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