adding 1-wire driver

3a6291c1 · Grzegorz Daniluk · 53d94c0a · 3a6291c1 · 3a6291c1 · 3a6291c1
Commit 3a6291c1 authored Feb 29, 2012 by Grzegorz Daniluk
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Makefile Makefile +1 -1

onewire.c dev/onewire.c +194 -0

onewire.h include/onewire.h +15 -0

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--- a/Makefile
+++ b/Makefile
 PLATFORM = lm32

-OBJS_WRC = wrc_main.o dev/uart.o dev/endpoint.o dev/minic.o dev/pps_gen.o dev/syscon.o dev/softpll.o lib/mprintf.o monitor/monitor.o dev/ep_pfilter.o dev/dna.o
+OBJS_WRC = wrc_main.o dev/uart.o dev/endpoint.o dev/minic.o dev/pps_gen.o dev/syscon.o dev/onewire.o dev/softpll.o lib/mprintf.o monitor/monitor.o dev/ep_pfilter.o dev/dna.o

 D = ptp-noposix
 PTPD_CFLAGS  = -ffreestanding -DPTPD_FREESTANDING -DWRPC_EXTRA_SLIM -DPTPD_MSBF -DPTPD_DBG

--- a/dev/onewire.c
+++ b/dev/onewire.c
+#include <stdio.h>
+#include "board.h"
+
+#define   R_CSR  0x0
+#define   R_CDR  0x4
+
+#define   CSR_DAT_MSK  (1<<0)
+#define   CSR_RST_MSK  (1<<1)
+#define   CSR_OVD_MSK  (1<<2)
+#define   CSR_CYC_MSK  (1<<3)
+#define   CSR_PWR_MSK  (1<<4)
+#define   CSR_IRQ_MSK  (1<<6)
+#define   CSR_IEN_MSK  (1<<7)
+#define   CSR_SEL_OFS  8
+#define   CSR_SEL_MSK  (0xF<<8)
+#define   CSR_POWER_OFS  16
+#define   CSR_POWER_MSK  (0xFFFF<<16)
+#define   CDR_NOR_MSK  (0xFFFF<<0)
+#define   CDR_OVD_OFS  16
+#define   CDR_OVD_MSK  (0xFFFF<<16)
+
+
+#define CLK_DIV_NOR 175      //clock divider for normal mode
+#define CLK_DIV_OVD 124/2    //clock divider for overdrive mode
+
+static inline void ow_writel(uint32_t reg, uint32_t data)
+{
+  *(volatile uint32_t *) (BASE_ONEWIRE + reg) = data;
+}
+
+static inline uint32_t ow_readl(uint32_t reg)
+{
+  return *(volatile uint32_t *)(BASE_ONEWIRE + reg);
+}
+
+void ow_init()
+{
+  //set clock dividers for normal and overdrive mode
+  ow_writel( R_CDR, ((CLK_DIV_NOR & CDR_NOR_MSK) | (( CLK_DIV_OVD << CDR_OVD_OFS) & CDR_OVD_MSK)) );
+}
+
+static uint32_t ow_reset(uint32_t port)
+{
+  uint32_t reg, data;
+  
+  data = (  (port<<CSR_SEL_OFS) & CSR_SEL_MSK) |
+             CSR_CYC_MSK | CSR_RST_MSK;   //start cycle, rst pulse request
+  ow_writel(R_CSR, data);
+  //wait until cycle done
+  while(ow_readl(R_CSR) & CSR_CYC_MSK);
+  reg = ow_readl(R_CSR);
+  return ~reg & CSR_DAT_MSK;
+}
+
+static uint32_t slot(uint32_t port, uint32_t bit)
+{
+  uint32_t data, reg;
+  
+  data = (  (port<<CSR_SEL_OFS) & CSR_SEL_MSK) | 
+            CSR_CYC_MSK | (bit & CSR_DAT_MSK);  //start cycle, write bit
+  ow_writel(R_CSR, data);
+  //wait until cycle done
+  while( ow_readl(R_CSR) & CSR_CYC_MSK );
+  reg = ow_readl(R_CSR);
+  return reg & CSR_DAT_MSK;
+}
+
+static uint32_t ow_read_bit(uint32_t port) { return slot(port, 0x1); }
+static uint32_t ow_write_bit(uint32_t port, uint32_t bit) { return slot(port, bit); }
+
+
+uint8_t ow_read_byte(uint32_t port) 
+{
+  uint32_t data = 0, i;
+  
+  for(i=0;i<8;i++)
+    data |= ow_read_bit(port) << i;
+  return (uint8_t)data;
+}
+
+int8_t ow_write_byte(uint32_t port, uint32_t byte)
+{
+  uint32_t  data = 0;
+  uint8_t   i;
+  uint32_t  byte_old = byte;
+  
+  for (i=0;i<8;i++)
+  {
+    data |= ow_write_bit(port, (byte & 0x1)) << i;
+    byte >>= 1;
+  }
+  return byte_old == data ? 0 : -1;
+}
+
+int ow_write_block(int port, uint8_t *block, int len)
+{
+  uint32_t i;
+
+  for(i=0;i<len;i++)
+    *block++ = ow_write_byte(port, *block);
+
+  return 0;
+}
+
+int ow_read_block(int port, uint8_t *block, int len)
+{
+  uint32_t i;
+
+  for(i=0;i<len;i++)
+    *block++ = ow_read_byte(port);
+
+  return 0;
+}
+
+#define    ROM_SEARCH  0xF0
+#define    ROM_READ  0x33
+#define    ROM_MATCH  0x55
+#define    ROM_SKIP  0xCC
+#define    ROM_ALARM_SEARCH  0xEC
+
+#define    CONVERT_TEMP  0x44
+#define    WRITE_SCRATCHPAD  0x4E
+#define    READ_SCRATCHPAD  0xBE
+#define    COPY_SCRATCHPAD  0x48
+#define    RECALL_EEPROM  0xB8
+#define    READ_POWER_SUPPLY  0xB4
+
+static uint8_t ds18x_id [8];
+
+
+int8_t ds18x_read_serial(uint8_t *id)
+{
+  uint8_t i;
+  
+  if(!ow_reset(0))
+    return -1;
+  
+  if(ow_write_byte(0, ROM_READ) < 0)
+    return -1;
+  for(i=0;i<8;i++)
+  {
+    *id = ow_read_byte(0);
+    id++;
+  }
+  
+  return 0;
+}
+
+static int8_t ds18x_access(uint8_t *id)
+{
+  int i;
+  if(!ow_reset(0))
+    return -1;
+  
+  if(ow_write_byte(0, ROM_MATCH) < 0)
+    return -1;
+  for(i=0;i<8;i++)
+    if(ow_write_byte(0, id[i]) < 0)
+  	  return -1;
+
+  return 0;
+}
+
+int8_t ds18x_read_temp(uint8_t *id, int *temp_r)
+{
+  int i, temp;
+  uint8_t data[9];
+  
+  if(ds18x_access(id) < 0)
+    return -1;
+
+  ow_write_byte(0, READ_SCRATCHPAD);
+  
+  for(i=0;i<9;i++) data[i] = ow_read_byte(0);
+  
+  temp = ((int)data[1] << 8) | ((int)data[0]);
+  if(temp & 0x1000)
+    temp = -0x10000 + temp;
+  
+  ds18x_access(id);
+  ow_write_byte(0, CONVERT_TEMP);
+  
+  if(temp_r) *temp_r = temp;
+  return 0;
+}
+
+int ds18x_init()
+{
+	ow_init();
+	if(ds18x_read_serial(ds18x_id) < 0)
+		return -1;
+
+	return ds18x_read_temp(ds18x_id, NULL);
+}
--- a/include/onewire.h
+++ b/include/onewire.h
+#ifndef __ONEWIRE_H
+#define __ONEWIRE_H
+
+void ow_init();
+uint32_t ow_reset(uint32_t port);
+uint8_t ow_read_byte(uint32_t port);
+int8_t ow_write_byte(uint32_t port, uint32_t byte);
+int ow_write_block(int port, uint8_t *block, int len);
+int ow_read_block(int port, uint8_t *block, int len);
+
+int8_t ds18x_read_serial(uint8_t *id);
+int8_t ds18x_read_temp(uint8_t *id, int *temp_r);
+int ds18x_init();
+
+#endif