target/linux/generic-2.6/patches-2.6.25/921-gpio_spi_driver.patch

   1 Index: linux-2.6.25.17/include/linux/spi/spi_gpio.h
   2 ===================================================================
   3 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
   4 +++ linux-2.6.25.17/include/linux/spi/spi_gpio.h        2008-10-18 23:32:31.000000000 +0200
   5 @@ -0,0 +1,72 @@
   6 +/*
   7 + * spi_gpio interface to platform code
   8 + *
   9 + * Copyright (c) 2008 Piotr Skamruk
  10 + *
  11 + * This program is free software; you can redistribute it and/or modify
  12 + * it under the terms of the GNU General Public License version 2 as
  13 + * published by the Free Software Foundation.
  14 + */
  15 +#ifndef _LINUX_SPI_SPI_GPIO
  16 +#define _LINUX_SPI_SPI_GPIO
  17 +
  18 +#include <linux/types.h>
  19 +#include <linux/spi/spi.h>
  20 +
  21 +
  22 +/**
  23 + * struct spi_gpio_platform_data - Data definitions for a SPI-GPIO device.
  24 + *
  25 + * This structure holds information about a GPIO-based SPI device.
  26 + *
  27 + * @pin_clk: The GPIO pin number of the CLOCK pin.
  28 + *
  29 + * @pin_miso: The GPIO pin number of the MISO pin.
  30 + *
  31 + * @pin_mosi: The GPIO pin number of the MOSI pin.
  32 + *
  33 + * @pin_cs: The GPIO pin number of the CHIPSELECT pin.
  34 + *
  35 + * @cs_activelow: If true, the chip is selected when the CS line is low.
  36 + *
  37 + * @no_spi_delay: If true, no delay is done in the lowlevel bitbanging.
  38 + *                Note that doing no delay is not standards compliant,
  39 + *                but it might be needed to speed up transfers on some
  40 + *                slow embedded machines.
  41 + *
  42 + * @boardinfo_setup: This callback is called after the
  43 + *                   SPI master device was registered, but before the
  44 + *                   device is registered.
  45 + * @boardinfo_setup_data: Data argument passed to boardinfo_setup().
  46 + */
  47 +struct spi_gpio_platform_data {
  48 +       unsigned int pin_clk;
  49 +       unsigned int pin_miso;
  50 +       unsigned int pin_mosi;
  51 +       unsigned int pin_cs;
  52 +       bool cs_activelow;
  53 +       bool no_spi_delay;
  54 +       int (*boardinfo_setup)(struct spi_board_info *bi,
  55 +                              struct spi_master *master,
  56 +                              void *data);
  57 +       void *boardinfo_setup_data;
  58 +};
  59 +
  60 +/**
  61 + * SPI_GPIO_PLATDEV_NAME - The platform device name string.
  62 + *
  63 + * The name string that has to be used for platform_device_alloc
  64 + * when allocating a spi-gpio device.
  65 + */
  66 +#define SPI_GPIO_PLATDEV_NAME  "spi-gpio"
  67 +
  68 +/**
  69 + * spi_gpio_next_id - Get another platform device ID number.
  70 + *
  71 + * This returns the next platform device ID number that has to be used
  72 + * for platform_device_alloc. The ID is opaque and should not be used for
  73 + * anything else.
  74 + */
  75 +int spi_gpio_next_id(void);
  76 +
  77 +#endif /* _LINUX_SPI_SPI_GPIO */
  78 Index: linux-2.6.25.17/drivers/spi/spi_gpio.c
  79 ===================================================================
  80 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  81 +++ linux-2.6.25.17/drivers/spi/spi_gpio.c      2008-10-18 23:31:27.000000000 +0200
  82 @@ -0,0 +1,249 @@
  83 +/*
  84 + * Bitbanging SPI bus driver using GPIO API
  85 + *
  86 + * Copyright (c) 2008 Piotr Skamruk
  87 + *
  88 + * based on spi_s3c2410_gpio.c
  89 + *   Copyright (c) 2006 Ben Dooks
  90 + *   Copyright (c) 2006 Simtec Electronics
  91 + * and on i2c-gpio.c
  92 + *   Copyright (C) 2007 Atmel Corporation
  93 + *
  94 + * This program is free software; you can redistribute it and/or modify
  95 + * it under the terms of the GNU General Public License version 2 as
  96 + * published by the Free Software Foundation.
  97 + */
  98 +
  99 +#include <linux/kernel.h>
 100 +#include <linux/init.h>
 101 +#include <linux/delay.h>
 102 +#include <linux/spinlock.h>
 103 +#include <linux/workqueue.h>
 104 +#include <linux/module.h>
 105 +#include <linux/platform_device.h>
 106 +#include <linux/spi/spi.h>
 107 +#include <linux/spi/spi_bitbang.h>
 108 +#include <linux/spi/spi_gpio.h>
 109 +#include <linux/gpio.h>
 110 +#include <asm/atomic.h>
 111 +
 112 +
 113 +struct spi_gpio {
 114 +       struct spi_bitbang bitbang;
 115 +       struct spi_gpio_platform_data *info;
 116 +       struct platform_device *pdev;
 117 +       struct spi_board_info bi;
 118 +};
 119 +
 120 +
 121 +static inline struct spi_gpio *spidev_to_sg(struct spi_device *dev)
 122 +{
 123 +       return dev->controller_data;
 124 +}
 125 +
 126 +static inline void setsck(struct spi_device *dev, int val)
 127 +{
 128 +       struct spi_gpio *sp = spidev_to_sg(dev);
 129 +       gpio_set_value(sp->info->pin_clk, val ? 1 : 0);
 130 +}
 131 +
 132 +static inline void setmosi(struct spi_device *dev, int val)
 133 +{
 134 +       struct spi_gpio *sp = spidev_to_sg(dev);
 135 +       gpio_set_value(sp->info->pin_mosi, val ? 1 : 0);
 136 +}
 137 +
 138 +static inline u32 getmiso(struct spi_device *dev)
 139 +{
 140 +       struct spi_gpio *sp = spidev_to_sg(dev);
 141 +       return gpio_get_value(sp->info->pin_miso) ? 1 : 0;
 142 +}
 143 +
 144 +static inline void do_spidelay(struct spi_device *dev, unsigned nsecs)
 145 +{
 146 +       struct spi_gpio *sp = spidev_to_sg(dev);
 147 +
 148 +       if (!sp->info->no_spi_delay)
 149 +               ndelay(nsecs);
 150 +}
 151 +
 152 +#define spidelay(nsecs) do {                                   \
 153 +       /* Steal the spi_device pointer from our caller.        \
 154 +        * The bitbang-API should probably get fixed here... */ \
 155 +       do_spidelay(spi, nsecs);                                \
 156 +  } while (0)
 157 +
 158 +#define EXPAND_BITBANG_TXRX
 159 +#include <linux/spi/spi_bitbang.h>
 160 +
 161 +static u32 spi_gpio_txrx_mode0(struct spi_device *spi,
 162 +                              unsigned nsecs, u32 word, u8 bits)
 163 +{
 164 +       return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
 165 +}
 166 +
 167 +static u32 spi_gpio_txrx_mode1(struct spi_device *spi,
 168 +                              unsigned nsecs, u32 word, u8 bits)
 169 +{
 170 +       return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
 171 +}
 172 +
 173 +static u32 spi_gpio_txrx_mode2(struct spi_device *spi,
 174 +                              unsigned nsecs, u32 word, u8 bits)
 175 +{
 176 +       return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
 177 +}
 178 +
 179 +static u32 spi_gpio_txrx_mode3(struct spi_device *spi,
 180 +                              unsigned nsecs, u32 word, u8 bits)
 181 +{
 182 +       return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
 183 +}
 184 +
 185 +static void spi_gpio_chipselect(struct spi_device *dev, int on)
 186 +{
 187 +       struct spi_gpio *sp = spidev_to_sg(dev);
 188 +
 189 +       if (sp->info->cs_activelow)
 190 +               on = !on;
 191 +       gpio_set_value(sp->info->pin_cs, on ? 1 : 0);
 192 +}
 193 +
 194 +static int spi_gpio_probe(struct platform_device *pdev)
 195 +{
 196 +       struct spi_master *master;
 197 +       struct spi_gpio_platform_data *pdata;
 198 +       struct spi_gpio *sp;
 199 +       struct spi_device *spidev;
 200 +       int err;
 201 +
 202 +       pdata = pdev->dev.platform_data;
 203 +       if (!pdata)
 204 +               return -ENXIO;
 205 +
 206 +       err = -ENOMEM;
 207 +       master = spi_alloc_master(&pdev->dev, sizeof(struct spi_gpio));
 208 +       if (!master)
 209 +               goto err_alloc_master;
 210 +
 211 +       sp = spi_master_get_devdata(master);
 212 +       platform_set_drvdata(pdev, sp);
 213 +       sp->info = pdata;
 214 +
 215 +       err = gpio_request(pdata->pin_clk, "spi_clock");
 216 +       if (err)
 217 +               goto err_request_clk;
 218 +       err = gpio_request(pdata->pin_mosi, "spi_mosi");
 219 +       if (err)
 220 +               goto err_request_mosi;
 221 +       err = gpio_request(pdata->pin_miso, "spi_miso");
 222 +       if (err)
 223 +               goto err_request_miso;
 224 +       err = gpio_request(pdata->pin_cs, "spi_cs");
 225 +       if (err)
 226 +               goto err_request_cs;
 227 +
 228 +       sp->bitbang.master = spi_master_get(master);
 229 +       sp->bitbang.master->bus_num = -1;
 230 +       sp->bitbang.master->num_chipselect = 1;
 231 +       sp->bitbang.chipselect = spi_gpio_chipselect;
 232 +       sp->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_mode0;
 233 +       sp->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_mode1;
 234 +       sp->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_mode2;
 235 +       sp->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_mode3;
 236 +
 237 +       gpio_direction_output(pdata->pin_clk, 0);
 238 +       gpio_direction_output(pdata->pin_mosi, 0);
 239 +       gpio_direction_output(pdata->pin_cs,
 240 +                             pdata->cs_activelow ? 1 : 0);
 241 +       gpio_direction_input(pdata->pin_miso);
 242 +
 243 +       err = spi_bitbang_start(&sp->bitbang);
 244 +       if (err)
 245 +               goto err_no_bitbang;
 246 +       err = pdata->boardinfo_setup(&sp->bi, master,
 247 +                                    pdata->boardinfo_setup_data);
 248 +       if (err)
 249 +               goto err_bi_setup;
 250 +       sp->bi.controller_data = sp;
 251 +       spidev = spi_new_device(master, &sp->bi);
 252 +       if (!spidev)
 253 +               goto err_new_dev;
 254 +
 255 +       return 0;
 256 +
 257 +err_new_dev:
 258 +err_bi_setup:
 259 +       spi_bitbang_stop(&sp->bitbang);
 260 +err_no_bitbang:
 261 +       spi_master_put(sp->bitbang.master);
 262 +       gpio_free(pdata->pin_cs);
 263 +err_request_cs:
 264 +       gpio_free(pdata->pin_miso);
 265 +err_request_miso:
 266 +       gpio_free(pdata->pin_mosi);
 267 +err_request_mosi:
 268 +       gpio_free(pdata->pin_clk);
 269 +err_request_clk:
 270 +       kfree(master);
 271 +
 272 +err_alloc_master:
 273 +       return err;
 274 +}
 275 +
 276 +static int __devexit spi_gpio_remove(struct platform_device *pdev)
 277 +{
 278 +       struct spi_gpio *sp;
 279 +       struct spi_gpio_platform_data *pdata;
 280 +
 281 +       pdata = pdev->dev.platform_data;
 282 +       sp = platform_get_drvdata(pdev);
 283 +
 284 +       gpio_free(pdata->pin_clk);
 285 +       gpio_free(pdata->pin_mosi);
 286 +       gpio_free(pdata->pin_miso);
 287 +       gpio_free(pdata->pin_cs);
 288 +       spi_bitbang_stop(&sp->bitbang);
 289 +       spi_master_put(sp->bitbang.master);
 290 +
 291 +       return 0;
 292 +}
 293 +
 294 +static struct platform_driver spi_gpio_driver = {
 295 +       .driver         = {
 296 +               .name   = SPI_GPIO_PLATDEV_NAME,
 297 +               .owner  = THIS_MODULE,
 298 +       },
 299 +       .probe          = spi_gpio_probe,
 300 +       .remove         = __devexit_p(spi_gpio_remove),
 301 +};
 302 +
 303 +int spi_gpio_next_id(void)
 304 +{
 305 +       static atomic_t counter = ATOMIC_INIT(-1);
 306 +
 307 +       return atomic_inc_return(&counter);
 308 +}
 309 +EXPORT_SYMBOL(spi_gpio_next_id);
 310 +
 311 +static int __init spi_gpio_init(void)
 312 +{
 313 +       int err;
 314 +
 315 +       err = platform_driver_register(&spi_gpio_driver);
 316 +       if (err)
 317 +               printk(KERN_ERR "spi-gpio: register failed: %d\n", err);
 318 +
 319 +       return err;
 320 +}
 321 +module_init(spi_gpio_init);
 322 +
 323 +static void __exit spi_gpio_exit(void)
 324 +{
 325 +       platform_driver_unregister(&spi_gpio_driver);
 326 +}
 327 +module_exit(spi_gpio_exit);
 328 +
 329 +MODULE_AUTHOR("Piot Skamruk <piotr.skamruk at gmail.com>");
 330 +MODULE_DESCRIPTION("Platform independent GPIO bitbanging SPI driver");
 331 +MODULE_LICENSE("GPL v2");
 332 Index: linux-2.6.25.17/drivers/spi/Kconfig
 333 ===================================================================
 334 --- linux-2.6.25.17.orig/drivers/spi/Kconfig    2008-10-18 23:30:41.000000000 +0200
 335 +++ linux-2.6.25.17/drivers/spi/Kconfig 2008-10-18 23:30:43.000000000 +0200
 336 @@ -100,6 +100,19 @@ config SPI_BUTTERFLY
 337           inexpensive battery powered microcontroller evaluation board.
 338           This same cable can be used to flash new firmware.
 339
 340 +config SPI_GPIO
 341 +       tristate "GPIO API based bitbanging SPI controller"
 342 +       depends on SPI_MASTER && GENERIC_GPIO
 343 +       select SPI_BITBANG
 344 +       help
 345 +         This is a platform driver that can be used for bitbanging
 346 +         an SPI bus over GPIO pins.
 347 +         Select this if you have any SPI device that is connected via
 348 +         GPIO pins.
 349 +         The module will be called spi_gpio.
 350 +
 351 +         If unsure, say N.
 352 +
 353  config SPI_IMX
 354         tristate "Freescale iMX SPI controller"
 355         depends on SPI_MASTER && ARCH_IMX && EXPERIMENTAL
 356 Index: linux-2.6.25.17/drivers/spi/Makefile
 357 ===================================================================
 358 --- linux-2.6.25.17.orig/drivers/spi/Makefile   2008-10-18 23:30:41.000000000 +0200
 359 +++ linux-2.6.25.17/drivers/spi/Makefile        2008-10-18 23:30:43.000000000 +0200
 360 @@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_BFIN)                        += spi_bfin5xx.
 361  obj-$(CONFIG_SPI_BITBANG)              += spi_bitbang.o
 362  obj-$(CONFIG_SPI_AU1550)               += au1550_spi.o
 363  obj-$(CONFIG_SPI_BUTTERFLY)            += spi_butterfly.o
 364 +obj-$(CONFIG_SPI_GPIO)                 += spi_gpio.o
 365  obj-$(CONFIG_SPI_IMX)                  += spi_imx.o
 366  obj-$(CONFIG_SPI_LM70_LLP)             += spi_lm70llp.o
 367  obj-$(CONFIG_SPI_PXA2XX)               += pxa2xx_spi.o