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There is sometimes a need for the ocores driver to add devices to the bus when installed. i2c_register_board_info can not always be used, because the I2C devices are not known at an early state, they could for instance be connected on a I2C bus on a PCI device which has the Open Cores IP. i2c_new_device can not be used in all cases either since the resulting bus nummer might be unknown. The solution is the pass a list of I2C devices in the platform data to the Open Cores driver. This is useful for MFD drivers. Signed-off-by: Richard Röjfors <richard.rojfors.ext@mocean-labs.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
69 lines
1.8 KiB
Plaintext
69 lines
1.8 KiB
Plaintext
Kernel driver i2c-ocores
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Supported adapters:
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* OpenCores.org I2C controller by Richard Herveille (see datasheet link)
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Datasheet: http://www.opencores.org/projects.cgi/web/i2c/overview
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Author: Peter Korsgaard <jacmet@sunsite.dk>
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Description
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-----------
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i2c-ocores is an i2c bus driver for the OpenCores.org I2C controller
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IP core by Richard Herveille.
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Usage
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-----
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i2c-ocores uses the platform bus, so you need to provide a struct
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platform_device with the base address and interrupt number. The
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dev.platform_data of the device should also point to a struct
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ocores_i2c_platform_data (see linux/i2c-ocores.h) describing the
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distance between registers and the input clock speed.
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There is also a possibility to attach a list of i2c_board_info which
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the i2c-ocores driver will add to the bus upon creation.
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E.G. something like:
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static struct resource ocores_resources[] = {
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[0] = {
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.start = MYI2C_BASEADDR,
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.end = MYI2C_BASEADDR + 8,
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.flags = IORESOURCE_MEM,
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},
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[1] = {
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.start = MYI2C_IRQ,
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.end = MYI2C_IRQ,
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.flags = IORESOURCE_IRQ,
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},
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};
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/* optional board info */
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struct i2c_board_info ocores_i2c_board_info[] = {
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{
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I2C_BOARD_INFO("tsc2003", 0x48),
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.platform_data = &tsc2003_platform_data,
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.irq = TSC_IRQ
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},
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{
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I2C_BOARD_INFO("adv7180", 0x42 >> 1),
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.irq = ADV_IRQ
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}
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};
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static struct ocores_i2c_platform_data myi2c_data = {
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.regstep = 2, /* two bytes between registers */
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.clock_khz = 50000, /* input clock of 50MHz */
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.devices = ocores_i2c_board_info, /* optional table of devices */
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.num_devices = ARRAY_SIZE(ocores_i2c_board_info), /* table size */
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};
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static struct platform_device myi2c = {
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.name = "ocores-i2c",
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.dev = {
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.platform_data = &myi2c_data,
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},
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.num_resources = ARRAY_SIZE(ocores_resources),
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.resource = ocores_resources,
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};
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