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| Path | csiph.com!eternal-september.org!feeder.eternal-september.org!aioe.org!gothmog.csi.it!bofh.it!news.nic.it!robomod |
|---|---|
| From | Boris Brezillon <boris.brezillon@free-electrons.com> |
| Newsgroups | linux.kernel |
| Subject | [PATCH v3 08/14] pwm: sti: Avoid glitches on already running PWMs |
| Date | Tue, 14 Jun 2016 11:20:02 +0200 |
| Message-ID | <rJSFQ-2Rh-43@gated-at.bofh.it> (permalink) |
| References | <rJSFP-2Rh-5@gated-at.bofh.it> |
| X-Mailer | git-send-email 2.7.4 |
| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 52 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | Heiko Stuebner <heiko@sntech.de>, linux-rockchip@lists.infradead.org, Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim <milo.kim@ti.com>, Doug Anderson <dianders@google.com>, Caesar Wang <wxt@rock-chips.com>, Stephen Barber <smbarber@chromium.org>, Brian Norris <briannorris@chromium.org>, Ajit Pal Singh <ajitpal.singh@st.com>, Srinivas Kandagatla <srinivas.kandagatla@gmail.com>, Maxime Coquelin <maxime.coquelin@st.com>, Patrice Chotard <patrice.chotard@st.com>, kernel@stlinux.com, Laxman Dewangan <ldewangan@nvidia.com>, Boris Brezillon <boris.brezillon@free-electrons.com> |
| X-Original-Date | Tue, 14 Jun 2016 11:13:16 +0200 |
| X-Original-Message-ID | <1465895602-31008-9-git-send-email-boris.brezillon@free-electrons.com> |
| X-Original-References | <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1421706 |
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The current logic will disable the PWM clk even if a PWM was left
enabled by the bootloader (because it's controlling a critical device
like a regulator for example).
Keep the PWM clk enabled if at least one PWM is enabled to avoid any
glitches.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/pwm/pwm-sti.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c
index 6300d3e..5bda51d 100644
--- a/drivers/pwm/pwm-sti.c
+++ b/drivers/pwm/pwm-sti.c
@@ -340,7 +340,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
struct sti_pwm_compat_data *cdata;
struct sti_pwm_chip *pc;
struct resource *res;
- int ret;
+ int i, ret;
pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
@@ -391,7 +391,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
return -EINVAL;
}
- ret = clk_prepare(pc->clk);
+ ret = clk_prepare_enable(pc->clk);
if (ret) {
dev_err(dev, "failed to prepare clock\n");
return ret;
@@ -409,6 +409,16 @@ static int sti_pwm_probe(struct platform_device *pdev)
return ret;
}
+ /*
+ * Keep the PWM clk enabled if some PWMs appear to be up and
+ * running.
+ */
+ for (i = 0; i < pc->chip.npwm; i++) {
+ if (pwm_is_enabled(&pc->chip.pwms[i]))
+ clk_enable(pc->clk);
+ }
+ clk_disable(pc->clk);
+
platform_set_drvdata(pdev, pc);
return 0;
--
2.7.4
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[PATCH v3 00/14] regulator: pwm: various improvements Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200 [PATCH v3 04/14] pwm: rockchip: Add support for hardware readout Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200 [PATCH v3 05/14] pwm: rockchip: Avoid glitches on already running PWMs Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200 [PATCH v3 09/14] regulator: pwm: Adjust PWM config at probe time Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200 [PATCH v3 02/14] pwm: Add two helpers to ease relative duty cycle manipulation Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200 [PATCH v3 08/14] pwm: sti: Avoid glitches on already running PWMs Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200 [PATCH v3 13/14] regulator: pwm: Support extra continuous mode cases Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200 [PATCH v3 03/14] pwm: rockchip: Fix period and duty_cycle approximation Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-14 11:20 +0200
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