linux/arch/arm/plat-s3c/dev-i2c1.c
Daniel Silverstone c564e6ae6c 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>
2009-04-07 10:18:33 +01:00

69 lines
1.5 KiB
C

/* linux/arch/arm/plat-s3c/dev-i2c1.c
*
* Copyright 2008,2009 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* S3C series device definition for i2c device 1
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/platform_device.h>
#include <mach/irqs.h>
#include <mach/map.h>
#include <plat/regs-iic.h>
#include <plat/iic.h>
#include <plat/devs.h>
#include <plat/cpu.h>
static struct resource s3c_i2c_resource[] = {
[0] = {
.start = S3C_PA_IIC1,
.end = S3C_PA_IIC1 + SZ_4K - 1,
.flags = IORESOURCE_MEM,
},
[1] = {
.start = IRQ_IIC1,
.end = IRQ_IIC1,
.flags = IORESOURCE_IRQ,
},
};
struct platform_device s3c_device_i2c1 = {
.name = "s3c2410-i2c",
.id = 1,
.num_resources = ARRAY_SIZE(s3c_i2c_resource),
.resource = s3c_i2c_resource,
};
static struct s3c2410_platform_i2c default_i2c_data1 __initdata = {
.flags = 0,
.bus_num = 1,
.slave_addr = 0x10,
.frequency = 100*1000,
.sda_delay = 100,
};
void __init s3c_i2c1_set_platdata(struct s3c2410_platform_i2c *pd)
{
struct s3c2410_platform_i2c *npd;
if (!pd)
pd = &default_i2c_data1;
npd = kmemdup(pd, sizeof(struct s3c2410_platform_i2c), GFP_KERNEL);
if (!npd)
printk(KERN_ERR "%s: no memory for platform data\n", __func__);
else if (!npd->cfg_gpio)
npd->cfg_gpio = s3c_i2c1_cfg_gpio;
s3c_device_i2c1.dev.platform_data = npd;
}