ENGR00132894 usb: clk_get should not be called at IRQ context

The old implementation will clk_get/clk_put for each clk on/off operation.
As some clk on/off operation would be IRQ context.
So, it will ocurr the error like "schedule at atomic context".

The new implementation will only call clk_get at usb initialization,
and clk_put at usb de-initialization.
The driver's clock on/off will only call clk_enable/clk_disable.

Signed-off-by: Peter Chen <peter.chen@freescale.com>

3 files changed, 51 insertions, 96 deletions

diff --git a/arch/arm/mach-mx5/usb_dr.c b/arch/arm/mach-mx5/usb_dr.c
index 94ed6c051edc..7863e3898d71 100644
--- a/arch/arm/mach-mx5/usb_dr.c
+++ b/arch/arm/mach-mx5/usb_dr.c
@@ -24,6 +24,10 @@ static int usbotg_init_ext(struct platform_device *pdev);
 static void usbotg_uninit_ext(struct fsl_usb2_platform_data *pdata);
 static void usbotg_clock_gate(bool on);
 
+static struct clk *usb_phy1_clk;
+static struct clk *usb_oh3_clk;
+static struct clk *usb_ahb_clk;
+extern int clk_get_usecount(struct clk *clk);
 /*
  * platform data structs
  * 	- Which one to use is determined by CONFIG options in usb.h
@@ -46,35 +50,31 @@ static int usbotg_init_ext(struct platform_device *pdev)
 {
 	struct clk *usb_clk;
 
+	/* the usb_ahb_clk will be enabled in usb_otg_init */
+	usb_ahb_clk = clk_get(NULL, "usb_ahb_clk");
+
 	usb_clk = clk_get(NULL, "usboh3_clk");
 	clk_enable(usb_clk);
-	clk_put(usb_clk);
+	usb_oh3_clk = usb_clk;
 
-	usb_clk = clk_get(&pdev->dev, "usb_phy1_clk");
+	usb_clk = clk_get(NULL, "usb_phy1_clk");
 	clk_enable(usb_clk);
-	clk_put(usb_clk);
-
-	/*derive clock from oscillator */
-	usb_clk = clk_get(NULL, "usb_utmi_clk");
-	clk_disable(usb_clk);
-	clk_put(usb_clk);
+	usb_phy1_clk = usb_clk;
 
 	return usbotg_init(pdev);
 }
 
 static void usbotg_uninit_ext(struct fsl_usb2_platform_data *pdata)
 {
-	struct clk *usb_clk;
-
-	usb_clk = clk_get(NULL, "usboh3_clk");
-	clk_disable(usb_clk);
-	clk_put(usb_clk);
+	clk_disable(usb_phy1_clk);
+	clk_put(usb_phy1_clk);
 
-	usb_clk = clk_get(&pdata->pdev->dev, "usb_phy1_clk");
-	clk_disable(usb_clk);
-	clk_put(usb_clk);
+	clk_disable(usb_oh3_clk);
+	clk_put(usb_oh3_clk);
 
+	/* usb_ahb_clk will be disabled at usb_common.c */
 	usbotg_uninit(pdata);
+	clk_put(usb_ahb_clk);
 }
 
 /* Below two macros are used at otg mode to indicate usb mode*/
@@ -172,37 +172,15 @@ static void _device_phy_lowpower_suspend(bool enable)
 
 static void usbotg_clock_gate(bool on)
 {
-	struct clk *usb_clk;
-
+	pr_debug("%s: on is %d\n", __func__, on);
 	if (on) {
-		usb_clk = clk_get(NULL, "usb_ahb_clk");
-		clk_enable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usboh3_clk");
-		clk_enable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usb_phy1_clk");
-		clk_enable(usb_clk);
-		clk_put(usb_clk);
-
-		/*derive clock from oscillator */
-		usb_clk = clk_get(NULL, "usb_utmi_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
+		clk_enable(usb_ahb_clk);
+		clk_enable(usb_oh3_clk);
+		clk_enable(usb_phy1_clk);
 	} else {
-		usb_clk = clk_get(NULL, "usb_phy1_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usboh3_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usb_ahb_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
+		clk_disable(usb_phy1_clk);
+		clk_disable(usb_oh3_clk);
+		clk_disable(usb_ahb_clk);
 	}
 }
 
diff --git a/arch/arm/mach-mx5/usb_h1.c b/arch/arm/mach-mx5/usb_h1.c
index ef1b0307e27f..439cf54f50b7 100644
--- a/arch/arm/mach-mx5/usb_h1.c
+++ b/arch/arm/mach-mx5/usb_h1.c
@@ -24,6 +24,10 @@
 #include "usb.h"
 #include "iomux.h"
 #include "mx51_pins.h"
+static struct clk *usb_phy2_clk;
+static struct clk *usb_oh3_clk;
+static struct clk *usb_ahb_clk;
+extern int clk_get_usecount(struct clk *clk);
 /*
  * USB Host1 HS port
  */
@@ -67,7 +71,7 @@ static void gpio_usbh1_inactive(void)
 
 static void _wake_up_enable(struct fsl_usb2_platform_data *pdata, bool enable)
 {
-	printk(KERN_DEBUG "host1, %s, enable is %d\n", __func__, enable);
+	pr_debug("host1, %s, enable is %d\n", __func__, enable);
 	if (enable)
 		USBCTRL |= UCTRL_H1WIE;
 	else {
@@ -88,34 +92,17 @@ static void _phy_lowpower_suspend(bool enable)
 	}
 }
 
-static void usbotg_clock_gate(bool on)
+static void usbh1_clock_gate(bool on)
 {
-	struct clk *usb_clk;
-
+	pr_debug("%s: on is %d\n", __func__, on);
 	if (on) {
-		usb_clk = clk_get(NULL, "usb_ahb_clk");
-		clk_enable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usboh3_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usb_phy2_clk");
-		clk_enable(usb_clk);
-		clk_put(usb_clk);
+		clk_enable(usb_ahb_clk);
+		clk_enable(usb_oh3_clk);
+		clk_enable(usb_phy2_clk);
 	} else {
-		usb_clk = clk_get(NULL, "usb_phy2_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usboh3_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
-
-		usb_clk = clk_get(NULL, "usb_ahb_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
+		clk_disable(usb_phy2_clk);
+		clk_disable(usb_oh3_clk);
+		clk_disable(usb_ahb_clk);
 	}
 }
 
@@ -124,23 +111,21 @@ static int fsl_usb_host_init_ext(struct platform_device *pdev)
 	int ret;
 	struct clk *usb_clk;
 
+	/* the usb_ahb_clk will be enabled in usb_otg_init */
+	usb_ahb_clk = clk_get(NULL, "usb_ahb_clk");
+
 	if (cpu_is_mx53()) {
 		usb_clk = clk_get(NULL, "usboh3_clk");
 		clk_enable(usb_clk);
-		clk_put(usb_clk);
+		usb_oh3_clk = usb_clk;
 
 		usb_clk = clk_get(NULL, "usb_phy2_clk");
 		clk_enable(usb_clk);
-		clk_put(usb_clk);
-
-		/*derive clock from oscillator */
-		usb_clk = clk_get(NULL, "usb_utmi_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
+		usb_phy2_clk = usb_clk;
 	} else if (cpu_is_mx50()) {
 		usb_clk = clk_get(NULL, "usb_phy2_clk");
 		clk_enable(usb_clk);
-		clk_put(usb_clk);
+		usb_phy2_clk = usb_clk;
 	}
 
 	ret = fsl_usb_host_init(pdev);
@@ -165,23 +150,20 @@ static int fsl_usb_host_init_ext(struct platform_device *pdev)
 
 static void fsl_usb_host_uninit_ext(struct fsl_usb2_platform_data *pdata)
 {
-	struct clk *usb_clk;
-
 	if (cpu_is_mx53()) {
-		usb_clk = clk_get(NULL, "usboh3_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
+		clk_disable(usb_oh3_clk);
+		clk_put(usb_oh3_clk);
 
-		usb_clk = clk_get(NULL, "usb_phy2_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
+		clk_disable(usb_phy2_clk);
+		clk_put(usb_phy2_clk);
 	} else if (cpu_is_mx50()) {
-		usb_clk = clk_get(NULL, "usb_phy2_clk");
-		clk_disable(usb_clk);
-		clk_put(usb_clk);
+		clk_disable(usb_phy2_clk);
+		clk_put(usb_phy2_clk);
 	}
 
 	fsl_usb_host_uninit(pdata);
+	/* usb_ahb_clk will be disabled at usb_common.c */
+	clk_put(usb_ahb_clk);
 }
 
 static struct fsl_usb2_platform_data usbh1_config = {
@@ -192,7 +174,7 @@ static struct fsl_usb2_platform_data usbh1_config = {
 	.phy_mode = FSL_USB2_PHY_UTMI_WIDE,
 	.power_budget = 500,	/* 500 mA max power */
 	.wake_up_enable = _wake_up_enable,
-	.usb_clock_for_pm  = usbotg_clock_gate,
+	.usb_clock_for_pm  = usbh1_clock_gate,
 	.phy_lowpower_suspend = _phy_lowpower_suspend,
 	.transceiver = "utmi",
 };
diff --git a/arch/arm/mach-mx5/usb_h2.c b/arch/arm/mach-mx5/usb_h2.c
index 57384f89be02..9acbbf18dd1a 100644
--- a/arch/arm/mach-mx5/usb_h2.c
+++ b/arch/arm/mach-mx5/usb_h2.c
@@ -98,11 +98,6 @@ static int fsl_usb_host_init_ext(struct platform_device *pdev)
 	clk_enable(usb_clk);
 	clk_put(usb_clk);
 
-	/*derive clock from oscillator */
-	usb_clk = clk_get(NULL, "usb_utmi_clk");
-	clk_disable(usb_clk);
-	clk_put(usb_clk);
-
 	/* on mx53, there is a hardware limitation that when switch the host2's clk mode
 	 * ,usb phy1 clk must be on, after finish switching this clk can be off */
 	if (cpu_is_mx53()) {