/* * Atheros AP83 board specific SPI Controller driver * * Copyright (C) 2009 Gabor Juhos * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #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 #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 "); MODULE_LICENSE("GPL v2");