[PATCH v2] thermal: exynos: add special clock support

From: Abhilash Kesavan
Date: Tue Nov 25 2014 - 19:51:21 EST


Exynos7 has a special clock required for the functional operation
of the TMU that is not present in earlier SoCs. Add support for
this clock and update the binding documentation.

Signed-off-by: Abhilash Kesavan <a.kesavan@xxxxxxxxxxx>
---
Changes since v1:
- Added a per-soc flag to indicate the presence of special clock
- Changed the name of special clock from "tmu_sclk" to "sclk"
- Fixed the error handling for sclk

Tested on 5420 and 5800 based chromebooks, no change in existing behavior.

.../devicetree/bindings/thermal/exynos-thermal.txt | 3 ++
drivers/thermal/samsung/exynos_tmu.c | 31 ++++++++++++++++----
2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
index ae738f5..acf4705 100644
--- a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
+++ b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
@@ -32,10 +32,13 @@
- clocks : The main clocks for TMU device
-- 1. operational clock for TMU channel
-- 2. optional clock to access the shared registers of TMU channel
+ -- 3. optional special clock for functional operation
- clock-names : Thermal system clock name
-- "tmu_apbif" operational clock for current TMU channel
-- "tmu_triminfo_apbif" clock to access the shared triminfo register
for current TMU channel
+ -- "sclk" clock for functional operation of the current TMU
+ channel
- vtmu-supply: This entry is optional and provides the regulator node supplying
voltage to TMU. If needed this entry can be placed inside
board/platform specific dts file.
diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index d44d91d..8ed8409 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -123,11 +123,14 @@
* @base: base address of the single instance of the TMU controller.
* @base_second: base address of the common registers of the TMU controller.
* @irq: irq number of the TMU controller.
+ * @needs_sclk: SoC specific flag indicating that sclk is required for
+ functional operation of the TMU controller.
* @soc: id of the SOC type.
* @irq_work: pointer to the irq work structure.
* @lock: lock to implement synchronization.
* @clk: pointer to the clock structure.
* @clk_sec: pointer to the clock structure for accessing the base_second.
+ * @sclk: pointer to the clock structure for accessing the tmu special clock.
* @temp_error1: fused value of the first point trim.
* @temp_error2: fused value of the second point trim.
* @regulator: pointer to the TMU regulator structure.
@@ -144,10 +147,11 @@ struct exynos_tmu_data {
void __iomem *base;
void __iomem *base_second;
int irq;
+ bool needs_sclk;
enum soc_type soc;
struct work_struct irq_work;
struct mutex lock;
- struct clk *clk, *clk_sec;
+ struct clk *clk, *clk_sec, *sclk;
u8 temp_error1, temp_error2;
struct regulator *regulator;
struct thermal_sensor_conf *reg_conf;
@@ -883,10 +887,24 @@ static int exynos_tmu_probe(struct platform_device *pdev)
goto err_clk_sec;
}

+ if (data->needs_sclk) {
+ data->sclk = devm_clk_get(&pdev->dev, "sclk");
+ if (IS_ERR(data->sclk)) {
+ dev_err(&pdev->dev, "Failed to get sclk\n");
+ goto err_clk;
+ } else {
+ ret = clk_prepare_enable(data->sclk);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to enable sclk\n");
+ goto err_clk;
+ }
+ }
+ }
+
ret = exynos_tmu_initialize(pdev);
if (ret) {
dev_err(&pdev->dev, "Failed to initialize TMU\n");
- goto err_clk;
+ goto err_sclk;
}

exynos_tmu_control(pdev, true);
@@ -896,7 +914,7 @@ static int exynos_tmu_probe(struct platform_device *pdev)
sizeof(struct thermal_sensor_conf), GFP_KERNEL);
if (!sensor_conf) {
ret = -ENOMEM;
- goto err_clk;
+ goto err_sclk;
}
sprintf(sensor_conf->name, "therm_zone%d", data->id);
sensor_conf->read_temperature = (int (*)(void *))exynos_tmu_read;
@@ -928,7 +946,7 @@ static int exynos_tmu_probe(struct platform_device *pdev)
ret = exynos_register_thermal(sensor_conf);
if (ret) {
dev_err(&pdev->dev, "Failed to register thermal interface\n");
- goto err_clk;
+ goto err_sclk;
}
data->reg_conf = sensor_conf;

@@ -936,10 +954,12 @@ static int exynos_tmu_probe(struct platform_device *pdev)
IRQF_TRIGGER_RISING | IRQF_SHARED, dev_name(&pdev->dev), data);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq: %d\n", data->irq);
- goto err_clk;
+ goto err_sclk;
}

return 0;
+err_sclk:
+ clk_disable_unprepare(data->sclk);
err_clk:
clk_unprepare(data->clk);
err_clk_sec:
@@ -956,6 +976,7 @@ static int exynos_tmu_remove(struct platform_device *pdev)

exynos_tmu_control(pdev, false);

+ clk_disable_unprepare(data->sclk);
clk_unprepare(data->clk);
if (!IS_ERR(data->clk_sec))
clk_unprepare(data->clk_sec);
--
1.7.9.5

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