pxa930_trkball.c 6.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * PXA930 track ball mouse driver
  4. *
  5. * Copyright (C) 2007 Marvell International Ltd.
  6. * 2008-02-28: Yong Yao <yaoyong@marvell.com>
  7. * initial version
  8. */
  9. #include <linux/input.h>
  10. #include <linux/interrupt.h>
  11. #include <linux/module.h>
  12. #include <linux/platform_device.h>
  13. #include <linux/delay.h>
  14. #include <linux/io.h>
  15. #include <linux/slab.h>
  16. #include <mach/hardware.h>
  17. #include <linux/platform_data/mouse-pxa930_trkball.h>
  18. /* Trackball Controller Register Definitions */
  19. #define TBCR (0x000C)
  20. #define TBCNTR (0x0010)
  21. #define TBSBC (0x0014)
  22. #define TBCR_TBRST (1 << 1)
  23. #define TBCR_TBSB (1 << 10)
  24. #define TBCR_Y_FLT(n) (((n) & 0xf) << 6)
  25. #define TBCR_X_FLT(n) (((n) & 0xf) << 2)
  26. #define TBCNTR_YM(n) (((n) >> 24) & 0xff)
  27. #define TBCNTR_YP(n) (((n) >> 16) & 0xff)
  28. #define TBCNTR_XM(n) (((n) >> 8) & 0xff)
  29. #define TBCNTR_XP(n) ((n) & 0xff)
  30. #define TBSBC_TBSBC (0x1)
  31. struct pxa930_trkball {
  32. struct pxa930_trkball_platform_data *pdata;
  33. /* Memory Mapped Register */
  34. struct resource *mem;
  35. void __iomem *mmio_base;
  36. struct input_dev *input;
  37. };
  38. static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
  39. {
  40. struct pxa930_trkball *trkball = dev_id;
  41. struct input_dev *input = trkball->input;
  42. int tbcntr, x, y;
  43. /* According to the spec software must read TBCNTR twice:
  44. * if the read value is the same, the reading is valid
  45. */
  46. tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);
  47. if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
  48. x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
  49. y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;
  50. input_report_rel(input, REL_X, x);
  51. input_report_rel(input, REL_Y, y);
  52. input_sync(input);
  53. }
  54. __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
  55. __raw_writel(0, trkball->mmio_base + TBSBC);
  56. return IRQ_HANDLED;
  57. }
  58. /* For TBCR, we need to wait for a while to make sure it has been modified. */
  59. static int write_tbcr(struct pxa930_trkball *trkball, int v)
  60. {
  61. int i = 100;
  62. __raw_writel(v, trkball->mmio_base + TBCR);
  63. while (--i) {
  64. if (__raw_readl(trkball->mmio_base + TBCR) == v)
  65. break;
  66. msleep(1);
  67. }
  68. if (i == 0) {
  69. pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
  70. return -ETIMEDOUT;
  71. }
  72. return 0;
  73. }
  74. static void pxa930_trkball_config(struct pxa930_trkball *trkball)
  75. {
  76. uint32_t tbcr;
  77. /* According to spec, need to write the filters of x,y to 0xf first! */
  78. tbcr = __raw_readl(trkball->mmio_base + TBCR);
  79. write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
  80. write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
  81. TBCR_Y_FLT(trkball->pdata->y_filter));
  82. /* According to spec, set TBCR_TBRST first, before clearing it! */
  83. tbcr = __raw_readl(trkball->mmio_base + TBCR);
  84. write_tbcr(trkball, tbcr | TBCR_TBRST);
  85. write_tbcr(trkball, tbcr & ~TBCR_TBRST);
  86. __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
  87. __raw_writel(0, trkball->mmio_base + TBSBC);
  88. pr_debug("%s: final TBCR=%x!\n", __func__,
  89. __raw_readl(trkball->mmio_base + TBCR));
  90. }
  91. static int pxa930_trkball_open(struct input_dev *dev)
  92. {
  93. struct pxa930_trkball *trkball = input_get_drvdata(dev);
  94. pxa930_trkball_config(trkball);
  95. return 0;
  96. }
  97. static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
  98. {
  99. uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);
  100. /* Held in reset, gate the 32-KHz input clock off */
  101. write_tbcr(trkball, tbcr | TBCR_TBRST);
  102. }
  103. static void pxa930_trkball_close(struct input_dev *dev)
  104. {
  105. struct pxa930_trkball *trkball = input_get_drvdata(dev);
  106. pxa930_trkball_disable(trkball);
  107. }
  108. static int pxa930_trkball_probe(struct platform_device *pdev)
  109. {
  110. struct pxa930_trkball *trkball;
  111. struct input_dev *input;
  112. struct resource *res;
  113. int irq, error;
  114. irq = platform_get_irq(pdev, 0);
  115. if (irq < 0)
  116. return -ENXIO;
  117. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  118. if (!res) {
  119. dev_err(&pdev->dev, "failed to get register memory\n");
  120. return -ENXIO;
  121. }
  122. trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
  123. if (!trkball)
  124. return -ENOMEM;
  125. trkball->pdata = dev_get_platdata(&pdev->dev);
  126. if (!trkball->pdata) {
  127. dev_err(&pdev->dev, "no platform data defined\n");
  128. error = -EINVAL;
  129. goto failed;
  130. }
  131. trkball->mmio_base = ioremap(res->start, resource_size(res));
  132. if (!trkball->mmio_base) {
  133. dev_err(&pdev->dev, "failed to ioremap registers\n");
  134. error = -ENXIO;
  135. goto failed;
  136. }
  137. /* held the module in reset, will be enabled in open() */
  138. pxa930_trkball_disable(trkball);
  139. error = request_irq(irq, pxa930_trkball_interrupt, 0,
  140. pdev->name, trkball);
  141. if (error) {
  142. dev_err(&pdev->dev, "failed to request irq: %d\n", error);
  143. goto failed_free_io;
  144. }
  145. platform_set_drvdata(pdev, trkball);
  146. input = input_allocate_device();
  147. if (!input) {
  148. dev_err(&pdev->dev, "failed to allocate input device\n");
  149. error = -ENOMEM;
  150. goto failed_free_irq;
  151. }
  152. input->name = pdev->name;
  153. input->id.bustype = BUS_HOST;
  154. input->open = pxa930_trkball_open;
  155. input->close = pxa930_trkball_close;
  156. input->dev.parent = &pdev->dev;
  157. input_set_drvdata(input, trkball);
  158. trkball->input = input;
  159. input_set_capability(input, EV_REL, REL_X);
  160. input_set_capability(input, EV_REL, REL_Y);
  161. error = input_register_device(input);
  162. if (error) {
  163. dev_err(&pdev->dev, "unable to register input device\n");
  164. goto failed_free_input;
  165. }
  166. return 0;
  167. failed_free_input:
  168. input_free_device(input);
  169. failed_free_irq:
  170. free_irq(irq, trkball);
  171. failed_free_io:
  172. iounmap(trkball->mmio_base);
  173. failed:
  174. kfree(trkball);
  175. return error;
  176. }
  177. static int pxa930_trkball_remove(struct platform_device *pdev)
  178. {
  179. struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
  180. int irq = platform_get_irq(pdev, 0);
  181. input_unregister_device(trkball->input);
  182. free_irq(irq, trkball);
  183. iounmap(trkball->mmio_base);
  184. kfree(trkball);
  185. return 0;
  186. }
  187. static struct platform_driver pxa930_trkball_driver = {
  188. .driver = {
  189. .name = "pxa930-trkball",
  190. },
  191. .probe = pxa930_trkball_probe,
  192. .remove = pxa930_trkball_remove,
  193. };
  194. module_platform_driver(pxa930_trkball_driver);
  195. MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
  196. MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
  197. MODULE_LICENSE("GPL");