	bits |= epgpio_read(sc->sc_gpio, sc->sc_port, sc->sc_sda) << sc->sc_sda;
    232 	bits |= epgpio_read(sc->sc_gpio, sc->sc_port, sc->sc_scl) << sc->sc_scl;
    233 
    234 	return bits;
    235 }
    236