linux-kernel - [PATCH 4/5] irqchip/gic-pm: use devm_clk

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Date:   Wed, 13 Mar 2019 16:32:35 +0530
From:   Sameer Pujar <spujar@...dia.com>
To:     <tglx@...utronix.de>, <jason@...edaemon.net>,
        <marc.zyngier@....com>, <will.deacon@....com>,
        <catalin.marinas@....com>, <heiko@...ech.de>,
        <horms+renesas@...ge.net.au>, <maxime.ripard@...tlin.com>,
        <andy.gross@...aro.org>, <olof@...om.net>,
        <bjorn.andersson@...aro.org>, <jagan@...rulasolutions.com>,
        <enric.balletbo@...labora.com>, <stefan.wahren@...e.com>,
        <ezequiel@...labora.com>, <marc.w.gonzalez@...e.fr>,
        <christoffer.dall@....com>, <drjones@...hat.com>,
        <julien.thierry@....com>
CC:     <treding@...dia.com>, <jonathanh@...dia.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, Sameer Pujar <spujar@...dia.com>
Subject: [PATCH 4/5] irqchip/gic-pm: use devm_clk_*() helpers

irq-gic-pm driver is using pm_clk_*() interface to manage clock resources.
With this, clocks always remain ON. This happens on Tegra devices which use
BPMP co-processor to manage clocks, where clocks are enabled during prepare
phase. This is necessary because calls to BPMP are always blocking. When
pm_clk_*() interface is used on such devices, clock prepare count is not
balanced till driver remove() gets executed and hence clocks are seen ON
always. This patch replaces pm_clk_*() with devm_clk_*() framework.

Suggested-by: Mohan Kumar D <mkumard@...dia.com>
Signed-off-by: Sameer Pujar <spujar@...dia.com>
Reviewed-by: Jonathan Hunter <jonathanh@...dia.com>
---
 drivers/irqchip/irq-gic-pm.c | 52 +++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 20 deletions(-)

diff --git a/drivers/irqchip/irq-gic-pm.c b/drivers/irqchip/irq-gic-pm.c
index cde9714..b5405df 100644
--- a/drivers/irqchip/irq-gic-pm.c
+++ b/drivers/irqchip/irq-gic-pm.c
@@ -19,7 +19,6 @@
 #include <linux/of_irq.h>
 #include <linux/irqchip/arm-gic.h>
 #include <linux/platform_device.h>
-#include <linux/pm_clock.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 
@@ -30,6 +29,8 @@ struct gic_clk_data {
 
 struct gic_chip_pm {
 	struct gic_chip_data *chip_data;
+	const struct gic_clk_data *clk_data;
+	struct clk **clk_handle;
 	int irq;
 };
 
@@ -37,11 +38,19 @@ static int gic_runtime_resume(struct device *dev)
 {
 	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
 	struct gic_chip_data *gic = chip_pm->chip_data;
-	int ret;
+	const struct gic_clk_data *data = chip_pm->clk_data;
+	int ret, i;
 
-	ret = pm_clk_resume(dev);
-	if (ret)
-		return ret;
+	for (i = 0; i < data->num_clocks; i++) {
+		ret = clk_prepare_enable(chip_pm->clk_handle[i]);
+		if (ret) {
+			while (--i >= 0)
+				clk_disable_unprepare(chip_pm->clk_handle[i]);
+
+			dev_err(dev, " clk_enable failed: %d\n", ret);
+			return ret;
+		}
+	}
 
 	/*
 	 * On the very first resume, the pointer to the driver data
@@ -62,32 +71,37 @@ static int gic_runtime_suspend(struct device *dev)
 {
 	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
 	struct gic_chip_data *gic = chip_pm->chip_data;
+	const struct gic_clk_data *data = chip_pm->clk_data;
+	int i;
 
 	gic_dist_save(gic);
 	gic_cpu_save(gic);
 
-	return pm_clk_suspend(dev);
+	for (i = 0; i < data->num_clocks; i++)
+		clk_disable_unprepare(chip_pm->clk_handle[i]);
+
+	return 0;
 }
 
-static int gic_get_clocks(struct device *dev, const struct gic_clk_data *data)
+static int gic_get_clocks(struct device *dev, struct gic_chip_pm *chip_pm)
 {
 	unsigned int i;
-	int ret;
+	const struct gic_clk_data *data = chip_pm->clk_data;
 
 	if (!dev || !data)
 		return -EINVAL;
 
-	ret = pm_clk_create(dev);
-	if (ret)
-		return ret;
+	chip_pm->clk_handle = devm_kzalloc(dev, data->num_clocks *
+					   sizeof(struct clk *), GFP_KERNEL);
+	if (!chip_pm->clk_handle)
+		return -ENOMEM;
 
 	for (i = 0; i < data->num_clocks; i++) {
-		ret = of_pm_clk_add_clk(dev, data->clocks[i]);
-		if (ret) {
+		chip_pm->clk_handle[i] = devm_clk_get(dev, data->clocks[i]);
+		if (IS_ERR(chip_pm->clk_handle[i])) {
 			dev_err(dev, "failed to add clock %s\n",
 				data->clocks[i]);
-			pm_clk_destroy(dev);
-			return ret;
+			return PTR_ERR(chip_pm->clk_handle[i]);
 		}
 	}
 
@@ -111,6 +125,8 @@ static int gic_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "no device match found\n");
 		return -ENODEV;
 	}
+	chip_pm->clk_data = data;
+	platform_set_drvdata(pdev, chip_pm);
 
 	irq = irq_of_parse_and_map(dev->of_node, 0);
 	if (!irq) {
@@ -118,7 +134,7 @@ static int gic_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	ret = gic_get_clocks(dev, data);
+	ret = gic_get_clocks(dev, chip_pm);
 	if (ret)
 		goto irq_dispose;
 
@@ -132,8 +148,6 @@ static int gic_probe(struct platform_device *pdev)
 	if (ret)
 		goto rpm_put;
 
-	platform_set_drvdata(pdev, chip_pm);
-
 	pm_runtime_put(dev);
 
 	chip_pm->irq = irq;
@@ -145,7 +159,6 @@ static int gic_probe(struct platform_device *pdev)
 	pm_runtime_put_sync(dev);
 rpm_disable:
 	pm_runtime_disable(dev);
-	pm_clk_destroy(dev);
 irq_dispose:
 	irq_dispose_mapping(irq);
 
@@ -159,7 +172,6 @@ static int gic_remove(struct platform_device *pdev)
 
 	pm_runtime_force_suspend(&pdev->dev);
 	gic_teardown(gic);
-	pm_clk_destroy(&pdev->dev);
 	irq_dispose_mapping(chip_pm->irq);
 
 	return 0;
-- 
2.7.4