msm: iommu: Rework clock logic and add IOMMU bus clock control

Clean up the clock control code in the probe calls, and add
support for controlling the clock for the IOMMU bus
interconnect. With the (proper) clock driver in place, the
clock control logic in the probe function can be made much
cleaner since it does not have to deal with the placeholder
driver anymore.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Reviewed-by: Trilok Soni <tsoni@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>

1 files changed, 121 insertions, 85 deletions

diff --git a/arch/arm/mach-msm/iommu_dev.c b/arch/arm/mach-msm/iommu_dev.c
index b83c73b41fd1..79ade0b3b326 100644
--- a/arch/arm/mach-msm/iommu_dev.c
+++ b/arch/arm/mach-msm/iommu_dev.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
+/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -29,6 +29,7 @@
 
 #include <mach/iommu_hw-8xxx.h>
 #include <mach/iommu.h>
+#include <mach/clk.h>
 
 struct iommu_ctx_iter_data {
 	/* input */
@@ -130,117 +131,134 @@ static int msm_iommu_probe(struct platform_device *pdev)
 {
 	struct resource *r, *r2;
 	struct clk *iommu_clk;
+	struct clk *iommu_pclk;
 	struct msm_iommu_drvdata *drvdata;
 	struct msm_iommu_dev *iommu_dev = pdev->dev.platform_data;
 	void __iomem *regs_base;
 	resource_size_t	len;
-	int ret = 0, ncb, nm2v, irq;
+	int ret, ncb, nm2v, irq;
 
-	if (pdev->id != -1) {
-		drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
+	if (pdev->id == -1) {
+		msm_iommu_root_dev = pdev;
+		return 0;
+	}
 
-		if (!drvdata) {
-			ret = -ENOMEM;
-			goto fail;
-		}
+	drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
 
-		if (!iommu_dev) {
-			ret = -ENODEV;
-			goto fail;
-		}
+	if (!drvdata) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	if (!iommu_dev) {
+		ret = -ENODEV;
+		goto fail;
+	}
 
-		if (iommu_dev->clk_rate != 0) {
-			iommu_clk = clk_get(&pdev->dev, "iommu_clk");
-
-			if (IS_ERR(iommu_clk)) {
-				ret = -ENODEV;
-				goto fail;
-			}
-
-			if (iommu_dev->clk_rate > 0) {
-				ret = clk_set_rate(iommu_clk,
-							iommu_dev->clk_rate);
-				if (ret) {
-					clk_put(iommu_clk);
-					goto fail;
-				}
-			}
-
-			ret = clk_enable(iommu_clk);
-			if (ret) {
-				clk_put(iommu_clk);
-				goto fail;
-			}
+	iommu_pclk = clk_get(NULL, "smmu_pclk");
+	if (IS_ERR(iommu_pclk)) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	ret = clk_enable(iommu_pclk);
+	if (ret)
+		goto fail_enable;
+
+	iommu_clk = clk_get(&pdev->dev, "iommu_clk");
+
+	if (!IS_ERR(iommu_clk))	{
+		if (clk_get_rate(iommu_clk) == 0)
+			clk_set_min_rate(iommu_clk, 1);
+
+		ret = clk_enable(iommu_clk);
+		if (ret) {
 			clk_put(iommu_clk);
+			goto fail_pclk;
 		}
+	} else
+		iommu_clk = NULL;
 
-		r = platform_get_resource_byname(pdev, IORESOURCE_MEM,
-						 "physbase");
-		if (!r) {
-			ret = -ENODEV;
-			goto fail;
-		}
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "physbase");
 
-		len = r->end - r->start + 1;
+	if (!r) {
+		ret = -ENODEV;
+		goto fail_clk;
+	}
 
-		r2 = request_mem_region(r->start, len, r->name);
-		if (!r2) {
-			pr_err("Could not request memory region: "
-			"start=%p, len=%d\n", (void *) r->start, len);
-			ret = -EBUSY;
-			goto fail;
-		}
+	len = resource_size(r);
 
-		regs_base = ioremap(r2->start, len);
+	r2 = request_mem_region(r->start, len, r->name);
+	if (!r2) {
+		pr_err("Could not request memory region: start=%p, len=%d\n",
+							(void *) r->start, len);
+		ret = -EBUSY;
+		goto fail_clk;
+	}
 
-		if (!regs_base) {
-			pr_err("Could not ioremap: start=%p, len=%d\n",
-				 (void *) r2->start, len);
-			ret = -EBUSY;
-			goto fail_mem;
-		}
+	regs_base = ioremap(r2->start, len);
 
-		irq = platform_get_irq_byname(pdev, "secure_irq");
-		if (irq < 0) {
-			ret = -ENODEV;
-			goto fail_io;
-		}
+	if (!regs_base) {
+		pr_err("Could not ioremap: start=%p, len=%d\n",
+			 (void *) r2->start, len);
+		ret = -EBUSY;
+		goto fail_mem;
+	}
+
+	irq = platform_get_irq_byname(pdev, "secure_irq");
+	if (irq < 0) {
+		ret = -ENODEV;
+		goto fail_io;
+	}
 
-		mb();
+	mb();
 
-		if (GET_IDR(regs_base) == 0) {
-			pr_err("Invalid IDR value detected\n");
-			ret = -ENODEV;
-			goto fail_io;
-		}
+	if (GET_IDR(regs_base) == 0) {
+		pr_err("Invalid IDR value detected\n");
+		ret = -ENODEV;
+		goto fail_io;
+	}
 
-		ret = request_irq(irq, msm_iommu_fault_handler, 0,
-				"msm_iommu_secure_irpt_handler", drvdata);
-		if (ret) {
-			pr_err("Request IRQ %d failed with ret=%d\n", irq, ret);
-			goto fail_io;
-		}
+	ret = request_irq(irq, msm_iommu_fault_handler, 0,
+			"msm_iommu_secure_irpt_handler", drvdata);
+	if (ret) {
+		pr_err("Request IRQ %d failed with ret=%d\n", irq, ret);
+		goto fail_io;
+	}
 
-		msm_iommu_reset(regs_base);
-		drvdata->base = regs_base;
-		drvdata->irq = irq;
+	msm_iommu_reset(regs_base);
+	drvdata->pclk = iommu_pclk;
+	drvdata->clk = iommu_clk;
+	drvdata->base = regs_base;
+	drvdata->irq = irq;
 
-		nm2v = GET_NM2VCBMT((unsigned long) regs_base);
-		ncb = GET_NCB((unsigned long) regs_base);
+	nm2v = GET_NM2VCBMT((unsigned long) regs_base);
+	ncb = GET_NCB((unsigned long) regs_base);
 
-		pr_info("device %s mapped at %p, irq %d with %d ctx banks\n",
+	pr_info("device %s mapped at %p, irq %d with %d ctx banks\n",
 			iommu_dev->name, regs_base, irq, ncb+1);
 
-		platform_set_drvdata(pdev, drvdata);
-	} else
-		msm_iommu_root_dev = pdev;
+	platform_set_drvdata(pdev, drvdata);
 
-	return 0;
+	if (iommu_clk)
+		clk_disable(iommu_clk);
+
+	clk_disable(iommu_pclk);
 
+	return 0;
 fail_io:
 	iounmap(regs_base);
 fail_mem:
 	release_mem_region(r->start, len);
+fail_clk:
+	if (iommu_clk) {
+		clk_disable(iommu_clk);
+		clk_put(iommu_clk);
+	}
+fail_pclk:
+	clk_disable(iommu_pclk);
+fail_enable:
+	clk_put(iommu_pclk);
 fail:
 	kfree(drvdata);
 	return ret;
@@ -252,7 +270,10 @@ static int msm_iommu_remove(struct platform_device *pdev)
 
 	drv = platform_get_drvdata(pdev);
 	if (drv) {
-		memset(drv, 0, sizeof(struct msm_iommu_drvdata));
+		if (drv->clk)
+			clk_put(drv->clk);
+		clk_put(drv->pclk);
+		memset(drv, 0, sizeof(*drv));
 		kfree(drv);
 		platform_set_drvdata(pdev, NULL);
 	}
@@ -264,7 +285,7 @@ static int msm_iommu_ctx_probe(struct platform_device *pdev)
 	struct msm_iommu_ctx_dev *c = pdev->dev.platform_data;
 	struct msm_iommu_drvdata *drvdata;
 	struct msm_iommu_ctx_drvdata *ctx_drvdata = NULL;
-	int i, ret = 0;
+	int i, ret;
 	if (!c || !pdev->dev.parent) {
 		ret = -EINVAL;
 		goto fail;
@@ -288,6 +309,18 @@ static int msm_iommu_ctx_probe(struct platform_device *pdev)
 	INIT_LIST_HEAD(&ctx_drvdata->attached_elm);
 	platform_set_drvdata(pdev, ctx_drvdata);
 
+	ret = clk_enable(drvdata->pclk);
+	if (ret)
+		goto fail;
+
+	if (drvdata->clk) {
+		ret = clk_enable(drvdata->clk);
+		if (ret) {
+			clk_disable(drvdata->pclk);
+			goto fail;
+		}
+	}
+
 	/* Program the M2V tables for this context */
 	for (i = 0; i < MAX_NUM_MIDS; i++) {
 		int mid = c->mids[i];
@@ -310,8 +343,11 @@ static int msm_iommu_ctx_probe(struct platform_device *pdev)
 		SET_NSCFG(drvdata->base, mid, 3);
 	}
 
-	pr_info("context device %s with bank index %d\n", c->name, c->num);
+	if (drvdata->clk)
+		clk_disable(drvdata->clk);
+	clk_disable(drvdata->pclk);
 
+	dev_info(&pdev->dev, "context %s using bank %d\n", c->name, c->num);
 	return 0;
 fail:
 	kfree(ctx_drvdata);