linux/arch/arm/plat-omap/i2c.c
Jarkko Nikula 7954763bb9 ARM: OMAP: Add method to register additional I2C busses on the command line, v2
This patch extends command line option "i2c_bus=bus_id,clkrate" so that
it allow to register additional I2C busses that are not registered with
omap_register_i2c_bus from board initialization code.

Purpose of this is to register additional board busses which are routed
to external connectors only without any on board I2C devices.

Cc: linux-i2c@vger.kernel.org
Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2009-03-23 18:51:20 -07:00

240 lines
5.7 KiB
C

/*
* linux/arch/arm/plat-omap/i2c.c
*
* Helper module for board specific I2C bus registration
*
* Copyright (C) 2007 Nokia Corporation.
*
* Contact: Jarkko Nikula <jarkko.nikula@nokia.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <mach/irqs.h>
#include <mach/mux.h>
#define OMAP_I2C_SIZE 0x3f
#define OMAP1_I2C_BASE 0xfffb3800
#define OMAP2_I2C_BASE1 0x48070000
#define OMAP2_I2C_BASE2 0x48072000
#define OMAP2_I2C_BASE3 0x48060000
static const char name[] = "i2c_omap";
#define I2C_RESOURCE_BUILDER(base, irq) \
{ \
.start = (base), \
.end = (base) + OMAP_I2C_SIZE, \
.flags = IORESOURCE_MEM, \
}, \
{ \
.start = (irq), \
.flags = IORESOURCE_IRQ, \
},
static struct resource i2c_resources[][2] = {
{ I2C_RESOURCE_BUILDER(0, 0) },
#if defined(CONFIG_ARCH_OMAP24XX) || defined(CONFIG_ARCH_OMAP34XX)
{ I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE2, INT_24XX_I2C2_IRQ) },
#endif
#if defined(CONFIG_ARCH_OMAP34XX)
{ I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE3, INT_34XX_I2C3_IRQ) },
#endif
};
#define I2C_DEV_BUILDER(bus_id, res, data) \
{ \
.id = (bus_id), \
.name = name, \
.num_resources = ARRAY_SIZE(res), \
.resource = (res), \
.dev = { \
.platform_data = (data), \
}, \
}
static u32 i2c_rate[ARRAY_SIZE(i2c_resources)];
static struct platform_device omap_i2c_devices[] = {
I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_rate[0]),
#if defined(CONFIG_ARCH_OMAP24XX) || defined(CONFIG_ARCH_OMAP34XX)
I2C_DEV_BUILDER(2, i2c_resources[1], &i2c_rate[1]),
#endif
#if defined(CONFIG_ARCH_OMAP34XX)
I2C_DEV_BUILDER(3, i2c_resources[2], &i2c_rate[2]),
#endif
};
#if defined(CONFIG_ARCH_OMAP24XX)
static const int omap24xx_pins[][2] = {
{ M19_24XX_I2C1_SCL, L15_24XX_I2C1_SDA },
{ J15_24XX_I2C2_SCL, H19_24XX_I2C2_SDA },
};
#else
static const int omap24xx_pins[][2] = {};
#endif
#if defined(CONFIG_ARCH_OMAP34XX)
static const int omap34xx_pins[][2] = {
{ K21_34XX_I2C1_SCL, J21_34XX_I2C1_SDA},
{ AF15_34XX_I2C2_SCL, AE15_34XX_I2C2_SDA},
{ AF14_34XX_I2C3_SCL, AG14_34XX_I2C3_SDA},
};
#else
static const int omap34xx_pins[][2] = {};
#endif
#define OMAP_I2C_CMDLINE_SETUP (BIT(31))
static void __init omap_i2c_mux_pins(int bus)
{
int scl, sda;
if (cpu_class_is_omap1()) {
scl = I2C_SCL;
sda = I2C_SDA;
} else if (cpu_is_omap24xx()) {
scl = omap24xx_pins[bus][0];
sda = omap24xx_pins[bus][1];
} else if (cpu_is_omap34xx()) {
scl = omap34xx_pins[bus][0];
sda = omap34xx_pins[bus][1];
} else {
return;
}
omap_cfg_reg(sda);
omap_cfg_reg(scl);
}
static int __init omap_i2c_nr_ports(void)
{
int ports = 0;
if (cpu_class_is_omap1())
ports = 1;
else if (cpu_is_omap24xx())
ports = 2;
else if (cpu_is_omap34xx())
ports = 3;
return ports;
}
static int __init omap_i2c_add_bus(int bus_id)
{
struct platform_device *pdev;
struct resource *res;
resource_size_t base, irq;
pdev = &omap_i2c_devices[bus_id - 1];
if (bus_id == 1) {
res = pdev->resource;
if (cpu_class_is_omap1()) {
base = OMAP1_I2C_BASE;
irq = INT_I2C;
} else {
base = OMAP2_I2C_BASE1;
irq = INT_24XX_I2C1_IRQ;
}
res[0].start = base;
res[0].end = base + OMAP_I2C_SIZE;
res[1].start = irq;
}
omap_i2c_mux_pins(bus_id - 1);
return platform_device_register(pdev);
}
/**
* omap_i2c_bus_setup - Process command line options for the I2C bus speed
* @str: String of options
*
* This function allow to override the default I2C bus speed for given I2C
* bus with a command line option.
*
* Format: i2c_bus=bus_id,clkrate (in kHz)
*
* Returns 1 on success, 0 otherwise.
*/
static int __init omap_i2c_bus_setup(char *str)
{
int ports;
int ints[3];
ports = omap_i2c_nr_ports();
get_options(str, 3, ints);
if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
return 0;
i2c_rate[ints[1] - 1] = ints[2];
i2c_rate[ints[1] - 1] |= OMAP_I2C_CMDLINE_SETUP;
return 1;
}
__setup("i2c_bus=", omap_i2c_bus_setup);
/*
* Register busses defined in command line but that are not registered with
* omap_register_i2c_bus from board initialization code.
*/
static int __init omap_register_i2c_bus_cmdline(void)
{
int i, err = 0;
for (i = 0; i < ARRAY_SIZE(i2c_rate); i++)
if (i2c_rate[i] & OMAP_I2C_CMDLINE_SETUP) {
i2c_rate[i] &= ~OMAP_I2C_CMDLINE_SETUP;
err = omap_i2c_add_bus(i + 1);
if (err)
goto out;
}
out:
return err;
}
subsys_initcall(omap_register_i2c_bus_cmdline);
/**
* omap_register_i2c_bus - register I2C bus with device descriptors
* @bus_id: bus id counting from number 1
* @clkrate: clock rate of the bus in kHz
* @info: pointer into I2C device descriptor table or NULL
* @len: number of descriptors in the table
*
* Returns 0 on success or an error code.
*/
int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
struct i2c_board_info const *info,
unsigned len)
{
int err;
BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
if (info) {
err = i2c_register_board_info(bus_id, info, len);
if (err)
return err;
}
if (!i2c_rate[bus_id - 1])
i2c_rate[bus_id - 1] = clkrate;
i2c_rate[bus_id - 1] &= ~OMAP_I2C_CMDLINE_SETUP;
return omap_i2c_add_bus(bus_id);
}