117 lines
3.0 KiB
C
117 lines
3.0 KiB
C
/*
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* linux/arch/arm/plat-omap/i2c.c
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*
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* Helper module for board specific I2C bus registration
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*
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* Copyright (C) 2007 Nokia Corporation.
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*
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* Contact: Jarkko Nikula <jhnikula@gmail.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*
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*/
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/i2c.h>
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#include <linux/i2c-omap.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <plat/i2c.h>
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#define OMAP_I2C_MAX_CONTROLLERS 4
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static struct omap_i2c_bus_platform_data i2c_pdata[OMAP_I2C_MAX_CONTROLLERS];
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#define OMAP_I2C_CMDLINE_SETUP (BIT(31))
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/**
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* omap_i2c_bus_setup - Process command line options for the I2C bus speed
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* @str: String of options
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*
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* This function allow to override the default I2C bus speed for given I2C
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* bus with a command line option.
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*
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* Format: i2c_bus=bus_id,clkrate (in kHz)
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*
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* Returns 1 on success, 0 otherwise.
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*/
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static int __init omap_i2c_bus_setup(char *str)
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{
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int ints[3];
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get_options(str, 3, ints);
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if (ints[0] < 2 || ints[1] < 1 ||
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ints[1] > OMAP_I2C_MAX_CONTROLLERS)
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return 0;
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i2c_pdata[ints[1] - 1].clkrate = ints[2];
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i2c_pdata[ints[1] - 1].clkrate |= OMAP_I2C_CMDLINE_SETUP;
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return 1;
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}
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__setup("i2c_bus=", omap_i2c_bus_setup);
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/*
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* Register busses defined in command line but that are not registered with
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* omap_register_i2c_bus from board initialization code.
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*/
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int __init omap_register_i2c_bus_cmdline(void)
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{
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int i, err = 0;
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for (i = 0; i < ARRAY_SIZE(i2c_pdata); i++)
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if (i2c_pdata[i].clkrate & OMAP_I2C_CMDLINE_SETUP) {
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i2c_pdata[i].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
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err = omap_i2c_add_bus(&i2c_pdata[i], i + 1);
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if (err)
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goto out;
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}
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out:
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return err;
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}
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/**
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* omap_register_i2c_bus - register I2C bus with device descriptors
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* @bus_id: bus id counting from number 1
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* @clkrate: clock rate of the bus in kHz
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* @info: pointer into I2C device descriptor table or NULL
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* @len: number of descriptors in the table
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*
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* Returns 0 on success or an error code.
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*/
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int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
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struct i2c_board_info const *info,
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unsigned len)
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{
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int err;
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BUG_ON(bus_id < 1 || bus_id > OMAP_I2C_MAX_CONTROLLERS);
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if (info) {
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err = i2c_register_board_info(bus_id, info, len);
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if (err)
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return err;
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}
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if (!i2c_pdata[bus_id - 1].clkrate)
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i2c_pdata[bus_id - 1].clkrate = clkrate;
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i2c_pdata[bus_id - 1].clkrate &= ~OMAP_I2C_CMDLINE_SETUP;
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return omap_i2c_add_bus(&i2c_pdata[bus_id - 1], bus_id);
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}
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