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FMC DEL 1ns 4cha - Software
Commit 2ef5ab20 authored by Alessandro Rubini's avatar Alessandro Rubini
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onewire: cleanup, added some features, works "perfectly"

parent dc59bb4f
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Showing with 89 additions and 66 deletions
fine-delay.h
View file @ 2ef5ab20
......@@ -7,6 +7,9 @@ struct spec_fd {
unsigned char __iomem *regs;
unsigned char __iomem *ow_regs;
int acam_addr; /* cache of currently active addr */
uint8_t ds18_id[8];
unsigned long next_t;
int temp; /* scaled by 4 bits */
};
#define FD_REGS_OFFSET 0x84000
......@@ -60,7 +63,7 @@ extern void fd_pll_exit(struct spec_fd *fd);
/* Functions exported by onewire.c */
extern int fd_onewire_init(struct spec_fd *fd);
extern void fd_onewire_exit(struct spec_fd *fd);
extern int fd_read_temp(struct spec_fd *fd);
extern int fd_read_temp(struct spec_fd *fd, int verbose);
/* Functions exported by gpio.c */
extern int fd_gpio_init(struct spec_fd *fd);
......
onewire.c
View file @ 2ef5ab20
......@@ -12,6 +12,7 @@
*/
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include "fine-delay.h"
#include "hw/fd_main_regs.h"
......@@ -37,6 +38,21 @@
#define CLK_DIV_NOR (624/2)
#define CLK_DIV_OVD (124/2)
#define CMD_ROM_SEARCH 0xF0
#define CMD_ROM_READ 0x33
#define CMD_ROM_MATCH 0x55
#define CMD_ROM_SKIP 0xCC
#define CMD_ROM_ALARM_SEARCH 0xEC
#define CMD_CONVERT_TEMP 0x44
#define CMD_WRITE_SCRATCHPAD 0x4E
#define CMD_READ_SCRATCHPAD 0xBE
#define CMD_COPY_SCRATCHPAD 0x48
#define CMD_RECALL_EEPROM 0xB8
#define CMD_READ_POWER_SUPPLY 0xB4
#define FD_OW_PORT 0 /* what is this slow? */
static void ow_writel(struct spec_fd *fd, uint32_t val, unsigned long reg)
{
writel(val, fd->ow_regs + reg);
......@@ -85,23 +101,23 @@ static int write_bit(struct spec_fd *fd, int port, int bit)
static int ow_read_byte(struct spec_fd *fd, int port)
{
int data = 0, i;
int byte = 0, i;
for(i = 0; i < 8; i++)
data |= (read_bit(fd, port) << i);
return data;
byte |= (read_bit(fd, port) << i);
return byte;
}
static int ow_write_byte(struct spec_fd *fd, int port, int byte)
{
int data = 0;
int byte_old = byte, i;
int data = 0;
int i;
for (i = 0; i < 8; i++){
data |= write_bit(fd, port, (byte & 0x1)) << i;
byte >>= 1;
}
return byte_old == data ? 0 : -1;
return 0; /* success */
}
static int ow_write_block(struct spec_fd *fd, int port, uint8_t *block, int len)
......@@ -121,97 +137,101 @@ static int ow_read_block(struct spec_fd *fd, int port, uint8_t *block, int len)
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];
static int ds18x_read_serial(struct spec_fd *fd, uint8_t *id)
static int ds18x_read_serial(struct spec_fd *fd)
{
int i;
if(!ow_reset(fd, 0))
return -EIO;
ow_write_byte(fd, 0, ROM_READ);
for(i = 0; i < 8; i++) {
*id = ow_read_byte(fd, 0);
id++;
}
return 0;
ow_write_byte(fd, FD_OW_PORT, CMD_ROM_READ);
return ow_read_block(fd, FD_OW_PORT, fd->ds18_id, 8);
}
static int ds18x_access(struct spec_fd *fd, uint8_t *id)
static int ds18x_access(struct spec_fd *fd)
{
int i;
if(!ow_reset(fd, 0))
return -EIO;
if(ow_write_byte(fd, 0, ROM_MATCH) < 0)
return -EIO;
for(i = 0; i < 8; i++)
if(ow_write_byte(fd, 0, id[i]) < 0)
if (0) {
/* select the rom among several of them */
if (ow_write_byte(fd, FD_OW_PORT, CMD_ROM_MATCH) < 0)
return -EIO;
return 0;
return ow_write_block(fd, FD_OW_PORT, fd->ds18_id, 8);
} else {
/* we have one only, so skip rom */
return ow_write_byte(fd, FD_OW_PORT, CMD_ROM_SKIP);
}
}
static void __temp_command_and_next_t(struct spec_fd *fd, int cfg_reg)
{
int ms;
ds18x_access(fd);
ow_write_byte(fd, FD_OW_PORT, CMD_CONVERT_TEMP);
/* The conversion takes some time, so mark when will it be ready */
ms = 94 * ( 1 << (cfg_reg >> 5));
fd->next_t = jiffies + msecs_to_jiffies(ms);
}
static int ds18x_read_temp(struct spec_fd *fd, int *temp_r)
int fd_read_temp(struct spec_fd *fd, int verbose)
{
int i, temp;
unsigned long j;
uint8_t data[9];
if(ds18x_access(fd, ds18x_id) < 0)
return -1;
ow_write_byte(fd, 0, READ_SCRATCHPAD);
/* If first conversion, ask for it first */
if (fd->next_t == 0)
__temp_command_and_next_t(fd, 0x7f /* we ignore: max time */);
/* Wait for it to be ready: (FIXME: we need a time policy here) */
j = jiffies;
if (time_before(j, fd->next_t)) {
/* If we cannot sleep, return the previous value */
if (in_atomic())
return fd->temp;
msleep(jiffies_to_msecs(fd->next_t - j));
}
for(i = 0; i < 9; i++)
data[i] = ow_read_byte(fd, 0);
ds18x_access(fd);
ow_write_byte(fd, FD_OW_PORT, CMD_READ_SCRATCHPAD);
ow_read_block(fd, FD_OW_PORT, data, 9);
if (verbose > 1) {
pr_info("%s: Scratchpad: ", __func__);
for (i = 0; i < 9; i++)
printk("%02x%c", data[i], i == 8 ? '\n' : ':');
}
temp = ((int)data[1] << 8) | ((int)data[0]);
if(temp & 0x1000)
temp = -0x10000 + temp;
fd->temp = temp;
if (verbose) {
pr_info("%s: Temperature 0x%x (%i bits: %i.%03i)\n", __func__,
temp, 9 + (data[4] >> 5),
temp / 16, (temp & 0xf) * 1000 / 16);
}
ds18x_access(fd, ds18x_id);
ow_write_byte(fd, 0, CONVERT_TEMP);
if(temp_r) *temp_r = temp;
return 0;
}
int fd_read_temp(struct spec_fd *fd)
{
int i;
//ow_init(dev);
if(ds18x_read_serial(fd, ds18x_id) < 0)
return -EIO;
pr_debug("%s: Found DS18xx sensor: ", __func__);
for (i = 0; i < 8; i++)
printk("%02x%c", ds18x_id[i], i == 7 ? '\n' : ':');
return ds18x_read_temp(fd, NULL);
__temp_command_and_next_t(fd, data[4]); /* start next conversion */
return temp;
}
int fd_onewire_init(struct spec_fd *fd)
{
int temp;
int i;
ow_writel(fd, ((CLK_DIV_NOR & CDR_NOR_MSK)
| (( CLK_DIV_OVD << CDR_OVD_OFS) & CDR_OVD_MSK)),
R_CDR);
temp = fd_read_temp(fd);
printk("temp: %x\n", temp);
if(ds18x_read_serial(fd) < 0)
return -EIO;
pr_info("%s: Found DS18xx sensor: ", __func__);
for (i = 0; i < 8; i++)
printk("%02x%c", fd->ds18_id[i], i == 7 ? '\n' : ':');
/* read the temperature once, to ensure it works, and print it */
fd_read_temp(fd, 2);
return 0;
}
......
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