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424 lines
8.4 KiB
424 lines
8.4 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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/seq_file.h> |
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#include <linux/capability.h> |
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#include <linux/init.h> |
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#include <linux/mutex.h> |
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#include <mach/hardware.h> |
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#include <asm/mach-types.h> |
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#include <linux/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 DEFINE_MUTEX(ds1620_mutex); |
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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 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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nw_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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nw_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 nw_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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nw_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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nw_cpld_modify(CPLD_DS_ENABLE, 0); |
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nw_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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raw_spin_lock_irqsave(&nw_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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raw_spin_unlock_irqrestore(&nw_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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raw_spin_lock_irqsave(&nw_gpio_lock, flags); |
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nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0); |
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raw_spin_unlock_irqrestore(&nw_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 (nw_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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return stream_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 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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static long |
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ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
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{ |
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int ret; |
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mutex_lock(&ds1620_mutex); |
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ret = ds1620_ioctl(file, cmd, arg); |
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mutex_unlock(&ds1620_mutex); |
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return ret; |
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} |
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#ifdef THERM_USE_PROC |
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static int ds1620_proc_therm_show(struct seq_file *m, void *v) |
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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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seq_printf(m, "Thermostat: HI %i.%i, LOW %i.%i; 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 0; |
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} |
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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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.unlocked_ioctl = ds1620_unlocked_ioctl, |
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.llseek = no_llseek, |
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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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if (!proc_create_single("therm", 0, NULL, ds1620_proc_therm_show)) |
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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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