linux-imx

/*

 * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620

 *   thermometer driver (as used in the Rebel.com NetWinder)

 */

#include <linux/module.h>

#include <linux/miscdevice.h>

#include <linux/delay.h>

#include <linux/proc_fs.h>

#include <linux/seq_file.h>

#include <linux/capability.h>

#include <linux/init.h>

#include <linux/mutex.h>

​

#include <mach/hardware.h>

#include <asm/mach-types.h>

#include <linux/uaccess.h>

#include <asm/therm.h>

​

#ifdef CONFIG_PROC_FS

/* define for /proc interface */

#define THERM_USE_PROC

#endif

​

/* Definitions for DS1620 chip */

#define THERM_START_CONVERT 0xee

#define THERM_RESET     0xaf

#define THERM_READ_CONFIG   0xac

#define THERM_READ_TEMP     0xaa

#define THERM_READ_TL       0xa2

#define THERM_READ_TH       0xa1

#define THERM_WRITE_CONFIG  0x0c

#define THERM_WRITE_TL      0x02

#define THERM_WRITE_TH      0x01

​

#define CFG_CPU         2

#define CFG_1SHOT       1

​

static DEFINE_MUTEX(ds1620_mutex);

static const char *fan_state[] = { "off", "on", "on (hardwired)" };

​

/*

 * Start of NetWinder specifics

 *  Note!  We have to hold the gpio lock with IRQs disabled over the

 *  whole of our transaction to the Dallas chip, since there is a

 *  chance that the WaveArtist driver could touch these bits to

 *  enable or disable the speaker.

 */

extern unsigned int system_rev;

​

static inline void netwinder_ds1620_set_clk(int clk)

{

    nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);

}

​

static inline void netwinder_ds1620_set_data(int dat)

{

    nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);

}

​

static inline int netwinder_ds1620_get_data(void)

{

    return nw_gpio_read() & GPIO_DATA;

}