Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757343Ab1DYNZa (ORCPT ); Mon, 25 Apr 2011 09:25:30 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:57972 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754037Ab1DYNZ2 (ORCPT ); Mon, 25 Apr 2011 09:25:28 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:date:message-id:subject; b=rXolpKUoCwHsAMNCUyP1eM104n9FQrN9GVSG4+BZxdUB12AumOsddq94mfyDAkWNGW NUBi+uRzrw2LPL8hgwyuebauSo/heR3COrD1ApvCZWpczGgzP4XS8BTF7UcNURZSWRf5 H1ObR/WV4qZTw1GSqTboInYhnsKceiNrtKWA0= From: Magnus Damm To: linux-kernel@vger.kernel.org Cc: johnstul@us.ibm.com, Magnus Damm , lethal@linux-sh.org, simon@horms.net, linux-sh@vger.kernel.org Date: Mon, 25 Apr 2011 22:32:11 +0900 Message-Id: <20110425133211.3957.30006.sendpatchset@t400s> Subject: [PATCH] clocksource: sh_cmt: __clocksource_updatefreq_hz() update Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2313 Lines: 71 From: Magnus Damm This patch updates the clocksource part of the CMT driver to make use of the __clocksource_updatefreq_hz() function. Without this patch the old code uses clocksource_register() together with a hack that assumes a never changing clock rate (see clk_enable(), clk_get_rate() and clk_disable()). The patch uses clocksource_register_hz() with 1 Hz as initial value, then lets the ->enable() callback update the value with __clocksource_updatefreq_hz() once the struct clk has been enabled and the frequency is stable. Signed-off-by: Magnus Damm --- Thanks to John Stultz for the framework changes and the initial implementation. Tested on the sh7372 Mackerel board with CMT10. drivers/clocksource/sh_cmt.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) --- 0001/drivers/clocksource/sh_cmt.c +++ work/drivers/clocksource/sh_cmt.c 2011-04-25 14:47:06.000000000 +0900 @@ -416,11 +416,15 @@ static cycle_t sh_cmt_clocksource_read(s static int sh_cmt_clocksource_enable(struct clocksource *cs) { + int ret; struct sh_cmt_priv *p = cs_to_sh_cmt(cs); p->total_cycles = 0; - return sh_cmt_start(p, FLAG_CLOCKSOURCE); + ret = sh_cmt_start(p, FLAG_CLOCKSOURCE); + if (!ret) + __clocksource_updatefreq_hz(cs, p->rate); + return ret; } static void sh_cmt_clocksource_disable(struct clocksource *cs) @@ -448,19 +452,10 @@ static int sh_cmt_register_clocksource(s cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8); cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; - /* clk_get_rate() needs an enabled clock */ - clk_enable(p->clk); - p->rate = clk_get_rate(p->clk) / ((p->width == 16) ? 512 : 8); - clk_disable(p->clk); - - /* TODO: calculate good shift from rate and counter bit width */ - cs->shift = 0; - cs->mult = clocksource_hz2mult(p->rate, cs->shift); - dev_info(&p->pdev->dev, "used as clock source\n"); - clocksource_register(cs); - + /* Register with dummy 1 Hz value, gets updated in ->enable() */ + clocksource_register_hz(cs, 1); return 0; } -- 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/