+++ /dev/null
-/*
- * Simple bitbanged-GPIO SPI driver for ETRAX FS et al.
- *
- * Copyright (c) 2007 Axis Communications AB
- *
- * Author: Hans-Peter Nilsson, inspired by earlier work by
- * Andre Spanberg but mostly by copying large parts of
- * spi_s3c24xx_gpio.c, hence also:
- * Copyright (c) 2006 Ben Dooks
- * Copyright (c) 2006 Simtec Electronics
- *
- * 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/types.h>
-#include <linux/device.h>
-#include <linux/spi/spi.h>
-#include <linux/spi/spi_bitbang.h>
-#include <linux/delay.h>
-#include <linux/platform_device.h>
-#include <asm/io.h>
-#include <asm/arch/board.h>
-
-/* Our main driver state. */
-
-struct crisv32_spi_hw_info {
- struct crisv32_iopin sclk;
- struct crisv32_iopin mosi;
- struct crisv32_iopin miso;
- struct crisv32_iopin cs;
-};
-
-/*
- * The driver state hides behind the spi_bitbang state. We're
- * responsible for allocating that, so we can get a little something
- * for ourselves.
- */
-
-struct crisv32_spi_gpio_devdata {
- struct spi_bitbang bitbang;
- struct crisv32_spi_hw_info pins;
-};
-
-/* Helper function getting the driver state from a spi_device. */
-
-static inline struct crisv32_spi_hw_info *spidev_to_hw(struct spi_device *spi)
-{
- struct crisv32_spi_gpio_devdata *dd = spi_master_get_devdata(spi->master);
- return &dd->pins;
-}
-
-/* The SPI-bitbang functions: see spi_bitbang.h at EXPAND_BITBANG_TXRX. */
-
-static inline void setsck(struct spi_device *spi, int is_on)
-{
- crisv32_io_set(&spidev_to_hw(spi)->sclk, is_on != 0);
-}
-
-static inline void setmosi(struct spi_device *spi, int is_on)
-{
- crisv32_io_set(&spidev_to_hw(spi)->mosi, is_on != 0);
-}
-
-static inline u32 getmiso(struct spi_device *spi)
-{
- return crisv32_io_rd(&spidev_to_hw(spi)->miso) != 0 ? 1 : 0;
-}
-
-#define spidelay(x) ndelay(x)
-
-#define EXPAND_BITBANG_TXRX
-#include <linux/spi/spi_bitbang.h>
-
-/*
- * SPI-bitbang word transmit-functions for the four SPI modes,
- * dispatching to the inlined functions we just included.
- */
-
-static u32 crisv32_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 crisv32_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 crisv32_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 crisv32_spi_gpio_txrx_mode3(struct spi_device *spi,
- unsigned nsecs, u32 word, u8 bits)
-{
- return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
-}
-
-/* SPI-bitbang chip-select function. */
-
-static void crisv32_spi_gpio_chipselect(struct spi_device *spi, int value)
-{
- if (spi->mode & SPI_CS_HIGH)
- crisv32_io_set(&spidev_to_hw(spi)->cs,
- value == BITBANG_CS_ACTIVE ? 1 : 0);
- else
- crisv32_io_set(&spidev_to_hw(spi)->cs,
- value == BITBANG_CS_ACTIVE ? 0 : 1);
-}
-
-/* Platform-device probe function. */
-
-static int __devinit crisv32_spi_gpio_probe(struct platform_device *dev)
-{
- struct spi_master *master;
- struct crisv32_spi_gpio_devdata *dd;
- struct resource *res;
- struct crisv32_spi_gpio_controller_data *gc;
- int ret = 0;
-
- /*
- * We need to get the controller data as a hardware resource,
- * or else it wouldn't be available until *after* the
- * spi_bitbang_start call!
- */
- res = platform_get_resource_byname(dev, 0, "controller_data_ptr");
- if (res == NULL) {
- dev_err(&dev->dev, "can't get controller_data resource\n");
- return -EIO;
- }
-
- gc = (struct crisv32_spi_gpio_controller_data *) res->start;
-
- master = spi_alloc_master(&dev->dev, sizeof *dd);
- if (master == NULL) {
- dev_err(&dev->dev, "failed to allocate spi master\n");
- ret = -ENOMEM;
- goto err;
- }
-
- dd = spi_master_get_devdata(master);
- platform_set_drvdata(dev, dd);
-
- /*
- * The device data asks for this driver, and holds the id
- * number, which must be unique among the same-type devices.
- * We use this as the number of this SPI bus.
- */
- master->bus_num = dev->id;
-
- /*
- * Allocate pins. Note that thus being allocated as GPIO, we
- * don't have to deconfigure them at the end or if something
- * fails.
- */
- if ((ret = crisv32_io_get_name(&dd->pins.cs, gc->cs)) != 0
- || (ret = crisv32_io_get_name(&dd->pins.miso, gc->miso)) != 0
- || (ret = crisv32_io_get_name(&dd->pins.mosi, gc->mosi)) != 0
- || (ret = crisv32_io_get_name(&dd->pins.sclk, gc->sclk)) != 0)
- goto err_no_pins;
-
- /* Set directions of the SPI pins. */
- crisv32_io_set_dir(&dd->pins.cs, crisv32_io_dir_out);
- crisv32_io_set_dir(&dd->pins.sclk, crisv32_io_dir_out);
- crisv32_io_set_dir(&dd->pins.miso, crisv32_io_dir_in);
- crisv32_io_set_dir(&dd->pins.mosi, crisv32_io_dir_out);
-
- /* Set state of the SPI pins. */
- dev_dbg(&dev->dev, "cs.port 0x%x, pin: %d\n"
- dd->pins.cs.port, dd->pins.cs.bit);
-
- /*
- * Can't use crisv32_spi_gpio_chipselect(spi, 1) here; we
- * don't have a proper "spi" until after spi_bitbang_start.
- */
- crisv32_io_set(&dd->pins.cs, 1);
- crisv32_io_set(&dd->pins.sclk, 0);
- crisv32_io_set(&dd->pins.mosi, 0);
-
- /* Setup SPI bitbang adapter hooks. */
- dd->bitbang.master = spi_master_get(master);
- dd->bitbang.chipselect = crisv32_spi_gpio_chipselect;
-
- dd->bitbang.txrx_word[SPI_MODE_0] = crisv32_spi_gpio_txrx_mode0;
- dd->bitbang.txrx_word[SPI_MODE_1] = crisv32_spi_gpio_txrx_mode1;
- dd->bitbang.txrx_word[SPI_MODE_2] = crisv32_spi_gpio_txrx_mode2;
- dd->bitbang.txrx_word[SPI_MODE_3] = crisv32_spi_gpio_txrx_mode3;
-
- ret = spi_bitbang_start(&dd->bitbang);
- if (ret)
- goto err_no_bitbang;
-
- printk (KERN_INFO "CRIS v32 SPI driver for GPIO"
- " (cs: %s, miso: %s, mosi: %s, sclk: %s)\n",
- gc->cs, gc->miso, gc->mosi, gc->sclk);
-
- return 0;
-
- err_no_bitbang:
- spi_master_put(dd->bitbang.master);
- err_no_pins:
- platform_set_drvdata(dev, NULL);
- err:
- return ret;
-}
-
-/* Platform-device remove-function. */
-
-static int __devexit crisv32_spi_gpio_remove(struct platform_device *dev)
-{
- struct crisv32_spi_gpio_devdata *dd = platform_get_drvdata(dev);
- int ret;
-
- ret = spi_bitbang_stop(&dd->bitbang);
- if (ret != 0)
- return ret;
-
- spi_master_put(dd->bitbang.master);
- platform_set_drvdata(dev, NULL);
- return 0;
-}
-
-/*
- * For the time being, there's no suspend/resume support to care
- * about, so we let those handlers default to NULL.
- */
-static struct platform_driver crisv32_spi_gpio_drv = {
- .probe = crisv32_spi_gpio_probe,
- .remove = __devexit_p(crisv32_spi_gpio_remove),
- .driver = {
- .name = "spi_crisv32_gpio",
- .owner = THIS_MODULE,
- },
-};
-
-/* Module init function. */
-
-static int __devinit crisv32_spi_gpio_init(void)
-{
- return platform_driver_register(&crisv32_spi_gpio_drv);
-}
-
-/* Module exit function. */
-
-static void __devexit crisv32_spi_gpio_exit(void)
-{
- platform_driver_unregister(&crisv32_spi_gpio_drv);
-}
-
-module_init(crisv32_spi_gpio_init);
-module_exit(crisv32_spi_gpio_exit);
-
-MODULE_DESCRIPTION("CRIS v32 SPI-GPIO Driver");
-MODULE_AUTHOR("Hans-Peter Nilsson, <hp@axis.com>");
-MODULE_LICENSE("GPL");
projects / openwrt / svn-archive / archive.git / blobdiff