1 /* $NetBSD: adc.c,v 1.6 2005/12/11 12:18:58 christos 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 1.6 2005/12/11 12:18:58 christos 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 #ifdef GPROF 39 #include <sys/gmon.h> 40 #endif 41 42 #include <sh3/adcreg.h> 43 #include <sh3/dev/adcvar.h> 44 45 #define ADC_(x) (*((volatile uint8_t *)SH7709_AD ## x)) 46 47 48 struct adc_softc { 49 struct device sc_dev; 50 }; 51 52 static int adc_match(struct device *, struct cfdata *, void *); 53 static void adc_attach(struct device *, struct device *, void *); 54 55 CFATTACH_DECL(adc, sizeof(struct adc_softc), 56 adc_match, adc_attach, NULL, NULL); 57 58 static int adc_search(struct device *, struct cfdata *, 59 const int *, void *); 60 static int adc_print(void *, const char *); 61 62 63 static int 64 adc_match(struct device *parent, struct cfdata *cfp, void *aux) 65 { 66 67 /* REMINDER: also in 7727 and 7729 */ 68 if ((cpu_product != CPU_PRODUCT_7709) 69 && (cpu_product != CPU_PRODUCT_7709A)) 70 return (0); 71 72 if (strcmp(cfp->cf_name, "adc") != 0) 73 return (0); 74 75 return (1); 76 } 77 78 79 static void 80 adc_attach(struct device *parent, struct device *self, void *aux) 81 { 82 /* struct adc_softc *sc = (struct adc_softc *)self; */ 83 84 ADC_(CSR) = 0; 85 ADC_(CR) = 0; 86 87 printf("\n"); 88 config_search_ia(adc_search, self, "adc", NULL); 89 } 90 91 92 static int 93 adc_search(struct device *parent, struct cfdata *cf, 94 const int *ldesc, void *aux) 95 { 96 97 if (config_match(parent, cf, NULL) > 0) 98 config_attach(parent, cf, NULL, adc_print); 99 100 return (0); 101 } 102 103 104 static int 105 adc_print(void *aux, const char *pnp) 106 { 107 108 return (pnp ? QUIET : UNCONF); 109 } 110 111 112 /* 113 * Sample specified ADC channel. 114 * Must be called at spltty(). 115 */ 116 int 117 adc_sample_channel(int chan) 118 { 119 volatile uint8_t *hireg; 120 volatile uint8_t *loreg; 121 int regoff; 122 uint8_t csr; 123 int timo; 124 #ifdef DIAGNOSTIC 125 uint8_t cr; 126 char bits[128]; 127 #endif 128 if ((chan < 0) || (chan >= 8)) 129 return (-1); 130 131 regoff = (chan & 0x03) << 2; 132 hireg = (volatile uint8_t *)(SH7709_ADDRAH + regoff); 133 loreg = (volatile uint8_t *)(SH7709_ADDRAL + regoff); 134 135 /* the loop below typically takes 27 iterations on j680 */ 136 timo = 300; 137 138 #ifdef DIAGNOSTIC 139 csr = ADC_(CSR); 140 if ((csr & SH7709_ADCSR_ADST) != 0) { 141 /* another conversion is in progress?! */ 142 printf("adc_sample_channel(%d): CSR=%s", chan, 143 bitmask_snprintf(csr, SH7709_ADCSR_BITS, 144 bits, sizeof(bits))); 145 cr = ADC_(CR); 146 cr &= ~0x07; /* three lower bits always read as 1s */ 147 printf(", CR=%s\n", 148 bitmask_snprintf(cr, SH7709_ADCR_BITS, 149 bits, sizeof(bits))); 150 return (-1); 151 } 152 #endif 153 154 /* start scanning */ 155 ADC_(CSR) = chan | SH7709_ADCSR_ADST | SH7709_ADCSR_CKS; 156 157 do { 158 csr = ADC_(CSR); 159 if (timo-- == 0) 160 break; 161 } while ((csr & SH7709_ADCSR_ADF) == 0); 162 163 /* stop scanning */ 164 csr &= ~(SH7709_ADCSR_ADF | SH7709_ADCSR_ADST); 165 ADC_(CSR) = csr; 166 167 if (timo <= 0) { 168 printf("adc_sample_channel(%d): timed out\n", chan); 169 return (-1); 170 } 171 172 /* 173 * 10 bit of data: bits [9..2] in the high register, bits 174 * [1..0] in the bits [7..6] of the low register. 175 */ 176 return (((*hireg << 8) | *loreg) >> 6); 177 } 178