From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/8] ARM: tegra: config the polarity of the request of sys clock
Date: Mon, 29 Jul 2013 16:47:37 -0600 [thread overview]
Message-ID: <51F6F109.8010102@wwwdotorg.org> (raw)
In-Reply-To: <1374830110-30685-3-git-send-email-josephl@nvidia.com>
On 07/26/2013 03:15 AM, Joseph Lo wrote:
> When suspending to LP1 mode, the SYSCLK will be clock gated. And different
> board may have different polarity of the request of SYSCLK, this patch
> configure the polarity from the DT for the board.
> diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c
> @@ -238,6 +240,20 @@ void tegra_pmc_suspend_init(void)
> reg = tegra_pmc_readl(PMC_CTRL);
> reg |= TEGRA_POWER_CPU_PWRREQ_OE;
> tegra_pmc_writel(reg, PMC_CTRL);
> +
> + reg = tegra_pmc_readl(PMC_CTRL);
> +
> + if (!pmc_pm_data.sysclkreq_high)
> + reg |= TEGRA_POWER_SYSCLK_POLARITY;
> + else
> + reg &= ~TEGRA_POWER_SYSCLK_POLARITY;
> +
> + /* configure the output inverts while the request is tristated */
> + tegra_pmc_writel(reg, PMC_CTRL);
I think s/inverts/polarity/ in that comment would make a lot more sense.
Must _OE be disabled for the code to work correctly? If so, should the
code explicitly clear _OE first, since who knows what state it was
originally in? Can't we just set the new polarity and enable _OE in a
single register write?
> + /* now enable the request */
> + reg |= TEGRA_POWER_SYSCLK_OE;
> + tegra_pmc_writel(reg, PMC_CTRL);
next prev parent reply other threads:[~2013-07-29 22:47 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-26 9:15 [PATCH 0/8] ARM: tegra: support LP1 suspend mode Joseph Lo
2013-07-26 9:15 ` [PATCH 1/8] ARM: tegra: add common resume handling code for LP1 resuming Joseph Lo
2013-07-29 22:38 ` Stephen Warren
2013-07-26 9:15 ` [PATCH 2/8] ARM: tegra: config the polarity of the request of sys clock Joseph Lo
2013-07-29 22:47 ` Stephen Warren [this message]
2013-08-02 7:48 ` Joseph Lo
2013-08-02 20:24 ` Stephen Warren
2013-08-05 8:42 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 3/8] clk: tegra114: add LP1 suspend/resume support Joseph Lo
2013-07-29 22:51 ` Stephen Warren
2013-08-02 8:09 ` Joseph Lo
2013-08-02 20:32 ` Stephen Warren
2013-08-05 8:02 ` Joseph Lo
2013-08-05 17:00 ` Stephen Warren
2013-08-05 17:39 ` Stephen Warren
2013-08-06 9:10 ` Joseph Lo
2013-08-06 18:37 ` Stephen Warren
2013-08-07 9:12 ` Joseph Lo
2013-08-07 16:46 ` Stephen Warren
2013-08-08 2:23 ` Joseph Lo
2013-08-08 19:54 ` Stephen Warren
2013-08-09 9:23 ` Joseph Lo
2013-08-06 9:19 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 4/8] ARM: tegra: add common LP1 suspend support Joseph Lo
2013-07-29 23:13 ` Stephen Warren
2013-08-02 9:27 ` Joseph Lo
2013-08-02 20:40 ` Stephen Warren
2013-08-05 8:07 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 5/8] ARM: tegra30: add " Joseph Lo
2013-07-29 23:45 ` Stephen Warren
2013-08-05 6:46 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 6/8] ARM: tegra20: " Joseph Lo
2013-07-26 9:15 ` [PATCH 7/8] ARM: tegra114: " Joseph Lo
2013-07-29 23:53 ` Stephen Warren
2013-08-05 6:51 ` Joseph Lo
2013-07-26 9:15 ` [PATCH 8/8] ARM: dts: tegra: enable LP1 suspend mode Joseph Lo
2013-07-27 16:12 ` [PATCH 0/8] ARM: tegra: support " Marc Dietrich
2013-07-27 16:20 ` Dmitry Osipenko
2013-07-27 18:09 ` Marc Dietrich
2013-07-27 18:26 ` Dmitry Osipenko
2013-07-27 18:29 ` Dmitry Osipenko
2013-07-27 19:03 ` Marc Dietrich
2013-07-27 19:11 ` Dmitry Osipenko
2013-07-30 9:49 ` Joseph Lo
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