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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>
This commit is contained in:
Jarkko Nikula 2009-03-23 18:07:48 -07:00 committed by Tony Lindgren
parent 3a853fb933
commit 7954763bb9
2 changed files with 54 additions and 21 deletions
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2
Documentation/kernel-parameters.txt
View File

@ -831,6 +831,8 @@ and is between 256 and 4096 characters. It is defined in the file
terminal devices. Valid values: 0..8
i2c_bus= [HW] Override the default board specific I2C bus speed
or register an additional I2C bus that is not
registered from board initialization code.
Format:
<bus_id>,<clkrate>

73
arch/arm/plat-omap/i2c.c
View File

@ -98,6 +98,8 @@ static const int omap34xx_pins[][2] = {
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;
@ -133,6 +135,31 @@ static int __init omap_i2c_nr_ports(void)
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
@ -154,11 +181,33 @@ static int __init omap_i2c_bus_setup(char *str)
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
@ -173,9 +222,6 @@ int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
unsigned len)
{
int err;
struct platform_device *pdev;
struct resource *res;
resource_size_t base, irq;
BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
@ -185,24 +231,9 @@ int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
return err;
}
pdev = &omap_i2c_devices[bus_id - 1];
if (i2c_rate[bus_id - 1] == 0)
if (!i2c_rate[bus_id - 1])
i2c_rate[bus_id - 1] = clkrate;
i2c_rate[bus_id - 1] &= ~OMAP_I2C_CMDLINE_SETUP;
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);
return omap_i2c_add_bus(bus_id);
}