diff options
| author | Daniel Silverstone <dsilvers@simtec.co.uk> | 2009-03-13 13:53:46 +0000 |
|---|---|---|
| committer | Ben Dooks <ben-linux@fluff.org> | 2009-04-07 10:18:33 +0100 |
| commit | c564e6ae6c5aa6e3995ff87ed4a32b4788ad5109 (patch) | |
| tree | b773106104d9897d945709d3bff8a56ff6586da8 /arch/arm/plat-s3c/include | |
| parent | a192f7153bb33151f83440cd9c0442233a064bf1 (diff) | |
i2c-s3c2410: Simplify bus frequency calculation
The platform data for the i2c-s3c2410 driver used to allow a min,
max and desired frequency for the I2C bus. This patch reduces it
to simply a desired frequency ceiling and corrects all the uses
of the platform data appropriately.
This means, for example, that on a system with a 66MHz fclk, a
request for 100KHz will achieve 65KHz which is safe and
acceptable, rather than 378KHz which it would have achieved
without this change.
Signed-off-by: Simtec Linux Team <linux@simtec.co.uk>
Signed-off-by: Daniel Silverstone <dsilvers@simtec.co.uk>
[ben-linux@fluff.org: tidy subject and description]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'arch/arm/plat-s3c/include')
| -rw-r--r-- | arch/arm/plat-s3c/include/plat/iic.h | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/arch/arm/plat-s3c/include/plat/iic.h b/arch/arm/plat-s3c/include/plat/iic.h index dc1dfcb9bc6..67450f11574 100644 --- a/arch/arm/plat-s3c/include/plat/iic.h +++ b/arch/arm/plat-s3c/include/plat/iic.h @@ -1,9 +1,9 @@ -/* arch/arm/mach-s3c2410/include/mach/iic.h +/* arch/arm/plat-s3c/include/plat/iic.h * - * Copyright (c) 2004 Simtec Electronics + * Copyright 2004,2009 Simtec Electronics * Ben Dooks <ben@simtec.co.uk> * - * S3C2410 - I2C Controller platfrom_device info + * S3C - I2C Controller platform_device info * * 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 @@ -15,19 +15,24 @@ #define S3C_IICFLG_FILTER (1<<0) /* enable s3c2440 filter */ -/* Notes: - * 1) All frequencies are expressed in Hz - * 2) A value of zero is `do not care` -*/ - +/** + * struct s3c2410_platform_i2c - Platform data for s3c I2C. + * @bus_num: The bus number to use (if possible). + * @flags: Any flags for the I2C bus (E.g. S3C_IICFLK_FILTER). + * @slave_addr: The I2C address for the slave device (if enabled). + * @frequency: The desired frequency in Hz of the bus. This is + * guaranteed to not be exceeded. If the caller does + * not care, use zero and the driver will select a + * useful default. + * @sda_delay: The delay (in ns) applied to SDA edges. + * @cfg_gpio: A callback to configure the pins for I2C operation. + */ struct s3c2410_platform_i2c { - int bus_num; /* bus number to use */ + int bus_num; unsigned int flags; - unsigned int slave_addr; /* slave address for controller */ - unsigned long bus_freq; /* standard bus frequency */ - unsigned long max_freq; /* max frequency for the bus */ - unsigned long min_freq; /* min frequency for the bus */ - unsigned int sda_delay; /* pclks (s3c2440 only) */ + unsigned int slave_addr; + unsigned long frequency; + unsigned int sda_delay; void (*cfg_gpio)(struct platform_device *dev); }; |