diff options
Diffstat (limited to 'target/linux/ar71xx/files/drivers/spi/spi-ap83.c')
| -rw-r--r-- | target/linux/ar71xx/files/drivers/spi/spi-ap83.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/target/linux/ar71xx/files/drivers/spi/spi-ap83.c b/target/linux/ar71xx/files/drivers/spi/spi-ap83.c new file mode 100644 index 000000000..33843a6da --- /dev/null +++ b/target/linux/ar71xx/files/drivers/spi/spi-ap83.c @@ -0,0 +1,283 @@ +/* + * Atheros AP83 board specific SPI Controller driver + * + * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org> + * + * 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/module.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/bitops.h> +#include <linux/gpio.h> + +#include <asm/mach-ath79/ath79.h> + +#define DRV_DESC "Atheros AP83 board SPI Controller driver" +#define DRV_VERSION "0.1.0" +#define DRV_NAME "ap83-spi" + +#define AP83_SPI_CLK_HIGH (1 << 23) +#define AP83_SPI_CLK_LOW 0 +#define AP83_SPI_MOSI_HIGH (1 << 22) +#define AP83_SPI_MOSI_LOW 0 + +#define AP83_SPI_GPIO_CS 1 +#define AP83_SPI_GPIO_MISO 3 + +struct ap83_spi { + struct spi_bitbang bitbang; + void __iomem *base; + u32 addr; + + struct platform_device *pdev; +}; + +static inline u32 ap83_spi_rr(struct ap83_spi *sp, u32 reg) +{ + return __raw_readl(sp->base + reg); +} + +static inline struct ap83_spi *spidev_to_sp(struct spi_device *spi) +{ + return spi_master_get_devdata(spi->master); +} + +static inline void setsck(struct spi_device *spi, int val) +{ + struct ap83_spi *sp = spidev_to_sp(spi); + + if (val) + sp->addr |= AP83_SPI_CLK_HIGH; + else + sp->addr &= ~AP83_SPI_CLK_HIGH; + + dev_dbg(&spi->dev, "addr=%08x, SCK set to %s\n", + sp->addr, (val) ? "HIGH" : "LOW"); + + ap83_spi_rr(sp, sp->addr); +} + +static inline void setmosi(struct spi_device *spi, int val) +{ + struct ap83_spi *sp = spidev_to_sp(spi); + + if (val) + sp->addr |= AP83_SPI_MOSI_HIGH; + else + sp->addr &= ~AP83_SPI_MOSI_HIGH; + + dev_dbg(&spi->dev, "addr=%08x, MOSI set to %s\n", + sp->addr, (val) ? "HIGH" : "LOW"); + + ap83_spi_rr(sp, sp->addr); +} + +static inline u32 getmiso(struct spi_device *spi) +{ + u32 ret; + + ret = gpio_get_value(AP83_SPI_GPIO_MISO) ? 1 : 0; + dev_dbg(&spi->dev, "get MISO: %d\n", ret); + + return ret; +} + +static inline void do_spidelay(struct spi_device *spi, unsigned nsecs) +{ + ndelay(nsecs); +} + +static void ap83_spi_chipselect(struct spi_device *spi, int on) +{ + struct ap83_spi *sp = spidev_to_sp(spi); + + dev_dbg(&spi->dev, "set CS to %d\n", (on) ? 0 : 1); + + if (on) { + ath79_flash_acquire(); + + sp->addr = 0; + ap83_spi_rr(sp, sp->addr); + + gpio_set_value(AP83_SPI_GPIO_CS, 0); + } else { + gpio_set_value(AP83_SPI_GPIO_CS, 1); + ath79_flash_release(); + } +} + +#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> +#include "spi-bitbang-txrx.h" + +static u32 ap83_spi_txrx_mode0(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + dev_dbg(&spi->dev, "TXRX0 word=%08x, bits=%u\n", word, bits); + return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); +} + +static u32 ap83_spi_txrx_mode1(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + dev_dbg(&spi->dev, "TXRX1 word=%08x, bits=%u\n", word, bits); + return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits); +} + +static u32 ap83_spi_txrx_mode2(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + dev_dbg(&spi->dev, "TXRX2 word=%08x, bits=%u\n", word, bits); + return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits); +} + +static u32 ap83_spi_txrx_mode3(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + dev_dbg(&spi->dev, "TXRX3 word=%08x, bits=%u\n", word, bits); + return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits); +} + +static int ap83_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct ap83_spi *sp; + struct ap83_spi_platform_data *pdata; + struct resource *r; + int ret; + + ret = gpio_request(AP83_SPI_GPIO_MISO, "spi-miso"); + if (ret) { + dev_err(&pdev->dev, "gpio request failed for MISO\n"); + return ret; + } + + ret = gpio_request(AP83_SPI_GPIO_CS, "spi-cs"); + if (ret) { + dev_err(&pdev->dev, "gpio request failed for CS\n"); + goto err_free_miso; + } + + ret = gpio_direction_input(AP83_SPI_GPIO_MISO); + if (ret) { + dev_err(&pdev->dev, "unable to set direction of MISO\n"); + goto err_free_cs; + } + + ret = gpio_direction_output(AP83_SPI_GPIO_CS, 0); + if (ret) { + dev_err(&pdev->dev, "unable to set direction of CS\n"); + goto err_free_cs; + } + + master = spi_alloc_master(&pdev->dev, sizeof(*sp)); + if (master == NULL) { + dev_err(&pdev->dev, "failed to allocate spi master\n"); + return -ENOMEM; + } + + sp = spi_master_get_devdata(master); + platform_set_drvdata(pdev, sp); + + pdata = pdev->dev.platform_data; + + sp->bitbang.master = spi_master_get(master); + sp->bitbang.chipselect = ap83_spi_chipselect; + sp->bitbang.txrx_word[SPI_MODE_0] = ap83_spi_txrx_mode0; + sp->bitbang.txrx_word[SPI_MODE_1] = ap83_spi_txrx_mode1; + sp->bitbang.txrx_word[SPI_MODE_2] = ap83_spi_txrx_mode2; + sp->bitbang.txrx_word[SPI_MODE_3] = ap83_spi_txrx_mode3; + + sp->bitbang.master->bus_num = pdev->id; + sp->bitbang.master->num_chipselect = 1; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + ret = -ENOENT; + goto err_spi_put; + } + + sp->base = ioremap_nocache(r->start, r->end - r->start + 1); + if (!sp->base) { + ret = -ENXIO; + goto err_spi_put; + } + + ret = spi_bitbang_start(&sp->bitbang); + if (!ret) + goto err_unmap; + + dev_info(&pdev->dev, "AP83 SPI adapter at %08x\n", r->start); + + return 0; + +err_unmap: + iounmap(sp->base); +err_spi_put: + platform_set_drvdata(pdev, NULL); + spi_master_put(sp->bitbang.master); + +err_free_cs: + gpio_free(AP83_SPI_GPIO_CS); +err_free_miso: + gpio_free(AP83_SPI_GPIO_MISO); + return ret; +} + +static int ap83_spi_remove(struct platform_device *pdev) +{ + struct ap83_spi *sp = platform_get_drvdata(pdev); + + spi_bitbang_stop(&sp->bitbang); + iounmap(sp->base); + platform_set_drvdata(pdev, NULL); + spi_master_put(sp->bitbang.master); + + return 0; +} + +static struct platform_driver ap83_spi_drv = { + .probe = ap83_spi_probe, + .remove = ap83_spi_remove, + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init ap83_spi_init(void) +{ + return platform_driver_register(&ap83_spi_drv); +} +module_init(ap83_spi_init); + +static void __exit ap83_spi_exit(void) +{ + platform_driver_unregister(&ap83_spi_drv); +} +module_exit(ap83_spi_exit); + +MODULE_ALIAS("platform:" DRV_NAME); +MODULE_DESCRIPTION(DRV_DESC); +MODULE_VERSION(DRV_VERSION); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_LICENSE("GPL v2"); |