1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/char/ds1620.c b/drivers/char/ds1620.c
new file mode 100644
index 0000000..74e9cd8
--- /dev/null
+++ b/drivers/char/ds1620.c
@@ -0,0 +1,419 @@
+/*
+ * 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/capability.h>
+#include <linux/init.h>
+#include <linux/smp_lock.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 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 int ds1620_open(struct inode *inode, struct file *file)
+{
+	cycle_kernel_lock();
+	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 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 const struct file_operations ds1620_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ds1620_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");