1/* 2 * Atheros AP83 board specific SPI Controller driver 3 * 4 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 */ 11 12#include <linux/kernel.h> 13#include <linux/module.h> 14#include <linux/init.h> 15#include <linux/delay.h> 16#include <linux/spinlock.h> 17#include <linux/workqueue.h> 18#include <linux/platform_device.h> 19#include <linux/io.h> 20#include <linux/spi/spi.h> 21#include <linux/spi/spi_bitbang.h> 22#include <linux/bitops.h> 23#include <linux/gpio.h> 24 25#include <asm/mach-ath79/ath79.h> 26 27#define DRV_DESC "Atheros AP83 board SPI Controller driver" 28#define DRV_VERSION "0.1.0" 29#define DRV_NAME "ap83-spi" 30 31#define AP83_SPI_CLK_HIGH (1 << 23) 32#define AP83_SPI_CLK_LOW 0 33#define AP83_SPI_MOSI_HIGH (1 << 22) 34#define AP83_SPI_MOSI_LOW 0 35 36#define AP83_SPI_GPIO_CS 1 37#define AP83_SPI_GPIO_MISO 3 38 39struct ap83_spi { 40 struct spi_bitbang bitbang; 41 void __iomem *base; 42 u32 addr; 43 44 struct platform_device *pdev; 45}; 46 47static inline u32 ap83_spi_rr(struct ap83_spi *sp, u32 reg) 48{ 49 return __raw_readl(sp->base + reg); 50} 51 52static inline struct ap83_spi *spidev_to_sp(struct spi_device *spi) 53{ 54 return spi_master_get_devdata(spi->master); 55} 56 57static inline void setsck(struct spi_device *spi, int val) 58{ 59 struct ap83_spi *sp = spidev_to_sp(spi); 60 61 if (val) 62 sp->addr |= AP83_SPI_CLK_HIGH; 63 else 64 sp->addr &= ~AP83_SPI_CLK_HIGH; 65 66 dev_dbg(&spi->dev, "addr=%08x, SCK set to %s\n", 67 sp->addr, (val) ? "HIGH" : "LOW"); 68 69 ap83_spi_rr(sp, sp->addr); 70} 71 72static inline void setmosi(struct spi_device *spi, int val) 73{ 74 struct ap83_spi *sp = spidev_to_sp(spi); 75 76 if (val) 77 sp->addr |= AP83_SPI_MOSI_HIGH; 78 else 79 sp->addr &= ~AP83_SPI_MOSI_HIGH; 80 81 dev_dbg(&spi->dev, "addr=%08x, MOSI set to %s\n", 82 sp->addr, (val) ? "HIGH" : "LOW"); 83 84 ap83_spi_rr(sp, sp->addr); 85} 86 87static inline u32 getmiso(struct spi_device *spi) 88{ 89 u32 ret; 90 91 ret = gpio_get_value(AP83_SPI_GPIO_MISO) ? 1 : 0; 92 dev_dbg(&spi->dev, "get MISO: %d\n", ret); 93 94 return ret; 95} 96 97static inline void do_spidelay(struct spi_device *spi, unsigned nsecs) 98{ 99 ndelay(nsecs); 100} 101 102static void ap83_spi_chipselect(struct spi_device *spi, int on) 103{ 104 struct ap83_spi *sp = spidev_to_sp(spi); 105 106 dev_dbg(&spi->dev, "set CS to %d\n", (on) ? 0 : 1); 107 108 if (on) { 109 ath79_flash_acquire(); 110 111 sp->addr = 0; 112 ap83_spi_rr(sp, sp->addr); 113 114 gpio_set_value(AP83_SPI_GPIO_CS, 0); 115 } else { 116 gpio_set_value(AP83_SPI_GPIO_CS, 1); 117 ath79_flash_release(); 118 } 119} 120 121#define spidelay(nsecs) \ 122 do { \ 123 /* Steal the spi_device pointer from our caller. \ 124 * The bitbang-API should probably get fixed here... */ \ 125 do_spidelay(spi, nsecs); \ 126 } while (0) 127 128#define EXPAND_BITBANG_TXRX 129#include <linux/spi/spi_bitbang.h> 130#include "spi-bitbang-txrx.h" 131 132static u32 ap83_spi_txrx_mode0(struct spi_device *spi, 133 unsigned nsecs, u32 word, u8 bits) 134{ 135 dev_dbg(&spi->dev, "TXRX0 word=%08x, bits=%u\n", word, bits); 136 return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); 137} 138 139static u32 ap83_spi_txrx_mode1(struct spi_device *spi, 140 unsigned nsecs, u32 word, u8 bits) 141{ 142 dev_dbg(&spi->dev, "TXRX1 word=%08x, bits=%u\n", word, bits); 143 return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits); 144} 145 146static u32 ap83_spi_txrx_mode2(struct spi_device *spi, 147 unsigned nsecs, u32 word, u8 bits) 148{ 149 dev_dbg(&spi->dev, "TXRX2 word=%08x, bits=%u\n", word, bits); 150 return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits); 151} 152 153static u32 ap83_spi_txrx_mode3(struct spi_device *spi, 154 unsigned nsecs, u32 word, u8 bits) 155{ 156 dev_dbg(&spi->dev, "TXRX3 word=%08x, bits=%u\n", word, bits); 157 return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits); 158} 159 160static int ap83_spi_probe(struct platform_device *pdev) 161{ 162 struct spi_master *master; 163 struct ap83_spi *sp; 164 struct ap83_spi_platform_data *pdata; 165 struct resource *r; 166 int ret; 167 168 ret = gpio_request(AP83_SPI_GPIO_MISO, "spi-miso"); 169 if (ret) { 170 dev_err(&pdev->dev, "gpio request failed for MISO\n"); 171 return ret; 172 } 173 174 ret = gpio_request(AP83_SPI_GPIO_CS, "spi-cs"); 175 if (ret) { 176 dev_err(&pdev->dev, "gpio request failed for CS\n"); 177 goto err_free_miso; 178 } 179 180 ret = gpio_direction_input(AP83_SPI_GPIO_MISO); 181 if (ret) { 182 dev_err(&pdev->dev, "unable to set direction of MISO\n"); 183 goto err_free_cs; 184 } 185 186 ret = gpio_direction_output(AP83_SPI_GPIO_CS, 0); 187 if (ret) { 188 dev_err(&pdev->dev, "unable to set direction of CS\n"); 189 goto err_free_cs; 190 } 191 192 master = spi_alloc_master(&pdev->dev, sizeof(*sp)); 193 if (master == NULL) { 194 dev_err(&pdev->dev, "failed to allocate spi master\n"); 195 return -ENOMEM; 196 } 197 198 sp = spi_master_get_devdata(master); 199 platform_set_drvdata(pdev, sp); 200 201 pdata = pdev->dev.platform_data; 202 203 sp->bitbang.master = spi_master_get(master); 204 sp->bitbang.chipselect = ap83_spi_chipselect; 205 sp->bitbang.txrx_word[SPI_MODE_0] = ap83_spi_txrx_mode0; 206 sp->bitbang.txrx_word[SPI_MODE_1] = ap83_spi_txrx_mode1; 207 sp->bitbang.txrx_word[SPI_MODE_2] = ap83_spi_txrx_mode2; 208 sp->bitbang.txrx_word[SPI_MODE_3] = ap83_spi_txrx_mode3; 209 210 sp->bitbang.master->bus_num = pdev->id; 211 sp->bitbang.master->num_chipselect = 1; 212 213 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 214 if (r == NULL) { 215 ret = -ENOENT; 216 goto err_spi_put; 217 } 218 219 sp->base = ioremap_nocache(r->start, r->end - r->start + 1); 220 if (!sp->base) { 221 ret = -ENXIO; 222 goto err_spi_put; 223 } 224 225 ret = spi_bitbang_start(&sp->bitbang); 226 if (!ret) 227 goto err_unmap; 228 229 dev_info(&pdev->dev, "AP83 SPI adapter at %08x\n", r->start); 230 231 return 0; 232 233err_unmap: 234 iounmap(sp->base); 235err_spi_put: 236 platform_set_drvdata(pdev, NULL); 237 spi_master_put(sp->bitbang.master); 238 239err_free_cs: 240 gpio_free(AP83_SPI_GPIO_CS); 241err_free_miso: 242 gpio_free(AP83_SPI_GPIO_MISO); 243 return ret; 244} 245 246static int ap83_spi_remove(struct platform_device *pdev) 247{ 248 struct ap83_spi *sp = platform_get_drvdata(pdev); 249 250 spi_bitbang_stop(&sp->bitbang); 251 iounmap(sp->base); 252 platform_set_drvdata(pdev, NULL); 253 spi_master_put(sp->bitbang.master); 254 255 return 0; 256} 257 258static struct platform_driver ap83_spi_drv = { 259 .probe = ap83_spi_probe, 260 .remove = ap83_spi_remove, 261 .driver = { 262 .name = DRV_NAME, 263 .owner = THIS_MODULE, 264 }, 265}; 266 267static int __init ap83_spi_init(void) 268{ 269 return platform_driver_register(&ap83_spi_drv); 270} 271module_init(ap83_spi_init); 272 273static void __exit ap83_spi_exit(void) 274{ 275 platform_driver_unregister(&ap83_spi_drv); 276} 277module_exit(ap83_spi_exit); 278 279MODULE_ALIAS("platform:" DRV_NAME); 280MODULE_DESCRIPTION(DRV_DESC); 281MODULE_VERSION(DRV_VERSION); 282MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); 283MODULE_LICENSE("GPL v2"); 284