Date: Wed, 2 Apr 2014 18:43:56 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r264050 - in head/sys/arm: arm ti/omap4 Message-ID: <201404021843.s32IhuXE017563@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: ian Date: Wed Apr 2 18:43:56 2014 New Revision: 264050 URL: http://svnweb.freebsd.org/changeset/base/264050 Log: Added: head/sys/arm/arm/mpcore_timervar.h (contents, props changed) Modified: head/sys/arm/arm/mpcore_timer.c head/sys/arm/ti/omap4/omap4_prcm_clks.c Modified: head/sys/arm/arm/mpcore_timer.c ============================================================================== --- head/sys/arm/arm/mpcore_timer.c Wed Apr 2 18:32:27 2014 (r264049) +++ head/sys/arm/arm/mpcore_timer.c Wed Apr 2 18:43:56 2014 (r264050) @@ -67,6 +67,8 @@ __FBSDID("$FreeBSD$"); #include <machine/bus.h> #include <machine/fdt.h> +#include <arm/arm/mpcore_timervar.h> + /* Private (per-CPU) timer register map */ #define PRV_TIMER_LOAD 0x0000 #define PRV_TIMER_COUNT 0x0004 @@ -100,7 +102,7 @@ struct arm_tmr_softc { bus_space_tag_t gbl_bst; bus_space_handle_t prv_bsh; bus_space_handle_t gbl_bsh; - uint32_t clkfreq; + uint64_t clkfreq; struct eventtimer et; }; @@ -114,7 +116,7 @@ static struct resource_spec arm_tmr_spec static struct arm_tmr_softc *arm_tmr_sc = NULL; -uint32_t platform_arm_tmr_freq = 0; +static uint64_t platform_arm_tmr_freq = 0; #define tmr_prv_read_4(reg) \ bus_space_read_4(arm_tmr_sc->prv_bst, arm_tmr_sc->prv_bsh, reg) @@ -209,6 +211,7 @@ static int arm_tmr_stop(struct eventtimer *et) { tmr_prv_write_4(PRV_TIMER_CTRL, 0); + tmr_prv_write_4(PRV_TIMER_INTR, PRV_TIMER_INTR_EVENT); return (0); } @@ -278,24 +281,29 @@ arm_tmr_attach(device_t dev) phandle_t node; pcell_t clock; void *ihl; + boolean_t fixed_freq; if (arm_tmr_sc) return (ENXIO); - if (platform_arm_tmr_freq != 0) - sc->clkfreq = platform_arm_tmr_freq; - else { - /* Get the base clock frequency */ - node = ofw_bus_get_node(dev); - if ((OF_getprop(node, "clock-frequency", &clock, - sizeof(clock))) <= 0) { - device_printf(dev, "missing clock-frequency attribute in FDT\n"); - return (ENXIO); + if (platform_arm_tmr_freq == ARM_TMR_FREQUENCY_VARIES) { + fixed_freq = false; + } else { + fixed_freq = true; + if (platform_arm_tmr_freq != 0) { + sc->clkfreq = platform_arm_tmr_freq; + } else { + /* Get the base clock frequency */ + node = ofw_bus_get_node(dev); + if ((OF_getencprop(node, "clock-frequency", &clock, + sizeof(clock))) <= 0) { + device_printf(dev, "missing clock-frequency " + "attribute in FDT\n"); + return (ENXIO); + } } - sc->clkfreq = fdt32_to_cpu(clock); } - if (bus_alloc_resources(dev, arm_tmr_spec, sc->tmr_res)) { device_printf(dev, "could not allocate resources\n"); return (ENXIO); @@ -315,14 +323,6 @@ arm_tmr_attach(device_t dev) tmr_prv_write_4(PRV_TIMER_CTRL, 0x00000000); tmr_gbl_write_4(GBL_TIMER_CTRL, 0x00000000); - /* Setup and enable the global timer to use as the timecounter */ - tmr_gbl_write_4(GBL_TIMER_CTRL, (0x00 << GBL_TIMER_CTR_PRESCALER_SHIFT) | - GBL_TIMER_CTRL_TIMER_ENABLE); - - arm_tmr_timecount.tc_frequency = sc->clkfreq; - tc_init(&arm_tmr_timecount); - - /* Setup and enable the timer */ if (bus_setup_intr(dev, sc->tmr_res[3], INTR_TYPE_CLK, arm_tmr_intr, NULL, sc, &ihl) != 0) { bus_release_resources(dev, arm_tmr_spec, sc->tmr_res); @@ -330,13 +330,35 @@ arm_tmr_attach(device_t dev) return (ENXIO); } + /* + * If the clock is fixed-frequency, setup and enable the global timer to + * use as the timecounter. If it's variable frequency it won't work as + * a timecounter. We also can't use it for DELAY(), so hopefully the + * platform provides its own implementation. If it doesn't, ours will + * get used, but since the frequency isn't set, it will only use the + * bogus loop counter. + */ + if (fixed_freq) { + tmr_gbl_write_4(GBL_TIMER_CTRL, GBL_TIMER_CTRL_TIMER_ENABLE); + arm_tmr_timecount.tc_frequency = sc->clkfreq; + tc_init(&arm_tmr_timecount); + } + + /* + * Setup and register the eventtimer. Most event timers set their min + * and max period values to some value calculated from the clock + * frequency. We might not know yet what our runtime clock frequency + * will be, so we just use some safe values. A max of 2 seconds ensures + * that even if our base clock frequency is 2GHz (meaning a 4GHz CPU), + * we won't overflow our 32-bit timer count register. A min of 20 + * nanoseconds is pretty much completely arbitrary. + */ sc->et.et_name = "MPCore"; sc->et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT | ET_FLAGS_PERCPU; sc->et.et_quality = 1000; - sc->et.et_frequency = sc->clkfreq; - sc->et.et_min_period = (0x00000002LLU << 32) / sc->et.et_frequency; - sc->et.et_max_period = (0xfffffffeLLU << 32) / sc->et.et_frequency; + sc->et.et_min_period = 20 * SBT_1NS; + sc->et.et_max_period = 2 * SBT_1S; sc->et.et_start = arm_tmr_start; sc->et.et_stop = arm_tmr_stop; sc->et.et_priv = sc; @@ -361,6 +383,31 @@ static devclass_t arm_tmr_devclass; DRIVER_MODULE(mp_tmr, simplebus, arm_tmr_driver, arm_tmr_devclass, 0, 0); +/* + * Handle a change in clock frequency. The mpcore timer runs at half the CPU + * frequency. When the CPU frequency changes due to power-saving or thermal + * managment, the platform-specific code that causes the frequency change calls + * this routine to inform the clock driver, and we in turn inform the event + * timer system, which actually updates the value in et->frequency for us and + * reschedules the current event(s) in a way that's atomic with respect to + * start/stop/intr code that may be running on various CPUs at the time of the + * call. + * + * This routine can also be called by a platform's early init code. If the + * value passed is ARM_TMR_FREQUENCY_VARIES, that will cause the attach() code + * to register as an eventtimer, but not a timecounter. If the value passed in + * is any other non-zero value it is used as the fixed frequency for the timer. + */ +void +arm_tmr_change_frequency(uint64_t newfreq) +{ + + if (arm_tmr_sc == NULL) + platform_arm_tmr_freq = newfreq; + else + et_change_frequency(&arm_tmr_sc->et, newfreq); +} + /** * DELAY - Delay for at least usec microseconds. * @usec: number of microseconds to delay by @@ -380,7 +427,7 @@ arm_tmr_DELAY(int usec) uint32_t first, last; /* Check the timers are setup, if not just use a for loop for the meantime */ - if (arm_tmr_sc == NULL) { + if (arm_tmr_sc == NULL || arm_tmr_timecount.tc_frequency == 0) { for (; usec > 0; usec--) for (counts = 200; counts > 0; counts--) cpufunc_nullop(); /* Prevent gcc from optimizing Added: head/sys/arm/arm/mpcore_timervar.h ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/arm/arm/mpcore_timervar.h Wed Apr 2 18:43:56 2014 (r264050) @@ -0,0 +1,47 @@ +/*- + * Copyright (c) 2014 Ian Lepore <ian@freebsd.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#ifndef _ARM_MPCORE_TIMERVAR_H_ +#define _ARM_MPCORE_TIMERVAR_H_ + +/* + * This value, passed to arm_tmr_change_frequency() any time before the mpcore + * timer device attaches, informs the driver that the mpcore clock frequency can + * change on the fly, and thus can't be used as a timecounter. The hardware can + * still be used as an eventtimer, as long as each frequency change is + * communicated to it with calls to arm_tmr_change_frequency(). + */ +#define ARM_TMR_FREQUENCY_VARIES -1ULL + +/* + * Inform the mpcore timer driver of a new clock frequency. This can be called + * both before and after the mpcore timer driver attaches. + */ +void arm_tmr_change_frequency(uint64_t newfreq); + +#endif Modified: head/sys/arm/ti/omap4/omap4_prcm_clks.c ============================================================================== --- head/sys/arm/ti/omap4/omap4_prcm_clks.c Wed Apr 2 18:32:27 2014 (r264049) +++ head/sys/arm/ti/omap4/omap4_prcm_clks.c Wed Apr 2 18:43:56 2014 (r264050) @@ -46,6 +46,7 @@ __FBSDID("$FreeBSD$"); #include <machine/resource.h> #include <machine/intr.h> +#include <arm/arm/mpcore_timervar.h> #include <arm/ti/tivar.h> #include <arm/ti/ti_prcm.h> #include <arm/ti/omap4/omap4_reg.h> @@ -1404,7 +1405,7 @@ omap4_prcm_attach(device_t dev) omap4_prcm_sc = sc; ti_cpu_reset = omap4_prcm_reset; omap4_clk_get_arm_fclk_freq(NULL, &freq); - platform_arm_tmr_freq = freq / 2; + arm_tmr_change_frequency(freq / 2); return (0); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201404021843.s32IhuXE017563>