[J-u-boot.git] / drivers / ds1722.c


#include <common.h>

#ifdef CONFIG_DS1722

#include <ssi.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;
}

#endif
Commit	Line	Data
7a8e9bed WD	1
	2	#include <common.h>
	3
7a8e9bed WD	4	#ifdef CONFIG_DS1722
7a8e9bed WD	5
58b74b05 JCPV	6	#include <ssi.h>
58b74b05 JCPV	7
7a8e9bed WD	8	static void ds1722_select(int dev)
	9	{
	10	ssi_set_interface(4096, 0, 0, 0);
	11	ssi_chip_select(0);
	12	udelay(1);
	13	ssi_chip_select(dev);
	14	udelay(1);
	15	}
	16
	17
	18	u8 ds1722_read(int dev, int addr)
	19	{
	20	u8 res;
8bde7f77	21
7a8e9bed	22	ds1722_select(dev);
8bde7f77 WD	23
	24	ssi_tx_byte(addr);
	25	res = ssi_rx_byte();
	26
7a8e9bed	27	ssi_chip_select(0);
8bde7f77	28
7a8e9bed WD	29	return res;
	30	}
	31
	32	void ds1722_write(int dev, int addr, u8 data)
	33	{
	34	ds1722_select(dev);
8bde7f77 WD	35
	36	ssi_tx_byte(0x80\|addr);
	37	ssi_tx_byte(data);
	38
7a8e9bed WD	39	ssi_chip_select(0);
	40	}
	41
	42
	43	u16 ds1722_temp(int dev, int resolution)
	44	{
	45	static int useconds[] = {
8bde7f77	46	75000, 150000, 300000, 600000, 1200000
7a8e9bed WD	47	};
	48	char temp;
	49	u16 res;
8bde7f77 WD	50
8bde7f77 WD	51
7a8e9bed WD	52	/* set up the desired resulotion ... */
7a8e9bed WD	53	ds1722_write(dev, 0, 0xe0 \| (resolution << 1));
8bde7f77	54
7a8e9bed	55	/* wait while the chip measures the tremperature */
8bde7f77 WD	56	udelay(useconds[resolution]);
8bde7f77 WD	57
7a8e9bed	58	res = (temp = ds1722_read(dev, 2)) << 8;
8bde7f77 WD	59
8bde7f77 WD	60	if (temp < 0) {
7a8e9bed WD	61	temp = (16 - (ds1722_read(dev, 1) >> 4)) & 0x0f;
	62	} else {
	63	temp = (ds1722_read(dev, 1) >> 4);
	64	}
8bde7f77	65
7a8e9bed WD	66	switch (temp) {
	67	case 0:
	68	/* .0000 */
	69	break;
	70	case 1:
	71	/* .0625 */
	72	res \|=1;
	73	break;
	74	case 2:
	75	/* .1250 */
	76	res \|=1;
	77	break;
	78	case 3:
	79	/* .1875 */
	80	res \|=2;
	81	break;
	82	case 4:
	83	/* .2500 */
	84	res \|=3;
	85	break;
	86	case 5:
	87	/* .3125 */
	88	res \|=3;
	89	break;
	90	case 6:
	91	/* .3750 */
	92	res \|=4;
	93	break;
	94	case 7:
	95	/* .4375 */
	96	res \|=4;
	97	break;
	98	case 8:
	99	/* .5000 */
	100	res \|=5;
	101	break;
	102	case 9:
	103	/* .5625 */
	104	res \|=6;
	105	break;
	106	case 10:
	107	/* .6250 */
	108	res \|=6;
	109	break;
	110	case 11:
	111	/* .6875 */
	112	res \|=7;
	113	break;
	114	case 12:
	115	/* .7500 */
	116	res \|=8;
	117	break;
	118	case 13:
	119	/* .8125 */
	120	res \|=8;
	121	break;
	122	case 14:
	123	/* .8750 */
	124	res \|=9;
	125	break;
	126	case 15:
	127	/* .9375 */
	128	res \|=9;
	129	break;
130	}
131	return res;
8bde7f77	132
7a8e9bed WD	133	}
	134
	135	int ds1722_probe(int dev)
	136	{
	137	u16 temp = ds1722_temp(dev, DS1722_RESOLUTION_12BIT);
	138	printf("%d.%d deg C\n\n", (char)(temp >> 8), temp & 0xff);
	139	return 0;
	140	}
	141
	142	#endif