diff options
author | Linus Walleij | 2016-08-18 20:40:45 +0200 |
---|---|---|
committer | Lee Jones | 2016-10-04 15:48:02 +0100 |
commit | 3526403353c2a1b94c3181f900582626d23c339b (patch) | |
tree | 3c784f6e23188b014d6138c867fc3a6d5ad050d4 /drivers | |
parent | 8c5d0571596efa5656cc53144172baa7c5c57b43 (diff) |
mfd: qcom_rpm: Handle message RAM clock
The MSM8660, APQ8060, IPQ806x and MSM8960 have a GCC clock
to the message RAM used by the RPM. This needs to be enabled
for messages to pass through. This is a crude solution that
simply prepare/enable at probe() and disable/unprepare
at remove(). More elaborate PM is probably possible to
add later.
The construction uses IS_ERR() to gracefully handle the
platforms that do not provide a message RAM clock. It will
bail out of probe only if the clock is hitting a probe
deferral situation.
Of course this requires the proper device tree set-up:
rpm: rpm@104000 {
compatible = "qcom,rpm-msm8660";
clocks = <&gcc RPM_MSG_RAM_H_CLK>;
clock-names = "ram";
...
};
I have provided this in the MSM8660 device tree, and will
provide patches for the other targets.
Cc: Björn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/mfd/qcom_rpm.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/mfd/qcom_rpm.c b/drivers/mfd/qcom_rpm.c index d3300714c27b..52fafea06067 100644 --- a/drivers/mfd/qcom_rpm.c +++ b/drivers/mfd/qcom_rpm.c @@ -21,6 +21,7 @@ #include <linux/mfd/qcom_rpm.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> +#include <linux/clk.h> #include <dt-bindings/mfd/qcom-rpm.h> @@ -48,6 +49,7 @@ struct qcom_rpm { struct regmap *ipc_regmap; unsigned ipc_offset; unsigned ipc_bit; + struct clk *ramclk; struct completion ack; struct mutex lock; @@ -552,6 +554,20 @@ static int qcom_rpm_probe(struct platform_device *pdev) mutex_init(&rpm->lock); init_completion(&rpm->ack); + /* Enable message RAM clock */ + rpm->ramclk = devm_clk_get(&pdev->dev, "ram"); + if (IS_ERR(rpm->ramclk)) { + ret = PTR_ERR(rpm->ramclk); + if (ret == -EPROBE_DEFER) + return ret; + /* + * Fall through in all other cases, as the clock is + * optional. (Does not exist on all platforms.) + */ + rpm->ramclk = NULL; + } + clk_prepare_enable(rpm->ramclk); /* Accepts NULL */ + irq_ack = platform_get_irq_byname(pdev, "ack"); if (irq_ack < 0) { dev_err(&pdev->dev, "required ack interrupt missing\n"); @@ -672,7 +688,11 @@ static int qcom_rpm_probe(struct platform_device *pdev) static int qcom_rpm_remove(struct platform_device *pdev) { + struct qcom_rpm *rpm = dev_get_drvdata(&pdev->dev); + of_platform_depopulate(&pdev->dev); + clk_disable_unprepare(rpm->ramclk); + return 0; } |