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authorJarkko Nikula <jarkko.nikula@nokia.com>2009-03-23 18:07:48 -0700
committerTony Lindgren <tony@atomide.com>2009-03-23 18:51:20 -0700
commit7954763bb95fd484a76d1151b40956fe331d23b9 (patch)
tree78843cb78aa8706cb3f5110666f052e32b5fce41
parent3a853fb933ddf9c5ea8c9f7c665dd8def26bceae (diff)
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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>
-rw-r--r--Documentation/kernel-parameters.txt2
-rw-r--r--arch/arm/plat-omap/i2c.c73
2 files changed, 54 insertions, 21 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d775076d156..ef9827f7c84 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -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>
diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
index aa70e435fa7..a303071d5e3 100644
--- a/arch/arm/plat-omap/i2c.c
+++ b/arch/arm/plat-omap/i2c.c
@@ -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);
}