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