Ejemplo n.º 1
0
static void pca_reset(struct i2c_algo_pca_data *adap)
{
	if (adap->chip == I2C_PCA_CHIP_9665) {
		/* Ignore the reset function from the module,
		 * we can use the parallel bus reset.
		 */
		pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
		pca_outw(adap, I2C_PCA_IND, 0xA5);
		pca_outw(adap, I2C_PCA_IND, 0x5A);
	} else {
		adap->reset_chip(adap->data);
	}
}
static int pca_tx_byte(struct i2c_algo_pca_data *adap,
		       __u8 b)
{
	int sta = pca_get_con(adap);
	DEB2("=== WRITE %#04x\n", b);
	pca_outw(adap, I2C_PCA_DAT, b);

	sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
	pca_set_con(adap, sta);

	return pca_wait(adap);
}
static unsigned int pca_probe_chip(struct i2c_adapter *adap)
{
	struct i2c_algo_pca_data *pca_data = adap->algo_data;
	/* The trick here is to check if there is an indirect register
	 * available. If there is one, we will read the value we first
	 * wrote on I2C_PCA_IADR. Otherwise, we will read the last value
	 * we wrote on I2C_PCA_ADR
	 */
	pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
	pca_outw(pca_data, I2C_PCA_IND, 0xAA);
	pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ITO);
	pca_outw(pca_data, I2C_PCA_IND, 0x00);
	pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
	if (pca_inw(pca_data, I2C_PCA_IND) == 0xAA) {
		printk(KERN_INFO "%s: PCA9665 detected.\n", adap->name);
		return I2C_PCA_CHIP_9665;
	} else {
		printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name);
		return I2C_PCA_CHIP_9564;
	}
}
Ejemplo n.º 4
0
static int pca_init(struct i2c_algo_pca_data *adap)
{
	static int freqs[] = {330,288,217,146,88,59,44,36};
	int own, clock;

	own = pca_own(adap);
	clock = pca_clock(adap);
	DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
	DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);

	pca_outw(adap, I2C_PCA_ADR, own << 1);

	pca_set_con(adap, I2C_PCA_CON_ENSIO | clock);
	udelay(500); /* 500 µs for oscilator to stabilise */

	return 0;
}
static int pca_address(struct i2c_algo_pca_data *adap,
		       struct i2c_msg *msg)
{
	int sta = pca_get_con(adap);
	int addr;

	addr = ((0x7f & msg->addr) << 1);
	if (msg->flags & I2C_M_RD)
		addr |= 1;
	DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
	     msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);

	pca_outw(adap, I2C_PCA_DAT, addr);

	sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
	pca_set_con(adap, sta);

	return pca_wait(adap);
}
static int pca_init(struct i2c_adapter *adap)
{
	struct i2c_algo_pca_data *pca_data = adap->algo_data;

	adap->algo = &pca_algo;

	if (pca_probe_chip(adap) == I2C_PCA_CHIP_9564) {
		static int freqs[] = {330, 288, 217, 146, 88, 59, 44, 36};
		int clock;

		if (pca_data->i2c_clock > 7) {
			switch (pca_data->i2c_clock) {
			case 330000:
				pca_data->i2c_clock = I2C_PCA_CON_330kHz;
				break;
			case 288000:
				pca_data->i2c_clock = I2C_PCA_CON_288kHz;
				break;
			case 217000:
				pca_data->i2c_clock = I2C_PCA_CON_217kHz;
				break;
			case 146000:
				pca_data->i2c_clock = I2C_PCA_CON_146kHz;
				break;
			case 88000:
				pca_data->i2c_clock = I2C_PCA_CON_88kHz;
				break;
			case 59000:
				pca_data->i2c_clock = I2C_PCA_CON_59kHz;
				break;
			case 44000:
				pca_data->i2c_clock = I2C_PCA_CON_44kHz;
				break;
			case 36000:
				pca_data->i2c_clock = I2C_PCA_CON_36kHz;
				break;
			default:
				printk(KERN_WARNING
					"%s: Invalid I2C clock speed selected."
					" Using default 59kHz.\n", adap->name);
			pca_data->i2c_clock = I2C_PCA_CON_59kHz;
			}
		} else {
			printk(KERN_WARNING "%s: "
				"Choosing the clock frequency based on "
				"index is deprecated."
				" Use the nominal frequency.\n", adap->name);
		}

		pca_reset(pca_data);

		clock = pca_clock(pca_data);
		printk(KERN_INFO "%s: Clock frequency is %dkHz\n",
		     adap->name, freqs[clock]);

		pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
	} else {
		int clock;
		int mode;
		int tlow, thi;
		/* Values can be found on PCA9665 datasheet section 7.3.2.6 */
		int min_tlow, min_thi;
		/* These values are the maximum raise and fall values allowed
		 * by the I2C operation mode (Standard, Fast or Fast+)
		 * They are used (added) below to calculate the clock dividers
		 * of PCA9665. Note that they are slightly different of the
		 * real maximum, to allow the change on mode exactly on the
		 * maximum clock rate for each mode
		 */
		int raise_fall_time;

		/* Ignore the reset function from the module,
		 * we can use the parallel bus reset
		 */
		pca_data->reset_chip = pca9665_reset;

		if (pca_data->i2c_clock > 1265800) {
			printk(KERN_WARNING "%s: I2C clock speed too high."
				" Using 1265.8kHz.\n", adap->name);
			pca_data->i2c_clock = 1265800;
		}

		if (pca_data->i2c_clock < 60300) {
			printk(KERN_WARNING "%s: I2C clock speed too low."
				" Using 60.3kHz.\n", adap->name);
			pca_data->i2c_clock = 60300;
		}

		/* To avoid integer overflow, use clock/100 for calculations */
		clock = pca_clock(pca_data) / 100;

		if (pca_data->i2c_clock > 10000) {
			mode = I2C_PCA_MODE_TURBO;
			min_tlow = 14;
			min_thi  = 5;
			raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
		} else if (pca_data->i2c_clock > 4000) {
			mode = I2C_PCA_MODE_FASTP;
			min_tlow = 17;
			min_thi  = 9;
			raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
		} else if (pca_data->i2c_clock > 1000) {
			mode = I2C_PCA_MODE_FAST;
			min_tlow = 44;
			min_thi  = 20;
			raise_fall_time = 58; /* Raise 29e-8s, Fall 29e-8s */
		} else {
			mode = I2C_PCA_MODE_STD;
			min_tlow = 157;
			min_thi  = 134;
			raise_fall_time = 127; /* Raise 29e-8s, Fall 98e-8s */
		}

		/* The minimum clock that respects the thi/tlow = 134/157 is
		 * 64800 Hz. Below that, we have to fix the tlow to 255 and
		 * calculate the thi factor.
		 */
		if (clock < 648) {
			tlow = 255;
			thi = 1000000 - clock * raise_fall_time;
			thi /= (I2C_PCA_OSC_PER * clock) - tlow;
		} else {
			tlow = (1000000 - clock * raise_fall_time) * min_tlow;
			tlow /= I2C_PCA_OSC_PER * clock * (min_thi + min_tlow);
			thi = tlow * min_thi / min_tlow;
		}

		pca_reset(pca_data);

		printk(KERN_INFO
		     "%s: Clock frequency is %dHz\n", adap->name, clock * 100);

		pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IMODE);
		pca_outw(pca_data, I2C_PCA_IND, mode);
		pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
		pca_outw(pca_data, I2C_PCA_IND, tlow);
		pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
		pca_outw(pca_data, I2C_PCA_IND, thi);

		pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
	}
	udelay(500); /* 500 us for oscilator to stabilise */

	return 0;
}