Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752945AbZIKBax (ORCPT ); Thu, 10 Sep 2009 21:30:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752035AbZIKBax (ORCPT ); Thu, 10 Sep 2009 21:30:53 -0400 Received: from relay1.sgi.com ([192.48.179.29]:54706 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751929AbZIKBaw (ORCPT ); Thu, 10 Sep 2009 21:30:52 -0400 Date: Thu, 10 Sep 2009 20:30:54 -0500 From: Dimitri Sivanich To: linux-kernel@vger.kernel.org Subject: [PATCH] Add memory mapped RTC driver for UV Message-ID: <20090911013054.GA6567@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7619 Lines: 266 This driver memory maps the UV Hub RTC. Signed-off-by: Dimitri Sivanich --- drivers/char/Kconfig | 8 + drivers/char/Makefile | 1 drivers/char/uv_mmtimer.c | 214 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 223 insertions(+) Index: linux/drivers/char/Kconfig =================================================================== --- linux.orig/drivers/char/Kconfig 2009-09-10 12:38:30.000000000 -0500 +++ linux/drivers/char/Kconfig 2009-09-10 12:40:12.000000000 -0500 @@ -1087,6 +1087,14 @@ config MMTIMER The mmtimer device allows direct userspace access to the Altix system timer. +config UV_MMTIMER + tristate "UV_MMTIMER Memory mapped RTC for SGI UV" + depends on X86_UV + default m + help + The uv_mmtimer device allows direct userspace access to the + UV system timer. + source "drivers/char/tpm/Kconfig" config TELCLOCK Index: linux/drivers/char/Makefile =================================================================== --- linux.orig/drivers/char/Makefile 2009-09-10 12:38:30.000000000 -0500 +++ linux/drivers/char/Makefile 2009-09-10 12:40:12.000000000 -0500 @@ -58,6 +58,7 @@ obj-$(CONFIG_RAW_DRIVER) += raw.o obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o obj-$(CONFIG_MSPEC) += mspec.o obj-$(CONFIG_MMTIMER) += mmtimer.o +obj-$(CONFIG_UV_MMTIMER) += uv_mmtimer.o obj-$(CONFIG_VIOTAPE) += viotape.o obj-$(CONFIG_HVCS) += hvcs.o obj-$(CONFIG_IBM_BSR) += bsr.o Index: linux/drivers/char/uv_mmtimer.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux/drivers/char/uv_mmtimer.c 2009-09-10 14:09:35.000000000 -0500 @@ -0,0 +1,214 @@ +/* + * Timer device implementation for SGI UV platform. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (c) 2009 Silicon Graphics, Inc. All rights reserved. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +MODULE_AUTHOR("Dimitri Sivanich "); +MODULE_DESCRIPTION("SGI UV Memory Mapped RTC Timer"); +MODULE_LICENSE("GPL"); + +/* name of the device, usually in /dev */ +#define UV_MMTIMER_NAME "mmtimer" +#define UV_MMTIMER_DESC "SGI UV Memory Mapped RTC Timer" +#define UV_MMTIMER_VERSION "1.0" + +static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd, + unsigned long arg); +static int uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma); + +/* + * Period in femtoseconds (10^-15 s) + */ +static unsigned long uv_mmtimer_femtoperiod; + +static const struct file_operations uv_mmtimer_fops = { + .owner = THIS_MODULE, + .mmap = uv_mmtimer_mmap, + .unlocked_ioctl = uv_mmtimer_ioctl, +}; + +/** + * uv_mmtimer_ioctl - ioctl interface for /dev/uv_mmtimer + * @file: file structure for the device + * @cmd: command to execute + * @arg: optional argument to command + * + * Executes the command specified by @cmd. Returns 0 for success, < 0 for + * failure. + * + * Valid commands: + * + * %MMTIMER_GETOFFSET - Should return the offset (relative to the start + * of the page where the registers are mapped) for the counter in question. + * + * %MMTIMER_GETRES - Returns the resolution of the clock in femto (10^-15) + * seconds + * + * %MMTIMER_GETFREQ - Copies the frequency of the clock in Hz to the address + * specified by @arg + * + * %MMTIMER_GETBITS - Returns the number of bits in the clock's counter + * + * %MMTIMER_MMAPAVAIL - Returns 1 if registers can be mmap'd into userspace + * + * %MMTIMER_GETCOUNTER - Gets the current value in the counter and places it + * in the address specified by @arg. + */ +static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int ret = 0; + + switch (cmd) { + case MMTIMER_GETOFFSET: /* offset of the counter */ + /* + * UV RTC register is on it's own page + */ + if (PAGE_SIZE <= (1 << 16)) + ret = ((UV_LOCAL_MMR_BASE | UVH_RTC) & (PAGE_SIZE-1)) + / 8; + else + ret = -ENOSYS; + break; + + case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */ + if (copy_to_user((unsigned long __user *)arg, + &uv_mmtimer_femtoperiod, sizeof(unsigned long))) + ret = -EFAULT; + break; + + case MMTIMER_GETFREQ: /* frequency in Hz */ + if (copy_to_user((unsigned long __user *)arg, + &sn_rtc_cycles_per_second, + sizeof(unsigned long))) + ret = -EFAULT; + break; + + case MMTIMER_GETBITS: /* number of bits in the clock */ + ret = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK); + break; + + case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */ + ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0; + break; + + case MMTIMER_GETCOUNTER: + if (copy_to_user((unsigned long __user *)arg, + (unsigned long *)uv_local_mmr_address(UVH_RTC), + sizeof(unsigned long))) + ret = -EFAULT; + break; + default: + ret = -ENOTTY; + break; + } + return ret; +} + +/** + * uv_mmtimer_mmap - maps the clock's registers into userspace + * @file: file structure for the device + * @vma: VMA to map the registers into + * + * Calls remap_pfn_range() to map the clock's registers into + * the calling process' address space. + */ +static int uv_mmtimer_mmap(struct file *file, struct vm_area_struct *vma) +{ + unsigned long uv_mmtimer_addr; + + if (vma->vm_end - vma->vm_start != PAGE_SIZE) + return -EINVAL; + + if (vma->vm_flags & VM_WRITE) + return -EPERM; + + if (PAGE_SIZE > (1 << 16)) + return -ENOSYS; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + + uv_mmtimer_addr = UV_LOCAL_MMR_BASE | UVH_RTC; + uv_mmtimer_addr &= ~(PAGE_SIZE - 1); + uv_mmtimer_addr &= 0xfffffffffffffffUL; + + if (remap_pfn_range(vma, vma->vm_start, uv_mmtimer_addr >> PAGE_SHIFT, + PAGE_SIZE, vma->vm_page_prot)) { + printk(KERN_ERR "remap_pfn_range failed in uv_mmtimer_mmap\n"); + return -EAGAIN; + } + + return 0; +} + +static struct miscdevice uv_mmtimer_miscdev = { + MISC_DYNAMIC_MINOR, + UV_MMTIMER_NAME, + &uv_mmtimer_fops +}; + + +/** + * uv_mmtimer_init - device initialization routine + * + * Does initial setup for the uv_mmtimer device. + */ +static int __init uv_mmtimer_init(void) +{ + if (!is_uv_system()) + return 0; + + /* + * Sanity check the cycles/sec variable + */ + if (sn_rtc_cycles_per_second < 100000) { + printk(KERN_ERR "%s: unable to determine clock frequency\n", + UV_MMTIMER_NAME); + return -1; + } + + uv_mmtimer_femtoperiod = ((unsigned long)1E15 + + sn_rtc_cycles_per_second / 2) / + sn_rtc_cycles_per_second; + + if (misc_register(&uv_mmtimer_miscdev)) { + printk(KERN_ERR "%s: failed to register device\n", + UV_MMTIMER_NAME); + return -1; + } + + printk(KERN_INFO "%s: v%s, %ld MHz\n", UV_MMTIMER_DESC, + UV_MMTIMER_VERSION, + sn_rtc_cycles_per_second/(unsigned long)1E6); + + return 0; +} + +module_init(uv_mmtimer_init); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/