46f555f273
Add command wrappers that simplify register access from SDIO function drivers. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
106 lines
2.4 KiB
C
106 lines
2.4 KiB
C
/*
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* linux/drivers/mmc/core/sdio_io.c
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*
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* Copyright 2007 Pierre Ossman
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*/
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#include <linux/mmc/host.h>
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#include <linux/mmc/card.h>
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#include <linux/mmc/sdio_func.h>
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#include "sdio_ops.h"
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/**
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* sdio_claim_host - exclusively claim a bus for a certain SDIO function
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* @func: SDIO function that will be accessed
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*
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* Claim a bus for a set of operations. The SDIO function given
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* is used to figure out which bus is relevant.
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*/
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void sdio_claim_host(struct sdio_func *func)
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{
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BUG_ON(!func);
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BUG_ON(!func->card);
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mmc_claim_host(func->card->host);
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}
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EXPORT_SYMBOL_GPL(sdio_claim_host);
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/**
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* sdio_release_host - release a bus for a certain SDIO function
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* @func: SDIO function that was accessed
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*
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* Release a bus, allowing others to claim the bus for their
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* operations.
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*/
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void sdio_release_host(struct sdio_func *func)
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{
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BUG_ON(!func);
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BUG_ON(!func->card);
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mmc_release_host(func->card->host);
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}
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EXPORT_SYMBOL_GPL(sdio_release_host);
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/**
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* sdio_readb - read a single byte from a SDIO function
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* @func: SDIO function to access
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* @addr: address to read
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* @err_ret: optional status value from transfer
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*
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* Reads a single byte from the address space of a given SDIO
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* function. If there is a problem reading the address, 0xff
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* is returned and @err_ret will contain the error code.
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*/
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unsigned char sdio_readb(struct sdio_func *func, unsigned int addr,
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int *err_ret)
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{
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int ret;
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unsigned char val;
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BUG_ON(!func);
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if (err_ret)
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*err_ret = 0;
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ret = mmc_io_rw_direct(func->card, 0, func->num, addr, 0, &val);
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if (ret) {
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if (err_ret)
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*err_ret = ret;
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return 0xFF;
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}
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return val;
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}
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EXPORT_SYMBOL_GPL(sdio_readb);
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/**
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* sdio_writeb - write a single byte to a SDIO function
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* @func: SDIO function to access
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* @b: byte to write
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* @addr: address to write to
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* @err_ret: optional status value from transfer
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*
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* Writes a single byte to the address space of a given SDIO
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* function. @err_ret will contain the status of the actual
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* transfer.
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*/
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void sdio_writeb(struct sdio_func *func, unsigned char b, unsigned int addr,
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int *err_ret)
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{
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int ret;
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BUG_ON(!func);
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ret = mmc_io_rw_direct(func->card, 1, func->num, addr, b, NULL);
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if (err_ret)
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*err_ret = ret;
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}
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EXPORT_SYMBOL_GPL(sdio_writeb);
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