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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2007-03-04 20:40:50 +0000 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2007-03-04 20:40:50 +0000 |
commit | 8d91cbad8e6fd5b37bf584740f134508709ba035 (patch) | |
tree | 1ce49dd94842d413597f4fb4e387584ce481d8a6 /drivers/i2c/busses/i2c-acorn.c | |
parent | 23d046f43a05155e050a68f3ad1f19b672713374 (diff) | |
download | linux-8d91cbad8e6fd5b37bf584740f134508709ba035.tar.bz2 |
[ARM] Acorn: move the i2c bus driver into drivers/i2c
Move the Acorn IOC/IOMD I2C bus driver from drivers/i2c, strip
out the reminants of the platform specific parts of the old
PCF8583 RTC code, and remove the old obsolete PCF8583 driver.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/i2c/busses/i2c-acorn.c')
-rw-r--r-- | drivers/i2c/busses/i2c-acorn.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-acorn.c b/drivers/i2c/busses/i2c-acorn.c new file mode 100644 index 000000000000..09bd7f40b90c --- /dev/null +++ b/drivers/i2c/busses/i2c-acorn.c @@ -0,0 +1,97 @@ +/* + * linux/drivers/acorn/char/i2c.c + * + * Copyright (C) 2000 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * ARM IOC/IOMD i2c driver. + * + * On Acorn machines, the following i2c devices are on the bus: + * - PCF8583 real time clock & static RAM + */ +#include <linux/init.h> +#include <linux/i2c.h> +#include <linux/i2c-algo-bit.h> + +#include <asm/hardware.h> +#include <asm/io.h> +#include <asm/hardware/ioc.h> +#include <asm/system.h> + +#define FORCE_ONES 0xdc +#define SCL 0x02 +#define SDA 0x01 + +/* + * We must preserve all non-i2c output bits in IOC_CONTROL. + * Note also that we need to preserve the value of SCL and + * SDA outputs as well (which may be different from the + * values read back from IOC_CONTROL). + */ +static u_int force_ones; + +static void ioc_setscl(void *data, int state) +{ + u_int ioc_control = ioc_readb(IOC_CONTROL) & ~(SCL | SDA); + u_int ones = force_ones; + + if (state) + ones |= SCL; + else + ones &= ~SCL; + + force_ones = ones; + + ioc_writeb(ioc_control | ones, IOC_CONTROL); +} + +static void ioc_setsda(void *data, int state) +{ + u_int ioc_control = ioc_readb(IOC_CONTROL) & ~(SCL | SDA); + u_int ones = force_ones; + + if (state) + ones |= SDA; + else + ones &= ~SDA; + + force_ones = ones; + + ioc_writeb(ioc_control | ones, IOC_CONTROL); +} + +static int ioc_getscl(void *data) +{ + return (ioc_readb(IOC_CONTROL) & SCL) != 0; +} + +static int ioc_getsda(void *data) +{ + return (ioc_readb(IOC_CONTROL) & SDA) != 0; +} + +static struct i2c_algo_bit_data ioc_data = { + .setsda = ioc_setsda, + .setscl = ioc_setscl, + .getsda = ioc_getsda, + .getscl = ioc_getscl, + .udelay = 80, + .timeout = 100 +}; + +static struct i2c_adapter ioc_ops = { + .id = I2C_HW_B_IOC, + .algo_data = &ioc_data, +}; + +static int __init i2c_ioc_init(void) +{ + force_ones = FORCE_ONES | SCL | SDA; + + return i2c_bit_add_bus(&ioc_ops); +} + +__initcall(i2c_ioc_init); |