NetBSD/sys/arch/sh3/dev/adc.c

176 lines
4.4 KiB
C

/* $NetBSD: adc.c,v 1.3 2003/10/22 23:52:46 uwe Exp $ */
/*
* Copyright (c) 2003 Valeriy E. Ushakov
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: adc.c,v 1.3 2003/10/22 23:52:46 uwe Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#ifdef GPROF
#include <sys/gmon.h>
#endif
#include <sh3/adcreg.h>
#include <sh3/dev/adcvar.h>
#define ADC_(x) (*((volatile uint8_t *)SH7709_AD ## x))
struct adc_softc {
struct device sc_dev;
};
static int adc_match(struct device *, struct cfdata *, void *);
static void adc_attach(struct device *, struct device *, void *);
CFATTACH_DECL(adc, sizeof(struct adc_softc),
adc_match, adc_attach, NULL, NULL);
static int adc_search(struct device *, struct cfdata *, void *);
static int adc_print(void *, const char *);
static int
adc_match(struct device *parent, struct cfdata *cfp, void *aux)
{
/* REMINDER: also in 7727 and 7729 */
if ((cpu_product != CPU_PRODUCT_7709)
&& (cpu_product != CPU_PRODUCT_7709A))
return (0);
if (strcmp(cfp->cf_name, "adc") != 0)
return (0);
return (1);
}
static void
adc_attach(struct device *parent, struct device *self, void *aux)
{
/* struct adc_softc *sc = (struct adc_softc *)self; */
ADC_(CSR) = 0;
ADC_(CR) = 0;
printf("\n");
config_search(adc_search, self, NULL);
}
static int
adc_search(struct device *parent, struct cfdata *cf, void *aux)
{
if (config_match(parent, cf, NULL) > 0)
config_attach(parent, cf, NULL, adc_print);
return (0);
}
static int
adc_print(void *aux, const char *pnp)
{
return (pnp ? QUIET : UNCONF);
}
/*
* Sample specified ADC channel.
* Must be called at spltty().
*/
int
adc_sample_channel(int chan)
{
volatile uint8_t *hireg;
volatile uint8_t *loreg;
int regoff;
uint8_t csr;
int timo;
#ifdef DIAGNOSTIC
uint8_t cr;
char bits[128];
#endif
if ((chan < 0) || (chan >= 8))
return (-1);
regoff = (chan & 0x03) << 2;
hireg = (volatile uint8_t *)(SH7709_ADDRAH + regoff);
loreg = (volatile uint8_t *)(SH7709_ADDRAL + regoff);
/* the loop below typically takes 27 iterations on j680 */
timo = 300;
#ifdef DIAGNOSTIC
csr = ADC_(CSR);
if ((csr & SH7709_ADCSR_ADST) != 0) {
/* another conversion is in progress?! */
printf("adc_sample_channel(%d): CSR=%s", chan,
bitmask_snprintf(csr, SH7709_ADCSR_BITS,
bits, sizeof(bits)));
cr = ADC_(CR);
cr &= ~0x07; /* three lower bits always read as 1s */
printf(", CR=%s\n",
bitmask_snprintf(cr, SH7709_ADCR_BITS,
bits, sizeof(bits)));
return (-1);
}
#endif
/* start scanning */
ADC_(CSR) = chan | SH7709_ADCSR_ADST | SH7709_ADCSR_CKS;
do {
csr = ADC_(CSR);
if (timo-- == 0)
break;
} while ((csr & SH7709_ADCSR_ADF) == 0);
/* stop scanning */
csr &= ~(SH7709_ADCSR_ADF | SH7709_ADCSR_ADST);
ADC_(CSR) = csr;
if (timo <= 0) {
printf("adc_sample_channel(%d): timed out\n", chan);
return (-1);
}
/*
* 10 bit of data: bits [9..2] in the high register, bits
* [1..0] in the bits [7..6] of the low register.
*/
return (((*hireg << 8) | *loreg) >> 6);
}