ambakmi.c 4.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * linux/drivers/input/serio/ambakmi.c
  4. *
  5. * Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
  6. * Copyright (C) 2002 Russell King.
  7. */
  8. #include <linux/module.h>
  9. #include <linux/serio.h>
  10. #include <linux/errno.h>
  11. #include <linux/interrupt.h>
  12. #include <linux/ioport.h>
  13. #include <linux/device.h>
  14. #include <linux/delay.h>
  15. #include <linux/slab.h>
  16. #include <linux/err.h>
  17. #include <linux/amba/bus.h>
  18. #include <linux/amba/kmi.h>
  19. #include <linux/clk.h>
  20. #include <asm/io.h>
  21. #include <asm/irq.h>
  22. #define KMI_BASE (kmi->base)
  23. struct amba_kmi_port {
  24. struct serio *io;
  25. struct clk *clk;
  26. void __iomem *base;
  27. unsigned int irq;
  28. unsigned int divisor;
  29. unsigned int open;
  30. };
  31. static irqreturn_t amba_kmi_int(int irq, void *dev_id)
  32. {
  33. struct amba_kmi_port *kmi = dev_id;
  34. unsigned int status = readb(KMIIR);
  35. int handled = IRQ_NONE;
  36. while (status & KMIIR_RXINTR) {
  37. serio_interrupt(kmi->io, readb(KMIDATA), 0);
  38. status = readb(KMIIR);
  39. handled = IRQ_HANDLED;
  40. }
  41. return handled;
  42. }
  43. static int amba_kmi_write(struct serio *io, unsigned char val)
  44. {
  45. struct amba_kmi_port *kmi = io->port_data;
  46. unsigned int timeleft = 10000; /* timeout in 100ms */
  47. while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
  48. udelay(10);
  49. if (timeleft)
  50. writeb(val, KMIDATA);
  51. return timeleft ? 0 : SERIO_TIMEOUT;
  52. }
  53. static int amba_kmi_open(struct serio *io)
  54. {
  55. struct amba_kmi_port *kmi = io->port_data;
  56. unsigned int divisor;
  57. int ret;
  58. ret = clk_prepare_enable(kmi->clk);
  59. if (ret)
  60. goto out;
  61. divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
  62. writeb(divisor, KMICLKDIV);
  63. writeb(KMICR_EN, KMICR);
  64. ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050",
  65. kmi);
  66. if (ret) {
  67. printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
  68. writeb(0, KMICR);
  69. goto clk_disable;
  70. }
  71. writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
  72. return 0;
  73. clk_disable:
  74. clk_disable_unprepare(kmi->clk);
  75. out:
  76. return ret;
  77. }
  78. static void amba_kmi_close(struct serio *io)
  79. {
  80. struct amba_kmi_port *kmi = io->port_data;
  81. writeb(0, KMICR);
  82. free_irq(kmi->irq, kmi);
  83. clk_disable_unprepare(kmi->clk);
  84. }
  85. static int amba_kmi_probe(struct amba_device *dev,
  86. const struct amba_id *id)
  87. {
  88. struct amba_kmi_port *kmi;
  89. struct serio *io;
  90. int ret;
  91. ret = amba_request_regions(dev, NULL);
  92. if (ret)
  93. return ret;
  94. kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
  95. io = kzalloc(sizeof(struct serio), GFP_KERNEL);
  96. if (!kmi || !io) {
  97. ret = -ENOMEM;
  98. goto out;
  99. }
  100. io->id.type = SERIO_8042;
  101. io->write = amba_kmi_write;
  102. io->open = amba_kmi_open;
  103. io->close = amba_kmi_close;
  104. strlcpy(io->name, dev_name(&dev->dev), sizeof(io->name));
  105. strlcpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
  106. io->port_data = kmi;
  107. io->dev.parent = &dev->dev;
  108. kmi->io = io;
  109. kmi->base = ioremap(dev->res.start, resource_size(&dev->res));
  110. if (!kmi->base) {
  111. ret = -ENOMEM;
  112. goto out;
  113. }
  114. kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
  115. if (IS_ERR(kmi->clk)) {
  116. ret = PTR_ERR(kmi->clk);
  117. goto unmap;
  118. }
  119. kmi->irq = dev->irq[0];
  120. amba_set_drvdata(dev, kmi);
  121. serio_register_port(kmi->io);
  122. return 0;
  123. unmap:
  124. iounmap(kmi->base);
  125. out:
  126. kfree(kmi);
  127. kfree(io);
  128. amba_release_regions(dev);
  129. return ret;
  130. }
  131. static void amba_kmi_remove(struct amba_device *dev)
  132. {
  133. struct amba_kmi_port *kmi = amba_get_drvdata(dev);
  134. serio_unregister_port(kmi->io);
  135. clk_put(kmi->clk);
  136. iounmap(kmi->base);
  137. kfree(kmi);
  138. amba_release_regions(dev);
  139. }
  140. static int __maybe_unused amba_kmi_resume(struct device *dev)
  141. {
  142. struct amba_kmi_port *kmi = dev_get_drvdata(dev);
  143. /* kick the serio layer to rescan this port */
  144. serio_reconnect(kmi->io);
  145. return 0;
  146. }
  147. static SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume);
  148. static const struct amba_id amba_kmi_idtable[] = {
  149. {
  150. .id = 0x00041050,
  151. .mask = 0x000fffff,
  152. },
  153. { 0, 0 }
  154. };
  155. MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);
  156. static struct amba_driver ambakmi_driver = {
  157. .drv = {
  158. .name = "kmi-pl050",
  159. .owner = THIS_MODULE,
  160. .pm = &amba_kmi_dev_pm_ops,
  161. },
  162. .id_table = amba_kmi_idtable,
  163. .probe = amba_kmi_probe,
  164. .remove = amba_kmi_remove,
  165. };
  166. module_amba_driver(ambakmi_driver);
  167. MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
  168. MODULE_DESCRIPTION("AMBA KMI controller driver");
  169. MODULE_LICENSE("GPL");