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	Signed-off-by: Wolfgang Denk <wd@denx.de> [trini: Fixup common/cmd_io.c] Signed-off-by: Tom Rini <trini@ti.com>
		
			
				
	
	
		
			147 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			147 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * (C) Copyright 2007-2008
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|  * Larry Johnson, lrj@acm.org
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|  *
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|  * based on dtt/lm75.c which is ...
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|  *
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|  * (C) Copyright 2001
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|  * Bill Hunter,  Wave 7 Optics, williamhunter@mediaone.net
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|  *
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|  * SPDX-License-Identifier:	GPL-2.0+
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|  */
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| 
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| /*
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|  * National Semiconductor LM73 Temperature Sensor
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|  */
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| 
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| #include <common.h>
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| #include <i2c.h>
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| #include <dtt.h>
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| 
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| /*
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|  * Device code
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|  */
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| #define DTT_I2C_DEV_CODE 0x48	/* National Semi's LM73 device */
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| #define DTT_READ_TEMP		0x0
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| #define DTT_CONFIG		0x1
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| #define DTT_TEMP_HIGH		0x2
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| #define DTT_TEMP_LOW		0x3
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| #define DTT_CONTROL		0x4
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| #define DTT_ID			0x7
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| 
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| int dtt_read(int const sensor, int const reg)
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| {
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| 	int dlen;
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| 	uint8_t data[2];
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| 
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| 	/*
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| 	 * Validate 'reg' param and get register size.
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| 	 */
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| 	switch (reg) {
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| 	case DTT_CONFIG:
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| 	case DTT_CONTROL:
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| 		dlen = 1;
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| 		break;
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| 	case DTT_READ_TEMP:
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| 	case DTT_TEMP_HIGH:
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| 	case DTT_TEMP_LOW:
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| 	case DTT_ID:
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| 		dlen = 2;
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| 		break;
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| 	default:
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| 		return -1;
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| 	}
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| 	/*
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| 	 * Try to read the register at the calculated sensor address.
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| 	 */
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| 	if (0 !=
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| 	    i2c_read(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data, dlen))
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| 		return -1;
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| 	/*
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| 	 * Handle 2 byte result.
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| 	 */
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| 	if (2 == dlen)
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| 		return (int)((unsigned)data[0] << 8 | (unsigned)data[1]);
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| 
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| 	return (int)data[0];
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| } /* dtt_read() */
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| 
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| int dtt_write(int const sensor, int const reg, int const val)
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| {
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| 	int dlen;
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| 	uint8_t data[2];
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| 
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| 	/*
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| 	 * Validate 'reg' param and handle register size
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| 	 */
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| 	switch (reg) {
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| 	case DTT_CONFIG:
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| 	case DTT_CONTROL:
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| 		dlen = 1;
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| 		data[0] = (uint8_t) val;
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| 		break;
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| 	case DTT_TEMP_HIGH:
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| 	case DTT_TEMP_LOW:
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| 		dlen = 2;
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| 		data[0] = (uint8_t) (val >> 8);	/* MSB first */
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| 		data[1] = (uint8_t) val;
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| 		break;
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| 	default:
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| 		return -1;
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| 	}
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| 	/*
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| 	 * Write value to register at the calculated sensor address.
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| 	 */
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| 	return 0 != i2c_write(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data,
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| 			      dlen);
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| } /* dtt_write() */
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| 
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| int dtt_init_one(int const sensor)
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| {
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| 	int val;
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| 
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| 	/*
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| 	 * Validate the Identification register
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| 	 */
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| 	if (0x0190 != dtt_read(sensor, DTT_ID))
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| 		return -1;
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| 	/*
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| 	 * Setup THIGH (upper-limit) and TLOW (lower-limit) registers
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| 	 */
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| 	val = CONFIG_SYS_DTT_MAX_TEMP << 7;
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| 	if (dtt_write(sensor, DTT_TEMP_HIGH, val))
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| 		return -1;
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| 
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| 	val = CONFIG_SYS_DTT_MIN_TEMP << 7;
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| 	if (dtt_write(sensor, DTT_TEMP_LOW, val))
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| 		return -1;
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| 	/*
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| 	 * Setup configuraton register
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| 	 */
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| 	/* config = alert active low, disabled, and reset */
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| 	val = 0x64;
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| 	if (dtt_write(sensor, DTT_CONFIG, val))
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| 		return -1;
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| 	/*
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| 	 * Setup control/status register
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| 	 */
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| 	/* control = temp resolution 0.25C */
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| 	val = 0x00;
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| 	if (dtt_write(sensor, DTT_CONTROL, val))
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| 		return -1;
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| 
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| 	dtt_read(sensor, DTT_CONTROL);	/* clear temperature flags */
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| 	return 0;
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| } /* dtt_init_one() */
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| 
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| int dtt_get_temp(int const sensor)
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| {
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| 	int const ret = dtt_read(sensor, DTT_READ_TEMP);
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| 
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| 	if (ret < 0) {
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| 		printf("DTT temperature read failed.\n");
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| 		return 0;
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| 	}
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| 	return (int)((int16_t) ret + 0x0040) >> 7;
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| } /* dtt_get_temp() */
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