--- /dev/null
+/*
+ * 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 <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 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;
+}
+
+static inline void netwinder_ds1620_set_data_dir(int dir)
+{
+ nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
+}
+
+static inline void netwinder_ds1620_reset(void)
+{
+ nw_cpld_modify(CPLD_DS_ENABLE, 0);
+ nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
+}
+
+static inline void netwinder_lock(unsigned long *flags)
+{
+ raw_spin_lock_irqsave(&nw_gpio_lock, *flags);
+}
+
+static inline void netwinder_unlock(unsigned long *flags)
+{
+ raw_spin_unlock_irqrestore(&nw_gpio_lock, *flags);
+}
+
+static inline void netwinder_set_fan(int i)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&nw_gpio_lock, flags);
+ nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
+ raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
+}
+
+static inline int netwinder_get_fan(void)
+{
+ if ((system_rev & 0xf000) == 0x4000)
+ return FAN_ALWAYS_ON;
+
+ return (nw_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 int ds1620_open(struct inode *inode, struct file *file)
+{
+ return nonseekable_open(inode, file);
+}
+
+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 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;
+}
+
+static long
+ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ int ret;
+
+ mutex_lock(&ds1620_mutex);
+ ret = ds1620_ioctl(file, cmd, arg);
+ mutex_unlock(&ds1620_mutex);
+
+ return ret;
+}
+
+#ifdef THERM_USE_PROC
+static int ds1620_proc_therm_show(struct seq_file *m, void *v)
+{
+ struct therm th;
+ int temp;
+
+ ds1620_read_state(&th);
+ temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
+
+ seq_printf(m, "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 0;
+}
+
+static int ds1620_proc_therm_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, ds1620_proc_therm_show, NULL);
+}
+
+static const struct file_operations ds1620_proc_therm_fops = {
+ .open = ds1620_proc_therm_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#endif
+
+static const struct file_operations ds1620_fops = {
+ .owner = THIS_MODULE,
+ .open = ds1620_open,
+ .read = ds1620_read,
+ .unlocked_ioctl = ds1620_unlocked_ioctl,
+ .llseek = no_llseek,
+};
+
+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
+ if (!proc_create("therm", 0, NULL, &ds1620_proc_therm_fops))
+ 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");
Code Review / kvmfornfv.git / blobdiff