From: Anson Huang <b20788@freescale.com>
Date: Mon, 19 Aug 2013 20:49:17 +0000 (-0400)
Subject: ENGR00275542-2 thermal: imx: Add necessary clk operation
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9f77b24905e7fdb1316da3170b748a04b6eb7b30;p=karo-tx-linux.git

ENGR00275542-2 thermal: imx: Add necessary clk operation

Thermal sensor's clock is from pll3_usb_otg 480MHz,
we need to enable it before getting thermal sensor
to work and disable it after thermal sensor stop
working.

Signed-off-by: Anson Huang <b20788@freescale.com>
---

diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 7343476c5964..7e2cea3f581f 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -7,6 +7,7 @@
  *
  */
 
+#include <linux/clk.h>
 #include <linux/cpu_cooling.h>
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
@@ -77,6 +78,7 @@ struct imx_thermal_data {
 	struct regmap *tempmon;
 	unsigned long trip_temp[IMX_TRIP_NUM];
 	u32 c1, c2; /* See formula in imx_get_sensor_data() */
+	struct clk *thermal_clk;
 };
 
 static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
@@ -87,6 +89,7 @@ static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
 	unsigned int n_meas;
 	u32 val;
 
+	clk_prepare_enable(data->thermal_clk);
 	/*
 	 * Every time we measure the temperature, we will power on the
 	 * temperature sensor, enable measurements, take a reading,
@@ -120,6 +123,8 @@ static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
 		last_temp = *temp;
 	}
 
+	clk_disable_unprepare(data->thermal_clk);
+
 	return 0;
 }
 
@@ -344,6 +349,13 @@ static int imx_thermal_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	data->thermal_clk = devm_clk_get(&pdev->dev, NULL);
+	ret = IS_ERR(data->thermal_clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get thermal clk!\n");
+		return ret;
+	}
+
 	/* Make sure sensor is in known good state for measurements */
 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);