91 lines
2.6 KiB
Diff
91 lines
2.6 KiB
Diff
From 3526403353c2a1b94c3181f900582626d23c339b Mon Sep 17 00:00:00 2001
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From: Linus Walleij <linus.walleij@linaro.org>
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Date: Thu, 18 Aug 2016 20:40:45 +0200
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Subject: mfd: qcom_rpm: Handle message RAM clock
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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The MSM8660, APQ8060, IPQ806x and MSM8960 have a GCC clock
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to the message RAM used by the RPM. This needs to be enabled
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for messages to pass through. This is a crude solution that
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simply prepare/enable at probe() and disable/unprepare
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at remove(). More elaborate PM is probably possible to
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add later.
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The construction uses IS_ERR() to gracefully handle the
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platforms that do not provide a message RAM clock. It will
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bail out of probe only if the clock is hitting a probe
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deferral situation.
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Of course this requires the proper device tree set-up:
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rpm: rpm@104000 {
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compatible = "qcom,rpm-msm8660";
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clocks = <&gcc RPM_MSG_RAM_H_CLK>;
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clock-names = "ram";
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...
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};
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I have provided this in the MSM8660 device tree, and will
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provide patches for the other targets.
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Cc: Björn Andersson <bjorn.andersson@linaro.org>
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Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Signed-off-by: Lee Jones <lee.jones@linaro.org>
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---
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drivers/mfd/qcom_rpm.c | 20 ++++++++++++++++++++
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1 file changed, 20 insertions(+)
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--- a/drivers/mfd/qcom_rpm.c
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+++ b/drivers/mfd/qcom_rpm.c
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@@ -21,6 +21,7 @@
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#include <linux/mfd/qcom_rpm.h>
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#include <linux/mfd/syscon.h>
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#include <linux/regmap.h>
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+#include <linux/clk.h>
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#include <dt-bindings/mfd/qcom-rpm.h>
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@@ -48,6 +49,7 @@ struct qcom_rpm {
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struct regmap *ipc_regmap;
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unsigned ipc_offset;
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unsigned ipc_bit;
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+ struct clk *ramclk;
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struct completion ack;
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struct mutex lock;
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@@ -503,6 +505,20 @@ static int qcom_rpm_probe(struct platfor
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mutex_init(&rpm->lock);
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init_completion(&rpm->ack);
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+ /* Enable message RAM clock */
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+ rpm->ramclk = devm_clk_get(&pdev->dev, "ram");
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+ if (IS_ERR(rpm->ramclk)) {
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+ ret = PTR_ERR(rpm->ramclk);
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+ if (ret == -EPROBE_DEFER)
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+ return ret;
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+ /*
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+ * Fall through in all other cases, as the clock is
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+ * optional. (Does not exist on all platforms.)
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+ */
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+ rpm->ramclk = NULL;
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+ }
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+ clk_prepare_enable(rpm->ramclk); /* Accepts NULL */
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+
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irq_ack = platform_get_irq_byname(pdev, "ack");
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if (irq_ack < 0) {
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dev_err(&pdev->dev, "required ack interrupt missing\n");
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@@ -625,7 +641,11 @@ static int qcom_rpm_probe(struct platfor
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static int qcom_rpm_remove(struct platform_device *pdev)
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{
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+ struct qcom_rpm *rpm = dev_get_drvdata(&pdev->dev);
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+
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of_platform_depopulate(&pdev->dev);
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+ clk_disable_unprepare(rpm->ramclk);
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+
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return 0;
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}
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