i2c-algo-pca: Extend for future drivers
The separation between algorithm and adapter was unsharp at places. This was partly hidden by the fact, that the ISA-driver allowed just one instance and had all private data in static variables. This patch makes neccessary preparations to add a platform driver on top of the algorithm, while still supporting ISA. Note: Due to lack of hardware, the ISA-driver could not be tested except that it builds. Concerning the core struct i2c_algo_pca_data: - A private data field was added, all hardware dependant data may go here. Similar to other algorithms, now a pointer to this data is passed to the adapter's functions. In order to make as less changes as possible to the ISA-driver, it leaves the private data empty and still only uses its static variables. - A "reset_chip" function pointer was added; such a functionality must come from the adapter, not the algorithm. - use a variable "i2c_clock" instead of a function pointer "get_clock", allowing for write access to a default in case a wrong value was supplied. In the algorithm-file: - move "i2c-pca-algo.h" into "linux/i2c-algo-pca.h" - now using per_instance timeout values (i2c_adap->timeout) - error messages specify the device, not only the driver name - restructure initialization to easily support "i2c_add_numbered_adapter" - drop "retries" and "own" (i2c address) as they were unused (The state-machine for I2C-communication was not touched.) In the ISA-driver: - adapt to new algorithm Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Wolfram Sang
Jean Delvare
Родитель
3d4382913f
Коммит
c01b083105
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@ -1,6 +1,7 @@
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/*
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* i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
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* Copyright (C) 2004 Arcom Control Systems
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* Copyright (C) 2008 Pengutronix
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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@ -21,14 +22,10 @@
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-pca.h>
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#include "i2c-algo-pca.h"
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#define DRIVER "i2c-algo-pca"
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#define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
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#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
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@ -36,15 +33,15 @@
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static int i2c_debug;
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#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)
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#define pca_inw(adap, reg) adap->read_byte(adap, reg)
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#define pca_outw(adap, reg, val) adap->write_byte(adap->data, reg, val)
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#define pca_inw(adap, reg) adap->read_byte(adap->data, reg)
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#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
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#define pca_clock(adap) adap->get_clock(adap)
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#define pca_own(adap) adap->get_own(adap)
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#define pca_clock(adap) adap->i2c_clock
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#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
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#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
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#define pca_wait(adap) adap->wait_for_interrupt(adap)
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#define pca_wait(adap) adap->wait_for_completion(adap->data)
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#define pca_reset(adap) adap->reset_chip(adap->data)
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/*
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* Generate a start condition on the i2c bus.
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@ -168,15 +165,6 @@ static void pca_rx_ack(struct i2c_algo_pca_data *adap,
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pca_wait(adap);
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}
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/*
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* Reset the i2c bus / SIO
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*/
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static void pca_reset(struct i2c_algo_pca_data *adap)
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{
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/* apparently only an external reset will do it. not a lot can be done */
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printk(KERN_ERR DRIVER ": Haven't figured out how to do a reset yet\n");
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}
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static int pca_xfer(struct i2c_adapter *i2c_adap,
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struct i2c_msg *msgs,
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int num)
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@ -187,7 +175,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
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int numbytes = 0;
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int state;
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int ret;
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int timeout = 100;
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int timeout = i2c_adap->timeout;
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while ((state = pca_status(adap)) != 0xf8 && timeout--) {
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msleep(10);
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@ -317,7 +305,7 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
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pca_reset(adap);
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goto out;
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default:
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printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
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dev_err(&i2c_adap->dev, "unhandled SIO state 0x%02x\n", state);
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break;
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}
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@ -337,53 +325,65 @@ static u32 pca_func(struct i2c_adapter *adap)
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
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}
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static int pca_init(struct i2c_algo_pca_data *adap)
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{
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static int freqs[] = {330,288,217,146,88,59,44,36};
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int own, clock;
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own = pca_own(adap);
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clock = pca_clock(adap);
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DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
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DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);
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pca_outw(adap, I2C_PCA_ADR, own << 1);
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pca_set_con(adap, I2C_PCA_CON_ENSIO | clock);
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udelay(500); /* 500 us for oscilator to stabilise */
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return 0;
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}
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static const struct i2c_algorithm pca_algo = {
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.master_xfer = pca_xfer,
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.functionality = pca_func,
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};
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static int pca_init(struct i2c_adapter *adap)
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{
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static int freqs[] = {330,288,217,146,88,59,44,36};
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int clock;
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struct i2c_algo_pca_data *pca_data = adap->algo_data;
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if (pca_data->i2c_clock > 7) {
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printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",
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adap->name);
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pca_data->i2c_clock = I2C_PCA_CON_59kHz;
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}
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adap->algo = &pca_algo;
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pca_reset(pca_data);
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clock = pca_clock(pca_data);
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DEB1(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name, freqs[clock]);
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pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
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udelay(500); /* 500 us for oscilator to stabilise */
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return 0;
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}
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/*
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* registering functions to load algorithms at runtime
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*/
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int i2c_pca_add_bus(struct i2c_adapter *adap)
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{
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struct i2c_algo_pca_data *pca_adap = adap->algo_data;
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int rval;
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/* register new adapter to i2c module... */
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adap->algo = &pca_algo;
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adap->timeout = 100; /* default values, should */
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adap->retries = 3; /* be replaced by defines */
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if ((rval = pca_init(pca_adap)))
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rval = pca_init(adap);
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if (rval)
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return rval;
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rval = i2c_add_adapter(adap);
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return rval;
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return i2c_add_adapter(adap);
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}
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EXPORT_SYMBOL(i2c_pca_add_bus);
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MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
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int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
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{
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int rval;
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rval = pca_init(adap);
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if (rval)
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return rval;
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return i2c_add_numbered_adapter(adap);
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}
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EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
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MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
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"Wolfram Sang <w.sang@pengutronix.de>");
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MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
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MODULE_LICENSE("GPL");
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@ -1,26 +0,0 @@
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#ifndef I2C_PCA9564_H
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#define I2C_PCA9564_H 1
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#define I2C_PCA_STA 0x00 /* STATUS Read Only */
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#define I2C_PCA_TO 0x00 /* TIMEOUT Write Only */
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#define I2C_PCA_DAT 0x01 /* DATA Read/Write */
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#define I2C_PCA_ADR 0x02 /* OWN ADR Read/Write */
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#define I2C_PCA_CON 0x03 /* CONTROL Read/Write */
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#define I2C_PCA_CON_AA 0x80 /* Assert Acknowledge */
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#define I2C_PCA_CON_ENSIO 0x40 /* Enable */
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#define I2C_PCA_CON_STA 0x20 /* Start */
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#define I2C_PCA_CON_STO 0x10 /* Stop */
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#define I2C_PCA_CON_SI 0x08 /* Serial Interrupt */
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#define I2C_PCA_CON_CR 0x07 /* Clock Rate (MASK) */
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#define I2C_PCA_CON_330kHz 0x00
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#define I2C_PCA_CON_288kHz 0x01
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#define I2C_PCA_CON_217kHz 0x02
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#define I2C_PCA_CON_146kHz 0x03
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#define I2C_PCA_CON_88kHz 0x04
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#define I2C_PCA_CON_59kHz 0x05
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#define I2C_PCA_CON_44kHz 0x06
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#define I2C_PCA_CON_36kHz 0x07
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#endif /* I2C_PCA9564_H */
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@ -1,6 +1,7 @@
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/*
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* i2c-pca-isa.c driver for PCA9564 on ISA boards
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* Copyright (C) 2004 Arcom Control Systems
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* Copyright (C) 2008 Pengutronix
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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@ -22,11 +23,9 @@
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/wait.h>
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#include <linux/isa.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-pca.h>
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@ -34,13 +33,9 @@
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#include <asm/io.h>
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#include <asm/irq.h>
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#include "../algos/i2c-algo-pca.h"
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#define DRIVER "i2c-pca-isa"
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#define IO_SIZE 4
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#undef DEBUG_IO
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//#define DEBUG_IO
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static unsigned long base = 0x330;
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static int irq = 10;
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@ -48,22 +43,9 @@ static int irq = 10;
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* in the actual clock rate */
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static int clock = I2C_PCA_CON_59kHz;
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static int own = 0x55;
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static wait_queue_head_t pca_wait;
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static int pca_isa_getown(struct i2c_algo_pca_data *adap)
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{
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return (own);
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}
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static int pca_isa_getclock(struct i2c_algo_pca_data *adap)
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{
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return (clock);
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}
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static void
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pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val)
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static void pca_isa_writebyte(void *pd, int reg, int val)
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{
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#ifdef DEBUG_IO
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static char *names[] = { "T/O", "DAT", "ADR", "CON" };
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@ -72,8 +54,7 @@ pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val)
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outb(val, base+reg);
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}
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static int
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pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg)
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static int pca_isa_readbyte(void *pd, int reg)
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{
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int res = inb(base+reg);
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#ifdef DEBUG_IO
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@ -85,31 +66,37 @@ pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg)
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return res;
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}
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static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap)
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static int pca_isa_waitforcompletion(void *pd)
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{
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int ret = 0;
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if (irq > -1) {
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ret = wait_event_interruptible(pca_wait,
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pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI);
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pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI);
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} else {
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while ((pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
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while ((pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
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udelay(100);
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}
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return ret;
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}
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static void pca_isa_resetchip(void *pd)
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{
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/* apparently only an external reset will do it. not a lot can be done */
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printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n");
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}
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static irqreturn_t pca_handler(int this_irq, void *dev_id) {
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wake_up_interruptible(&pca_wait);
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return IRQ_HANDLED;
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}
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static struct i2c_algo_pca_data pca_isa_data = {
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.get_own = pca_isa_getown,
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.get_clock = pca_isa_getclock,
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/* .data intentionally left NULL, not needed with ISA */
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.write_byte = pca_isa_writebyte,
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.read_byte = pca_isa_readbyte,
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.wait_for_interrupt = pca_isa_waitforinterrupt,
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.wait_for_completion = pca_isa_waitforcompletion,
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.reset_chip = pca_isa_resetchip,
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};
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static struct i2c_adapter pca_isa_ops = {
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@ -117,6 +104,7 @@ static struct i2c_adapter pca_isa_ops = {
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.id = I2C_HW_A_ISA,
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.algo_data = &pca_isa_data,
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.name = "PCA9564 ISA Adapter",
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.timeout = 100,
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};
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static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
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@ -144,6 +132,7 @@ static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
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}
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}
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pca_isa_data.i2c_clock = clock;
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if (i2c_pca_add_bus(&pca_isa_ops) < 0) {
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dev_err(dev, "Failed to add i2c bus\n");
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goto out_irq;
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@ -178,7 +167,7 @@ static struct isa_driver pca_isa_driver = {
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.remove = __devexit_p(pca_isa_remove),
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.driver = {
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.owner = THIS_MODULE,
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.name = "i2c-pca-isa",
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.name = DRIVER,
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}
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};
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@ -204,7 +193,5 @@ MODULE_PARM_DESC(irq, "IRQ");
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module_param(clock, int, 0);
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MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet");
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module_param(own, int, 0); /* the driver can't do slave mode, so there's no real point in this */
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module_init(pca_isa_init);
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module_exit(pca_isa_exit);
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@ -1,14 +1,41 @@
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#ifndef _LINUX_I2C_ALGO_PCA_H
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#define _LINUX_I2C_ALGO_PCA_H
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/* Clock speeds for the bus */
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#define I2C_PCA_CON_330kHz 0x00
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#define I2C_PCA_CON_288kHz 0x01
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#define I2C_PCA_CON_217kHz 0x02
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#define I2C_PCA_CON_146kHz 0x03
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#define I2C_PCA_CON_88kHz 0x04
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#define I2C_PCA_CON_59kHz 0x05
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#define I2C_PCA_CON_44kHz 0x06
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#define I2C_PCA_CON_36kHz 0x07
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/* PCA9564 registers */
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#define I2C_PCA_STA 0x00 /* STATUS Read Only */
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#define I2C_PCA_TO 0x00 /* TIMEOUT Write Only */
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#define I2C_PCA_DAT 0x01 /* DATA Read/Write */
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#define I2C_PCA_ADR 0x02 /* OWN ADR Read/Write */
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#define I2C_PCA_CON 0x03 /* CONTROL Read/Write */
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#define I2C_PCA_CON_AA 0x80 /* Assert Acknowledge */
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#define I2C_PCA_CON_ENSIO 0x40 /* Enable */
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#define I2C_PCA_CON_STA 0x20 /* Start */
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#define I2C_PCA_CON_STO 0x10 /* Stop */
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#define I2C_PCA_CON_SI 0x08 /* Serial Interrupt */
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#define I2C_PCA_CON_CR 0x07 /* Clock Rate (MASK) */
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struct i2c_algo_pca_data {
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int (*get_own) (struct i2c_algo_pca_data *adap); /* Obtain own address */
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int (*get_clock) (struct i2c_algo_pca_data *adap);
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void (*write_byte) (struct i2c_algo_pca_data *adap, int reg, int val);
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int (*read_byte) (struct i2c_algo_pca_data *adap, int reg);
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int (*wait_for_interrupt) (struct i2c_algo_pca_data *adap);
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void *data; /* private low level data */
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void (*write_byte) (void *data, int reg, int val);
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int (*read_byte) (void *data, int reg);
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int (*wait_for_completion) (void *data);
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void (*reset_chip) (void *data);
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/* i2c_clock values are defined in linux/i2c-algo-pca.h */
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unsigned int i2c_clock;
|
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};
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int i2c_pca_add_bus(struct i2c_adapter *);
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int i2c_pca_add_numbered_bus(struct i2c_adapter *);
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#endif /* _LINUX_I2C_ALGO_PCA_H */
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