From abde4ec2e00e724f2f6acb44d66f69dc3a39386d Mon Sep 17 00:00:00 2001
From: Liu Ying <Ying.Liu@freescale.com>
Date: Tue, 2 Aug 2011 12:09:11 +0800
Subject: ENGR00154226-1 IPUv3:Improve driver

1) Fix race condition issue for enable/disable ipu clk.
2) Remove uninitializing MEM_FG_SYNC channel when
   suspend for Android.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
---
 drivers/mxc/ipu3/ipu_capture.c | 148 ++++++++++++++---------------------------
 drivers/mxc/ipu3/ipu_common.c  |  91 +++++++++++++++----------
 drivers/mxc/ipu3/ipu_disp.c    |  32 +++------
 drivers/mxc/ipu3/ipu_prv.h     |   6 +-
 4 files changed, 121 insertions(+), 156 deletions(-)

diff --git a/drivers/mxc/ipu3/ipu_capture.c b/drivers/mxc/ipu3/ipu_capture.c
index 700b32b7e883..da2522751148 100644
--- a/drivers/mxc/ipu3/ipu_capture.c
+++ b/drivers/mxc/ipu3/ipu_capture.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008-2011 Freescale Semiconductor, Inc. All Rights Reserved.
  */
 
 /*
@@ -94,12 +94,7 @@ ipu_csi_init_interface(uint16_t width, uint16_t height, uint32_t pixel_fmt,
 		cfg_param.force_eof << CSI_SENS_CONF_FORCE_EOF_SHIFT |
 		cfg_param.data_en_pol << CSI_SENS_CONF_DATA_EN_POL_SHIFT;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	__raw_writel(data, CSI_SENS_CONF(csi));
@@ -167,6 +162,7 @@ ipu_csi_init_interface(uint16_t width, uint16_t height, uint32_t pixel_fmt,
 		__raw_readl(CSI_ACT_FRM_SIZE(csi)));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 
 	return 0;
 }
@@ -181,9 +177,20 @@ EXPORT_SYMBOL(ipu_csi_init_interface);
  */
 int32_t ipu_csi_get_sensor_protocol(uint32_t csi)
 {
-	return (__raw_readl(CSI_SENS_CONF(csi)) &
+	int32_t ret;
+	unsigned long lock_flags;
+
+	ipu_get_clk(false);
+	spin_lock_irqsave(&ipu_lock, lock_flags);
+
+	ret = (__raw_readl(CSI_SENS_CONF(csi)) &
 		CSI_SENS_CONF_SENS_PRTCL_MASK) >>
 		CSI_SENS_CONF_SENS_PRTCL_SHIFT;
+
+	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
+
+	return ret;
 }
 EXPORT_SYMBOL(ipu_csi_get_sensor_protocol);
 
@@ -250,12 +257,7 @@ void ipu_csi_get_window_size(uint32_t *width, uint32_t *height, uint32_t csi)
 	uint32_t reg;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	reg = __raw_readl(CSI_ACT_FRM_SIZE(csi));
@@ -263,6 +265,7 @@ void ipu_csi_get_window_size(uint32_t *width, uint32_t *height, uint32_t csi)
 	*height = (reg >> 16 & 0xFFFF) + 1;
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 EXPORT_SYMBOL(ipu_csi_get_window_size);
 
@@ -277,17 +280,13 @@ void ipu_csi_set_window_size(uint32_t width, uint32_t height, uint32_t csi)
 {
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	__raw_writel((width - 1) | (height - 1) << 16, CSI_ACT_FRM_SIZE(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 EXPORT_SYMBOL(ipu_csi_set_window_size);
 
@@ -303,12 +302,7 @@ void ipu_csi_set_window_pos(uint32_t left, uint32_t top, uint32_t csi)
 	uint32_t temp;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_OUT_FRM_CTRL(csi));
@@ -317,6 +311,7 @@ void ipu_csi_set_window_pos(uint32_t left, uint32_t top, uint32_t csi)
 	__raw_writel(temp, CSI_OUT_FRM_CTRL(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 EXPORT_SYMBOL(ipu_csi_set_window_pos);
 
@@ -331,12 +326,7 @@ void _ipu_csi_horizontal_downsize_enable(uint32_t csi)
 	uint32_t temp;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_OUT_FRM_CTRL(csi));
@@ -344,6 +334,7 @@ void _ipu_csi_horizontal_downsize_enable(uint32_t csi)
 	__raw_writel(temp, CSI_OUT_FRM_CTRL(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 
 /*!
@@ -357,12 +348,7 @@ void _ipu_csi_horizontal_downsize_disable(uint32_t csi)
 	uint32_t temp;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_OUT_FRM_CTRL(csi));
@@ -370,6 +356,7 @@ void _ipu_csi_horizontal_downsize_disable(uint32_t csi)
 	__raw_writel(temp, CSI_OUT_FRM_CTRL(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 
 /*!
@@ -383,12 +370,7 @@ void _ipu_csi_vertical_downsize_enable(uint32_t csi)
 	uint32_t temp;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_OUT_FRM_CTRL(csi));
@@ -396,6 +378,7 @@ void _ipu_csi_vertical_downsize_enable(uint32_t csi)
 	__raw_writel(temp, CSI_OUT_FRM_CTRL(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 
 /*!
@@ -409,12 +392,7 @@ void _ipu_csi_vertical_downsize_disable(uint32_t csi)
 	uint32_t temp;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_OUT_FRM_CTRL(csi));
@@ -422,6 +400,7 @@ void _ipu_csi_vertical_downsize_disable(uint32_t csi)
 	__raw_writel(temp, CSI_OUT_FRM_CTRL(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 
 /*!
@@ -441,12 +420,7 @@ void ipu_csi_set_test_generator(bool active, uint32_t r_value,
 	uint32_t temp;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_TST_CTRL(csi));
@@ -468,6 +442,7 @@ void ipu_csi_set_test_generator(bool active, uint32_t r_value,
 	}
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 EXPORT_SYMBOL(ipu_csi_set_test_generator);
 
@@ -482,12 +457,6 @@ void _ipu_csi_ccir_err_detection_enable(uint32_t csi)
 {
 	uint32_t temp;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
 	temp = __raw_readl(CSI_CCIR_CODE_1(csi));
 	temp |= CSI_CCIR_ERR_DET_EN;
 	__raw_writel(temp, CSI_CCIR_CODE_1(csi));
@@ -504,12 +473,6 @@ void _ipu_csi_ccir_err_detection_disable(uint32_t csi)
 {
 	uint32_t temp;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
 	temp = __raw_readl(CSI_CCIR_CODE_1(csi));
 	temp &= ~CSI_CCIR_ERR_DET_EN;
 	__raw_writel(temp, CSI_CCIR_CODE_1(csi));
@@ -532,15 +495,10 @@ int _ipu_csi_set_mipi_di(uint32_t num, uint32_t di_val, uint32_t csi)
 
 	if (di_val > 0xFFL) {
 		retval = -EINVAL;
-		goto err;
-	}
-
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
+		goto err1;
 	}
 
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_MIPI_DI(csi));
@@ -568,11 +526,13 @@ int _ipu_csi_set_mipi_di(uint32_t num, uint32_t di_val, uint32_t csi)
 		break;
 	default:
 		retval = -EINVAL;
-		goto err;
+		goto err2;
 	}
 
+err2:
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-err:
+	ipu_put_clk();
+err1:
 	return retval;
 }
 
@@ -598,12 +558,7 @@ int _ipu_csi_set_skip_isp(uint32_t skip, uint32_t max_ratio, uint32_t csi)
 		goto err;
 	}
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_SKIP(csi));
@@ -613,6 +568,7 @@ int _ipu_csi_set_skip_isp(uint32_t skip, uint32_t max_ratio, uint32_t csi)
 	__raw_writel(temp, CSI_SKIP(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 err:
 	return retval;
 }
@@ -641,12 +597,7 @@ int _ipu_csi_set_skip_smfc(uint32_t skip, uint32_t max_ratio,
 		goto err;
 	}
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(CSI_SKIP(csi));
@@ -658,6 +609,7 @@ int _ipu_csi_set_skip_smfc(uint32_t skip, uint32_t max_ratio,
 	__raw_writel(temp, CSI_SKIP(csi));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 err:
 	return retval;
 }
@@ -715,12 +667,7 @@ void _ipu_smfc_set_wmc(ipu_channel_t channel, bool set, uint32_t level)
 	uint32_t temp;
 	unsigned long lock_flags;
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(SMFC_WMC);
@@ -763,12 +710,15 @@ void _ipu_smfc_set_wmc(ipu_channel_t channel, bool set, uint32_t level)
 		}
 		break;
 	default:
-		return;
+		goto out;
+		break;
 	}
 
 	__raw_writel(temp, SMFC_WMC);
 
+out:
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 
 /*!
@@ -783,6 +733,7 @@ void _ipu_smfc_set_burst_size(ipu_channel_t channel, uint32_t bs)
 	uint32_t temp;
 	unsigned long lock_flags;
 
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	temp = __raw_readl(SMFC_BS);
@@ -805,12 +756,15 @@ void _ipu_smfc_set_burst_size(ipu_channel_t channel, uint32_t bs)
 		temp |= bs << SMFC_BS3_SHIFT;
 		break;
 	default:
-		return;
+		goto out;
+		break;
 	}
 
 	__raw_writel(temp, SMFC_BS);
 
+out:
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
+	ipu_put_clk();
 }
 
 /*!
diff --git a/drivers/mxc/ipu3/ipu_common.c b/drivers/mxc/ipu3/ipu_common.c
index 7aa9640aed7a..76d34ce20c60 100644
--- a/drivers/mxc/ipu3/ipu_common.c
+++ b/drivers/mxc/ipu3/ipu_common.c
@@ -45,7 +45,6 @@ struct ipu_irq_node {
 
 /* Globals */
 struct clk *g_ipu_clk;
-bool g_ipu_clk_enabled;
 struct clk *g_di_clk[2];
 struct clk *g_pixel_clk[2];
 struct clk *g_csi_clk[2];
@@ -53,12 +52,14 @@ unsigned char g_dc_di_assignment[10];
 ipu_channel_t g_ipu_csi_channel[2];
 int g_ipu_irq[2];
 int g_ipu_hw_rev;
+int g_ipu_use_count;
 bool g_sec_chan_en[24];
 bool g_thrd_chan_en[24];
 bool g_chan_is_interlaced[52];
 uint32_t g_channel_init_mask;
 uint32_t g_channel_enable_mask;
 DEFINE_SPINLOCK(ipu_lock);
+DEFINE_MUTEX(ipu_clk_lock);
 struct device *g_ipu_dev;
 
 static struct ipu_irq_node ipu_irq_list[IPU_IRQ_COUNT];
@@ -275,6 +276,7 @@ static int ipu_probe(struct platform_device *pdev)
 	unsigned long ipu_base;
 
 	spin_lock_init(&ipu_lock);
+	mutex_init(&ipu_clk_lock);
 
 	g_ipu_hw_rev = plat_data->rev;
 
@@ -419,9 +421,43 @@ int ipu_remove(struct platform_device *pdev)
 	iounmap(ipu_disp_base[1]);
 	iounmap(ipu_vdi_reg);
 
+	mutex_destroy(&ipu_clk_lock);
+
 	return 0;
 }
 
+void ipu_get_clk(bool stop_dvfs)
+{
+	mutex_lock(&ipu_clk_lock);
+
+	g_ipu_use_count++;
+
+	if (g_ipu_use_count == 1) {
+		if (stop_dvfs)
+			stop_dvfs_per();
+		clk_enable(g_ipu_clk);
+	}
+
+	mutex_unlock(&ipu_clk_lock);
+}
+
+void ipu_put_clk(void)
+{
+	mutex_lock(&ipu_clk_lock);
+
+	g_ipu_use_count--;
+
+	if (g_ipu_use_count == 0)
+		clk_disable(g_ipu_clk);
+
+	if (g_ipu_use_count < 0) {
+		dev_err(g_ipu_dev, "ipu use count < 0\n");
+		g_ipu_use_count = 0;
+	}
+
+	mutex_unlock(&ipu_clk_lock);
+}
+
 void ipu_dump_registers(void)
 {
 	printk(KERN_DEBUG "IPU_CONF = \t0x%08X\n", __raw_readl(IPU_CONF));
@@ -493,11 +529,7 @@ int32_t ipu_init_channel(ipu_channel_t channel, ipu_channel_params_t *params)
 	__raw_writel(0xFFFFFFFF, IPU_INT_CTRL(9));
 	__raw_writel(0xFFFFFFFF, IPU_INT_CTRL(10));
 
-	if (g_ipu_clk_enabled == false) {
-		stop_dvfs_per();
-		g_ipu_clk_enabled = true;
-		clk_enable(g_ipu_clk);
-	}
+	ipu_get_clk(true);
 
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
@@ -956,10 +988,7 @@ void ipu_uninit_channel(ipu_channel_t channel)
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
 
-	if (ipu_conf == 0) {
-		clk_disable(g_ipu_clk);
-		g_ipu_clk_enabled = false;
-	}
+	ipu_put_clk();
 
 	WARN_ON(ipu_ic_use_count < 0);
 	WARN_ON(ipu_vdi_use_count < 0);
@@ -2247,9 +2276,7 @@ void ipu_enable_irq(uint32_t irq)
 	uint32_t reg;
 	unsigned long lock_flags;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	reg = __raw_readl(IPUIRQ_2_CTRLREG(irq));
@@ -2257,8 +2284,7 @@ void ipu_enable_irq(uint32_t irq)
 	__raw_writel(reg, IPUIRQ_2_CTRLREG(irq));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
 }
 EXPORT_SYMBOL(ipu_enable_irq);
 
@@ -2274,8 +2300,6 @@ void ipu_disable_irq(uint32_t irq)
 	uint32_t reg;
 	unsigned long lock_flags;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	reg = __raw_readl(IPUIRQ_2_CTRLREG(irq));
@@ -2283,8 +2307,6 @@ void ipu_disable_irq(uint32_t irq)
 	__raw_writel(reg, IPUIRQ_2_CTRLREG(irq));
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
 }
 EXPORT_SYMBOL(ipu_disable_irq);
 
@@ -2297,13 +2319,12 @@ EXPORT_SYMBOL(ipu_disable_irq);
  */
 void ipu_clear_irq(uint32_t irq)
 {
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
+	ipu_get_clk(false);
 
 	__raw_writel(IPUIRQ_2_MASK(irq), IPUIRQ_2_STATREG(irq));
 
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
+
 }
 EXPORT_SYMBOL(ipu_clear_irq);
 
@@ -2320,13 +2341,11 @@ bool ipu_get_irq_status(uint32_t irq)
 {
 	uint32_t reg;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
+	ipu_get_clk(false);
 
 	reg = __raw_readl(IPUIRQ_2_STATREG(irq));
 
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
 
 	if (reg & IPUIRQ_2_MASK(irq))
 		return true;
@@ -2398,7 +2417,9 @@ EXPORT_SYMBOL(ipu_request_irq);
  */
 void ipu_free_irq(uint32_t irq, void *dev_id)
 {
+	ipu_get_clk(false);
 	ipu_disable_irq(irq);	/* disable the interrupt */
+	ipu_put_clk();
 
 	if (ipu_irq_list[irq].dev_id == dev_id)
 		ipu_irq_list[irq].handler = NULL;
@@ -2592,14 +2613,12 @@ EXPORT_SYMBOL(ipu_set_csc_coefficients);
 
 static int ipu_suspend(struct platform_device *pdev, pm_message_t state)
 {
-#ifdef CONFIG_ANDROID
-	ipu_disable_channel(MEM_FG_SYNC, true);
-	ipu_uninit_channel(MEM_FG_SYNC);
-#endif
-
-	if (g_ipu_clk_enabled) {
+	mutex_lock(&ipu_clk_lock);
+	if (g_ipu_use_count > 0) {
 		uint32_t chan_should_disable, timeout = 1000, time = 0;
 
+		dev_err(g_ipu_dev, "ipu suspend with ipu clock enabled\n");
+
 		/* save and disable enabled channels*/
 		idma_enable_reg[0] = __raw_readl(IDMAC_CHA_EN(0));
 		idma_enable_reg[1] = __raw_readl(IDMAC_CHA_EN(32));
@@ -2678,6 +2697,7 @@ static int ipu_suspend(struct platform_device *pdev, pm_message_t state)
 		buf_ready_reg[8] = __raw_readl(IPU_CHA_BUF2_RDY(0));
 		buf_ready_reg[9] = __raw_readl(IPU_CHA_BUF2_RDY(32));
 	}
+	mutex_unlock(&ipu_clk_lock);
 
 	mxc_pg_enable(pdev);
 
@@ -2688,8 +2708,8 @@ static int ipu_resume(struct platform_device *pdev)
 {
 	mxc_pg_disable(pdev);
 
-	if (g_ipu_clk_enabled) {
-
+	mutex_lock(&ipu_clk_lock);
+	if (g_ipu_use_count > 0) {
 		/* restore buf ready regs */
 		__raw_writel(buf_ready_reg[0], IPU_CHA_BUF0_RDY(0));
 		__raw_writel(buf_ready_reg[1], IPU_CHA_BUF0_RDY(32));
@@ -2753,6 +2773,7 @@ static int ipu_resume(struct platform_device *pdev)
 		__raw_writel(0x18800001L, IDMAC_CHA_PRI(0));
 		clk_disable(g_ipu_clk);
 	}
+	mutex_unlock(&ipu_clk_lock);
 
 	return 0;
 }
diff --git a/drivers/mxc/ipu3/ipu_disp.c b/drivers/mxc/ipu3/ipu_disp.c
index bc417abb6723..23fe511c8479 100644
--- a/drivers/mxc/ipu3/ipu_disp.c
+++ b/drivers/mxc/ipu3/ipu_disp.c
@@ -1665,8 +1665,7 @@ int32_t ipu_disp_set_global_alpha(ipu_channel_t channel, bool enable,
 	else
 		bg_chan = false;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	if (bg_chan) {
@@ -1693,8 +1692,7 @@ int32_t ipu_disp_set_global_alpha(ipu_channel_t channel, bool enable,
 	__raw_writel(reg, IPU_SRM_PRI2);
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
 
 	return 0;
 }
@@ -1728,9 +1726,7 @@ int32_t ipu_disp_set_color_key(ipu_channel_t channel, bool enable,
 	else
 		return -EINVAL;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	color_key_4rgb = 1;
@@ -1771,8 +1767,7 @@ int32_t ipu_disp_set_color_key(ipu_channel_t channel, bool enable,
 	__raw_writel(reg, IPU_SRM_PRI2);
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
 
 	return 0;
 }
@@ -1805,8 +1800,7 @@ int32_t ipu_disp_set_gamma_correction(ipu_channel_t channel, bool enable, int co
 	else
 		return -EINVAL;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	for (i = 0; i < 8; i++)
@@ -1829,8 +1823,7 @@ int32_t ipu_disp_set_gamma_correction(ipu_channel_t channel, bool enable, int co
 	__raw_writel(reg, IPU_SRM_PRI2);
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
 
 	return 0;
 }
@@ -1870,9 +1863,7 @@ int32_t ipu_disp_set_window_pos(ipu_channel_t channel, int16_t x_pos,
 	} else
 		return -EINVAL;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
-
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	__raw_writel((x_pos << 16) | y_pos, DP_FG_POS(flow));
@@ -1889,8 +1880,7 @@ int32_t ipu_disp_set_window_pos(ipu_channel_t channel, int16_t x_pos,
 	}
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
 
 	return 0;
 }
@@ -1912,8 +1902,7 @@ int32_t ipu_disp_get_window_pos(ipu_channel_t channel, int16_t *x_pos,
 	else
 		return -EINVAL;
 
-	if (!g_ipu_clk_enabled)
-		clk_enable(g_ipu_clk);
+	ipu_get_clk(false);
 	spin_lock_irqsave(&ipu_lock, lock_flags);
 
 	reg = __raw_readl(DP_FG_POS(flow));
@@ -1922,8 +1911,7 @@ int32_t ipu_disp_get_window_pos(ipu_channel_t channel, int16_t *x_pos,
 	*y_pos = reg & 0x7FF;
 
 	spin_unlock_irqrestore(&ipu_lock, lock_flags);
-	if (!g_ipu_clk_enabled)
-		clk_disable(g_ipu_clk);
+	ipu_put_clk();
 
 	return 0;
 }
diff --git a/drivers/mxc/ipu3/ipu_prv.h b/drivers/mxc/ipu3/ipu_prv.h
index df55b1c8c1f7..8557fbd4e259 100644
--- a/drivers/mxc/ipu3/ipu_prv.h
+++ b/drivers/mxc/ipu3/ipu_prv.h
@@ -22,13 +22,14 @@
 /* Globals */
 extern struct device *g_ipu_dev;
 extern spinlock_t ipu_lock;
-extern bool g_ipu_clk_enabled;
+extern struct mutex ipu_clk_lock;
 extern struct clk *g_ipu_clk;
 extern struct clk *g_di_clk[2];
 extern struct clk *g_pixel_clk[2];
 extern struct clk *g_csi_clk[2];
 extern unsigned char g_dc_di_assignment[];
 extern int g_ipu_hw_rev;
+extern int g_ipu_use_count;
 extern int dmfc_type_setup;
 
 #define IDMA_CHAN_INVALID	0xFF
@@ -51,7 +52,8 @@ enum ipu_dmfc_type {
 int register_ipu_device(void);
 ipu_color_space_t format_to_colorspace(uint32_t fmt);
 bool ipu_pixel_format_has_alpha(uint32_t fmt);
-
+void ipu_get_clk(bool stop_dvfs);
+void ipu_put_clk(void);
 void ipu_dump_registers(void);
 
 uint32_t _ipu_channel_status(ipu_channel_t channel);
-- 
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