1 /* $NetBSD: adc.c,v 1.7 2006/10/27 00:08:32 uwe Exp $ */ 2 3 /* 4 * Copyright (c) 2003 Valeriy E. Ushakov 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __KERNEL_RCSID(0, "$NetBSD: adc.c,v 1.7 2006/10/27 00:08:32 uwe Exp $"); 32 33 #include <sys/param.h> 34 #include <sys/kernel.h> 35 #include <sys/device.h> 36 #include <sys/malloc.h> 37 #include <sys/systm.h> 38 39 #include <sh3/adcreg.h> 40 #include <sh3/dev/adcvar.h> 41 42 #define ADC_(x) (*((volatile uint8_t *)SH7709_AD ## x)) 43 44 45 struct adc_softc { 46 struct device sc_dev; 47 }; 48 49 static int adc_match(struct device *, struct cfdata *, void *); 50 static void adc_attach(struct device *, struct device *, void *); 51 52 CFATTACH_DECL(adc, sizeof(struct adc_softc), 53 adc_match, adc_attach, NULL, NULL); 54 55 static int adc_search(struct device *, struct cfdata *, 56 const int *, void *); 57 static int adc_print(void *, const char *); 58 59 60 static int 61 adc_match(struct device *parent, struct cfdata *cfp, void *aux) 62 { 63 64 /* REMINDER: also in 7727 and 7729 */ 65 if ((cpu_product != CPU_PRODUCT_7709) 66 && (cpu_product != CPU_PRODUCT_7709A)) 67 return (0); 68 69 if (strcmp(cfp->cf_name, "adc") != 0) 70 return (0); 71 72 return (1); 73 } 74 75 76 static void 77 adc_attach(struct device *parent, struct device *self, void *aux) 78 { 79 /* struct adc_softc *sc = (struct adc_softc *)self; */ 80 81 ADC_(CSR) = 0; 82 ADC_(CR) = 0; 83 84 printf("\n"); 85 config_search_ia(adc_search, self, "adc", NULL); 86 } 87 88 89 static int 90 adc_search(struct device *parent, struct cfdata *cf, 91 const int *ldesc, void *aux) 92 { 93 94 if (config_match(parent, cf, NULL) > 0) 95 config_attach(parent, cf, NULL, adc_print); 96 97 return (0); 98 } 99 100 101 static int 102 adc_print(void *aux, const char *pnp) 103 { 104 105 return (pnp ? QUIET : UNCONF); 106 } 107 108 109 /* 110 * Sample specified ADC channel. 111 * Must be called at spltty(). 112 */ 113 int 114 adc_sample_channel(int chan) 115 { 116 volatile uint8_t *hireg; 117 volatile uint8_t *loreg; 118 int regoff; 119 uint8_t csr; 120 int timo; 121 #ifdef DIAGNOSTIC 122 uint8_t cr; 123 char bits[128]; 124 #endif 125 if ((chan < 0) || (chan >= 8)) 126 return (-1); 127 128 regoff = (chan & 0x03) << 2; 129 hireg = (volatile uint8_t *)(SH7709_ADDRAH + regoff); 130 loreg = (volatile uint8_t *)(SH7709_ADDRAL + regoff); 131 132 /* the loop below typically takes 27 iterations on j680 */ 133 timo = 300; 134 135 #ifdef DIAGNOSTIC 136 csr = ADC_(CSR); 137 if ((csr & SH7709_ADCSR_ADST) != 0) { 138 /* another conversion is in progress?! */ 139 printf("adc_sample_channel(%d): CSR=%s", chan, 140 bitmask_snprintf(csr, SH7709_ADCSR_BITS, 141 bits, sizeof(bits))); 142 cr = ADC_(CR); 143 cr &= ~0x07; /* three lower bits always read as 1s */ 144 printf(", CR=%s\n", 145 bitmask_snprintf(cr, SH7709_ADCR_BITS, 146 bits, sizeof(bits))); 147 return (-1); 148 } 149 #endif 150 151 /* start scanning */ 152 ADC_(CSR) = chan | SH7709_ADCSR_ADST | SH7709_ADCSR_CKS; 153 154 do { 155 csr = ADC_(CSR); 156 if (timo-- == 0) 157 break; 158 } while ((csr & SH7709_ADCSR_ADF) == 0); 159 160 /* stop scanning */ 161 csr &= ~(SH7709_ADCSR_ADF | SH7709_ADCSR_ADST); 162 ADC_(CSR) = csr; 163 164 if (timo <= 0) { 165 printf("adc_sample_channel(%d): timed out\n", chan); 166 return (-1); 167 } 168 169 /* 170 * 10 bit of data: bits [9..2] in the high register, bits 171 * [1..0] in the bits [7..6] of the low register. 172 */ 173 return (((*hireg << 8) | *loreg) >> 6); 174 } 175