Commit eff9ec95 authored by Marco Aurelio da Costa's avatar Marco Aurelio da Costa Committed by Jean Delvare
Browse files

i2c-algo-pca: Add PCA9665 support 



Add support for the PCA9665 I2C controller.

Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent bac3e7c2

drivers/i2c/algos/i2c-algo-pca.c

+166 −14
Original line number Diff line number Diff line
@@ -46,6 +46,14 @@ static int i2c_debug; 
#define pca_wait(adap) adap->wait_for_completion(adap->data)

#define pca_reset(adap) adap->reset_chip(adap->data)



static void pca9665_reset(void *pd)

{

	struct i2c_algo_pca_data *adap = pd;

	pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);

	pca_outw(adap, I2C_PCA_IND, 0xA5);

	pca_outw(adap, I2C_PCA_IND, 0x5A);

}



/*

 * Generate a start condition on the i2c bus.

 *
@@ -333,27 +341,171 @@ static const struct i2c_algorithm pca_algo = { 
	.functionality	= pca_func,

};



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;

	}

}



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;

	struct i2c_algo_pca_data *pca_data = adap->algo_data;



		if (pca_data->i2c_clock > 7) {

		printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",

			adap->name);

			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;

			}



	adap->algo = &pca_algo;

		} 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]);

		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;



		struct i2c_algo_pca_data *pca_data = adap->algo_data;



		/* 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;
@@ -388,7 +540,7 @@ EXPORT_SYMBOL(i2c_pca_add_numbered_bus); 


MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "

	"Wolfram Sang <w.sang@pengutronix.de>");

MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");

MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");

MODULE_LICENSE("GPL");



module_param(i2c_debug, int, 0);

drivers/i2c/busses/Kconfig

+4 −4
Original line number Diff line number Diff line
@@ -617,12 +617,12 @@ config I2C_ELEKTOR 
	  will be called i2c-elektor.



config I2C_PCA_ISA

	tristate "PCA9564 on an ISA bus"

	tristate "PCA9564/PCA9665 on an ISA bus"

	depends on ISA

	select I2C_ALGOPCA

	default n

	help

	  This driver supports ISA boards using the Philips PCA9564

	  This driver supports ISA boards using the Philips PCA9564/PCA9665

	  parallel bus to I2C bus controller.



	  This driver can also be built as a module.  If so, the module
@@ -634,11 +634,11 @@ config I2C_PCA_ISA 
	  time).  If unsure, say N.



config I2C_PCA_PLATFORM

	tristate "PCA9564 as platform device"

	tristate "PCA9564/PCA9665 as platform device"

	select I2C_ALGOPCA

	default n

	help

	  This driver supports a memory mapped Philips PCA9564

	  This driver supports a memory mapped Philips PCA9564/PCA9665

	  parallel bus to I2C bus controller.



	  This driver can also be built as a module.  If so, the module

drivers/i2c/busses/i2c-pca-isa.c

+10 −4
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ static int irq = -1; 


/* Data sheet recommends 59kHz for 100kHz operation due to variation

 * in the actual clock rate */

static int clock  = I2C_PCA_CON_59kHz;

static int clock  = 59000;



static wait_queue_head_t pca_wait;
@@ -103,7 +103,7 @@ static struct i2c_algo_pca_data pca_isa_data = { 
static struct i2c_adapter pca_isa_ops = {

	.owner          = THIS_MODULE,

	.algo_data	= &pca_isa_data,

	.name		= "PCA9564 ISA Adapter",

	.name		= "PCA9564/PCA9665 ISA Adapter",

	.timeout	= 100,

};
@@ -196,7 +196,7 @@ static void __exit pca_isa_exit(void) 
}



MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");

MODULE_DESCRIPTION("ISA base PCA9564 driver");

MODULE_DESCRIPTION("ISA base PCA9564/PCA9665 driver");

MODULE_LICENSE("GPL");



module_param(base, ulong, 0);
@@ -205,7 +205,13 @@ MODULE_PARM_DESC(base, "I/O base address"); 
module_param(irq, int, 0);

MODULE_PARM_DESC(irq, "IRQ");

module_param(clock, int, 0);

MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet");

MODULE_PARM_DESC(clock, "Clock rate in hertz.\n\t\t"

		"For PCA9564: 330000,288000,217000,146000,"

		"88000,59000,44000,36000\n"

		"\t\tFor PCA9665:\tStandard: 60300 - 100099\n"

		"\t\t\t\tFast: 100100 - 400099\n"

		"\t\t\t\tFast+: 400100 - 10000099\n"

		"\t\t\t\tTurbo: Up to 1265800");



module_init(pca_isa_init);

module_exit(pca_isa_exit);

drivers/i2c/busses/i2c-pca-platform.c

+5 −4
Original line number Diff line number Diff line
@@ -172,7 +172,8 @@ static int __devinit i2c_pca_pf_probe(struct platform_device *pdev) 


	i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0;

	i2c->adap.owner = THIS_MODULE;

	snprintf(i2c->adap.name, sizeof(i2c->adap.name), "PCA9564 at 0x%08lx",

	snprintf(i2c->adap.name, sizeof(i2c->adap.name),

		 "PCA9564/PCA9665 at 0x%08lx",

		 (unsigned long) res->start);

	i2c->adap.algo_data = &i2c->algo_data;

	i2c->adap.dev.parent = &pdev->dev;
@@ -246,7 +247,7 @@ static int __devinit i2c_pca_pf_probe(struct platform_device *pdev) 
e_alloc:

	release_mem_region(res->start, res_len(res));

e_print:

	printk(KERN_ERR "Registering PCA9564 FAILED! (%d)\n", ret);

	printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret);

	return ret;

}
@@ -290,7 +291,7 @@ static void __exit i2c_pca_pf_exit(void) 
}



MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");

MODULE_DESCRIPTION("I2C-PCA9564 platform driver");

MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");

MODULE_LICENSE("GPL");



module_init(i2c_pca_pf_init);

include/linux/i2c-algo-pca.h

+31 −2
Original line number Diff line number Diff line 
#ifndef _LINUX_I2C_ALGO_PCA_H

#define _LINUX_I2C_ALGO_PCA_H



/* Clock speeds for the bus */

/* Chips known to the pca algo */

#define I2C_PCA_CHIP_9564	0x00

#define I2C_PCA_CHIP_9665	0x01



/* Internal period for PCA9665 oscilator */

#define I2C_PCA_OSC_PER		3 /* e10-8s */



/* Clock speeds for the bus for PCA9564*/

#define I2C_PCA_CON_330kHz	0x00

#define I2C_PCA_CON_288kHz	0x01

#define I2C_PCA_CON_217kHz	0x02
@@ -18,6 +25,26 @@ 
#define I2C_PCA_ADR		0x02 /* OWN ADR Read/Write */

#define I2C_PCA_CON		0x03 /* CONTROL Read/Write */



/* PCA9665 registers */

#define I2C_PCA_INDPTR          0x00 /* INDIRECT Pointer Write Only */

#define I2C_PCA_IND             0x02 /* INDIRECT Read/Write */



/* PCA9665 indirect registers */

#define I2C_PCA_ICOUNT          0x00 /* Byte Count for buffered mode */

#define I2C_PCA_IADR            0x01 /* OWN ADR */

#define I2C_PCA_ISCLL           0x02 /* SCL LOW period */

#define I2C_PCA_ISCLH           0x03 /* SCL HIGH period */

#define I2C_PCA_ITO             0x04 /* TIMEOUT */

#define I2C_PCA_IPRESET         0x05 /* Parallel bus reset */

#define I2C_PCA_IMODE           0x06 /* I2C Bus mode */



/* PCA9665 I2C bus mode */

#define I2C_PCA_MODE_STD        0x00 /* Standard mode */

#define I2C_PCA_MODE_FAST       0x01 /* Fast mode */

#define I2C_PCA_MODE_FASTP      0x02 /* Fast Plus mode */

#define I2C_PCA_MODE_TURBO      0x03 /* Turbo mode */





#define I2C_PCA_CON_AA		0x80 /* Assert Acknowledge */

#define I2C_PCA_CON_ENSIO	0x40 /* Enable */

#define I2C_PCA_CON_STA		0x20 /* Start */
@@ -31,7 +58,9 @@ struct i2c_algo_pca_data { 
	int  (*read_byte)		(void *data, int reg);

	int  (*wait_for_completion)	(void *data);

	void (*reset_chip)		(void *data);

	/* i2c_clock values are defined in linux/i2c-algo-pca.h */

	/* For PCA9564, use one of the predefined frequencies:

	 * 330000, 288000, 217000, 146000, 88000, 59000, 44000, 36000

	 * For PCA9665, use the frequency you want here. */

	unsigned int			i2c_clock;

};