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Commit 7954763b authored by Jarkko Nikula's avatar Jarkko Nikula Committed by Tony Lindgren
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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: default avatarJarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
parent 3a853fb9

Documentation/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -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>

arch/arm/plat-omap/i2c.c

+52 −21
Original line number Diff line number Diff line
@@ -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);

}