420 lines
8.3 KiB
C
420 lines
8.3 KiB
C
/*
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* linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620
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* thermometer driver (as used in the Rebel.com NetWinder)
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*/
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#include <linux/module.h>
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#include <linux/miscdevice.h>
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#include <linux/delay.h>
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#include <linux/proc_fs.h>
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#include <linux/capability.h>
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#include <linux/init.h>
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#include <linux/smp_lock.h>
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#include <mach/hardware.h>
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#include <asm/mach-types.h>
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#include <asm/uaccess.h>
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#include <asm/therm.h>
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#ifdef CONFIG_PROC_FS
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/* define for /proc interface */
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#define THERM_USE_PROC
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#endif
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/* Definitions for DS1620 chip */
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#define THERM_START_CONVERT 0xee
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#define THERM_RESET 0xaf
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#define THERM_READ_CONFIG 0xac
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#define THERM_READ_TEMP 0xaa
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#define THERM_READ_TL 0xa2
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#define THERM_READ_TH 0xa1
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#define THERM_WRITE_CONFIG 0x0c
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#define THERM_WRITE_TL 0x02
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#define THERM_WRITE_TH 0x01
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#define CFG_CPU 2
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#define CFG_1SHOT 1
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static const char *fan_state[] = { "off", "on", "on (hardwired)" };
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/*
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* Start of NetWinder specifics
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* Note! We have to hold the gpio lock with IRQs disabled over the
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* whole of our transaction to the Dallas chip, since there is a
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* chance that the WaveArtist driver could touch these bits to
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* enable or disable the speaker.
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*/
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extern spinlock_t gpio_lock;
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extern unsigned int system_rev;
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static inline void netwinder_ds1620_set_clk(int clk)
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{
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gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
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}
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static inline void netwinder_ds1620_set_data(int dat)
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{
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gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
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}
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static inline int netwinder_ds1620_get_data(void)
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{
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return gpio_read() & GPIO_DATA;
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}
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static inline void netwinder_ds1620_set_data_dir(int dir)
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{
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gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
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}
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static inline void netwinder_ds1620_reset(void)
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{
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cpld_modify(CPLD_DS_ENABLE, 0);
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cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
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}
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static inline void netwinder_lock(unsigned long *flags)
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{
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spin_lock_irqsave(&gpio_lock, *flags);
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}
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static inline void netwinder_unlock(unsigned long *flags)
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{
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spin_unlock_irqrestore(&gpio_lock, *flags);
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}
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static inline void netwinder_set_fan(int i)
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{
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unsigned long flags;
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spin_lock_irqsave(&gpio_lock, flags);
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gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
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spin_unlock_irqrestore(&gpio_lock, flags);
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}
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static inline int netwinder_get_fan(void)
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{
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if ((system_rev & 0xf000) == 0x4000)
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return FAN_ALWAYS_ON;
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return (gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
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}
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/*
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* End of NetWinder specifics
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*/
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static void ds1620_send_bits(int nr, int value)
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{
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int i;
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for (i = 0; i < nr; i++) {
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netwinder_ds1620_set_data(value & 1);
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netwinder_ds1620_set_clk(0);
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udelay(1);
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netwinder_ds1620_set_clk(1);
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udelay(1);
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value >>= 1;
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}
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}
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static unsigned int ds1620_recv_bits(int nr)
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{
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unsigned int value = 0, mask = 1;
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int i;
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netwinder_ds1620_set_data(0);
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for (i = 0; i < nr; i++) {
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netwinder_ds1620_set_clk(0);
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udelay(1);
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if (netwinder_ds1620_get_data())
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value |= mask;
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mask <<= 1;
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netwinder_ds1620_set_clk(1);
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udelay(1);
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}
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return value;
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}
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static void ds1620_out(int cmd, int bits, int value)
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{
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unsigned long flags;
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netwinder_lock(&flags);
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netwinder_ds1620_set_clk(1);
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netwinder_ds1620_set_data_dir(0);
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netwinder_ds1620_reset();
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udelay(1);
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ds1620_send_bits(8, cmd);
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if (bits)
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ds1620_send_bits(bits, value);
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udelay(1);
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netwinder_ds1620_reset();
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netwinder_unlock(&flags);
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msleep(20);
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}
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static unsigned int ds1620_in(int cmd, int bits)
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{
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unsigned long flags;
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unsigned int value;
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netwinder_lock(&flags);
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netwinder_ds1620_set_clk(1);
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netwinder_ds1620_set_data_dir(0);
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netwinder_ds1620_reset();
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udelay(1);
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ds1620_send_bits(8, cmd);
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netwinder_ds1620_set_data_dir(1);
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value = ds1620_recv_bits(bits);
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netwinder_ds1620_reset();
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netwinder_unlock(&flags);
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return value;
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}
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static int cvt_9_to_int(unsigned int val)
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{
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if (val & 0x100)
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val |= 0xfffffe00;
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return val;
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}
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static void ds1620_write_state(struct therm *therm)
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{
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ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
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ds1620_out(THERM_WRITE_TL, 9, therm->lo);
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ds1620_out(THERM_WRITE_TH, 9, therm->hi);
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ds1620_out(THERM_START_CONVERT, 0, 0);
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}
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static void ds1620_read_state(struct therm *therm)
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{
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therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9));
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therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9));
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}
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static int ds1620_open(struct inode *inode, struct file *file)
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{
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cycle_kernel_lock();
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return nonseekable_open(inode, file);
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}
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static ssize_t
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ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
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{
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signed int cur_temp;
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signed char cur_temp_degF;
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cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1;
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/* convert to Fahrenheit, as per wdt.c */
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cur_temp_degF = (cur_temp * 9) / 5 + 32;
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if (copy_to_user(buf, &cur_temp_degF, 1))
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return -EFAULT;
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return 1;
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}
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static int
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ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
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{
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struct therm therm;
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union {
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struct therm __user *therm;
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int __user *i;
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} uarg;
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int i;
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uarg.i = (int __user *)arg;
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switch(cmd) {
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case CMD_SET_THERMOSTATE:
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case CMD_SET_THERMOSTATE2:
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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if (cmd == CMD_SET_THERMOSTATE) {
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if (get_user(therm.hi, uarg.i))
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return -EFAULT;
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therm.lo = therm.hi - 3;
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} else {
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if (copy_from_user(&therm, uarg.therm, sizeof(therm)))
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return -EFAULT;
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}
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therm.lo <<= 1;
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therm.hi <<= 1;
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ds1620_write_state(&therm);
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break;
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case CMD_GET_THERMOSTATE:
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case CMD_GET_THERMOSTATE2:
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ds1620_read_state(&therm);
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therm.lo >>= 1;
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therm.hi >>= 1;
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if (cmd == CMD_GET_THERMOSTATE) {
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if (put_user(therm.hi, uarg.i))
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return -EFAULT;
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} else {
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if (copy_to_user(uarg.therm, &therm, sizeof(therm)))
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return -EFAULT;
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}
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break;
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case CMD_GET_TEMPERATURE:
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case CMD_GET_TEMPERATURE2:
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i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
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if (cmd == CMD_GET_TEMPERATURE)
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i >>= 1;
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return put_user(i, uarg.i) ? -EFAULT : 0;
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case CMD_GET_STATUS:
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i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3;
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return put_user(i, uarg.i) ? -EFAULT : 0;
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case CMD_GET_FAN:
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i = netwinder_get_fan();
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return put_user(i, uarg.i) ? -EFAULT : 0;
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case CMD_SET_FAN:
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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if (get_user(i, uarg.i))
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return -EFAULT;
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netwinder_set_fan(i);
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break;
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default:
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return -ENOIOCTLCMD;
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}
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return 0;
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}
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#ifdef THERM_USE_PROC
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static int
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proc_therm_ds1620_read(char *buf, char **start, off_t offset,
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int len, int *eof, void *unused)
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{
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struct therm th;
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int temp;
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ds1620_read_state(&th);
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temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
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len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; "
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"temperature: %i.%i C, fan %s\n",
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th.hi >> 1, th.hi & 1 ? 5 : 0,
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th.lo >> 1, th.lo & 1 ? 5 : 0,
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temp >> 1, temp & 1 ? 5 : 0,
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fan_state[netwinder_get_fan()]);
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return len;
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}
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static struct proc_dir_entry *proc_therm_ds1620;
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#endif
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static const struct file_operations ds1620_fops = {
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.owner = THIS_MODULE,
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.open = ds1620_open,
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.read = ds1620_read,
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.ioctl = ds1620_ioctl,
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};
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static struct miscdevice ds1620_miscdev = {
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TEMP_MINOR,
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"temp",
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&ds1620_fops
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};
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static int __init ds1620_init(void)
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{
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int ret;
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struct therm th, th_start;
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if (!machine_is_netwinder())
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return -ENODEV;
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ds1620_out(THERM_RESET, 0, 0);
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ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
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ds1620_out(THERM_START_CONVERT, 0, 0);
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/*
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* Trigger the fan to start by setting
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* temperature high point low. This kicks
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* the fan into action.
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*/
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ds1620_read_state(&th);
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th_start.lo = 0;
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th_start.hi = 1;
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ds1620_write_state(&th_start);
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msleep(2000);
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ds1620_write_state(&th);
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ret = misc_register(&ds1620_miscdev);
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if (ret < 0)
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return ret;
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#ifdef THERM_USE_PROC
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proc_therm_ds1620 = create_proc_entry("therm", 0, NULL);
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if (proc_therm_ds1620)
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proc_therm_ds1620->read_proc = proc_therm_ds1620_read;
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else
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printk(KERN_ERR "therm: unable to register /proc/therm\n");
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#endif
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ds1620_read_state(&th);
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ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
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printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, "
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"current %i.%i C, fan %s.\n",
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th.hi >> 1, th.hi & 1 ? 5 : 0,
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th.lo >> 1, th.lo & 1 ? 5 : 0,
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ret >> 1, ret & 1 ? 5 : 0,
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fan_state[netwinder_get_fan()]);
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return 0;
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}
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static void __exit ds1620_exit(void)
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{
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#ifdef THERM_USE_PROC
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remove_proc_entry("therm", NULL);
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#endif
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misc_deregister(&ds1620_miscdev);
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}
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module_init(ds1620_init);
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module_exit(ds1620_exit);
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MODULE_LICENSE("GPL");
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