mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-12-27 15:05:32 +02:00
1a29ef8e97
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@19815 3c298f89-4303-0410-b956-a3cf2f4a3e73
268 lines
6.5 KiB
C
268 lines
6.5 KiB
C
/*
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* drivers/spi_spi_ubicom32_gpio.c
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* Ubicom32 GPIO based SPI driver
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*
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* (C) Copyright 2009, Ubicom, Inc.
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*
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* This file is part of the Ubicom32 Linux Kernel Port.
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*
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* The Ubicom32 Linux Kernel Port is free software: you can redistribute
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* it and/or modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, either version 2 of the
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* License, or (at your option) any later version.
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*
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* The Ubicom32 Linux Kernel Port is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU 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 the Ubicom32 Linux Kernel Port. If not,
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* see <http://www.gnu.org/licenses/>.
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*
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* Ubicom32 implementation derived from (with many thanks):
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* arch/m68knommu
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* arch/blackfin
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* arch/parisc
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/spinlock.h>
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#include <linux/workqueue.h>
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#include <linux/platform_device.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi_bitbang.h>
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#include <linux/gpio.h>
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#include <asm/ubicom32-spi-gpio.h>
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#define DRIVER_NAME "ubicom32-spi-gpio"
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struct ubicom32_spi_gpio {
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struct spi_bitbang bitbang;
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struct ubicom32_spi_gpio_platform_data *pdata;
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struct platform_device *dev;
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};
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/*
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* The following 4 functions are used by EXPAND_BITBANG_TXRX to bitbang the data out.
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*/
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static inline void setsck(struct spi_device *dev, int on)
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{
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struct ubicom32_spi_gpio *usg = (struct ubicom32_spi_gpio *)spi_master_get_devdata(dev->master);
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gpio_set_value(usg->pdata->pin_clk, on ? 1 : 0);
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}
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static inline void setmosi(struct spi_device *dev, int on)
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{
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struct ubicom32_spi_gpio *usg = (struct ubicom32_spi_gpio *)spi_master_get_devdata(dev->master);
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gpio_set_value(usg->pdata->pin_mosi, on ? 1 : 0);
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}
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static inline u32 getmiso(struct spi_device *dev)
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{
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struct ubicom32_spi_gpio *usg = (struct ubicom32_spi_gpio *)spi_master_get_devdata(dev->master);
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return gpio_get_value(usg->pdata->pin_miso) ? 1 : 0;
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}
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#define spidelay(x) ndelay(x)
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#define EXPAND_BITBANG_TXRX
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#include <linux/spi/spi_bitbang.h>
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/*
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* ubicom32_spi_gpio_txrx_mode0
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*/
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static u32 ubicom32_spi_gpio_txrx_mode0(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
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{
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return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
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}
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/*
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* ubicom32_spi_gpio_txrx_mode1
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*/
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static u32 ubicom32_spi_gpio_txrx_mode1(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
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{
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return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
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}
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/*
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* ubicom32_spi_gpio_txrx_mode2
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*/
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static u32 ubicom32_spi_gpio_txrx_mode2(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
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{
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return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
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}
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/*
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* ubicom32_spi_gpio_txrx_mode3
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*/
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static u32 ubicom32_spi_gpio_txrx_mode3(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
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{
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return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
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}
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/*
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* ubicom32_spi_gpio_chipselect
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*/
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static void ubicom32_spi_gpio_chipselect(struct spi_device *dev, int value)
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{
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struct ubicom32_spi_gpio_controller_data *cd = (struct ubicom32_spi_gpio_controller_data *)dev->controller_data;
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unsigned int cs_polarity = dev->mode & SPI_CS_HIGH ? 1 : 0;
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if (value == BITBANG_CS_ACTIVE) {
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gpio_set_value(cd->pin_cs, cs_polarity);
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return;
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}
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gpio_set_value(cd->pin_cs, !cs_polarity);
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}
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/*
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* ubicom32_spi_gpio_probe
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*/
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static int ubicom32_spi_gpio_probe(struct platform_device *dev)
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{
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struct ubicom32_spi_gpio_platform_data *pdata;
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struct spi_master *master;
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struct ubicom32_spi_gpio *usg;
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int ret;
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master = spi_alloc_master(&dev->dev, sizeof(struct ubicom32_spi_gpio));
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if (master == NULL) {
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dev_err(&dev->dev, "failed to allocate spi master\n");
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ret = -ENOMEM;
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goto err;
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}
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usg = (struct ubicom32_spi_gpio *)spi_master_get_devdata(master);
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platform_set_drvdata(dev, usg);
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/*
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* Copy in the platform data
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*/
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pdata = dev->dev.platform_data;
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usg->pdata = dev->dev.platform_data;
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/*
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* Request the GPIO lines
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*/
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ret = gpio_request(pdata->pin_mosi, "spi-mosi");
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if (ret) {
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dev_err(&dev->dev, "Failed to allocate spi-mosi GPIO\n");
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goto err;
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}
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ret = gpio_request(pdata->pin_miso, "spi-miso");
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if (ret) {
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dev_err(&dev->dev, "Failed to allocate spi-miso GPIO\n");
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goto err_nomiso;
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}
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ret = gpio_request(pdata->pin_clk, "spi-clk");
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if (ret) {
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dev_err(&dev->dev, "Failed to allocate spi-clk GPIO\n");
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goto err_noclk;
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}
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/*
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* Setup spi-bitbang adaptor
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*/
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usg->bitbang.flags |= SPI_CS_HIGH;
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usg->bitbang.master = spi_master_get(master);
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usg->bitbang.master->bus_num = pdata->bus_num;
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usg->bitbang.master->num_chipselect = pdata->num_chipselect;
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usg->bitbang.chipselect = ubicom32_spi_gpio_chipselect;
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usg->bitbang.txrx_word[SPI_MODE_0] = ubicom32_spi_gpio_txrx_mode0;
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usg->bitbang.txrx_word[SPI_MODE_1] = ubicom32_spi_gpio_txrx_mode1;
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usg->bitbang.txrx_word[SPI_MODE_2] = ubicom32_spi_gpio_txrx_mode2;
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usg->bitbang.txrx_word[SPI_MODE_3] = ubicom32_spi_gpio_txrx_mode3;
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/*
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* Setup the GPIO pins
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*/
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gpio_direction_output(pdata->pin_clk, pdata->clk_default);
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gpio_direction_output(pdata->pin_mosi, 0);
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gpio_direction_input(pdata->pin_miso);
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/*
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* Ready to go
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*/
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ret = spi_bitbang_start(&usg->bitbang);
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if (ret) {
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goto err_no_bitbang;
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}
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return 0;
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err_no_bitbang:
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spi_master_put(usg->bitbang.master);
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gpio_free(pdata->pin_clk);
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err_noclk:
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gpio_free(pdata->pin_miso);
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err_nomiso:
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gpio_free(pdata->pin_mosi);
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err:
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return ret;
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}
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/*
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* ubicom32_spi_gpio_remove
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*/
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static int ubicom32_spi_gpio_remove(struct platform_device *dev)
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{
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struct ubicom32_spi_gpio *sp = platform_get_drvdata(dev);
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spi_bitbang_stop(&sp->bitbang);
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spi_master_put(sp->bitbang.master);
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return 0;
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}
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/*
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* Work with hotplug and coldplug
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*/
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MODULE_ALIAS("platform:ubicom32_spi_gpio");
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static struct platform_driver ubicom32_spi_gpio_drv = {
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.probe = ubicom32_spi_gpio_probe,
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.remove = ubicom32_spi_gpio_remove,
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.driver = {
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.name = DRIVER_NAME,
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.owner = THIS_MODULE,
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},
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};
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/*
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* ubicom32_spi_gpio_init
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*/
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static int __init ubicom32_spi_gpio_init(void)
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{
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return platform_driver_register(&ubicom32_spi_gpio_drv);
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}
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/*
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* ubicom32_spi_gpio_exit
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*/
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static void __exit ubicom32_spi_gpio_exit(void)
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{
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platform_driver_unregister(&ubicom32_spi_gpio_drv);
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}
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module_init(ubicom32_spi_gpio_init);
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module_exit(ubicom32_spi_gpio_exit);
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MODULE_DESCRIPTION("Ubicom32 SPI-GPIO Driver");
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MODULE_AUTHOR("Pat Tjin, <@ubicom.com>");
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MODULE_LICENSE("GPL");
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