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

   1 Index: linux-2.6.25.10/include/linux/spi/spi_gpio.h
   2 ===================================================================
   3 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
   4 +++ linux-2.6.25.10/include/linux/spi/spi_gpio.h        2008-07-20 20:10:21.000000000 +0200
   5 @@ -0,0 +1,73 @@
   6 +/*
   7 + * spi_gpio interface to platform code
   8 + *
   9 + * Copyright (c) 2008 Piotr Skamruk
  10 + * Copyright (c) 2008 Michael Buesch
  11 + *
  12 + * This program is free software; you can redistribute it and/or modify
  13 + * it under the terms of the GNU General Public License version 2 as
  14 + * published by the Free Software Foundation.
  15 + */
  16 +#ifndef _LINUX_SPI_SPI_GPIO
  17 +#define _LINUX_SPI_SPI_GPIO
  18 +
  19 +#include <linux/types.h>
  20 +#include <linux/spi/spi.h>
  21 +
  22 +
  23 +/**
  24 + * struct spi_gpio_platform_data - Data definitions for a SPI-GPIO device.
  25 + *
  26 + * This structure holds information about a GPIO-based SPI device.
  27 + *
  28 + * @pin_clk: The GPIO pin number of the CLOCK pin.
  29 + *
  30 + * @pin_miso: The GPIO pin number of the MISO pin.
  31 + *
  32 + * @pin_mosi: The GPIO pin number of the MOSI pin.
  33 + *
  34 + * @pin_cs: The GPIO pin number of the CHIPSELECT pin.
  35 + *
  36 + * @cs_activelow: If true, the chip is selected when the CS line is low.
  37 + *
  38 + * @no_spi_delay: If true, no delay is done in the lowlevel bitbanging.
  39 + *                Note that doing no delay is not standards compliant,
  40 + *                but it might be needed to speed up transfers on some
  41 + *                slow embedded machines.
  42 + *
  43 + * @boardinfo_setup: This callback is called after the
  44 + *                   SPI master device was registered, but before the
  45 + *                   device is registered.
  46 + * @boardinfo_setup_data: Data argument passed to boardinfo_setup().
  47 + */
  48 +struct spi_gpio_platform_data {
  49 +       unsigned int pin_clk;
  50 +       unsigned int pin_miso;
  51 +       unsigned int pin_mosi;
  52 +       unsigned int pin_cs;
  53 +       bool cs_activelow;
  54 +       bool no_spi_delay;
  55 +       int (*boardinfo_setup)(struct spi_board_info *bi,
  56 +                              struct spi_master *master,
  57 +                              void *data);
  58 +       void *boardinfo_setup_data;
  59 +};
  60 +
  61 +/**
  62 + * SPI_GPIO_PLATDEV_NAME - The platform device name string.
  63 + *
  64 + * The name string that has to be used for platform_device_alloc
  65 + * when allocating a spi-gpio device.
  66 + */
  67 +#define SPI_GPIO_PLATDEV_NAME  "spi-gpio"
  68 +
  69 +/**
  70 + * spi_gpio_next_id - Get another platform device ID number.
  71 + *
  72 + * This returns the next platform device ID number that has to be used
  73 + * for platform_device_alloc. The ID is opaque and should not be used for
  74 + * anything else.
  75 + */
  76 +int spi_gpio_next_id(void);
  77 +
  78 +#endif /* _LINUX_SPI_SPI_GPIO */
  79 Index: linux-2.6.25.10/drivers/spi/spi_gpio.c
  80 ===================================================================
  81 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  82 +++ linux-2.6.25.10/drivers/spi/spi_gpio.c      2008-07-20 20:10:21.000000000 +0200
  83 @@ -0,0 +1,251 @@
  84 +/*
  85 + * Bitbanging SPI bus driver using GPIO API
  86 + *
  87 + * Copyright (c) 2008 Piotr Skamruk
  88 + * Copyright (c) 2008 Michael Buesch
  89 + *
  90 + * based on spi_s3c2410_gpio.c
  91 + *   Copyright (c) 2006 Ben Dooks
  92 + *   Copyright (c) 2006 Simtec Electronics
  93 + * and on i2c-gpio.c
  94 + *   Copyright (C) 2007 Atmel Corporation
  95 + *
  96 + * This program is free software; you can redistribute it and/or modify
  97 + * it under the terms of the GNU General Public License version 2 as
  98 + * published by the Free Software Foundation.
  99 + */
 100 +
 101 +#include <linux/kernel.h>
 102 +#include <linux/init.h>
 103 +#include <linux/delay.h>
 104 +#include <linux/spinlock.h>
 105 +#include <linux/workqueue.h>
 106 +#include <linux/module.h>
 107 +#include <linux/platform_device.h>
 108 +#include <linux/spi/spi.h>
 109 +#include <linux/spi/spi_bitbang.h>
 110 +#include <linux/spi/spi_gpio.h>
 111 +#include <linux/gpio.h>
 112 +#include <asm/atomic.h>
 113 +
 114 +
 115 +struct spi_gpio {
 116 +       struct spi_bitbang bitbang;
 117 +       struct spi_gpio_platform_data *info;
 118 +       struct platform_device *pdev;
 119 +       struct spi_board_info bi;
 120 +};
 121 +
 122 +
 123 +static inline struct spi_gpio *spidev_to_sg(struct spi_device *dev)
 124 +{
 125 +       return dev->controller_data;
 126 +}
 127 +
 128 +static inline void setsck(struct spi_device *dev, int val)
 129 +{
 130 +       struct spi_gpio *sp = spidev_to_sg(dev);
 131 +       gpio_set_value(sp->info->pin_clk, val ? 1 : 0);
 132 +}
 133 +
 134 +static inline void setmosi(struct spi_device *dev, int val)
 135 +{
 136 +       struct spi_gpio *sp = spidev_to_sg(dev);
 137 +       gpio_set_value(sp->info->pin_mosi, val ? 1 : 0);
 138 +}
 139 +
 140 +static inline u32 getmiso(struct spi_device *dev)
 141 +{
 142 +       struct spi_gpio *sp = spidev_to_sg(dev);
 143 +       return gpio_get_value(sp->info->pin_miso) ? 1 : 0;
 144 +}
 145 +
 146 +static inline void do_spidelay(struct spi_device *dev, unsigned nsecs)
 147 +{
 148 +       struct spi_gpio *sp = spidev_to_sg(dev);
 149 +
 150 +       if (!sp->info->no_spi_delay)
 151 +               ndelay(nsecs);
 152 +}
 153 +
 154 +#define spidelay(nsecs) do {                                   \
 155 +       /* Steal the spi_device pointer from our caller.        \
 156 +        * The bitbang-API should probably get fixed here... */ \
 157 +       do_spidelay(spi, nsecs);                                \
 158 +  } while (0)
 159 +
 160 +#define EXPAND_BITBANG_TXRX
 161 +#include <linux/spi/spi_bitbang.h>
 162 +
 163 +static u32 spi_gpio_txrx_mode0(struct spi_device *spi,
 164 +                              unsigned nsecs, u32 word, u8 bits)
 165 +{
 166 +       return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
 167 +}
 168 +
 169 +static u32 spi_gpio_txrx_mode1(struct spi_device *spi,
 170 +                              unsigned nsecs, u32 word, u8 bits)
 171 +{
 172 +       return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits);
 173 +}
 174 +
 175 +static u32 spi_gpio_txrx_mode2(struct spi_device *spi,
 176 +                              unsigned nsecs, u32 word, u8 bits)
 177 +{
 178 +       return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits);
 179 +}
 180 +
 181 +static u32 spi_gpio_txrx_mode3(struct spi_device *spi,
 182 +                              unsigned nsecs, u32 word, u8 bits)
 183 +{
 184 +       return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits);
 185 +}
 186 +
 187 +static void spi_gpio_chipselect(struct spi_device *dev, int on)
 188 +{
 189 +       struct spi_gpio *sp = spidev_to_sg(dev);
 190 +
 191 +       if (sp->info->cs_activelow)
 192 +               on = !on;
 193 +       gpio_set_value(sp->info->pin_cs, on ? 1 : 0);
 194 +}
 195 +
 196 +static int spi_gpio_probe(struct platform_device *pdev)
 197 +{
 198 +       struct spi_master *master;
 199 +       struct spi_gpio_platform_data *pdata;
 200 +       struct spi_gpio *sp;
 201 +       struct spi_device *spidev;
 202 +       int err;
 203 +
 204 +       pdata = pdev->dev.platform_data;
 205 +       if (!pdata)
 206 +               return -ENXIO;
 207 +
 208 +       err = -ENOMEM;
 209 +       master = spi_alloc_master(&pdev->dev, sizeof(struct spi_gpio));
 210 +       if (!master)
 211 +               goto err_alloc_master;
 212 +
 213 +       sp = spi_master_get_devdata(master);
 214 +       platform_set_drvdata(pdev, sp);
 215 +       sp->info = pdata;
 216 +
 217 +       err = gpio_request(pdata->pin_clk, "spi_clock");
 218 +       if (err)
 219 +               goto err_request_clk;
 220 +       err = gpio_request(pdata->pin_mosi, "spi_mosi");
 221 +       if (err)
 222 +               goto err_request_mosi;
 223 +       err = gpio_request(pdata->pin_miso, "spi_miso");
 224 +       if (err)
 225 +               goto err_request_miso;
 226 +       err = gpio_request(pdata->pin_cs, "spi_cs");
 227 +       if (err)
 228 +               goto err_request_cs;
 229 +
 230 +       sp->bitbang.master = spi_master_get(master);
 231 +       sp->bitbang.master->bus_num = -1;
 232 +       sp->bitbang.master->num_chipselect = 1;
 233 +       sp->bitbang.chipselect = spi_gpio_chipselect;
 234 +       sp->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_mode0;
 235 +       sp->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_mode1;
 236 +       sp->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_mode2;
 237 +       sp->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_mode3;
 238 +
 239 +       gpio_direction_output(pdata->pin_clk, 0);
 240 +       gpio_direction_output(pdata->pin_mosi, 0);
 241 +       gpio_direction_output(pdata->pin_cs,
 242 +                             pdata->cs_activelow ? 1 : 0);
 243 +       gpio_direction_input(pdata->pin_miso);
 244 +
 245 +       err = spi_bitbang_start(&sp->bitbang);
 246 +       if (err)
 247 +               goto err_no_bitbang;
 248 +       err = pdata->boardinfo_setup(&sp->bi, master,
 249 +                                    pdata->boardinfo_setup_data);
 250 +       if (err)
 251 +               goto err_bi_setup;
 252 +       sp->bi.controller_data = sp;
 253 +       spidev = spi_new_device(master, &sp->bi);
 254 +       if (!spidev)
 255 +               goto err_new_dev;
 256 +
 257 +       return 0;
 258 +
 259 +err_new_dev:
 260 +err_bi_setup:
 261 +       spi_bitbang_stop(&sp->bitbang);
 262 +err_no_bitbang:
 263 +       spi_master_put(sp->bitbang.master);
 264 +       gpio_free(pdata->pin_cs);
 265 +err_request_cs:
 266 +       gpio_free(pdata->pin_miso);
 267 +err_request_miso:
 268 +       gpio_free(pdata->pin_mosi);
 269 +err_request_mosi:
 270 +       gpio_free(pdata->pin_clk);
 271 +err_request_clk:
 272 +       kfree(master);
 273 +
 274 +err_alloc_master:
 275 +       return err;
 276 +}
 277 +
 278 +static int __devexit spi_gpio_remove(struct platform_device *pdev)
 279 +{
 280 +       struct spi_gpio *sp;
 281 +       struct spi_gpio_platform_data *pdata;
 282 +
 283 +       pdata = pdev->dev.platform_data;
 284 +       sp = platform_get_drvdata(pdev);
 285 +
 286 +       gpio_free(pdata->pin_clk);
 287 +       gpio_free(pdata->pin_mosi);
 288 +       gpio_free(pdata->pin_miso);
 289 +       gpio_free(pdata->pin_cs);
 290 +       spi_bitbang_stop(&sp->bitbang);
 291 +       spi_master_put(sp->bitbang.master);
 292 +
 293 +       return 0;
 294 +}
 295 +
 296 +static struct platform_driver spi_gpio_driver = {
 297 +       .driver         = {
 298 +               .name   = SPI_GPIO_PLATDEV_NAME,
 299 +               .owner  = THIS_MODULE,
 300 +       },
 301 +       .probe          = spi_gpio_probe,
 302 +       .remove         = __devexit_p(spi_gpio_remove),
 303 +};
 304 +
 305 +int spi_gpio_next_id(void)
 306 +{
 307 +       static atomic_t counter = ATOMIC_INIT(-1);
 308 +
 309 +       return atomic_inc_return(&counter);
 310 +}
 311 +EXPORT_SYMBOL(spi_gpio_next_id);
 312 +
 313 +static int __init spi_gpio_init(void)
 314 +{
 315 +       int err;
 316 +
 317 +       err = platform_driver_register(&spi_gpio_driver);
 318 +       if (err)
 319 +               printk(KERN_ERR "spi-gpio: register failed: %d\n", err);
 320 +
 321 +       return err;
 322 +}
 323 +module_init(spi_gpio_init);
 324 +
 325 +static void __exit spi_gpio_exit(void)
 326 +{
 327 +       platform_driver_unregister(&spi_gpio_driver);
 328 +}
 329 +module_exit(spi_gpio_exit);
 330 +
 331 +MODULE_AUTHOR("Piot Skamruk <piotr.skamruk at gmail.com>");
 332 +MODULE_AUTHOR("Michael Buesch");
 333 +MODULE_DESCRIPTION("Platform independent GPIO bitbanging SPI driver");
 334 +MODULE_LICENSE("GPL v2");
 335 Index: linux-2.6.25.10/drivers/spi/Kconfig
 336 ===================================================================
 337 --- linux-2.6.25.10.orig/drivers/spi/Kconfig    2008-07-20 20:09:48.000000000 +0200
 338 +++ linux-2.6.25.10/drivers/spi/Kconfig 2008-07-20 20:11:48.000000000 +0200
 339 @@ -100,6 +100,19 @@ config SPI_BUTTERFLY
 340           inexpensive battery powered microcontroller evaluation board.
 341           This same cable can be used to flash new firmware.
 342
 343 +config SPI_GPIO
 344 +       tristate "GPIO API based bitbanging SPI controller"
 345 +       depends on SPI_MASTER && GENERIC_GPIO
 346 +       select SPI_BITBANG
 347 +       help
 348 +         This is a platform driver that can be used for bitbanging
 349 +         an SPI bus over GPIO pins.
 350 +         Select this if you have any SPI device that is connected via
 351 +         GPIO pins.
 352 +         The module will be called spi_gpio.
 353 +
 354 +         If unsure, say N.
 355 +
 356  config SPI_IMX
 357         tristate "Freescale iMX SPI controller"
 358         depends on SPI_MASTER && ARCH_IMX && EXPERIMENTAL
 359 Index: linux-2.6.25.10/drivers/spi/Makefile
 360 ===================================================================
 361 --- linux-2.6.25.10.orig/drivers/spi/Makefile   2008-07-20 20:09:48.000000000 +0200
 362 +++ linux-2.6.25.10/drivers/spi/Makefile        2008-07-20 20:10:21.000000000 +0200
 363 @@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_BFIN)                        += spi_bfin5xx.
 364  obj-$(CONFIG_SPI_BITBANG)              += spi_bitbang.o
 365  obj-$(CONFIG_SPI_AU1550)               += au1550_spi.o
 366  obj-$(CONFIG_SPI_BUTTERFLY)            += spi_butterfly.o
 367 +obj-$(CONFIG_SPI_GPIO)                 += spi_gpio.o
 368  obj-$(CONFIG_SPI_IMX)                  += spi_imx.o
 369  obj-$(CONFIG_SPI_LM70_LLP)             += spi_lm70llp.o
 370  obj-$(CONFIG_SPI_PXA2XX)               += pxa2xx_spi.o
 371 Index: linux-2.6.25.10/MAINTAINERS
 372 ===================================================================
 373 --- linux-2.6.25.10.orig/MAINTAINERS    2008-07-20 20:09:48.000000000 +0200
 374 +++ linux-2.6.25.10/MAINTAINERS 2008-07-20 20:10:59.000000000 +0200
 375 @@ -3685,6 +3685,11 @@ M:       dbrownell@users.sourceforge.net
 376  L:     spi-devel-general@lists.sourceforge.net
 377  S:     Maintained
 378
 379 +SPI GPIO MASTER DRIVER
 380 +P:     Michael Buesch
 381 +M:     mb@bu3sch.de
 382 +S:     Maintained
 383 +
 384  STABLE BRANCH:
 385  P:     Greg Kroah-Hartman
 386  M:     greg@kroah.com