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      1 /*      $NetBSD: mcp23xxxgpio_i2c.c,v 1.2 2022/01/17 19:36:54 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2022 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: mcp23xxxgpio_i2c.c,v 1.2 2022/01/17 19:36:54 thorpej Exp $");
     34 
     35 /*
     36  * Driver for Microchip serial I/O expanders:
     37  *
     38  *	MCP23008	8-bit, I2C interface
     39  *	MCP23017	16-bit, I2C interface
     40  *	MCP23018	16-bit (open-drain outputs), I2C interface
     41  *
     42  * Data sheet:
     43  *
     44  *	https://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf
     45  */
     46 
     47 #include <sys/types.h>
     48 #include <sys/device.h>
     49 #include <sys/kernel.h>
     50 
     51 #include <dev/ic/mcp23xxxgpioreg.h>
     52 #include <dev/ic/mcp23xxxgpiovar.h>
     53 
     54 #include <dev/i2c/i2cvar.h>
     55 
     56 struct mcpgpio_i2c_softc {
     57 	struct mcpgpio_softc	sc_mcpgpio;
     58 
     59 	i2c_tag_t		sc_i2c;
     60 	i2c_addr_t		sc_addr;
     61 };
     62 
     63 #define	MCPGPIO_TO_I2C(sc)					\
     64 	container_of((sc), struct mcpgpio_i2c_softc, sc_mcpgpio)
     65 
     66 static const struct mcpgpio_variant mcp23008 = {
     67 	.name = "MCP23008",
     68 	.type = MCPGPIO_TYPE_23x08,
     69 };
     70 
     71 static const struct mcpgpio_variant mcp23017 = {
     72 	.name = "MCP23017",
     73 	.type = MCPGPIO_TYPE_23x17,
     74 };
     75 
     76 static const struct mcpgpio_variant mcp23018 = {
     77 	.name = "MCP23018",
     78 	.type = MCPGPIO_TYPE_23x18,
     79 };
     80 
     81 static const struct device_compatible_entry compat_data[] = {
     82 	{ .compat = "microchip,mcp23008",	.data = &mcp23008 },
     83 	{ .compat = "microchip,mcp23017",	.data = &mcp23017 },
     84 	{ .compat = "microchip,mcp23018",	.data = &mcp23018 },
     85 	DEVICE_COMPAT_EOL
     86 };
     87 
     88 static int
     89 mcpgpio_i2c_lock(struct mcpgpio_softc *sc)
     90 {
     91 	struct mcpgpio_i2c_softc *isc = MCPGPIO_TO_I2C(sc);
     92 
     93 	return iic_acquire_bus(isc->sc_i2c, 0);
     94 }
     95 
     96 static void
     97 mcpgpio_i2c_unlock(struct mcpgpio_softc *sc)
     98 {
     99 	struct mcpgpio_i2c_softc *isc = MCPGPIO_TO_I2C(sc);
    100 
    101 	iic_release_bus(isc->sc_i2c, 0);
    102 }
    103 
    104 static int
    105 mcpgpio_i2c_read(struct mcpgpio_softc *sc, unsigned int bank,
    106     uint8_t reg, uint8_t *valp)
    107 {
    108 	struct mcpgpio_i2c_softc *isc = MCPGPIO_TO_I2C(sc);
    109 
    110 	/* Only one chip per hardware address in i2c. */
    111 	KASSERT((bank & ~1U) == 0);
    112 
    113 	return iic_exec(isc->sc_i2c, I2C_OP_READ_WITH_STOP, isc->sc_addr,
    114 	    &reg, 1, valp, 1, 0);
    115 }
    116 
    117 static int
    118 mcpgpio_i2c_write(struct mcpgpio_softc *sc, unsigned int bank,
    119     uint8_t reg, uint8_t val)
    120 {
    121 	struct mcpgpio_i2c_softc *isc = MCPGPIO_TO_I2C(sc);
    122 
    123 	/* Only one chip per hardware address in i2c. */
    124 	KASSERT((bank & ~1U) == 0);
    125 
    126 	return iic_exec(isc->sc_i2c, I2C_OP_WRITE_WITH_STOP, isc->sc_addr,
    127 	    &reg, 1, &val, 1, 0);
    128 }
    129 
    130 static const struct mcpgpio_accessops mcpgpio_i2c_accessops = {
    131 	.lock	=	mcpgpio_i2c_lock,
    132 	.unlock	=	mcpgpio_i2c_unlock,
    133 	.read	=	mcpgpio_i2c_read,
    134 	.write	=	mcpgpio_i2c_write,
    135 };
    136 
    137 static int
    138 mcpgpio_i2c_match(device_t parent, cfdata_t match, void *aux)
    139 {
    140 	struct i2c_attach_args *ia = aux;
    141 	int match_result;
    142 
    143 	if (iic_use_direct_match(ia, match, compat_data, &match_result)) {
    144 		return match_result;
    145 	}
    146 	return 0;
    147 }
    148 
    149 static void
    150 mcpgpio_i2c_attach(device_t parent, device_t self, void *aux)
    151 {
    152 	struct mcpgpio_i2c_softc *isc = device_private(self);
    153 	struct mcpgpio_softc *sc = &isc->sc_mcpgpio;
    154 	struct i2c_attach_args *ia = aux;
    155 	const struct device_compatible_entry *dce;
    156 
    157 	isc->sc_i2c = ia->ia_tag;
    158 	isc->sc_addr = ia->ia_addr;
    159 
    160 	dce = iic_compatible_lookup(ia, compat_data);
    161 	KASSERT(dce != NULL);
    162 
    163 	sc->sc_dev = self;
    164 	sc->sc_variant = dce->data;
    165 	sc->sc_iocon = IOCON_SEQOP;
    166 	sc->sc_accessops = &mcpgpio_i2c_accessops;
    167 
    168 	aprint_naive("\n");
    169 	aprint_normal(": %s I/O Expander\n", sc->sc_variant->name);
    170 
    171 	mcpgpio_attach(sc);
    172 }
    173 
    174 CFATTACH_DECL_NEW(mcpgpio_i2c, sizeof(struct mcpgpio_i2c_softc),
    175     mcpgpio_i2c_match, mcpgpio_i2c_attach, NULL, NULL);
    176