msm: iommu: Support alternate core clocks
Refactor the IOMMU clock control code to always require a
core clock as well as an interface clock. Add support for
an optional alternate core clock and update device tree
bindings accordingly. Clean up the probe function to remove
needless enabling / disabling of clocks.
Change-Id: I4d744ffabc1e6fb123bacfda324f64408257cb25
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
diff --git a/Documentation/devicetree/bindings/iommu/msm_iommu.txt b/Documentation/devicetree/bindings/iommu/msm_iommu.txt
index e9fb1a2..f5a2590 100644
--- a/Documentation/devicetree/bindings/iommu/msm_iommu.txt
+++ b/Documentation/devicetree/bindings/iommu/msm_iommu.txt
@@ -16,6 +16,10 @@
- qcom,iommu-smt-size : Number of SMR entries in the SMT of this HW block
- vdd-supply : vdd-supply: phandle to GDSC regulator controlling this IOMMU.
+Optional properties:
+- qcom,needs-alt-core-clk : boolean to enable the secondary core clock for
+ access to the IOMMU configuration registers
+
Example:
qcom,iommu@fda64000 {
diff --git a/arch/arm/mach-msm/include/mach/iommu.h b/arch/arm/mach-msm/include/mach/iommu.h
index 28c53db..b14f145 100644
--- a/arch/arm/mach-msm/include/mach/iommu.h
+++ b/arch/arm/mach-msm/include/mach/iommu.h
@@ -72,6 +72,7 @@
* @irq: Interrupt number
* @clk: The bus clock for this IOMMU hardware instance
* @pclk: The clock for the IOMMU bus interconnect
+ * @aclk: Alternate clock for this IOMMU core, if any
* @name: Human-readable name of this IOMMU device
* @gdsc: Regulator needed to power this HW block (v2 only)
* @nsmr: Size of the SMT on this HW block (v2 only)
@@ -85,6 +86,7 @@
int ttbr_split;
struct clk *clk;
struct clk *pclk;
+ struct clk *aclk;
const char *name;
struct regulator *gdsc;
unsigned int nsmr;
diff --git a/drivers/iommu/msm_iommu-v2.c b/drivers/iommu/msm_iommu-v2.c
index 48edf96..28ad0ff 100644
--- a/drivers/iommu/msm_iommu-v2.c
+++ b/drivers/iommu/msm_iommu-v2.c
@@ -51,10 +51,16 @@
if (ret)
goto fail;
- if (drvdata->clk) {
- ret = clk_prepare_enable(drvdata->clk);
- if (ret)
+ ret = clk_prepare_enable(drvdata->clk);
+ if (ret)
+ clk_disable_unprepare(drvdata->pclk);
+
+ if (drvdata->aclk) {
+ ret = clk_prepare_enable(drvdata->aclk);
+ if (ret) {
+ clk_disable_unprepare(drvdata->clk);
clk_disable_unprepare(drvdata->pclk);
+ }
}
fail:
return ret;
@@ -62,8 +68,9 @@
static void __disable_clocks(struct msm_iommu_drvdata *drvdata)
{
- if (drvdata->clk)
- clk_disable_unprepare(drvdata->clk);
+ if (drvdata->aclk)
+ clk_disable_unprepare(drvdata->aclk);
+ clk_disable_unprepare(drvdata->clk);
clk_disable_unprepare(drvdata->pclk);
}
diff --git a/drivers/iommu/msm_iommu_dev-v2.c b/drivers/iommu/msm_iommu_dev-v2.c
index 14ed5d9..8c26f95 100644
--- a/drivers/iommu/msm_iommu_dev-v2.c
+++ b/drivers/iommu/msm_iommu_dev-v2.c
@@ -69,7 +69,7 @@
{
struct msm_iommu_drvdata *drvdata;
struct resource *r;
- int ret;
+ int ret, needs_alt_core_clk;
if (msm_iommu_root_dev == pdev)
return 0;
@@ -93,55 +93,42 @@
if (IS_ERR(drvdata->gdsc))
return -EINVAL;
- drvdata->pclk = clk_get(&pdev->dev, "iface_clk");
+ drvdata->pclk = devm_clk_get(&pdev->dev, "iface_clk");
if (IS_ERR(drvdata->pclk))
return PTR_ERR(drvdata->pclk);
- ret = clk_prepare_enable(drvdata->pclk);
- if (ret)
- goto fail_enable;
+ drvdata->clk = devm_clk_get(&pdev->dev, "core_clk");
+ if (IS_ERR(drvdata->clk))
+ return PTR_ERR(drvdata->clk);
- drvdata->clk = clk_get(&pdev->dev, "core_clk");
- if (!IS_ERR(drvdata->clk)) {
- if (clk_get_rate(drvdata->clk) == 0) {
- ret = clk_round_rate(drvdata->clk, 1);
- clk_set_rate(drvdata->clk, ret);
- }
+ needs_alt_core_clk = of_property_read_bool(pdev->dev.of_node,
+ "qcom,needs-alt-core-clk");
+ if (needs_alt_core_clk) {
+ drvdata->aclk = devm_clk_get(&pdev->dev, "alt_core_clk");
+ if (IS_ERR(drvdata->aclk))
+ return PTR_ERR(drvdata->aclk);
+ }
- ret = clk_prepare_enable(drvdata->clk);
- if (ret) {
- clk_put(drvdata->clk);
- goto fail_pclk;
- }
- } else
- drvdata->clk = NULL;
+ if (clk_get_rate(drvdata->clk) == 0) {
+ ret = clk_round_rate(drvdata->clk, 1);
+ clk_set_rate(drvdata->clk, ret);
+ }
+
+ if (drvdata->aclk && clk_get_rate(drvdata->aclk) == 0) {
+ ret = clk_round_rate(drvdata->aclk, 1);
+ clk_set_rate(drvdata->aclk, ret);
+ }
ret = msm_iommu_parse_dt(pdev, drvdata);
if (ret)
- goto fail_clk;
+ return ret;
pr_info("device %s mapped at %p, with %d ctx banks\n",
drvdata->name, drvdata->base, drvdata->ncb);
platform_set_drvdata(pdev, drvdata);
- if (drvdata->clk)
- clk_disable_unprepare(drvdata->clk);
-
- clk_disable_unprepare(drvdata->pclk);
-
return 0;
-
-fail_clk:
- if (drvdata->clk) {
- clk_disable_unprepare(drvdata->clk);
- clk_put(drvdata->clk);
- }
-fail_pclk:
- clk_disable_unprepare(drvdata->pclk);
-fail_enable:
- clk_put(drvdata->pclk);
- return ret;
}
static int __devexit msm_iommu_remove(struct platform_device *pdev)