gpio-twl6040.c 3.3 KB

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  1. /*
  2. * Access to GPOs on TWL6040 chip
  3. *
  4. * Copyright (C) 2012 Texas Instruments, Inc.
  5. *
  6. * Authors:
  7. * Sergio Aguirre <saaguirre@ti.com>
  8. * Peter Ujfalusi <peter.ujfalusi@ti.com>
  9. *
  10. * This program is free software; you can redistribute it and/or modify
  11. * it under the terms of the GNU General Public License as published by
  12. * the Free Software Foundation; either version 2 of the License, or
  13. * (at your option) any later version.
  14. *
  15. * This program is distributed in the hope that it will be useful,
  16. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18. * GNU General Public License for more details.
  19. *
  20. * You should have received a copy of the GNU General Public License
  21. * along with this program; if not, write to the Free Software
  22. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23. */
  24. #include <linux/module.h>
  25. #include <linux/init.h>
  26. #include <linux/kthread.h>
  27. #include <linux/irq.h>
  28. #include <linux/gpio.h>
  29. #include <linux/platform_device.h>
  30. #include <linux/of.h>
  31. #include <linux/mfd/twl6040.h>
  32. static struct gpio_chip twl6040gpo_chip;
  33. static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
  34. {
  35. struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
  36. int ret = 0;
  37. ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
  38. if (ret < 0)
  39. return ret;
  40. return (ret >> offset) & 1;
  41. }
  42. static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
  43. int value)
  44. {
  45. /* This only drives GPOs, and can't change direction */
  46. return 0;
  47. }
  48. static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
  49. {
  50. struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
  51. int ret;
  52. u8 gpoctl;
  53. ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
  54. if (ret < 0)
  55. return;
  56. if (value)
  57. gpoctl = ret | (1 << offset);
  58. else
  59. gpoctl = ret & ~(1 << offset);
  60. twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
  61. }
  62. static struct gpio_chip twl6040gpo_chip = {
  63. .label = "twl6040",
  64. .owner = THIS_MODULE,
  65. .get = twl6040gpo_get,
  66. .direction_output = twl6040gpo_direction_out,
  67. .set = twl6040gpo_set,
  68. .can_sleep = true,
  69. };
  70. /*----------------------------------------------------------------------*/
  71. static int gpo_twl6040_probe(struct platform_device *pdev)
  72. {
  73. struct device *twl6040_core_dev = pdev->dev.parent;
  74. struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
  75. int ret;
  76. twl6040gpo_chip.base = -1;
  77. if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
  78. twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
  79. else
  80. twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
  81. twl6040gpo_chip.parent = &pdev->dev;
  82. #ifdef CONFIG_OF_GPIO
  83. twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
  84. #endif
  85. ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
  86. if (ret < 0) {
  87. dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
  88. twl6040gpo_chip.ngpio = 0;
  89. }
  90. return ret;
  91. }
  92. /* Note: this hardware lives inside an I2C-based multi-function device. */
  93. MODULE_ALIAS("platform:twl6040-gpo");
  94. static struct platform_driver gpo_twl6040_driver = {
  95. .driver = {
  96. .name = "twl6040-gpo",
  97. },
  98. .probe = gpo_twl6040_probe,
  99. };
  100. module_platform_driver(gpo_twl6040_driver);
  101. MODULE_AUTHOR("Texas Instruments, Inc.");
  102. MODULE_DESCRIPTION("GPO interface for TWL6040");
  103. MODULE_LICENSE("GPL");