time.c 2.7 KB

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  1. /*
  2. * arch/arm/mach-netx/time.c
  3. *
  4. * Copyright (c) 2005 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
  5. *
  6. * This program is free software; you can redistribute it and/or modify
  7. * it under the terms of the GNU General Public License version 2
  8. * as published by the Free Software Foundation.
  9. *
  10. * This program is distributed in the hope that it will be useful,
  11. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13. * GNU General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU General Public License
  16. * along with this program; if not, write to the Free Software
  17. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18. */
  19. #include <linux/init.h>
  20. #include <linux/interrupt.h>
  21. #include <linux/irq.h>
  22. #include <linux/clocksource.h>
  23. #include <asm/hardware.h>
  24. #include <asm/io.h>
  25. #include <asm/mach/time.h>
  26. #include <asm/arch/netx-regs.h>
  27. /*
  28. * IRQ handler for the timer
  29. */
  30. static irqreturn_t
  31. netx_timer_interrupt(int irq, void *dev_id)
  32. {
  33. write_seqlock(&xtime_lock);
  34. timer_tick();
  35. write_sequnlock(&xtime_lock);
  36. /* acknowledge interrupt */
  37. writel(COUNTER_BIT(0), NETX_GPIO_IRQ);
  38. return IRQ_HANDLED;
  39. }
  40. static struct irqaction netx_timer_irq = {
  41. .name = "NetX Timer Tick",
  42. .flags = IRQF_DISABLED | IRQF_TIMER,
  43. .handler = netx_timer_interrupt,
  44. };
  45. cycle_t netx_get_cycles(void)
  46. {
  47. return readl(NETX_GPIO_COUNTER_CURRENT(1));
  48. }
  49. static struct clocksource clocksource_netx = {
  50. .name = "netx_timer",
  51. .rating = 200,
  52. .read = netx_get_cycles,
  53. .mask = CLOCKSOURCE_MASK(32),
  54. .shift = 20,
  55. .flags = CLOCK_SOURCE_IS_CONTINUOUS,
  56. };
  57. /*
  58. * Set up timer interrupt
  59. */
  60. static void __init netx_timer_init(void)
  61. {
  62. /* disable timer initially */
  63. writel(0, NETX_GPIO_COUNTER_CTRL(0));
  64. /* Reset the timer value to zero */
  65. writel(0, NETX_GPIO_COUNTER_CURRENT(0));
  66. writel(LATCH, NETX_GPIO_COUNTER_MAX(0));
  67. /* acknowledge interrupt */
  68. writel(COUNTER_BIT(0), NETX_GPIO_IRQ);
  69. /* Enable the interrupt in the specific timer register and start timer */
  70. writel(COUNTER_BIT(0), NETX_GPIO_IRQ_ENABLE);
  71. writel(NETX_GPIO_COUNTER_CTRL_IRQ_EN | NETX_GPIO_COUNTER_CTRL_RUN,
  72. NETX_GPIO_COUNTER_CTRL(0));
  73. setup_irq(NETX_IRQ_TIMER0, &netx_timer_irq);
  74. /* Setup timer one for clocksource */
  75. writel(0, NETX_GPIO_COUNTER_CTRL(1));
  76. writel(0, NETX_GPIO_COUNTER_CURRENT(1));
  77. writel(0xFFFFFFFF, NETX_GPIO_COUNTER_MAX(1));
  78. writel(NETX_GPIO_COUNTER_CTRL_RUN,
  79. NETX_GPIO_COUNTER_CTRL(1));
  80. clocksource_netx.mult =
  81. clocksource_hz2mult(CLOCK_TICK_RATE, clocksource_netx.shift);
  82. clocksource_register(&clocksource_netx);
  83. }
  84. struct sys_timer netx_timer = {
  85. .init = netx_timer_init,
  86. };