diff options
author | Wolfram Sang <w.sang@pengutronix.de> | 2008-04-22 20:16:46 (GMT) |
---|---|---|
committer | Jean Delvare <khali@hyperion.delvare> | 2008-04-22 20:16:46 (GMT) |
commit | c01b0831057381c7f6e0bfb3634bac8c5f7fb256 (patch) | |
tree | 43fb4c2d626df0c32f3196c81062592ab60ccd12 /drivers/i2c/busses/i2c-pca-isa.c | |
parent | 3d4382913f9a86f0d9ff47740feb427415fe7234 (diff) | |
download | linux-c01b0831057381c7f6e0bfb3634bac8c5f7fb256.tar.xz |
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>
Diffstat (limited to 'drivers/i2c/busses/i2c-pca-isa.c')
-rw-r--r-- | drivers/i2c/busses/i2c-pca-isa.c | 51 |
1 files changed, 19 insertions, 32 deletions
diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c index 93ed325..a119784 100644 --- a/drivers/i2c/busses/i2c-pca-isa.c +++ b/drivers/i2c/busses/i2c-pca-isa.c @@ -1,6 +1,7 @@ /* * i2c-pca-isa.c driver for PCA9564 on ISA boards * Copyright (C) 2004 Arcom Control Systems + * Copyright (C) 2008 Pengutronix * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -22,11 +23,9 @@ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/delay.h> -#include <linux/slab.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/wait.h> - #include <linux/isa.h> #include <linux/i2c.h> #include <linux/i2c-algo-pca.h> @@ -34,13 +33,9 @@ #include <asm/io.h> #include <asm/irq.h> -#include "../algos/i2c-algo-pca.h" - +#define DRIVER "i2c-pca-isa" #define IO_SIZE 4 -#undef DEBUG_IO -//#define DEBUG_IO - static unsigned long base = 0x330; static int irq = 10; @@ -48,22 +43,9 @@ static int irq = 10; * in the actual clock rate */ static int clock = I2C_PCA_CON_59kHz; -static int own = 0x55; - static wait_queue_head_t pca_wait; -static int pca_isa_getown(struct i2c_algo_pca_data *adap) -{ - return (own); -} - -static int pca_isa_getclock(struct i2c_algo_pca_data *adap) -{ - return (clock); -} - -static void -pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val) +static void pca_isa_writebyte(void *pd, int reg, int val) { #ifdef DEBUG_IO static char *names[] = { "T/O", "DAT", "ADR", "CON" }; @@ -72,8 +54,7 @@ pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val) outb(val, base+reg); } -static int -pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg) +static int pca_isa_readbyte(void *pd, int reg) { int res = inb(base+reg); #ifdef DEBUG_IO @@ -85,31 +66,37 @@ pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg) return res; } -static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap) +static int pca_isa_waitforcompletion(void *pd) { int ret = 0; if (irq > -1) { ret = wait_event_interruptible(pca_wait, - pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI); + pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI); } else { - while ((pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) + while ((pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) udelay(100); } return ret; } +static void pca_isa_resetchip(void *pd) +{ + /* apparently only an external reset will do it. not a lot can be done */ + printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n"); +} + static irqreturn_t pca_handler(int this_irq, void *dev_id) { wake_up_interruptible(&pca_wait); return IRQ_HANDLED; } static struct i2c_algo_pca_data pca_isa_data = { - .get_own = pca_isa_getown, - .get_clock = pca_isa_getclock, + /* .data intentionally left NULL, not needed with ISA */ .write_byte = pca_isa_writebyte, .read_byte = pca_isa_readbyte, - .wait_for_interrupt = pca_isa_waitforinterrupt, + .wait_for_completion = pca_isa_waitforcompletion, + .reset_chip = pca_isa_resetchip, }; static struct i2c_adapter pca_isa_ops = { @@ -117,6 +104,7 @@ static struct i2c_adapter pca_isa_ops = { .id = I2C_HW_A_ISA, .algo_data = &pca_isa_data, .name = "PCA9564 ISA Adapter", + .timeout = 100, }; static int __devinit pca_isa_probe(struct device *dev, unsigned int id) @@ -144,6 +132,7 @@ static int __devinit pca_isa_probe(struct device *dev, unsigned int id) } } + pca_isa_data.i2c_clock = clock; if (i2c_pca_add_bus(&pca_isa_ops) < 0) { dev_err(dev, "Failed to add i2c bus\n"); goto out_irq; @@ -178,7 +167,7 @@ static struct isa_driver pca_isa_driver = { .remove = __devexit_p(pca_isa_remove), .driver = { .owner = THIS_MODULE, - .name = "i2c-pca-isa", + .name = DRIVER, } }; @@ -204,7 +193,5 @@ 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_param(own, int, 0); /* the driver can't do slave mode, so there's no real point in this */ - module_init(pca_isa_init); module_exit(pca_isa_exit); |