1 /* $NetBSD: adc.c,v 1.9 2008/03/27 03:16:29 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 1.9 2008/03/27 03:16:29 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 static int adc_match(device_t, cfdata_t, void *); 46 static void adc_attach(device_t, device_t, void *); 47 48 CFATTACH_DECL_NEW(adc, 0, 49 adc_match, adc_attach, NULL, NULL); 50 51 static int adc_search(device_t, cfdata_t, const int *, void *); 52 static int adc_print(void *, const char *); 53 54 55 static int 56 adc_match(device_t parent, cfdata_t cf, void *aux) 57 { 58 59 /* REMINDER: also in 7727 and 7729 */ 60 if ((cpu_product != CPU_PRODUCT_7709) 61 && (cpu_product != CPU_PRODUCT_7709A)) 62 return (0); 63 64 if (strcmp(cf->cf_name, "adc") != 0) 65 return (0); 66 67 return (1); 68 } 69 70 71 static void 72 adc_attach(device_t parent, device_t self, void *aux) 73 { 74 75 ADC_(CSR) = 0; 76 ADC_(CR) = 0; 77 78 aprint_naive("\n"); 79 aprint_normal("\n"); 80 81 config_search_ia(adc_search, self, "adc", NULL); 82 } 83 84 85 static int 86 adc_search(device_t parent, cfdata_t cf, const int *ldesc, void *aux) 87 { 88 89 if (config_match(parent, cf, NULL) > 0) 90 config_attach(parent, cf, NULL, adc_print); 91 92 return (0); 93 } 94 95 96 static int 97 adc_print(void *aux, const char *pnp) 98 { 99 100 return (pnp ? QUIET : UNCONF); 101 } 102 103 104 /* 105 * Sample specified ADC channel. 106 * Must be called at spltty(). 107 */ 108 int 109 adc_sample_channel(int chan) 110 { 111 volatile uint8_t *hireg; 112 volatile uint8_t *loreg; 113 int regoff; 114 uint8_t csr; 115 int timo; 116 #ifdef DIAGNOSTIC 117 uint8_t cr; 118 char bits[128]; 119 #endif 120 if ((chan < 0) || (chan >= 8)) 121 return (-1); 122 123 regoff = (chan & 0x03) << 2; 124 hireg = (volatile uint8_t *)(SH7709_ADDRAH + regoff); 125 loreg = (volatile uint8_t *)(SH7709_ADDRAL + regoff); 126 127 /* the loop below typically takes 27 iterations on j680 */ 128 timo = 300; 129 130 #ifdef DIAGNOSTIC 131 csr = ADC_(CSR); 132 if ((csr & SH7709_ADCSR_ADST) != 0) { 133 /* another conversion is in progress?! */ 134 printf("adc_sample_channel(%d): CSR=%s", chan, 135 bitmask_snprintf(csr, SH7709_ADCSR_BITS, 136 bits, sizeof(bits))); 137 cr = ADC_(CR); 138 cr &= ~0x07; /* three lower bits always read as 1s */ 139 printf(", CR=%s\n", 140 bitmask_snprintf(cr, SH7709_ADCR_BITS, 141 bits, sizeof(bits))); 142 return (-1); 143 } 144 #endif 145 146 /* start scanning */ 147 ADC_(CSR) = chan | SH7709_ADCSR_ADST | SH7709_ADCSR_CKS; 148 149 do { 150 csr = ADC_(CSR); 151 if (timo-- == 0) 152 break; 153 } while ((csr & SH7709_ADCSR_ADF) == 0); 154 155 /* stop scanning */ 156 csr &= ~(SH7709_ADCSR_ADF | SH7709_ADCSR_ADST); 157 ADC_(CSR) = csr; 158 159 if (timo <= 0) { 160 printf("adc_sample_channel(%d): timed out\n", chan); 161 return (-1); 162 } 163 164 /* 165 * 10 bit of data: bits [9..2] in the high register, bits 166 * [1..0] in the bits [7..6] of the low register. 167 */ 168 return (((*hireg << 8) | *loreg) >> 6); 169 } 170