NetBSD/sys/arch/arm/allwinner/awin_twi.c
2014-12-05 15:25:27 +00:00

211 lines
6.8 KiB
C

/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include "locators.h"
#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: awin_twi.c,v 1.6 2014/12/05 15:25:27 jmcneill Exp $");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/gttwsivar.h>
#include <arm/allwinner/awin_reg.h>
#include <arm/allwinner/awin_var.h>
#define TWI_CCR_REG 0x14
#define TWI_CCR_CLK_M __BITS(6,3)
#define TWI_CCR_CLK_N __BITS(2,0)
static int awin_twi_match(device_t, cfdata_t, void *);
static void awin_twi_attach(device_t, device_t, void *);
struct awin_twi_softc {
struct gttwsi_softc asc_sc;
void *asc_ih;
};
static int awin_twi_ports;
static const struct awin_gpio_pinset awin_twi_pinsets[] = {
[0] = { 'B', AWIN_PIO_PB_TWI0_FUNC, AWIN_PIO_PB_TWI0_PINS },
[1] = { 'B', AWIN_PIO_PB_TWI1_FUNC, AWIN_PIO_PB_TWI1_PINS },
[2] = { 'B', AWIN_PIO_PB_TWI2_FUNC, AWIN_PIO_PB_TWI2_PINS },
[3] = { 'I', AWIN_PIO_PI_TWI3_FUNC, AWIN_PIO_PI_TWI3_PINS },
[4] = { 'I', AWIN_PIO_PI_TWI4_FUNC, AWIN_PIO_PI_TWI4_PINS },
};
static const struct awin_gpio_pinset awin_twi_pinsets_a31[] = {
[0] = { 'H', AWIN_A31_PIO_PH_TWI0_FUNC, AWIN_A31_PIO_PH_TWI0_PINS },
[1] = { 'H', AWIN_A31_PIO_PH_TWI1_FUNC, AWIN_A31_PIO_PH_TWI1_PINS },
[2] = { 'H', AWIN_A31_PIO_PH_TWI2_FUNC, AWIN_A31_PIO_PH_TWI2_PINS },
[3] = { 'B', AWIN_A31_PIO_PB_TWI3_FUNC, AWIN_A31_PIO_PB_TWI3_PINS },
};
static const struct awin_gpio_pinset awin_twi_pinsets_a80[] = {
[0] = { 'H', AWIN_A80_PIO_PH_TWI0_FUNC, AWIN_A80_PIO_PH_TWI0_PINS },
[1] = { 'H', AWIN_A80_PIO_PH_TWI1_FUNC, AWIN_A80_PIO_PH_TWI1_PINS },
[2] = { 'H', AWIN_A80_PIO_PH_TWI2_FUNC, AWIN_A80_PIO_PH_TWI2_PINS },
[3] = { 'G', AWIN_A80_PIO_PG_TWI3_FUNC, AWIN_A80_PIO_PG_TWI3_PINS },
[4] = { 'B', AWIN_A80_PIO_PB_TWI4_FUNC, AWIN_A80_PIO_PB_TWI4_PINS },
};
CFATTACH_DECL_NEW(awin_twi, sizeof(struct awin_twi_softc),
awin_twi_match, awin_twi_attach, NULL, NULL);
static int
awin_twi_match(device_t parent, cfdata_t cf, void *aux)
{
struct awinio_attach_args * const aio = aux;
const struct awin_locators * const loc = &aio->aio_loc;
unsigned int port = loc->loc_port;
KASSERT(!strcmp(cf->cf_name, loc->loc_name));
KASSERT(cf->cf_loc[AWINIOCF_PORT] == AWINIOCF_PORT_DEFAULT
|| cf->cf_loc[AWINIOCF_PORT] == loc->loc_port);
KASSERT((awin_twi_ports & __BIT(loc->loc_port)) == 0);
/*
* We don't have alternative mappings so if one is requested
* fail the match.
*/
if (cf->cf_flags & 1)
return 0;
if (awin_chip_id() == AWIN_CHIP_ID_A31) {
if (!awin_gpio_pinset_available(&awin_twi_pinsets_a31[port]))
return 0;
} else if (awin_chip_id() == AWIN_CHIP_ID_A80) {
if (!awin_gpio_pinset_available(&awin_twi_pinsets_a80[port]))
return 0;
} else {
if (!awin_gpio_pinset_available(&awin_twi_pinsets[port]))
return 0;
}
return 1;
}
static void
awin_twi_attach(device_t parent, device_t self, void *aux)
{
struct awin_twi_softc * const asc = device_private(self);
struct awinio_attach_args * const aio = aux;
const struct awin_locators * const loc = &aio->aio_loc;
prop_dictionary_t cfg = device_properties(self);
bus_space_handle_t bsh;
uint32_t ccr;
awin_twi_ports |= __BIT(loc->loc_port);
/*
* Acquire the PIO pins needed for the TWI port.
*/
if (awin_chip_id() == AWIN_CHIP_ID_A31) {
awin_gpio_pinset_acquire(&awin_twi_pinsets_a31[loc->loc_port]);
} else if (awin_chip_id() == AWIN_CHIP_ID_A80) {
awin_gpio_pinset_acquire(&awin_twi_pinsets_a80[loc->loc_port]);
} else {
awin_gpio_pinset_acquire(&awin_twi_pinsets[loc->loc_port]);
}
/*
* Clock gating, soft reset
*/
if (awin_chip_id() == AWIN_CHIP_ID_A80) {
awin_reg_set_clear(aio->aio_core_bst, aio->aio_ccm_bsh,
AWIN_A80_CCU_SCLK_BUS_CLK_GATING4_REG,
AWIN_A80_CCU_SCLK_BUS_CLK_GATING4_TWI0 << loc->loc_port, 0);
awin_reg_set_clear(aio->aio_core_bst, aio->aio_ccm_bsh,
AWIN_A80_CCU_SCLK_BUS_SOFT_RST4_REG,
AWIN_A80_CCU_SCLK_BUS_SOFT_RST4_TWI0 << loc->loc_port, 0);
} else {
awin_reg_set_clear(aio->aio_core_bst, aio->aio_ccm_bsh,
AWIN_APB1_GATING_REG,
AWIN_APB_GATING1_TWI0 << loc->loc_port, 0);
if (awin_chip_id() == AWIN_CHIP_ID_A31) {
awin_reg_set_clear(aio->aio_core_bst, aio->aio_ccm_bsh,
AWIN_A31_APB2_RESET_REG,
AWIN_A31_APB2_RESET_TWI0_RST << loc->loc_port, 0);
}
}
/*
* Get a bus space handle for this TWI port.
*/
bus_space_subregion(aio->aio_core_bst, aio->aio_core_bsh,
loc->loc_offset, loc->loc_size, &bsh);
/*
* A31/A80 quirk
*/
switch (awin_chip_id()) {
case AWIN_CHIP_ID_A31:
case AWIN_CHIP_ID_A80:
prop_dictionary_set_bool(cfg, "iflg-rwc", true);
break;
}
/*
* Set clock rate to 100kHz. From the datasheet:
* For 100Khz standard speed 2Wire, CLK_N=2, CLK_M=11
* F0=48M/2^2=12Mhz, F1=F0/(10*(11+1)) = 0.1Mhz
*/
ccr = __SHIFTIN(11, TWI_CCR_CLK_M) | __SHIFTIN(2, TWI_CCR_CLK_N);
bus_space_write_4(aio->aio_core_bst, bsh, TWI_CCR_REG, ccr);
/*
* Do the MI attach
*/
gttwsi_attach_subr(self, aio->aio_core_bst, bsh);
/*
* Establish interrupt for it
*/
asc->asc_ih = intr_establish(loc->loc_intr, IPL_BIO, IST_LEVEL,
gttwsi_intr, &asc->asc_sc);
if (asc->asc_ih == NULL) {
aprint_error_dev(self, "failed to establish interrupt %d\n",
loc->loc_intr);
return;
}
aprint_normal_dev(self, "interrupting on irq %d\n", loc->loc_intr);
/*
* Configure its children
*/
gttwsi_config_children(self);
}