+++ /dev/null
-/*
- * Bitbanging SPI bus driver using GPIO API
- *
- * Copyright (c) 2008 Piotr Skamruk
- * Copyright (c) 2008 Michael Buesch
- *
- * based on spi_s3c2410_gpio.c
- * Copyright (c) 2006 Ben Dooks
- * Copyright (c) 2006 Simtec Electronics
- * and on i2c-gpio.c
- * Copyright (C) 2007 Atmel Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/spinlock.h>
-#include <linux/workqueue.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/spi/spi.h>
-#include <linux/spi/spi_bitbang.h>
-#include "linux/spi/spi_gpio.h" //XXX
-#include <asm/gpio.h>
-
-
-struct spi_gpio {
- struct spi_bitbang bitbang;
- struct spi_gpio_platform_data *info;
- struct platform_device *pdev;
- struct spi_board_info bi;
-};
-
-
-static inline struct spi_gpio *spidev_to_sg(struct spi_device *dev)
-{
- return dev->controller_data;
-}
-
-static inline void setsck(struct spi_device *dev, int val)
-{
- struct spi_gpio *sp = spidev_to_sg(dev);
- gpio_set_value(sp->info->pin_clk, val ? 1 : 0);
-}
-
-static inline void setmosi(struct spi_device *dev, int val )
-{
- struct spi_gpio *sp = spidev_to_sg(dev);
- gpio_set_value(sp->info->pin_mosi, val ? 1 : 0);
-}
-
-static inline u32 getmiso(struct spi_device *dev)
-{
- struct spi_gpio *sp = spidev_to_sg(dev);
- return gpio_get_value(sp->info->pin_miso) ? 1 : 0;
-}
-
-static inline void do_spidelay(struct spi_device *dev, unsigned nsecs)
-{
- struct spi_gpio *sp = spidev_to_sg(dev);
-
- if (!sp->info->no_spi_delay)
- ndelay(nsecs);
-}
-
-#define spidelay(nsecs) do { \
- /* Steal the spi_device pointer from our caller. \
- * The bitbang-API should probably get fixed here... */ \
- do_spidelay(spi, nsecs); \
- } while (0)
-
-#define EXPAND_BITBANG_TXRX
-#include <linux/spi/spi_bitbang.h>
-
-static u32 spi_gpio_txrx_mode0(struct spi_device *spi,
- unsigned nsecs, u32 word, u8 bits)
-{
- return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
-}
-
-static u32 spi_gpio_txrx_mode1(struct spi_device *spi,
- unsigned nsecs, u32 word, u8 bits)
-{
- return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
-}
-
-static u32 spi_gpio_txrx_mode2(struct spi_device *spi,
- unsigned nsecs, u32 word, u8 bits)
-{
- return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
-}
-
-static u32 spi_gpio_txrx_mode3(struct spi_device *spi,
- unsigned nsecs, u32 word, u8 bits)
-{
- return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
-}
-
-static void spi_gpio_chipselect(struct spi_device *dev, int on)
-{
- struct spi_gpio *sp = spidev_to_sg(dev);
-
- if (sp->info->cs_activelow)
- on = !on;
- gpio_set_value(sp->info->pin_cs, on ? 1 : 0);
-}
-
-static int spi_gpio_probe(struct platform_device *pdev)
-{
- struct spi_master *master;
- struct spi_gpio_platform_data *pdata;
- struct spi_gpio *sp;
- struct spi_device *spidev;
- int err;
-
- pdata = pdev->dev.platform_data;
- if (!pdata)
- return -ENXIO;
-
- err = -ENOMEM;
- master = spi_alloc_master(&pdev->dev, sizeof(struct spi_gpio));
- if (!master)
- goto err_alloc_master;
-
- sp = spi_master_get_devdata(master);
- platform_set_drvdata(pdev, sp);
- sp->info = pdata;
-
- err = gpio_request(pdata->pin_clk, "spi_clock");
- if (err)
- goto err_request_clk;
- err = gpio_request(pdata->pin_mosi, "spi_mosi");
- if (err)
- goto err_request_mosi;
- err = gpio_request(pdata->pin_miso, "spi_miso");
- if (err)
- goto err_request_miso;
- err = gpio_request(pdata->pin_cs, "spi_cs");
- if (err)
- goto err_request_cs;
-
- sp->bitbang.master = spi_master_get(master);
- sp->bitbang.master->bus_num = -1;
- sp->bitbang.master->num_chipselect = 1;
- sp->bitbang.chipselect = spi_gpio_chipselect;
- sp->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_mode0;
- sp->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_mode1;
- sp->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_mode2;
- sp->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_mode3;
-
- gpio_direction_output(pdata->pin_clk, 0);
- gpio_direction_output(pdata->pin_mosi, 0);
- gpio_direction_output(pdata->pin_cs,
- pdata->cs_activelow ? 1 : 0);
- gpio_direction_input(pdata->pin_miso);
-
- err = spi_bitbang_start(&sp->bitbang);
- if (err)
- goto err_no_bitbang;
- err = pdata->boardinfo_setup(&sp->bi, master,
- pdata->boardinfo_setup_data);
- if (err)
- goto err_bi_setup;
- sp->bi.controller_data = sp;
- spidev = spi_new_device(master, &sp->bi);
- if (!spidev)
- goto err_new_dev;
-
- return 0;
-
-err_new_dev:
-err_bi_setup:
- spi_bitbang_stop(&sp->bitbang);
-err_no_bitbang:
- spi_master_put(sp->bitbang.master);
- gpio_free(pdata->pin_cs);
-err_request_cs:
- gpio_free(pdata->pin_miso);
-err_request_miso:
- gpio_free(pdata->pin_mosi);
-err_request_mosi:
- gpio_free(pdata->pin_clk);
-err_request_clk:
- kfree(master);
-
-err_alloc_master:
- return err;
-}
-
-static int __devexit spi_gpio_remove(struct platform_device *pdev)
-{
- struct spi_gpio *sp;
- struct spi_gpio_platform_data *pdata;
-
- pdata = pdev->dev.platform_data;
- sp = platform_get_drvdata(pdev);
-
- gpio_free(pdata->pin_clk);
- gpio_free(pdata->pin_mosi);
- gpio_free(pdata->pin_miso);
- gpio_free(pdata->pin_cs);
- spi_bitbang_stop(&sp->bitbang);
- spi_master_put(sp->bitbang.master);
-
- return 0;
-}
-
-static struct platform_driver spi_gpio_driver = {
- .driver = {
- .name = "spi-gpio",
- .owner = THIS_MODULE,
- },
- .probe = spi_gpio_probe,
- .remove = __devexit_p(spi_gpio_remove),
-};
-
-static int __init spi_gpio_init(void)
-{
- int err;
-
- err = platform_driver_register(&spi_gpio_driver);
- if (err)
- printk(KERN_ERR "spi-gpio: register failed: %d\n", err);
-
- return err;
-}
-module_init(spi_gpio_init);
-
-static void __exit spi_gpio_exit(void)
-{
- platform_driver_unregister(&spi_gpio_driver);
-}
-module_exit(spi_gpio_exit);
-
-MODULE_AUTHOR("Piot Skamruk <piotr.skamruk at gmail.com>");
-MODULE_AUTHOR("Michael Buesch");
-MODULE_DESCRIPTION("Platform independent GPIO bitbangling SPI driver");
-MODULE_LICENSE("GPL v2");
projects / openwrt / svn-archive / archive.git / blobdiff