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authorDaniel Silverstone <dsilvers@simtec.co.uk>2009-03-13 13:53:46 +0000
committerBen Dooks <ben-linux@fluff.org>2009-04-07 10:18:33 +0100
commitc564e6ae6c5aa6e3995ff87ed4a32b4788ad5109 (patch)
treeb773106104d9897d945709d3bff8a56ff6586da8 /arch/arm/plat-s3c/include
parenta192f7153bb33151f83440cd9c0442233a064bf1 (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.h33
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);
};