target/linux/brcm2708/patches-4.1/0031-enabling-the-realtime-clock-1-wire-chip-DS1307-and-1.patch

   1 From 9c50f6318fdf116e5abaeb05bffa0b65e48ba259 Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Wed, 8 May 2013 11:46:50 +0100
   4 Subject: [PATCH 031/121] enabling the realtime clock 1-wire chip DS1307 and
   5  1-wire on GPIO4 (as a module)
   6
   7 1-wire: Add support for configuring pin for w1-gpio kernel module
   8 See: https://github.com/raspberrypi/linux/pull/457
   9
  10 Add bitbanging pullups, use them for w1-gpio
  11
  12 Allows parasite power to work, uses module option pullup=1
  13
  14 bcm2708: Ensure 1-wire pullup is disabled by default, and expose as module parameter
  15
  16 Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk>
  17
  18 w1-gpio: Add gpiopin module parameter and correctly free up gpio pull-up pin, if set
  19
  20 Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk>
  21
  22 w1-gpio: Sort out the pullup/parasitic power tangle
  23 ---
  24  arch/arm/mach-bcm2708/bcm2708.c | 29 +++++++++++++++++
  25  arch/arm/mach-bcm2709/bcm2709.c | 29 +++++++++++++++++
  26  drivers/w1/masters/w1-gpio.c    | 69 +++++++++++++++++++++++++++++++++++++----
  27  drivers/w1/w1.h                 |  6 ++++
  28  drivers/w1/w1_int.c             | 14 +++++++++
  29  drivers/w1/w1_io.c              | 18 +++++++++--
  30  include/linux/w1-gpio.h         |  1 +
  31  7 files changed, 157 insertions(+), 9 deletions(-)
  32
  33 --- a/arch/arm/mach-bcm2708/bcm2708.c
  34 +++ b/arch/arm/mach-bcm2708/bcm2708.c
  35 @@ -36,6 +36,7 @@
  36  #include <linux/of_platform.h>
  37  #include <linux/spi/spi.h>
  38  #include <linux/gpio/machine.h>
  39 +#include <linux/w1-gpio.h>
  40
  41  #include <linux/version.h>
  42  #include <linux/clkdev.h>
  43 @@ -77,12 +78,19 @@
  44   */
  45  #define DMA_MASK_BITS_COMMON 32
  46
  47 +// use GPIO 4 for the one-wire GPIO pin, if enabled
  48 +#define W1_GPIO 4
  49 +// ensure one-wire GPIO pullup is disabled by default
  50 +#define W1_PULLUP -1
  51 +
  52  /* command line parameters */
  53  static unsigned boardrev, serial;
  54  static unsigned uart_clock = UART0_CLOCK;
  55  static unsigned disk_led_gpio = 16;
  56  static unsigned disk_led_active_low = 1;
  57  static unsigned reboot_part = 0;
  58 +static unsigned w1_gpio_pin = W1_GPIO;
  59 +static unsigned w1_gpio_pullup = W1_PULLUP;
  60  static bool vc_i2c_override = false;
  61
  62  static unsigned use_dt = 0;
  63 @@ -303,6 +311,20 @@ static struct platform_device bcm2708_dm
  64         .num_resources = ARRAY_SIZE(bcm2708_dmaengine_resources),
  65  };
  66
  67 +#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
  68 +static struct w1_gpio_platform_data w1_gpio_pdata = {
  69 +       .pin = W1_GPIO,
  70 +        .ext_pullup_enable_pin = W1_PULLUP,
  71 +       .is_open_drain = 0,
  72 +};
  73 +
  74 +static struct platform_device w1_device = {
  75 +       .name = "w1-gpio",
  76 +       .id = -1,
  77 +       .dev.platform_data = &w1_gpio_pdata,
  78 +};
  79 +#endif
  80 +
  81  static u64 fb_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON);
  82
  83  static struct platform_device bcm2708_fb_device = {
  84 @@ -729,6 +751,11 @@ void __init bcm2708_init(void)
  85  #ifdef CONFIG_BCM2708_GPIO
  86         bcm_register_device_dt(&bcm2708_gpio_device);
  87  #endif
  88 +#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
  89 +       w1_gpio_pdata.pin = w1_gpio_pin;
  90 +       w1_gpio_pdata.ext_pullup_enable_pin = w1_gpio_pullup;
  91 +       bcm_register_device_dt(&w1_device);
  92 +#endif
  93         bcm_register_device_dt(&bcm2708_fb_device);
  94         bcm_register_device_dt(&bcm2708_usb_device);
  95
  96 @@ -942,5 +969,7 @@ module_param(uart_clock, uint, 0644);
  97  module_param(disk_led_gpio, uint, 0644);
  98  module_param(disk_led_active_low, uint, 0644);
  99  module_param(reboot_part, uint, 0644);
 100 +module_param(w1_gpio_pin, uint, 0644);
 101 +module_param(w1_gpio_pullup, uint, 0644);
 102  module_param(vc_i2c_override, bool, 0644);
 103  MODULE_PARM_DESC(vc_i2c_override, "Allow the use of VC's I2C peripheral.");
 104 --- a/arch/arm/mach-bcm2709/bcm2709.c
 105 +++ b/arch/arm/mach-bcm2709/bcm2709.c
 106 @@ -36,6 +36,7 @@
 107  #include <linux/of_platform.h>
 108  #include <linux/spi/spi.h>
 109  #include <linux/gpio/machine.h>
 110 +#include <linux/w1-gpio.h>
 111
 112  #include <linux/version.h>
 113  #include <linux/clkdev.h>
 114 @@ -79,12 +80,19 @@
 115   */
 116  #define DMA_MASK_BITS_COMMON 32
 117
 118 +// use GPIO 4 for the one-wire GPIO pin, if enabled
 119 +#define W1_GPIO 4
 120 +// ensure one-wire GPIO pullup is disabled by default
 121 +#define W1_PULLUP -1
 122 +
 123  /* command line parameters */
 124  static unsigned boardrev, serial;
 125  static unsigned uart_clock = UART0_CLOCK;
 126  static unsigned disk_led_gpio = 16;
 127  static unsigned disk_led_active_low = 1;
 128  static unsigned reboot_part = 0;
 129 +static unsigned w1_gpio_pin = W1_GPIO;
 130 +static unsigned w1_gpio_pullup = W1_PULLUP;
 131  static bool vc_i2c_override = false;
 132
 133  static unsigned use_dt = 0;
 134 @@ -313,6 +321,20 @@ static struct platform_device bcm2708_dm
 135         .num_resources = ARRAY_SIZE(bcm2708_dmaengine_resources),
 136  };
 137
 138 +#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
 139 +static struct w1_gpio_platform_data w1_gpio_pdata = {
 140 +       .pin = W1_GPIO,
 141 +        .ext_pullup_enable_pin = W1_PULLUP,
 142 +       .is_open_drain = 0,
 143 +};
 144 +
 145 +static struct platform_device w1_device = {
 146 +       .name = "w1-gpio",
 147 +       .id = -1,
 148 +       .dev.platform_data = &w1_gpio_pdata,
 149 +};
 150 +#endif
 151 +
 152  static u64 fb_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON);
 153
 154  static struct platform_device bcm2708_fb_device = {
 155 @@ -749,6 +771,11 @@ void __init bcm2709_init(void)
 156  #ifdef CONFIG_BCM2708_GPIO
 157         bcm_register_device_dt(&bcm2708_gpio_device);
 158  #endif
 159 +#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
 160 +       w1_gpio_pdata.pin = w1_gpio_pin;
 161 +       w1_gpio_pdata.ext_pullup_enable_pin = w1_gpio_pullup;
 162 +       bcm_register_device_dt(&w1_device);
 163 +#endif
 164         bcm_register_device_dt(&bcm2708_fb_device);
 165         bcm_register_device_dt(&bcm2708_usb_device);
 166
 167 @@ -1110,5 +1137,7 @@ module_param(uart_clock, uint, 0644);
 168  module_param(disk_led_gpio, uint, 0644);
 169  module_param(disk_led_active_low, uint, 0644);
 170  module_param(reboot_part, uint, 0644);
 171 +module_param(w1_gpio_pin, uint, 0644);
 172 +module_param(w1_gpio_pullup, uint, 0644);
 173  module_param(vc_i2c_override, bool, 0644);
 174  MODULE_PARM_DESC(vc_i2c_override, "Allow the use of VC's I2C peripheral.");
 175 --- a/drivers/w1/masters/w1-gpio.c
 176 +++ b/drivers/w1/masters/w1-gpio.c
 177 @@ -23,6 +23,19 @@
 178  #include "../w1.h"
 179  #include "../w1_int.h"
 180
 181 +static int w1_gpio_pullup = 0;
 182 +static int w1_gpio_pullup_orig = 0;
 183 +module_param_named(pullup, w1_gpio_pullup, int, 0);
 184 +MODULE_PARM_DESC(pullup, "Enable parasitic power (power on data) mode");
 185 +static int w1_gpio_pullup_pin = -1;
 186 +static int w1_gpio_pullup_pin_orig = -1;
 187 +module_param_named(extpullup, w1_gpio_pullup_pin, int, 0);
 188 +MODULE_PARM_DESC(extpullup, "GPIO external pullup pin number");
 189 +static int w1_gpio_pin = -1;
 190 +static int w1_gpio_pin_orig = -1;
 191 +module_param_named(gpiopin, w1_gpio_pin, int, 0);
 192 +MODULE_PARM_DESC(gpiopin, "GPIO pin number");
 193 +
 194  static u8 w1_gpio_set_pullup(void *data, int delay)
 195  {
 196         struct w1_gpio_platform_data *pdata = data;
 197 @@ -67,6 +80,16 @@ static u8 w1_gpio_read_bit(void *data)
 198         return gpio_get_value(pdata->pin) ? 1 : 0;
 199  }
 200
 201 +static void w1_gpio_bitbang_pullup(void *data, u8 on)
 202 +{
 203 +       struct w1_gpio_platform_data *pdata = data;
 204 +
 205 +       if (on)
 206 +               gpio_direction_output(pdata->pin, 1);
 207 +       else
 208 +               gpio_direction_input(pdata->pin);
 209 +}
 210 +
 211  #if defined(CONFIG_OF)
 212  static const struct of_device_id w1_gpio_dt_ids[] = {
 213         { .compatible = "w1-gpio" },
 214 @@ -80,6 +103,7 @@ static int w1_gpio_probe_dt(struct platf
 215         struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 216         struct device_node *np = pdev->dev.of_node;
 217         int gpio;
 218 +       u32 value;
 219
 220         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 221         if (!pdata)
 222 @@ -88,6 +112,9 @@ static int w1_gpio_probe_dt(struct platf
 223         if (of_get_property(np, "linux,open-drain", NULL))
 224                 pdata->is_open_drain = 1;
 225
 226 +       if (of_property_read_u32(np, "rpi,parasitic-power", &value) == 0)
 227 +           pdata->parasitic_power = (value != 0);
 228 +
 229         gpio = of_get_gpio(np, 0);
 230         if (gpio < 0) {
 231                 if (gpio != -EPROBE_DEFER)
 232 @@ -103,7 +130,7 @@ static int w1_gpio_probe_dt(struct platf
 233         if (gpio == -EPROBE_DEFER)
 234                 return gpio;
 235         /* ignore other errors as the pullup gpio is optional */
 236 -       pdata->ext_pullup_enable_pin = gpio;
 237 +       pdata->ext_pullup_enable_pin = (gpio >= 0) ? gpio : -1;
 238
 239         pdev->dev.platform_data = pdata;
 240
 241 @@ -113,13 +140,15 @@ static int w1_gpio_probe_dt(struct platf
 242  static int w1_gpio_probe(struct platform_device *pdev)
 243  {
 244         struct w1_bus_master *master;
 245 -       struct w1_gpio_platform_data *pdata;
 246 +       struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
 247         int err;
 248
 249 -       if (of_have_populated_dt()) {
 250 -               err = w1_gpio_probe_dt(pdev);
 251 -               if (err < 0)
 252 -                       return err;
 253 +       if(pdata == NULL) {
 254 +               if (of_have_populated_dt()) {
 255 +                       err = w1_gpio_probe_dt(pdev);
 256 +                       if (err < 0)
 257 +                               return err;
 258 +               }
 259         }
 260
 261         pdata = dev_get_platdata(&pdev->dev);
 262 @@ -136,6 +165,22 @@ static int w1_gpio_probe(struct platform
 263                 return -ENOMEM;
 264         }
 265
 266 +       w1_gpio_pin_orig = pdata->pin;
 267 +       w1_gpio_pullup_pin_orig = pdata->ext_pullup_enable_pin;
 268 +       w1_gpio_pullup_orig = pdata->parasitic_power;
 269 +
 270 +       if(gpio_is_valid(w1_gpio_pin)) {
 271 +               pdata->pin = w1_gpio_pin;
 272 +               pdata->ext_pullup_enable_pin = -1;
 273 +               pdata->parasitic_power = -1;
 274 +       }
 275 +       pdata->parasitic_power |= w1_gpio_pullup;
 276 +       if(gpio_is_valid(w1_gpio_pullup_pin)) {
 277 +               pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin;
 278 +       }
 279 +
 280 +       dev_info(&pdev->dev, "gpio pin %d, external pullup pin %d, parasitic power %d\n", pdata->pin, pdata->ext_pullup_enable_pin, pdata->parasitic_power);
 281 +
 282         err = devm_gpio_request(&pdev->dev, pdata->pin, "w1");
 283         if (err) {
 284                 dev_err(&pdev->dev, "gpio_request (pin) failed\n");
 285 @@ -165,6 +210,14 @@ static int w1_gpio_probe(struct platform
 286                 master->set_pullup = w1_gpio_set_pullup;
 287         }
 288
 289 +       if (pdata->parasitic_power) {
 290 +               if (pdata->is_open_drain)
 291 +                       printk(KERN_ERR "w1-gpio 'pullup'(parasitic power) "
 292 +                              "option doesn't work with open drain GPIO\n");
 293 +               else
 294 +                       master->bitbang_pullup = w1_gpio_bitbang_pullup;
 295 +       }
 296 +
 297         err = w1_add_master_device(master);
 298         if (err) {
 299                 dev_err(&pdev->dev, "w1_add_master device failed\n");
 300 @@ -195,6 +248,10 @@ static int w1_gpio_remove(struct platfor
 301
 302         w1_remove_master_device(master);
 303
 304 +       pdata->pin = w1_gpio_pin_orig;
 305 +       pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin_orig;
 306 +       pdata->parasitic_power = w1_gpio_pullup_orig;
 307 +
 308         return 0;
 309  }
 310
 311 --- a/drivers/w1/w1.h
 312 +++ b/drivers/w1/w1.h
 313 @@ -171,6 +171,12 @@ struct w1_bus_master
 314
 315         u8              (*set_pullup)(void *, int);
 316
 317 +       /**
 318 +        * Turns the pullup on/off in bitbanging mode, takes an on/off argument.
 319 +        * @return -1=Error, 0=completed
 320 +        */
 321 +       void (*bitbang_pullup) (void *, u8);
 322 +
 323         void            (*search)(void *, struct w1_master *,
 324                 u8, w1_slave_found_callback);
 325  };
 326 --- a/drivers/w1/w1_int.c
 327 +++ b/drivers/w1/w1_int.c
 328 @@ -123,6 +123,20 @@ int w1_add_master_device(struct w1_bus_m
 329                 return(-EINVAL);
 330         }
 331
 332 +       /* bitbanging hardware uses bitbang_pullup, other hardware uses set_pullup
 333 +        * and takes care of timing itself */
 334 +       if (!master->write_byte && !master->touch_bit && master->set_pullup) {
 335 +               printk(KERN_ERR "w1_add_master_device: set_pullup requires "
 336 +                       "write_byte or touch_bit, disabling\n");
 337 +               master->set_pullup = NULL;
 338 +       }
 339 +
 340 +       if (master->set_pullup && master->bitbang_pullup) {
 341 +               printk(KERN_ERR "w1_add_master_device: set_pullup should not "
 342 +                      "be set when bitbang_pullup is used, disabling\n");
 343 +               master->set_pullup = NULL;
 344 +       }
 345 +
 346         /* Lock until the device is added (or not) to w1_masters. */
 347         mutex_lock(&w1_mlock);
 348         /* Search for the first available id (starting at 1). */
 349 --- a/drivers/w1/w1_io.c
 350 +++ b/drivers/w1/w1_io.c
 351 @@ -134,10 +134,22 @@ static void w1_pre_write(struct w1_maste
 352  static void w1_post_write(struct w1_master *dev)
 353  {
 354         if (dev->pullup_duration) {
 355 -               if (dev->enable_pullup && dev->bus_master->set_pullup)
 356 -                       dev->bus_master->set_pullup(dev->bus_master->data, 0);
 357 -               else
 358 +               if (dev->enable_pullup) {
 359 +                       if (dev->bus_master->set_pullup) {
 360 +                               dev->bus_master->set_pullup(dev->
 361 +                                                           bus_master->data,
 362 +                                                           0);
 363 +                       } else if (dev->bus_master->bitbang_pullup) {
 364 +                               dev->bus_master->
 365 +                                   bitbang_pullup(dev->bus_master->data, 1);
 366                         msleep(dev->pullup_duration);
 367 +                               dev->bus_master->
 368 +                                   bitbang_pullup(dev->bus_master->data, 0);
 369 +                       }
 370 +               } else {
 371 +                       msleep(dev->pullup_duration);
 372 +               }
 373 +
 374                 dev->pullup_duration = 0;
 375         }
 376  }
 377 --- a/include/linux/w1-gpio.h
 378 +++ b/include/linux/w1-gpio.h
 379 @@ -18,6 +18,7 @@
 380  struct w1_gpio_platform_data {
 381         unsigned int pin;
 382         unsigned int is_open_drain:1;
 383 +       unsigned int parasitic_power:1;
 384         void (*enable_external_pullup)(int enable);
 385         unsigned int ext_pullup_enable_pin;
 386         unsigned int pullup_duration;