diff options
Diffstat (limited to 'target/linux/ubicom32/files/drivers/spi/spi_ubicom32_gpio.c')
| -rw-r--r-- | target/linux/ubicom32/files/drivers/spi/spi_ubicom32_gpio.c | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/target/linux/ubicom32/files/drivers/spi/spi_ubicom32_gpio.c b/target/linux/ubicom32/files/drivers/spi/spi_ubicom32_gpio.c new file mode 100644 index 000000000..c41018a26 --- /dev/null +++ b/target/linux/ubicom32/files/drivers/spi/spi_ubicom32_gpio.c @@ -0,0 +1,267 @@ +/* + * 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"); |