[people/ms/u-boot.git] / drivers / hwmon / ds1722.c

#include <common.h>
#include <asm/ic/ssi.h>
#include <ds1722.h>

static void ds1722_select(int dev)
{
	ssi_set_interface(4096, 0, 0, 0);
	ssi_chip_select(0);
	udelay(1);
	ssi_chip_select(dev);
	udelay(1);
}


u8 ds1722_read(int dev, int addr)
{
	u8 res;

	ds1722_select(dev);

	ssi_tx_byte(addr);
	res = ssi_rx_byte();

	ssi_chip_select(0);

	return res;
}

void ds1722_write(int dev, int addr, u8 data)
{
	ds1722_select(dev);

	ssi_tx_byte(0x80|addr);
	ssi_tx_byte(data);

	ssi_chip_select(0);
}


u16 ds1722_temp(int dev, int resolution)
{
	static int useconds[] = {
		75000, 150000, 300000, 600000, 1200000
	};
	char temp;
	u16 res;


	/* set up the desired resulotion ... */
	ds1722_write(dev, 0, 0xe0 | (resolution << 1));

	/* wait while the chip measures the tremperature */
	udelay(useconds[resolution]);

	res = (temp = ds1722_read(dev, 2)) << 8;

	if (temp < 0) {
		temp = (16 - (ds1722_read(dev, 1) >> 4)) & 0x0f;
	} else {
		temp = (ds1722_read(dev, 1) >> 4);
	}

	switch (temp) {
	case 0:
		/* .0000 */
		break;
	case 1:
		/* .0625 */
		res |=1;
		break;
	case 2:
		/* .1250 */
		res |=1;
		break;
	case 3:
		/* .1875 */
		res |=2;
		break;
	case 4:
		/* .2500 */
		res |=3;
		break;
	case 5:
		/* .3125 */
		res |=3;
		break;
	case 6:
		/* .3750 */
		res |=4;
		break;
	case 7:
		/* .4375 */
		res |=4;
		break;
	case 8:
		/* .5000 */
		res |=5;
		break;
	case 9:
		/* .5625 */
		res |=6;
		break;
	case 10:
		/* .6250 */
		res |=6;
		break;
	case 11:
		/* .6875 */
		res |=7;
		break;
	case 12:
		/* .7500 */
		res |=8;
		break;
	case 13:
		/* .8125 */
		res |=8;
		break;
	case 14:
		/* .8750 */
		res |=9;
		break;
	case 15:
		/* .9375 */
		res |=9;
		break;
	}
	return res;

}

int ds1722_probe(int dev)
{
	u16 temp = ds1722_temp(dev, DS1722_RESOLUTION_12BIT);
	printf("%d.%d deg C\n\n", (char)(temp >> 8), temp & 0xff);
	return 0;
}
Commit	Line	Data
7a8e9bed	1	#include <common.h>
8907b8db GR	2	#include <asm/ic/ssi.h>
8907b8db GR	3	#include <ds1722.h>
58b74b05	4
7a8e9bed WD	5	static void ds1722_select(int dev)
	6	{
	7	ssi_set_interface(4096, 0, 0, 0);
	8	ssi_chip_select(0);
	9	udelay(1);
	10	ssi_chip_select(dev);
	11	udelay(1);
	12	}
	13
	14
	15	u8 ds1722_read(int dev, int addr)
	16	{
	17	u8 res;
8bde7f77	18
7a8e9bed	19	ds1722_select(dev);
8bde7f77 WD	20
	21	ssi_tx_byte(addr);
	22	res = ssi_rx_byte();
	23
7a8e9bed	24	ssi_chip_select(0);
8bde7f77	25
7a8e9bed WD	26	return res;
	27	}
	28
	29	void ds1722_write(int dev, int addr, u8 data)
	30	{
	31	ds1722_select(dev);
8bde7f77 WD	32
	33	ssi_tx_byte(0x80\|addr);
	34	ssi_tx_byte(data);
	35
7a8e9bed WD	36	ssi_chip_select(0);
	37	}
	38
	39
	40	u16 ds1722_temp(int dev, int resolution)
	41	{
	42	static int useconds[] = {
8bde7f77	43	75000, 150000, 300000, 600000, 1200000
7a8e9bed WD	44	};
	45	char temp;
	46	u16 res;
8bde7f77 WD	47
8bde7f77 WD	48
7a8e9bed WD	49	/* set up the desired resulotion ... */
7a8e9bed WD	50	ds1722_write(dev, 0, 0xe0 \| (resolution << 1));
8bde7f77	51
7a8e9bed	52	/* wait while the chip measures the tremperature */
8bde7f77 WD	53	udelay(useconds[resolution]);
8bde7f77 WD	54
7a8e9bed	55	res = (temp = ds1722_read(dev, 2)) << 8;
8bde7f77 WD	56
8bde7f77 WD	57	if (temp < 0) {
7a8e9bed WD	58	temp = (16 - (ds1722_read(dev, 1) >> 4)) & 0x0f;
	59	} else {
	60	temp = (ds1722_read(dev, 1) >> 4);
	61	}
8bde7f77	62
7a8e9bed WD	63	switch (temp) {
	64	case 0:
	65	/* .0000 */
	66	break;
	67	case 1:
	68	/* .0625 */
	69	res \|=1;
	70	break;
	71	case 2:
	72	/* .1250 */
	73	res \|=1;
	74	break;
	75	case 3:
	76	/* .1875 */
	77	res \|=2;
	78	break;
	79	case 4:
	80	/* .2500 */
	81	res \|=3;
	82	break;
	83	case 5:
	84	/* .3125 */
	85	res \|=3;
	86	break;
	87	case 6:
	88	/* .3750 */
	89	res \|=4;
	90	break;
	91	case 7:
	92	/* .4375 */
	93	res \|=4;
	94	break;
	95	case 8:
	96	/* .5000 */
	97	res \|=5;
	98	break;
	99	case 9:
	100	/* .5625 */
	101	res \|=6;
	102	break;
	103	case 10:
	104	/* .6250 */
	105	res \|=6;
	106	break;
	107	case 11:
	108	/* .6875 */
	109	res \|=7;
	110	break;
	111	case 12:
	112	/* .7500 */
	113	res \|=8;
	114	break;
	115	case 13:
	116	/* .8125 */
	117	res \|=8;
	118	break;
	119	case 14:
	120	/* .8750 */
	121	res \|=9;
	122	break;
	123	case 15:
	124	/* .9375 */
	125	res \|=9;
	126	break;
127	}
128	return res;
8bde7f77	129
7a8e9bed WD	130	}
	131
	132	int ds1722_probe(int dev)
	133	{
	134	u16 temp = ds1722_temp(dev, DS1722_RESOLUTION_12BIT);
	135	printf("%d.%d deg C\n\n", (char)(temp >> 8), temp & 0xff);
	136	return 0;
	137	}