linux-kernel - [PATCH v2] counter: ti-eqep: enable clock at probe

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Message-ID: <20240621-ti-eqep-enable-clock-v2-1-edd3421b54d4@baylibre.com>
Date: Fri, 21 Jun 2024 17:22:40 -0500
From: David Lechner <dlechner@...libre.com>
To: William Breathitt Gray <wbg@...nel.org>
Cc: David Lechner <dlechner@...libre.com>,
	Judith Mendez <jm@...com>,
	linux-iio@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v2] counter: ti-eqep: enable clock at probe

The TI eQEP clock is both a functional and interface clock. Since it is
required for the device to function, we should be enabling it at probe.

Up to now, we've just been lucky that the clock was enabled by something
else on the system already.

Fixes: f213729f6796 ("counter: new TI eQEP driver")
Reviewed-by: Judith Mendez <jm@...com>
Signed-off-by: David Lechner <dlechner@...libre.com>
---
Changes in v2:
- Added Fixes: tag to commit message
- Picked up Judith's Reviewed-by tag
- Link to v1: https://lore.kernel.org/r/20240609-ti-eqep-enable-clock-v1-1-1e9e7626467e@baylibre.com
---
 drivers/counter/ti-eqep.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
index 072b11fd6b32..825ae22c3ebc 100644
--- a/drivers/counter/ti-eqep.c
+++ b/drivers/counter/ti-eqep.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/clk.h>
 #include <linux/counter.h>
 #include <linux/kernel.h>
 #include <linux/mod_devicetable.h>
@@ -376,6 +377,7 @@ static int ti_eqep_probe(struct platform_device *pdev)
 	struct counter_device *counter;
 	struct ti_eqep_cnt *priv;
 	void __iomem *base;
+	struct clk *clk;
 	int err;
 
 	counter = devm_counter_alloc(dev, sizeof(*priv));
@@ -415,6 +417,10 @@ static int ti_eqep_probe(struct platform_device *pdev)
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);
 
+	clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(clk))
+		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable clock\n");
+
 	err = counter_add(counter);
 	if (err < 0) {
 		pm_runtime_put_sync(dev);

---
base-commit: bb3f1c5fc434b0b177449f7f73ea9b112b397dd1
change-id: 20240609-ti-eqep-enable-clock-91697095ca81